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Sample records for superrefractory ree patterns

  1. Reaction of seawater with fresh mid-ocean ridge gabbro creates ';atypical' REE pattern and high REE fluid fluxes: Experiments at 425 and 475 °C, 400 and 1000 bar

    Science.gov (United States)

    Beermann, O.; Garbe-Schönberg, D.; Holzheid, A. D.

    2013-12-01

    High-temperature MOR hydrothermalism significantly affects ocean chemistry. The Sisters Peak (SP) hydrothermal field at 5°S on the slow-spreading Mid-Atlantic Ridge (MAR) emanates fluids >400°C [1] that have high concentrations of H2, transition metals, and rare earth elements (REE) exhibiting ';atypical' REE pattern characterized by depletions of LREE and HREE relative to MREE and no Eu anomaly [2]. This is in contrast to the ';typical' LREE enrichment and strong positive Eu anomaly known from many MOR vent fluids observed world-wide [e.g., 3]. Besides temperature, the seawater-to-rock ratio (w/r ratio) has significant control on the fluid chemistry [e.g., 4, 5]. To understand how vent fluid REE-signatures are generated during water-rock interaction processes we reacted unaltered gabbro with natural bottom seawater at 425 °C and 400 bar and at 425 and 475 °C at 1000 bar at variable w/r (mass) ratios ranging from 0.5-10 by using cold seal pressure vessels (CSPV). The run durations varied from 3-72 h. Reacted fluids were analysed for major and trace elements by ICP-OES and ICP-MS. In our experiments, ';atypical' REE fluid pattern similar to those of SP fluids were obtained at high w/r ratio (5 and 10) that might be characteristic for focused fluid-flow along e.g., detachment faults at slow-spreading MOR [6]. In contrast, more ';typical'-like REE pattern with elevated LREE and slightly positive Eu anomalies have been reproduced at low w/r ratio (0.5-1). Results of numerical simulations imply that strong positive Eu anomalies of fluids and altered gabbro from high temperature MOR hydrothermal systems can be created by intense rock leaching processes at high w/r ratio (5-10). This suggests that hydrothermal circulation through the ocean crust creates ';typical' REE fluid pattern with strong positive Eu anomalies if seawater reacts with gabbroic host rock that has been already leached in REE at high fluid fluxes. Simulations of the temporal chemical evolution of

  2. Nd isotopic composition and REE pattern in the surface waters of the eastern Indian Ocean and its adjacent seas

    Energy Technology Data Exchange (ETDEWEB)

    Amakawa, Hiroshi; Alibo, D.S.; Nozaki, Yoshiyuki

    2000-05-01

    The Nd isotopic composition and dissolved rare earth elements (REEs) have been measured in the surface waters along the 1996/97 R.V. Hakuho-Maru Expedition route from Tokyo to the Southern Ocean, southwest of Australia, through the Philippine and Indonesian Archipelago, the eastern Indian Ocean, the Bay of Bengal and the South China Sea. The radiogenic {epsilon}{sub Nd} values of {minus}1.3 and {minus}1.4 were found in the Sulu Sea and near the Lombok Strait, indicating the strong influence of surrounding volcanic islands, whereas non-radiogenic {epsilon}{sub Nd} values of less than {minus}10 were found in the Southern Ocean and the Bay of Bengal suggesting Nd of continental origin. The dissolved Nd concentrations also showed a wide range of variation from 2.8 to 19.6 pmol/kg and the trivalent REE patterns exhibited characteristic features that can be grouped into each different oceanic province. The geographical distribution of dissolved Nd is different from that of atmospherically derived {sup 210}Pb, but generally resembles that of coastally derived {sup 228}Ra. This strongly suggests that fluvial and coastal input predominates over eolian input for dissolved Nd in the surface ocean. However, the riverine dissolved Nd flux appears to be relatively minor, and remobilization of Nd from coastal and shelf sediments may play an important role in the total Nd input to the ocean. By modeling the distributions of the isotopic composition and concentration of Nd together with the activity ratio of {sup 228}Ra/{sup 226}Ra in the southeastern Indian Ocean, the authors estimate a mean residence time of Nd in the surface mixed layer to be 1.5--2.6 years. The short mean residence time is comparable with, or slightly longer than that of {sup 210}Pb suggesting similar chemical reactivity.

  3. Dust dispersal and Pb enrichment at the rare-metal Orlovka-Spokoinoe mining and ore processing site: insights from REE patterns and elemental ratios.

    Science.gov (United States)

    Dolgopolova, Alla; Weiss, Dominik J; Seltmann, Reimar; Dulski, Peter

    2006-04-30

    Different geological, technogenic and environmental samples from the Orlovka-Spokoinoe Ta-Nb-Sn-W mining site and ore processing complex in Eastern Transbaikalia (Russia), were analysed for Pb, Y, Zr, Hf and rare earth elements (REE) to assess the effect of dust and metal dispersal on the environment within the Orlovka-Spokoinoe mining site. Potential source material analysed included ore-bearing and barren granites, host rocks, tailing pond sediments, and ore concentrates. Lichens and birch leaves were used as receptor samples. The REE enrichment relative to chondrite, the extent of the Eu anomalies, the enrichments of heavy REE (HREE), and Zr/Hf and Yb/Y ratios suggest that tailings, barren granites, and metasedimentary host rocks are the main sources of dust in the studied mining environment. In addition, calculated lead enrichment (relative to host rocks) suggests that the environment is polluted with Pb. Our results clearly demonstrate the potential of REE patterns and elemental ratios as a reliable technique to trace dust and metals sources and dispersal within a confined mining area offering a new tool for environmental assessment studies.

  4. Dust dispersal and Pb enrichment at the rare-metal Orlovka-Spokoinoe mining and ore processing site: Insights from REE patterns and elemental ratios

    Energy Technology Data Exchange (ETDEWEB)

    Dolgopolova, Alla [Centre for Russian and Central EurAsian Mineral Studies (CERCAMS), Department of Mineralogy, Natural History Museum, Cromwell Road, London SW7 5BD (United Kingdom)]. E-mail: allad@nhm.ac.uk; Weiss, Dominik J. [Centre for Russian and Central EurAsian Mineral Studies (CERCAMS), Department of Mineralogy, Natural History Museum, Cromwell Road, London SW7 5BD (United Kingdom); Department of Earth Science and Engineering, Imperial College London, London SW7 2AZ (United Kingdom); Seltmann, Reimar [Centre for Russian and Central EurAsian Mineral Studies (CERCAMS), Department of Mineralogy, Natural History Museum, Cromwell Road, London SW7 5BD (United Kingdom); Dulski, Peter [GFZ Potsdam, Telegrafenberg, D-14473 Potsdam (Germany)

    2006-04-30

    Different geological, technogenic and environmental samples from the Orlovka-Spokoinoe Ta-Nb-Sn-W mining site and ore processing complex in Eastern Transbaikalia (Russia), were analysed for Pb, Y, Zr, Hf and rare earth elements (REE) to assess the effect of dust and metal dispersal on the environment within the Orlovka-Spokoinoe mining site. Potential source material analysed included ore-bearing and barren granites, host rocks, tailing pond sediments, and ore concentrates. Lichens and birch leaves were used as receptor samples. The REE enrichment relative to chondrite, the extent of the Eu anomalies, the enrichments of heavy REE (HREE), and Zr/Hf and Yb/Y ratios suggest that tailings, barren granites, and metasedimentary host rocks are the main sources of dust in the studied mining environment. In addition, calculated lead enrichment (relative to host rocks) suggests that the environment is polluted with Pb. Our results clearly demonstrate the potential of REE patterns and elemental ratios as a reliable technique to trace dust and metals sources and dispersal within a confined mining area offering a new tool for environmental assessment studies.

  5. REE and

    Institute of Scientific and Technical Information of China (English)

    LIU; Jihua

    2005-01-01

    elements in the sedimentary cycle: A summary, Chemistry Geology, 1974, 14: 285-304.[13]Piper, D. Z., Rare earth elements in ferromanganese nodules and other marine phase, Geochim. Cosmochim. Acta, 1974, 38: 1007-1023.[14]Fleet, A. J., Aqueous and sedimentary geochemistry of rare earth elements, in Rare Earth Elements Geochemistry (ed. Henderson, P.), Amsterdam: Elsevier, 1984, 343-421.[15]Faure, G., Principles of Isotope Geology, New York: John Wiley & Sons, 1986, 117-248.[16]Tlig, S., Steinberg, M., Distribution of rare earth elements (REE) in size fractions of recent sediments of the Indian Ocean, Chemical Geology, 1982, 37: 317-333.[17]Toyoda, K., Nakamura, Y., Masuda, A., Rare earth elements of Pacific pelagic sediments, Geochim. Cosmochim. Acta, 1990, 54: 1093-1103.[18]Liu Jihua, Liang Hongfeng, Xia Ning et al., REE geochemistry of fractions less than 2 μm in pelagic sediments from the eastern Pacific, Geochimica (in Chinese), 1998, 27(1): 49-58.[19]Goldstein, S., O'Nions, R. K., Nd and Sr isotopic relationships in pelagic clay and ferromanganese deposits, Nature, 1981, 292: 324-327.[20]Jones, C. E., Halliday, A. N., Rea D. K. et al., Neodymium isotopic variations in North Pacific modern silicate sediment and the insignificance of detrital REE contributions to seawater, Earth Planet Sci. Lett., 1994, 127: 55-66.[21]Dean, W. E., Leinen, M., Stow, D. A. V., Classification of deep-sea fine-grained sediments, Journal of Sedimentary Petrology, 1985, 55: 250-256.[22]Biscaye, P. E., Mineralogy and sedimentation of recent deep-sea clay in the Atlantic Ocean and adjacent seas and oceans, Geological Society of American Bulletin, 1965, 76: 803-832.[23]Wang Zhonggang, Yu Xueyuan, Zhao Zhenhua et al., Rare Earth Element Geochemistry (in Chinese), Beijing: Science Press, 1989, 88-93.[24]Haskin, L. A., Haskin, M. A., Frey, F. A. et al., Relative and absolute terrestrial abundances of the rare earths, in: Origin and Distribution of

  6. Super-Refractory Status Epilepticus: Report of a Case and Review of the Literature.

    Science.gov (United States)

    Lapenta, Leonardo; Frisullo, Giovanni; Vollono, Catello; Brunetti, Valerio; Giannantoni, Nadia Mariagrazia; Sandroni, Claudio; Di Lella, Giuseppe; Della Marca, Giacomo

    2015-10-01

    Super-refractory status epilepticus (SE; ie, SE continuing or recurring despite 24 hours of general anesthesia) is a severe condition with high percentage of mortality and morbidity. Usually, this condition occurs because of serious brain damage; nevertheless, some patients develop super-refractory SE without identifiable etiology. Although not uncommonly encountered in neurointensive care, scientific data on this condition are still lacking in terms of treatment and prognosis. Herein, we report a case of super-refractory SE with recovery after 50 days, despite electroencephalographic (EEG) and magnetic resonance imaging (MRI) signs traditionally related to poor prognosis. A review of the literature on super-refractory SE is also presented.

  7. Ketogenic diet treatment for pediatric super-refractory status epilepticus.

    Science.gov (United States)

    Appavu, Brian; Vanatta, Lisa; Condie, John; Kerrigan, John F; Jarrar, Randa

    2016-10-01

    We aimed to study whether ketogenic diet (KD) therapy leads to resolution of super-refractory status epilepticus in pediatric patients without significant harm. A retrospective review was performed at Phoenix Children's Hospital on patients with super-refractory status epilepticus undergoing ketogenic diet therapy from 2011 to 2015. Ten children with super-refractory status epilepticus, ages 2-16 years, were identified. 4/10 patients had immune mediated encephalitis, including Rasmussen encephalitis, anti-N-methyl-d-aspartate receptor encephalitis, and post-infectious mycoplasma encephalitis. Other etiologies included Lennox Gastaut Syndrome, non-ketotic hyperglycinemia, PCDH19 and GABRG2 genetic epilepsy, New Onset Refractory Status Epilepticus, and Febrile Infection-Related Epilepsy Syndrome. 4/10 patients' EEG features suggested focal with status epilepticus, and 6/10 suggested generalized with status epilepticus. Median hospital length was 61days and median ICU length was 27days. The median number of antiepileptic medications prior to diet initiation was 3.0 drugs, and the median after ketogenic diet treatment was 3.5 drugs. Median duration of status epilepticus prior to KD was 18days. 9/10 patients had resolution of super-refractory status epilepticus in a median of 7days after diet initiation. 8/9 patients were weaned off anesthesia within 15days of diet initiation, and within 1day of achieving ketonuria. 1/10 patients experienced side effects on the diet requiring supplementation. Most patients achieved resolution of status epilepticus on KD therapy, suggesting it could be an effective therapy that can be utilized early in the treatment of children with super refractory status epilepticus. Copyright © 2016. Published by Elsevier Ltd.

  8. Early Use of the NMDA Receptor Antagonist Ketamine in Refractory and Superrefractory Status Epilepticus

    Directory of Open Access Journals (Sweden)

    F. A. Zeiler

    2015-01-01

    Full Text Available Refractory status epilepticus (RSE and superrefractory status epilepticus (SRSE pose a difficult clinical challenge. Multiple cerebral receptor and transporter changes occur with prolonged status epilepticus leading to pharmacoresistance patterns unfavorable for conventional antiepileptics. In particular, n-methyl-d-aspartate (NMDA receptor upregulation leads to glutamate mediated excitotoxicity. Targeting these NMDA receptors may provide a novel approach to otherwise refractory seizures. Ketamine has been utilized in RSE. Recent systematic review indicates 56.5% and 63.5% cessation in seizures in adults and pediatrics, respectively. No complications were described. We should consider earlier implementation of ketamine or other NMDA receptor antagonists, for RSE. Prospective study of early implementation of ketamine should shed light on the role of such medications in RSE.

  9. Use of perampanel in one case of super-refractory hypoxic myoclonic status: Case report

    Directory of Open Access Journals (Sweden)

    Estevo Santamarina

    2015-01-01

    Conclusion: This case shows the potential utility of PER as a therapeutic option in super-refractory hypoxic status and even its potential use before other aggressive alternatives considering their greater morbidity.

  10. REE and Trace Element Geochemistry of Yinachang Fe-Cu-REE Deposit, Yunnan Province, China

    Institute of Scientific and Technical Information of China (English)

    杨耀民; 涂光炽; 胡瑞忠

    2004-01-01

    REE and other trace elements in ores, wall rocks, alkaline volcanic rocks and diabase dikes have been determined in the Yinachang Fe-Cu-REE deposit. Comparative studies of REE and trace element geochemical characteristics of these geological bodies indicate that the ores and alkaline volcanic rocks contain abundant REE and Y (65.9-4633)×10-6, with higher abundances of As, Mo, Nb, Co and U than those of the crust. Their chondrite-normalized patterns show a strong enrichment of LREE and a positive Eu anomaly, in contrast to those of the dolomites which are characterized by slight LREE enrichment and moderate negative Eu anomaly. The REE patterns of ores are similar to those of hydrothermal sediment cores in the East Pacific Rise, whereas the REE patterns of dolomites are similar to those of PAAS (Post-Archean Average Shale). In combination with the geological setting of the deposit, the primary ore-forming fluids might have higher REE and volatile elements, and might have been derived from mantle degassing, or the alkaline volcanic magmas. The Yinachang Fe-Cu-REE ore deposit is considered to be of volcanic exhalation-hydrothermal sedimentary origin.

  11. Highly evolved juvenile granites with tetrad REE patterns: the Woduhe and Baerzhe granites from the Great Xing'an Mountains in NE China

    Science.gov (United States)

    Jahn, Bor-ming; Wu, Fuyuan; Capdevila, R.; Martineau, F.; Zhao, Zhenhua; Wang, Yixian

    2001-12-01

    In NE China, voluminous granitoids were emplaced in late Paleozoic and Mesozoic times. We report here Sr-Nd-O isotopic and elemental abundance data for two highly evolved granitic plutons, Woduhe and Baerzhe, from the Great Xing'an Mountains. They show a rather "juvenile" Sr-Nd isotopic signature and a spectacular tetrad effect in their REE distribution patterns as well as non-CHARAC (charge-and-radius-controlled) trace element behavior. The emplacement ages are constrained at 130±4 Ma for the Woduhe and 122±5 Ma for the Baerzhe granites by Rb-Sr and Sm-Nd isotope analyses. Both granites are also characterized by low but imprecise initial 87Sr/ 86Sr ratios of about 0.703. The Nd-Sr isotope data argue for their generation by melting of dominantly juvenile mantle component with subordinate recycled ancient crust. This is largely compatible with the general scenario for much of the Phanerozoic granitoids emplaced in the Central Asian Orogenic Belt. The parental magmas for both the Woduhe and Baerzhe granites have undergone extensive magmatic differentiation, during which intense interaction of the residual melts with aqueous hydrothermal fluids (probably rich in F and Cl) resulted in the non-CHARAC trace element behavior and the tetrad effect of REE distribution. Both the Woduhe and Baerzhe granites show the characteristic trace element patterns of rare-metal granites, but their absolute abundances differ by as much as two orders of magnitude. The oxygen isotope compositions of the two granites have been severely disturbed. Significant 18O depletion in feldspar, but not so much in quartz, suggests that the hydrothermal alteration took place in a temperature condition of 300-500 °C. This subsolidus hydrothermal alteration is decoupled from the late-stage magma-fluid interaction at higher temperatures. Despite the two distinct and intense events of "water-rock" interaction, the Rb-Sr and Sm-Nd geochronological systems seem to have maintained closed, hence, suggesting

  12. Intravenous ketogenic diet therapy for treatment of the acute stage of super-refractory status epilepticus in a pediatric patient.

    Science.gov (United States)

    Lin, Jainn-Jim; Lin, Kuang-Lin; Chan, Oi-Wa; Hsia, Shao-Hsuan; Wang, Huei-Shyong

    2015-04-01

    A ketogenic diet has been used successfully to treat intractable epilepsy. However, the role of early intravenous initiation of ketogenic diet in the acute phase of super-refractory status epilepticus is not well-described. An intravenous ketogenic diet was administered to a boy with super-refractory status epilepticus. At 24 hours after intravenous ketogenic diet, moderate ketosis appeared, and thiamylal was successfully weaned at 70 hours after admission. An intravenous ketogenic regimen led to subsequent ketosis and seizure control in a child with super-refractory status epilepticus. Early induction of ketosis may be a novel strategy to effectively treat super-refractory status epilepticus. Although there are few data regarding the early use of intravenous ketogenic diet in the treatment of super-refractory status epilepticus, it may be considered an alternative option. Copyright © 2015 Elsevier Inc. All rights reserved.

  13. REE Characteristics and Petrogenesis of Amphibolites in the Dabie Complex

    Institute of Scientific and Technical Information of China (English)

    王江海; 游振东; 等

    1994-01-01

    Based on their REE features, stratoid or lenticular amphibolites in the Dabie Complex are di-vided into two types:one is characterized by flat REE distribution patterns and the other by LREE-enrichment. Results of the REE quantitative modeling suggest that the amphibolites were formed from 20% partial melting of garnet lherzolite and 35-56% fractional crystallization of olivine(type TH1) or 14-20% fractional crystallization of olivine and clinopyroxene(type TH2).

  14. Distinct 238U/235U ratios and REE patterns in plutonic and volcanic angrites: Geochronologic implications and evidence for U isotope fractionation during magmatic processes

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    Tissot, François L. H.; Dauphas, Nicolas; Grove, Timothy L.

    2017-09-01

    Angrites are differentiated meteorites that formed between 4 and 11 Myr after Solar System formation, when several short-lived nuclides (e.g., 26Al-26Mg, 53Mn-53Cr, 182Hf-182W) were still alive. As such, angrites are prime anchors to tie the relative chronology inferred from these short-lived radionuclides to the absolute Pb-Pb clock. The discovery of variable U isotopic composition (at the sub-permil level) calls for a revision of Pb-Pb ages calculated using an ;assumed; constant 238U/235U ratio (i.e., Pb-Pb ages published before 2009-2010). In this paper, we report high-precision U isotope measurement for six angrite samples (NWA 4590, NWA 4801, NWA 6291, Angra dos Reis, D'Orbigny, and Sahara 99555) using multi-collector inductively coupled plasma mass-spectrometry and the IRMM-3636 U double-spike. The age corrections range from -0.17 to -1.20 Myr depending on the samples. After correction, concordance between the revised Pb-Pb and Hf-W and Mn-Cr ages of plutonic and quenched angrites is good, and the initial (53Mn/55Mn)0 ratio in the Early Solar System (ESS) is recalculated as being (7 ± 1) × 10-6 at the formation of the Solar System (the error bar incorporates uncertainty in the absolute age of Calcium, Aluminum-rich inclusions - CAIs). An uncertainty remains as to whether the Al-Mg and Pb-Pb systems agree in large part due to uncertainties in the Pb-Pb age of CAIs. A systematic difference is found in the U isotopic compositions of quenched and plutonic angrites of +0.17‰. A difference is also found between the rare earth element (REE) patterns of these two angrite subgroups. The δ238U values are consistent with fractionation during magmatic evolution of the angrite parent melt. Stable U isotope fractionation due to a change in the coordination environment of U during incorporation into pyroxene could be responsible for such a fractionation. In this context, Pb-Pb ages derived from pyroxenes fraction should be corrected using the U isotope composition

  15. Progressive Brain Atrophy in Super-refractory Status Epilepticus.

    Science.gov (United States)

    Hocker, Sara; Nagarajan, Elanagan; Rabinstein, Alejandro A; Hanson, Dennis; Britton, Jeffrey W

    2016-10-01

    Prolonged seizures in super-refractory status epilepticus (SRSE) have been shown to cause neuronal death and reorganization, and visual inspection in individual case studies has demonstrated progressive cortical and subcortical atrophy. At present, magnetic resonance imaging (MRI) studies that evaluate brain atrophy in SRSE are lacking. To document and quantify the development of atrophy over time in SRSE. This retrospective medical record review included all patients with SRSE who were admitted to a tertiary referral campus of the Mayo Clinic Hospital with SRSE from January 1, 2001, to December 31, 2013. Patients with (1) an initial MRI scan performed within 2 weeks of SRSE onset, (2) a second MRI scan within 6 months of SRSE resolution, and (3) a minimum duration of 1 week between MRI scans were included. The ventricular brain ratio (VBR) was measured on T2-weighted fluid-attenuated inversion recovery (FLAIR) images at disease onset and during follow-up. Measurements were performed on axial FLAIR images with section thickness of less than 5 mm. The plane immediately superior to the caudate head was chosen for analysis. The hypothesis that atrophy develops during SRSE despite seizure control (electroencephalogram background suppression with anesthetic drugs) was tested. Data were analyzed from June 1 to December 31, 2015. Change in VBR (ΔVBR) as a percentage of the starting measure. Nineteen patients met the inclusion criteria; these included 10 men (53%) and 9 women (47%) with a median age of 41 (interquartile range [IQR], 25-68) years. Anesthetic agents were required for a median of 13 (IQR, 5-37) days. Initial MRI was performed a median of 2 (IQR, 1-7.5) days from the onset of SRSE, and the second MRI was performed a median of 11 (IQR, 5-15.5) days from the resolution of SRSE, with a median of 40 (IQR, 15-65) days between MRI scans. Median ΔVBR was 23.3% (IQR, 10.5%-70.3%). A significant correlation between the duration of anesthetic agent use and ΔVBR was

  16. Study on REEs as tracers for late permian coal measures in Bijie City, Guizhou Province, China

    Institute of Scientific and Technical Information of China (English)

    WANG Qiang; YANG Ruidong

    2008-01-01

    Analyses of Rare Earth Elements (REEs) in 13 coal samples collected from Late Permian coal measures of Bijie City in western Guizhon Province were conducted using Inductively Coupled Plasma-Mass-Spectrometry (ICP-MS). The results indicated that REEs patterns were not controlled by materials from the sea, whereas the contribution of land plants was about 1%. The major sources of REEs were from terrigenous material as indicated by negative Eu anomaly. There were similar distribution curves of REEs between Bijie's coal and Emeishan basalt. M12 coal seam, which had the highest ∑REE, appeared near the boundary between Longtan Formation and Changxing Formation, which was closely correlated to the eruption of Emeishan basalt. The Emeishan basalt contributed to REEs enrichment of M12. So the sources of REEs were controlled by terrigenous material, and the Emeishan basalt was the predominant source of terrigenous material, which dominated the enrichment and pattern of REEs in Late Permian coal measure from Bijie.

  17. Metal loading levels influence on REE distribution on humic acid: Experimental and Modelling approach

    Science.gov (United States)

    Marsac, R.; Davranche, M.; Gruau, G.; Dia, A.

    2009-04-01

    In natural organic-rich waters, rare earth elements (REE) speciation is mainly controlled by organic colloids such as humic acid (HA). Different series of REE-HA complexation experiments performed at several metal loading (REE/C) displayed two pattern shapes (i) at high metal loading, a middle-REE (MREE) downward concavity, and (ii) at low metal loading, a regular increase from La to Lu (e.g. Sonke and Salters, 2006; Pourret et al., 2007). Both REE patterns might be related to REE binding with different surface sites on HA. To understand REE-HA binding, REE-HA complexation experiments at various metals loading were carried out using ultrafiltration combined with ICP-MS measurements, for the 14 REE simultaneously. The patterns of the apparent coefficients of REE partition between HA and the inorganic solution (log Kd) evolved regularly according to the metal loading. The REE patterns presented a MREE downward concavity at low loading and a regular increase from La to Lu at high loading. The dataset was modelled with Model VI by adjusting two specific parameters, log KMA, the apparent complexation constant of HA low affinity sites and DLK2, the parameter increasing high affinity sites binding strength. Experiments and modelling provided evidence that HA high affinity sites controlled the REE binding with HA at low metal loading. The REE-HA complex could be as multidentate complexes with carboxylic or phenolic sites or potentially with sites constituted of N, P or S as donor atoms. Moreover, these high affinity sites could be different for light and heavy REE, because heavy REE have higher affinity for these sites, in low density, and could saturate them. These new Model VI parameter sets allowed the prediction of the REE-HA pattern shape evolution on a large range of pH and metal loading. According to the metal loading, the evolution of the calculated REE patterns was similar to the various REE pattern observed in natural acidic organic-rich waters (pH10 mg L-1). As

  18. REE Geochemistry of Precambrian Metamorphic Rocks in Wutaishan Region

    Institute of Scientific and Technical Information of China (English)

    吴素珍

    1989-01-01

    The metasedimentary-volcanic series of the Wutai and Hutuo groups experienced regional metamorphism and thus turned into moderate-to low-grade metamorphic rocks.REE abundances and REE distribution patterns in the Shizui and Taihuai Subgroup metasedimentary-volcanic rocks are typical of the Archean,whereas the Gaofan Subgroup and the Hutuo Group show post-Archean REE geochemical char-acteristics.Five types of REE distribution pattern are distinguished:(1)rightward inclined smooth curves with little REE anomaly(Eu/Eu*=0.73-0.95) and heavy REE depletion (e.g.the Late Archean metasedimentary rocks);(2)rightward inclined V-shaped curves with sharp Eu anoma-ly (Eu/Eu*=0.48-0.76) and slightly higher ∑REE (e.g.the post-Archean metasedimentary rocks);(3) rightward inclined steep curves with negative Eu anomaly(Eu/Eu*=0.73-0.76) and the lowest ∑REE (e.g.the post-Archean dolomites);(4)rightward inclined,nearly smooth curves with both positive Eu anomaly and unremarkable positive Eu anomaly(Eu/Eu*=0.95-1.25)(e.g.the meta-basic volcanic rocks);and (5) rightward inclined curves with Eu anomaly(Eu/Eu*=1.09-1.19)and heavy REE depletion(e.g.the meta-acid volcanic rocks).Strata of the two groups are considered to have been formed in an island-arc belt-an instable continental petrogenetic environment.

  19. REE geochemistry of surface sediments in the Chukchi Sea

    Institute of Scientific and Technical Information of China (English)

    陈志华; 高爱国; 刘焱光; 孙海清; 石学法; 杨作升

    2003-01-01

    Analyses of rare earth elements (REEs) in 26 surface sediment samples obtained from the Chukchi Sea were conducted using ICP-MS. In general, REEs are relatively rich in fine-grained sediments and deplete in coarse-grained sediments in the Chukchi Sea although REEs have large concentration spans in different types of sediments. Except that a few samples have weak enrichments of light or heavy REEs,most samples exhibit flat shale-normalized REE pattern, indicating that surface sediments in the Chukchi Sea are composed dominantly of terrigenous components experiencing weak chemical weathering. In terms of REE concentrations and other characteristic parameters, we inferred that sediments on the eastern and western sides of the Chukchi Sea are derived from landmasses of Alaska and Siberia, respectively; the midsouth sediments are possibly related to northward dispersion of the Yukon River materials. The Herald Shoal in the center of the study area is covered with relict sediment, which has large ratios of light-to-heavy REEs (∑Ce/∑Y ratio) and lacks evident negative Ce anomaly; cerium enrichment is possibly related to manganese transfer under oxidizing conditions in early diagenesis.

  20. A Geochemical Study of an REE-rich Carbonatite Dyke at Bayan Obo, Inner Mongolia, Northern China

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    An REE-rich carbonatite dyke was found in Dulahala, close to the Bayan Obo superlarge REE-Nb-Fe mineral deposit in Inner Mongolia, northern China. The REE content in the dyke varies greatly, from 1% up to 20% (wt), which might constitute rich REE ores. Light REEs in the carbonatite are enriched and highly fractionated relative to heavy REEs and there is no Eu anomaly. The REE and trace element distribution patterns of the carbonatite are identical to those of fine-grained dolomite marble which is the host rock of the Bayan Obo REE-Nb-Fe superlarge mineral deposit. This indicates a petrogenetic linkage between the REE-rich carbonatite and the mineralizations in this region.

  1. REE Geochemical Study of the Permian-Triassic Marine Sedimentary Environment in Guizhou Province

    Institute of Scientific and Technical Information of China (English)

    南君亚; 刘丛强; 周德全; 王筑明

    2002-01-01

    This paper deals with the REE geochemical characteristics of Permian-Triassic marine carbonate rocks in Guizhou Province. It is found that there are two broad categories of stratigraphic units in the region studied in accordance with their ∑ REE contents and REE distribution patterns: one is characterized by LREE enrichment and slight Ce depletion, with the REE distribution patterns similar to those of North American shales, and the other features relative HREE enrichment and relatively remarkable Ce depletion, with the REE distribution patterns close to those of pelagic sediments. In terms of their different ∑ REE contents, five types of stratigraphic units can be distinguished. Incorporation of detrital minerals, REE complexing capability, oxidation-reduction conditions of the media are the main factors affecting the REE composition and REE distribution patterns of marine carbonate rocks in the region studied. In the light of REE geochemical characteristics of carbonate rocks, coupled with sedimentary facies analysis, this paper discusses the characteristics of the Permian-Triassic marine sedimentary environment in Guizhou Province and its evolutional rules.

  2. Transportation of REE in the Ductile Shear Zone in Hetai Gold Deposit, Guangdong Province

    Institute of Scientific and Technical Information of China (English)

    杨凤根; 王鹤年; 华仁民

    2003-01-01

    The REE transportation in two sorts of mylonites of ductile shear zone, in Hetai gold deposit, Guangdong province was studied. The results show that there is REE compositional variation regularly in the ductile shear zone. When mica-quartz schist and migmatite are changing into mylonites or ultramylonites, I.e., along with intensifying deformation, the contents of each rare earth element and the total contents of the LREE, HREE and REE increase or decrease regularly, but the REE patterns of the rock are accordant. The isocon diagram of the tectonic rocks before and after deformation shows that the REE compositional variation of the mylonites or ultramylonites are very small, but there is a few REE moving in or out in the rock deformation. The reason of the REE compositional variation is that there are volume change and fluid flow in the rock deformation, and it leads to the LREE relative enrichment and HREE relative loss.

  3. REE Geochemistry of Moderate- and High- Sulfur Coals from North Shanxi, China

    Institute of Scientific and Technical Information of China (English)

    王文峰; 秦勇; 宋党育; 傅雪海

    2003-01-01

    Contents of the rare-earth elements ( REE ) in two coal seams from North Shanxi Province, China, were determined using the instrumental neutron activation method. Based on the REE distribution patterns, and correlation analysis and cluster analysis, the main conclusions were drawn as follows. The REE contents are controlled mainly by the coal-forming environments, but might be affected by acidic solution leaching after peat sedimentation. The REE distribution patterns should be nearly the same in the sublayers of the same coal seam, and the occurrence of abnormal patterns might indicate the geological effect during post-sedimentation.The REE in coals are present mainly in the inorganic phase, and might be derived mainly from terrigenous detrital minerals. Some harmful elements, such as V, P, Mo, Cr, Cu, Mo, Th and Cd, might have cleaning potential during processing and dressing by washing because they are associated with REE.

  4. REE incorporation and behaviour in aquatic turtles as a consequence of environmental exposure and biological processes

    Science.gov (United States)

    Censi, P.; Randazzo, L. A.; D'Angelo, S.; Cuttitta, A.; Saiano, F.

    2012-04-01

    Rare Earth Elements (REE) contents in Emys trinacris have been investigated for the first time in order to recognise effects of the chemistry of the environment on the composition of biological fluids. Representing radionuclides a potential health risk for living organisms in case of incorporation in tissues and being REE geochemical analogues of actinides in hydrosphere, this study was focused on investigation of REE behaviour in whole blood and esoskeleton of selected individuals of Emys trinacris. The choice of this species is related to its amphibian character that allowed us to evidence environmental stress in terms of composition of environmental freshwaters whose REE compositions were investigated and compared with blood samples. Moreover effects induced by different environmental conditions were investigated collecting samples in two sites characterised by absence of an anthropogenic signature (GT site) and subjected to strong anthropogenic pressure in terms of wastewater input (SIC site), respectively. In both sites REE contents in whole blood samples of studied turtles are quite similar even if in GT site the highest REE contents have been recognised. Shale-normalised REE patterns show very similar REE behaviour with light REE (LREE) enrichments with respect to heavier REE (HREE), mainly in samples from anthropized site. If REE concentrations in whole blood are normalised to the composition of environmental waters, calculated REE patterns show upward concave shapes centred on Gd that are more pronounced in samples from GT site because their patterns are more enriched in LREE. The last features observed in blood samples from GT can be related to larger REE contents occurred in environmental water from this site with respect to waters collected in SIC site, suggesting that a relationship occurs between REE contents in environmental and biological fluids. Since MREE depletions were observed in waters experiencing phosphate crystallization, observed REE

  5. Geochemical Characteristics of REE in Jurassic Coal of Yan'an Formation from Dongsheng Coalfield

    Institute of Scientific and Technical Information of China (English)

    赵峰华; 丛志远; 彭苏萍; 唐跃刚; 任德贻

    2002-01-01

    Concentrations of rare earth elements (REE) in Jurassic coal of YanAn Formation from Dongsheng coalfield located in the northeast of Ordos basin were determined by instrumental neutron activation analysis (INAA). Curves of distrib ution pattern of REE were drawn, and many geochemical parameters were calculated . The result shows that 1) The contents of REE in Jurassic coal with low ash an d sulfur are lower than those of Carboniferous and Permian coal from the Basin of North China; 2) Inside the Dongsheng coalfield, coal from the north has high er contents of REE than that form the south because the north is near the area of source rock which is the main supplier of REE, while the south is far away from the area of source rocks; 3) Although Jurassic coal in Dongsheng is the low-ash coal with less than 10%, the contents of REE are still proportional to ash yie ld of ash and SiO2 contents. 4) Although the Jurassic coal in Dongsheng were deposited in oxidative continental environment of river-lake, Eu depletion of RE E I n coal commonly exists, and positive abnormity of Ce dose not exist. This reflec ts the REE distribution pattern of REE in source rock of continental area; and 5) Compared with other rocks, coal shows extremely complexity of distribution pa ttern of REE, which is the result of continuous alteration and redistribution of matter in coal occurred in open basin system.

  6. Biological Function of REE in Plants & Microbes

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Rare earth elements (REE) and their compounds are widely applied in agronomic and medical fields for many years. The bioinorganic chemical research of REE during the past few years indicates that REE play important roles in the promotion of photosynthetic rate as well as root absorption, regulation of hormone and nitrogen metabolism, and suppression of microbes, etc. The metallic or non-metallic targets of key biomolecule in various physiological processes can be chosen by REE for the chelation or replacement, which enables REE to regulate the biological functions or behaviors of those biomolecule and consequently leads to significant embodiment of biological function of REE in plants and microbes.Overdose of REE, however, shows an inhibitory effect on living organisms. Therefore, this paper proposes two suggestions that will be available in the extension of full use of REE's biological function. One is to obey the dose law of REE and control REE concentrations within a safe range. The other is to further test the bioaccumulation and long-period influence of REE on organisms.

  7. REE bound DNA in natural plant

    Institute of Scientific and Technical Information of China (English)

    王玉琦; 江平; 郭繁清; 张智勇; 孙景信; 许雷; 曹国印

    1999-01-01

    The binding of rare earth elements (REEs) with nucleic acids in the leaves of fern Dicranopteris dichotoma (DD) has been studied by molecular activation analysis (MAA). The REEs bound DNA (REE-DNA) was obtained from the leaves of DD. The CTAB-based procedure was modified for extraction of total DNA. The purity of DNA was examined by UV spectroscopy. The DNA obtained was separated and determined by agarose gel electrophoresis further. Meanwhile, the contents of eight rare earth elements (La, Ce, Nd, Sm, Eu,Tb, Yb and Lu) in REE-DNA were detected by instrumental neutron activation analysis (INAA). The results showed that REE-DNA with higher purity could be extracted from plant using this method. It was also found that REEs were bound firmly with DNA in the leaves of DD. The molecular weight (MW) of REE-DNA band was about 22 kb in agarose gel electrophoresis.

  8. Refractory and super-refractory status epilepticus in adults: a 9-year cohort study.

    Science.gov (United States)

    Delaj, L; Novy, J; Ryvlin, P; Marchi, N A; Rossetti, A O

    2017-01-01

    While status epilepticus (SE) persisting after two antiseizure agents is called refractory (RSE), super-refractory status epilepticus (SRSE) defines SE continuing after general anaesthesia. Its prevalence and related clinical profiles have received limited attention, and most studies were restricted to intensive care facilities. We therefore aimed at describing RSE and SRSE frequencies and identifying associated clinical variables. Between 2006 and 2015, consecutive adult SE episodes were prospectively recorded in a registry. Occurrence of RSE and SRSE and their relationship to clinical variables of interest, including outcome, were analysed. Of 804 SE episodes, 268 (33.3%) were RSE and 33 (4%) SRSE. Coma induction for SE treatment occurred in 79 (9.8%) episodes. Severe consciousness impairment (OR 1.67; 95% CI 1.24-2.46; P = 0.001), increasing age (OR 1.01, 95% CI 1.01-1.02), and lack of remote symptomatic SE aetiology (OR 0.48; 95% CI 0.32-0.72) were independently associated with RSE, while severe consciousness impairment (OR 4.26; 95% CI 1.44-12.60) and younger age (OR 0.96; 95% CI 0.95-0.99) correlated with SRSE; however, most SRSE episodes were not predicted by these variables. Mortality was 15.5% overall, higher in RSE (24.5%) and SRSE (37.9%) than in non-refractory SE (9.8%) (P < 0.001). Super-refractory status epilepticus appears clearly less prevalent in this cohort than previously reported, probably as it is not restricted to intensive care unit. SRSE emerges in younger patients with marked consciousness impairment, pointing to the underlying severe clinical background, but these variables do not predict most SRSE developments. There is currently a knowledge gap for prediction of SRSE occurrence that needs to be filled. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  9. Incorporation of REE into leucophanite

    DEFF Research Database (Denmark)

    Mortensen, Henrik Friis; Balic Zunic, Tonci; Williams, C.T.;

    2007-01-01

    The crystal structures of nine, and the chemical compositions of ten, natural samples of leucophanite, ideally NaCaBeSi2O6F, were investigated. The analysed samples display a large compositional variation with trace-element abundances >50,000 ppm, primarily due to rare earth elements (REE....... The crystal structure of the nine analysed samples could all be refined in space group P212121. We found no evidence for a reduction of symmetry with increased trace-element concentration. Various twin combinations were observed and these seem related to crystallization conditions rather than structural...

  10. Using in situ REE analysis to study the origin and diagenesis of dolomite of Lower Paleozoic, Tarim Basin

    Institute of Scientific and Technical Information of China (English)

    WANG XiaoLin; JIN ZhiJun; HU WenXuan; ZHANG JunTao; QIAN YiXiong; ZHU JingQuan; LI Qing

    2009-01-01

    In situ REE concentrations of various dolomites from Tarim Basin were obtained by LA-ICP-MS analysis, and the data were normalized to standard seawater (Seawater Normalized=SWN). Most of the samples have a ΣREE range of less than 20 ppm. All samples show similar REE distributions with heavy REE depletion, and positive Ce anomaly, which indicates that they have the same dolomitization fluids (seawater). According to the origin and diagenetic process of dolomite, two types of dolomite are de-termined and described as follows: 1) syndepositional dolomite, with the highest REE concentrations (more than 20 ppm), the cores of which are more enriched in REE compared with their cortexes, indicating that they underwent the dolomitization of calcareous sediments by hypersaline and subsequent diagenesis decreased the REE content of the cortex because of the low REE concentration of the diagenetic fluids; 2) diagenetic dolomite, which can be subdivided into four groups. (1) burial dolomite which has higher REE concentrations than limestone, but lower than syndepositional dolomite. This shows that pore fluids with high salinity dolomitized the pre-existing limestone; (2) void filling dolomite which has the similar REE patterns with the matrix dolomite. In addition, the Eu anomaly is not obvious, suggesting that the dolomitization fluids originated from the diagenetic fluids; (3) recrystallized dolomite, whose REE concentration was obviously decreased, indicating that the REE concentration was decreased during the recrystallization processes; and (4) hydrothermal altered void-filling dolomite, which has the lowest REE concentration, but obvious positive Eu anomaly, reflecting its hydrothermal activity related origin. Thus, the diverse REE signatures, which were recorded in different dolomites, retain the information of their formation conditions and subsequent diagenetic processes. In situ REE analysis of dolomite is an effective probe into the origin and diagenetic process of

  11. REE Geochemical Characteristics of Apatite,Sphene and Zircon from Alkaline Rocks

    Institute of Scientific and Technical Information of China (English)

    周玲棣; 王杨传

    1989-01-01

    The accessory minerals apatite and sphene are the main carriers of REE in alkaline rocks.Their chondrite-normalized REE patterns decline sharply to the right as those of the host rocks,In the patterns an obvious negative Eu anomaly and a positive Ce anomaly can be seen in apatite and sphene,respectively.Zircon from alkaline rocks is different in REE pattern,I,e,. a nearly symmetric"V"-shaped pattern with a maximum negative Eu anomaly.Compared with the equivalents from granites,apatite,sphene and zircon from alkaline rocks are all characterized by higher (La/Yb)N ratio and less Eu depletion,As to the relative contents of REE in minerals,apatite,sphene and zircon are enriched in LREE,MREE and HREE respectively,depending on their crystallochemical properties.

  12. REE/trace element characteristics of sandstone-type uranium deposits in the Ordos Basin

    Institute of Scientific and Technical Information of China (English)

    LING Mingxing; YANG Xiaoyong; SUN Wei; MIAO Jianyu; LIU Chiyang

    2006-01-01

    The major elements, trace elements and REEs were analyzed on the samples collected from the sandstone-type uranium deposits in the Ordos Basin to constrain the mechanism of uranium enrichment. The total REE amount ranges from 36.7 to 701.8 μg/g and the REE distribution patterns of the sandstone-type uranium samples are characterized by LREE enrichment and high REE depletion. The results also indicated a high Y abundance and Eu anomalies between 0.77-1.81. High-precision ICP-MS results showed that U abundances are within the range of 0.73-150 μg/g, showing some strong correlation between U enrichment and related elements such as Ti, V, Zr, Mo, and Au. In addition, Th abundance is correlated with ΣREE.

  13. REE Compositions of Lower Ordovician Dolomites in Central and North Tarim Basin, NW China: A Potential REE Proxy for Ancient Seawater

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xuefeng; HU Wenxuan; JIN Zhijun; ZHANG Juntao; QIAN Yixiong; ZHU Jingquan; ZHU Dongya; WANG Xiaolin; XIE Xiaomin

    2008-01-01

    Rare earth dement compositions of Lower Ordovician dolomites in the Central and Northern Tarim Basin are studied. Most dolomite samples are more or less contaminated by clay minerals. Their rare earth element compositions have been consequently changed, showing both seawater-like and non-seawater-like features. The clay contamination should be disposed before the REE data are used. Through ICP-MS and ICP-AES analyses, the REE features are well documented. The clay contamination is quantitatively determined by microscopic investigation, trace elements and REE contents. The dolomites, at least in the Tarim Basin, are thought to be pure when their total LREE contents are less than 3x10-6. Through comparison, the pure dolomites show similarities in REE patterns but differences in REE contents with co-existing pure limestone, which indicates that dolomitization may slightly change the REE compositions. Nevertheless, whatever the change is, the pure dolomites may act as a potential REE proxy for Ordovician seawater, which would be significant for ancient massive dolomite strata that lack limestone.

  14. Using in situ REE analysis to study the origin and diagenesis of dolomite of Lower Paleozoic,Tarim Basin

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    In situ REE concentrations of various dolomites from Tarim Basin were obtained by LA-ICP-MS analysis,and the data were normalized to standard seawater(Seawater Normalized=SWN).Most of the samples have a ΣREE range of less than 20 ppm.All samples show similar REESWN distributions with heavy REE depletion,and positive Ce anomaly,which indicates that they have the same dolomitization fluids(seawater).According to the origin and diagenetic process of dolomite,two types of dolomite are determined and described as follows:1) syndepositional dolomite,with the highest REE concentrations(more than 20 ppm),the cores of which are more enriched in REE compared with their cortexes,indicating that they underwent the dolomitization of calcareous sediments by hypersaline and subsequent diagenesis decreased the REE content of the cortex because of the low REE concentration of the diagenetic fluids;2) diagenetic dolomite,which can be subdivided into four groups.(1) burial dolomite which has higher REE concentrations than limestone,but lower than syndepositional dolomite.This shows that pore fluids with high salinity dolomitized the pre-existing limestone;(2) void filling dolomite which has the similar REE patterns with the matrix dolomite.In addition,the Eu anomaly is not obvious,suggesting that the dolomitization fluids originated from the diagenetic fluids;(3) recrystallized dolomite,whose REE concentration was obviously decreased,indicating that the REE concentration was decreased during the recrystallization processes;and(4) hydrothermal altered void-filling dolomite,which has the lowest REE concentration,but obvious positive Eu anomaly,reflecting its hydrothermal activity related origin.Thus,the diverse REE signatures,which were recorded in different dolomites,retain the information of their formation conditions and subsequent diagenetic processes.In situ REE analysis of dolomite is an effective probe into the origin and diagenetic process of dolomite.

  15. Petrologic and REE Geochemical Characters of Burnt Rocks

    Institute of Scientific and Technical Information of China (English)

    HUANG Lei; LIU Chiyang; YANG Lei; ZHAO Junfeng; FANG Jianjun

    2008-01-01

    The study of burnt rocks is beneficial to the discussion on the tectonic movement,paleoclimate and paleogeography that coal seams are subjected to after they were formed. In order to obtain the basic data on the features of the burnt rocks, a systematic study of petrology and REE geochemistry on burnt rocks in Shenmu, Northern Shaanxi Province has been done, using the methods of SEM, EDS, susceptibility measurements and ICP-MS. The burnt rocks are divided into two series in the section: the melted rocks and the baked rocks. SEM and EDS analyses reveal that all the minerals show burnt and melted traces, and there are no clay minerals except iliite found in the burnt rocks. Susceptibility measurements reveal that the burnt rocks have abnormally high susceptibility values,whereas a geochemical analysis shows that the REE distribution pattern of burnt rocks is similar to that of sedimentary rocks (initial rocks). In the longitudinal section, with increasing degree of burning (from baked rocks to melted rocks), the ΣREE gradually decreases, and the total REE of melted rocks is obviously lower than that of baked rocks. Besides, the melted rocks show apparent negative Ce anomalies, while the baked rocks show no anomaly of Ce, and sometimes even show positive anomalies.

  16. Zircon U-Pb ages and Sr-Nd-Hf isotopes of the highly fractionated granite with tetrad REE patterns in the Shamai tungsten deposit in eastern Inner Mongolia, China: Implications for the timing of mineralization and ore genesis

    Science.gov (United States)

    Jiang, Si-Hong; Bagas, Leon; Hu, Peng; Han, Ning; Chen, Chun-Liang; Liu, Yuan; Kang, Huan

    2016-09-01

    The Shamai tungsten deposit is located in the eastern part of the Central Asian Orogenic Belt (CAOB). Tungsten mineralization is closely related to the emplacement of fine- to medium-grained biotite monzogranite (G1) and porphyritic biotite monzogranite (G2) in the Shamai Granite. NW-trending joints and faults host orebodies in the Shamai Granite and Devonian hornfels. The mineralization is characterized by a basal veinlet zone progressing upwards to a thick vein zone followed by a mixed zone, a veinlet zone, and a thread vein zone at the top. The ore-related alteration typically consists of muscovite, greisen, and hornfels. In order to constrain the timing of the Shamai mineralization and discuss the ore genesis, muscovite Ar-Ar, molybdenite Re-Os, and zircon U-Pb geochronological, geochemical, and Sr-Nd-Hf isotopic studies were completed on the deposit. The U-Pb zircon dating yielded weighted mean ages of 153 ± 1 Ma for G1 and 146 ± 1 Ma for G2. Muscovite from a wolframite-bearing quartz vein yielded an Ar-Ar plateau age of 140 ± 1 Ma, whereas two molybdenite samples yielded identical Re-Os model ages of 137 ± 2 Ma. These two ages are younger than the two monzogranites, suggesting a prolonged magmatic-hydrothermal interaction during tungsten mineralization. Major and trace element geochemistry shows that both G1 and G2 are characterized by high SiO2 and K2O contents, high A/CNK values (1.08-1.40), a spectacular tetrad effect in their REE distribution patterns, and non-CHARAC (charge-and-radius-controlled) trace element behavior. This suggests that both G1 and G2 are highly differentiated peraluminous rocks with strong hydrothermal interaction. The Nd-Hf isotope data for the Shamai Granite (εNd(t) between - 1.9 and + 7.4, ɛHf(t) from 5.2 to 12.8) are largely compatible with the general scenario for much of the Phanerozoic granite emplaced in the CAOB. It is here suggested that the Shamai Granite originated from partial melting of a juvenile lower crust with

  17. Rare earth element geochemistry of Late Devonian reefal carbonates, Canning Basin, Western Australia: confirmation of a seawater REE proxy in ancient limestones

    Science.gov (United States)

    Nothdurft, Luke D.; Webb, Gregory E.; Kamber, Balz S.

    2004-01-01

    Rare earth element and yttrium (REE+Y) concentrations were determined in 49 Late Devonian reefal carbonates from the Lennard Shelf, Canning Basin, Western Australia. Shale-normalized (SN) REE+Y patterns of the Late Devonian samples display features consistent with the geochemistry of well-oxygenated, shallow seawater. A variety of different ancient limestone components, including microbialites, some skeletal carbonates (stromatoporoids), and cements, record seawater-like REE+Y signatures. Contamination associated with phosphate, Fe-oxides and shale was tested quantitatively, and can be discounted as the source of the REE+Y patterns. Co-occurring carbonate components that presumably precipitated from the same seawater have different relative REE concentrations, but consistent REE+Y patterns. Clean Devonian early marine cements ( n = 3) display REE+Y signatures most like that of modern open ocean seawater and the highest Y/Ho ratios (e.g., 59) and greatest light REE (LREE) depletion (average Nd SN/Yb SN = 0.413, SD = 0.076). However, synsedimentary cements have the lowest REE concentrations (e.g., 405 ppb). Non-contaminated Devonian microbialite samples containing a mixture of the calcimicrobe Renalcis and micritic thrombolite aggregates in early marine cement ( n = 11) have the highest relative REE concentrations of tested carbonates (average total REE = 11.3 ppm). Stromatoporoid skeletons, unlike modern corals, algae and molluscs, also contain well-developed, seawater-like REE patterns. Samples from an estuarine fringing reef have very different REE+Y patterns with LREE enrichment (Nd SN/Yb SN > 1), possibly reflecting inclusion of estuarine colloidal material that contained preferentially scavenged LREE from a nearby riverine input source. Hence, Devonian limestones provide a proxy for marine REE geochemistry and allow the differentiation of co-occurring water masses on the ancient Lennard Shelf. Although appropriate partition coefficients for quantification of

  18. Ion-adsorption REEs in regolith of the Liberty Hill pluton, South Carolina, USA: An effect of hydrothermal alteration

    Science.gov (United States)

    Bern, Carleton R.; Yesavage, Tiffany; Foley, Nora K.

    2017-01-01

    Ion-adsorbed rare earth element (REE) deposits supply the majority of world heavy REE production and substantial light REE production, but relatively little is known of their occurrence outside Southeast Asia. We examined the distribution and forms of REEs on a North American pluton located in the highly weathered and slowly eroding South Carolina Piedmont. The Hercynian Liberty Hill pluton experiences a modern climate that includes ~ 1500 mm annual rainfall and a mean annual temperature of 17 °C. The pluton is medium- to coarse-grained biotite-amphibole granite with minor biotite granite facies. REE-bearing phases are diverse and include monazite, zircon, titanite, allanite, apatite and bastnäsite. Weathered profiles were sampled up to 7 m-deep across the ~ 400 km2 pluton. In one profile, ion-adsorbed REEs plus yttrium (REE + Y) ranged up to 581 mg/kg and accounted for up to 77% of total REE + Y in saprolite. In other profiles, ion-adsorbed REE + Y ranged 12–194 mg/kg and only accounted for 3–37% of totals. The profile most enriched in ion-adsorbed REEs was located along the mapped boundary of two granite facies and contained trioctahedral smectite in the saprolite, evidence suggestive of hydrothermal alteration of biotite at that location. Post-emplacement deuteric alteration can generate easily weathered REE phases, particularly fluorocarbonates. In the case of Liberty Hill, hydrothermal alteration may have converted less soluble to more soluble REE minerals. Additionally, regolith P content was inversely correlated with the fraction ion-adsorbed REEs, and weathering related secondary REE-phosphates were found in some regolith profiles. Both patterns illustrate how low P content aids in the accumulation of ion-adsorbed REEs. The localized occurrence at Liberty Hill sheds light on conditions and processes that generate ion-adsorbed REEs.

  19. Regulation of sialidase production in Clostridium perfringens by the orphan sensor histidine kinase ReeS.

    Directory of Open Access Journals (Sweden)

    Thomas J Hiscox

    Full Text Available Clostridium perfringens is ubiquitous in nature and is often found as a commensal of the human and animal gastrointestinal tract. It is the primary etiological agent of clostridial myonecrosis, or gas gangrene, a serious infection that results in extensive tissue necrosis due to the action of one or more potent extracellular toxins. α-toxin and perfringolysin O are the major extracellular toxins involved in the pathogenesis of gas gangrene, but histotoxic strains of C. perfringens, such as strain 13, also produce many degradative enzymes such as collagenases, hyaluronidases, sialidases and the cysteine protease, α-clostripain. The production of many of these toxins is regulated either directly or indirectly by the global VirSR two-component signal transduction system. By isolating a chromosomal mutant and carrying out microarray analysis we have identified an orphan sensor histidine kinase, which we have named ReeS (regulator of extracellular enzymes sensor. Expression of the sialidase genes nanI and nanJ was down-regulated in a reeS mutant. Since complementation with the wild-type reeS gene restored nanI and nanJ expression to wild-type levels, as shown by quantitative reverse transcription-PCR and sialidase assays we concluded that ReeS positively regulates the expression of these sialidase genes. However, mutation of the reeS gene had no significant effect on virulence in the mouse myonecrosis model. Sialidase production in C. perfringens has been previously shown to be regulated by both the VirSR system and RevR. In this report, we have analyzed a previously unknown sensor histidine kinase, ReeS, and have shown that it also is involved in controlling the expression of sialidase genes, adding further complexity to the regulatory network that controls sialidase production in C. perfringens.

  20. REE Geochemical Characteristics of Tungsten Minerals as a Discriminant Indicator of Genetic Types of Ore Deposits

    Institute of Scientific and Technical Information of China (English)

    张玉学; 刘文茂; 等

    1990-01-01

    Tungsten minerals (scheelite and wolframite)from two genetic types of granitoids show significant dif-ferences in REE distribution,probably due to different material sources and origins.Tungsten miner-als in granite porphyry of the crust-mantle source are relatively high in ∑REE(1884ppm on average).∑ Ce is rich relative to ∑Y and ∑Ce/∑Y is relatively high(>1).The chondrite-normalized REE distribution patterns are characterized by a group of rightward-inclined curves.Tungsten minerals in quartz veins intruding the granites of crust origin have lower ∑REE (335 ppm on average).∑Y is rich relative to ∑Ce and ∑Ce/∑Y is relatively low(<1).The chondrite-normalized REE distribution patterns are characterized by a group of leftward-inclined curves.So the REE distribution patterns can be used to discriminate the sources of rock-and ore-forming materials and the genetic types of W deposits so as to provide clues to ore prospecting.

  1. Contrasting REE Signatures on Manganese Ores of Iron Ore Group in North Orissa, India

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The distribution pattern of Rare Earth Elements (REE) in three categories of manganese ores viz.stratiform, stratabound-replacement, and detrital of Precambrian Iron Ore Group from north Orissa, India was reported.These categories of Mn-ore differed in their major and trace chemistry and exhibited contrasting REE signature.The stratiform ores were relatively enriched in REE content (697 μg·g-1) and their normalized pattern showed both positive Ce and Eu anomalies, whereas the stratabound-replacement types were comparatively depleted in REE content (211 μg·g-1) and showed negative Ce and flat Eu signatures.The detrital categories showed mixed REE pattern.The data plotted in different discrimination diagrams revealed a mixed volcaniclastic and chemogenic source of material for stratiform categories, and LREE (Light Rare Earth Elements) and HREE (Heavy Rare Earth Elements) are contributed by such sources, respectively.In contrast, the stratabound ore bodies were developed during the remobilization of stratiform ores, and associated Mn-containing rocks under supergene condition followed by the redeposition of circulating mineralized colloidal solutions in structurally favorable zones.During this process, some of the constituents were found only in very low concentration within stratabound ores, and this is attributed to their poor leachability/mobility.The detrital ores did not exhibit any significant characteristic in respect of REE as their development was via a complex combination of processes involving weathering, fragmentation, recementation, and burial under soil cover.

  2. Mega-dose phenobarbital therapy for super-refractory status epilepticus.

    Science.gov (United States)

    Byun, Jung-Ick; Chu, Kon; Sunwoo, Jun-Sang; Moon, Jangsup; Kim, Tae-Joon; Lim, Jung-Ah; Jun, Jin-Sun; Lee, Han Sang; Lee, Woo-Jin; Lee, Doo Young; Jeon, Daejong; Lee, Soon-Tae; Jung, Keun-Hwa; Jung, Ki-Young; Lee, Sang Kun

    2015-12-01

    To evaluate the efficacy and safety of mega-dose phenobarbital (MDPB; enteral or parenteral phenobarbital >10 mg/kg/day) for treating super-refractory status epilepticus (SRSE; continuous or recurrent status epilepticus for ≥24 hours after the onset of continuous anaesthetic treatment) in adult patients. Adult patients with SRSE who were treated with MDPB in our institution from March 2005 to September 2014 were reviewed. We collected data on basic demographics, clinical features, functional status, anticonvulsant treatment, and possible adverse events. SRSE outcome was divided into six categories: successful therapy, initial failure, breakthrough seizures, withdrawal seizures, intolerable side effects, and death during treatment. Ten adult patients with SRSE received MDPB. Median age at seizure onset was 38 years (range: 18-59), and half were male. All patients had no history of seizures and had symptoms suggestive of viral encephalitis. Median duration of status epilepticus was 17.5 days (range: 6-60) and anaesthetics were used for a median of 14.0 days (range: 2-54) before MDPB. Successful control of SRSE was achieved in half of the patients, however, only one of ten patients was able to fully recover at discharge. Median duration of the MDPB was 45.5 days and the maximum serum phenobarbital level reached a median of 151.5 μg/ml. Patients with successful MDPB therapy had normal brain imaging (80% vs. 0%; p=0.048) and better functional outcome at discharge and after three months of follow-up. Infection was the most critical complication, along with cardiorespiratory depression. MDPB is a therapeutic option for control of SRSE when other choices are exhausted.

  3. The treatment of super-refractory status epilepticus: a critical review of available therapies and a clinical treatment protocol.

    Science.gov (United States)

    Shorvon, Simon; Ferlisi, Monica

    2011-10-01

    Super-refractory status epilepticus is defined as status epilepticus that continues or recurs 24 h or more after the onset of anaesthetic therapy, including those cases where status epilepticus recurs on the reduction or withdrawal of anaesthesia. It is an uncommon but important clinical problem with high mortality and morbidity rates. This article reviews the treatment approaches. There are no controlled or randomized studies, and so therapy has to be based on clinical reports and opinion. The published world literature on the following treatments was critically evaluated: anaesthetic agents, anti-epileptic drugs, magnesium infusion, pyridoxine, steroids and immunotherapy, ketogenic diet, hypothermia, emergency resective neurosurgery and multiple subpial transection, transcranial magnetic stimulation, vagal nerve stimulation, deep brain stimulation, electroconvulsive therapy, drainage of the cerebrospinal fluid and other older drug therapies. The importance of treating the identifying cause is stressed. A protocol and flowchart for managing super-refractory status epilepticus is suggested. In view of the small number of published reports, there is an urgent need for the establishment of a database of outcomes of individual therapies.

  4. The outcome of therapies in refractory and super-refractory convulsive status epilepticus and recommendations for therapy.

    Science.gov (United States)

    Ferlisi, Monica; Shorvon, Simon

    2012-08-01

    In a previous paper, we reviewed the range of therapies available for the treatment of super-refractory status epilepticus. Here we report a review of the outcome of therapies in refractory and super-refractory status epilepticus. Patients (n = 1168) are reported who had therapy with: thiopental, pentobarbital, midazolam, propofol, ketamine, inhalational anaesthetics (isoflurane, desflurane), antiepileptic drugs (topiramate, lacosamide, pregabalin, levetiracetam), hypothermia, magnesium, pyridoxine, immunotherapy, ketogenic diet, emergency neurosurgery, electroconvulsive therapy, cerebrospinal fluid drainage, vagal nerve stimulation and deep brain stimulation. The outcome parameters reported include control of status epilepticus, relapse on withdrawal, breakthrough seizures and mortality. Where reported (596 cases), the long-term outcome was found to be death (35%), severe neurological deficit (13%), mild neurological deficit (13%), undefined deficit (4%) and recovery to baseline (35%). The quality of reported outcome data is generally poor and the number of cases reported for all non-anaesthetic therapies is low. Outcome assessment is complicated by changes in co-medication, delay in response and publication bias. Given these deficits, only broad recommendations can be made regarding optimal therapy. An approach to therapy, divided into first-line, second-line and third-line therapy, is suggested on the basis of this outcome evaluation. The importance of treatments directed at the cause of the status epilepticus, and of supportive ITU care is also emphasized.

  5. REE Geochemical Characteristics of Volcanic Rocks in Zhejiang and Jiangxi Provinces and Their Gological Significance

    Institute of Scientific and Technical Information of China (English)

    王剑锋

    1991-01-01

    Based on the data of 64 samples ,the REE geochemical characteristics of volcanic rocks in northern Zhejiang and eastern Jiangxi provinces are discussed in this paper.The REE distribution patterns in acid and intermediate-acid volcanic rocks in these areas display some similarities,as indicated by rightward-inclined V-shaped curves with negative Eu anomalies,which are parallel to earch other.In addi-tion,their REE parameters(ΣREE,ΣLREE/ΣHREE,δEu,Ce/Yb,La/Sm,La/Yb,etc)also va-ry over a narrow range with small deviations.HREE are particularly concentrated in the volcanic rocks as-sociated with uranium mineralization.The initial 87Sr/86Sr ratio in the volcanic rocks is about 0.7056-0.7139.All these features in conjunction with strontium isotopic data indicate that the rock-forming materials come from the sialic crust.The REE distribution patterns and REE geochemical parameters of the volcanic rocks ,as well as La/Sm-La and Ce/Yb-Eu/Yb diagrams may be applied to the sources of rock-forming and ore-forming materials.

  6. REE concentration processes in ion adsorption deposits: Evidence from Madagascar and China.

    Science.gov (United States)

    Smith, Martin; Estrade, Guillaume; Marquis, Eva; Goodenough, Kathryn; Nasun, Peter; Cheng, Xu; Kynicky, Jindrich

    2017-04-01

    Lateritic clay deposits, where the rare earth elements (REE) occur adsorbed to clay mineral surfaces, are the world's dominant supply of heavy REE (Gd-Lu). These deposits are currently only mined in China where there is a reported heavy REE enrichment, but other deposits are currently under exploration in Brazil, the Philippines and Madagascar. Concentration of REE within IADs has been proposed to be a dominantly supergene process, where easily degradable REE-minerals (e.g. REE-fluorcarbonates) break down and release REE that are then adsorbed to clay minerals resulting in HREE enrichment. Here we present data from the Ambohimirahavavy Complex, Madagascar, and compare them to data from mineralised profiles in China, with the aim of further constraining the formation and REE enrichment processes in ion adsorption deposits. Bulk rock total REE contents from Madagascar vary from 400-5000ppm, with the HREE varying from 10 to 20% of the TREE. Ammonium Sulphate leaches (designed to remove clay-adsorbed REE) of laterite show leachable TREE from 130-500ppm, with no preferential HREE adsorption. Within the sequential extraction procedure the reducible fraction (hydroxylammonium chloride leach) showed the highest REE, but this is largely attributable to Ce4+ in oxide layers. Analysis of laterite profiles show that the REE distribution is heterogeneous, with control from both bedrock heterogeneity, and the hydrological variation between pedolith and saprolith. Similar patterns are seen in Chinese profiles from Jiangxi province. X-ray diffraction shows the clay fraction in all sites is dominated by kaolinite and halloysite. These data are consistent with experimental data which show that kaolinite is only HREE selective in high ionic strength solutions (Coppin et al., 2002), and suggest that HREE enrichment in lateritic deposits may be a function of exceptional bed rock conditions. Petrographic investigation of the Zhaibei granite, immediately underlying HREE enriched

  7. REE Geochemistry of Euphrates River, Turkey

    Directory of Open Access Journals (Sweden)

    Leyla Kalender

    2016-01-01

    Full Text Available The study area is located on the Euphrates River at 38°41°32.48′′N–38°14′24.10′′N latitude and 39°56′4.59′′E–39°8°13.41′′E longitude. The Euphrates is the longest river in Western Asia. The lithological units observed from the bottom to the top are Permo-Triassic Keban Metamorphites, Late Cretaceous Kömürhan Ophiolites, Upper Cretaceous Elazığ Magmatic Complex, Middle Eocene Maden Complex and Kırkgeçit Formation, Upper Pliocene and Lower Eocene Seske Formation and Upper Miocene, Pliocene Karabakır and Çaybağı Formations, Palu Formation, and Holocene Euphrates River sediments. The geochemical studies show that 87Sr/86Sr and 143Nd/144Nd isotopic compositions in the Euphrates River bank sediments are 0.7053, 0.7048, and 0.7057 and 0.512654, 0.512836, and 0.512775, respectively. These values indicate mixing of both carbonate-rich shallow marine sediment and felsic-mafic rocks from Elazığ Magmatic Complex into the stream sediments. The positive εNd (0 values (0.35, 3.9, and 2.7 are higher downstream in the studied sediments due to weathering of the mafic volcanic rocks. The chondrite, NAS, and UCC normalized patterns show that the REE compositions of the Euphrates River sediments are higher than chondrite composition but close to NAS and UCC. The river sediments in the tectonic zone and the weathered granodioritic rocks of the Elazığ Magmatic complex affect upstream water compositions.

  8. Homology and cohomology of Rees semigroup algebras

    DEFF Research Database (Denmark)

    Grønbæk, Niels; Gourdeau, Frédéric; White, Michael C.

    2011-01-01

    Let S by a Rees semigroup, and let 1¹(S) be its convolution semigroup algebra. Using Morita equivalence we show that bounded Hochschild homology and cohomology of l¹(S) is isomorphic to those of the underlying discrete group algebra.......Let S by a Rees semigroup, and let 1¹(S) be its convolution semigroup algebra. Using Morita equivalence we show that bounded Hochschild homology and cohomology of l¹(S) is isomorphic to those of the underlying discrete group algebra....

  9. In situ ion microprobe U-Pb dating and REE abundances of a carboniferous conodont

    Science.gov (United States)

    Sano, Yuji; Terada, Kentaro

    We report here in situ ion microprobe U-Pb dating of a conodont micro-fossil using an ion microprobe method. Thirteen spots on the single fragment of the Carboniferous conodont (size: approximately 800 µm × 100 µm) yield a 238U/206Pb isochron age of 323±36 Ma and a Tera-Wasserburg concordia intercept age of 332±44 Ma in a three-dimensional 238U/206Pb-207Pb/206 Pb-204Pb/206Pb diagram. These ages are consistent with the depositional and early diagenetic ages of the fossil in its host Mississippian sedimentary sequence within experimental error. The success of the method depends on the chemical fractionation of U from Pb within a hundred-µm length scale and the consequent variations in Pb isotopic compositions due to radioactive decay. Shale-normalized rare earth element (REE) abundances of two spots on the same sample show flat patterns from light REE to middle REE and decreases from middle REE to heavy REE with negative anomalies of both Ce and Eu. The REE characteristics are significantly different from those of Devonian conodonts reported by other workers, suggesting discrepant redox states and/or formation environments.

  10. Double sodium REE niobates with the fersmite structure

    Energy Technology Data Exchange (ETDEWEB)

    Fedorov, N.F.; Mel' nikova, O.V.; Pivovarova, A.P.; Starkova, N.V.; Bazhenova, O.A.

    1987-09-01

    The authors study double sodium REE niobates with the fersmite structure. The diffraction-pattern indexing for the compounds CaNb/sub 2/O/sub 6/ and Na/sub 0.5/Ln/sub 0.5/Nb/sub 2/O/sub 6/ is presented, as well as the crystallochemical features of those compounds. For some of the compounds in the series studied, the authors determined the unit-cell parameters on the assumption that they are orthorhombic, by analogy to CaNb/sub 2/O/sub 6/.

  11. The Rees Algebra for Certain Monomial Curves

    CERN Document Server

    Mukhopadhyay, Debasish

    2010-01-01

    In this article, we find the equations defining the Rees algebra for certain Monomial Curves explicitly and use them to prove that the blowup scheme is not smooth. This proves a conjecture of Francia in affirmative, which says that a dimension one prime in a regular local ring is a complete intersection if it has a smooth blowup.

  12. REE Abundaces in Megacrysts and Host Basalts:REE Behavior of Magma at High Pressures

    Institute of Scientific and Technical Information of China (English)

    肖森宏

    1991-01-01

    Based on REE abundances in megacrysts and host basalts and their equilibrium conditions,it has proved that megacrysts may have been produced from the magma derived from the host rocks or of more basic composition.The REE ratios of megacrysts to host rocks may be taken as partition coefficients when both are equilibrium with each other.The crystal fractionation of megacrysts has caused the evolution of REE in the magma.It is obvious that some host basalts are the product of magma evolution after crystal fractionation.According to REE abundances in the host rocks and the partition coefficients between crystal and liquid,the history of crystal fractionation of magma can be traced.

  13. REE in the Great Whale River estuary, northwest Quebec

    Science.gov (United States)

    Goldstein, Steven J.; Jacobsen, Stein B.

    1988-05-01

    A report on REE concentrations within the estuary of the Great Whale River in northwest Quebec and in Hudson Bay is given, showing concentrations which are less than those predicted by conservative mixing of seawater and river water, indicating removal of REE from solution. REE removal is rapid, occurring primarily at salinities less than 2 percent and ranges from about 70 percent for light REE to no more than 40 percent for heavy REE. At low salinity, Fe removal is essentially complete. The shape of Fe and REE vs. salinity profiles is not consistent with a simple model of destabilization and coagulation of Fe and REE-bearing colloidal material. A linear relationship between the activity of free ion REE(3+) and pH is consistent with a simple ion-exchange model for REE removal. Surface and subsurface samples of Hudson Bay seawater show high REE and La/Yb concentrations relative to average seawater, with the subsurface sample having a Nd concentration of 100 pmol/kg and an epsilon(Nd) of -29.3; characteristics consistent with river inputs of Hudson Bay. This indicates that rivers draining the Canadian Shield are a major source of nonradiogenic Nd and REE to the Atlantic Ocean.

  14. REE Characteristics of the Kalatongke Cu-Ni Deposit, Xinjiang, China

    Institute of Scientific and Technical Information of China (English)

    WANG Yuwang; WANG Jingbin; WANG Lijuan; WANG Yong; TU Caineng

    2004-01-01

    On the basis of the study on the REE geochemistry of the ore minerals and host rocks of the Kalatongke Cu-Ni deposit, Xinjiang, it is indicated that the major ore minerals, sulfides, were sourced from the host mafic-ultramafic magma.Characterized by low REE content of sulfide, such a Cu-Ni sulfide deposit occurring in the orogen is obviously different from that on the margin of the craton. Because the mafic-ultramafic rocks from the Cu-Ni sulfide deposit occurring in the orogen is water-rich and the REEs of some sulfides show a particular "multiple-bending" pattern, which suggests coexistence of multiple liquid phases (fluid and melt), the sulfide melt possibly contains a great deal of hydrothermal fluids and increasingly developed gases and liquid-rich ore-forming fluids after the main metallogenic epoch (magmatic segregation stage).

  15. Ion microprobe U-Pb dating and REE abundance of biogenic apatite

    Science.gov (United States)

    Sano, Y.; Terada, K.; Ueki, S.

    2001-12-01

    If the direct U-Pb dating of a fossil itself is possible, the method could have great impact on stratigraphic studies in establishing the absolute chronology of sedimentary sequences. Micro fossil ?conodont? are candidates for this purpose since they consist of apatite (Ca2(PO5)3 (F,Cl,OH)), which would uptake U, Th and Pb after sedimentation no longer than a few million years and is supposed to remain closed to U and Pb under relatively low effective closure temperature. We report here results of direct ion microprobe U-Th-Pb dating of two conodonts; Trichognathus from Kinderhookian stage of Mississippian sedimentary sequence from Illinois Basin region in North America and Panderodus from a Llandoverian sedimentary sequence on Langkawi Island, northern Malaysia. Secondary purpose of the study is to indicate in situ analysis of all REE on the same spots of U-Pb measurements. Samples were cast into epoxy resin discs with a few grains of standard apatite, PRAP, derived from an alkaline rock of Prairie Lake circular complex in the Canadian Shield and polished until they were exposed through their mid-sections. U, Th and REE abundances, and Pb isotopic compositions were measured by using SHRIMP installed at Hiroshima University. Thirteen spots on Trichognathus yield a 238U/206Pb isochron age of 323+/-36 Ma, which is consistent with the depositional and early diagenetic ages. Fifteen spots on Panderodus give 232Th/208Pb isochron age of 429+/-50 Ma, which is again comparable to an early Silurian. Shale-normalized REE of Trichognathus shows a broadly flat pattern from light to middle REE and a decrease from middle to heavy REE with negative anomalies of Ce and Eu. In contrast Panderodus indicates a concave-shape pattern with middle REE enrichment. These characteristics are probably due to a different formation environment as suggested by other workers.

  16. Temporal variations in the export of REE in boreal catchments of varying character and size

    Science.gov (United States)

    Köhler, S.; Lidman, F.; Mörth, M.; Björkvald, L.; Laudon, H.

    2009-04-01

    Organic matter and iron colloids have a large impact on the mobilisation of trivalent elements such as aluminium (Al), rare earth elements (REE) and actinides. Recent results of the relative importance of these colloids are diverging though (POURRET et al., 2007); STEINMANN and STILLE, 2008) and there is a general lack of information of the importance of flow pathways and landscape type on the relative importance of the various colloidal fractions that mobilizes REE from the catchment soils. In this study we present the data of water chemical analysis of a series of catchments with varying size and character but all within the boreal zone. Two speciation techniques and two column separation methods involving ion exchange were used to quantify the causes for the temporal variation of the dissolved amounts of trivalent ions in these water courses. Our study indicates that REE export is controlled mostly by landscape type while changes in the acid-base character of organic matter are of minor importance. Changes in flow pathways in a riparian zone in one of the studied areas in a forested site may be used to decipher the effect of chemical versus physical processes for the mobilisation of REE and aluminium and open up the possibility for a quantitative modelling of the varying sources of REE. Iron and aluminium are mobilized together with organic matter in varying amounts in different landscape types and this affects the REE export from the various landscape elements. While the amount of strongly bound aluminium mobilized from the catchments usually correlate positively with any of the REE this is not the case for strongly bound iron. Fractionation patterns of REE are discussed and the observed binding of REE to organic matter was modelled using the speciation program WHAM VI (TIPPING, 1998). Pourret O., Davranche M., Gruau G., and Dia A. (2007) Organic complexation of rare earth elements in natural waters: Evaluating model calculations from ultrafiltration data

  17. Rare earth elements (REEs in vertebrate microremains from the upper Pridoli Ohesaare beds of Saaremaa Island, Estonia: geochemical clues to palaeoenvironment c

    Directory of Open Access Journals (Sweden)

    Živilė Žigaitė

    2015-02-01

    Full Text Available Rare earth element (REE compositions of Nostolepis sp. scales, spines, plates and tesserae from Ohesaare bone beds were measured by in situ microsampling using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS. The obtained REE concentrations, normalized to Post-Archean Australian Shale concentrations, were evaluated using basic geochemical calculations and quantifications. The REE compositions were nearly identical across all the morphotypes and histologies of Nostolepis microremains, showing flat REE patterns with slight depletion in heavy REEs. There was no visible enrichment in middle REEs, indicating good geochemical preservation of bioapatite and absence of any pronounced fractionated REE incorporation during later stages of diagenesis. The shale-normalized (La/YbSN and (La/SmSN REE ratio compilations indicated adsorption as the dominating REE uptake mechanism across all datapoints. The absence of well-defined Ce anomaly suggested oxic palaeoseawater conditions, which agrees with the existing interpretations of the Ohesaare sequence as high-energy shoal and regressive open ocean sedimentary environments.

  18. Tinjauan Kemungkinan Sebaran Unsur Tanah Jarang (REE di Lingkungan Panas Bumi

    Directory of Open Access Journals (Sweden)

    Danny Zulkifli Herman

    2014-06-01

    Full Text Available http://dx.doi.org/10.17014/ijog.vol4no1.20091Geothermal areas occur mainly in an environment of volcanic/magmatic arc where magma chambers play a role as heat sources. The environment is situated within the convergent plate boundaries. A variety of igneous rocks is associated with this environment ranging from basalt (gabbro to rhyolite (granite but andesite is normally the most abundant igneous rock. The most obvious geothermal indications are exhibited by some surface manifestations comprising hot water seepage, fumaroles, hot spring, geyser, and hydrotermal alteration zones which are being evidences of an active hydrothermal system beneath the surface as a part of volcanism. Despite being a causal factor for alteration of country rocks, most hydrothermal fluids enable to change distribution pattern and content of rare earth elements (REE for instance Ce, Eu, La, Lu, Sm, Nd, and Y particularly during a reaction process. This may have a connection with development of element mobility rates, whilst the characteristics of REE pattern within hydrothermal fluid would have a high variable due to dependency of their original magma source. Considering the important role of hydrothermal fluid in REE mobility development, it is inspired to review the possible relationship of active hydrothermal system and potency of REE distribution pattern in areas of geothermal manifestation.  

  19. Tinjauan Kemungkinan Sebaran Unsur Tanah Jarang (REE di Lingkungan Panas Bumi

    Directory of Open Access Journals (Sweden)

    Danny Zulkifli Herman

    2014-06-01

    Full Text Available http://dx.doi.org/10.17014/ijog.vol4no1.20091Geothermal areas occur mainly in an environment of volcanic/magmatic arc where magma chambers play a role as heat sources. The environment is situated within the convergent plate boundaries. A variety of igneous rocks is associated with this environment ranging from basalt (gabbro to rhyolite (granite but andesite is normally the most abundant igneous rock. The most obvious geothermal indications are exhibited by some surface manifestations comprising hot water seepage, fumaroles, hot spring, geyser, and hydrotermal alteration zones which are being evidences of an active hydrothermal system beneath the surface as a part of volcanism. Despite being a causal factor for alteration of country rocks, most hydrothermal fluids enable to change distribution pattern and content of rare earth elements (REE for instance Ce, Eu, La, Lu, Sm, Nd, and Y particularly during a reaction process. This may have a connection with development of element mobility rates, whilst the characteristics of REE pattern within hydrothermal fluid would have a high variable due to dependency of their original magma source. Considering the important role of hydrothermal fluid in REE mobility development, it is inspired to review the possible relationship of active hydrothermal system and potency of REE distribution pattern in areas of geothermal manifestation.  

  20. REE Zonation in Garnet: new insights from combined Thermodynamic and Diffusion Modelling

    Science.gov (United States)

    Witte, C.; Konrad-Schmolke, M.

    2013-12-01

    Compositional variation in garnet provides an excellent record of element transport within their host rocks, as it precisely reflects the interplay between thermodynamically-controlled nutrient demand and kinetically-constrained element availability during growth. Element availability is controlled by (1) the thermodynamically controlled element distribution among co-existing phases and (2) by matrix transport properties. Our task is to distinguish between factors controlling the availability of major- and trace-elements and to quantify their diffusion length scales but this is hindered by the fact that the interplay of different rate-limiting factors on garnet growth and composition are not fully understood. These processes comprise: (1) fractional garnet crystallisation, which continuously changes the effective, i.e. reacting, bulk rock chemistry (EBC), which in turn influences garnet proportion, growth rate and composition; (2) kinetically-controlled element availability, such that grain boundary diffusion in the host rock's interconnecting transport matrix (ITM) or surface processes in reacting phases cannot keep pace with the material required for garnet nucleation and growth in homogeneous thermodynamic equilibrium with the coexisting phase assemblage and (3) reaction-controlled trace element availability in the host rock, which is often reflected in discontinuous trace element zoning patterns in garnet. A 1D diffusion and reaction model was developed to investigate REE distribution patterns in garnet. It combines PERPLEX thermodynamic forward modelling for a bulk rock composition along a P-T-path with control of diffusion rates in the matrix fluid which acts as a transport medium in the intergranular space. Initial REE distribution is controlled by standard distribution coefficients. Reactant phases are the source of REE and product minerals fractionate REE from the transport medium. Thus the uptake of REE in garnet is regulated by: (1) thermodynamically

  1. Elimination and nonlinear equations of Rees algebra

    CERN Document Server

    Busé, Laurent; Simis, Aron

    2009-01-01

    A new approach is established to computing the image of a rational map, whereby the use of approximation complexes is complemented with a detailed analysis of the torsion of the symmetric algebra in certain degrees. In the case the map is everywhere defined this analysis provides free resolutions of graded parts of the Rees algebra of the base ideal in degrees where it does not coincide with the corresponding symmetric algebra. A surprising fact is that the torsion in those degrees only contributes to the first free module in the resolution of the symmetric algebra modulo torsion. An additional point is that this contribution -- which of course corresponds to non linear equations of the Rees algebra -- can be described in these degrees in terms of non Koszul syzygies via certain upgrading maps in the vein of the ones introduced earlier by J. Herzog, the third named author and W. Vasconcelos. As a measure of the reach of this torsion analysis we could say that, in the case of a general everywhere defined map, ...

  2. Genesis of iron-apatite ores in Posht-e-Badam Block (Central Iran) using REE geochemistry

    Science.gov (United States)

    Mokhtari, Mir Ali Asghar; Zadeh, Ghader Hossein; Emami, Mohamad Hashem

    2013-06-01

    Rare earth elements in apatites of different ore types show characteristic patterns which are related to different modes of formation of the ores. Most of the apatite-bearing iron ores are associated with alkaline magmas with LREE/HREE fractionation varying from moderate to steep. Iron-apatite deposits in Posht-e-Badam Block (Central Iran) have a high concentration of REE (more than 1000 ppm up to 2.5%), and show a strong LREE/HREE ratio with a pronounced negative Eu anomaly. This REE pattern is typical of magmatic apatite and quiet distinct from sedimentary apatites (phosphorites) which have a low REE contents and Ce negative anomalies. On the other hand, they are comparable to the REE patterns of apatites in Kiruna-type iron ores in different parts of the world. The REE patterns of apatites, iron-apatite ores and iron ores are similar and only have different REE contents. This similarity indicates a genetic relation for these rocks. Most of the iron-apatite deposits in Central Iran have similar REE patterns too, which in turn show a genetic relation for all of these deposits. This similarity indicates a similar origin and processes in their genesis. There are some small intrusions around some of the iron-apatite deposits that are petrographically identified as syenite and gabbro. These intrusions also have REE patterns similar to that of iron-apatite ores. This demonstrates a genetic relation between these intrusions and iron-apatite ores. The REE patterns of apatites in different deposits of Posht-e-Badam Block iron-apatite ores show an affinity to alkaline to sub-alkaline magmas and rifting environment. The alkaline host rocks of Central Iran iron-apatite ores are clearly related to an extensional setting where rifting was important (SSE-NNW fault lines). A probable source for this large scale ore forming processes is relatively low partial melting of mantle rocks. The ores have originated by magmatic differentiation as a late phase in the volcanic cycle

  3. Genesis of iron-apatite ores in Posht-e-Badam Block (central Iran) using REE geochemistry

    Indian Academy of Sciences (India)

    Mir Ali Asghar Mokhtari; Ghader Hossein Zadeh; Mohamad Hashem Emami

    2013-06-01

    Rare earth elements in apatites of different ore types show characteristic patterns which are related to different modes of formation of the ores. Most of the apatite-bearing iron ores are associated with alkaline magmas with LREE/HREE fractionation varying from moderate to steep. Iron-apatite deposits in Posht-e-Badam Block (Central Iran) have a high concentration of REE (more than 1000 ppm up to 2.5%), and show a strong LREE/HREE ratio with a pronounced negative Eu anomaly. This REE pattern is typical of magmatic apatite and quiet distinct from sedimentary apatites (phosphorites) which have a low REE contents and Ce negative anomalies. On the other hand, they are comparable to the REE patterns of apatites in Kiruna-type iron ores in different parts of the world. The REE patterns of apatites, iron-apatite ores and iron ores are similar and only have different REE contents. This similarity indicates a genetic relation for these rocks. Most of the iron-apatite deposits in Central Iran have similar REE patterns too, which in turn show a genetic relation for all of these deposits. This similarity indicates a similar origin and processes in their genesis. There are some small intrusions around some of the iron-apatite deposits that are petrographically identified as syenite and gabbro. These intrusions also have REE patterns similar to that of iron-apatite ores. This demonstrates a genetic relation between these intrusions and iron-apatite ores. The REE patterns of apatites in different deposits of Posht-e-Badam Block iron-apatite ores show an affinity to alkaline to sub-alkaline magmas and rifting environment. The alkaline host rocks of Central Iran iron-apatite ores are clearly related to an extensional setting where rifting was important (SSE–NNW fault lines). A probable source for this large scale ore forming processes is relatively low partial melting of mantle rocks. The ores have originated by magmatic differentiation as a late phase in the volcanic cycle

  4. Genesis of ion-adsorption type REE ores in Thailand

    Science.gov (United States)

    Sanematsu, K.; Yoshiaki, K.; Watanabe, Y.

    2012-04-01

    Ion-adsorption type REE deposits, which have been economically mined only in southern China, are predominant supply sources for HREE in the world. The ore bodies consist of weathered granites called ion-adsorption ores. The majority of REE (>50 %) are electrostatically adsorbed onto weathering products in the ores and they can be extracted by ion exchange using an electrolyte solution (e.g., ammonium sulfate solution). Recently the occurrences of ion-adsorption ores have been reported in Indochina, SE Asia. In this study, we discuss geochemical and mineralogical characteristics of parent granites and weathered granites in Thailand in order to reveal the genesis of ion-adsorption ores. Permo-Triassic and Cretaceous-Paleogene granite plutons are distributed from northern Thailand to western Indonesia through eastern Myanmar and Peninsular Malaysia. They are mostly ilmenite-series calcalkaline biotite or hornblende-biotite granites. REE contents of the granites range from 60 to 600 ppm and they are relatively high in Peninsula Thailand. REE-bearing minerals consist mainly of apatite, zircon, allanite, titanite, monazite and xenotime. Some I-type granites contain REE fluorocarbonate (probably synchysite-(Ce)) in cavities and cracks in feldspars and it is the dominant source of REE for ion-adsorption ores because the fluorocarbonate is easily soluble during weathering. In contrast, insoluble monazite and xenotime are not preferable for ion-adsorption ores although they are common ore minerals of placer REE deposits. Weathered granites show REE contents ranging from 60 to 1100 ppm in Thailand because REE are relatively immobile compared with mobile elements (e.g., Na, K, Ca). In the weathered granites, REE are contained in residual minerals and secondary minerals and are adsorbed onto the surface of weathering products. A weathering profile of granite with ion-adsorption type mineralization can be divided into upper and lower parts based on REE enrichment and Ce

  5. Rare earth elements (REE) as natural and applied tracers in the catchment area of Gessental valley, former uranium mining area of Eastern Thuringia, Germany

    Science.gov (United States)

    Buechel, G.; Merten, D.; Geletneky, J. W.; Kothe, E.

    2003-04-01

    Between 1947 and 1990 about 113.000 t of uranium were excavated at the former uranium mining site of Ronneburg (Eastern Thuringia, Germany). The legacy consists of more than 200 million m^3 of metasedimentary rocks rich in organic matter, sulfides and heavy metals originally deposited in mining heaps at the surface. The metasedimentary rocks formed under anoxic conditions about a 400 Mio. years ago are now exposed to oxic conditions. The oxidation of markasite and pyrite results in the formation of H_2SO_4. The formation of acid mine drainage (AMD) leads to high concentrations of uranium, rare earth elements (REE) and other heavy metals in surface water, seepage water and groundwater. This mobilization is due to alteration enhanced by high microbial activity and low pH. The tolerance mechanisms towards heavy metal pollution of soil substrate and surface/groundwater has allowed the selection of microbes which have, e.g. specific transporter genes and which are associated to plants in symbiotic interactions like mycorrhiza. In order to follow the processes linking alteration of metasedimentary rocks to biological systems the use of tracers is needed. One group of such tracers occuring in high concentrations in the water phase at the Ronneburg mining site are the REE (La-Lu) which are featured by very similar chemical behaviour. They show smooth but continuous variations of their chemical behaviour as a function of atomic number. For seepage water of the waste rock dump Nordhalde - sampled over a period of two years - the shale normalized REE patterns show enrichment of heavy REE and only minor variations, although the concentration differs. At sampling points in the surface water and in groundwater rather similar REE patterns were observed. Thus, REE can be used as tracers to identify diffuse inflow of REE-rich acid mine drainage of the dumps into the creek and the sediments. The absolute concentrations of REE in the creek and in ground water are up to 1000 times

  6. Palaeoenvironmental signatures revealed from rare earth element (REE compositions of vertebrate microremains of the Vesiku Bone Bed (Homerian, Wenlock, Saaremaa Island, Estonia

    Directory of Open Access Journals (Sweden)

    Alexandre Fadel

    2015-02-01

    Full Text Available Rare earth elements (REEs have been analysed from fossil vertebrate microremains (thelodont scales from the Vesiku Bone Bed, Saaremaa, Estonia, using in situ microsampling by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS. Well-preserved scales of three species of the genus Thelodus (T. carinatus, T. laevis and Thelodus sp. show very uniform REE patterns with slightly lower overall REE concentrations in enameloid than in dentine, with enrichment in middle REEs, depletion in heavy REEs and pronounced negative europium anomaly, but no cerium anomaly. The results of this study suggest a similar diagenetic history and possibly contemporaneous habitats for all three Thelodus species, as well as possible suboxic to anoxic conditions of the bottom and pore waters during the formation of the Vesiku Bone Bed.

  7. Quantitatively distinguishing sediments from the Yangtze River and the Yellow River using δEu_N-ΣREEs plot

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Sediment samples were collected from the lower channel of the Yangtze River and the Yellow River and the contents of rare earth elements (REEs) were measured. In addition, some historical REEs data were collected from published literatures. Based on the δEuN-ΣREEs plot, a clear boundary was found be-tween the sediments from the two rivers. The boundary can be described as an orthogonal polynomial equation by ordinary linear regression with sediments from the Yangtze River located above the curve and sediments from the Yellow River located below the curve. To validate this method, the REEs con-tents of sediments collected from the estuaries of the Yangtze River and the Yellow River were meas-ured. In addition, the REEs data of sediment Core 255 from the Yangtze River and Core YA01 from the Yellow River were collected. Results show that the samples from the Yangtze River estuary and Core 255 almost are above the curve and most samples from the Yellow River estuary and Core YA01 are below the curve in the δEuN-ΣREEs plot. The plot and the regression equation can be used to distin-guish sediments from the Yangtze River and the Yellow River intuitively and quantitatively, and to trace the sediment provenance of the eastern seas of China. The difference between the sediments from two rivers in the δEuN-ΣREEs plot is caused by different mineral compositions and regional climate patterns of the source areas. The relationship between δEuN and ΣREEs is changed little during the transport from the source area to the river, and from river to the sea. Thus the original information on mineral compositions and climate of the source area was preserved.

  8. Quantitatively distinguishing sediments from the Yangtze River and the Yellow River using δEuN-ΣREEs plot

    Institute of Scientific and Technical Information of China (English)

    JIANG FuQing; ZHOU XiaoJing; LI AnChun; LI TieGang

    2009-01-01

    Sediment samples were collected from the lower channel of the Yangtze River and the Yellow River and the contents of rare earth elements (REEs) were measured. In addition, some historical REEs data were collected from published literatures. Based on the δEuN-ΣREEs plot, a clear boundary was found be-tween the sediments from the two rivers. The boundary can be described as an orthogonal polynomial equation by ordinary linear regression with sediments from the Yangtze River located above the curve and sediments from the Yellow River located below the curve. To validate this method, the REEs con-tents of sediments collected from the estuaries of the Yangtze River and the Yellow River were meas-ured. In addition, the REEs data of sediment Core 255 from the Yangtze River and Core YA01 from the Yellow River were collected. Results show that the samples from the Yangtze River estuary and Core 255 almost are above the curve and most samples from the Yellow River estuary and Core YA01 are below the curve in the δEuN-ΣREEs plot. The plot and the regression equation can be used to distin-guish sediments from the Yangtze River and the Yellow River intuitively and quantitatively, and to trace the sediment provenance of the eastern seas of China. The difference between the sediments from two rivers in the δEuN-ΣREEs plot is caused by different mineral compositions and regional climate patterns of the source areas. The relationship between δEuN and ΣREEs is changed little during the transport from the source area to the river, and from river to the sea. Thus the original information on mineral compositions and climate of the source area was preserved.

  9. Controls of interactions between iron hydroxide colloid and water on REE fractionations in surface waters: Experimen-tal study on pH-controlling mechanism

    Institute of Scientific and Technical Information of China (English)

    刘丛强; 吴佳红; 于文辉

    2002-01-01

    The influence of pH on the partitioning behavior of REE at the water/particulate interface has been studied experimentally. At the beginning of colloid formation the adsorption of REE on iron hydroxide colloids is dominant, followed by REE desorption. Finally adsorption and desorption tend to reach equilibration. The capability of iron hydroxide colloids to adsorb the HREE is greater than that to adsorb the LREE. With increasing pH, LREE/HREE fractionations will take place between iron hydroxide colloids and water, leading to the reduction of their partition coefficient ratio (DLREE/DHREE). The DREE distribution patterns show Y anomalies (DY/DHo <1), with obvious REE tetrad effects appearing under low pH conditions. Experimental results have shown that there do exist REE tetrad effects in nature. In addition to pH, the chemical type of surface water and ion intensity are also the important factors controlling REE tetrad effects and leading to fractionations between particulate-adsorbed REE and dissolved REE.

  10. Application of REE geochemical signatures for Mesozoic sediment provenance to the Gettysburg Basin, Pennsylvania

    Science.gov (United States)

    Blake, Johanna M.; Peters, Stephen C.; Johannesson, Karen H.

    2017-03-01

    Rift basins adjacent to accreted terranes provide accommodation space for sediments eroded from these terranes. Despite similar depositional environments and geologic age, rocks of the Triassic Gettysburg Basin have approximately half the arsenic concentrations of the adjacent Newark Basin. Quartz-feldspar-lithics (QFL) diagrams and rare earth element (REE) geochemical signatures can inform sediment provenance. Here we investigate REE geochemical signatures of the sedimentary rocks in the Triassic Gettysburg rift basin, with the goal of distinguishing the main sources of siliciclastic sediment among the Appalachian foreland in the rift footwall from Piedmont arc and Iapetan continental margin rocks exposed in the hanging wall and ultimately understanding the geochemical cycling of arsenic to the Gettysburg Basin. Shale-normalized REE spider diagrams and Mann-Whitney tests on trace element ratios suggest that the Gettysburg Basin samples show patterns that most closely resemble those of the Iapetus Continental Slope Rise Iapetus Rift Volcanic, and Accretionary Complex deposits. Mann-Whitney Rank Sum analysis suggest that the Iapetus Continental Slope Rise terrane is the main source of sediments to the basin, which confirms results from prior QFL analysis and shows the utility of REE fingerprinting in provenance analysis. The main sources of sediment have smaller minimum and maximum arsenic concentrations than other terranes and the Newark Basin sediments, additionally suggesting the source of arsenic to the Gettysburg Basin is based upon specific terranes.

  11. Costs, length of stay, and mortality of super-refractory status epilepticus: A population-based study from Germany.

    Science.gov (United States)

    Strzelczyk, Adam; Ansorge, Sonja; Hapfelmeier, Jana; Bonthapally, Vijayveer; Erder, M Haim; Rosenow, Felix

    2017-09-01

    Super-refractory status epilepticus (SRSE) is a severe condition in which a patient in status epilepticus (SE) for ≥24 h does not respond to first-, second-, or third-line therapy. The economic impact of SRSE treatment remains unclear. A health insurance research database was used for a population-based estimation of SRSE-associated inpatient costs, length of stay, and mortality in Germany. An algorithm using International Classification of Diseases, 10th Edition coding and treatment parameters identified and classified patients in a German statutory health insurance database covering admissions from 2008 to 2013 as having refractory SE (RSE) or SRSE. Admissions data in our study refer to these classifications. Associated patient data included costs, procedures, and demographics. The algorithm identified 2,585 (all type) SE admissions, classified as 1,655 nonrefractory SE (64%), 592 (22.9%) RSE, and 338 (13.1%) SRSE, producing database incidence rates of 15.0 in 100,000, 5.2 in 100,000, and 3.0 in 100,000 per year, respectively. Median cost per admission was €4,063 for nonrefractory SE, €4,581 (p RSE, and €32,706 (p RSE, and up to 37 days in SRSE. Discharge mortality increased from 9.6% in nonrefractory SE to 15.0% (p RSE and 39.9% (p < 0.001) in SRSE. This study evaluated the hospital treatment costs associated with admissions classified by the algorithm as SRSE in Germany. SRSE represented 13% of all SE admissions, but resulted in 56% of all SE-related costs. The lack of approved treatments and limited number of evidence-based treatment guidelines highlight the need for further evaluations of the SRSE burden of illness and the potential for further optimization of treatments for SRSE. Wiley Periodicals, Inc. © 2017 International League Against Epilepsy.

  12. REE and (э)Nd of clay fractions in sediments from the eastern Pacific Ocean: Evidence for clay sources

    Institute of Scientific and Technical Information of China (English)

    LIU Jihua; SHI Xuefa; CHEN Lirong; HUANG Yongyang; WANG Yinxi; CUI Yingchun; BU Wenrui

    2005-01-01

    Clay fractions in the non-calcareous surface sediments from the eastern Pacific were analyzed for clay minerals, REE and 143Nd/144Nd. Montmorillonite/illite ratio (M/I ratio), total REE contents ((REE), LREE/HREE ratio and cerium anomaly (бCe) may effectively indicate the genesis of clay minerals. Clay fractions with M/I ratio >1, бCe (0.85, (REE (400 μg/g, LREE/HREE ratio (4, and REE patterns similar to those of pelagic sediments are terrigenous and autogenetic mixed clay fractions and contain more autogenetic montmorillonite. Clay fractions with M/I ratio <1, бCe=0.86 to 1.5, ΣREE=200 to 350 μg/g, LREE/HREE ratio (6 and REE distribution patterns similar to that of China loess are identified as terrigenous clay fraction. The 143Nd/144Nd ratios or (э)Nd values of clay fractions inherit the features of terrigenous sources of clay minerals. Clay fractions are divided into 4 types according to (э)Nd values. Terrigenous clay minerals of type I with the (э)Nd values of -8 to -6 originate mainly from North American fluvial deposits. Those of type II with the (э)Nd values of -9 to -7 are mainly from the East Asia and North American fluvial deposits. Those of type III with (э)Nd values of -6 to -3 could come from the central and eastern Pacific volcanic islands. Those of type IV with (э)Nd values of -13 to -12 may be from East Asia eolian. The terrigenous and autogenetic mixed clay fractions show patchy distributions, indicating that there are volcanic or hot-spot activities in the eastern Pacific plate, while the terrigenous clay fractions cover a large part of the study area, proving that the terrigenous clay minerals are dominant in the eastern Pacific.

  13. Rare earth element (REE) geochemistry of phosphorites of the Sonrai area of Paleoproterozoic Bijawar basin, Uttar Pradesh, India

    Institute of Scientific and Technical Information of China (English)

    K. F. Khan; Shamim A. Dar; Saif A. Khan

    2012-01-01

    The rare earth element (REE) data from the Paleoproterozoic Bijawar basin,Sonrai phosphorites were used to interpret the depositional conditions of the phosphorites.The post archean Australian shales (PAAS) normalized REE patterns of the Sonrai phosphorites were characterized by negative Ce and positive Eu anomalies.Middle rare earth elements (MREE)-ennchment was a characteristic feature.Phosphorites showing the diagenetic effects on the REE patterns were limited.The observed Eu anomaly was indicative of an anoxic (or sulphate reducing) diagenetic environment of phosphate formation.Mixing of sea water and upwelling during the Paleoproterozoic was responsible for the recording of positive Eu and negative Ce anomalies in the Sonrai phosphorites.

  14. Al-26, Pu-244, Ti-50, REE, and trace element abundances in hibonite grains from CM and CV meteorites

    Science.gov (United States)

    Fahey, A. J.; Mckeegan, K. D.; Zinner, E.; Goswami, J. N.

    1987-01-01

    Hibonites from the CM meteorites Murchison, Murray, and Cold Bokkeveld, and hibonites and Ti-rich pyroxene from the CV chondrite Allende are studied. Electron microprobe measurements of major element concentrations and track and ion probe measurements of Mg and Ti isotopic ratios, rare earth elements (REEs), and trace element abundances are analyzed. Correlations between isotopic anomalies in Ti, Al-26, Pu-244, and Mg-26(asterisk) are examined. Ti isotopic anomalies are compared with REE and trace element abundance patterns. Reasons for the lack of Al-26 in the hibonites are investigated and discussed. It is observed that there is no correlation between the Ti isotopic compositions, and the presence of Mg-26(asterisk), Pu-244, and REE and trace element patterns in individual hibonite samples. The data reveal that hibonites are not interstellar dust grains but formed on a short time scale and in localized regions of the early solar system.

  15. Major, trace and REE geochemistry of recent sediments from lower Catumbela River (Angola)

    Science.gov (United States)

    Vinha, Manuela; Silva, M. G.; Cabral Pinto, Marina M. S.; Carvalho, Paula Cristina S.

    2016-03-01

    The mineralogy, texture, major, trace and rare earth elements, from recent sediment samples collected in the lower Catumbela River, were analysed in this study to characterize and discuss the factors controlling its geochemistry and provide data that can be used as tracers of Catumbela River inputs to the Angolan continental shelf. The sediments are mainly sands and silty-sands, but sandy-silt also occurs and the mineralogy is composed of quartz, feldspar, phyllosilicates, magnetite, ilmenite and also carbonates when the river crosses limestones and marls in the downstream sector. The hydraulic sorting originates magnetite-ilmenite and REE-enriched minerals placers. The mineralogy of the sediments is controlled by the source rocks and the degree of chemical weathering is lower than erosion. The texture is mainly controlled by location. There is enrichment in all the analysed trace elements in the fine grained, clay minerals and Fe-oxy-hydroxides rich sediments, compared to the coarse grained and quartz plus feldspar rich ones. The coarse grained sediments (without the placers) are impoverished in ΣREE when compared with UCC and NASC compositions, while the fine grained sediments have ΣREE contents similar to UCC and NASC. The placers have ΣREE contents up to 959.59 mg/kg. The source composition is the dominant factor controlling the REE geochemistry of the analysed sediments as there is no difference in the (La/Yb)N, (La/Sm)N and (Gd/Yb)N ratios in coarse and fine grained sediments. The sorting of magnetite, ilmenite, zircon, throrite, thorianite, rutile and titanite explain the HREE/LREE enriched patterns of the coarse grained sediments.

  16. Hf Isotope Composition and REE Pattern of Zircons from Early Precambrian Metamorphic Rocks in the Daqing Mountains, Inner Mongolia%内蒙古大青山地区早前寒武纪变质岩的锆石Hf同位素组成和稀土模式

    Institute of Scientific and Technical Information of China (English)

    董春艳; 刘敦一; 万渝生; 徐仲元; 王伟; 颉颃强

    2009-01-01

    This paper reports Hf isotope and REE composition of zircons from metamorphic rocks in the Daqing Mountains, Inner Mongolia. Detrital zircons from two meta - sedimentary rock samples have [n(176Hf)/n(177Hf)]c, tDM1(Hf) and tDM2(Hf) ranging from 0. 281079~0. 281502, 2548~3000 Ma and 2612 ~ 3153 Ma and from 0. 280916 ~0. 281451, 2533 ~ 2717 Ma and 2600 ~ 3404 Ma, respectively. The eHf (t) and tym (Hf) of magmatic zircon from one meta-gabbro sample range from-5. 45 -6.68 and 2319-2647 Ma, respectively. These indicate that late Neoarhcaean - early Palaeoproterozoic tectono-magmatic events occurred in the Daqing Mountains and adjacent areas, with both mantle addition and crustal recycling. Metamorphic zircon rims commonly show young tDM2 (Hf) when comparing with detrital and magmatic zircon cores, suggesting that Lu-Hf compositions of the rocks and minerals were changed during metamorphic processes. Metamorphic zircon rims are similar in REE pattern to adjacent detrital and magmatic cores, but commonly being lower in total REE content. Most of the metamorphic rims are smaller than 0. 1 in Th/U ratio, being quite different from the cores which Th/U ratios are generally higher than 0. 5. It is speculated that metamorphic fluid was high in w(176Hf)/w(177Hf) ratio and U and low in Th and REE and played an important role in metamorphic zircon formation.%本文报道了内蒙古大青山地区早前寒武纪变质岩石的锆石Hf同位素和稀土组成.两个古元古代晚期(1.9~2.1 Ga)变质碎屑沉积岩样品中碎屑锆石的[n(176Hf)/n(177Hf)]c、tDM1(Hf)和tDM2(Hf)分别为0.281079~0.281502、2548~3000 Ma、2612~3153 Ma和0.280g16~0.281451、2533~2717 Ma、2600~3404 Ma;一个古元古代早期(2.37 Ga)变质辉长岩样品中岩浆锆石的εHf(t)和tDM1(Hf)分别为1.50~6.68和2449~2647 Ma,表明大青山及邻区在新太古代晚期-古元古代早期存在强烈的构造岩浆热事件,既有地幔添加又有壳内再循环作用.三个样

  17. On bigraded regularities of Rees algebra

    Indian Academy of Sciences (India)

    RAMAKRISHNA NANDURI

    2017-09-01

    For any homogeneous ideal $I$ in $K[x_{1}, . . . , x_{n}]$ of analytic spread $\\ell$, we show that for the Rees algebra $R(I)$, $\\rm{reg^{syz}_ {(0,1)}}\\sl(R(I)) = \\rm{reg^{T}_{(0,1)}}\\sl(R(I))$. We compute a formula for the (0, 1)-regularity of $R(I)$, which is a bigraded analog of Theorem1.1 of Aramova and Herzog $(\\it{Am. J. Math.} \\bf{122(4)} (2000) 689–719)$ and Theorem 2.2of Römer $(\\it{Ill. J. Math.} \\bf{45(4)} (2001) 1361–1376)$ to $R(I)$. We show that if the defect sequence, $e_{k} := {\\rm reg}(I^k)− k \\rho(I)$, is weakly increasing for $k\\geq\\rm{reg^{syz}_{(0,1)}}\\sl(R(I))$, then $\\rm{reg}\\sl(I^{j}) = j\\rho(I) + e$ for $j\\geq \\rm{reg^{syz}_{(0,1)}}\\sl(R(I)) + \\ell$, where $\\ell = {\\rm min}\\{\\mu(J)\\mid J \\subseteq I$ a graded minimal reduction of $I\\}$. This is an improvement of Corollary 5.9(i) of [16].

  18. REE geochemistry of auriferous quartz carbonate veins of Neoarchean Ajjanahalli gold deposit, Chitradurga schist belt, Dharwar Craton, India

    Directory of Open Access Journals (Sweden)

    S. Sarangi

    2013-03-01

    Full Text Available REE composition of the carbonates of the auriferous quartz carbonate veins (QCVs of the Neoarchean Ajjanahalli gold deposit, Chitradurga schist belt, Dharwar Craton, is characterized by U-shaped chondrite normalized REE patterns with both LREE and HREE enrichment and a distinct positive Eu anomaly. As positive Eu anomaly is associated with low oxygen fugacity, we propose that the auriferous fluids responsible for gold mineralization at Ajjanahalli could be from an oxygen depleted fluid. The observed positive Eu anomaly is interpreted to suggest the derivation of the auriferous fluids from a mantle reservoir. The location of Ajjanahalli gold deposit in a crustal scale shear zone is consistent with this interpretation.

  19. Mineralogy, geochemistry and origin of Zafarabad iron deposit based on REE and trace elements of magnetite

    Directory of Open Access Journals (Sweden)

    Mehrdad Barati

    2013-10-01

    Full Text Available Zafarabad iron deposit is located northwest of Divandareh, in the northern margin of Sanandaj-Sirjan plutonic-metamorphic zone. The deposit is in lentoid to tubular shape, within a shear zone and occrrued in host rocks of calc-schist and limestone. Magnetite with massive, cataclastic and replacement textures are the main phases, while pyrite and other sulfide minerals are found. Major and trace elements are measured by ICP-MS and ICP-AES methods. Based on some ratios of trace elements in the ore samples and (Ti+V vs. Cal+Al+Mn and Ti+V vs. Ni/(Cr+Mn diagrams which are used for classification of iron deposit types, Zafarabad iron deposit fall in the range of skarn deposits. Spider diagrams show a steady decline from LREE to HREE elements with Eu (mean value of 0.06 ppm and Ce (mean value of 0.94 ppm negative anomalies. Comparing the distribution patterns of REE for the Zafarabad magnetites with those of various types of iron deposits shows that the REE pattern for Zafarabad is similar to these deposits. Analysis of calculated parameters for REE shows that the hydrothermal fluids responsible for mineralization are mainly of magmatic origin through fractionation and crystallization processes of a deep iron rich fluid phase and its emplacement within the carbonate rocks, forming iron skarn.

  20. REE Characteristics of Microfine Disseminated Gold Ores in Danzai,Guizhou

    Institute of Scientific and Technical Information of China (English)

    陈庆年; 周丕康; 等

    1998-01-01

    Described in this paper are the fundamental characteristics of mineralization of gold ores in the Sandu-Danzhai Hg-Sb-Au ore belt of Guizhou Province,Through systematic sampling of the industrial orebody and alteration zone,the total amount of the rare-earth elements,that of the light rare-earth elements,Eu depletion and other parameters are clarified.There have been distinguished two types of REE distribution patterns:the"Clay type"and the "quartz type" .High-grade orebodies are closely related with silicification,illitization and pyritization.The seven-component diagram of the REEs of even numbers in the periodic table(Bal-asov,1966)is capable of distinguishing ore-bearing from ore-barren deposits.

  1. Geochemical Behaviors of REE and Other Trace Elements during the Formation of Strata-bound Skarns and Related Deposits:A Case Study of the Dongguashan Cu(Au) Deposit,Anhui Province,China

    Institute of Scientific and Technical Information of China (English)

    LING Qicong; LIU Congqiang

    2003-01-01

    REE and other trace elements in the altered marbles, massive skarns and ores, as well as garnet and quartz were determined in order to examine the behaviors of trace elements during hydrothermal alteration. It is demonstrated that the high-field-strength (HFS) elements Zr, Hf, Th and Nb were immobile while other trace elements were mobile during the formation of skarns and related deposits. REE and ore-forming elements such as Cu and Ag in hydrothermally-altered marbles and skarns were provided primarily by hydrothermal fluids. In the direction transverse of the strata, the more deeply the marbles were altered, the higher the total REE abundance and the larger the negative Eu anomalies would be. The chondrite-normalized REE patterns of skarns are similar to those of the marbles, but the former are distinguished by much higher REE contents and more remarkable negative Eu anomalies. Those patterns were apparently not inherited from the marble protolith, but were controlled by garnets, which were determined by the hydrothermal solutions involved in the infiltration metasomatism. The hydrothermal fluids are characterized by having slightly right-hand dipping REE patterns, being enriched in LREE and having strongly negative Eu anomalies. The uptake of REE from hydrothermal fluids during the growth of garnet crystals resulted in the garnets having similar REE patterns to the hydrothermal fluids. Based on the spatial variation of REE in skarns and the structures of the hosting strata, we can get a better understanding of the transport path and pattern of the fluids involved in the formation of skarns and their related deposits. REE geochemistry investigation can help elucidate the genesis of skarns and skarn-related deposits.

  2. REE geochemical characteristics of the No. 302 uranium deposit in northern Guangdong, South China

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The No. 302 uranium deposit, located in Guangdong Province, is a typical granite-type uranium ore deposit. REE geochemical characteristics of the wall rocks, pitchblende, altered rocks, calcite and fluorite from this deposit have been systematically studied in this paper. The result showed that the alkali-metasomatic granites and other altered rocks have the same REE distribution patterns as Indosinian granites. It is indicated that the hydrothermal ore-forming solution had altered the Indosinian granites, and ore-forming materials may directly originate from the Indosinian granites. Calcite and fluorite of different stages are the products derived from the same source but different stages. The evolution and degassing of the mineralizing solution might induce LREE enrichment to varying degree. Mantle fluid and a large volume of mineralizer may be the crucial factors controlling uranium mineralization, and the hydrothermal solution with mineralizer played an important role in U transport and concentration. Meanwhile, the degassing of CO2 might promote U and REE precipitation.

  3. Mass-spectrometric REE analysis in sulphide minerals

    Directory of Open Access Journals (Sweden)

    Irina R. Elizarova

    2012-01-01

    Full Text Available The standard samples of diorite, granite and anorthosite (National Centre for Petrographic and Geochemical Research (CRPG CNRS, Nancy, France were analyzed to measure rare-earth element (REE concentrations by the ICP MS method (quadrupole ELAN 9000 DRC-e without preliminary dilution and concentration procedures. The certified values of REE concentrations measured on ELEMENT-2 mass-spectrometer by ICP MS method in Nancy are also well reproduced on ELAN 9000. The mass-spectrometer analytical environment and modes of operation were adjusted to detect REE in sulphide minerals by the example of the pyrite from the PGE Penikat layered intrusion (Finland and chalcopyrite from the Talnakh deposit (Kazakhstan. The total REE content in the pyrite is ca. 3.5 ppm, that is enough to establish Sm-Nd age of pyrite. By the example of State Standard Sample 2463 (Apatite, Russia it is shown how to apply the mineral/chondrite spectra to evaluate the accuracy of the REE analytical results.

  4. Discrimination of sediment provenance in the Yellow Sea: Secondary grain-size effect and REE proxy

    Science.gov (United States)

    Jung, Hoi-Soo; Lim, Dhongil; Jeong, Do-Hyun; Xu, Zhaokai; Li, Tiegang

    2016-06-01

    This study analyzed grain size and elemental concentrations (Al, Mg, Fe, and rare earth elements (REEs)) in 91 surface sediments to elucidate sediment provenance in the Yellow Sea. Elemental concentrations were normalized by Al concentration (Celement/CAl) to minimize the sediment grain-size effect (GSE). However, noticeable linear relationships between Al concentration (or mean grain size) and the ratio (e.g., Mg/Al or Fe/Al) appeared unexpectedly in pair diagrams. The spatial distribution patterns of Fe/Al and Mg/Al ratios were also similar to the pattern of mean grain size. This implies that the GSE was not removed completely, even after the normalization process. Thus, great care must be taken when applying the ratios of Celement/CAl as a proxy of sediment provenance. To improve provenance discrimination of the sediments in the Yellow Sea, the difference between the REE distribution patterns of Chinese and Korean river sediments, expressed as δ (δ = REE∗(La) - REE∗(Lu)), was calculated, and the spatial distribution patterns of the δ values were mapped. The δ values gradually increased from the western to the eastern part of the Yellow Sea, except for low δ values in the southeastern part of the Yellow Sea. This result indicates that the majority of Chinese and Korean river sediments are accumulating near to their respective coasts, except for a deposit along the southwestern coast of Korea in which a considerable amount of sediment from Chinese rivers has been accumulating.

  5. Geochemistry of Monazite within Carbonatite Related REE Deposits

    Directory of Open Access Journals (Sweden)

    Wei Chen

    2017-09-01

    Full Text Available Approximately >50% of global rare earth element (REE resources are hosted by carbonatite related deposits, of which monazite is one of the most important REE minerals. Monazite dominates more than 30 carbonatite-related REE deposits around the world, including currently exploited mineralization at Bayan Obo and Mount Weld. These deposits are widely distributed across all continents, except Antarctica. Though rare, monazite occurs as the primary mineral in carbonatite, and mostly presents as a secondary mineral that has a strong association with apatite. It can partially or completely replace thin or thick overgrowth apatite, depending on the availability of REE. Other mineral phases that usually crystallize together with monazite include barite, fluorite, xenotime, sulfide, and quartz in a carbonate matrix (e.g., dolomite, calcite. This review of monazite geochemistry within carbonatite-related REE deposits aims to provide information regarding the use of monazite as a geochemical indicator to track the formation history of the REE deposits and also supply additional information for the beneficiation of monazite. The chemical compositions of monazite are highly variable, and Ce-monazite is the dominant solid solution in carbonatite related deposits. Most monazite displays steep fractionation from La to Lu, absent of either Eu or Ce anomalies in the chondrite normalized REE plot. The other significant components are huttonite and cheratite. Some rare sulfur-bearing monazite is also identified with an SO3 content up to 4 wt %. A 147Sm/144Nd ratio with an average ~0.071 for monazite within carbonatite-related ores is similar to that of their host rocks (~0.065, and is the lowest among all types of REE deposits. Sm/Nd variation of monazite from a single complex reflects the differentiation stage of magma, which decreases from early to late. Based on the differences of Nd and Sr abundances, Nd isotopic composition for monazite can be used to track

  6. Trace elements and REE geochemistry of Middle Devonian carbonate mounds (Maïder Basin, Eastern Anti-Atlas, Morocco): Implications for early diagenetic processes

    Science.gov (United States)

    Franchi, Fulvio; Turetta, Clara; Cavalazzi, Barbara; Corami, Fabiana; Barbieri, Roberto

    2016-08-01

    Trace and rare earth elements (REEs) have proven their utility as tools for assessing the genesis and early diagenesis of widespread geological bodies such as carbonate mounds, whose genetic processes are not yet fully understood. Carbonates from the Middle Devonian conical mud mounds of the Maïder Basin (eastern Anti-Atlas, Morocco) have been analysed for their REE and trace element distribution. Collectively, the carbonates from the Maïder Basin mud mounds appear to display coherent REE patterns. Three different geochemical patterns, possibly related with three different diagenetic events, include: i) dyke fills with a normal marine REE pattern probably precipitated in equilibrium with seawater, ii) mound micrite with a particular enrichment of overall REE contents and variable Ce anomaly probably related to variation of pH, increase of alkalinity or dissolution/remineralization of organic matter during early diagenesis, and iii) haematite-rich vein fills precipitated from venting fluids of probable hydrothermal origin. Our results reinforce the hypothesis that these mounds were probably affected by an early diagenesis induced by microbial activity and triggered by abundance of dispersed organic matter, whilst venting may have affected the mounds during a later diagenetic phase.

  7. REE and Strontium Partition Coefficients for Nakhla Pyroxenes

    Science.gov (United States)

    Oe, K.; McKay, G.; Le, L.

    2001-01-01

    We present new partition coefficients for REE and Sr determined using a synthetic melt that crystallizes pyroxenes very similar in composition to Nakhla pyroxene cores. We believe these are the most appropriate partition coefficients to use in studying Nakhla Additional information is contained in the original extended abstract..

  8. Vapour transport of rare earth elements (REE) in volcanic gas: Evidence from encrustations at Oldoinyo Lengai

    Science.gov (United States)

    Gilbert, C. D.; Williams-Jones, A. E.

    2008-10-01

    Fumarolic encrustations and natrocarbonatite lava from the active crater of Oldoinyo Lengai volcano, Tanzania, were sampled and analysed. Two types of encrustation were distinguished on the basis of their REE content, enriched (~ 2800-5600 × [REE chondrite]) and depleted (~ 100-200 × [REE chondrite]) relative to natrocarbonatite (1700-1900 × [REE chondrite]. REE-enriched encrustations line the walls of actively degassing fumaroles, whereas REE-depleted encrustations occur mainly along cracks in and as crusts on cooling natrocarbonatite lava flows; one of the low REE encrustation samples was a stalactite from the wall of a possible fumarole. The encrustations are interpreted to have different origins, the former precipitating from volcanic gas and the latter from meteoric/ground water converted to steam by the heat of the overlying lava flow(s). REE-profiles of encrustations and natrocarbonatite are parallel, suggesting that there was no preferential mobilization of specific REE by either volcanic vapour or meteoric water vapour. The elevated REE-content of the first group of encrustations suggests that direct REE-transport from natrocarbonatite to volcanic vapour is possible. The REE trends observed in samples precipitating directly from the volcanic vapour cannot be explained by dry volatility based on the available data as there is no evidence in the encrustation compositions of the greatly enhanced volatility predicted for Yb and Eu. The observed extreme REE-fractionation with steep La/Sm slopes parallel to those of the natrocarbonatite reflects solvation and complexation reactions in the vapour phase that did not discriminate amongst the different REE or similar transport of REE in both the natrocarbonatite magma and its exsolving vapour. The low concentrations of REE in the encrustations produced by meteoric vapour suggest that the temperature was too low or that this vapour did not contain the ligands necessary to permit significant mobilization of the REE.

  9. Rare earth elements in sedimentary phosphate deposits: Solution to the global REE crisis?

    Science.gov (United States)

    Emsbo, Poul; McLaughlin, Patrick I.; Breit, George N.; du Bray, Edward A.; Koenig, Alan E.

    2015-01-01

    The critical role of rare earth elements (REEs), particularly heavy REEs (HREEs), in high-tech industries has created a surge in demand that is quickly outstripping known global supply and has triggered a worldwide scramble to discover new sources. The chemical analysis of 23 sedimentary phosphate deposits (phosphorites) in the United States demonstrates that they are significantly enriched in REEs. Leaching experiments using dilute H2SO4 and HCl, extracted nearly 100% of their total REE content and show that the extraction of REEs from phosphorites is not subject to the many technological and environmental challenges that vex the exploitation of many identified REE deposits. Our data suggest that phosphate rock currently mined in the United States has the potential to produce a significant proportion of the world's REE demand as a byproduct. Importantly, the size and concentration of HREEs in some unmined phosphorites dwarf the world's richest REE deposits. Secular variation in phosphate REE contents identifies geologic time periods favorable for the formation of currently unrecognized high-REE phosphates. The extraordinary endowment, combined with the ease of REE extraction, indicates that such phosphorites might be considered as a primary source of REEs with the potential to resolve the global REE (particularly for HREE) supply shortage.

  10. Effects of rare earth elements and REE-binding proteins on physiological responses in plants.

    Science.gov (United States)

    Liu, Dongwu; Wang, Xue; Chen, Zhiwei

    2012-02-01

    Rare earth elements (REEs), which include 17 elements in the periodic table, share chemical properties related to a similar external electronic configuration. REEs enriched fertilizers have been used in China since the 1980s. REEs could enter the cell and cell organelles, influence plant growth, and mainly be bound with the biological macromolecules. REE-binding proteins have been found in some plants. In addition, the chlorophyll activities and photosynthetic rate can be regulated by REEs. REEs could promote the protective function of cell membrane and enhance the plant resistance capability to stress produced by environmental factors, and affect the plant physiological mechanism by regulating the Ca²⁺ level in the plant cells. The focus of present review is to describe how REEs and REE-binding proteins participate in the physiological responses in plants.

  11. Sm-Nd dating and REE Composition of scheelite for the Honghuaerji scheelite deposit, Inner Mongolia, Northeast China

    Science.gov (United States)

    Guo, Zhijun; Li, Jinwen; Xu, Xinying; Song, Zeyou; Dong, Xuzhou; Tian, Jing; Yang, Yuncheng; She, Hongquan; Xiang, Anping; Kang, Yongjian

    2016-09-01

    Sm-Nd analyses of seven scheelite samples from scheelite-quartz veins in the Honghuaerji scheelite deposit produce a well-defined linear array on an isochron diagram with a mean square weighted deviation (MSWD) of 0.87 corresponding to an age of 178.4 ± 2.9 Ma with εNd(t) = + 1.50. This age is interpreted to represent the age of scheelite mineralization. The scheelite Sm-Nd age is in good agreement with U-Pb ages obtained from a mineralization-related granite (179.4 ~ 178.6 Ma), indicating that there is no apparent age gap between granite crystallization and ore formation. Rare earth element (REE) abundances in the scheelite were determined by in situ laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS), and the scheelite samples contain elevated REE concentrations with total ΣREE + Y contents in the range of 3339 to 6321 ppm. The chondrite-normalized REE distribution patterns of all scheelites are middle REE (MREE)-enriched, with strong negative Eu-anomalies (Eu/Eu* = 0.09 ~ 0.23). The REE characteristics of the Honghuaerji scheelite suggest that REE3 + substituted into the Ca site along with Na and Nb (dominated by Na), whereas Eu is predominantly present as Eu2 + in the scheelite and may have crystallized from relatively reduced fluids. All sulfur isotope data (δ34S) for sulfide separates range from + 2.0 to + 3.8‰, with an average of 3.2‰. Measured 206Pb/204Pb, 207Pb/204Pb, and 208Pb/204Pb ratios vary from 18.243 to 18.451, 15.494 to 15.574, and 37.933 to 38.340, respectively. On the basis of common Sr-Nd-Pb-Hf isotopic characteristics between the scheelite and the host granite and the positive initial Nd isotope ratios (+ 1.46 - + 1.52), low 87Sr/86Sr ratios (0.704983-0.705297) in the scheelites, it is inferred that the hydrothermal fluids responsible for tungsten mineralization at Honghuaerji were of magmatic origin with a mantle-derived signature. Based on the regional geology, tectonic evolution, and geochemical evidence, the

  12. Systematic Investigation of REE Mobility and Fractionation During Continental Shale Weathering Along a Climate Gradient

    Science.gov (United States)

    Jin, L.; Ma, L.; Dere, A. L. D.; White, T.; Brantley, S. L.

    2014-12-01

    Rare earth elements (REE) have been identified as strategic natural resources and their demand in the United States is increasing rapidly. REE are relatively abundant in the Earth's crust, but REE deposits with minable concentrations are uncommon. One recent study has pointed to the deep-sea REE-rich muds in the Pacific Ocean as a new potential resource, related to adsorption and concentration of REE from seawater by hydrothermal iron-oxyhydroxides and phillipsite (Kato et al., 2010). Finding new REE deposits will be facilitated by understanding global REE cycles: during the transformation of bedrock into soils, REEs are leached into natural waters and transported to oceans. At present, the mechanisms and factors controlling release, transport, and deposition of REE - the sources and sinks - at Earth's surface remain unclear. Here, we systematically studied soil profiles and bedrock in seven watersheds developed on shale bedrock along a climate transect in the eastern USA, Puerto Rico and Wales to constrain the mobility and fractionation of REE during chemical weathering processes. In addition, one site on black shale (Marcellus) bedrock was included to compare behaviors of REEs in organic-rich vs. organic-poor shale end members under the same environmental conditions. Our investigation focused on: 1) the concentration of REEs in gray and black shales and the release rates of REE during shale weathering, 2) the biogeochemical and hydrological conditions (such as redox, dissolved organic carbon, and pH) that dictate the mobility and fractionation of REEs in surface and subsurface environments, and 3) the retention of dissolved REEs on soils, especially onto secondary Fe/Al oxyhydroxides and phosphate mineral phases. This systematic study sheds light on the geochemical behaviors and environmental pathways of REEs during shale weathering along a climosequence.

  13. Mineralogy and REE geochemistry at Gomish-Tappeh Zn-Pb-Cu (Ag deposit, southwest of Zanjan

    Directory of Open Access Journals (Sweden)

    Tooba Salehi

    2010-11-01

    Full Text Available Gomish-Tappeh Zn-Pb-Cu (Ag deposit is located 90 km southwest of Zanjan, in northwestern part of Urumieh-Dokhtar volcano-plutonic zone. Exposed rocks at the area include Oligo-Miocene volcano-sedimentary and sedimentary sequences as well as Pliocene volcano-plutonic sequence (andesite porphyry dykes, dacitic subvolcanic dome and rhyodacitic volcanics. Alteration in the deposit developed as silicic, silicic-sulfidic, sericitic, carbonate, argillic and propylitic. Main mineralization at the Gomish-Tappeh deposit is observed as veins occurring in a steeply-deeping normal fault defined by an NE-SW trend in host rocks such as dacitic crystal litic tuff, dacitic subvolcanic dome, specifically the rhyolitic tuff. Paragenetic minerals in the ore veins consist of pyrite, arsenopyrite, chalcopyrite, bornite, low-Fe sphalerite, galena, tetrahedrite and specularite. Gangue minerals accompanying the ores include quartz, calcite, chlorite, sericite and clay minerals. Based on geochemical data, average grades for samples from the ore veins at the Gomish-Tappeh deposit are: 4% Pb, 6% Zn, 2% Cu and 88 ppm Ag. Moreover, REE distribution patterns for altered samples of the dacitic subvolcanic dome and acidic tuff when compared with fresh samples, show enrichment in LREE, while HREE demonstrate various bahaviours. The negative Eu anomaly in chondrite-normalized REE patterns for these rocks is related to the increase in fluid/rock ratio and destruction of those grains of plagioclase enriched in Eu. REE distribution patterns for the silty tuff (footwall to the ore compared with acidic tuff represent enrichment in all REE as well as positive Eu anomalies. However, the ore samples indicate more enrichment in LREE/HREE ratios and higher Eu contents when compared with wallrock of the ore veins (silty tuff. This is due to the influence of chloric magmatic-hydrothermal fluids that caused alteration along the ore zone, releasing LREE and Eu from the host rocks and finally

  14. REE composition in scheelite and scheelite Sm-Nd dating for the Xuebaoding W-Sn-Be deposit in Sichuan

    Institute of Scientific and Technical Information of China (English)

    LIU Yan; DENG Jun; LI ChaoFeng; SHI GuangHai; ZHENG AiLi

    2007-01-01

    The scheelite with large size and euhedral shape from Xuebaoding, Sichuan Province is an ideal mineral to study REE patterns and Sm-Nd dating of non-gold deposits. The scheelite has diameters of 1―10 cm and colors of pale beige to deep orange. Most of these scheelites occur in association with beryl, cassiterite and muscovite. The rare earth elements indicate that scheelite samples from Xuebaoding W-Sn-Be deposits contain high concentrations of rare earth elements with total ΣREE+Y contents in the range of 369―1725 μg·g(-)1 and nearly all of these scheelite samples are enriched in LREE and depleted in HREE and have negative Eu anomalies. The REE patterns of the scheelites are similar to those of A-type granite with obvious tetrad effect, similar to that of type II scheelites. Based on reported fluid inclusion studies, the mineralizing-fluid of the Xuebaoding W-Sn-Be deposit indicates low Na activity. The REE patterns of the scheelite are probably controlled by partition coefficient in hydrothermal fluid. In the 147Sm/144Nd-143Nd/144Nd diagram, the scheelites show a linear array corresponding to an isochron age of 182.0±9.2 Ma (MSWD = 0.52). The Sm-Nd age represents the formation age of the scheelite and can indicate that the W, Sn and Be mineralization at Xuebaoding took place in the Early Yanshanian. The Sm-Nd dating result is important for the study of the multi-metal resources in western Sichuan Province.

  15. Geochemistry of carbonatites in Maoniuping REE deposit, Sichuan Province, China

    Institute of Scientific and Technical Information of China (English)

    许成; 黄智龙; 刘丛强; 漆亮; 李文博; 管涛

    2003-01-01

    Carbonatites in the Maoniuping REE deposit, Sichuan Province, which are spatially and temporally associated with rare earth mineralization, were emplaced at the time of Himalayan. The rocks are carbonatite-syenite complexes, with the mineral assemblages of calcite-aegirine-acmite- arfvedsonite-mica-orthoclase. The rocks are characterized by the enrichment in incompatible elements, such as Sr, Ba and REE, with C and O isotopic compositions of the "primary igneous carbonatites", relatively high initial 87Sr/86Sr ratios and low ??Nd values. All of these suggest that the rocks were derived from the metasomatic enriched mantle. It is demonstrated by geological and geochemical evidence that the mixing of the Himalayan subducting crustal materials with mantle source EM1 is probably the main factor responsible for the formation of carbonatites. The carbonatite-syenite complexes were generated from liquid immiscibility of CO2-rich alkalic silicate magma, which was derived from partial melting of the metasomatic mantle.

  16. REE Biological Metallogeny —A Preliminary Study

    Institute of Scientific and Technical Information of China (English)

    陈志澄; 余受均; 等

    1995-01-01

    Five species of bacteria have been found in granite-weathering profiles of Ore District 701.They tend to decrease in varieties and quantities from the upper part down-ward, and no bacterium has been brought up below the depth of 10 m.The simulating experiments done by using humic acid of small molecular weight ,and decanedioic acid extracted from the samples and the bacteria mentioned above have shown that:(1)The dissolving rates of REEs from humic acid+original rock or decanedioic acid +original rock are lower than those from humic acid +bacteria +original rock or decanedioic acid +bacteria+original rock.The presence of bacteria may accelerate the formation of REE-organic complexes and make the complexes increase in quantity.Aminoacids in the bacteria are involved in coordination balance.The concentrations of the complexes tend to increase as a result of the formation of the complexes,i.e., the dissolution, complexation, migration and accumulation of REEs from the original rocks will be accelerated.(2)The metabolism of microorganisms has contributed a lot to keeping a pH environment in the weathering crust.

  17. REE Comparison Between Muncung Granite Samples and their Weathering Products, Lingga Regency, Riau Islands

    Directory of Open Access Journals (Sweden)

    Ronaldo Irzon

    2016-12-01

    Full Text Available The increasing demand for Rare Earth Elements (REE is related to the continous development of technology, and these elements are used in modern equipments. REE can occur in igneous and sedimentary rocks in significant amounts as primary deposits, whereas the secondary REE deposit can be produced by intensive lateritic weathering of bedrocks under the tropical or subtropical climate. Lateritic process can increase REE concentration from sub-economic levels in host rocks to be more valuable. Muncung Granite is located in a tropical area of Lingga Regency, Riau Islands Province. REE occurs in the Muncung Granite and in weathered layers (saprolite, laterite, and soil. ICP-MS was applied to measure the REE content in all samples of this study. The average REE content of the Muncung Granite is 265 ppm with Eu anomaly in REE’s spider diagrams. Lateritization process has increased REE content by more than four times compared to that in the Muncung Granite. Ce and Eu anomalies in weathered layers can be associated with weathering process and initial REE contents in the host rock. Ce anomaly in a laterite layer is found to have a negative correlation to REE total enrichment. The REE level in the Muncung Granite is higher than the content in the soil and saprolite layers, but lower than that in the laterite.

  18. Audre's daughter: Black lesbian steganography in Dee Rees' Pariah and Audre Lorde's Zami: A New Spelling of My Name.

    Science.gov (United States)

    Kang, Nancy

    2016-01-01

    This article argues that African-American director Dee Rees' critically acclaimed debut Pariah (2011) is a rewriting of lesbian poet-activist Audre Lorde's iconic "bio-mythography" Zami: A New Spelling of My Name (1982). The article examines how Rees' work creatively and subtly re-envisions Lorde's Zami by way of deeply rooted and often cleverly camouflaged patterns, resonances, and contrasts. Shared topics include naming, mother-daughter bonds, the role of clothing in identity formation, domestic abuse, queer time, and lesbian, gay, bisexual, and transgender legacy discourse construction. What emerges between the visual and written texts is a hidden language of connection--what may be termed Black lesbian steganography--which proves thought-provoking to viewers and readers alike.

  19. Concentration, Distribution, and Occurrence of REEs in Coals from Chongqing, Southwest China

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The concentration, distribution, and occurrence of rare earth elements (REEs) in coals as well as stone coals in different geological periods from Chongqing were studied. The results show that the REE content in coals from Chongqing is much higher than that of the ordinary Chinese coals, the Late Paleozoic coals from North China, US coals, and the world coals. Although the concentration of light rare earth elements (LREE) is higher than that of heavy rare earth elements (HREE), the ratio of LREE to HREE is as low as 5.11. The REE content decreases with the coal-formation periods from old to new. The REE content in the Sinian stone coal is the highest, but it is the lowest in Early Jurassic coals. The similar REE contents in bituminous coals and anthracite show that the metamorphism has a little influence on REE content in coal. In addition, silicate association dominates the occurrence mode of REEs in coals from Chongqing.

  20. Mineralogical evolution and REE mobility during crystallisation of ancylite-bearing ferrocarbonatite, Haast River, New Zealand

    Science.gov (United States)

    Cooper, Alan F.; Collins, Alice K.; Palin, J. Michael; Spratt, John

    2015-02-01

    Ferrocarbonatites from the lamprophyric Alpine Dyke Swarm, south Westland, New Zealand are composed of dolomite-calcite-albite-hematite and contain interstitial patches dominated by calcite-ancylite-barite-monazite-thorite-albite-aeschynite-analcime, interpreted as modified late-stage segregations. The dominant carbonate in the ferrocarbonatite is a ferroan dolomite that contains vermicular and blocky patches of calcite and a more Fe-rich ankerite. The calcite is interpreted as the product of exsolution or the by-product, with dolomite and hematite, of the oxidation of primary ankerite during interaction with hydrothermal fluids. Late stage ancylite-rich segregations have elevated 87Sr/86Sr compositions relative to host carbonatite suggesting they have crystallised from fluids that have equilibrated with host schist, but with the REE derived from fractionation of ferrocarbonatite. Mineral veining indicates this stage of crystallisation post-dated the ankerite to dolomite replacement. The carbonatites, as inferred from mineral associations, textures and carbonate geothermometry, have a complex history of recrystallisation from late stage, low temperature carbo-hydrothermal fluids. All carbonatitic phases have convex-upward chondrite normalised REE patterns enriched in Nd, and are relatively depleted in lighter LREE and in HREE. Depletion in La and Ce is attributed to either complementary enrichment in felsic magmas during initial separation of carbonatite, or more likely, to subsequent preferentially enhanced mobility of La- and Ce-Cl- complexes in low-temperature aqueous fluids.

  1. Aeromagnetic expression of rare earth element (REE) deposits in New Mexico, USA

    Science.gov (United States)

    Li, M.

    2016-12-01

    With the development of high-tech devices and the expanding demands in industrial production, rare earth elements(REE) has been playing an increasingly important role in the global economy in the past several decades. Different types of REE serve irreplaceable functions in high-tech industry, as well as for developing sustainable energy and catalysis of manufacturing. Given that the global supply of REE has become strained since 2009 and no known substitutes for REE have been found, exploration for new REE deposits is imperative for economic sustainability. Ten main regions have REE deposits in New Mexico, some of which have not been exploited, while some sites such as Gallinas mountains vein deposits are in early exploration stage. Exploration for the reserves and quantization of mineral compositions of New Mexico's REE depositional districts can have economic benefits in general. In this study, high-resolution airborne magnetic and gravity data were used for studying the Gallinas mountains REE deposit. The purposes of this study are to: (1) characterize specific aeromagnetic anomaly and gravity features from the REE deposits, and (2) apply the characterized features to suggest other areas among the ten REE depositional regions for further exploration. All REE deposits in the study area are found associated with alkaline to alkali-calcic volcanic rocks. A quantitative modeling based on aeromagnetic and gravity anomaly mapping was constructed with an assumption of three units: carbonatites, alkaline volcanic intrusions and REE-concentrated minerals (barite, bastnaesite, etc.). The results of this study show that alkaline deposit is characterized by negative magnetic anomalies and carbonatite is associated with gravity anomaly and vertical gravity gradient high. The area with significantly high aeromagnetic anomaly area and also gravity anomaly high supposed to reflect REE-concentrated minerals such as bastnaesite. For further research, hyperspectral information and

  2. A study of REE and Pb, Sr and Nd isotopes in garnet-lherzolite xenoliths from Mingxi, Fujian Province

    Science.gov (United States)

    Wankang, H.; Junwen, W.; Basu, A.R.; Tatsumoto, M.

    1993-01-01

    The REE and Pb, Sr, Nd isotopes in three xenoliths from limburgite and scoria-breccias, including spinel-lherzolite, spinel-garnet-lherzolite and phlogopite-gamet-lherzolite, were analysed. The REE contents of the xenoliths are 1.3 to 3.3 times those of the chondrites with their REE patterns characterized by weak LREE depletion. The143Nd/144Nd values of whole rocks and minerals range from 0.51306 to 0.51345 with ??Nd=+ 8.2- +15.8,206Pb/204 Pb < 18.673, and207Pb/204Pb < 15.574. All this goes to show that the upper mantle in Mingxi at the depth of 67-82 km is a depleted mantle of MORB type, with87Sr/86 Sr ratios 0.70237-0.70390. In Nd-Sr diagram the data points of whole rocks are all out of the mantle array, implying that the xenoliths from Mingxi have more radiogenic Sr isotopes than those of the mantle array. ?? 1993 Institute of Geochemistry, Chinese Academy of Sciences.

  3. REE mobility during the alteration of Carbonatite and their economic potential.

    Science.gov (United States)

    Marien, Christian; Dijkstra, Arjan; Wilkins, Colin

    2016-04-01

    The supply risk of Rare Earth Elements is an unpredictable economic factor for the future application and development of modern technology for the EU. Therefore a better understanding of REE mobilisation during hydrothermal alteration of Carbonatites is essential for a safer supply of REE in general. The hydrothermal alteration of Carbonatite within the Fen Complex (Norway) forms a fine grained red hematized rock type, called Rødbergite, which is partially enriched in REE. The variation of REE within the Rødbergite is poorly understood and problematic for any future REE exploitation from Rødbergite. A genetic model of the formation of Rødbergite will provide more information about the economic potential of Rødbergite. The gradual transformation of carbonatite to Rødbergite is not easily observable due to sparse outcrop in the Fen Complex. A fresh road cut near the Bjørndallen farm (Fen Complex) provides a unique insight to the progressive hydrothermal alteration from carbonatite to Rødbergite and is therefore crucial for a genetic model of the formation of Rødbergite. 14 Samples were taken along the profile. The mineralogical, geochemical and textural characterization of the samples using the SEM as well as major-, trace- and isotopic elemental data revealed the breakdown of the primary minerals due to the infiltration of an oxidizing fluid along grain boundaries. The primary REE-minerals in unaltered Carbonatite are REE fluorocarbonates. With the increasing alteration to Rødbergite REE fluorocarbonates are progressively replaced by hematite. In contrast, monazite - a REE-phosphate - is the dominant REE mineral species in the Rødbergite. A transitional Rødbergite sample shows apatite aggregates with a strong preferential concentration of monazite along the rim of the apatite aggregates. This observation provides strong evidence for the solution of REE in the primary rock (carbonatite) by fluids and later precipitation of REE along phosphate bearing

  4. Clinical aspects of super-refractory schizophrenia: a 6-month cohort observational study Aspetos clínicos da esquizofrenia super-refratária: estudo observacional de coorte com seguimento de seis meses

    Directory of Open Access Journals (Sweden)

    Jorge Henna Neto

    2007-09-01

    Full Text Available OBJECTIVE: Approximately 30% of treatment-resistant schizophrenic patients do not fully respond to Clozapine and such patients are termed Clozapine non-responders or super-refractory schizophrenics. The aim of this study was to characterize patients with super-refractory schizophrenia according to demographic and psychopathological variables, as compared with patients with refractory schizophrenia or non-refractory subjects. METHOD: One hundred two outpatients meeting DSM-IV criteria for schizophrenia were followed-up for 6 months. Subjects were classified into 3 groups: non-refractory (n = 25, refractory (n = 43 and super-refractory (n = 34. Psychopathology was assessed by the Positive and Negative Syndrome Scale, the Schedule for Deficit Syndrome, the Calgary Depression Scale and the Quality of Life Scale. Patients were rated at 2-month intervals. RESULTS: Higher levels of severity at the disease onset as well as higher severity of positive symptoms were found to be predictive of super-refractoriness. CONCLUSIONS: The super-refractory schizophrenia patients have psychopathological predictive factors that need studies comparing brain images, genetical features and other clinical comparisons.OBJETIVO: Cerca de 30% dos pacientes de esquizofrenia resistentes ao tratamento não respondem completamente à clozapina. Esses pacientes são denominados não respondedores à clozapina ou portadores de esquizofrenia super-refratários. O objetivo deste estudo foi caracterizar pacientes com esquizofrenia super-refratária de acordo com as variáveis demográficas e psicopatológicas, em comparação com pacientes com esquizofrenia refratária e indivíduos não refratários. MÉTODO: Cento e dois pacientes ambulatoriais que preenchiam os critérios do DSM-IV para esquizofrenia foram acompanhados durante seis meses. Os indivíduos foram classificados em três grupos: não refratários (n = 25, refratários (n = 43 e super-refratários (n = 34. A

  5. Biogeochemistry of REE elements and tetrad effect in the soil-plant system: a study on volcanic rock covers in southernmost Brazil

    Directory of Open Access Journals (Sweden)

    Maria do Carmo Lima e Cunha

    2012-12-01

    Full Text Available This paper deals with the distribution of REE in rock, soil and plant in an area of monzonitic rocks from southernmost Brazil. The REE patterns in Schinus lensticifolius show a negative-Ce anomaly and a prominent tetrad effect, characterized as W-type that are not present in rock and soil samples. The REE patterns in the soils and rocks sampled are very similar and there is no fractionation of REE during the processes of soil formation. The W-type patterns are interpreted as indicating that REE were absorved by S. lentiscifolius as simple ions rather than as complex ions, or, alternatively, that the transport of REE in the plant metabolic processes was as free ions. The recognition of tetrads, either, M- or W-type patterns, is an additional tool for understanding the biogeochemistry of REE and can contribute to the study of monitoring processes of contaminated environment or to mineral prospecting.Este trabalho trata da distribuição dos ETR na rocha, solo e planta em área de ocorrência de rochas monzoníticas do extremo sul do Brasil. O padrão dos ETR em Schinus lentiscifolius apresenta anomalia negativa de Ce e significativo efeito tétrade, do tipo W, ausente no padrão da rocha e do solo. A configuração das curvas da rocha e do solo é similar e sem fracionamento das ETR durante a pedogênese. O padrão em W é interpretado como decorrente da absorção dos ETR pela planta na forma de íons livres e não complexados, ou, alternativamente, que o transporte das ETR nos processos metabólicos foi na forma de íons livres. O reconhecimento de tétrades, seja do tipo W ou M, é uma ferramenta adicional na compreensão da biogeoquímica dos ETR e pode contribuir para o estudo de processos de monitoramento de ambientes contaminados ou para pesquisas em prospecção mineral.

  6. Rees algebras of square-free monomial ideals

    CERN Document Server

    Fouli, Louiza

    2012-01-01

    We study the defining equations of the Rees algebra of square-free monomial ideals in a polynomial ring over a field. We determine that when an ideal $I$ is generated by $n$ square-free monomials of the same degree then $I$ has relation type at most $n-2$ as long as $n \\leq 5$. In general, we establish the defining equations of the Rees algebra in this case. Furthermore, we give a class of examples with relation type at least $n-2$, where $n=\\mu(I)$. We also provide new classes of ideals of linear type. We propose the construction of a graph, namely the generator graph of an ideal, where the monomial generators serve as vertices for the graph. We show that when $I$ is a square-free monomial ideal generated in the same degree that is at least 2 and the generator graph of $I$ is the graph of a disjoint union of trees and graphs with unique odd cycles then $I$ is an ideal of linear type.

  7. REE geochemical characteristics and depositional environment of the black shale-hosted Baiguoyuan Ag-V deposit in Xingshan, Hubei Province, China

    Institute of Scientific and Technical Information of China (English)

    YANG Boyong; HU Bin; BAO Zhengyu; ZHANG Zhaogan

    2011-01-01

    By means of techniques such as inductively coupled plasma-mass spectrometry (ICP-MS) and X-ray fluorescence spectrometry (XRF), REE geochemical characteristics and depositional environment of the black shales in Baiguoyuan Ag-V deposit, Xingshan, Hubei Province, were studied in this work. The black shales in a typical TC5 profile of Doushantuo Formation of upper Sinian period were obviously enriched in REE, especially in LREE. The REE patterns of the investigated samples normalized by Post Archean Australian Shale (PAAS) showed a flat or slight rightward inclination. The characteristic elements, their ratio and correlation diagrams showed that it should be hot-water deposit and the black shale in the study area was of a sedimentary origin. Redox sensitive metal elements pattern, trace elements index measurement in anoxic environment, Ce anomaly and δEu negative anomaly showed that the deposit environment of the black shales was a reducing and anoxic one and a slight change of the sea level could be identified. The samples relatively focused on the superimposed area of sedimentary rock and basalt in the diagram of La/Yb-ΣREE and La/Yb-Ce/La. So there might be accession of hot-water sedimentation during the period of the formation of the black rock series, mostly in normal terrigenous sedimentation with the participation of deep hot-water deposit.

  8. Geochemical and Geochronologic Investigations of Zircon-hosted Melt Inclusions in Rhyolites from the Mesoproterozoic Pea Ridge IOA-REE Deposit, St. Francois Mountains, Missouri

    Science.gov (United States)

    Watts, K. E.; Mercer, C. N.; Vazquez, J. A.

    2015-12-01

    Silicic volcanic and plutonic rocks of an eroded Mesoproterozoic caldera complex were intruded and replaced by iron ore, and cross-cut by REE-enriched breccia pipes (~12% total REO) to form the Pea Ridge iron-oxide-apatite-REE (IOA-REE) deposit. Igneous activity, iron ore formation, and REE mineralization overlapped in space and time, however the source of REEs and other metals (Fe, Cu, Au) integral to these economically important deposits remains unclear. Melt inclusions (MI) hosted in refractory zircon phenocrysts are used to constrain magmatic components and processes in the formation of the Pea Ridge deposit. Homogenized (1.4 kbar, 1000°C, 1 hr) MI in zircons from rhyolites ~600 ft (PR-91) and ~1200 ft (PR-12) laterally from the ore body were analyzed for major elements by EPMA and volatiles and trace elements (H2O, S, F, Cl, REEs, Rb, Sr, Y, Zr, Nb, U, Th) by SHRIMP-RG. Metals (including Cu, Au) will be measured in an upcoming SHRIMP-RG session. U-Pb ages, Ti and REE were determined by SHRIMP-RG for a subset of zircon spots adjacent to MI (1458 ± 18 Ma (PR-12); 1480 ± 45 Ma (PR-91)). MI glasses range from fresh and homogeneous dacite-rhyolite (65-75 wt% SiO2) to heterogeneous, patchy mixtures of K-spar and quartz (PR-12, 91), and more rarely mica, albite and/or anorthoclase (PR-91). MI are commonly attached to monazite and xenotime, particularly along re-entrants and zircon rims (PR-91). Fresh dacite-rhyolite glasses (PR-12) have moderate H2O (~2-2.5 wt%), Rb/Sr ratios (~8) and U (~5-7 ppm), and negative (chondrite-normalized) Eu anomalies (Eu ~0.4-0.7 ppm) (typical of rhyolites), whereas HREEs (Tb, Ho, Tm) are elevated (~2-3 ppm). Patchy K-spar and quartz inclusions (PR-12, 91) have flat LREE patterns, and positive anomalies in Tb, Ho, and Tm. One K-spar inclusion (PR-91) has a ~5-50 fold increase in HREEs (Tb, Dy, Ho, Er, Tm) and U (35 ppm) relative to other MI. U-Pb and REE analyses of its zircon host are not unusual (1484 ± 21 Ma); its irregular shape

  9. The effect of the water-to-rock ratio on REE distribution in hydrothermal fluids: An experimental study

    Science.gov (United States)

    Beermann, Oliver; Garbe-Schönberg, Dieter; Holzheid, Astrid

    2013-04-01

    High-temperature submarine MOR hydrothermalism creates high elemental fluxes into, and out of, oceanic lithosphere significantly affecting ocean chemistry. The Turtle Pits hydrothermal system discovered at 5° S on the slow-spreading Mid-Atlantic Ridge (MAR) in water depths of ~3000 m (~300 bar) emanates 'ultrahot' fluids > 400 ° C [1] with high concentrations of dissolved gases (e.g., H2), transition metals, and rare earth elements (REE). The normalised REE patterns of these 'ultrahot' fluids are uncommon as they exhibit depletions of LREE and no Eu-anomaly ('special' REE-signature in [2]), which is in contrast to the "typical" LREE enrichment and pronounced positive Eu-anomaly known from many MOR vent fluids observed world-wide [e.g., 3]. Although hydrothermal fluid REE-signatures may play a key role in understanding processes during water-rock interaction, only few experimental data have been published on REE distribution in seawater-like fluids reacted with rocks from the ocean crust [e.g., 4, 5]. Besides temperature, the seawater-to-rock ratio (w/r ratio) strongly affects water-rock reaction processes and, thus, has significant control on the fluid chemistry [e.g., 6, 7]. To understand how vent fluid REE-signatures are generated during water-rock interaction processes we designed a series of experiments reacting different fluid types with mineral assemblages from fresh, unaltered gabbro at 425 ° C and 400 bar using cold seal pressure vessels (CSPV). Mixtures of 125-500 μm-sized hand-picked plagioclase and clinopyroxene grains separated from unaltered gabbro reacted in gold capsules with 3.2 wt.% NaCl(aq) fluid (similar to seawater salinity), or with natural seawater. The w/r (mass) ratio ranged from 1 to 100 and the run durations were varied from 3 to 30 d in the NaCl(aq) experiments, and was 3 d in the seawater experiments. The reacted fluids were extracted after quenching and analysed by ICP-OES and ICP-MS. Only in the seawater experiments, the gabbro

  10. REE Geochemistry of Fluorite from the Maoniuping REE Deposit, Sichuan Province, China: Implications for the Source of Ore-forming Fluids

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Fluorite is one of the main gangue minerals in the Maoniuping REE deposit, Sichuan Province, China. Fluorite with different colors occurs not only within various orebodies, but also in wallrocks of the orefield. Based on REE geochemistry, fluorite in the orefieid can be classified as the LREE-rich, LREE-flat and LREE-depleted types. The three types of fluorite formed at different stages from the same hydrothermal fluid source, with the LREE-rich fluorite forming at the relatively early stage, the LREE-flat fluorite in the middle, and the LREE-depleted fluorite at the latest stage. Various lines of evidence demonstrate that the variation of the REE contents of fluorite shows no relation to the color. The mineralization of the Maoniuping REE deposit is associated spatially and temporally with carbonatite-syenite magmatism and the ore-forming fluids are mainly derived from carbonatite and syenite melts.

  11. REE characteristics and Pb, Sr and Nd isotopic compositions of steel plant emissions.

    Science.gov (United States)

    Geagea, M Lahd; Stille, P; Millet, M; Perrone, Th

    2007-02-01

    A comprehensive Pb-Sr-Nd isotope and REE tracer study of atmospheric trace metal pollution by a steel plant situated to the north of the urban communities of Strasbourg (France) and Kehl (Germany) has been performed using tree barks as biomonitors. The 206Pb/207Pb and 208Pb/207Pb isotopic ratios of the steel plant's filter dust are similar to values found in dust of waste incinerators. The 87Sr/86Sr ratio is similar to present-day ratios of Phanerozoic or Precambrian granitic rocks. The 143Nd/144Nd isotopic composition is very low and corresponds to an (Nd) value of -17.5. Such a low value is characteristic of old Precambrian granitic rocks and banded iron formations. Thus, this low (Nd) value might point to the origin of the iron necessary for the steel production. The fact, that this isotopic composition does not occur in crustal rocks of Western Central Europe makes the Nd isotope ratio a powerful tool to trace steel plants atmospheric emissions. The rare earth element (REE) distribution pattern of the steel plant's filter dust shows very specific fractionations like La and Nd enrichments which are traceable in tree barks over a distance of 4 km. The Pb, Sr and Nd isotope ratios not only enable the steel plant's emissions to be traced in a north-easterly direction, along the principal wind pathway but also enables the interference of this emission at 4 km NE from the steel plant with another atmospheric component originating from the Strasbourg Rhine harbour to be identified.

  12. Existing forms of REE in gold-bearing pyrite of the Jinshan gold deposit,Jiangxi Province,China

    Institute of Scientific and Technical Information of China (English)

    毛光周; 华仁民; 高剑峰; 李伟强; 赵葵东; 龙光明; 陆慧娟

    2009-01-01

    Rare earth element(REE) is widely used in various fields of geology.Study of the existing forms of REE in geological objects is a necessity for us to solve geological problems related with REE.This paper tried to make it clear the existing forms of REE in gold-bearing pyrite in Jinshan gold deposit by stepwise dissolution test with ICP-MS analysis.Results showed that content of REE in fluid-inclusions of gold-bearing pyrite was very low,which only took about 0.07%-0.70% of the ΣREE,and that of pyrite phase ...

  13. High-Pressure Rare Earth Disilicates REE2Si 2O 7( REE=Nd, Sm, Eu, Gd): Type K

    Science.gov (United States)

    Fleet, Michael E.; Liu, Xiaoyang

    2001-10-01

    A new structure type (K) is reported for the disilicates of Nd, Sm, Eu, and Gd made at high pressure. Crystals of type K were synthesized at 10 GPa, 1600-1700°C in an MA6/8 superpress and used for single-crystal X-ray structure study by Kappa CCD diffractometry at room temperature. Crystal data are: monoclinic, space group P21/n, Z=4; Nd2Si2O7-a=6.6658(2), b=6.7234(3), c=12.3975(6) Å, β=102.147(3)°, V=543.2 Å3, R=0.029, and Dx=5.584 g/cm3; Sm2Si2O7-a=6.6039(3), b=6.6849(3), c=12.3069(5) Å, β=102.489(3)°, V=530.4 Å3, R=0.038, and Dx=5.871 g/cm3; Eu2Si2O7-a=6.5777(3), b=6.6652(4), c=12.2668(8) Å, β=102.671(4)°, V=524.7 Å3, R=0.030, and Dx=5.976 g/cm3; Gd2Si2O7-a=6.5558(4), b=6.6469(4), c=12.2394(6) Å, β=102.844(3)°, V=520.0 Å3, R=0.026, and Dx=6.166 g/cm3. The type K structure is built from a diorthosilicate group [Si2O7] interconnected by REE3+ cations in eightfold coordination with oxygen. The bridging oxygen (Si-O-Si) bond angle of the diorthosilicate group of rare earth disilicates stable at 1 bar (types A to G) is related to spatial accommodation of the REE3+ cation and ranges from 130 to 135° in the light rare earth disilicates (types A, F, G) to 180° in Lu2Si2O7 (type C). Volume reduction in the high-pressure type K structure is achieved largely by closure of the Si-O-Si bond angle to 122.7-124.4°, through rigid body rotation of the two SiO4 tetrahedra. This also permits a marginal increase in the average coordination of the REE3+ cation.

  14. [Influence of PO4(3-) and citrate on REE accumulation and fractionation in wheat].

    Science.gov (United States)

    Yan, Jun-Cai; Liang, Tao; Zhang, Zi-Li; Ding, Shi-Ming

    2005-09-01

    This paper has studied the influence of phosphate (Pi, one of inorganic ligands) and citrate (Cit, one of organic ligands) on accumulation and fractionation of REEs in wheat based on aqueous culture, added with extraneous mixed REEs (MRE) and ICP-MS analysis technology. The results show that initial phosphate (Pi) solution of different levels followed by exposure to fixed-MRE solution has no significant effects on accumulation of the total concentrations of REEs (sigma REE) in the wheat roots, but it decrease the REE dramatically in the wheat leaves. Simultaneous culture of wheat with mixture of MRE and citrate solution caused obvious decreases of the sigma REE both in wheat roots and leaves. Compared to the control (no Pi or citrate was added), the distribution and fractionation characters of MRE had M-type tetrad effect and MREE enrichment in wheat roots, and W-type tetrad effect and HREE enrichment in wheat leaves. Different levels of Pi had no significant effects on the tetrad effect of MRE, but it notable increased the enrichment of HREE in wheat leaves. Added with citrate of different levels led the fractionation of REE decreasing gradually in wheat roots and leaves, as the concentration of citrate > or = 150 micromol x L(-1), light REE (LREE) enrichment both existed in the roots and leaves.

  15. Maximum Permissible Concentrations and Negligible Concentrations for Rare Earth Elements (REEs)

    NARCIS (Netherlands)

    Sneller FEC; Kalf DF; Weltje L; Wezel AP van; CSR

    2000-01-01

    In this report maximum permissible concentrations (MPCs) and negligible concentrations (NCs) are derived for Rare Earth Elements (REEs), which are also known as lanthanides. The REEs selected for derivation of environmental risk limits in this report are Yttrium (Y), Lanthanum (La), Cerium (Ce), Pra

  16. Mineralogy and geochemistry of trace metals and REE in volcanic massive sulfide host rocks, stream sediments, stream waters and acid mine drainage from the Lousal mine area (Iberian Pyrite Belt, Portugal)

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira da Silva, E. [GeoBioTec - GeoBiosciences, Technologies and Engineering Research Center, Departamento de Geociencias, Universidade de Aveiro, Campus de Santiago, 3810-193 Aveiro (Portugal)], E-mail: eafsilva@ua.pt; Bobos, I. [Departamento de Geologia, Faculdade de Ciencias da Universidade do Porto, Rua Campo Alegre 687 4169-007 Porto (Portugal); Xavier Matos, J. [Centro de Estudos Geologicos e Mineiros de Beja, Rua Frei Amador Arrais No. 39 r/c, Apartado 104, 7801-902 Beja (Portugal); Patinha, C.; Reis, A.P.; Cardoso Fonseca, E. [GeoBioTec - GeoBiosciences, Technologies and Engineering Research Center, Departamento de Geociencias, Universidade de Aveiro, Campus de Santiago, 3810-193 Aveiro (Portugal)

    2009-03-15

    Acid mine drainage represents a major source of water pollution in the Lousal area. The concentrations of trace metals and the rare earth elements (REE) in the host rocks, stream sediment, surface waters and acid mine drainage (AMD) associated with abandoned mine adits and tailings impoundments were determined, in order to fingerprint their sources and to understand their mobility and water-rock interaction. The results show that the Fe-SO{sub 4}-rich acid waters vary substantially in composition both spatially and seasonally. These waters include very low pH (mostly in the range 1.9-3.0), extreme SO{sub 4} concentrations (4635-20,070 mg L{sup -1}SO{sub 4}{sup 2-}), high metal contents (Fe, Al, Cu, Zn and Mn) and very high REE contents. The trace metal concentrations decrease downstream from the discharge points either due to precipitation of neoformed phases or to dilution. The North-American shale composite (NASC)-normalized patterns corresponding to sediment from one stream (Corona stream) show a flat tendency or are slightly enriched in light-REE (LREE). The NASC-normalized patterns corresponding to acidic mine waters show enrichment in the middle REE (MREE) with respect to the LREE and heavy REE (HREE). Moreover, the REE concentrations in acidic mine waters are 2 or 3 orders of magnitude higher than those of the surface waters. Changes of REE concentrations and variation of Eu anomaly show two spatially distinct patterns: (a) pond and spring waters with higher REE concentrations (ranging from 375 to 2870 {mu}g L{sup -1}), that records conspicuous negative Eu anomaly, and (b) seeps from tailings impoundments corresponding to lower REE concentrations than the first pattern (ranging from 350 to 1139 {mu}g L{sup -1}) with typically negative Eu anomaly. The stream water samples collected from the impacted stream during the spring show a low pH (2.8-3.1) and contain high concentrations of Fe and trace elements (up to 61 mg L{sup -1}). Also, temporal variations of

  17. Experimental mineral/liquid partition coefficients of the rare earth elements /REE/, Sc and Sr for perovskite, spinel and melilite

    Science.gov (United States)

    Nagasawa, H.; Schreiber, H. D.; Morris, R. V.

    1980-01-01

    Experimental determinations of the mineral/liquid partition coefficients of REE (La, Sm, Eu, Gd, Tb, Yb and Lu), Sc and Sr are reported for the minerals perovskite, spinel and melilite in synthetic systems. Perovskite concentrates light REE with respect to the residual liquid but shows no preference for heavy REE. Spinel greatly discriminates against the incorporation of REE, especially light REE, into its crystal structure. The partition of REE into melilite from a silicate liquid is quite dependent upon both the bulk melt and melilite solid-solution (gehlenite and akermanite components) compositions. As such, melilite can be enriched in REE or will reject REE with corresponding strong negative or strong positive Eu anomalies, respectively.

  18. Chemical Compositions of Calcites in Carbonatites from Panxi Region Implications for Genesis of Carbonatites and Associated REE Deposits

    Institute of Scientific and Technical Information of China (English)

    XU Cheng; HUANG Zhi-long

    2008-01-01

    @@ The Panxi region is important REE mineralization belt in China. Chemical compositions of calcites in carbon-atites from Daluxiang and Maoniuping REE deposits are analyzed by LA-ICPMS. At Maoniuping the reserve of REE2O3 is estimated to be more than 1.45 million tons.

  19. REE Geochemical Evolution and Its Significance of Early Precambrian Metamorphic Terrain,Wuyang,Henan

    Institute of Scientific and Technical Information of China (English)

    陈衍景; 富士谷; 等

    1992-01-01

    The supracrustal rocks of the Wuyang metamorphic terrain are divided into the Zhao anzhuang,Tieshanmiao and Yangshuwan Formations.These three Formations were dated at 3000-2550Ma,2550-2300Ma and 2300-2200Ma,respectively.∑REE and La/Yb)n of the Zhao anzhuang Formation volcanic rocks are obviously higher than those of the Tiesanmiao Formation equivalents,suggesting a sedimentary gap(2550 Ma boundary)between these two formations,The Zhao'anzhuang Formation is older than the Tieshanmiao Formation.The sediments of these two Formations show no obvious differences in REE and are generally characterized by low ∑REE and positive Eu anomalies.On the contrary,the sediments of the Yangshuwan Formation are characterized by high ∑REE and negative Eu anomalies.Detailed discussions demonstrate that the Yangshuwan Formation was deposited in an oxidizing environment whereas the other two formations were formed in a reducing environment.At the end of the evolution of the Tieshanmiao Formation about 2300 Ma ago,the sedimentary environment was transformed from reducing to oxidizing .On the basis of the SHAB (soft/hard acid and base)theory,an oxidation-reduction model for sedimentary REE evolution has been established .It is proposed that the mantle tends to become gradually depleted in REE.especially in LREE,and the indices ∑REE and La/Yb) n of mantle-dervived volcanic rocks also tend to become lower and lower.

  20. The giant Bayan Obo REE-Nb-Fe deposit, China: Controversy and ore genesis

    Directory of Open Access Journals (Sweden)

    Hong-Rui Fan

    2016-05-01

    Full Text Available Bayan Obo ore deposit is the largest rare-earth element (REE resource, and the second largest niobium (Nb resource in the world. Due to the complicated element/mineral compositions and involving several geological events, the REE enrichment mechanism and genesis of this giant deposit still remains intense debated. The deposit is hosted in the massive dolomite, and nearly one hundred carbonatite dykes occur in the vicinity of the deposit. The carbonatite dykes can be divided into three types from early to late: dolomite, co-existing dolomite-calcite and calcite type, corresponding to different evolutionary stages of carbonatite magmatism based on the REE and trace element data. The latter always has higher REE content. The origin of the ore-hosting dolomite at Bayan Obo has been addressed in various models, ranging from a normal sedimentary carbonate rocks to volcano-sedimentary sequence, and a large carbonatitic intrusion. More geochemical evidences show that the coarse-grained dolomite represents a Mesoproterozoic carbonatite pluton and the fine-grained dolomite resulted from the extensive REE mineralization and modification of the coarse-grained variety. The ore bodies, distributed along an E–W striking belt, occur as large lenses and underwent more intense fluoritization and fenitization. The first episode mineralization is characterized by disseminated mineralization in the dolomite. The second or main-episode is banded and/or massive mineralization, cut by the third episode consisting of aegirine-rich veins. Various dating methods gave different mineralization ages at Bayan Obo, resulting in long and hot debates. Compilation of available data suggests that the mineralization is rather variable with two peaks at ∼1400 and 440 Ma. The early mineralization peak closes in time to the intrusion of the carbonatite dykes. A significant thermal event at ca. 440 Ma resulted in the formation of late-stage veins with coarse crystals of REE

  1. Cancer vaccines: looking to the future. Interview by Jenaid Rees.

    Science.gov (United States)

    Apostolopoulos, Vasso

    2013-10-01

    Interview by Jenaid Rees (Commissioning Editor) Vasso Apostolopoulos has been working in the field of cancer vaccines since 1991, and human clinical trials on her work have been conducted since 1994. Her work has been at the forefront of scientific research into the development of a vaccine for cancer and she has received over 90 awards and honours in recognition of her achievements. Some notable awards include, the Premier's Award for medical research, was named Young Australian of the Year (Victoria), recipient of the Channel 10/Herald Sun Young Achiever of the Year Award as well as being awarded the Order of Brigadier General of the Phoenix Battalion by the Greek President. In 1998 Apostolopoulos received the NHMRC CJ Martin Research Fellowship and worked at the Scripps Research Institute in California, USA, for 3.5 years and returned to the Austin Research Institute (VIC, Australia), and headed the Immunology and Vaccine Laboratory receiving the NHMRC RD Wright Fellowship. Upon her return to Australia, Apostolopoulos received the Victorian Tall Poppy Award, the Bodossaki Foundation Academic Prize, was inducted into the Victorian Honour roll of Women, was a torchbearer for the Melbourne leg of the International Athens 2004 Olympic Torch Relay, was named Woman of the Year, and is an Australia Day Ambassador. Her contribution into cancer research, vaccines and immunology has been extensive - publishing over 200 scientific papers and books, an inventor on 14 patents and collaborates with over 50 national and international Research Institutes and Universities. Her current research interests are in the development of new improved cancer vaccines and new modes of antigen delivery for immune stimulation. She is also interested in chronic diseases treatment and prevention through immunotherapy. She serves on the Editorial Board for Expert Review of Vaccines.

  2. Observation results of relativistic electrons detected by Fengyun-1 satellite and analysis of relativistic electron enhancement (REE) events

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The space particle component detector on Fengyun-1 satellite which works at the sun-synchronous orbit of about 870 km altitude has detected relativistic electrons for a long time. In comparison with the SAMPEX satellite observations during 1999 -2004, the relativistic electron data from Fengyun-1 satellite from June 1999 to 2005 are used to analyze the relativistic electron enhancement (REE) events at the low earth orbit, and the possible correlation among REE events at the low earth orbit, high-speed solar wind and geomagnetic storms is discussed. The statistical result presents that 45 REE events are found in total during this time period, and the strong REE events with the maximum daily average flux > 400 cm?2·sr?1·s?1 occur mostly during the transition period from solar maximum to solar minimum. Among these 45 REE events, four strong REE events last a longer time period from 26- to 51-day and correlate closely with high speed solar wind and strong geo- magnetic storms. Meanwhile, several strong geomagnetic storms occur continu- ously before these REE events, and these continuous geomagnetic storms would be an important factor causing these long-lasting strong REE events. The correlation analysis for overall 45 events indicates that the strength of the REE events corre- lates with the solar wind speed and the strength of the geomagnetic storm, and the correlation for strong REE events is much stronger than that for weak REE events.

  3. A selected thermodynamic database for REE to be used in HLNW performance assessment exercises

    Energy Technology Data Exchange (ETDEWEB)

    Spahiu, K.; Bruno, J. [MBT Tecnologia Ambiental, Cerdanyola (Spain)

    1995-01-01

    A selected thermodynamic database for the Rare Earth Elements (REE) to be used in the safety assessment of high-level nuclear waste deposition has been compiled. Thermodynamic data for the aqueous species of the REE with the most important ligands relevant for granitic groundwater conditions have been selected and validated. The dominant soluble species under repository conditions are the carbonate complexes of REE. The solubilities of the oxides, hydroxides, carbonates, hydroxycarbonates, phosphates and other important solids have been selected and validated. Solubilities and solubility limiting solids in repository conditions have been estimated with the selected database. At the initial stages of fuel dissolution, the UO{sub 2} matrix dissolution will determine the concentrations of REE. Later on, solid phosphates, hydroxycarbonates and carbonates may limit their solubility. Recommendations for further studies on important systems in repository conditions have been presented. 136 refs, 13 figs, 16 tabs.

  4. Determining Foundry Area of Bronze Vessel Using REE in Clay Mould Residues

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The composition of casting clay core might provide clue to the foundry area of the bronze vessels. REE analysis of the residual clay mould was conducted by inductively coupled plasma atomic emission spectrometer (ICP-AES). Results reveal that characteristic of REE of clay mould from different region is dissimilar. It is feasible to restrict the possible foundry area of the bronze vessels on the basis of analysis of REE of clay mould residues on the bronzes. Meanwhile, this paper attempts to determine the foundry area of the bronze vessels unearthed at Jiuliandun tombs of Chu State, dated back to Warring States Period, in Zaoyang City, Hubei Province, and at Zuozhong cemetery, Spring and Autumn Period, in Jingmen City, Hubei Province. REE of clay core provides information on the foundry area of bronze vessels.

  5. Using REE Tracers to Measure Sheet Erosion Changing to Rill Erosion

    Institute of Scientific and Technical Information of China (English)

    宋炜; 刘普灵; 杨明义; 薛亚洲

    2003-01-01

    Rare earth element(REE) tracer method was used to study sheet erosion changing to rill erosion on slope land. By placing different REE on different soil depth across a slope in an indoor plot, two simulated rainfalls were applied to study the change of erosion type and the rill erosion process. The results indicate that the main erosion type is sheet erosion at the beginning of the rainfalls, and serious erosion happens after rill erosion appears. Accumulated sheet and rill erosion amount increases with the rainfalls time. The percentage of sheet erosion amount decreases and rill erosion percentage increases with time. At the end of the rainfalls, the total rill erosion amounts are 4.3 and 5 times more than sheet erosion. In this paper, a new REE tracer method was used to quantitatively distinguish sheet and rill erosion amount. The new REE tracer method should be useful to future studying of erosion processes on slope lands.

  6. The impact of transport processes on rare earth element patterns in marine authigenic and biogenic phosphates

    Science.gov (United States)

    Auer, Gerald; Reuter, Markus; Hauzenberger, Christoph A.; Piller, Werner E.

    2017-04-01

    Rare earth elements (REEs) are commonly used proxies to reconstruct water chemistry and oxygen saturation during the formation of authigenic and biogenic phosphates in marine environments. In the modern ocean REEs exhibit a distinct pattern with enrichment of heavy REEs and strong depletion in cerium (Ce). The wide range of REE enrichment patterns found in ancient marine phosphates lead to the proposition that water chemistry has been very different in the Earth's past. However, both early and late diagenesis are known to affect REE signatures in phosphates altering primary marine signals. Herein we present a dataset of REE signatures in 38 grain specific LA-ICP-MS measurements of isolated phosphate and carbonate grains in three discrete rock samples. The phosphates mainly consist of authigenic phosphates and phosphatized microfossils that formed in a microbially mediated micro-milieu. In addition, isolated biogenic and reworked phosphatic grains are also present. The phosphates are emplaced in bioclastic grain- to packstones deposited on a carbonate ramp setting in the central Mediterranean Sea during the middle Miocene Monterey event. The results reveal markedly different REE patterns (normalized to the Post Archean Australian Shale standard) in terms of total enrichment and pattern shape. Analyses of REE diagenesis proxies show that diagenetic alteration affected the samples only to a minor degree. Grain shape and REE patterns together indicate that authigenic, biogenic and reworked phosphates have distinct REE patterns irrespective of the sample. Our study shows that while REE patterns in phosphates do reflect water chemistry during authigenesis, they are often already heavily altered during reworking, a process, which can occur in geologically negligible timespans. REE patterns are therefore more likely to reflect complex enrichment processes after their formation. Similarities in the REE patterns of reworked and biogenic phosphate further suggest that the

  7. REE characteristics and genesis of alkaline-rich porphyry, Yunnan Province

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The Yunnan Himalayan alkaline-rich porphyry occurs as a compound rockbelt and consists of calca-alkalic, alkaline and peralkaline intrusions. Its origin is in debate. The paper deals with its origin by studying rock′s REE and Sr isotope. Although the rocks are different in their REE contents varying from 77.53 μg/g to 1 798.3 μg/g, they have very similar features in REE parameters. On the triangalar diagram of REEs, the sample dots are concentrated on the end area of light REEs, representing a product of low-degree melting of upper mantle or lower crust materials. The initial 87Sr/86Sr values of rocks vary between 0.706 4 and 0.709 8, showing a feature of mantle-crust mixed source. Moreover, REEs show a logarithmic linear positive correlation between them. This type of correlation strongly supports the fractional-partial melting model. The result of geochemistry inversion shows that the source rock of alkaline-rich porphyry is plagioclase-bearing harzburgite and of mantle-crust mixed type. At the early state of melting, some crust components of the source rock were partially melted into intermediate-acidic magma; with the crust components consumed, the magma evolved to basic.

  8. Seawater-like trace element signatures (REE + Y) of Eoarchaean chemical sedimentary rocks from southern West Greenland, and their corruption during high-grade metamorphism

    Science.gov (United States)

    Friend, C. R. L.; Nutman, A. P.; Bennett, V. C.; Norman, M. D.

    2008-02-01

    Modern chemical sediments display a distinctive rare earth element + yttrium (REE + Y) pattern involving depleted LREE, positive La/La*SN, Eu/Eu*SN, and YSN anomalies (SN = shale normalised) that is related to precipitation from circumneutral to high pH waters with solution complexation of the REEs dominated by carbonate ions. This is often interpreted as reflecting precipitation from surface waters (usually marine). The oldest broadly accepted chemical sediments are c. 3,700 Ma amphibolite facies banded iron-formation (BIF) units in the Isua supracrustal belt, Greenland. Isua BIFs, including the BIF international reference material IF-G are generally considered to be seawater precipitates, and display these REE + Y patterns (Bolhar et al. in Earth Planet Sci Lett 222:43 60, 2004). Greenland Eoarchaean BIF metamorphosed up to granulite facies from several localities in the vicinity of Akilia (island), display REE + Y patterns identical to Isua BIF, consistent with an origin by chemical sedimentation from seawater and a paucity of clastic input. Furthermore, the much-debated magnetite-bearing siliceous unit of “earliest life” rocks (sample G91/26) from Akilia has the same REE + Y pattern. This suggests that sample G91/26 is also a chemical sediment, contrary to previous assertions (Bolhar et al. in Earth Planet Sci Lett 222:43 60, 2004), and including suggestions that the Akilia unit containing G91/26 consists entirely of silica-penetrated, metasomatised, mafic rock (Fedo and Whitehouse 2002a). Integration of our trace element data with those of Bolhar et al. (Earth Planet Sci Lett 222:43 60, 2004) demonstrates that Eoarchaean siliceous rocks in Greenland, with ages from 3.6 to 3.85 Ga, have diverse trace element signatures. There are now geographically-dispersed, widespread examples with Isua BIF-like REE + Y signatures, that are interpreted as chemically unaltered, albeit metamorphosed, chemical sediments. Other samples retain remnants of LREE depletion but

  9. Rare earth elements (REEs) in the tropical South Atlantic and quantitative deconvolution of their non-conservative behavior

    Science.gov (United States)

    Zheng, Xin-Yuan; Plancherel, Yves; Saito, Mak A.; Scott, Peter M.; Henderson, Gideon M.

    2016-03-01

    This study presents new concentration measurements of dissolved rare earth elements (dREEs) along a full-depth east-west section across the tropical South Atlantic (∼12°S), and uses these data to investigate the oceanic cycling of the REEs. Enrichment of dREEs, associated with the redox cycling of Fe-Mn oxides, is observed in the oxygen minimum zone (OMZ) off the African shelf. For deeper-waters, a multi-parameter mixing model was developed to deconvolve the relative importance of physical transport (i.e., water mass mixing) from biogeochemical controls on the dREE distribution in the deep Atlantic. This approach enables chemical processes involved in REE cycling, not apparent from the measurements alone, to be distinguished and quantified. Results show that the measured dREE concentrations below ∼1000 m are dominantly controlled (>75%) by preformed REE concentrations resulting from water mass mixing. This result indicates that the linear correlation between dREEs and dissolved Si observed in Atlantic deep waters results from the dominantly conservative behavior of these tracers, rather than from similar chemical processes influencing both dREEs and Si. Minor addition of dREEs (∼10% of dNd and ∼5% of dYb) is observed in the deep (>∼4000 m) Brazil Basin, resulting from either remineralization of particles in-situ or along the flow path. Greater addition of dREEs (up to 25% for dNd and 20% for dYb) is found at ∼1500 m and below ∼4000 m in the Angola Basin near the African continental margin. Cerium anomalies suggest that different sources are responsible for these dREE addition plumes. The 1500 m excess is most likely attributed to dREE release from Fe oxides, whereas the 4000 m excess may be due to remineralization of calcite. Higher particulate fluxes and a more sluggish ocean circulation in the Angola Basin may explain why the dREE excesses in this basin are significantly higher than that observed in the Brazil Basin. Hydrothermal venting over the

  10. Accumulation of Rare Earth Elements in Spinach and Soil under Condition of Using REE and Acid Rain Stress

    Institute of Scientific and Technical Information of China (English)

    严重玲; 洪业汤; 林鹏; 王世杰; 李心清; 梁洁

    2002-01-01

    The content and distribution characteristics of REE in spinach and soil under using REE and acid rain stress were studied by pot experiments. The results show that the content of REE is 0.527~0.696 (μgg-1) in the above-ground portion of spinach, 2.668~3.003 (μg*g-1) in the under-ground portion of spinach and 229.09~250.30 (μg*g-1) in the soil. With the acidity of acid rain increasing, the leaching of REE in plants and soil is strengthened and the amount of REE reduces with decreasing of pH value. After REE are used, though plants show the selective absorption to Ce group elements (especially spraying on leaves), regardless under acid rain stress or using REE or not, the distribution model of REE in the above-ground and under-ground portion of plants is basically the same with the control. Plants also follow the Oddo-Harkins rule of the REE of distribution abundance, light rare earth elements is enriched, the minus of Eu is abnormal and admeasure of Ce is a rich model. The results show that REE in plants mainly come from soil and are affected by it.

  11. Petrography and Geochemistry (Trace, Ree and Pge of Pedda Cherlo Palle Gabbro-Diorite Pluton, Prakasam Igneous Province, Andhra Pradesh, India

    Directory of Open Access Journals (Sweden)

    Subramanyam K.S.V.

    2015-09-01

    Full Text Available Prakasam Igneous Province (PIP is an important geological domain in the Eastern Dharwar Craton (EDC, found in the junction zone between the EDC and Eastern Ghat Mobile Belt (EGMB. The Pedda Cherlo Palle (PCP gabbros are massive, leucocratic-mesocractic, and show cumulus textures with minerals plagioclase, cpx, and amphiboles. Compositionally, plagioclase is a labradorite-bytownite, cpx is diopside to augite, olivines are hyalosiderites and amphiboles are magnesiohornblendes. PCP gabbros have normal SiO2, high Al2O3, moderate to high TiO2, Na2O and medium Fe2O3, so, classified as subalkaline tholeiitic gabbros. Fractionated rare earth element (REE patterns, high abundance of large ion lithofile elements (LILE and transitional metals coupled with light REE (LREE relative enrichment over heavy REE (HREE and Nb are characteristics of partial melting of depleted mantle and melts that have undergone fractional crystalisation. These partial melts are enriched in LREE and LILE, due to the addition of slab derived sediment and fluids. PCP gabbros contain low abundance (5.1 to 24.6 ng/g of platinum group elements (PGE, and show an increase in the order Ir>Os>Pt>Ru»Pd>Rh. We propose that the subduction related intraoceanic island arc might have accreted to the southeastern margin of India to the east of Cuddapah basin in a collisional regime that took place during Ur to Rodinia amalgamations.

  12. Using Rare Earth Element (REE) tracers to identify preferential micro-sites of post-fire aeolian erosion

    Science.gov (United States)

    Van Pelt, R.; Zobeck, T. M.; Barnes, M. A.; Baddock, M.; D'Odorico, P.

    2011-12-01

    abrader was added to the wind tunnel flow and a second test of 10 minutes with abrader added to the flow. At the end of the first four tests, the wind tunnel cooling system broke and due to the extent of necessary repairs, the last two plots were tested two weeks later. Three paired aeolian sediment samples were collected for each plot tested. The results indicated that in desert grassland, a disproportionate amount of the post-fire sediment is entrained from areas under grass clumps and in grassland-shrubland ecotones, the soil under shrubs is the primary source of entrained sediment followed by areas under grass clumps. The bare surfaces between vegetation produced the least sediment. REEs appear to be a powerful tool for investigating spatial patterns of aeolian processes.

  13. Microbial mobilization of rare earth elements (REE from mineral solids—A mini review

    Directory of Open Access Journals (Sweden)

    Fabienne Barmettler

    2016-06-01

    Full Text Available In the light of an expected supply shortage of rare earth elements (REE measures have to be undertaken for an efficient use in all kinds of technical, medical, and agricultural applications as well as—in particular—in REE recycling from post-use goods and waste materials. Biologically- based methods might offer an alternative and supplement to physico-chemical techniques for REE recovery and recycling. A wide variety of physiologically distinct microbial groups have the potential to be applied for REE bioleaching form solid matrices. This source is largely untapped until today. Depending of the type of organism, the technical process (including a series of influencing factors, the solid to be treated, and the target element, leaching efficiencies of 80 to 90% can be achieved. Bioleaching of REEs can help in reducing the supply risk and market dependency. Additionally, the application of bioleaching techniques for the treatment of solid wastes might contribute to the conversion towards a more sustainable and environmental friendly economy.

  14. Th, U, REE Backgrounds and Phytoavailability in Soils of the Padanian Plain (Northern Italy

    Directory of Open Access Journals (Sweden)

    Dario Di Giuseppe

    2014-12-01

    Full Text Available In this contribution we present ICP-MS analyses carried out on agricultural soils from the eastern-most part of the Padanian plain (Ferrara Province and on the related crop products. The aim is to provide, for the first time, backgrounds for some trace elements such as rare earth elements (REE, thorium (Th, uranium (U and to understand the related phytoavailability. In particular, detailed analyses have been done on Sorghum Vulgare plants, analyzing distinct plant parts in different vegetative periods. Results indicate that a REE concentration in plant tissues is always lower than in the related soils, precluding the occurrence of bioaccumulation and b no preferential elemental uptake and REE fractionation. In this light, the observed soil/plant relationships could be used in the definition of markers of territoriality (provenance fingerprint for agricultural products.

  15. Hydrothermal REE and Zr Ore Forming Processes in Peralkaline Granitic Systems

    Science.gov (United States)

    Gysi, A. P.

    2015-12-01

    Anorogenic peralkaline igneous systems display extreme enrichment of REE and Zr with a hydrothermal overprint leading to post-magmatic metal mobilization. Strange Lake in Canada, for example, is a mid-Proterozoic peralkaline granitic intrusion and host to a world-class REE-Zr deposit with >50 Mt ore (>1.5 wt.% REE and >3 wt.% Zr). In contrast to porphyry systems, peralkaline systems are poorly understood and hydrothermal metal mobilization models are only in the early stage of their development. This is partly due to the paucity of thermodynamic data for REE-bearing minerals and aqueous species, and the complexity of the hydrothermal fluids (enrichment of F, P and Cl), which make it difficult to develop thermodynamic models of metal partitioning. This study aims to show the link between alteration stages and metal mobilization using Strange Lake as a natural laboratory and combine these observations with numerical modeling. Four types of alteration were recognized at Strange Lake: i) alkali (i.e. K and Na) metasomatism related to interaction with NaCl-bearing orthomagmatic fluids, ii) acidic alteration by HCl-HF-bearing fluids originating from the pegmatites followed by iii) aegirinization of the border of the pegmatites and surrounding granites and by iv) pervasive Ca-F-metasomatism. The acidic alteration accounts for most of the hydrothermal metal mobilization in and outward from the pegmatites, whereas the Ca-F-metasomatism led to metal deposition and resulted from interaction of an acidic F-rich fluid with a Ca-bearing fluid. Numerical simulations of fluid-rock reactions with saline HCl-HF-bearing fluids at 400 °C to 250 °C indicate that temperature, availability of F/Cl and pH limit the mobility of Zr and REE. Fluids with pH hydrothermal metal mobilization in peralkaline granitic systems is the formation of a fluid-buffered subsystem providing the acids and ligands required for REE and Zr mobilization.

  16. Rare earth elements (REEs): effects on germination and growth of selected crop and native plant species.

    Science.gov (United States)

    Thomas, Philippe J; Carpenter, David; Boutin, Céline; Allison, Jane E

    2014-02-01

    The phytotoxicity of rare earth elements (REEs) is still poorly understood. The exposure-response relationships of three native Canadian plant species (common milkweed, Asclepias syriaca L., showy ticktrefoil, Desmodium canadense (L.) DC. and switchgrass, Panicum virgatum L.) and two commonly used crop species (radish, Raphanus sativus L., and tomato, Solanum lycopersicum L.) to the REEs lanthanum (La), yttrium (Y) and cerium (Ce) were tested. In separate experiments, seven to eight doses of each element were added to the soil prior to sowing seeds. Effects of REE dose on germination were established through measures of total percent germination and speed of germination; effects on growth were established through determination of above ground biomass. Ce was also tested at two pH levels and plant tissue analysis was conducted on pooled samples. Effects on germination were mostly observed with Ce at low pH. However, effects on growth were more pronounced, with detectable inhibition concentrations causing 10% and 25% reductions in biomass for the two native forb species (A. syriaca and D. canadense) with all REEs and on all species tested with Ce in both soil pH treatments. Concentration of Ce in aboveground biomass was lower than root Ce content, and followed the dose-response trend. From values measured in natural soils around the world, our results continue to support the notion that REEs are of limited toxicity and not considered extremely hazardous to the environment. However, in areas where REE contamination is likely, the slow accumulation of these elements in the environment could become problematic.

  17. Ciudad Real i Puertollano. Àrees funcionals urbanes (FUA) i policentrisme a Castellala Manxa (Espanya)

    OpenAIRE

    Cañizares Ruiz, María del Carmen; Martínez Sánchez-Mateos, Héctor Samuel

    2014-01-01

    Les àrees funcionals urbanes (FUA) de Ciudad Real i de Puertollano s’estructuren entorn de totes dues ciutats, funcionalment diferents, però que mantenen relacions cada cop més intenses en el sector sud-oest de la regió de Castella-la Manxa, a la província de Ciudad Real. Aquestes interrelacions es fonamenten en les infraestructures de comunicació, principalment la línia de ferrocarril d’alta velocitat. El present article caracteritza totes dues àrees funcionals i determina les relacions entr...

  18. 相山铀矿田山南矿区稀土元素特征及其地质意义%REE Characteristics of Shannan Deposit District in Xiangshan Uranium Orefield and Its Geological Significance

    Institute of Scientific and Technical Information of China (English)

    邵飞; 许健俊; 何晓梅; 何丹丹; 刘春月

    2012-01-01

    REE geochemical characteristics of rock and ore are studied in Shannan deposit district of Xiangshan Uranium orefield. The mean values of ΣREE of both basement schist and volcanic rock are approximately equal. Σ REE gradually increases from rock, common ore to bonanza. REE distribution patterns of rocks are right declined type to light REE. REE distribution patterns of volcanic rock series are parallel and concordant, the volcanic rock series are homologous, and products of pulsating events of same magma chamber. Eu depletes remarkably in volcanic rock series and ores. On its way to surface, magma underwent high fractionation and crystallization , based on feature of REE component ratio, triangle diagram of light medium and heavy REE, and diagram of LREE/HREE-(Eu/ΣREE) × 100. U and REE enriched in hydrothermal solution of post-magmatism to provide substances for uranium metallogenesis. Both diagenesis of volcanic rock series and uranium metallogenesis in the mining district are constrained by volcano-magmatism. Metallogenic fluid is rich in volatiles, such as F, Cl, CO2 etc. Metallogenic substances are unloaded in reduction environment. Metallogenic temperature is probably less than 250 ℃. Genesis of bonanza is more complicated and likely superimposed by multi-metallogenesis.%对相山铀矿田山南矿区围岩、矿石稀土元素地球化学特征进行了研究.矿区基底片岩∑REE平均值与火山岩系岩石∑REE平均值大致相当,自围岩、普通矿石到富矿石,∑REE不断增高.围岩稀土元素配分模式均呈轻稀土富集的右倾型,火山岩系岩石稀土元素配分模式彼此平行一致,火山岩系具同源性,是同一岩浆房脉动事件的产物.火山岩系围岩及矿石Eu亏损明显,结合稀土组分比值特征及岩、矿石轻、中、重稀土三角图解和LREE/HREE-( Eu/∑ REE)×100图解特征,表明火山岩浆在通向地表途中受到高度分馏结晶作用,U及REE富集于岩浆期后热液,为铀

  19. Observation results of relativistic electrons detected by Fengyun-1 satellite and analysis of relativistic electron enhancement (REE) events

    Institute of Scientific and Technical Information of China (English)

    YANG XiaoChao; WANG Shidin

    2008-01-01

    The space particle component detector on Fengyun-1 satellite which works at the sun-synchronous orbit of about 870 km altitude has detected relativistic electrons for a long time.In comparison with the SAMPEX satellite observations during 1999--2004,the relativistic electron data from Fengyun-1 satellite from June 1999 to 2005 are used to analyze the relativistic electron enhancement (REE) events at the low earth orbit,and the possible correlation among REE events at the low earth orbit,high-speed solar wind and geomagnetic storms is discussed.The statistical result presents that 45 REE events are found in total during this time period,and the strong REE events with the maximum daily average flux > 400 cm-2.sr-1.s-1 occur mostly during the transition period from solar maximum to solar minimum.Among these 45 REE events,four strong REE events last a longer time period from 26- to 51-day and correlate closely with high speed solar wind and strong geo-magnetic storms.Meanwhile,several strong geomagnetic storms occur continu-ously before these REE events,and these continuous geomagnetic storms would be an important factor causing these long-lasting strong REE events.The correlation analysis for overall 45 events indicates that the strength of the REE events corre-lates with the solar wind speed and the strength of the geomagnetic storm,and the correlation for strong REE events is much stronger than that for weak REE events.

  20. Tracing thermal aquifers of El Chichón volcano-hydrothermal system (México) with 87Sr/ 86Sr, Ca/Sr and REE

    Science.gov (United States)

    Peiffer, L.; Taran, Y. A.; Lounejeva, E.; Solís-Pichardo, G.; Rouwet, D.; Bernard-Romero, R. A.

    2011-08-01

    The volcano-hydrothermal system of El Chichón volcano, Chiapas, Mexico, is characterized by numerous thermal manifestations including an acid lake, steam vents and boiling springs in the crater and acid and neutral hot springs and steaming ground on the flanks. Previous research on major element chemistry reveals that thermal waters of El Chichón can be divided in two groups: (1) neutral waters discharging in the crater and southern slopes of the volcano with chloride content ranging from 1500 to 2200 mg/l and (2) acid-to-neutral waters with Cl up to 12,000 mg/l discharging at the western slopes. Our work supports the concept that each group of waters is derived from a separate aquifer (Aq. 1 and Aq. 2). In this study we apply Sr isotopes, Ca/Sr ratios and REE abundances along with the major and trace element water chemistry in order to discriminate and characterize these two aquifers. Waters derived from Aq. 1 are characterized by 87Sr/ 86Sr ratios ranging from 0.70407 to 0.70419, while Sr concentrations range from 0.1 to 4 mg/l and Ca/Sr weight ratios from 90 to 180, close to average values for the erupted rocks. Waters derived from Aq. 2 have 87Sr/ 86Sr between 0.70531 and 0.70542, high Sr concentrations up to 80 mg/l, and Ca/Sr ratio of 17-28. Aquifer 1 is most probably shallow, composed of volcanic rocks and situated beneath the crater, within the volcano edifice. Aquifer 2 may be situated at greater depth in sedimentary rocks and by some way connected to the regional oil-gas field brines. The relative water output (l/s) from both aquifers can be estimated as Aq. 1/Aq. 2-30. Both aquifers are not distinguishable by their REE patterns. The total concentration of REE, however, strongly depends on the acidity. All neutral waters including high-salinity waters from Aq. 2 have very low total REE concentrations (hydrothermal vapors, REE distribution in thermal waters reflects the dissolution of volcanic rocks close to the surface or lake sediments as is the case

  1. Mineral chemistry of Rare Earth Element (REE) mineralization, Browns Ranges, Western Australia

    Science.gov (United States)

    Cook, Nigel J.; Ciobanu, Cristiana L.; O'Rielly, Daniel; Wilson, Robin; Das, Kevin; Wade, Benjamin

    2013-07-01

    ‘Green energy futures’ are driving unprecedented demand for Rare Earth Elements (REE), underpinning significant exploration activity worldwide. Understanding how economic REE concentrations form is critical for development of exploration models. REE mineralisation in the Browns Ranges, Gordon Downs Region, Western Australia, comprises xenotime-dominant mineralisation hosted within Archaean to Palaeoproterozoic metasedimentary units (Browns Range Metamorphics). Mineralogical, petrographic and mineral-chemical investigation, including trace element analysis by Laser-Ablation Inductively-Coupled Plasma Mass Spectroscopy, gives insights into the mineralogical distribution and partitioning of REE, and also provides evidence for the genetic evolution of the Browns Range REE mineralisation via a succession of hydrothermal processes. Two main REE-bearing minerals are identified: xenotime [(Y,REE)PO4], which is HREE selective; and subordinate florencite [(REEAl3(PO4)2(OH)6] which is LREE selective. Two morphological generations of xenotime are recognised; compositions are however consistent. Xenotime contains Dy (up to 6.5 wt.%), Er (up to 4.35 wt.%), Gd (up to 7.56 wt.%), Yb (up to 4.65 wt.%) and Y (up to 43.3 wt.%). Laser Ablation ICP-MS element mapping revealed a subtle compositional zoning in some xenotime grains. LREE appear concentrated in the grain cores or closest to the initial point of growth whereas HREE, particularly Tm, Yb and Lu, are highest at the outer margins of the grains. The HREE enrichment at the outer margins is mimicked by As, Sc, V, Sr, U, Th and radiogenic Pb. Florencite is commonly zoned and contains Ce (up to 11.54 wt.%), Nd (up to 10.05 wt.%) and La (up to 5.40 wt.%) and is also notably enriched in Sr (up to 11.63 wt.%) and Ca. Zircon (which is not a significant contributor of REEs overall due to its low abundance in the rocks) is also enriched in REE (up to 13 wt.% ΣREE) and is the principal host of Sc (up to 0.8 wt.%). Early, coarse

  2. Regional Variations of REE Patterns in Sediments from Active Plate Boundaries

    DEFF Research Database (Denmark)

    Kunzendorf, H.; Stoffers, P.; Gwozdz, R.

    1988-01-01

    About 150 sediment samples from mid-ocean ridges (East Pacific Rise, Central Indian Ocean Ridge, Carlsberg Ridge and the Red Sea) and from a back-arc spreading environment (Lau Basin) were analyzed by instrumental neutron activation. A ratio method for rare-earth elements involving a plot...... into the field for normal deep-sea sediments....

  3. Determination of REE in urban park soils from Sao Paulo city for fingerprint of traffic emission contamination

    Energy Technology Data Exchange (ETDEWEB)

    Figueiredo, Ana Maria G.; Camargo, Sonia P., E-mail: anamaria@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Sigolo, Joel B., E-mail: jbsigolo@usp.b [Universidade de Sao Paulo (USP), SP (Brazil). Inst. de Geociencias

    2009-07-01

    The study of rare earth elements (REE) distribution in urban environments has become very interesting in the last years, due to the increasing industrial use of these elements. The REE La, Ce and Nd are used in automobile converter catalysts to stabilize the catalyst support and to enhance the oxidation of pollutants. The honeycomb structure has a typical association of a high Ce (and often also La) concentration combined with high concentrations of Platinum Group Elements. Due to thermal and mechanical wear of catalysts, fine particles enriched in REE are released to the environment. These catalyst particles can accumulate in urban soils, mainly in soils located near high density traffic roads. The aim of this paper was to study the REE distribution and ratios in surface soil samples collected in fourteen urban public parks of Sao Paulo city, to assess the influence of vehicular emissions. Instrumental Neutron Activation Analysis (INAA) was used for the REE analysis. The diagrams normalized to chondrite values showed an enrichment of the light REE (La to Sm), in contrast to the heavy REE (Eu to Lu), with a negative anomaly of Eu. The results obtained indicated that the enrichment in REE is not clearly attributed to vehicular traffic, because of high background values associated to the natural geological composition of the soils. (author)

  4. Variational approach for the flow of Ree-Eyring and Casson fluids in pipes

    CERN Document Server

    Sochi, Taha

    2014-01-01

    The flow of Ree-Eyring and Casson non-Newtonian fluids is investigated using a variational principle to optimize the total stress. The variationally-obtained solutions are compared to the analytical solutions derived from the Weissenberg-Rabinowitsch-Mooney equation and the results are found to be identical within acceptable numerical errors and modeling approximations.

  5. [Study on the Geochemical Anomalies Identification of REE Based on HJ-1A-HSI].

    Science.gov (United States)

    Chen, Yong-gan; Wang, Mei-juan; Li, Peng

    2015-11-01

    The characteristic spectral bands of REE do not vary with the occurrence state, cannot be used to identify mineral species, but can prove the existence of its own. Here we report the spectrum characteristics of REE and their compounds by remote sensing wave band from visible light-near infrared, with the quantitative relationship between the contents of REE and absorption index of characteristic spectral bands. The experimental study was carried out in Bayan Obo area, Inner Mongolia. Spectrums and Nd contents of typical rock and ore samples were gathered and analyzed. There is positive correlation between the Nd content, the absorption depth and absorption index of different spectrum characteristics (correlation coefficient > 0.778). Moreover, the correlation between absorption index of 726-772 nm band and Nd content is the best, at 0. 937. As mentioned above, the quantitative model and the inversion information remote sensing geochemical anomaly of Nd were built by the band of HJ-1A-HIS hyperspectral remote sensing data. Our results consistent with 1:200,000 stream sediment geochemical anomalies of Nd. The model provides a new means for rapid extract regional geochemical anomalies of REE.

  6. 3D representation of geochemical data, the corresponding alteration and associated REE mobility at the Ranger uranium deposit, Northern Territory, Australia

    Science.gov (United States)

    Fisher, Louise A.; Cleverley, James S.; Pownceby, Mark; MacRae, Colin

    2013-12-01

    Interrogation and 3D visualisation of multiple multi-element data sets collected at the Ranger 1 No. 3 uranium mine, in the Northern Territory of Australia, show a distinct and large-scale chemical zonation around the ore body. A central zone of Mg alteration, dominated by extensive clinochlore alteration, overprints a biotite-muscovite-K-feldspar assemblage which shows increasing loss of Na, Ba and Ca moving towards the ore body. Manipulation of pre-existing geochemical data and integration of new data collected from targeted `niche' samples make it possible to recognise chemical architecture within the system and identify potential fluid conduits. New trace element and rare earth element (REE) data show strong fractionation associated with the zoned alteration around the deposit and with fault planes that intersect and bound the deposit. Within the most altered portion of the system, isocon analysis indicates addition of elements including Mg, S, Cu, Au and Ni and removal of elements including Ca, K, Ba and Na within a zone of damage associated with ore precipitation. In the more distal parts of the system, processes of alteration and replacement associated with the mineralising system can be recognised. REE element data show enrichment in HREE centred about a characteristic peak in Dy in the high-grade ore zone while LREEs are enriched in the outermost portions of the system. The patterns recognised in 3D in zoning of geochemical groups and contoured S, K and Mg abundance and the observed REE patterns suggest a fluid flow regime in which fluids were predominately migrating upwards during ore deposition within the core of the ore system.

  7. Study of REE behaviors, fluid inclusions, and O, S stable Isotopes in Zafar-abad iron skarn deposit, NW Divandarreh, Kordestan province

    Directory of Open Access Journals (Sweden)

    Mehrdad Barati

    2014-10-01

    Full Text Available Introduction The Zafar-abad iron ore deposit, situated in the NW part of Divandarreh (lat. 36°01'14" and long. 46°58'22". The ore body is located on the northern margin of the Sanandaj-Sirjan igneous metamorphic zone. The Zafar-abad Fe-skarn deposit is one of the important, medium- size mineral deposits in western Iran. REE patterns of skarn magnetite were among others studied in Skarn deposit by (Taylor, 1979 Hydrothermal alteration and fluid-rock interaction significantly affect total contents of REE and their patterns in fluids. Moreover, fractionation of REE by chemical complication, adsorption effects and redox reactions are characteristic processes determining REE behavior during crystallization. Stable isotope data for oxygen and sulfur have been widely used with great success to trace the origin and evolution history of paleo-hydrothermal fluids of meteoric, magmatic, and metamorphic. Materials and methods The present study investigates REE and stable Isotope geochemistry of magnetite and pyrite in Zafar-abad deposit and temperature of trapped fluid inclusions based on geothermometry analysis. In order to study the major, trace and REE compositions of Zafar-abad magnetite, twelve samples were collected from surface of ore exposures. The emphasis during sampling was on ores with primary textures. Discussion The Zafar-abad district is situated in Mesozoic and Cenozoic sedimentary, meta-sedimentary and meta-igneous rocks in Sanandaj-Sirjan igneous metamorphic zone. Sedimentary sequences dominantly composed of calcareous and conglomerate rocks. Various meta-sedimentary rocks are intercalated with the sedimentary rocks, and comprise biotite and muscovite-rich schist, calc-schist, calc-silicate rock. Several distinct ductile tectonic fabrics have been identified around the Zafar-abad deposit. The main ore body at Zafar-abad is in the form of a roughly horizontal, discordant, lens to tabular-shaped body plunging 10° NW, where it appears to

  8. Microbially mediated formation of a new REE enriched Mn-oxide, Ytterby mine, Sweden

    Science.gov (United States)

    Sjöberg, Susanne; Allard, Bert; Rattray, Jayne E.; Callac, Nolwenn; Skelton, Alasdair; Ivarsson, Magnus; Karlsson, Stefan; Sjöberg, Viktor; Dupraz, Christophe

    2016-04-01

    Characterization of a black substance seeping from fractured bedrock in a subterranean tunnel revealed a new, microbially mediated, secondary manganese oxide mineralisation, highly enriched in rare earth elements (REEs). This tunnel is dry and at shallow depth and was built to convert the former Ytterby mine, known for the discovery of yttrium (Y), scandium (Sc) and five rare earth elements, into a fuel deposit for the Swedish Armed Forces. As the type locality of these rare earth elements, the Ytterby mine gave its name to yttrium, ytterbium, erbium and terbium. Geochemical analysis shows that the substance is enriched in REEs with concentrations one to two orders of magnitude higher than the surrounding rocks. Elemental analysis and X-ray diffraction establish that the main component is a manganese oxide of the birnessite type (general formula: [Na,Ca]0.5[Mn(III),Mn(IV)]2O4xAq). There are also minor fractions of calcite, some other manganese oxides, feldspars, quartz and about 1% organic matter, but no iron oxides. Leaching studies (sequential and selective) were performed in order to establish how the minor components are associated with the matrix (in the lattice or merely adsorbed on the outer surface). It shows that the Ytterby birnessite contains about 1% REEs in the lattice, as well as calcium but no sodium. Formation of birnessite by manganese oxidizing bacteria is well-known (e.g. Tebo et al, 2004). Quantitative PCR shows that the total number of bacteria in the Ytterby substance is in the order 1010 cells per g substance while the water feeding the fracture has in the order of 106 cells per ml groundwater. qPCR data further confirm that manganese oxidizing microorganisms are present and that the abundance varies with the seasons. Analysis of the precipitated manganese using electron paramagnetic resonance spectroscopy shows that the substance is composed of two or more components, with one part having a biogenic signature. The occurrence of C31 to C35

  9. REE Mineralization in Kiruna-type Magnetite-Apatite Ore Deposits: Magmatism and Metasomatism

    Science.gov (United States)

    Harlov, D. E.

    2015-12-01

    Magnetite-apatite ore bodies of the Kiruna type occur worldwide and are generally associated with volcanic rocks or volcanism. They also show strong evidence of extensive metasomatism over a wide P-T range. Notable examples include the Kiirunavaara ore body, northern Sweden (Harlov et al., 2002, Chem. Geol., 191, 47-72); the Grängesberg ore body, central Sweden (Jonsson et al., 2010, NGF abstracts, vol 1, 88-89); the Mineville ore body, Adirondacks, New York, USA (McKeown and Klemc, 1956, U.S. Geol Sur Bull (1956), pp. 9-23); the Pea Ridge ore body, SE Missouri, USA (Kerr, 1998, MS Thesis, Univ. Windsor, Windsor, Ontario, Canada 113 pp); the Jurassic Marcona ore body in south-central Peru (Chen et al., 2010, Econ Geol, 105, 1441-1456); and a collection of ore bodies from the Bafq Region, central Iran (Daliran et al., 2010, Geol. Assoc. Canada, Short Course Notes, v. 20, p.147-159). In these ore bodies, low Th and U monazite, xenotime, allanite, REE carbonates, and/or REE fluorides are commonly associated with the apatite as inclusions, rim grains, or as independent grains in the surrounding mineral matrix. High contrast BSE imaging, coupled with EMPA and LA-ICPMS, indicates that the apatite has experienced fluid-induced alteration in the form of (Y+REE) + Na + Si + Cl depletion implying that it served as the source for the (Y+REE) (e.g. Kiirunavaara, northern Sweden; Harlov et al., 2002). Formation of monazite and xenotime associated with fluorapatite, as inclusions or rim grains, has experimentally been demonstrated to originate from the fluorapatite as the result of fluid-aided, coupled dissolution-reprecipitation processes (Harlov et al., 2005, Contrib. Mineral. Petrol. 150, 268-286). This is explains the low Th and U content of the monazite and xenotime. Fluid sources could range from 700-900 °C, residual, acidic (HCl, H2HSO4) grain boundary fluids, remaining after the last stages of ore body crystallization, to later stage, cooler (< 600 °C) (H2O-CO2-(Na

  10. REE behavior and effect factors in AMD-type acidic groundwater at sulfide tailings pond, BS nickel mine, W.A.

    Institute of Scientific and Technical Information of China (English)

    LEI Liang-qi; SONG Ci-an; XIE Xiang-li; LI Yan-hong

    2008-01-01

    AMD(Acid Mine Drainage)-type acidic groundwater (pH<4) from oxidizing sulfide tailings in BS nickel mine (Western Australia) is of higher total rare earth element(REE) contents and Ce enrichment (PAAS normalization), different from setting groundwater (pH>6.5, with lower total REE contents, Ce depletion). While the AMD contaminated groundwater (pH=4.0-6.5) around tailings pond is characterized by transition from acidic to setting groundwater in total REE content, and associated with Ce depletion (like setting groundwater). The light REE in all type groundwater shows up depletion, but its depleted extent in acidic groundwater is more remarkable. This work indicates that REE behavior in AMD-type acidic groundwater is controlled mainly by pH value and metal (Al, Mn and Fe) contents. And the critical pH value that affects REE behavior in ground acidic water would be 4, lower than the previous value (pH=5) that has been believed prevalently in surface acidic waters. The pH could affect REE behavior in groundwater by controlling the solubility of metal (Al, Mn and Fe) hydroxides and the valence of cerium. Finally, light REE depletion in acidic groundwater may due to element affinity. High content Al (affinity with heavy REE) and low content Fe (affinity with light REE) may lead to heavy REE enrichment while light REE relative depletion in water.

  11. Uptake and Effects of Six Rare Earth Elements (REEs) on Selected Native and Crop Species Growing in Contaminated Soils

    Science.gov (United States)

    Carpenter, David; Boutin, Céline; Allison, Jane E.; Parsons, Jessica L.; Ellis, Deanna M.

    2015-01-01

    Rare earth elements (REEs) have become increasingly important metals used in modern technology. Processes including mining, oil refining, discarding of obsolete equipment containing REEs, and the use of REE-containing phosphate fertilizers may increase the likelihood of environmental contamination. However, there is a scarcity of information on the toxicity and accumulation of these metals to terrestrial primary producers in contaminated soils. The objective of this work was to assess the phytotoxicity and uptake from contaminated soil of six REEs (chloride forms of praseodymium, neodymium, samarium, terbium, dysprosium, and erbium) on three native plants (Asclepias syriaca L., Desmodium canadense (L.) DC., Panicum virgatum L.) and two crop species (Raphanus sativus L., Solanum lycopersicum L.) in separate dose-response experiments under growth chamber conditions. Limited effects of REEs were found on seed germination and speed of germination. Effects on aboveground and belowground biomass were more pronounced, especially for the three native species, which were always more sensitive than the crop species tested. Inhibition concentrations (IC25 and IC50) causing 25 or 50% reductions in plant biomass respectively, were measured. For the native species, the majority of aboveground biomass IC25s (11 out of 18) fell within 100 to 300 mg REE/kg dry soil. In comparison to the native species, IC25s for the crops were always greater than 400 mg REE/kg, with the majority of results (seven out of 12) falling above 700 mg REE/kg. IC50s were often not detected for the crops. Root biomass of native species was also affected at lower doses than in crops. REE uptake by plants was higher in the belowground parts than in the above-ground plant tissues. Results also revealed that chloride may have contributed to the sensitivity of the native species, Desmodium canadense, one of the most sensitive species studied. Nevertheless, these results demonstrated that phytotoxicity may be a

  12. Uptake and Effects of Six Rare Earth Elements (REEs on Selected Native and Crop Species Growing in Contaminated Soils.

    Directory of Open Access Journals (Sweden)

    David Carpenter

    Full Text Available Rare earth elements (REEs have become increasingly important metals used in modern technology. Processes including mining, oil refining, discarding of obsolete equipment containing REEs, and the use of REE-containing phosphate fertilizers may increase the likelihood of environmental contamination. However, there is a scarcity of information on the toxicity and accumulation of these metals to terrestrial primary producers in contaminated soils. The objective of this work was to assess the phytotoxicity and uptake from contaminated soil of six REEs (chloride forms of praseodymium, neodymium, samarium, terbium, dysprosium, and erbium on three native plants (Asclepias syriaca L., Desmodium canadense (L. DC., Panicum virgatum L. and two crop species (Raphanus sativus L., Solanum lycopersicum L. in separate dose-response experiments under growth chamber conditions. Limited effects of REEs were found on seed germination and speed of germination. Effects on aboveground and belowground biomass were more pronounced, especially for the three native species, which were always more sensitive than the crop species tested. Inhibition concentrations (IC25 and IC50 causing 25 or 50% reductions in plant biomass respectively, were measured. For the native species, the majority of aboveground biomass IC25s (11 out of 18 fell within 100 to 300 mg REE/kg dry soil. In comparison to the native species, IC25s for the crops were always greater than 400 mg REE/kg, with the majority of results (seven out of 12 falling above 700 mg REE/kg. IC50s were often not detected for the crops. Root biomass of native species was also affected at lower doses than in crops. REE uptake by plants was higher in the belowground parts than in the above-ground plant tissues. Results also revealed that chloride may have contributed to the sensitivity of the native species, Desmodium canadense, one of the most sensitive species studied. Nevertheless, these results demonstrated that

  13. The Overview of the Distribution,Type and Genesis of the Exogenetic Rare Earth Elements(REE)Deposits%外生稀土矿床的分布、类型和成因概述

    Institute of Scientific and Technical Information of China (English)

    许成; 宋文磊; 何晨; 王丽泽

    2015-01-01

    Rare earth elements (REE)are critical metals in the world.Exploration and study of the REE deposits become a hot issue.Exogenetic deposits are one of REE resource.The paper briefly overview geological features and origin of REE deposits from residual-diluvial,fluvial and beach placer,carbonatite and granitoid weathering crust.The weathering type REE deposits are formed by the chemical weathering processes of the REE-rich parent rocks.The initial REE-enrichment of the parent rocks is the premise for the formation of this type deposit,and the weathering crusts have inherited the REE distribution patterns of the primary rocks to a great extend.World presently has great demand for heavy REE (HREE). Granitoid weathering HREE deposits in Nanling region of South China are rare and attract many geologists.Weathering process is secondary extraction and enrichment.Primary HREE mineral formation is a key.However,the questions why the granites having potential to generate rare earth mineralization within weathering crusts mainly occurred and concentrated in Nanling region,and whether the LREE /HREE fractionation of the REE-rich granite is due to the discrepancy of their mag-ma source or the differentiation of the magma during evolution,and how the HREE mineral formed,are still not clear and need more study.%稀土是当今危机资源,勘探和研究稀土矿床是世界热点。外生矿床是重要的稀土来源之一。本文综述了残-坡积、(河流)冲积和海滨砂矿,碳酸盐岩风化壳型,花岗岩风化壳型等稀土矿床地质特征和成因认识。风化壳型稀土矿床是由富稀土的原岩经过地表机械和化学风化作用形成,母岩稀土的最初富集是形成风化壳型稀土矿床的前提,风化壳继承了母岩的稀土特征。目前世界对重稀土的需求最为突出,中国南岭花岗岩风化壳型重稀土矿床为世界之最。风化是后期稀土提炼富集过程,成矿关键在于花岗岩岩浆阶

  14. Investigation of Kpong carbonatite as a potential source for rare earth elements (REEs) using instrumental neutron activation analysis (INAA)

    Energy Technology Data Exchange (ETDEWEB)

    Hayford, M.S.; Akiti, T.T.; Serfor-Armah, Y.; Dampare, S.B. [Ghana Univ., Accra (Ghana). School of Nuclear and Allied Sciences; Ghana Atomic Energy Commission (GAEC), Legon-Accra (Ghana). Nuclear Chemistry and Environmental Research Centre

    2013-07-01

    Instrumental neutron activation analysis (INAA) was used to investigate REEs in carbonatite from Kpong southeastern, Ghana. Total rare earth element (TREEs) obtain were in the range of 540 mg/kg to 705 mg/kg. The total number of rare earth elements (REEs) determined by INAA in the carbonatite rocks from Kpong were 11, namely; La, Ce, Nd, Sm, Eu, Tb, Dy, Ho, Tm, Yb, Lu. The INAA results from the carbonatite show a high enrichment of light rare earth elements (LREEs) deposits, marking the Kpong carbonatite as a potential REE source. (orig.)

  15. REE Enrichment in Early Cambrian Gezhongwu Formation Phosphorous Rock Series in Sanjia, Zhijin County, Guizhou Province, China

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Phosphate concretions from the Gezhongwu Formation at Sanjia, Zhijin County, China, were studied systematically in this work. In terms of the rules of variation of REE, trace elements, major elements and oxides, in combination with the concentration characteristics of small shelly fossils, it is considered that small shelly fossils occurring at the bottom of the Cambrian System contribute a lot to the phosphate concretions and that there are two stages of REE and phosphorus minerogenesis. The phosphate concretions have a good correlation with the contents of REE and phosphorus rather than the abundance of small shelly fossils.

  16. Pomozdino - An anomalous, high-MgO/FeO, yet REE-rich eucrite

    Science.gov (United States)

    Warren, P. H.; Jerde, E. A.; Migdisova, L. F.; Iaroshevskii, A. A.

    1990-01-01

    A new chemical analysis and petrographic data for the Pomozdino basaltic achondrite are presented. Earlier indications that Pomozdino is a eucrite and that it is a monomict breccia with an anomalous, REE-rich, yet high-MgO/FeO bulk composition, are confirmed. Characteristics such as texture, composition, and REE concentration are examined and compared to those in other publications. A model for the origin of this meteorite, as a partial cumulate with an uncommonly high content of trapped liquid, is found to be preferable. Two alternatives of the origin are suggested, one of which implies that the parent melt is roughly similar in composition to Stannern. The other considers Pomozdino as a possible primary partial melt, derived from a source region far more magnesian than generally envisaged for the sources of primary eucritic partial melts. It is concluded that at least some Stannern-like eucrites were involved in fractional crystallization, and thus do not represent primary partial melts.

  17. Neutron Activation Analysis of the Rare Earth Elements (REE) - With Emphasis on Geological Materials

    Science.gov (United States)

    Stosch, Heinz-Günter

    2016-08-01

    Neutron activation analysis (NAA) has been the analytical method of choice for rare earth element (REE) analysis from the early 1960s through the 1980s. At that time, irradiation facilitieswere widely available and fairly easily accessible. The development of high-resolution gamma-ray detectors in the mid-1960s eliminated, formany applications, the need for chemical separation of the REE from the matrix material, making NAA a reliable and effective analytical tool. While not as precise as isotopedilution mass spectrometry, NAA was competitive by being sensitive for the analysis of about half of the rare earths (La, Ce, Nd, Sm, Eu, Tb, Yb, Lu). The development of inductively coupled plasma mass spectrometry since the 1980s, together with decommissioning of research reactors and the lack of installation of new ones in Europe and North America has led to the rapid decline of NAA.

  18. Re-Os dating of pyrite from Giant Bayan Obo REE-Nb-Fe deposit

    Institute of Scientific and Technical Information of China (English)

    LIU Yulong; YANG Gang; CHEN Jiangfeng; DU Andao; XIE Zhi

    2004-01-01

    Six pyrite samples from the giant Bayan Obo REE-Nb-Fe deposit are dated by Re-Os technique. Pyrite studied is associated with barite and separated from a vein cutting REE mineralization. Pyrites analyzed contain 16-30 ng Re and 0.10-0.16 ng Os, and yield a Caledonian isochron age of 439 ± 86 Ma. High Re/Os ratio, low Os concentration and highly radiogenic Os isotopic ratios of these samples suggest that they are of crustal origin. The northern margin of the North China Block was a passive continental margin, but not a subduction zone with enormous volcanic activities in the Early Paleozoic Era. Our Re-Os result provides new evidences, showing that Bayan Obo deposit experienced a thermal disturbance of crustal origin in the Caledonian time and some isotopic systems recorded only the time of the disturbance, not the mineralization age.

  19. SD-REE: A Cryptographic Method to Exclude Repetition from a Message

    CERN Document Server

    Dey, Somdip

    2012-01-01

    In this paper, the author presents a new cryptographic technique, SD-REE, to exclude the repetitive terms in a message, when it is to be encrypted, so that it becomes almost impossible for a person to retrieve or predict the original message from the encrypted message. In modern world, cryptography hackers try to break a code or cryptographic algorithm [1,2] or retrieve the key, used for encryption, by inserting repetitive bytes / characters in the message and encrypt the message or by analyzing repetitions in the encrypted message, to find out the encryption algorithm or retrieve the key used for the encryption. But in SD-REE method the repetitive bytes / characters are removed and there is no trace of any repetition in the message, which was encrypted.

  20. Cathodoluminescence emission of REE (Dy, Pr and Eu) doped LaAlO3 phosphors

    Science.gov (United States)

    Boronat, C.; Rivera, T.; Garcia-Guinea, J.; Correcher, V.

    2017-01-01

    Luminescence emission from rare earth (REE) ions doped materials are being of interest since can be employed as scintillators, catalysts, battery and magnetic materials, etc. We herein report on the preliminary results obtained from the cathodoluminescence (CL) properties of undoped LaAlO3 (LAO) and LaAlO3: REE3+ (REE=Dy3+, Pr3+ and Eu3+) samples synthesized by a sol-gel process based on the Pechini's method with a spray-drying technique. The samples, previously characterized by means of Environmental Scanning Electron Microscopy and Energy Dispersive X-Ray Analysis Spectrometry, display CL spectra with well-defined peaks that could specifically be associated with the LAO structure (in the range of 300-450 nm) and point defects (from 450 to 800 nm) spectral regions. The observed wavebands are as follows: (i) 480 and 570 from the Dy-doped LAO correspond respectively to 4F9/2→6H15/2 and 4F9/2→6H13/2 transitions, (ii) 490-638 from the Pr-doped LAO is linked to 3P0→3H4, 1D2→3H4 transitions and (iii) 590 and 620 where the dopant Eu3+ gives rise to 5D0→7F1 and 5D0→7F2 transitions and (iv) a UV-blue broad band is associated with NBHOC in undoped LAO. Such emissions are due to the presence of the 4f electrons of rare earth ions that are shielded by the outer 5s and 5p electrons, the intra-4f emission spectra of REE that induce sharp and narrow wavebands.

  1. An Overview on the Possibility of Scandium and REE Occurrence in Sulawesi, Indonesia

    Directory of Open Access Journals (Sweden)

    Adi Maulana

    2016-08-01

    Full Text Available The development in modern-high technology application is growing rapidly, resulting in the constant supply of critical metal and rare earth elements (REE. Currently, resources of these elements are restricted and new source of these elements need to be discovered accordingly. Scandium (Sc as one of critical metals is an important metal for electrolyte of solid oxide fuel cells and other advance technology. In addition, REE are the important elements in the use of permanent magnets and rechargeable batteries. This manuscript reports an overview on the possibility of scandium and rare earth element occurrences in Sulawesi. Sc is concentrated in limonite layers in Soroako ultramafic rocks as a result of Fe3+ site substitution of mafic minerals (pyroxene, amphibole, etc. during a laterization process. REE are enriched in association with clay minerals in B horizon from heavily weathered granitic rocks in Palu and Masamba, suggesting the possibility of ion-adsorption style mineralization. The lateritic soil of the ultramafic rocks and the weathered crusts of the granitic rocks in Sulawesi could be the potential sources of scandium and rare earth elements, respectively.

  2. Chemical speciation and bioavailability of rare earth elements (REEs) in the ecosystem: a review.

    Science.gov (United States)

    Khan, Aysha Masood; Bakar, Nor Kartini Abu; Bakar, Ahmad Farid Abu; Ashraf, Muhammad Aqeel

    2016-10-10

    Rare earths (RE), chemically uniform group of elements due to similar physicochemical behavior, are termed as lanthanides. Natural occurrence depends on the geological circumstances and has been of long interest for geologist as tools for further scientific research into the region of ores, rocks, and oceanic water. The review paper mainly focuses to provide scientific literature about rare earth elements (REEs) with potential environmental and health effects in understanding the research. This is the initial review of RE speciation and bioavailability with current initiative toward development needs and research perceptive. In this paper, we have also discussed mineralogy, extraction, geochemistry, analytical methods of rare earth elements. In this study, REEs with their transformation and vertical distribution in different environments such as fresh and seawater, sediments, soil, weathering, transport, and solubility have been reported with most recent literature along key methods of findings. Speciation and bioavailability have been discussed in detail with special emphasis on soil, plant, and aquatic ecosystems and their impacts on the environment. This review shows that REE gained more importance in last few years due to their detrimental effects on living organisms, so their speciation, bioavailability, and composition are much more important to evaluate their health risks and are discussed thoroughly as well.

  3. Resting Energy Expenditure and Its Relationship With Patterns of Obesity and Visceral Fat Area in Chinese Adults

    Institute of Scientific and Technical Information of China (English)

    WEI-PING JIA; MING YANG; XIN-YU SHAO; YU-QIAN BAO; JUN-XI LU; KUN-SAN XIANG

    2005-01-01

    Objective To investigate the relationship between resting energy expenditure (REE) and patterns of obesity/regional fat parameters in Chinese adults. Methods Body mass index (BMI), fat mass (FM), fat-free mass (FFM) were assessed in 109 Chinese adults (52 men and 57 women), and their abdominal visceral adipose tissue area (VA) and subcutaneous fat area (SA) were measured using magnetic resonance imaging (MRI) measurements. REE was measured with indirect calorimetry and compared with normal and obese subjects. Multivariate analysis was used to study the factors related to REE. Results The resting energy expenditure per kilogram of body weight (REE/kg) was closely related with the area of abdominal visceral fat measured with MRI. REE/kg was significantly lower in overweight/obesity subjects than in normal-weighted subjects, and significantly lower in subjects with abdominal obesity (VA≥100 cm2) than in subjects with non-abdominal obesity (VA< 100 cm2, BMI≥25 kg/m2). In the stepwise regression analysis of REE/kg on regional fat parameters, VA in men and women and SA in women were independent factors reversely related to REE/kg. Conclusion REE/kg is associated with the visceral fat area and more prominent in men. REE/kg can be used as an index in the pathophysiology of intra-abdominal obesity.

  4. Assessing anthropogenic levels, speciation, and potential mobility of rare earth elements (REEs) in ex-tin mining area.

    Science.gov (United States)

    Khan, Aysha Masood; Yusoff, Ismail; Bakar, Nor Kartini Abu; Bakar, Ahmad Farid Abu; Alias, Yatimah

    2016-12-01

    A study was carried out to determine the level of rare earth elements (REEs) in water and sediment samples from ex-mining lakes and River in Kinta Valley, Perak, Malaysia. Surface water and sediments from an ex-mining lake and Kinta River water samples were analyzed for REEs by inductively coupled plasma mass spectrometry. The total concentration of REEs in the ex-mining lake water samples and sediments were found to be 3685 mg/l and 14159 mg/kg, respectively, while the total concentration of REEs in Kinta River water sample was found to be 1224 mg/l. REEs in mining lake water were found to be within 2.42 mg/l (Tb) to 46.50 mg/l (Ce), while for the Kinta River, it was 1.33 mg/l (Ho) to 29.95 mg/l (Ce). Sediment samples were also found with REEs from 9.81 mg/kg (Ho) to 765.84 mg/kg (Ce). Ce showed the highest average concentrations for mining lake (3.88 to 49.08 mg/l) and Kinta River (4.44 to 33.15 mg/l) water samples, while the concentration of La was the highest (11.59 to 771.61 mg/kg) in the mining lake sediment. Lu was shown to have the highest enrichment of REEs in ex-mining lake sediments (107.3). Multivariate statistical analyses such as factor analysis and principal component analysis indicated that REEs were associated and controlled by mixed origin, with similar contributions from anthropogenic and geogenic sources. The speciation study of REEs in ex-tin mining sediments using a modified five-stage sequential extraction procedure indicated that yttrium (Y), gadolinium (Gd), and lanthanum (La) were obtained at higher percentages from the adsorbed/exchanged/carbonate fraction. The average potential mobility of the REEs was arranged in a descending order: Yb > Gd > Y = Dy > Pr > Er > Tm > Eu > Nd > Tb > Sc > Lu > Ce > La, implying that under favorable conditions, these REEs could be released and subsequently pollute the environment.

  5. Modeling the geochemical distribution of rare earth elements (REEs using multivariate statistics in the eastern part of Marvast placer, the Yazd province

    Directory of Open Access Journals (Sweden)

    Amin Hossein Morshedy

    2017-07-01

    is to maximize both the similarity within each cluster and the difference between clusters, and finally find the structure in the data. Nowadays, cluster analysis is applied in many disciplines: biology, botany, medicine, psychology, geography, marketing, image processing, psychiatry, archaeology, etc. (Everitt et al., 2011. To execute a partitioning algorithm, the principal components analysis (PCA algorithm is applied for feature selection, feature extraction and dimension reduction. Hierarchical clustering can be utilized to provide a nested sequence of partitions with bottom-up or top-down methods based on similarity. The single linkage and complete linkage are the most popular hierarchical algorithms (Jain et al., 1999; Ji et al., 2007. Results and discussion The REE chondrite-normalized pattern for the eastern area in the Marvast placer represents a high match to the standard pattern of monazite. This pattern shows the positive anomaly of Ce and the negative anomaly of Eu. To determine the distribution of REEs concentration, 2D interpolation maps were plotted in three groups of light, middle, and heavy REEs (LREE, MREE, and HREE, which were indicated in the geochemical anomaly at the south and south-west of the area. The relative ratios of (LREE/HREE and (Ce/Eu exposed the high proportion of LREEs to HREEs. In the next section, the hierarchical clustering algorithm was employed to partition the data in the feature and sample levels. The elements portioning demonstrated four separated groups, which can be related to atomic and chemical structures. The studied region was divided into four zones by the clustering approach. The fourth zone confine coincided with the REE anomaly area. Finally, PCA was applied as the multivariate statistical tool to this dataset. Hence three principal components modeled over 90% of the variance. For the first component, the distribution map of load factor has a good agreement with anomaly area. References Alipour-Asll, M., Mirnejad

  6. Hydrothermal scavenging on the Juan de Fuca Ridge: {sup 230}Th{sub xs}, {sup 10}Be, and REEs in ridge-flank sediments

    Energy Technology Data Exchange (ETDEWEB)

    German, C.R.; Colley, S.; Higgs, N.C.; Ludford, E.M. [Southampton Oceanography Centre, Southampton (United Kingdom)] [and others

    1997-10-01

    We have investigated the geochemistry of a hydrothermally enriched sediment core recovered from the western flank of the N.Cleft Segment, Juan de Fuca Ridge, {approximately}8km west of the {open_quotes}MegaPlume{close_quotes} area previously identified near 45{degrees}N. The core contains varying biogenic, lithogenic, and hydrothermal components, as reflected in CaCO{sub 3}, Al, and Fe contents, respectively. Horizons of pronounced hydrothermal input, in core-top sediments and at depth, exhibit increased concentrations of Fe, Cu, Zn, and Pb and shifts in Pb isotopic compositions toward nonradiogenic (MORB/hydrothermal) values. REE concentrations co-vary with hydrothermal Fe down-core, and shale-normalised REE distribution patterns exhibit both negative Ce-anomalies and positive Eu-anomalies, indicative of input from plume-particle fall-out. Unsupported {sup 230}Th{sub xs} activities down-core are consistent with continuous slow sediment accumulation rates of 0.54 cm/ky for 200 ky since the deposition of the deeper Fe-rich horizon. {sup 10}Be{sub (0)}, and {sup 9}Be isotope concentrations also co-vary with hydrothermal Fe down-core and exhibit {sup 10}Be{sub (0)} ratios which approach that of Pacific Ocean deep water, indicative of a seawater-scavenging source. 49 refs., 9 figs., 7 tabs.

  7. Experimental Study on the Effects of Organic Acids on the Dissolution of REE in the Weathering Crust of Granite

    Institute of Scientific and Technical Information of China (English)

    陈炳辉; 毋福海; 刘琥琥

    2001-01-01

    The results of REE leached by some organic acids with various concentrations and water/rock ratios for different durations from a mixed sample of the weathering crust of a granite in Gonghe, Guangdong, China, showed that: 1 ) the contents of REE leached increase with increasing concentrations of the organic acids; 2) the contents of REE leached by 0.01 mol/L organic acids increase with increasing water/rock ratio; 3) the interaction between the organic acids and the samples enhances the pH value of the medium and the contents of REE leached tend to increase with decreasing pH value; and 4) compared with those leached by ammonia sulfate, the REE leached by the organic acids are characterized by a weaker negative Ce anomaly, a stronger negative Eu anomaly, and lower (La/Sm)N and (Gd/Yb)N ratios, indicating that the organic acids have made contributions to the fractionation of REE in the weathering crust.

  8. Experimental Study on the Effects of Organic Acids on the Dissolution of REE in the Weathering Crust of Granite

    Institute of Scientific and Technical Information of China (English)

    陈炳辉; 毋福海; 等

    2001-01-01

    The results of REE leached by some organic acids with various concentrations and water/rock ratios for different durations from a mixed samples of the weathering crust of a granite in Gonghe,Guangdong,China,showed that:1)the contents of REE leached increase with increasing concentrations of the organic acids;2) the contents of REE leached by 0.01mol/L organic acids increase with increasing water/rock ration;3) the interaction between the organic acids and the samples enhances the pH value of the medium and the contents of REE leached tend to increase with decreasing pH value;and 4) compared with those leached by ammonia sulfate,the REE leached by the organic acids are characterized by a weaker negative C e anomaly,a stronger negative Eu anomaly,and lower(La/Sm)N and (Gd/Yb)N ratios,indicating that the organic acids have made contributions to the fractionation of REE in the weathering crust.

  9. Stages of weathering mantle formation from carbonate rocks in the light of rare earth elements (REE) and Sr-Nd-Pb isotopes

    Science.gov (United States)

    Hissler, Christophe; Stille, Peter

    2015-04-01

    Weathering mantles are widespread and include lateritic, sandy and kaolinite-rich saprolites and residuals of partially dissolved rocks. These old regolith systems have a complex history of formation and may present a polycyclic evolution due to successive geological and pedogenetic processes that affected the profile. Until now, only few studies highlighted the unusual high content of associated trace elements in weathering mantles originating from carbonate rocks, which have been poorly studied, compared to those developing on magmatic bedrocks. For instance, these enrichments can be up to five times the content of the underlying carbonate rocks. However, these studies also showed that the carbonate bedrock content only partially explains the soil enrichment for all the considered major and trace elements. Up to now, neither soil, nor saprolite formation has to our knowledge been geochemically elucidated. Therefore, the aim of this study was to examine more closely the soil forming dynamics and the relationship of the chemical soil composition to potential sources. REE distribution patterns and Sr-Nd-Pb isotope ratios have been used because they are particularly well suited to identify trace element migration, to recognize origin and mixing processes and, in addition, to decipher possible anthropogenic and/or "natural" atmosphere-derived contributions to the soil. Moreover, leaching experiments have been applied to identify mobile phases in the soil system and to yield information on the stability of trace elements and especially on their behaviour in these Fe-enriched carbonate systems. All these geochemical informations indicate that the cambisol developing on such a typical weathering mantle ("terra fusca") has been formed through weathering of a condensed Bajocian limestone-marl facies. This facies shows compared to average world carbonates important trace element enrichments. Their trace element distribution patterns are similar to those of the soil

  10. 87Sr/ 86Sr, 143Nd/ 144Nd and REEs in Silurian phosphatic fossils

    Science.gov (United States)

    Bertram, C. J.; Elderfield, H.; Aldridge, R. J.; Conway Morris, S.

    1992-09-01

    The feasibility of using the chemistry of phosphatic fossil material to trace palaeo-seawater composition for the Silurian has been evaluated. Contrary to Recent material, fossil fish are shown to be unreliable for Sr isotope stratigraphy. Conodonts, however, may be used by employing 0.2M HNO 3 dissolution, except for samples showing degrees of thermal maturation greater than colour alteration index (CAI) values of 2.5. Samples from the same stratigraphic levels from the U.K., Czechoslovakia, Gotland and the U.S.A. gave similar 87Sr/ 86Sr ratios, suggesting that they have recorded the original seawater value. Significant inter-specific differences occur in REE concentrations and Nd isotopic compositions of conodont elements, and Ce and Eu anomalies vary with REE content. This suggests that artefacts are introduced at the same time that large amounts of REEs are incorporated into the apatite. Preliminary results for the Sr isotopic composition of Silurian seawater are presented. Values are generally lower than previously suggested, showing an increase in 87Sr/ 86Sr from ˜ 0.70825 at 435 Ma rising to ˜ 0.70875 at 418 Ma and levelling off in the Late Silurian. The overall rate of increase in seawater ratio is about2-3 × 10 -5 Ma -1 and can be accounted for by the widespread decrease in volcanism compared with the Ordovician; a proportionally greater flux of Sr to the oceans from continental erosion of only ˜ 10% would account for the long-term increase in seawater 87Sr/ 86Sr ratio throughout the Silurian.

  11. Examination of Sarikaya(Yozgat-Turkey) iron mineralization with rare earth element(REE) method

    Institute of Scientific and Technical Information of China (English)

    Nursel; OKSUZ; Sukru; KOC

    2010-01-01

    Iron mineralizations in the study area are found in amphibolites in the localities of Buyukoren,Uzunkuyu-Atkayasi,and Karabacak and they display a predominantly banded texture.Their paragenesis is dominated by magnetite and hematite.In this study,iron mineralizations in Sarikaya were examined in terms of rare earth element(REE) contents and attempts were made to determine some physicochemical conditions that had an impact upon their formation.For this purpose,42 ore samples and 17 enriched magnetite samples...

  12. Laterites-bearing REEs,Wadi Natash,Southeastern Desert,Egypt

    Institute of Scientific and Technical Information of China (English)

    Mohamed; El-Ahmady; Ibrahim

    2010-01-01

    The present paper recorded the occurrence of laterites-bearing REEs in Natash area.Natash laterite deposits occur as horizons(5-15 m in thickness) at the boundary between the Cretaceous sandstones,and Natash flows.Laterite was recorded in more than twenty six occurrence distributed over an area of about 500 km2 along and around Wadi Natash.It ranges in color from light-grey,dark-grey to reddish-brown.The distribution of laterite deposits is structural controlled.Mineralogical results of laterites proved the...

  13. Geochemistry of Rare Earth Elements (REE) in the Weathered Crusts from the Granitic Rocks in Sulawesi Island, Indonesia

    Institute of Scientific and Technical Information of China (English)

    Adi Maulana; Kotaro Yonezu; Koichiro Watanabe

    2014-01-01

    We report for the first time the geochemistry of rare earth elements (REE) in the weath-ered crusts of I-type and calc-alkaline to high-K (shoshonitic) granitic rocks at Mamasa and Palu re-gion, Sulawesi Island, Indonesia. The weathered crusts can be divided into horizon A (lateritic profile) and B (weathered horizon). Quartz, albite, kaolinite, halloysite and montmorrilonite prevail in the weathered crust. Both weathered profiles show that the total REE increased from the parent rocks to the horizon B but significantly decrease toward the upper part (horizon A). LREE are enriched toward the upper part of the profile as shown by La/YbN value. However, HREE concentrations are high in horizon B1 in Palu profile. The total REE content of the weathered crust are relatively elevated com-pared to the parent rocks, particularly in the lower part of horizon B in Mamasa profile and in horizon B2 in Palu profile. This suggests that REE-bearing accessory minerals may be resistant against weath-ering and may remain as residual phase in the weathered crusts. The normalized isocon diagram shows that the mass balance of major and REE components between each horizon in Mamasa and Palu weathering profile are different. The positive Ce anomaly in the horizon A of Mamasa profile indicated that Ce is rapidly precipitated during weathering and retain at the upper soil horizon.

  14. Behaviour of REEs in a tropical estuary and adjacent continental shelf of southwest coast of India: Evidence from anomalies

    Indian Academy of Sciences (India)

    P M Deepulal; T R Gireesh Kumar; C H Sujatha

    2012-10-01

    The distribution and accumulation of the rare earth elements (REE) in the sediments of the Cochin Estuary and adjacent continental shelf were investigated. The rare earth elements like La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu and the heavy metals like Mg, V, Cr, Mn, Fe, Cu, Zn, U, Th were analysed by using standard analytical methods. The Post-Archean Australian Shale composition was used to normalise the rare earth elements. It was found that the sediments were more enriched with the lighter rare earth elements than the heavier ones. The positive correlation between the concentrations of REE, Fe and Mn could explain the precipitation of oxyhydroxides in the study area. The factor analysis and correlation analysis suggest common sources of origin for the REEs. From the Ce-anomalies calculated, it was found that an oxic environment predominates in all stations except the station No. 2. The Eu-anomaly gave an idea that the origin of REEs may be from the feldspar. The parameters like total organic carbon, U/Th ratio, authigenic U, Cu/Zn, V/Cr ratios revealed the oxic environment and thus the depositional behaviour of REEs in the region.

  15. DEMNUni: ISW, Rees-Sciama, and weak-lensing in the presence of massive neutrinos

    CERN Document Server

    Carbone, Carmelita; Dolag, Klaus

    2016-01-01

    We present, for the first time in the literature, a full reconstruction of the total (linear and non-linear) ISW/Rees-Sciama effect in the presence of massive neutrinos, together with its cross-correlations with CMB-lensing and weak-lensing signals. The present analyses make use of all-sky maps extracted via ray-tracing across the gravitational potential distribution provided by the "Dark Energy and Massive Neutrino Universe" (DEMNUni) project, a set of large-volume, high-resolution cosmological N-body simulations, where neutrinos are treated as separate collisionless particles. We correctly recover, at $1-2\\%$ accuracy, the linear predictions from CAMB. Concerning the CMB-lensing and weak-lensing signals, we also recover, with similar accuracy, the signal predicted by Boltzmann codes, once non-linear neutrino corrections to Halofit are accounted for. Interestingly, in the ISW/Rees-Sciama signal, and its cross correlation with lensing, we find an excess of power with respect to the massless case, due to free ...

  16. New Methodological Approach to Investigation of Kinetics of REE Extraction in Nonstationary Conditions

    Institute of Scientific and Technical Information of China (English)

    Kopyrin A A; Fomichev A A; Afonin M A; Todd T A

    2007-01-01

    The influence of periodical oscillations of the temperature on extraction and stripping processes in the extraction systems was studied. Two extraction systems were investigated: (1) 6 mol·L-1 NaNO3-Nd(NO3)3-Pr(NO3)3-TBP-kerosene and (2) [Nd(NO3)3·3TBP]-[Pr(NO3)3·3TBP]-kerosene -0.1 mol·L-1 HNO3. Mathematical modeling of the nonstationary membrane extraction has been enhanced by including the dependence of the extraction rate constants on temperature. The values of activation energy for direct and reverse extraction and stripping reactions of Pr and Nd were calculated from experimental temporal dependencies of metal concentration and temperature by solving the reverse kinetics problem using the proposed mathematical model. A series of experiments with periodical oscillations of the temperature on the extraction system for the separation of rare earth elements (REE) using bulk liquid membrane between two extractors were performed. The mathematical model adequately describes the experimental data. The optimization of the extraction process for separation of REE by liquid membrane, under the influence of periodical oscillation of the temperature, was made based on the extraction rate constants and activation energies. The optimal conditions of separation by liquid membrane were found: frequency and amplitude of thermal oscillations, liquid membrane flow rate, and optimal ratio between organic and aqueous phase in extractors.

  17. Hf, Zr, and REE partition coefficients between ilmenite and liquid - Implications for lunar petrogenesis

    Science.gov (United States)

    Nakamura, Y.; Fujimaki, H.; Nakamura, N.; Tatsumoto, M.; Mckay, G. A.

    1986-01-01

    Partition coefficients (D) between ilmenite and coexisting liquid were determined under near-lunar conditions for Hf, Zr, and REE. Through isotope dilution analysis, ilmenite D values of 0.41 and 0.33 were obtained for Hf and Zr respectively, values significantly lower than those of ilmenite from a kimberlite megacryst. Partition coefficients of REE for the synthesized ilmenite are slightly smaller than those of ilmenite from the kimberlite megacryst, and the lunar (Lu) partition coefficient is 0.056. These results suggest that ilmenite was significant in the lunar-Hf evolution of lunar mare basalts. Using lunar and Hf D values for ilmenite, the Lu-Hf evolution of lunar cumulates and the coexisting magma was examined for various crystallization sequences. The Lu-Hf variation trend of most high-Ti mare basalts is explained by a small degree of partial cumulate melting, though a higher degree is required to explain the variation of very low-Ti basalts, green glass, and Apollo 12 low-Ti basalts. Apollo 15 low-Ti basalts may require chromite crystallization as well.

  18. Geochemistry of rare earth elements (REEs) in coal from magmatic intrusion area from Wolonghu Coal Mine%卧龙湖煤矿岩浆侵入区煤中稀土元素的地球化学特征

    Institute of Scientific and Technical Information of China (English)

    姜萌萌; 刘桂建; 吴斌; 郑刘根

    2012-01-01

    以淮北卧龙湖煤矿包含岩浆岩、煤层的剖面为研究对象,通过对岩浆岩、煤岩混合带、高变质煤样品采集,结合逐级化学提取实验,采用等离子体质谱(ICP-MS)对原煤样、岩浆岩样、煤灰分以 及煤和岩浆岩逐级提取实验中各种提取物的稀土元素进行了测试,系统、深入地研究了稀土元素的含量特征、分布模式以及赋存状态.研究结果表明,岩浆岩在侵入过程中与煤层间发生一定的物质交换作用,岩样与煤样中的稀土元素分布模式相差较大,逐级化学提取实验结果表明煤和岩浆岩中稀土元素都是以硅酸盐结合态占主导,但煤中稀土元素主要来源于陆源碎屑的供给.%Magmatic rock samples and adjacent coal samples were collected from a vertical section in the Wolonghu Coal Mine, Huaibei. The chemical extraction experiments were carried out, and the abundances of rare earth elements (REEs) in samples and coal ashes were determined by inductively couple-plasma mass spectrometry (ICP-MS). The occurrences of REEs were studied using sequential chemical extraction Experiment (SCEE) in different extraction liquids and conditions. The characterizations of the concentration, distribution patterns and the occurrence of REEs were analyzed. The results show that exchange of material between the magma and the coals occurred in the process of magmatic intrusion. Due to the superimposition of coal-forming microenvironment and magmatic intrusion, the distribution patterns of magma and coals are different. The result of SCEE shows that REEs are mainly distributed in sialic state, and that the source of REEs is terrigenous.

  19. Zr, Hf, U, Th and REE-Fertile Lower Proterozoic Potassic Granite from Parts of Andhra Pradesh, South India

    Institute of Scientific and Technical Information of China (English)

    Yamuna SINGH

    2004-01-01

    The medium- to coarse-grained and porphyritic granitoid of Dharmawaram, Karimnagar district, Andhra Pradesh, south India is a biotite-hornblende granite with notable contents of rare metal (Zr, Hf, Th) and rare earth (including Y) minerals like zircon, thorite, allanite, monazite and xenotime. Chemically, it is metaluminous (average A/C+N+K = 0.95)-type, potassic (ay. 5% K2O) granite, with dominantly sub-alkaline characters. It shows up to 8 times enrichment of rare metals (Zr, Hf, U, Th) and rare earths (including Y, Sc), with reference to their abundances in normal unevolved granite, and hence, fertile for some of these elements. Field, petrological, geochemical and isotopic data of potassic granite (PG) indicate involvement of silica-rich metasedimentary-basic crustal rocks (amphibole-quartzite,amphibolite, hornblende-biotite gneiss, etc.) in its genesis, at a depth range of 30 km. Further, chondrite-normalized REE patterns demonstrate that low-degree partial melting of source rocks is the major controlling factor in the genesis of PG.Mild negative Eu-anomaiy (av. Eu/Eu* = 0.48), plots of Ba-Rb-Sr in the field of anomalous granite and K/Rb ratios (av.239) in the range that is shown by normal unevolved granite together indicate less fractionated nature of the PG. Limited fractionation of metalumination-type, involving hornblende, led to occasional weak alumina saturation. Interestingly,geochemical and petrogenetic features of the studied PG broadly match with those potassic granites which are already known to host anomalously high enrichment of rare metals and rare earths in other parts of Andhra Pradesh and adjoining Kamataka.

  20. Carbonate-silicate melt immiscibility, REE mineralising fluids, and the evolution of the Lofdal Intrusive Suite, Namibia

    Science.gov (United States)

    Bodeving, Sarah; Williams-Jones, Anthony E.; Swinden, Scott

    2017-01-01

    The Lofdal Intrusive Suite, Namibia, consists of calcio-carbonatite and silica-undersaturated alkaline intrusive rocks ranging in composition from phono-tephrite to phonolite (and nepheline syenite). The most primitive of these rocks is the phono-tephrite, which, on the basis of its Y/Ho and Nb/Ta ratios, is interpreted to have formed by partial melting of the mantle. Roughly linear trends in major and trace element contents from phono-tephrite to phonolite and nepheline syenite indicate that the latter two rock types evolved from the phono-tephrite by fractional crystallisation. The nepheline syenite, however, has a lower rare earth element (REE) content than the phonolite. The carbonatite has a primitive mantle-normalised REE profile roughly parallel to that of the silica-undersaturated alkaline igneous rocks, although the absolute REE concentrations are higher. Like the phono-tephrite, it also has a mantle Y/Ho ratio. However, the Nb/Ta and Zr/Hf ratios are significantly higher. Moreover, the carbonatite displays strong negative Ta, Zr and Hf anomalies on spidergrams, whereas the silicate rocks display positive anomalies for these elements. Significantly, this behaviour is predicted by the corresponding carbonatite-silicate melt partition coefficients, as is the behaviour of the REE. Based on these observations, we interpret the carbonatite to represent an immiscible liquid that exsolved from the phono-tephrite or possibly the phonolite melt. The result was a calcio-carbonatite that is enriched in the heavy REE (HREE) relative to most other carbonatites. Fluids released from the corresponding magma are interpreted to have been the source of the REE mineralisation that is currently the target of exploration.

  1. Isotope U-Pb age on single zircon and REE distribution in rocks and zircon from paleoproterozoic Kandalaksha-Kolvitsa complex Baltic shield

    Science.gov (United States)

    Steshenko, Ekaterina; Bayanova, Tamara; Drogobuzhskaya, Svetlana; Lyalina, Ludmila; Serov, Pavel; Chashchin, Viktor; Elizarov, Dmitriy

    2017-04-01

    Kandalaksha-Kolvitsa paleoproterozoic complex located in the N-E part of Baltic shield and consists of three zones. Marginal zone (mesocratic metanorite) lies at the base of the massif. Main zone is composed of leucocratic metagabbro. The upper zone is alteration of mataanorthosite and leucocratic metagabbro. All rocks were subjected to granulate and anorthositic metamorphism. Age of magmatic crystallization of the massif was determined for the first time, using the U-Pb isotope method for single zircon grains. Three fractions of single zircons from anorthosite of the Kandalaksha massif gave precise U-Pb age of 2435.5 ± 4.8 Ma. For the first time REE concentration (WR) was determined using a quadrupole mass spectrometer (Agilent 7500 ce ICP-MS) in the main varieties of rocks of the Kandalaksha-Kolvitsa paleoproterozoic complex. Anorthosite and leucocratic metagabbros (main zone) are characterized by a flat spectrum distribution of HREE, which were normalized by [1]. The REE pattern is characterized by significant positive anomalies of Eu ((Eu / Eu *)n = 3.72-3.91) in anorthosite and leucogabbros and 7.26 - in ortoamfibolitah. General content of individual elements that are common for this type of rocks: Cen = 5.82-8.54, Ybn = 1.54-1.58, which indicates that the process of crystallization of the rock occurred with predominant accumulation of plagioclase. According to geochemical and Nd-Sr isotopic data (ISr=0.702 - 0.706, ɛNd(T) = +1 - (-3)) Kandalaksha Kolvitsa complex, appear to have a general plume source with Paleoproterozoic layered intrusions of the Baltic Shield [2] Distribution of REE (ELAN-9000 ICP-MS) in zircon have a typical magmatic species: a positive Ce, negative Eu anomaly and HREE flat spectrum. Titanium content in zircons were measured for the calculation of their crystallization temperature with 8350C. These data are evidence of magmatic origin of zircon [3]. The scientific researches are supported by RFBR (projects № 15-35-20501, № 16

  2. Geology and genesis of the Toongi rare metal (Zr, Hf, Nb, Ta, Y and REE) deposit, NSW, Australia, and implications for rare metal mineralization in peralkaline igneous rocks

    Science.gov (United States)

    Spandler, Carl; Morris, Caitlin

    2016-12-01

    The Toongi Deposit, located in central NSW, Australia, hosts significant resources of Zr, Hf, Nb, Ta, Y and REE within a small (ca. 0.3 km2), rapidly cooled trachyte laccolith. Toongi is part of regional Late Triassic to Jurassic alkaline magmatic field, but is distinguished from the other igneous bodies by its peralkaline composition and economically significant rare metal content that is homogenously distributed throughout the trachyte body. The primary ore minerals are evenly dispersed throughout the rock and include lueshite/natroniobite and complex Na-Fe-Zr-Nb-Y-REE silicate minerals dominated by a eudialyte group mineral (EGM). The EGM occurs in a unique textural setting in the rock, commonly forming spheroidal or irregular-shaped globules, herein called "snowballs", within the rock matrix. The snowballs are often protruded by aegirine and feldspar phenocrysts and contain swarms of fine aegirine and feldspar grains that often form spiral or swirling patterns within the snowball. Secondary ore minerals include REE carbonates, Y milarite, catapleiite and gaidonnayite that fill fractures and vesicles in the rock. Based on bulk-rock geochemical and Nd isotope data, and thermodynamic modelling of magma fractionation, the alkaline rocks of the region are interpreted to represent extrusive to hyperbyssal products of mantle-derived magma that ponded at mid-crustal levels (ca. 0.3 GPa) and underwent extensive fractionation under low-oxygen fugacity conditions. The high Na2O, peralkaline nature of the Toongi Deposit trachyte developed via extensive fractionation of an alkali olivine basalt parental magma initially in the mid-crust and subsequently at shallow levels (ca. 0.1 GPa). This extended fractionation under low fO2 and relatively low H2O-activity conditions limited volatile release and allowed build-up of rare metal contents to ore grades. We speculate that the ore minerals may have originally formed from rare metal-rich sodic-silicate melt that formed immiscible

  3. REE systematics in modern bottom sediments of the Caspian Sea and river deltas worldwide: Experience of comparison

    Science.gov (United States)

    Maslov, A. V.; Kozina, N. V.; Shevchenko, V. P.; Klyuvitkin, A. A.; Sapozhnikov, Ph. V.; Zavialov, P. O.

    2017-07-01

    The results of comparison of a number of main parameters of the chondrite-normalized REE distribution spectra in modern bottom, mainly pelitic, sediments of various sedimentary subsystems of the Caspian Sea and marginal filters of the Volga and Ural rivers with those characteristic of the pelitic fraction of modern bottom sediments of different river deltas worldwide are discussed. According to the features of the REE distribution spectra, as well as the ɛNd(0) values, it has been established that most samples of the Caspian bottom sediments are similar to those of large rivers and rivers, draining watersheds composed of sedimentary formations.

  4. Spectral response of REE{sup 3+} doped LaAlO{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Boronat, C.; Correcher, V. [CIEMAT, Av. Complutense 40, 28040 Madrid (Spain); Garcia G, J. [Museo Nacional de Ciencias Naturales - Consejo Superior de Investigaciones Cientificas, 28006 Madrid (Spain); Morales, A.; Zarate, J. [Universidad Michoacana de San Nicolas de Hidaldo, Instituto de Investigacion en Metalurgia y Materiales, Ciudad Universitaria, Morelia, Michoacan (Mexico); Rivera, T., E-mail: Cecilia.Boronat@ciemat.es [IPN, Ciudad de Mexico (Mexico)

    2016-10-15

    This paper reports on the preliminary results obtained from the cathodoluminescence (Cl) and thermoluminescence (Tl) properties of undoped LaAlO{sub 3} (LAO) and LaAlO{sub 3}: REE (REE=Dy{sup 3+}, Pr{sup 3+} and Eu{sup 3+}) to be potentially employed for dosimetric purposes. The samples were synthesized by a sol-gel process based on the Pechini 's method with a spray-drying technique and, subsequently, characterized by environmental scanning electron microscopy and energy dispersive X-ray analysis spectrometry. Cl spectra display sharp and narrow wavebands that could specifically be associated with structural (in the range of 300-450 nm) and point defects (from 450 to 800 nm). The observed wavebands could be assigned as follows: (i) 480 and 570 from the Dy-doped LAO should corresponding respectively to {sup 4}F{sub 9/2}→{sup 6}H{sub 15/2} and {sup 4}F{sub 9/2}→{sup 6}H{sub 13/2} transitions, (II) 490-638 from the Pr-doped LAO is linked to {sup 3}P{sub 0}→{sup 3}H{sub 4}, {sup 1}D{sub 2}→{sup 3}H{sub 4} transitions and (III) 590 and 620 where the dopant Eu{sup 3+} gives rise to {sup 5}D{sub 0}→{sup 7}F{sub 1} and {sup 5}D{sub 0}→{sup 7}F{sub 2} transitions and (IV) a UV-blue broad band is associated with NBOHC in undoped LAO. Such emissions are due to the presence of the 4f electrons of rare earth ions that are shielded by the outer 5s and 5p electrons, the intra-4f emission spectra of REE. Furthermore, the study performed on the Tl emission of LaAlO{sub 3}:Dy{sup 3+} displays (i) two maxima centred at 150 and 240 degrees Celsius (ratio 1:2) similarly to the Pr{sup 3+} doped sample but with 7:5 of ratio. And (II) the highest radiation sensitivity, allowing us to think on the potential use of this material for dosimetric purposes, however further works are necessary to confirm such assertion. (Author)

  5. Grow your own REE deposits: Novel observations from the soils of Southern Portugal

    Science.gov (United States)

    Hardy, Liam; Smith, Martin; Boyce, Adrian; McDonald, Alison; Heller, Shaun; Bamberger, Axel; Blum, Astrid; Hood, Leo

    2017-04-01

    Industrialised eucalyptus farming in Serra de Monchique has been well documented for its regional impacts on water flow, for its destructive centralisation of local economics (Jenkins, 1979) and for its derogatory impacts on local ecology (Brito, 1999) (Matias & Lamberts, 2011), it is another story of cash cropping for short term gain in an area of sensitive environmental balance which had previously been suitably subsistence farmed for some 700 years with no outside influence until the early 1950s (Jenkins, 1979). The farming has irreversibly changed local customs, soil and water systems, but formed new and intricate relationships between the troposol, oxisol and latosol formations and plants which have not previously been studied in this region in terms of soil geochemistry. During research in the region (as part of the SoS Rare/NERC-UK program) into metal and clay interactions in the troposol formations of Monchique, it was noted that rare earth elements (REEs) and other soluble ions were being mobilised in the upper half of the profiles by some seasonal cycle other than the natural meteoric input/leaching expected during classical lateritisation (Tardy, 1997). It was observed that some 40% of Fe and some 30% of Y were leaving the profile during wet season and concentrating at specific depths during dry seasons to a grade of some 160ppm Y and were thus, potentially viable as an economic resource of Heavy REEs. This PICO presentation discusses the proposed anthropogenic/biogenic mechanism for this concentration and how you too could potentially grow an economically viable REE enriched garden. References: Brito, J. G. (1999). Management strategies for conservation of the lizard Lacerta schreiberi in Portugal. Biological conservation, 311-319. Jenkins, R. (1979). The Road to Alto: An account of peasants, capitalists and their soil in the mountains of Southern Portugal. London: Pluto, ISBN: 0861040767. Matias, M., & Lamberts, P. (2011, May 26). Parliamentary

  6. The Obtaining of Nano Oxide Systems SiO2-REE with Alkoxide Technology

    Science.gov (United States)

    Amelina, Anna; Grinberg, Evgenii

    A lot of oxides systems with REE as dopants are used in catalytic processes in organic synthesis. They are very perspectives as thermostable coating in aerospace technics. These systems are usually based on silicon or aluminium oxides and doped with rare-earth elements. This systems can be produced by different methods. One of the most perspective of them is “sol-gel”-method with silicium, aluminium and rare-earth alkoxides as a precursor of doped silica and alumina, or their derivatives. Thus the obtaining of composite SiO _{2} - REE oxide materials by the hydrolysis doped with rare-earth elements was suggested. Some of alcoholate derivatives such as El(OR)n were used in this processes. The SiO _{2}- REE oxides were precipitated during the sol-gel process, where tetraethoxysilane (TEOS) as used as SiO _{2} sources. Also it is known that alkoxides of alkali metals, including lithium alkoxides, are widely used in industry and synthetic chemistry, as well as a source of lithium in various mixed oxide compositions, such as lithium niobate, lithium tantalate or lithium silicate. Therefore, we attempted to obtain the lithium silicate, which is also doped with rare-earth elements. Lithium silicate was obtained by alkaline hydrolysis of tetraethoxysilane with lithium alkoxide. Lithium alkoxide were synthesized by dissolving at metal in the corresponding alcohol are examined. The dependence of the rate of dissolving of the metal on the method of mixing of the reaction mixture and the degree of metal dispersion was investigated. The mathematical model of the process was composed and also optimization of process was carried out. Some oxide SiO _{2}, Al _{2}O _{3} and rare-earth nanostructured systems were obtained by sol-gel-method. The size of particle was determined by electron and X-ray spectroscopy and was in the range of 5 - 15 nm. Purity of this oxide examples for contaminating of heavy metals consists n.(1E-4...1E-5) wt%. Sols obtained by this method may be used

  7. Mobilization and mechanisms of retardation in the Oklo natural reactor zone 2 (Gabon)--inferences from U, REE, Zr, Mo and Se isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Bros, Regis; Hidaka, Hiroshi; Kamei, Gento; Ohnuki, Toshihiko

    2003-12-01

    Mineralogical and isotopic studies were carried out on the natural nuclear reaction zone 2 from the Oklo deposit to evaluate the mobility of several nuclear reaction products in response to the alteration of the reaction zone and to identify the mechanisms which could retard the transport of released radionuclides. To address these issues, in situ isotopic analyses by SHRIMP and a selective extraction procedure were performed to constrain the structural location of nuclear reaction products (exchangeable and non exchangeable) and their association with mineral phases. The distribution patterns of U, REE, Zr and Mo isotopes reveal that substantial amounts were released from the core and migrated through the hydrothermal alteration halo over metric distances, owing to uraninite dissolution and advective transport by hydrothermal solutions during and soon after criticality. The results emphasize the mobility of Zr at Oklo, this element being often considered as 'immobile' during water-rock interactions. The main output is the demonstration of the net effects of sorption and coprecipitation processes. Chlorite and to a lesser extent illite were found to have adsorbed significant amounts of U, REE, Zr (and probably Th) and less sorbing elements such as Mo. Coprecipitation of secondary UO{sub 2} and P-rich coffinite within the alteration halo is also an important means of retardation. The concentration of radionuclides released from the reactor were probably high and they display solubility limited transport behaviour. No retention effect was found for Se in the immediate vicinity of the reactor and this element may have moved farther from its source of production. These results have interesting implications for the evaluation of long-term containment of radionuclides. They provide a simple illustration of the performance of a clay barrier in the uptake of radionuclides by sorption onto clays and reincorporation in secondary U-minerals. This study also

  8. New Method for Probing Dark Energy using the Rees-Sciama Effect

    CERN Document Server

    Lee, Seokcheon

    2015-01-01

    The integrated Sachs-Wolfe (ISW) effect provides us the information of the time evolution of gravitational potential. The cross-correlation between the cosmic microwave background (CMB) and the large scale structure (LSS) is known as a promising way to extract the ISW effect. Compared to CMB, the matter fluctuation can grow non-linearly and this is represented in the gravitational potential. Compared to the linear ISW effect, this non-linear ISW effect known as the Rees-Sciama (RS) effect shows the unique behavior by changing the anti-correlated cross correlation between the CMB and the mass tracer into the positively correlated cross correlation. We show that the dependence of this flipping scale on dark energy models and it might be used as a new method to investigate dark energy models.

  9. Structural systematic and crystal chemistry of novel borates with REE, Pb, Sr, and alkali metals

    Energy Technology Data Exchange (ETDEWEB)

    Belokoneva, E.L. [Moscow State Univ., Moscow (Russian Federation). Dept. of Crystallography and Crystal Chemistry

    2013-11-01

    Crystal structures of novel borates with REE, Pb, Sr and alkali metals were analyzed using classical fundamental buildings blocks approach. It is demonstrated that hexa-, penta-, tetra-, tri- and diborates subdivisions in systematic are real families of structures with the common peculiarities. According to the symmetrical way and the degree of FBB condensation structural-generic rows exist in every of subdivisions. Mega- or polyborates subdivision is valid for the structures with the different types of simplest FBB. In all new complex borates it is possible to separate FBB of equal or different types which are presented in isolated form or are connected into chains, layers or frameworks, and to find unexpected correlation between structures. The possibility to recognize and to visualize in this approach the polarity or non-polarity of the structural units and correspondingly the polarity or nonpolarity of the structures in the whole is very important for the conclusion on structure-properties relation. (orig.)

  10. A Study on sediment sources in a small watershed by using REE tracer method

    Institute of Scientific and Technical Information of China (English)

    石辉; 田均良; 刘普灵; 周佩华

    1997-01-01

    In simulation experiments, rare earth element (REE) tracer method was first used to sludy the sources of sediment yield in a small watershed. The experimental results have shown that the chief parts of sediment sources are constantly changing with the development of gullies. The cutting erosion plays a major role in the primary stage of watershed development. Slope erosion intensity increased gradually with gully development of the watershed, while gully erosion intensity decreased. Similar process was also observed in an individual rainfall. The simulation experiments have shown that the method can satisfactorily interpret the origins of sediment yield of a small watershed on an effective way. The simulation experiments have also provided basic information for field researches.

  11. Carbonatites of the World, Explored Deposits of Nb and REE - Database and Grade and Tonnage Models

    Science.gov (United States)

    Berger, Vladimir I.; Singer, Donald A.; Orris, Greta J.

    2009-01-01

    This report is based on published tonnage and grade data on 58 Nb- and rare-earth-element (REE)-bearing carbonatite deposits that are mostly well explored and are partially mined or contain resources of these elements. The deposits represent only a part of the known 527 carbonatites around the world, but they are characterized by reliable quantitative data on ore tonnages and grades of niobium and REE. Grade and tonnage models are an important component of mineral resource assessments. Carbonatites present one of the main natural sources of niobium and rare-earth elements, the economic importance of which grows consistently. A purpose of this report is to update earlier publications. New information about known deposits, as well as data on new deposits published during the last decade, are incorporated in the present paper. The compiled database (appendix 1; linked to right) contains 60 explored Nb- and REE-bearing carbonatite deposits - resources of 55 of these deposits are taken from publications. In the present updated grade-tonnage model we have added 24 deposits comparing with the previous model of Singer (1998). Resources of most deposits are residuum ores in the upper part of carbonatite bodies. Mineral-deposit models are important in exploration planning and quantitative resource assessments for two reasons: (1) grades and tonnages among deposit types vary significantly, and (2) deposits of different types are present in distinct geologic settings that can be identified from geologic maps. Mineral-deposit models combine the diverse geoscience information on geology, mineral occurrences, geophysics, and geochemistry used in resource assessments and mineral exploration. Globally based deposit models allow recognition of important features and demonstrate how common different features are. Well-designed deposit models allow geologists to deduce possible mineral-deposit types in a given geologic environment, and the grade and tonnage models allow economists to

  12. A synthesis of mineralization styles with an integrated genetic model of carbonatite-syenite-hosted REE deposits in the Cenozoic Mianning-Dechang REE metallogenic belt, the eastern Tibetan Plateau, southwestern China

    Science.gov (United States)

    Liu, Yan; Hou, Zengqian

    2017-04-01

    The Cenozoic Mianning-Dechang (MD) rare earth element (REE) belt in eastern Tibet is an important source of light REE in southwest China. The belt is 270 km long and 15 km wide. The total REE resources are >3 Mt of light rare earth oxides (REO), including 3.17 Mt of REO at Maoniuping (average grade = 2.95 wt.%), 81,556 t at Dalucao (average grade = 5.21 wt.%), 0.1 Mt at Muluozhai (average grade = 3.97 wt.%), and 5764 t of REO at Lizhuang (average grade = 2.38 wt.%). Recent results from detailed geological surveys, and studies of petrographic features, ore-forming ages, ore forming conditions, and wallrock alteration are synthesized in this paper. REE mineralization within this belt is associated with carbonatite-syenite complexes, with syenites occurring as stocks intruded by carbonatitic sills or dikes. The mineralization is present as complex vein systems that contain veinlet, stringer, stockwork, and brecciated pipe type mineralization. Carbonatites in these carbonatite-related REE deposits (CARDs) are extremely rich in light REEs, Sr (>5000 ppm), and Ba (>1000 ppm), and have low Sr/Ba and high Ba/Th ratios, and radiogenic Sr-Nd isotopic compositions. These fertile magmas, which may lead to the formation of REE deposits, were generated by the partial melting of sub-continental lithospheric mantle (SCLM) that was metasomatized by REE- and CO2-rich fluids derived from subducted marine sediments. We suggest that this refertilization occurred along cratonic margins and, in particular, at a convergent margin where small-volume carbonatitic melts ascended along trans-lithospheric faults and transported REEs into the overlying crust, leading to the formation of the CARDs. The formation of fertile carbonatites requires a thick lithosphere and/or high pressures (>25 kbar), a metasomatized and enriched mantle source, and favorable pathways for magma to ascend into the overlying crust where REE-rich fluids exsolve from cooling magma. The optimal combination of these three

  13. Preservation of REE and Fe isotopes in altered stromatolites and the paleo-environmental record

    Science.gov (United States)

    Nies, S. M.; Shapiro, R. S.; Lalonde, S.

    2015-12-01

    Geochemical proxies are increasingly being used to unravel ancient ecosystems and environmental perturbations back to the earliest rock record on Earth. Along with more traditional fossils (stromatolites) and other biosignatures (e.g., lipids), the geochemical record is used specifically to evaluate biogenecity and to understand oxygenation of the atmosphere and ocean in the Archean and Paleoproterozoic. However, the effects of diagenesis, metamorphism, and other modes of secondary alteration are still poorly constrained, particularly as technological advances allow us to expand farther across the periodic table. Our study focused on the robustness and preservation of rare earth element (REE) and Fe isotope compositions of two stromatolitic units that have undergone contact and regional metamorphism. 18 samples were collected from cores, open pit mines, and field locations in Minnesota and Ontario from silicified iron formation (Biwabik-Gunflint formations). The samples were carefully constrained to one of two meter-scale stromatolitic units. Metamorphic grade ranged from essentially unmetamorphosed through prehnite-pumpellyite up to amphibolite (fayalite+hypersthene). Samples were also collected that represented deep secondary weathering, likely related to Cretaceous climatic extremes. Polished samples were first analyzed by electron microprobe and selected samples were further analyzed via laser ablation HR-ICP-MS to constrain trace element (n=13) and Fe isotopic variations (n=8). Preliminary results indicate that transition metal concentrations are surprisingly resilient to high-temperature metamorphic recrystallization. REE concentrations were analyzed in individual iron oxide grains, with full resolution (La to Lu) achieved for some samples and partial resolution (La to Nd) achieved for all samples. Core samples exhibited a relatively stable positive Ce anomaly occurring from low to extremely high alteration. Outcrop and mine samples indicate a shift from a

  14. Natural Metasomatism of Monazite and Xenotime: a Guide to Define Optimal Orthophosphate Leaching Approaches during REE Extraction.

    Science.gov (United States)

    Thibault, Y.; Gamage McEvoy, J.

    2016-12-01

    Numerous studies have documented the redistribution of the LREE, the HREE (+Y) and the actinides within the REE-orthophosphates (monazite, xenotime) through natural metamorphic processes. Supporting experimental investigations on the role of alkali-bearing fluids during metasomatism of monazite have demonstrated that partial replacement by an isostructural huttonite (ThSiO4)-enriched phase, as well as preferential partitioning of the HREE (+Y) in solution can be significant for specific fluid compositions.1-3 In the context of economic REE extraction, the refractory nature of the orthophosphates usually prescribes an initial decomposition in alkali hydroxide solution with the production of crystalline REE(OH)3 and water-soluble Na3PO4. The lack of selectivity of such dissolution processes leads to downstream hydrometallurgical challenges associated with efficient separation of the different REE and safe removal of the radioactive contaminants (e.g. Th, U). Consequently, the goal of this study is to investigate experimentally if, in light of the fluid-induced elemental redistribution resulting from natural metasomatism, the alkali-bearing solution properties during monazite and xenotime leaching can be modified to promote early separation of the actinides, the LREE and the HREE. Controlled dissolution experiments are performed using natural single crystals of REE-orthophosphates as well as synthetic analogues produced along relevant single and coupled substitutions (LREE3+↔HREE3+, Th4+Ca2+↔2REE3+, Th4+Si4+↔REE3+P5+). The chemical and structural properties of the experimental products are characterized by micro-X-ray diffraction, electron probe X-ray microanalysis, electron backscatter diffraction and high-resolution transmission electron microscopy. The results will be presented and discussed with an emphasis on the potential of identifying a selective fractional dissolution process with preferential sequestration of Th in a residual refractory orthophosphate

  15. Source of ore-forming substances and theoretical problems of metallogeny relevant to the Bayan Obo Fe-REE ore deposits in Inner Mongolia,China

    Institute of Scientific and Technical Information of China (English)

    曹荣龙; 朱寿华; 王俊文

    1995-01-01

    The source of rare earth elements (REE) ore-forming substances is identified to be extremelydistinct from that of iron ores.The Bayan Obo Fe-REE ore deposits were generated by a composite processof both crustal and mantle source mineralization.The original iron bodies are of a sedimentary deposit fromsupergenesis,while the REE ores have been formed by mantle fluid metasomatism superimposed upon thepre-existing iron bodies.It is believed that the REE ore deposit would be controlled by intracontinental hotspot.The H8 dolomite in mine regions belongs to normal sedimentary carbonate rock,its C and O isotopiccomposition rules out the possibility comparable with magrnatic carbonatite.The Sm-Nd isochrons of separatedREE minerals have shown two REE peak mineralization periods:early-middle Proterozoic (1 700 Ma±480 Ma) andCaledonia (424-402 Ma).

  16. Closure Temperature in Cooling Bi-Mineralic Systems With Application to REE-in-Two-Pyroxene Thermometer

    Science.gov (United States)

    Yao, L.; Liang, Y.

    2013-12-01

    Closure temperature is an important concept to many diffusion related problems involving cooling. The basic idea and formulation were outlined in the seminal work of Dodson for cooling mono-mineralic systems [1, 2]. The Dodson's equation has been widely used to calculate closure temperatures for igneous and metamorphic rocks that usually contain more than one mineral. The purpose of this study is to systematically examine closure temperatures in cooling bi-mineralic systems. This study is also motivated by our quest for the physical meaning of temperatures derived from the REE-in-two-pyroxene thermometer that is based on temperature-dependent REE partitioning between coexisting orthopyroxene (opx) and clinopyroxene (cpx) in mafic and ultramafic rocks [3]. To better understand closure temperatures and their relations to the REE-in-two-pyroxene thermometer, we conduct numerical simulations of diffusive re-equilibration of trace elements between two coexisting minerals under prescribed cooling using temperature-dependent diffusion coefficient and partition coefficient. Following Dodson's approach for mono-mineralic systems, we define the closure temperature of a trace element in cooling bi-mineralic systems using two methods: (1) by following the evolution of average concentration of the trace element in each mineral; (2) by tracing the variation of an effective partition coefficient (ratio of the average concentrations between the two minerals). Closure temperatures calculated using the two definitions are identical for a wide range of grain sizes and cooling rates. Additional simulations for a range of temperature-dependent partition coefficients and diffusion coefficients reveal that in addition to parameters introduced in Dodson's equation (pre-exponential factor D0, activation energy E, mineral grain size, and cooling rate), temperature-dependent partition coefficients are also important in determining the closure temperature for the bi-mineralic systems. Our

  17. Status epilepticus: Refractory and super-refractory.

    Science.gov (United States)

    Dubey, Deepanshu; Kalita, Jayantee; Misra, Usha K

    2017-01-01

    Status epilepticus (SE) is an important neurological emergency. It is defined as seizures lasting for 5 minutes or more or recurrent seizures without recovery of consciousness to baseline between the attacks. Refractory SE (RSE) is defined as SE persisting despite sufficient dose of benzodiazepines and at least one antiepileptic drug (AED), irrespective of time. Super refractory SE (SRSE) is defined as SE that continues for 24 hours or more after the use of anesthetic therapy, including cases that recur on weaning of the anesthestic agent. RSE occurs in 23%-48% of the patients and SRSE in approximately 22% of the patients with SE. In general, RSE occurs in patients with new-onset seizures rather than in patients with chronic epilepsy. The etiology of RSE in developing countries is dominated by central nervous system (CNS) infections and head injury compared to stroke and drug withdrawal in the developed countries. The treatment of RSE and SRSE is not evidence based. Following benzodiazepines, the second line antiepileptic drugs include sodium valproate, phenytoin, levetiracetam, and anesthetic drugs such as midazolam, phenobarbital, and propofol. Most intravenous anesthetic drugs produce hypotension and respiratory suppression; therefore, patients with RSE are managed in intensive care units (ICUs). In RSE patients, electroencephalogram (EEG) burst suppression with interburst interval of 2-20 s or even flat EEG has been tried. Recently, concerns have been raised on the safety of burst suppression in RSE and SRSE. The paucity of ICUs in developing countries limits the use of these management protocols. There is a need to explore intravenous AEDs with safer cardiovascular and respiratory profile for the management of SE.

  18. The distribution and composition of REE-bearing minerals in placers of the Atlantic and Gulf coastal plains, USA

    Science.gov (United States)

    Bern, Carleton; Shah, Anjana K.; Benzel, William M.; Lowers, Heather

    2016-01-01

    Rare earth element (REE) resources are currently of great interest because of their importance as raw materials for high-technology manufacturing. The REE-phosphates monazite (light REE enriched) and xenotime (heavy REE enriched) resist weathering and can accumulate in placer deposits as part of the heavy mineral assemblage. The Atlantic and Gulf coastal plains of the southeastern United States are known to host heavy mineral deposits with economic concentrations of zircon, ilmenite and rutile. This study provides a perspective on the distribution and composition of REE phosphate minerals in the region. The elemental chemistry and mineralogy of sands and associated heavy-mineral assemblages from new and archived sediment samples across the coastal plains are examined, along with phase-specific compositions of monazite, xenotime and zircon. Both monazite and xenotime are present across the coastal plains. The phase-specific compositions allow monazite content to be estimated using La as a geochemical proxy. Similarly, both Y and Yb are geochemical proxies for xenotime, but their additional presence in zircon and monazite require a correction to prevent overestimation of xenotime content. Applying this correction, maps of monazite and xenotime content across the coastal plains were generated using sample coverage from the National Geochemical Database (NGS) and National Uranium Resource Evaluation (NURE). The NGS and NURE approach of sampling stream sediments in small watersheds links samples to nearby lithologies. The results show an approximately 40 km-wide band of primarily Cretaceous, marine sediments bordering the Piedmont province from North Carolina to Alabama in which monazite and xenotime content are relatively high (up to 4.4 wt. % in < 150 μm bulk sediment). Strong correlations between concentrations of the two phases were found, with estimated monazite:xenotime ratios ranging approximately 6:1 to 12:1 depending upon the dataset analyzed. From a resource

  19. An Experimental Study on the Effects of Microbes on the Migration and Accumulation of REE in the Weathering Crust of Granite

    Institute of Scientific and Technical Information of China (English)

    陈炳辉; 王智美; 等

    2000-01-01

    Microbes were cultured and identified from the saples collected at various depths in 4 weathering profiles of REE-bearing granites in Gonghe,Guangdong,The microbes were found existing at the depth of 0-5m in all the profiles.The main microbes include coccus (Staphylococcus,Streptococcus),bacillus(Bacillus,Clostridium and Escherichia Coli),actinmyces and fungi(Saccharomycete,Penicillium,Fusarium,Aspergillus Aiger and Mucor),The number of colonies decreases downwards in the profiles.Experimental studies show that all the microbes used in the experiment can accelerate downward migation of REE in the experimental tubes.,The ability to accelerate the migration of REE decreases in a sequence of fungi→actinomyces→acillus→coccus.The microbes can change the modes of occurrence of REE in the weathering crust.The coccus,bacillus and actinomyces can increase the amounts of REE in ion state,whereas the fungi have a stronger ability to from organic compounding REE and accumulate REE than the bacteria do.

  20. Recombinant cancer vaccines and new vaccine targets. Interview by Jenaid Rees.

    Science.gov (United States)

    Schlom, Jeffrey

    2013-10-01

    Interview by Jenaid Rees, Commissioning Editor Jeffrey Schlom obtained his PhD from Rutgers University (NJ, USA). After obtaining his PhD, he worked at Columbia University (NY, USA) before moving in 1973 to the National Cancer Institute, National Institutes of Health (MD, USA). Since then he has served as the Chief of several sections, including his present position as the Chief of the Laboratory of Tumor Immunology and Biology in the Center for Cancer Research which he has held for the past 30 years. During this period, he has worked as an Adjunct Professor at George Washington University (Washington, DC, USA), served on the Editorial Board of several journals and holds membership in a number of committees. He holds over 30 patents and patent applications in the areas of vaccines, tumor antigens and monoclonal antibodies and has received honors and awards throughout his career. Jeffrey Schlom has been involved in translational research involving the immunotherapy of a range of carcinomas and predominantly works in the areas of tumor immunology, mechanisms of tumor cell-immune cell interactions and immune mechanisms. He has recently been working on the design and characterization of recombinant vaccines for cancer therapy.

  1. Synthetic and natural Nakhla pyroxenes: Parent melt composition and REE partition coefficients

    Science.gov (United States)

    Mckay, G.; Le, L.; Wagstaff, J.

    1994-01-01

    Nakhla is one of the SNC meteorites, generally believed to be of martian origin. It is composed mainly of cumulus augite, in which primary igneous zoning is apparently preserved, and which serves as a recorder of the composition of Nakhla's parent melt and the conditions under which it crystallized. Knowledge of the composition and petrogenesis of this parent melt may help unravel Nakhla's relationship to the other SNC's, and provide clues to martian petrogenesis in general. This abstract reports new results of an ongoing study in which we are (1) comparing the major and minor element compositions of synthetic pyroxenes crystallized from various proposed parent melt compositions with those in Nakhla pyroxene to constrain the composition of the parent melt, and (2) measuring minor and trace element partition coefficients, particularly those of the REE, in order to obtain the most applicable D values with which to invert the natural pyroxene compositions to obtain the trace element composition of the parent melt. Results suggest that recent estimates of Nakhla's parent melt composition are too aluminous, and that mafic or ultramafic melts are more likely candidates.

  2. Partition coefficients of Hf, Zr, and REE between phenocrysts and groundmasses

    Science.gov (United States)

    Fujimaki, H.; Tatsumoto, M.; Aoki, K.-I.

    1984-01-01

    Partition coefficients of Hf, Zr, and REE between olivine, orthopyroxene, clinopyroxene, plagioclase, garnet, amphibole, ilmenite, phlogopite, and liquid are presented. Samples consist of megacrysts in kimberlite, phenocrysts in alkaline basalts, tholeiitic basalts and andesitic to dacitic rocks, and synthetic garnet and clinopyroxene in Hawaiian tholeiites. The Hf-Lu and Zr-Lu elemental fractionations are as large as the Lu-Sm or Lu-Nd fractionation. The Hf and Zr partition coefficients between mafic phenocrysts and liquids are smaller than the Lu partition coefficients, but are similar to the Nd or Sm partition coefficients. The Hf and Zr partition coefficients between ilmenite, phlogopite, and liquid are larger than the Lu partition coefficients for these minerals and their corresponding liquids. The Hf-Zr elemental fractionation does not occur except for extreme fractionation involving Zr-minerals and extremely low fO2. These data have an important bearing on chronological and petrogenetic tracer studies involving the Lu-Hf isotopic system.

  3. Modification of REE distribution of ordinary chondrites from Atacama (Chile) and Lut (Iran) hot deserts: Insights into the chemical weathering of meteorites

    Science.gov (United States)

    Pourkhorsandi, Hamed; D'Orazio, Massimo; Rochette, Pierre; Valenzuela, Millarca; Gattacceca, Jérôme; Mirnejad, Hassan; Sutter, Brad; Hutzler, Aurore; Aboulahris, Maria

    2017-09-01

    The behavior of rare earth elements (REEs) during hot desert weathering of meteorites is investigated. Ordinary chondrites (OCs) from Atacama (Chile) and Lut (Iran) deserts show different variations in REE composition during this process. Inductively coupled plasma-mass spectrometry (ICP-MS) data reveal that hot desert OCs tend to show elevated light REE concentrations, relative to OC falls. Chondrites from Atacama are by far the most enriched in REEs and this enrichment is not necessarily related to their degree of weathering. Positive Ce anomaly of fresh chondrites from Atacama and the successive formation of a negative Ce anomaly with the addition of trivalent REEs are similar to the process reported from Antarctic eucrites. In addition to REEs, Sr and Ba also show different concentrations when comparing OCs from different hot deserts. The stability of Atacama surfaces and the associated old terrestrial ages of meteorites from this region give the samples the necessary time to interact with the terrestrial environment and to be chemically modified. Higher REE contents and LREE-enriched composition are evidence of contamination by terrestrial soil. Despite their low degrees of weathering, special care must be taken into account while working on the REE composition of Atacama meteorites for cosmochemistry applications. In contrast, chondrites from the Lut desert show lower degrees of REE modification, despite significant weathering signed by Sr content. This is explained by the relatively rapid weathering rate of the meteorites occurring in the Lut desert, which hampers the penetration of terrestrial material by forming voluminous Fe oxide/oxyhydroxides shortly after the meteorite fall.

  4. Major element, REE, and Pb, Nd and Sr isotopic geochemistry of Cenozoic volcanic rocks of eastern China: implications for their origin from suboceanic-type mantle reservoirs

    Science.gov (United States)

    Basu, A.R.; Wang, Junwen; Huang, Wankang; Xie, Guanghong; Tatsumoto, M.

    1991-01-01

    Major- and rare-earth-element (REE) concentrations and UThPb, SmNd, and RbSr isotope systematics are reported for Cenozoic volcanic rocks from northeastern and eastern China. These volcanic rocks, characteristically lacking the calc-alkaline suite of orogenic belts, were emplaced in a rift system which formed in response to the subduction of the western Pacific plate beneath the eastern Asiatic continental margin. The rocks sampled range from basanite and alkali olivine basalt, through olivine tholeiite and quartz tholeiite, to potassic basalts, alkali trachytes, pantellerite, and limburgite. These rock suites represent the volcanic centers of Datong, Hanobar, Kuandian, Changbaishan and Wudalianchi in northeastern China, and Mingxi in the Fujian Province of eastern China. The major-element and REE geochemistry is characteristic of each volcanic suite broadly evolving through cogenetic magmatic processes. Some of the outstanding features of the isotopic correlation arrays are as follows: (1) NdSr shows an anticorrelation within the field of ocean island basalts, extending from the MORB end-member to an enriched, time-averaged high Rb Sr and Nd Sr end-member (EM1), (2) SrPb also shows an anticorrelation, similar to that of Hawaiian and walvis Ridge basalts, (3) NdPb shows a positive correlation, and (4) the 207Pb 204Pb vs 206Pb 204Pb plot shows linear arrays parallel to the general trend (NHRL) for MORB on both sides of the geochron, although in the 208Pb 204Pb vs 206Pb 204Pb plot the linear array is significantly displaced above the NHRL in a pattern similar to that of the oceanic island basalts that show the Dupal signatures. In all isotope correlation patterns, the data arrays define two different mantle components-a MORB-like component and an enriched mantle component. The isotopic data presented here clearly demonstrate the existence of Dupal compositions in the sources of the continental volcanic rocks of eastern China. We suggest that the subcontinental mantle

  5. Age-Dependent Changes in Resting Energy Expenditure (REE: Insights from Detailed Body Composition Analysis in Normal and Overweight Healthy Caucasians

    Directory of Open Access Journals (Sweden)

    Corinna Geisler

    2016-06-01

    Full Text Available Age-related changes in organ and tissue masses may add to changes in the relationship between resting energy expenditure (REE and fat free mass (FFM in normal and overweight healthy Caucasians. Secondary analysis using cross-sectional data of 714 healthy normal and overweight Caucasian subjects (age 18–83 years with comprehensive information on FFM, organ and tissue masses (as assessed by magnetic resonance imaging (MRI, body density (as assessed by Air Displacement Plethysmography (ADP and hydration (as assessed by deuterium dilution (D2O and REE (as assessed by indirect calorimetry. High metabolic rate organs (HMR summarized brain, heart, liver and kidney masses. Ratios of HMR organs and muscle mass (MM in relation to FFM were considered. REE was calculated (REEc using organ and tissue masses times their specific metabolic rates. REE, FFM, specific metabolic rates, the REE-FFM relationship, HOMA, CRP, and thyroid hormone levels change with age. The age-related decrease in FFM explained 59.7% of decreases in REE. Mean residuals of the REE-FFM association were positive in young adults but became negative in older subjects. When compared to young adults, proportions of MM to FFM decreased with age, whereas contributions of liver and heart did not differ between age groups. HOMA, TSH and inflammation (plasma CRP-levels explained 4.2%, 2.0% and 1.4% of the variance in the REE-FFM residuals, but age and plasma T3-levels had no effects. HMR to FFM and MM to FFM ratios together added 11.8% on to the variance of REE-FFM residuals. Differences between REE and REEc increased with age, suggesting age-related changes in specific metabolic rates of organs and tissues. This bias was partly explained by plasmaT3-levels. Age-related changes in REE are explained by (i decreases in fat free mass; (ii a decrease in the contributions of organ and muscle masses to FFM; and (iii decreases in specific organ and tissue metabolic rates. Age-dependent changes in the

  6. Origin of REE-rich ferrocarbonatites in southern Siberia (Russia): implications based on melt and fluid inclusions

    Science.gov (United States)

    Prokopyev, Ilya R.; Borisenko, Alexander S.; Borovikov, Andrey A.; Pavlova, Galina G.

    2016-12-01

    Fe-rich carbonatites with a mineral assemblage of ankerite-calcite or siderite are widespread in southern Siberia, Russia. The siderite carbonatites are associated with F-Ba-Sr-REE mineralization and have a 40Ar/39Ar age of 117.2 ± 1.3 Ma. Melt and fluid inclusions suggest that the carbonatites formed from volatile-rich alkali- and chloride-bearing carbonate melts. Ankerite-calcite carbonatites formed from carbonatite melt at a temperature of more than 790 °C. The ferrocarbonatites (the second phase of carbonatite intrusion) formed from a sulfate-carbonate-chloride fluid phase (brine-melt) at >650 °C and ≥360 MPa. The brine-melt fluid phase had high concentrations of Fe and LREEs. A subsequent hydrothermal overprint contributed to the formation of economically important barite-Sr-fluorite-REE mineralization in polymict siderite breccia.

  7. Rare-earth element patterns in conodont albid crowns: Evidence for massive inputs of volcanic ash during the latest Permian biocrisis?

    Science.gov (United States)

    Zhao, Laishi; Chen, Zhong-Qiang; Algeo, Thomas J.; Chen, Jianbo; Chen, Yonglin; Tong, Jinnan; Gao, Shan; Zhou, Lian; Hu, Zhaochu; Liu, Yongsheng

    2013-06-01

    Rare-earth element (REE) profiles were generated from conodont bioapatite for two Permian-Triassic boundary sections in South China (Meishan and Daxiakou) in order to investigate environmental changes following the latest Permian mass extinction (LPME). REE concentrations were measured in albid crowns, the conodont histology that is densest and least susceptible to diagenetic alteration, in an effort to recover seawater REE signatures. However, an analysis of REE sources demonstrated that 80-100% of REEs in the study samples were derived from siliciclastic sources, presumably the abundant clay minerals present in the study sections. Interval I (pre-LPME) exhibited lower ΣREE concentrations and distinctly different REE distribution patterns than Intervals II (syn-LPME) and III (post-LPME) of the study sections. REE "fingerprinting" suggests that the latter two intervals contain a large fraction of REEs derived from volcanic clays, characterized by low Eu/Eu* and LaN/YbN and high Th/La ratios. The presence of volcanically derived REEs in post-LPME Interval III indicates that volcanic eruptions continued to spew ash for an extended interval following the boundary crisis or, perhaps more likely, that substantial ash deposits that fell on landmasses during the LPME were slowly eroded and transported to the marine environment. The most probable source of this volcanic ash is the Siberian Traps magmatic province. Ce/Ce* ratios of 0.8-1.0 around the LPME may reflect suboxic to anoxic seawater conditions, although it is uncertain whether Ce in the study sections is mainly of hydrogenous or detrital origin.

  8. Mineralogy and crystallization history of a highly differentiated REE-enriched hypabyssal rhyolite: Round Top laccolith, Trans-Pecos, Texas

    Science.gov (United States)

    O'Neill, L. Christine; Elliott, Brent A.; Kyle, J. Richard

    2017-09-01

    The Round Top hypabyssal rhyolite laccolith is a highly evolved magmatic system, enriched in incompatible elements including REE [Rare Earth Element(s)], U, Be, and F. The Round Top intrusion is part of a series of Paleogene intrusions emplaced as the Sierra Blanca Complex. These intrusions are situated within long-lived, complex tectonic regimes that have been subjected to regional compression and subduction, punctuated by extensional bimodal volcanism. The enrichment in the rhyolite that comprises Round Top is the result of the prolonged removal of compatible elements from the source magma chamber through the emplacement of earlier magmatic events. With the emplacement of each sequential laccolith, the F-rich source magma became more enriched in incompatible elements, with increasing HREE [Heavy Rare Earth Elements(s)] concentrations. The emplacement of Round Top as a laccolith (versus that of an extrusive rhyolitic flow) facilitated the retention of the volatile-rich vapor phase within the magma, forming ubiquitous REE-bearing minerals, mainly yttrofluorite and yttrocerite. The high temperature mineral-vapor phase alteration of the feldspar groundmass was essential to the formation of REE minerals, where the pervasive open pore space was occupied by the late-crystallizing minerals. These late-forming REE-bearing minerals also occur as crystals associated with other accessory and trace phases, as inclusions within other phases, along grain boundaries, and along fractures and within voids. The rhyolite at Round Top and other laccolith intrusions in the Sierra Blanca Complex represent a new sub-type of magmatic rare earth element hosting system.

  9. On L^1-Convergence Of Rees-Stanojević's Sums With Coefficients From The Class K

    Directory of Open Access Journals (Sweden)

    Xhevat Z. Krasniqi

    2010-12-01

    Full Text Available In this paper are considered the modified cosine sums introduced by Rees and Stanojević  with coefficients from the class K. In addition, it is proved that the condition $\\lim_{n\\to \\infty}|a_{n+1}|\\log n= 0$ is a necessary and sufficient condition for the $L^{1}$-convergence of the cosine series. Also, an open problem about $L^{1}$-convergence for the $r-th$ derivative  of the cosine series is presented.

  10. On the estimation and detection of the Rees-Sciama effect

    Science.gov (United States)

    Fullana, M. J.; Arnau, J. V.; Thacker, R. J.; Couchman, H. M. P.; Sáez, D.

    2017-02-01

    Maps of the Rees-Sciama (RS) effect are simulated using the parallel N-body code, HYDRA, and a run-time ray-tracing procedure. A method designed for the analysis of small, square cosmic microwave background (CMB) maps is applied to our RS maps. Each of these techniques has been tested and successfully applied in previous papers. Within a range of angular scales, our estimate of the RS angular power spectrum due to variations in the peculiar gravitational potential on scales smaller than 42/h megaparsecs is shown to be robust. An exhaustive study of the redshifts and spatial scales relevant for the production of RS anisotropy is developed for the first time. Results from this study demonstrate that (i) to estimate the full integrated RS effect, the initial redshift for the calculations (integration) must be greater than 25, (ii) the effect produced by strongly non-linear structures is very small and peaks at angular scales close to 4.3 arcmin, and (iii) the RS anisotropy cannot be detected either directly-in temperature CMB maps-or by looking for cross-correlations between these maps and tracers of the dark matter distribution. To estimate the RS effect produced by scales larger than 42/h megaparsecs, where the density contrast is not strongly non-linear, high accuracy N-body simulations appear unnecessary. Simulations based on approximations such as the Zel'dovich approximation and adhesion prescriptions, for example, may be adequate. These results can be used to guide the design of future RS simulations.

  11. Distribution of REEs and yttrium among major geochemical phases of marine Fe–Mn-oxides: Comparative study between hydrogenous and hydrothermal deposits

    Digital Repository Service at National Institute of Oceanography (India)

    SuryaPrakash, L.; Ray, D.; Paropkari, A.L.; Mudholkar, A.V.; Satyanarayanan, M.; Sreenivas, B.; Chandrasekharam, D.; Kota, D.; KameshRaju, K.A.; Kaisary, S.; Balaram, V.; Gurav, T.

    in hydrothermal oxides is described in terms of co-precipitation and adsorption of their halide complexes and available free ions in hydrothermal solutions. Instead, adsorption of major carbonate species from seawater primarily regulates the partitioning of REEs...

  12. Partition coefficients for REE between garnets and liquids - Implications of non-Henry's Law behaviour for models of basalt origin and evolution

    Science.gov (United States)

    Harrison, W. J.

    1981-01-01

    An experimental investigation of Ce, Sm and Tm rare earth element (REE) partition coefficients between coexisting garnets (both natural and synthetic) and hydrous liquids shows that Henry's Law may not be obeyed over a range of REE concentrations of geological relevance. Systematic differences between the three REE and the two garnet compositions may be explained in terms of the differences between REE ionic radii and those of the dodecahedral site into which they substitute, substantiating the Harrison and Wood (1980) model of altervalent substitution. Model calculations demonstrate that significant variation can occur in the rare earth contents of melts produced from a garnet lherzolite, if Henry's Law partition coefficients do not apply for the garnet phase.

  13. Partition coefficients for REE between garnets and liquids - Implications of non-Henry's Law behaviour for models of basalt origin and evolution

    Science.gov (United States)

    Harrison, W. J.

    1981-01-01

    An experimental investigation of Ce, Sm and Tm rare earth element (REE) partition coefficients between coexisting garnets (both natural and synthetic) and hydrous liquids shows that Henry's Law may not be obeyed over a range of REE concentrations of geological relevance. Systematic differences between the three REE and the two garnet compositions may be explained in terms of the differences between REE ionic radii and those of the dodecahedral site into which they substitute, substantiating the Harrison and Wood (1980) model of altervalent substitution. Model calculations demonstrate that significant variation can occur in the rare earth contents of melts produced from a garnet lherzolite, if Henry's Law partition coefficients do not apply for the garnet phase.

  14. Identification of hydrologic and geochemical pathways using high frequency sampling, REE aqueous sampling and soil characterization at Koiliaris Critical Zone Observatory, Crete

    Energy Technology Data Exchange (ETDEWEB)

    Moraetis, Daniel, E-mail: moraetis@mred.tuc.gr [Department of Environmental Engineering, Technical University of Crete, 73100 Chania (Greece); Stamati, Fotini; Kotronakis, Manolis; Fragia, Tasoula; Paranychnianakis, Nikolaos; Nikolaidis, Nikolaos P. [Department of Environmental Engineering, Technical University of Crete, 73100 Chania (Greece)

    2011-06-15

    Highlights: > Identification of hydrological and geochemical pathways within a complex watershed. > Water increased N-NO{sub 3} concentration and E.C. values during flash flood events. > Soil degradation and impact on water infiltration within the Koiliaris watershed. > Analysis of Rare Earth Elements in water bodies for identification of karstic water. - Abstract: Koiliaris River watershed is a Critical Zone Observatory that represents severely degraded soils due to intensive agricultural activities and biophysical factors. It has typical Mediterranean soils under the imminent threat of desertification which is expected to intensify due to projected climate change. High frequency hydro-chemical monitoring with targeted sampling for Rare Earth Elements (REE) analysis of different water bodies and geochemical characterization of soils were used for the identification of hydrologic and geochemical pathways. The high frequency monitoring of water chemical data highlighted the chemical alterations of water in Koiliaris River during flash flood events. Soil physical and chemical characterization surveys were used to identify erodibility patterns within the watershed and the influence of soils on surface and ground water chemistry. The methodology presented can be used to identify the impacts of degraded soils to surface and ground water quality as well as in the design of methods to minimize the impacts of land use practices.

  15. Analysis of Rare Earth Elements (REE) in vein quartz and quartz-sandstone host rock in the Zhelannoe high purity quartz deposit, Russia

    Science.gov (United States)

    Zemskova, Marina; Prokofiev, Vsevolod; Bychkov, Andrey

    2015-04-01

    The Zhelannoe high purity quartz deposit is located on the western slope of the Polar Urals. It is one of the largest deposits of vein quartz and rock crystal in Russia. Most of the mineralization is hosted within a single horizon of very firm quartz-sandstone, where plastic deformation did not occur almost entirely. All tectonic stress was released by the development of numerous thrust faults of different scales. Cavities formed during this process were later filled with quartz and rock crystal. In order to obtain more details on conditions under which mineralization took place, analysis of trace element contents in vein quartz and host rocks, and the micro-thermometric study of fluid inclusions in quartz have been carried out. The trace element composition of vein quartz and of the host rock has been determined by ICP-MS. The results have shown that concentrations of most of the 46 studied elements in quartz are two orders of magnitude lower than in chondrite, and more than three orders of magnitude lower than in the upper crust. Even though Pb and Li have the highest concentrations in quartz samples, levels are only nearly comparable in chondrite, and substantially lower in the upper crust. At the same time, negative anomalies of Pb and Li concentrations in the host rock may indicate the removal of these elements during vein quartz formation. Contents of most REEs are two orders of magnitude lower than in chondrite, and three orders of magnitude lower than in the host rock. Generally, the patterns of REE distribution in vein quartz and the host rock express a clear correlation; confirming the genetic link between vein quartz and quartz-sandstone host rock. However, the process of quartz recrystallization led to an intense decrease of REEs content, and of all other impurities, which consequently influenced industrial value of the Zhelannoe deposit. As a result of the micro-thermometric study of fluid inclusions in quartz, the following physical

  16. Zr and REE mineralization in sodic lujavrite from the Saima alkaline complex, northeastern China: A mineralogical study and comparison with potassic rocks

    Science.gov (United States)

    Wu, Bin; Wang, Ru-Cheng; Yang, Jin-Hui; Wu, Fu-Yuan; Zhang, Wen-Lan; Gu, Xiang-Ping; Zhang, Ai-Cheng

    2016-10-01

    The Triassic Saima alkaline complex on the Liaodong Peninsula, northeastern China, consists mainly of potassic phonolite, nepheline syenite, and sodic lujavrite. The lujavrite shows significant Zr-REE mineralization, which is present in the form of early magmatic, Zr-REE-enriched clinopyroxene (30%-40%), titanite (5%), and loparite-(Ce), and late magmatic to hydrothermal wadeite, widespread eudialyte group minerals (5%-10%), and catapleiite. Ultimately, the fractionation of the alkaline magma leads to the crystallization of mosandrite and hezuolinite. Textural relations and compositional variation among the characteristic Zr-REE-bearing minerals record that both Zr and REEs were strongly incompatible in the sodic melt, but that Zr mineralization preceded REE mineralization. The main Zr-REE mineralization in the Saima lujavrite resulted from the high peralkalinity, Na/K ratio and HFSE content, low oxygen fugacity, and the intensive activity of water and volatiles of its evolving magma. The discontinuous and abrupt changes in melt composition and mineral assemblage from the potassic nepheline syenite of the complex to the sodic lujavrite suggest that their magma was derived from different episodes of magmatic activity with different physico-chemical characteristics, rather than from the continuous evolution of a single magmatic event.

  17. The amphiboles of the REE-rich A-type peralkaline Strange Lake pluton - fingerprints of magma evolution

    Science.gov (United States)

    Siegel, Karin; Williams-Jones, Anthony E.; van Hinsberg, Vincent J.

    2017-09-01

    Major and trace element compositions of amphibole in igneous environments commonly reflect evolving magma compositions. In this study, we use the amphibole-group minerals from the Strange Lake, REE-enriched peralkaline granitic pluton to gain insights into the evolution of the magma. This 1240 Ma old pluton consists of two main intrusive facies, an early hypersolvus granite, which occurs as separate northern and southern intrusions, and a more evolved transsolvus granite. In the hypersolvus granite the amphibole is a late interstitial phase, whereas in the transsolvus granite, it is present as phenocrysts. The amphibole compositions vary from calcic-sodic (ferro-ferri-katophorite) in the southern hypersolvus granite to sodic (arfvedsonite, ferro-ferri-leakeite) in the other, more evolved granitic units. High Na, Si, Li, and low Al and Ca concentrations in the amphibole phenocrysts of the transsolvus granite indicate formation from a more evolved magma compared to the hypersolvus granite, despite the fact that these crystals formed early. We interpret the increasing Fe3+/Fe2+ ratios in the amphibole of the hypersolvus granite to reflect crystal chemical effects (Na/Ca-ratio) and increasingly oxidizing conditions in the magma, whereas in the phenocrysts of the transsolvus granite, the increasing ratio was the product of increasing proportions of F- and OH- in the melt. The amphiboles of all the granite units have elevated Nb, Zr, Hf and REE concentrations compared to the bulk rock, suggesting that these elements are compatible in amphibole. By contrast the much lower Ti concentration was due to saturation of the magma in sodium-titanosilicates. The amphibole REE concentrations vary greatly among the granite units. Amphibole of the southern and northern hypersolvus granite contains 0.16 and 0.07 wt.% ∑ REE + Y, on average, respectively, and in the transsolvus granite, the average ∑ REE content is only 0.01 wt.%, despite the more evolved nature of its host

  18. REE geochemistry of 3.2 Ga BIF from the Mapepe Formation, Barberton Greenstone Belt, South Africa

    Science.gov (United States)

    Yahagi, T. R.; Yamaguchi, K. E.; Haraguchi, S.; Sano, R.; Teraji, S.; Kiyokawa, S.; Ikehara, M.; Ito, T.

    2012-12-01

    Banded iron formations (BIFs) are chemical sediments interbedded with Fe- and Si-rich layers, characteristically present in the early history of the Earth. A popular hypothesis for the formation of BIFs postulates that dissolved oxygen produced by photosynthesizers such as cyanobacteria oxidized dissolved ferrous Fe supplied by submarine hydrothermal activities. During precipitation of Fe-oxide minerals, phosphorus and rare earth elements (REEs) were most likely adsorbed on their surface. Therefore, chemical compositions of REEs that adsorbed onto Fe-oxide have useful information on the seawater chemistry at the time of deposition. Especially, information on the redox state of seawater and the extent of the contribution of hydrothermal activity during BIF deposition are expected to have been recorded. Occurrence of BIF has been traditionally tied to the chemical evolution of the atmosphere. Rise of atmospheric oxygen, or as known as GOE (Great Oxidation Event: e.g., Holland, 1994), has been widely believed to have occurred at around 2.4 Ga ago. Contrary, however, some studies have suggested that such oxygenation could have occurred much earlier (e.g., Hoashi et al., 2009). In this study, we used 3.2 Ga old BIF from the Mapepe Formation at the bottom of the Fig Tree Group of the Swaziland Supergroup in the northeastern part of the Barberton Greenstone Belt, South Africa. We aimed to constrain the marine environment, and by inference atmospheric environment, at the time of BIF deposition from REE geochemistry. Major elements and REE compositions of 37 samples were measured using XRF and ICP-MS, respectively. Samples with less than 1.0 wt% Al2O3 are considered to be "pure" BIFs with minimal amount of continental contamination, and are expected to have inherited marine REE signatures. Abundance of REE normalized by C1 chondrite for the analyzed samples commonly exhibits positive Eu anomaly and LREE

  19. REE geochemistry of lamprophyres in Baimazhai nickel deposit, Yunnan Province, China: implication for the mantle source region

    Institute of Scientific and Technical Information of China (English)

    GUAN Tao; HUANG Zhilong; XU Cheng; ZHANG Zhenliang; YAN Zaifei; SHEN Baojian

    2005-01-01

    Based on the REE geochemistry data from the Baimazhai nickel deposit, Yunnan Province, the authors modeled the composition of the mantle source region by way of petrological mixing calculation, and further discussed the genesis of this type of rocks. Both element geochemistry data and mixing calculation showed that lamprophyres in the Baimazhai nickel deposit were derived from a metasomatism-enrichment mantle and the fluids resulted from dehydration of a subducted slab which is comprised of ALK-, LREE- and incompatible element-rich sediments.

  20. Discovery of Sr-bearing and LREE daughter minerals in fluid inclusions of Maoniuping REE deposit, Sichuan Province

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Maoniuping rare earth element (REE) deposit, located in Mianning area of Sichuan Province, is of unique geological characteristics and is large in scale. Some studies have shown that there are large amounts of multi phase fluid inclusions in fluorite, quartz and calcite. Besides the daughter minerals of halite, barite and gypsum, Sr bearing minerals (celestite, strontianite), apatite and eight light rare earth element (LREE) minerals have been found by scanning electron microscope/energy dispersive spectrometer techniques. The abundant occurrence of these daughter minerals shows that the ore-forming fluid is rich in Sr, Ba and LREE contents, and is related to nordmarkite in genesis.

  1. Applying a new understanding of supergene REE deposit formation to global exploration initiatives for environmentally sustainable resources

    Science.gov (United States)

    Hardy, Liam; Smith, Martin; Hood, Leo; Heller, Shaun; Faltyn, Rowan; Blum, Astrid; Bamberger, Axel

    2017-04-01

    Two new models have recently been proposed for the formation of REE ion-adsorption deposits and it is likely that they are both active in their related study profiles described in the Ambohimirahavavy Complex in Madagascar (Marquis et al, 2016) and the Serra de Monchique (SDM) complex in Portugal (Hardy et al, 2016). These are two separate environments presenting two different soil systems in terms of flora, protolith and structure. In the latosol profiles of SDM the natural sweating cycle of eucalyptus trees is proposed as the main geochemical cycling control for some 40% of Fe and 30% of Y, which have been observed migrating up and down profile seasonally between upper horizons and the rooting depths of these intensively farmed trees. If, through their natural cycle, eucalyptus trees in SDM are capable of concentrating depleted protolithic Y contents of 4-10ppm to some 140-160ppm in their enriched 150-200cm deep E horizons in only the 40 years since they were introduced to the region (Jenkins, 1979), then what potential deposits and concentrations may lay underneath older plantations across Brazil, Chile, China and most importantly, Australia, where these trees naturally cover some 16% of the entire continent. Eucalyptus is mostly farmed as pulp for paper mills and has lost its market value with the demand for paper decreasing, as the demand for REEs increases, ironically driven by the demand for the accessible technology to replace paper (EPA, 2012). Not only might there be great resources below these forests, but the removal of the aggressive intrusive species would be welcomed across Southern Europe and South America where they have limited market value and have destroyed local ecosystems and water supplies (Brito, 1999), where local people are actively seeking an alternative use of their lands. References: Brito, J. G. (1999). Management strategies for conservation of the lizard Lacerta schreiberi in Portugal. Biological conservation, 311-319. EPA. (2012

  2. REE Geochemistry of Sulfides from the Huize Zn-Pb Ore Field, Yunnan Province: Implication for the Sources of Ore-forming Metals

    Institute of Scientific and Technical Information of China (English)

    LI Wenbo; HUANG Zhilong; QI Liang

    2007-01-01

    REE abundances in sulfides from the Huize Zn-Pb ore field were determined with the ICPMS after preconcentration. The REE abundances in 26 sulfide samples (including pyrite, galena and sphalerite) are very low, with the ΣREE ranging from 1.6×10-9 to 166.8×10-9. Their LREE/HREE ratios range from 7.6 to 98, showing LREE enrichment relatively. The δEu values are below 1, indicating that they were deposited from an Eu-depleted and reducing fluid-system. Similar to the ore-hosting carbonate strata, calcite separates from carbonate veinlets filling in the fractures or faults crosscutting the carbonate strata also show clear Eu-depletion. This indicates that the carbonate veinlets and their parent fluid was possibly sourced from the strata and inherited the REE geochemical features of the strata. Therefore, REE-geochemical characteristics of both the sulfides and calcites, which were deposited from an ore-forming hydrothermal system, are similar to those of carbonate strata, and strongly suggest that the ore metals were mainly sourced from carbonate strata.

  3. Donnan membrane speciation of Al, Fe, trace metals and REEs in coastal lowland acid sulfate soil-impacted drainage waters.

    Science.gov (United States)

    Jones, Adele M; Xue, Youjia; Kinsela, Andrew S; Wilcken, Klaus M; Collins, Richard N

    2016-03-15

    Donnan dialysis has been applied to forty filtered drainage waters collected from five coastal lowland acid sulfate soil (CLASS) catchments across north-eastern NSW, Australia. Despite having average pH values70%) as negatively-charged complexes. In contrast, the speciation of the divalent trace metals Co, Mn, Ni and Zn was dominated by positively-charged complexes and was strongly correlated with the alkaline earth metals Ca and Mg. Thermodynamic equilibrium speciation calculations indicated that natural organic matter (NOM) complexes dominated Fe(III) speciation in agreement with that obtained by Donnan dialysis. In the case of Fe(II), however, the free cation was predicted to dominate under thermodynamic equilibrium, whilst our results indicated that Fe(II) was mainly present as neutral or negatively-charged complexes (most likely with sulfate). For all other divalent metals thermodynamic equilibrium speciation calculations agreed well with the Donnan dialysis results. The proportion of Al and REEs predicted to be negatively-charged was also grossly underestimated, relative to the experimental results, highlighting possible inaccuracies in the stability constants developed for these trivalent Me(SO4)2(-) and/or Me-NOM complexes and difficulties in modeling complex environmental samples. These results will help improve metal mobility and toxicity models developed for CLASS-affected environments, and also demonstrate that Australian CLASS environments can discharge REEs at concentrations an order of magnitude greater than previously reported.

  4. Concentrations and Distribution Patterns of Rare Earth Elements in Water Body from Intertidal Flat of Tianjin and Influence of Various Factors

    Institute of Scientific and Technical Information of China (English)

    王立军; 梁涛; 张朝生; 丁士明; 丁立强; 阎欣

    2004-01-01

    Concentrations and distribution patterns of rare earth elements(REEs)in the intertidal flat of Tianjin were studied using P507 resin and ICP-MS analytical technology. The results show that average concentrations of REEs in the filtered(dissolved REEs), unfiltered and interstitial water are 0.461 μg·L-1, 4.98 μg·L-1 and 0.845 μg·L-1, respectively. Their distribution patterns are similar to those in inland natural rivers, but quite different from those in oceans. The average concentrations of REEs in sediments and suspended matters are 161.2 mg·L-1 and 168.1 mg·L-1, respectively, which are much lower than those in sediments of natural rivers but higher than those in sediments of the continental shelf of East China Sea. It is suggested that REEs in sediments and suspended matters of intertidal flat can have mainly originated from terrestrial soils and thus their transportation and transformation processes are similar with those in rivers, and different from those in continental shelves. Pollutants discharged into the Bohai Bay do·not cause significant effect on REEs in the intertidal flat of Tianjin yet.

  5. Behaviour of major, minor and trace elements (including REEs during kaolinization processes at Zonouz deposit, northeast of Marand, East Azarbaidjan province

    Directory of Open Access Journals (Sweden)

    Vahideh Alipour

    2011-11-01

    Full Text Available The Zonouz kaolin deposit is located ~15 km northeast of Marand, East-Azarbaidjan province. Based on physical features in field investigations, such as color, five distinct kaolin types including (1 white, (2 lemon, (3 gray, (4 brown, and (5 yellow are distinguished in the deposit. Field evidence and petrographic studies indicate that the deposit is genetically close to trachy-andesite rocks. According to mineralogical data, the deposit contains quartz, kaolinite, montmorillonite, calcite, pyrophyllite, chlorite, muscovite-illite, dolomite, hematite, and anatase minerals. Geochemical data indicate that function of alteration processes on trachy-andesite rocks during development of Zonouz ore deposit was accompanied by leaching of elements such as Al, Na, K, Rb, Ba, V, Hf, Cu, Zr, Tm, Yb, and Lu, enrichment of elements such as U, Nb, and Ta, and leaching-fixation of elements such as Si, Fe, Ca, Mg, Ti, Mn, P, Cs, Sr, Th, Co, Cr, Ni, Y, Ga, LREE, Tb, Dy, Ho, and Er. Incorporation of obtained results from mineralogical and geochemical studies show that physico-chemical conditions of alteration environment, the relative stability of primary minerals, surface adsorption, preferential sorption by metallic oxides, existing of organic matters, scavenging and concentration processes, and fixation in neomorphic mineralogical phases played important role in distribution of elements in the deposit. Geochemical studies show that development of the deposit is relative to two types of processes, (1 hypogene and (2 supergene. The distribution pattern of REEs indicates that differentiation degree of LREEs from HREEs in supergene kaolins is more than hypogene kaolins. Geochemical studies indicate that minerals such as Mn-oxides, zircon, anatase, hematite, cerianite, and secondary phosphates (monazite, rhabdophane, churchite, and zenotime are the potential hosts for rare earth elements in this deposit.

  6. Discovery of Cu-Zn, Cu-Sn intermetallic minerals and its significance for genesis of the Mianning-Dechang REE Metallogenic Belt, Sichuan Province, China

    Institute of Scientific and Technical Information of China (English)

    XIE Yuling; HOU Zengqian; XU Jiuhua; YUAN Zhongxin; BAI Ge; LI Xiaoyu

    2006-01-01

    Mianning-Dechang Himalayan REE Metallogenetic Belt in Sichuan Province lies along the western margin of the Yangtze Craton. We have conducted detailed mineralogical studies on ore minerals collected from Maoniuping and Dalucao, the two largest deposits in the belt. With optical microscope, SEM/EDS, and EPMA, three rare intermetallic minerals, i.e., zinccopperite (Cu2Zn), Sn- bearing native copper, and Cu-bearing jupiter were found to occur in the main ore along with barite, fluorite, apatite, sulfide and bastnaesite. Since the conditions under which zinccopperite and Sn- bearing native copper formed are quite unique, finding of these minerals, for the first time in domestic REE deposits, has significant implications for the genesis of the ore deposits in which they occur. In comparison with Cu-Zn intermetallic minerals in other occurrences, we propose that the formation of this REE metallogenetic belt is associated with fast upwelling of the Himalayan magma from deep source.

  7. Trace elements and REE fractionation in subsoils developed on sedimentary and volcanic rocks: case study of the Mt. Vulture area, southern Italy

    Science.gov (United States)

    Mongelli, Giovanni; Paternoster, Michele; Rizzo, Giovanna; Sinisi, Rosa

    2014-06-01

    There is an increasing interest in the distribution of rare earth elements (REEs) within soils, primarily as these elements can be used to identify pedogenetic processes and because soils may be future sources for REE extraction, despite much attention should be paid to the protection and preservation of present soils. Here, we evaluate the processes that control the distribution of REEs in subsoil horizons developed over differing lithologies in an area of low anthropogenic contamination, allowing estimates of the importance of source rocks and weathering. Specifically, this study presents new data on the distribution of REEs and other trace elements, including transition and high-field-strength elements, in subsoils developed on both Quaternary silica-undersaturated volcanic rocks and Pliocene siliciclastic sedimentary rocks within the Mt. Vulture area of the southern Apennines in Italy. The subsoils in the Mt. Vulture area formed during moderate weathering (as classified using the chemical index of alteration) and contain an assemblage of secondary minerals that is dominated by trioctahedral illite with minor vermiculite. The REEs, high-field-strength elements, and transition metals have higher abundances in subsoils that developed from volcanic rocks, and pedogenesis caused the Mt. Vulture subsoils to have REE concentrations that are an order of magnitude higher than typical values for the upper continental crust. This result indicates that the distribution of REEs in soils is a valuable tool for mineral exploration. A statistical analysis of inter-elemental relationships indicates that REEs are concentrated in clay-rich fractions that also contain significant amounts of low-solubility elements such as Zr and Th, regardless of the parent rock. This suggests that low-solubility refractory minerals, such as zircon, play a significant role in controlling the distribution of REEs in soils. The values of (La/Yb)N and (Gd/Yb)N fractionation indices are dependent on

  8. Aplicació de models font-receptor per a determinar àrees font de components biològics (pol·len i papallones)

    OpenAIRE

    Alarcón Jordán, Marta

    2010-01-01

    Els models font-receptor permeten establir relacions entre un punt receptor (punt de mostreig) i les àrees font probables (regions emissores) mitjançant l’associació de valors de concentració en el punt receptor amb les corresponents retrotrajectòries atmosfèriques, i, juntament amb altres tècniques, permeten interpretar fenòmens de transport a escala sinòptica. No obstant això, fins a l'actualitat, pocs treballs han aplicat aquests tipus de models per descriure les àrees font d'organismes bi...

  9. The behaviour of REE and Zr-Hf fractionation in the volcanic waters of Nevado del Ruiz system (Colombia)

    Science.gov (United States)

    Inguaggiato, Claudio; Censi, Paolo; Zuddas, Pierpaolo; Makario Londoño, John; Chacón, Zoraida; Alzate, Diego; Brusca, Lorenzo; D'Alessandro, Walter

    2015-04-01

    The geochemical behaviour of Rare Earth Element (REE), Zr and Hf have been investigated in the thermal waters of Nevado del Ruiz volcanic system. These fluids are characterised by a wide range of pH ranging between 1.0 and 8.8. The acidic waters are sulphate dominated with different Cl/SO4 ratios. The Nevado del Ruiz waters allowed to investigate the behaviour of investigated elements in a wide spectrum of pH and chemical composition of water. The important role of the pH and the ionic complexes have been evidenced in the distribution of REE, Zr and Hf in the aqueous phase. The pH rules the precipitation of authigenic oxyhydroxides of Fe, Al producing changes in REE, Zr, Hf amount and strong anomalies of Cerium and Europium. Y-Ho and Zr-Hf (twin pairs) have different behaviour in strong acidic waters with respect to the water with higher pH. Yttrium and Ho have the same behaviour of Zr and Hf in waters with pH near neutral-to-neutral, showing super-chondritic ratios. The twin pairs showed to be sensitive to the co-precipitation and/or adsorption onto the surface of authigenic particulate suggesting an enhanced scavenging of Ho and Hf respect to Y and Zr, leading to super-chondritic ratios. In acidic waters a different behaviour of twin pairs occurs with chondritic Y/Ho ratios (reflecting the Y/Ho ratio of average local rock) and sub-chondritic Zr/Hf ratios. For the first time, Zr and Hf have been investigated in natural acidic fluids to understand the behaviour of these elements in extreme acidic conditions and different major anions chemistry. Zr/Hf molar ratio changes from 4.75 to 49.29 in water with pH<3.6. In strong acidic waters, a different fractionation of Zr and Hf have been recognised as function of major anion contents (Cl and SO4), suggesting the formation of complexes leading to sub-chondritic Zr/Hf molar ratios.

  10. Landslide-induced iron mobilisation shapes benthic accumulation of nutrients, trace metals and REE fractionation in an oligotrophic alpine stream

    Science.gov (United States)

    Johnston, Scott G.; Rose, Andrew L.; Burton, Edward D.; Webster-Brown, Jenny

    2015-01-01

    Large alpine landslides that entrain substantial organic material below the water table and create suspended floodplains may have long-term consequences for the mobilisation of redox sensitive elements, such as Fe, into streamwaters. In turn, the cycling of iron in aquatic systems can influence the fate of nutrients, alter primary productivity, enhance accumulation of trace metals and induce fractionation of rare earth elements (REE). In this study we examine a reach of a pristine oligotrophic alpine stream bracketing a 30 year-old landslide and explore the consequences of landslide-induced Fe mobilisation for aqueous geochemistry and the composition of benthic stream cobble biofilm. Elevated Fe2+ and Mn in landslide zone stream waters reflect inputs of circumneutral groundwater from the landslide debris-zone floodplain. Geochemical characteristics are consistent with reductive dissolution being a primary mechanism of Fe2+ and Mn mobilisation. Stream cobble biofilm in the landslide zone is significantly (P extractable; Fe(III)Ab). While the landslide zone accounts for less than ∼9% of the total stream length, we estimate it is responsible for approximately 60-80% of the stream's benthic biofilm load of poorly crystalline Fe(III) and Mn. Biofilm Fe(III) precipitates are comprised mainly of ferrihydrite, lepidocrocite and an organic-Fe species, while precipitate samples collected proximal to hyporheic seeps contain abundant sheath structures characteristic of the neutrophilic Fe(II)-oxidising bacteria Leptothrix spp. Stream-cobble Fe(III)-rich biofilm is accumulating PO43- (∼3-30 times background) and behaving as a preferential substrate for photosynthetic periphyton, with benthic PO43-, chlorophyll a, organic carbonHCl and total N all significantly positively correlated with Fe(III)Ab and significantly elevated within the landslide zone (P transformed basis. Stream cobble biofilm also exhibits distinct REE fractionation along the flow path, with light REE (La

  11. Donnan membrane speciation of Al, Fe, trace metals and REEs in coastal lowland acid sulfate soil-impacted drainage waters

    Energy Technology Data Exchange (ETDEWEB)

    Jones, Adele M.; Xue, Youjia [School of Civil and Environmental Engineering, University of New South Wales, Sydney, NSW 2052 (Australia); Kinsela, Andrew S. [School of Civil and Environmental Engineering, University of New South Wales, Sydney, NSW 2052 (Australia); Institute for Environmental Research (IER), Australian Nuclear Science and Technology Organisation (ANSTO), Lucas Heights, NSW 2234 (Australia); Wilcken, Klaus M. [Institute for Environmental Research (IER), Australian Nuclear Science and Technology Organisation (ANSTO), Lucas Heights, NSW 2234 (Australia); Collins, Richard N., E-mail: richard.collins@unsw.edu.au [School of Civil and Environmental Engineering, University of New South Wales, Sydney, NSW 2052 (Australia)

    2016-03-15

    Donnan dialysis has been applied to forty filtered drainage waters collected from five coastal lowland acid sulfate soil (CLASS) catchments across north-eastern NSW, Australia. Despite having average pH values < 3.9, 78 and 58% of Al and total Fe, respectively, were present as neutral or negatively-charged species. Complementary isotope dilution experiments with {sup 55}Fe and {sup 26}Al demonstrated that only soluble (i.e. no colloidal) species were present. Trivalent rare earth elements (REEs) were also mainly present (> 70%) as negatively-charged complexes. In contrast, the speciation of the divalent trace metals Co, Mn, Ni and Zn was dominated by positively-charged complexes and was strongly correlated with the alkaline earth metals Ca and Mg. Thermodynamic equilibrium speciation calculations indicated that natural organic matter (NOM) complexes dominated Fe(III) speciation in agreement with that obtained by Donnan dialysis. In the case of Fe(II), however, the free cation was predicted to dominate under thermodynamic equilibrium, whilst our results indicated that Fe(II) was mainly present as neutral or negatively-charged complexes (most likely with sulfate). For all other divalent metals thermodynamic equilibrium speciation calculations agreed well with the Donnan dialysis results. The proportion of Al and REEs predicted to be negatively-charged was also grossly underestimated, relative to the experimental results, highlighting possible inaccuracies in the stability constants developed for these trivalent Me(SO{sub 4}){sub 2}{sup −} and/or Me–NOM complexes and difficulties in modeling complex environmental samples. These results will help improve metal mobility and toxicity models developed for CLASS-affected environments, and also demonstrate that Australian CLASS environments can discharge REEs at concentrations an order of magnitude greater than previously reported. - Highlights: • CLASS discharge large amounts of metals and their speciation is poorly

  12. 塔里木盆地古城低凸起中下奥陶统白云岩稀土元素地球化学特征及其成因%REE Geochemical Characteristics and Genesis of the Middle-Lower Ordovician Dolomite in the Gucheng Low Uplift of the Tarim Basin

    Institute of Scientific and Technical Information of China (English)

    张振伟

    2016-01-01

    The Middle-Lower Ordovician dolomite in the Gucheng Low Uplift of the Tarim Basin is the main reservoir of natural gas in the area.Based on characteristics of texture and structures,six kinds of dolomite have been classified in this paper.They include fine to micritic dolomite,fine to crystalline anhedral dirty dolomite,fine to medium sized euhedral dolomite,medium to coarse grained dirty dolomite,medium to coarse grained clean dolomite,and saddle dolomite.Their REE contents have been measured.Results show that the total contents of REE are relatively low,with positive correlations between the REE and LaN/YbN or LREE/HREE ratios,but poor correlations between the REE and δEu orδCe values. The REE distribution patterns of various types of dolomite are generally flat,slightly right declined,and LREE slightly en-riched,with very limited differences among them.The genetic types of various kinds of dolomite are slightly different.They include penecontemporaneous evaporative pumping dolomitization,penecontemporaneous seepage reflux dolomitization, shallow burial dolomitization,and hydrothermal dolomitization.%中下奥陶统白云岩是塔里木盆地古城低凸起主要的天然气储集层,按结构特征将其分为粉-微晶白云石、粉-细晶级他形脏白云石、粉-中晶级自形白云石、中-粗晶脏白云石、中-粗晶干净白云石和鞍形白云石等6种类型,对不同类型白云岩的稀土元素分析结果表明,研究区样品的REE总体含量偏低,与LaN/YbN、LREE/HREE大致呈正相关,与 δEu、δCe的相关性较差.不同类型白云石稀土元素配分曲线差别不大,均为总体平缓、略向右倾,显示轻稀土略微富集.不同类型白云石成因类型略有不同,主要为同生期蒸发泵成因、同生期渗透回流成因、浅埋藏成因和热液成因等4种成因类型.

  13. SHRIMP U–Pb and REE data pertaining to the origins of xenotime in Belt Supergroup rocks: evidence for ages of deposition, hydrothermal alteration, and metamorphism

    Science.gov (United States)

    Aleinikoff, John N.; Lund, Karen; Fanning, C. Mark

    2015-01-01

    derivation. A previous study on the Revett Formation at the Spar Lake Ag–Cu deposit provides data for xenotime overgrowths in several ore zones formed by hydrothermal processes; herein, those results are compared with data from newly analyzed diagenetic, metamorphic, and magmatic xenotime overgrowths. The origin of a xenotime overgrowth is reflected in its rareearth element (REE) pattern. Detrital (i.e., igneous) xenotime has a large negative Eu anomaly and is heavy rare-earth element (HREE)-enriched (similar to REE in igneous zircon). Diagenetic xenotime has a small negative Eu anomaly and flat HREE (Tb to Lu). Hydrothermal xenotime is depleted in light rare-earth element (LREE), has a small negative Eu anomaly, and decreasing HREE. Metamorphic xenotime is very LREE-depleted, has a very small negative Eu anomaly, and is strongly depleted in HREE (from Gd to Lu). Because these characteristics seem to be process related, they may be useful for interpretation of xenotime of unknown origin. The occurrence of 1.16–1.05 Ga metamorphic xenotime, in the apparent absence of pervasive deformation structures, suggests that the heating may be related to poorly understood regional heating due to broad regional underplating of mafic magma. These results may be additional evidence (together with published ages from metamorphic titanite, zircon, monazite, and garnet) for an enigmatic, Grenville-age metamorphic event that is more widely recognized in the southwestern and eastern United States

  14. Thulium anomalies and rare earth element patterns in meteorites and Earth: Nebular fractionation and the nugget effect

    CERN Document Server

    Dauphas, N

    2015-01-01

    This study reports the bulk rare earth element (REEs, La-Lu) compositions of 41 chondrites, including 32 falls and 9 finds from carbonaceous (CI, CM, CO and CV), enstatite (EH and EL) and ordinary (H, L and LL) groups, as well as 2 enstatite achondrites (aubrite). The CI-chondrite-normalized REE patterns and Eu anomalies in ordinary and enstatite chondrites show more scatter in more metamorphosed than in unequilibrated chondrites. This is due to parent-body redistribution of the REEs in various carrier phases during metamorphism. The dispersion in REE patterns of equilibrated ordinary chondrites is explained by the nugget effect associated with concentration of REEs in minor phosphate grains. Terrestrial rocks and samples from ordinary and enstatite chondrites display negative Tm anomalies of ~-4.5 % relative to ca chondrites. In contrast, CM, CO and CV (except Allende) show no significant Tm anomalies. Allende CV chondrite shows large excess Tm (~+10 %). These anomalies are similar to those found in group II...

  15. Mineralogy and geochemistry of REE-Zr-Nb mineralised nepheline syenites in the peralkaline Ilímaussaq complex, South Greenland

    DEFF Research Database (Denmark)

    Borst, Anouk Margaretha

    for these elements. This thesis focusses on the Mesoproterozoic Ilímaussaq complex (c. 1160 ± 5 Ma) in Southern Greenland, a well-known alkaline intrusion that hosts significant resources of REE, as well as zirconium, niobium, tantalum, uranium, lithium and zinc. The Ilímaussaq complex is part of the rift...

  16. REE in suspended particulate matter and sediment of the Zuari estuary and adjacent shelf, western India: Influence of mining and estuarine turbidity

    Digital Repository Service at National Institute of Oceanography (India)

    Shynu, R.; Rao, V.P.; Parthiban, G.; Balakrishnan, S.; Narvekar, T.; Kessarkar, P.M.

    and estuarine processes. Concentrations of SPM were low in the upper estuary, increased seaward with high values in the lower estuary and then decreased at stations in the bay in all seasons. The distributions of mean Sigma REE, Al and Fe along transect imitate...

  17. REE and Other Trace Element Chemistry of Oldhamite(CaS) in the Qingzhen Chondrite(EH3) and Their Genetic Implications

    Institute of Scientific and Technical Information of China (English)

    陈永享; ERNSTPERNICKA; 等

    1993-01-01

    Instrumental neutron activation analysis(INAA) of 14 single oldhamite grains separated from the Qingzhen chondrite (EH3) for refractory(La,Ce,Sm ,Eu,Yb,Lu,Ca,Sc,Hf, and Th),volatile (Na,Cr,Zn,Se,Br,etc.)and siderophile elements (Fe,Ni,Co,Ir,Au ,and As) revealed that oldhamite is highly rich in refractory elements.The mineral serves as the principal carrier of REE and contains about 80% of the REEs in the Qingzhen enstatite chondrite .Furthermore, the large enrichment of LREE relative to HREE is noticed in oldhamite from the Qingzhen .In general, the oldhamite from metal-sulfide assemblages is richer in REE than that from the matrix,i.e.,the earlier the oldhamite grains condensed, the richer they are in REE. Meanwhile.oldhamite is also rich in vol-atile elements such as Se,Br, etc.In terms of the distribution of trace elements in oldhamitc from the Qingzhen ,the chondrite is srggested to have resulted from high-temperature condensation of solar nebula.

  18. Late Archaean mantle metasomatism below eastern Indian craton: Evidence from trace elements, REE geochemistry and Sr-Nd-O isotope systematics of ultramafic dykes

    Indian Academy of Sciences (India)

    Abhijit Roy; A Sarkar; S Jeyakumar; S K Aggrawal; M Ebihara; H Satoh

    2004-12-01

    Trace, rare earth elements (REE), Rb-Sr, Sm-Nd and O isotope studies have been carried out on ultramafic (harzburgite and lherzolite) dykes belonging to the newer dolerite dyke swarms of eastern Indian craton. The dyke swarms were earlier considered to be the youngest mafic magmatic activity in this region having ages not older than middle to late Proterozoic. The study indicates that the ultramafic members of these swarms are in fact of late Archaean age (Rb-Sr isochron age 2613 ± 177 Ma, Sri ∼0.702 ± 0.004) which attests that out of all the cratonic blocks of India, eastern Indian craton experienced earliest stabilization event. Primitive mantle normalized trace element plots of these dykes display enrichment in large ion lithophile elements (LILE), pronounced Ba, Nb and Sr depletions but very high concentrations of Cr and Ni. Chondrite normalised REE plots exhibit light REE (LREE) enrichment with nearly flat heavy REE (HREE; ( HREE)N ∼ 2-3 times chondrite, (Gd/Yb)N∼1). The Nd(t) values vary from +1.23 to −3.27 whereas 18O values vary from +3.16‰ to +5.29‰ (average +3.97‰ ± 0.75‰) which is lighter than the average mantle value. Isotopic, trace and REE data together indicate that during 2.6 Ga the nearly primitive mantle below the eastern Indian Craton was metasomatised by the fluid (±silicate melt) coming out from the subducting early crust resulting in LILE and LREE enriched, Nb depleted, variable Nd, low Sri(0.702) and low 18O bearing EMI type mantle. Magmatic blobs of this metasomatised mantle were subsequently emplaced in deeper levels of the granitic crust which possibly originated due to the same thermal pulse.

  19. Golan Heights Groundwater Systems: Separation By REE+Y And Stable Isotopes

    Science.gov (United States)

    Siebert, C.; Geyer, S.; Knoeller, K.; Roediger, T.; Weise, S.; Dulski, P.; Moeller, P.; Guttman, J.

    2008-12-01

    In a semi-arid to arid country like Israel, all freshwater resources are under (over-) utilization. Particularly, the Golan Heights rank as one of the most important extraction areas of groundwater of good quality and quantity. Additionally the mountain range feed to a high degree the most important freshwater reservoir of Israel, the Sea of Galilee. Hence, knowing the sources and characters of the Golan Heights groundwater systems is an instantaneous demand regarding sustainable management and protection. Within the "German-Israeli-Jordanian-Palestinian Joint Research Program for the Sustainable Utilisation of Aquifer Systems", hundreds of water samples were taken from all over the Jordan-Dead Sea rift-system to understand groundwater flow-systems and salinisation. For that purpose, each sample was analysed for major and minor ions, rare earth elements including yttrium (REY) and stable isotopes of water (d18O, d2H). The REY distribution in groundwater is established during infiltration by the first water-rock interaction and consequently reflects the leachable components of sediments and rocks of the recharge area. In well- developed flow-systems, REY are adsorbed onto pore surfaces are in equilibrium with the percolating groundwater, even if the lithology changes (e.g. inter-aquifer flow). Thus, groundwater sampled from wells and springs still show the REY distribution pattern established in the recharge area. Since high temperatures do not occur in Golan Heights, d2H and d18O are less controlled by water-rock interaction than by climatic and geomorphological factors at the time of replenishment. Applying the REY signature as a grouping criterion of groundwaters, d18O vs. d2H plots yield a new dimension in interpreting isotope data. The combined use of hydrochemical and isotopic methods enabled us to contain the areas of replenishment and the flow-paths of all investigated groundwater in the Golan Heights. Despite location, salinity or temperature of spring or

  20. Origin of heavy REE mineralisation in carbonatites: Constraints form the Huanglongpu Mo-HREE deposit, Qinling, China.

    Science.gov (United States)

    Smith, Martin; Cheng, Xu; Kynicky, Jindrich; Cangelosi, Delia; Wenlei, Song

    2017-04-01

    The carbonatite dykes of the Huanglongpu area, Lesser Qinling, China, are unusual in that they are quartz-bearing, Mo-mineralised and enriched in the heavy rare earth elements (HREE) relative to typical carbonatites. Carbonatite monazite (208.9±4.6 Ma to 213.6±4.0; Song et al., 2016) gives a comparable U-Pb radiometric age to molybdenite (220Ma; Stein et al., 1997), confirming interpretations that Mo is derived from the carbonatite, and not a subsequent overprint from regional porphyry-style mineralisation ( 141Ma). The sulphides in the carbonatites have mantle-like 34S ( 1‰) and low δ26Mg values (-1.89 to -1.07‰), similar to sedimentary carbonates, suggesting a recycled sediment contribution in their mantle sources that may be responsible for the Mo and HREE enrichment (Song et al., 2016). The textures of REE minerals indicate crystallisation of monazite-(Ce), bastnäsite-(Ce), parisite-(Ce) and aeschynite-(Ce) as magmatic phases. Monazite-(Ce) was subsequently altered to produce apatite, which was in turn replaced by britholite-(Ce), accompanied by the formation of allanite-(Ce). The REE-fluorcarbonates where replaced by synchysite-(Ce) and röntgenite-(Ce). Aeschynite-(Ce) was altered initially to uranopyrochlore and then pyrochlore with uraninite inclusions. The mineralogical evolution reflects the evolution from magmatic carbonatite, through to more silica-rich conditions during the magmatic-hydrothermal transition, to fully hydrothermal conditions accompanied by the formation of sulphate minerals. Each alteration stage resulted in the preferential leaching of the LREE and enrichment in the HREE. Mass balance considerations indicate that the HREE enrichment could not be a passive process, and that hydrothermal fluids must have contributed HREE to the system. The evolution of the fluorcarbonate mineral assemblage requires an increase in aCa2+ and aCO32- in the metasomatic fluid, and so breakdown of HREE-enriched calcite may have been the HREE source

  1. 皖北九顶山组灰岩稀土元素地球化学特征及对古海水的制约%Geochemical characteristics of REE in limestone of Jiudingshan Formation,northern Anhui Province and their constraint on the seawater

    Institute of Scientific and Technical Information of China (English)

    陈松; 桂和荣; 孙林华; 刘向红; 马艳平

    2011-01-01

    In this paper, petrological and rare earth element analysis was carried out for limestone collected from the Jiudingshan Formation in northern Anhui Province, the origin of REE in limestone was studied, and the rare earth elements distribution patterns of the seawater were inversed. The results imply that rare earth elements in the limestone were mainly controlled by ancient oceans, without the influence of detrital material, that the total rare earth elements (REE) content is rather low, only 8.54 * 10-6 on average, and the light and heavy REE are strictly fractionated, indicating normal neritic deposit. The REE distribution patterns of seawater is depleted in HREE, similar to things of limestone, and a very good positive correlation exists between Y/Ho and Y/Dy (R2=0.97) in limestone and seawater. The seawater has high Y/Ho ratios and negative Ce anomaly, with the δ EuNASC being lower than 1, suggesting that the ancient seawater was similar to modern seawater.%采集皖北新元古代九顶山组灰岩进行了系统的岩石学和稀土地球化学分析,研究了灰岩中稀土元素的来源,并对海水的稀土配分模式进行反演,结果表明:灰岩中稀土元素主要受控于古海洋,基本不受陆源物质影响;灰岩样品中稀土含量很低,平均为8.54×10-6,轻重稀土分异明显,为正常浅海沉积;海水稀土配分模式与灰岩相似,为重稀土亏损,灰岩和海水的Y/Ho、Y/Dv值呈正相关;海水具有较高的Y/Ho比、Ce负异常,且海水的δEuNASC值小于1,表明了新元古代海水与现代海水的稀土元素特征基本相似.

  2. 四川拉拉IOCG矿床方解石REE与C,O同位素地球化学特征及意义%REE and carbon-oxygen isotope geochemistry of calcite from Lala IOCG deposit, Sichuan and its significance

    Institute of Scientific and Technical Information of China (English)

    黄从俊; 李泽琴

    2016-01-01

    calcite, and the features and source of ore-forming fluids were discussed through systematic investigation of REE and C-O isotope geochemistry of calcites. The results show that the average åwREE ,δ(13CPDB) andδ(18OSMOW) of calcite (Ⅰ) are 75.98×10−6, −3.84‰−0‰ and 9.45‰−12.2‰, respectively, while the calcite (Ⅱ) are 313.85×10−6,−3.98‰~−1.40‰and 8.1‰~11.6‰, respectively. The results show that calcite (Ⅰ) is not the main carrier of REE in the MMS, and its ore-forming fluid has very low åwREE . Calcite (Ⅱ) is the dominate REE carrier of HMS, and its ore-forming fluid has higher åwREE than calcite (Ⅰ). Both calcite (Ⅰ) and calcite (Ⅱ) are hydrothermal origin,water-rock interaction and cooling effect the precipitation of calcite, but their ore-forming fluids have different sources. REE distribution pattern of calcite (Ⅰ) is flat type. There are both positive and negative Eu anomalies, and no Ce anomaly, which is controlled by the stability of REE complexes in the fluid. The ore-forming fluid of calcite(Ⅰ) is a kind of high temperature residual fluid after the precipitation of a large number of LREE, and has inherited characteristics of the surrounding marine eruption volcanic rock. REE distribution pattern of calcite (Ⅱ) is leftist type, with significant positive Eu anomaly and no Ce anomaly, which is controlled by crystal chemical factors. The ore-forming fluid of calcite (Ⅱ) is a kind of hot brine originated from the reaction between meteoric water and surrounding rocks, which has a feature of low temperature and high oxygen fugacity. C of calcite (Ⅰ) is derived from mantle fluids and marine carbonates, while C of calcite (Ⅱ) is sourced from CO2 which is released by gabbro magma. O isotope obviously has negative drift being affected by meteoric water.

  3. Isotopic evidence for trapped fissiogenic REE and nucleogenic Pu in apatite and Pb evolution at the Oklo natural reactor

    Science.gov (United States)

    Horie, Kenji; Hidaka, Hiroshi; Gauthier-Lafaye, François

    2004-01-01

    A part of the boundary layer of reactor zone 10 at the Oklo natural reactor shows a unique petrologic texture, which contains high-grade uraninite and massive apatite concretions. In order to study distribution behavior of fission products around the boundary between the reactor zone and the wall rock and to clarify the relation of migration mechanisms of fission products with geochemical factors, in-situ isotopic analyses of Nd, Sm, Gd, Pb and U in uraninite and apatite from the sample were performed by Sensitive High Resolution Ion Microprobe (SHRIMP). Sm and Gd isotopic ratios of uraninite and apatite show evidence of neutron irradiation with fluence between 4.4-6.8×10 19 n/cm 2. Judging from the isotopic anomalies of Nd and U, the apatite coexisting with the uraninite plays an important role in trapping fissiogenic LREE and nucleogenic 239Pu into the structure. Systematic Pb isotopic data from apatite, uraninite, galena and minium suggest the following chronological interpretations. The apatite formed 1.92±0.01 Ga ago and trapped fissiogenic light REE and nucleogenic 239Pu that migrated from the reactor during the criticality. The uraninite around the boundary between reactor and sandstone dissolved once 1.1˜1.2 Ga ago. Galena grains were formed by U-Pb mobilization in association with the intrusion of dolerite dyke 0.45˜0.83 Ga ago. Minium was derived from recent dissolution of galena under locally oxidizing conditions.

  4. Morphological and molecular characterisation of Ditrachybothridium macrocephalum Rees, 1959 (Cestoda: Diphyllidea) from Galeus melastomus Rafinesque in the Western Mediterranean.

    Science.gov (United States)

    Dallarés, Sara; Pérez-Del-Olmo, Ana; Carrassón, Maite; Kuchta, Roman

    2015-09-01

    New morphological, molecular and ecological data for Ditrachybothridium macrocephalum Rees, 1959 (Cestoda: Diphyllidea) are presented and discussed based on specimens recovered from the blackmouth catshark Galeus melastomus Rafinesque (Scyliorhinidae) in the Western Mediterranean. A redescription of the plerocercus of this parasite is provided and new data on immature and mature worms including the first description of the eggs are reported, based on light and scanning electron microscopy observations. Analysis of 28S rDNA (domains D1-D3) sequences from plerocerci, immature and adult specimens revealed that they are conspecific with specimens from the North East Atlantic. Although previous authors considered that museum specimens identified as D. macrocephalum may represent more than one species, examination of type- and voucher material revealed no relevant morphological differences between museum specimens and the present material. Information on infection levels of D. macrocephalum is provided from a large number of host specimens (n = 170). This species was more abundant in juvenile than in adult hosts and on the middle slope than on the upper slope; this may be related to ontogenetic and bathymetric diet shifts of G. melastomus.

  5. Determination of weathering rate of the Morro do Ferro Th-REEs deposit, Brazil using U-isotope method

    Energy Technology Data Exchange (ETDEWEB)

    Bonotto, D.M. [Departamento de Petrologia e Metalogenia, Universidade Estadual Paulista (UNESP), Campus de Rio Claro, Avnue 24-A No.1515, C.P. 178, CEP 13506-900, Rio Claro, Sao Paulo (Brazil)]. E-mail: dbonotto@rc.unesp.br; Fujimori, K. [In Memoriam, Departamento de Geofisica, Instituto de Astronomia, Geofisica e Ciencias Atmosfericas (IAG-USP), Rua do Matao No. 1226, CEP 05508-900, Sao Paulo (Brazil); Moreira-Nordemann, L.M. [Instituto de Pesquisas Espaciais (INPE-MCT-CNPq), Av. dos Astronautas No. 1758, CEP 12227-010, Sao Jose dos Campos, Sao Paulo (Brazil)

    2007-05-15

    The weathering rate was estimated by changes in {sup 234}U/{sup 238}U activity ratio (AR) and U content of rocks, borehole spoil and surface water samples at the Morro do Ferro Th-REEs deposit. The deposit is situated in the Pocos de Caldas alkaline massif, Brazil. The south stream basin investigated in this paper has not been significantly affected by anthropogenic inputs of pollutants as compared to the Corumbatai River basin in Sao Paulo State, where the method was previously applied. The weathering rate derived utilizing the U-isotopes modeling corresponded to 0.015 mm/yr (67,000 years to weather 1 m of rock under the actual climatic conditions). The estimated rate is very reasonable in comparison with the range of 0.015-0.05 mm/yr of land surface lowering within the entire caldera. It is also compatible with a rate of 0.013 mm/yr determined for the Salgado River basin in a semi-arid region in Bahia State, Brazil. The value generated is reliable and increases the potential use of the method for other different areas in Brazil and elsewhere, because it may be used in regions with different climatic conditions and (un)polluted basins.

  6. The Content of Placer Heavy Mineral and Characteristics of REE at Toboali Coast and Its Surrounding Area, Bangka Belitung Province

    Directory of Open Access Journals (Sweden)

    Noor CD Aryanto

    2017-02-01

    At Toboali coast, South Bangka the presence of REE in sediments are above the Earth's crust generally. They’re concentrations, such as La (5.07 to 199 ppm, Ce (106-394 ppm, Pr (5.11-59.7 ppm, Nd (16.5-201 ppm, Sm (9.97-52.3 ppm, Eu (0.18-1.55 ppm, Gd (9.11-39.3 ppm, Tb (1.35-8.14 ppm, Dy (9.01-56.3 ppm, Ho (1.89-12.3 ppm, Er (5.19-33.9 ppm, Tm (0.77-5.62 ppm, Yb (3.3-37.5 ppm and Lu (0.71-5.41 ppm. LREE (La-Eu highest content is generally found in the location of the tailings sludge (TBL-13C, not so in HREE (Gd-Lu, the highest content is widely available on the sandy beach sediments (TBL-13B. Tectonic environment of Toboali granitoid rocks by plotting a spider diagram refers to the chondrite normalization is continental magmatic arc.

  7. Seawater rare-earth element patterns preserved in apatite of Pennsylvanian conodonts?

    Science.gov (United States)

    Bright, Camomilia A.; Cruse, Anna M.; Lyons, Timothy W.; MacLeod, Kenneth G.; Glascock, Michael D.; Ethington, Raymond L.

    2009-03-01

    Past workers have used rare-earth element patterns recorded in biogenic apatite as proxies for original seawater chemistry. To explore the potency of this approach, we analyzed Pennsylvanian conodonts from limestones, gray shales, and black shales of the Fort Scott and Pawnee formations (Desmoinesian) and Swope and Dennis formations (Missourian) in Kansas, Missouri, and Iowa, U.S.A. Analysis of individual platform conodonts from seven taxa using laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) revealed a consistent enrichment in the middle rare-earth elements (MREE). Analogous MREE enrichment has been observed in authigenic apatite and bulk samples of phosphate-rich black shales from the same formations. Importantly, however, phosphate-depleted shales intimately associated with the P-rich intervals are relatively depleted in MREE. These antithetic patterns argue convincingly for secondary migration from the bulk sediment into the phosphate, and the extent of MREE enrichment in the conodonts is correlated positively with the total REE content. MREE enrichment in conodonts does not vary systematically as a function of lithology, stratigraphic level, conodont genus, geographic location, or with independent estimates of paleoredox conditions in the bottom waters. Collectively, these results argue for postmortem (diagenetic) REE uptake resulting in a pronounced (and progressive) MREE enrichment. Any cerium anomalies, if initially present, were masked by diagenetic uptake of REE. Paleoenvironmental interpretations of conodont REE, particularly for samples exhibiting MREE enrichment, should therefore be viewed with caution.

  8. REE: Alkaline intensive and carbonates complexes at Fuerteventura (Canary Islands). Mineralizaciones de tierras raras: los complejos de rocas plutonicas alcalinas y carbonatitas del complejo basal de Fuerteventura (Islas Canarias)

    Energy Technology Data Exchange (ETDEWEB)

    Mangas Viuela, J.; Perez Torrado, F.J.

    1993-01-01

    Alkaline intrusive complexes at Fuerteventura have been explored as potential source of REE. Two main complexes constituted by ultramafic to salic rocks and carbonatitas are present in the island: the Puerto de la Pea-Cueva de Lobos (= 60 Ma) in the western centerpoint and the Esquinzo (=30 Ma) in the northern zone. The calciocarbonatites (sovites and alwikites), formed in the last crystallization phases of these complexes, show the highest values of REE (511-7,372 ppm) and these elements mainly are associated with carbonates (synchysite), phosphates (REE apatite), silicates (allanite). (Author) 17 refs.

  9. Structural controls and evolution of gold-, silver-, and REE-bearing copper-cobalt ore deposits, Blackbird district, east-central Idaho: Epigenetic origins

    Science.gov (United States)

    Lund, K.; Tysdal, R.G.; Evans, K.V.; Kunk, M.J.; Pillers, R.M.

    2011-01-01

    The Cu-Co ± Au (± Ag ± Ni ± REE) ore deposits of the Blackbird district, east-central Idaho, have previously been classified as Besshi-type VMS, sedex, and IOCG deposits within an intact stratigraphic section. New studies indicate that, across the district, mineralization was introduced into the country rocks as a series of structurally controlled vein and alteration systems. Quartz-rich and biotite-rich veins (and alteration zones) and minor albite and siderite veinlets maintain consistent order and sulfide mineral associations across the district. Both early and late quartz veins contain chalcopyrite and pyrite, whereas intermediate-stage tourmaline-biotite veins host the cobaltite. Barren early and late albite and late carbonate (generally siderite) form veins or are included in the quartz veins. REE minerals, principally monazite, allanite, and xenotime, are associated with both tourmaline-biotite and late quartz veins. The veins are in mineralized intervals along axial planar cleavage, intrafolial foliation, and shears.

  10. Mineralogy and geochemistry of REE-Zr-Nb mineralised nepheline syenites in the peralkaline Ilímaussaq complex, South Greenland

    DEFF Research Database (Denmark)

    Borst, Anouk Margaretha

    -related Gardar province and comprises a series of highly unusual magmatic rocks described as agpaitic nepheline syenites. Agpaitic rocks are characterised by the presence of complex Na-Zr-Ti-silicates such as eudialyte and rinkite instead of common accessory Zr and Ti minerals like zircon and titanite....... The present study focusses on the lower part of the magmatic sequence in the southern part of the complex (Kringlerne), comprising a c. 250 m thick sequence of spectacularly layered syenites called kakortokites. The kakortokites are of particular interest for their enrichment in Zr, Nb, Ta and REE, largely...... potential of these rocks. It is shown that widespread hydrothermal alteration of primary magmatic eudialyte has led to the formation of fine-grained intergrowths of secondary Zr, Nb and REE phases. The alteration was not associated with significant loss or gain of the valuable metals, although the increased...

  11. REE, Uranium (U) and Thorium (Th) contents in Betula pendula leaf growing around Komsomolsk gold concentration plant tailing (Kemerovo region, Western Siberia, Russia)

    Science.gov (United States)

    Yusupov, D. V.; Karpenko, Yu A.

    2016-09-01

    The article deals with the research findings of peculiarities of REE, Uranium and Thorium distribution in the territory surrounding the tailing of former Komsomolsk gold concentration plant according to the data from Betula pendula leaf testing. In the leaf element composition the slight deficiency of MREE and substantial excess of HREE are presented. In the nearest impacted area around the tailing, La, Yb, U and Th content, and Th/U ratio are lower than in the distant buffer area. It is shown, that value of Th/U ratio and REE can be an indicator for geochemical transformations of technogenic landscapes in mining districts. The results of the research can be used for biomonitoring of the territory around the tailing.

  12. Strong Input and Removal of Rare Earth Elements (REEs) Affect Dissolved Nd Isotope Composition of Seawater in the Panama Basin and the Eastern Equatorial Pacific

    Science.gov (United States)

    Frank, M.; Bosse, L. M.; Grasse, P.; Pahnke, K.; Hathorne, E. C.

    2014-12-01

    The distributions of dissolved REEs and Nd isotopes are controlled by inputs from land and water mass mixing. We present new data from the Panama Basin in the Eastern Equatorial Pacific (EEP) extending previous studies in the frame of the German SFB 754 project. The samples were taken following GEOTRACES protocols along a section from close to the Panamanian coast into the deep Panama Basin during FS Meteor cruise M90 in October/November 2012. Elevated Nd concentrations near 13 pmol/kg are found at the surface, which rapidly decrease to a subsurface minimum of 8 pmol/kg near 100m depth and then increase with water depth reaching maximum values of 18 pmol/kg at 3000 m water depth. However, these deep water concentrations are more than a factor of 2 lower than observed for North Pacific Deep Water (NPDW), which is the prevailing Pacific deep water mass at the sampling locations. All the REEs are depleted compared to NPDW suggesting that efficient uptake and scavenging dominate compared to release from remineralized particles. The surface waters show the most radiogenic Nd isotope values (ɛNd = +4.3) so far obtained globally. In combination with the Nd concentration maxima at the surface this suggests riverine dissolved and fine grained particulate inputs from southern Panama and Colombia where highly radiogenic volcanic rocks are exposed. Elevated ɛNd values above -1 in the entire water column are more radiogenic than in NPDW in the Central Pacific and in waters further south in the EEP, which confirms that release of REEs from the sinking volcanogenic material affects the entire water column. These data clearly document that significant inputs from land combined with efficient scavenging and removal in surface and deep waters control the distribution of REEs and Nd isotopes in the Panama Basin and the adjacent EEP (Grasse et al., 2012), which also has important implications for the distribution of other trace metals.

  13. Redistribution of REE, Pb and U by supergene weathering studied from in-situ isotopic analyses of the Bangombé natural reactor, Gabon

    Science.gov (United States)

    Kikuchi, M.; Hidaka, H.; Horie, K.; Gauthier-Lafaye, F.

    2007-10-01

    The isotopic analyses of rare earth elements (REE), Pb and U in several kinds of minerals from the clay and black shale layers above the Bangombé natural reactor, Gabon, were performed using a sensitive high-resolution microprobe (SHRIMP) to investigate the migration and retardation processes of fission products released from the reactor. REE isotopic data of the secondary minerals found in clays and black shales show that most of fission products were effectively trapped in the clays and not distributed into the black shales over the clays, which reveals that the clays play an important role in preventing fission products from spreading. Zircon crystals in the clays heterogeneously contain high-U regions (up to 28.3 wt%) with normal 235U/ 238U ratios (=0.00725) and significant amounts of fissiogenic REE, which suggest the occurrence of significant chemical fractionation between REE and U during the dissolution of reactor uraninite and the recrystallization of secondary U minerals. The Pb data suggest that galena grains in the clays were also formed by the mixing of the two components during a recent alteration event, and that a significant amount of Pb was derived from 2.05-Ga-old original uraninite rather than reactor uraninite. The U-Pb systematics of zircon provide chronological information on the old igneous activity associated with the basement rock formation at 2.8 Ga and geochemical evidence of the incomplete mixing of independent Pb and U sources. This result is consistent with previous chronological results in this area.

  14. Removal of high-salinity matrices through polymer-complexation-ultrafiltration for the detection of trace levels of REEs using inductively coupled plasma mass spectrometry.

    Science.gov (United States)

    Duan, Hualing; Lin, Jijun; Gong, Zhenbin; Huang, Jiahua; Yang, Shifeng

    2015-10-01

    The polymer-complexation-ultrafiltration (PCUF) technique was applied to separate trace levels of rare earth elements (REEs), including scandium, yttrium and the lanthanides, from high-salinity matrices prior to their determination by inductively coupled plasma mass spectrometry (ICP-MS). The REEs were converted into REE-polymer complexes using the water-soluble polymer polyacrylic acid (PAA) at a specified pH, retained on the ultrafiltration membrane of centrifugal filter units, and finally eluted using diluted nitric acid to achieve separation from matrices with relatively high levels of various inorganic ions, such as sodium, potassium, calcium, magnesium, and chlorine ions. Numerous factors affecting the PCUF efficiency were optimized. The optimal conditions included the addition of 30 mg L(-1) of PAA, a pH of 7.5, a reaction time of 40 min at room temperature, and 5.0 mL of 3% nitric acid (v/v) eluent. Under these conditions, the analytes were quantitatively separated and recovered, with a resulting relative standard deviation (RSD) of less than 4.0% (0.05 µg L(-1), n=5) and standard addition recoveries between 89.2% (La) and 95.8% (Sm) for matrices of various salinities. The blank samples for the method ranged from 0.0003 µg L(-1) (Dy) to 0.0031 µg L(-1) (Sc), and the limits of quantification (LOQs, 10σ) were between 0.0006 µg L(-1) (Dy) and 0.0026 µg L(-1) (Sc). Furthermore, the salinity of the sample exhibited no effect on the REE-polymer complex formation process. Finally, the method was successfully applied for the determination of trace levels of dissolved Sc, Y, and lanthanides in coastal and estuarine seawater samples.

  15. A Study of REE and Pb,Sr and Nd Isotopes in Garnet—Lherzolite Xenoliths from Mingxi,Fujian Province

    Institute of Scientific and Technical Information of China (English)

    黄婉康; BASU,A.R.; 等

    1993-01-01

    The REE and Pb ,Sr,Nd isotopes in three xenoliths from limburgite and scoria-breccias,including spinel-lherzolite,spinel-gamet-1herzolite and phlogopite-gamet-1herzolite,were analysed.The REE contentso of the xenoliths are 1.3 to 3.3 times those of the chondrites with their REE pattems characterized by weak LREE depletion.The 143Nd/144Nd values of whole rocks and minerals range from 0.51306 to 0.51345 with εNd=+8.2-+15.8,206Pb/204Pb<18.673,and 207Pb/204Pb<15.574,All this goes to show that the upper mantle in Mingxi at the depth of 67-82km is a depleted mantle of MORB type,with 87Sr/86Sr ratios 0.70237-0.70390.In Nd-Sr diagram the data points of whole rocks are all out of the mantle array,implying that the xenoliths from Mingxi have more radiogenic Sr isotopes than those of the mantle array.

  16. Dynamics of REE accumulation and fractionation in the subcolloidal fraction of bottom sediments in the Razdol'naya River-Amur Bay section, Sea of Japan

    Science.gov (United States)

    Polyakov, D. M.

    2016-05-01

    The REE contents (La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu) are determined by atomic emission spectroscopy in the subcolloidal fraction of bottom sediments in the Razdol'naya River-Amur Bay section. The mean contents of lanthanides in soils and river bottom sediments (before the mixing zone) are calculated. The increase in REE content and the fractioning in the series from light to middle and heavy REE in sediments of different estuary zones (river, water mixing, and marine), with the latter related to flocculation, sorption on iron and manganese hydroxides, clay minerals (hydromica, smectites), and lifetime accumulation of marine plankton, are dtermined. Via extraction of 0.5 N sodium hydroxide solution, the content of lanthanides associated with humic substances of subcolloidal fraction from the Amur Bay sediments are determined: 1.3 to 8.2% of La; 1.1 to 11% of Ce; and 0.3 to 1.5 of Gd.

  17. Fluid-mediated alteration of (Y,REE,U,Th)-(Nb,Ta,Ti) oxide minerals in granitic pegmatite from the Evje-Iveland district, southern Norway

    Science.gov (United States)

    Duran, Charley J.; Seydoux-Guillaume, Anne-Magali; Bingen, Bernard; Gouy, Sophie; de Parseval, Philippe; Ingrin, Jannick; Guillaume, Damien

    2016-10-01

    We document the textural relations and chemical composition of (Y,REE,U,Th)-(Nb,Ta,Ti) oxide minerals in a granitic pegmatite from the Evje-Iveland district, southern Norway, using a combination of scanning and transmission electron microscopy, electron probe micro-analysis and infrared absorption spectroscopy. The (Y,REE,U,Th)-(Nb,Ta,Ti) oxide mineral is euxenite, which is strongly radiation damaged and surrounded by radial fractures. Within euxenite grains, three domains of distinct composition comprising unaltered, intermediate and altered euxenite, have been identified. In most cases pyrochlore occurs as corroded grain boundaries around euxenite and within relict fractures. Intermediate and altered euxenite are depleted in U, Pb, Ti, Nb, and Y, but enriched in Si and Ca relative to unaltered euxenite. Pyrochlore is also enriched in Fe, Pb, Zr and LREE relative to all euxenite phases. Altered domains of euxenite have deficient analytical totals and contain O-H. These domains are metamict and contain nanopores and nanodomains enriched in U and Ca. We suggest that as radiation damage accumulated in euxenite, radial fractures developed around the euxenite grains, thus allowing fluid infiltration. In the presence of fluid, euxenite was replaced by secondary euxenite then pyrochlore, owing to dissolution-precipitation and diffusion reactions. During alteration, U and the strategic metals Nb, Ti, and REE were mobilized at both the nanoscale and the scale of the pegmatite.

  18. 大新铀矿床稀土元素地球化学特征及成矿机理%REE geochemistry and genesis of Daxin uranium deposit

    Institute of Scientific and Technical Information of China (English)

    李治兴; 漆富成; 何中波; 张字龙

    2011-01-01

    通过对大新铀矿床各构造地球化学带的稀土元素特征参数、球粒陨石标准化配分曲线以及分层聚类谱系的分析,笔者对该矿床铀源和成矿机理进行了探讨.研究表明,大新矿床的铀主要来自于寒武纪地层,泥盆纪地层虽然有一定的预富集作用,但以作为有利的储矿空间为主.成矿过程为地下水在燕山早期和晚期构造运动产生的构造热和岩体加热下形成地下热水,并在构造驱动下沿着沟通寒武系和泥盆系的F2主断层向上运移,萃取寒武系中的活性铀,在F2正断层的次级断层F13、F23、F33等控制的富含有机质、黄铁矿的还原环境中沉淀富集,形成铀矿床.%Through the analysis on typical REE parameters, chondrite-normalized REE patterns and hierarchical cluster analysis of rocks in the structural-geochemical zonation in Daxin uranium deposit, the paper discusses the uranium source and genesis. The study shows that the uranium source mainly came from Cambrian System. The Devonian System is maily as the favorable room for saving ores in addition to pre-concentrated room for uranium. Underground water resulted from early and late Yanshanian movement and the heating of volcanic rock was turned into geothermal water and it was moved upward by the force of tectonic movement. The geothermal water mainly extracted active uranium from the Cambrian rocks, then moved upward along main regional fault (F2) connecting the Cambrian rocks and the Devonian rocks until it arrived in structural fracture zone which was controlled by secondary faults ( F13, F23, F33) .At last, the uranium element in geothermal water was precipitated and concentrated into the uranium deposit in reducing environment of enriched organic material and pyrite.

  19. Origin of the eclogitic clasts with graphite-bearing and graphite-free lithologies in the Northwest Africa 801 (CR2) chondrite: Possible origin from a Moon-sized planetary body inferred from chemistry, oxygen isotopes and REE abundances

    Science.gov (United States)

    Hiyagon, H.; Sugiura, N.; Kita, N. T.; Kimura, M.; Morishita, Y.; Takehana, Y.

    2016-08-01

    In order to clarify the origin of the eclogitic clasts found in the NWA801 (CR2) chondrite (Kimura et al., 2013), especially, that of the high pressure and temperature (P-T) condition (∼3 GPa and ∼1000 °C), we conducted ion microprobe analyses of oxygen isotopes and rare earth element (REE) abundances in the clasts. Oxygen isotopic compositions of the graphite-bearing lithology (GBL) and graphite-free lithology (GFL) show a slope ∼0.6 correlation slightly below the CR-CH-CB chondrites field in the O three-isotope-diagram, with a large variation for the former and almost homogeneous composition for the latter. The average REE abundances of the two lithologies show almost unfractionated patterns. Based on these newly obtained data, as well as mineralogical observations, bulk chemistry, and considerations about diffusion timescales for various elements, we discuss in detail the formation history of the clasts. Consistency of the geothermobarometers used by Kimura et al. (2013), suggesting equilibration of various elements among different mineral pairs, provides a strong constraint for the duration of the high P-T condition. We suggest that the high P-T condition lasted 102-103 years. This clearly precludes a shock high pressure (HP) model, and hence, strongly supports a static HP model. A static HP model requires a Moon-sized planetary body of ∼1500 km in radius. Furthermore, it implies two successive violent collisions, first at the formation of the large planetary body, when the clasts were placed its deep interior, and second, at the disruption of the large planetary body, when the clasts were expelled out of the parent body and later on transported to the accretion region of the CR chondrites. We also discuss possible origin of O isotopic variations in GBL, and presence/absence of graphite in GBL/GFL, respectively, in relation to smelting possibly occurred during the igneous process(es) which formed the two lithologies. Finally we present a possible

  20. Sedimentary carbonate-hosted giant Bayan Obo REE-Fe-Nb ore deposit of Inner Mongolia, China; a cornerstone example for giant polymetallic ore deposits of hydrothermal origin

    Science.gov (United States)

    Chao, E.C.T.; Back, J.M.; Minkin, J.A.; Tatsumoto, M.; Junwen, Wang; Conrad, J.E.; McKee, E.H.; Zonglin, Hou; Qingrun, Meng; Shengguang, Huang

    1997-01-01

    Detailed, integrative field and laboratory studies of the textures, structures, chemical characteristics, and isotopically determined ages and signatures of mineralization of the Bayan Obo deposit provided evidence for the origin and characteristics favorable for its formation and parameters necessary for defining giant polymetallic deposits of hydrothermal origin. Bayan Obo is an epigenetic, metasomatic, hydrothermal rare earth element (REE)-Fe-Nb ore deposit that is hosted in the metasedimentary H8 dolostone marble of the Middle Proterozoic Bayan Obo Group. The metasedimentary sequence was deposited on the northern continental slope of the North China craton. The mine area is about 100 km south of the suture marking Caledonian subduction of the Mongolian oceanic plate from the north beneath the North China craton. The mineralogy of the deposit is very complex, consisting of more than 120 different minerals, some of which are epigenetic minerals introduced by hydrothermal solutions, and some of which are primary and secondary metamorphic minerals. The major REE minerals are monazite and bastnaesite, whereas magnetite and hematite are the dominant Fe-ore minerals, and columbite is the most abundant Nb mineral. Dolomite, alkali amphibole, fluorite, barite, aegirine augite, apatite, phlogopite, albite, and microcline are the most widespread gangue minerals. Three general types of ores occur at Bayan Obo: disseminated, banded, and massive ores. Broad zoning of these ore types occurs in the Main and East Orebodies. Disseminated ores are in the outermost zone, banded ores are in the intermediate zone, and massive ores are in the cores of the orebodies. On the basis of field relations, host rocks, textures, structures, and mineral assemblages, many varieties of these three types of ores have been recognized and mapped. Isotopic dating of monazite, bastnaesite, aeschynite, and metamorphic and metasomatic alkali amphiboles associated with the deposit provides constraints

  1. Validade da equação de Henry e Rees que estima a taxa metabólica de repouso em adolescentes masculinos Validez de la ecuación de Henry y Rees que estima la tasa metabólica de reposo en adolescentes masculinos Validity of the equation of Henry and Rees that estimates the resting metabolic rate in male adolescents

    Directory of Open Access Journals (Sweden)

    Paulo Henrique S. Fonseca

    2011-06-01

    Full Text Available OBJETIVO: Analisar a validade da equação de predição da taxa metabólica de repouso proposta por Henry e Rees (1991 em adolescentes do sexo masculino. MÉTODOS: Estudo transversal, com amostra de conveniência constituída de 52 meninos, entre dez e 17 anos, sendo mensuradas a massa corporal e a calorimetria indireta. A massa corporal foi substituída na equação de Henry e Rees para determinar a taxa metabólica de repouso predita. A calorimetria indireta foi determinada pelos valores do consumo de O2 e produção de CO2, e usada na equação de Weir (1949, considerada método padrão para o cálculo da taxa metabólica de repouso. Todas as medidas foram realizadas pela manhã, com o indivíduo em jejum de seis horas, em posição supina e em repouso muscular. Realizaram-se os seguintes procedimentos estatísticos: teste t pareado; erro constante (com diferença aceita entre as médias OBJETIVO: Analizar la validez de la ecuación de predicción de la tasa metabólica de reposo (TMR propuesta por Henry y Rees (1991 en adolescentes del sexo masculino. MÉTODOS: Estudio transversal, con muestra de conveniencia constituida por 52 niños, entre 10 y 17 años, siendo medidas las variables a continuación: masa corporal y calorimetría indirecta (CI. La masa corporal fue sustituida en la ecuación de Henry y Rees (1991 para determinar la TMR predicha. La CI fue determinada por los valores del consumo de O2 y producción de CO2 y usada en la ecuación de Weir (1949, considerada como método estándar de la TMR. Todas las medidas fueron realizadas por la mañana, con el individuo en ayuno de 6 horas, en posición supina y en reposo muscular. Se realizaron los siguientes procedimientos estadísticos: prueba “t” pareada; error constante (EC - con diferencia aceptada entre los promedios menor que 5% y, para análisis de la concordancia entre los dos métodos, el procedimiento gráfico de Bland y Altman. RESULTADOS: La ecuación propuesta por

  2. Distribution of trace elements including tellurium, gallium, indium, and select REE in sulfide chimneys from Brothers submarine volcano, Kermadec arc

    Science.gov (United States)

    Berkenbosch, H. A.; de Ronde, C. E.; McNeill, A.; Goemann, K.; Gemmell, J. B.

    2011-12-01

    Brothers volcano is a dacitic volcano located along the Kermadec arc, New Zealand, and hosts the NW Caldera hydrothermal vent field perched on part of the steep caldera walls. The field strikes for ~600 m between depths of 1550 and 1700 m and includes numerous, active, high-temperature (max 302°C) chimneys and even more dead, sulfide-rich spires. Chimney samples collected from Brothers show distinct mineralogical zonation reflecting gradients in oxidation state, temperature, and pH from the inner walls in contact with hydrothermal fluids through to the outer walls in contact with seawater. Minerals deposited from hotter fluids (e.g., chalcopyrite) are located in the interior of the chimneys and are surrounded by an external zone of minerals deposited by cooler fluids (e.g., sulfates, sphalerite). Four chimneys types are identified at Brothers volcano based on the relative proportions of chalcopyrite and sulfate layers, and the presence or absence of anhydrite. Two are Cu-rich, i.e., chalcopyrite-rich and chalcopyrite-bornite-rich chimneys, and two are Zn-rich, i.e., sphalerite-rich and sphalerite-chalcopyrite-rich. Barite and anhydrite are common to both Cu-rich chimney types whereas Zn-rich chimneys contain barite only. The main mineral phases in all the chimneys are anhydrite, barite, chalcopyrite, pyrite/marcasite, and sphalerite. Trace minerals include galena, covellite, tennantite, realgar, chalcocite, bornite, hematite, goethite, Pb-As sulfosalts, and Bi- or Au-tellurides. The vast majority of tellurides are trace elements and REE such as In (53.1 ppm), Ga (1870), Y (26), La (21.2), Ce (21), Sm (2.8), Gd (4), and Yb (3) in Brothers chimneys. To better understand the mineral associations and zonation of these and other trace elements within the chimney walls, we have undertaken element mapping on the four different chimneys types with both X-Ray fluorescence microscopy using synchrotron radiation and with Laser Ablation Inductively Coupled Plasma Mass

  3. Petrological mineralogical and geochemical characterization of the granitoids and fracture fillings developed in Ratones Mines (Spain); Caracterizacion petrologica, mineralogica, geoquimica y evaluacion del comportamiento geoquimico de las REE en la fase solida (granitoides y rellenos fisurales) del sistema de interaccion agua-roca delentorno de la Mina Ratones

    Energy Technology Data Exchange (ETDEWEB)

    Buil Gutierrez, B. [Ciemat. Madrid (Spain)

    2002-07-01

    The petrological, mineralogical and geochemical characterisation of the granitoids and fracture fillings developed in the Ratones Mine (Caceres, Spain) has been done in order to understand rock-water interaction processes which control water geochemical parameters. Special interest has been devoted to the analysis and interpretation of REE patterns in the solid phase (granitoids and fracture fillings) because they constitute geochemical tracers in water-rock interaction process. Moreover, REE are considered as actinide analogues. In order to characterise the solid phase (granitoids and fracture fillings) several investigation scales (system, outcrop, whole rock, mineral and geochemical components) have been considered and different types of samples have been analysed. These factors control the methodological approach used in this investigation. The analytical methods we have used in this investigation are microscope, qualitative and semi-quantitative methods (XRD, SEM,EDAX) and quantitative methods (ICP-MS, XRF, EM, LAM-IC-MS). The bulk of the granitoids located around the Ratones Mine Belongs to the alkaline feldspar granite-sienogranite lihotype and they show a peraluminous and subalkaline pattern. From the mineralogical point of view, they are composed by quartz, K-feldspar (Or>90%), showing sericitation, moscovitization and turmolinization altherations, alkaline plagioclase (An-=-3%), usually altered to sericite, saussirite and less frequently affected by moscovitization processes, Fe-Al biotite, frequently affected by chloritization processes and sometimes replaced by muscovite, and finally muscovite (>2% celadonite and <4% paragonite) both of primary and secondary origin. The differences observed between the different lithotypes are related with the modal proportion of the principal minerals,with the presence or absence of certain accessory minerals ( turmaline, cordierite), with specific textural patterns, grain size and also with the richness in specific

  4. Fluid-driven destabilization of REE-bearing accessory minerals in the granitic orthogneisses of North Veporic basement (Western Carpathians, Slovakia)

    Science.gov (United States)

    Ondrejka, M.; Putiš, M.; Uher, P.; Schmiedt, I.; Pukančík, L.; Konečný, P.

    2016-10-01

    A variety of rare earth elements-bearing (REE) accessory mineral breakdowns were identified in granitic orthogneisses from the pre-Alpine basement in the Veporic Unit, Central Western Carpathians, Slovakia. The Ordovician granitic rocks were subjected to Variscan metamorphic-anatectic overprint in amphibolite facies. Chemical U-Th-Pb dating of monazite-(Ce) and xenotime-(Y) reveal their primary magmatic Lower to Middle Ordovician age (monazite: 472 ± 4 to 468 ± 6 Ma and xenotime: 471 ± 13 Ma) and/or metamorphic-anatectic Variscan (Carboniferous, Visean) age (monazite: 345 ± 3 Ma). Younger fluid-rock interactions caused breakdown of primary magmatic and/or metamorphic-anatectic monazite-(Ce), xenotime-(Y), fluorapatite and allanite-(Ce). Fluid-induced breakdown of xenotime-(Y) produced numerous tiny uraninite inclusions within the altered xenotime-(Y) domains. The monazite-(Ce) breakdown produced secondary egg-shaped coronal structures of different stages with well-developed concentric mineral zones. Secondary sulphatian monazite-(Ce) (up to 0.15 apfu S) occasionally formed along fluorapatite fissures. Localized fluorapatite and monazite-(Ce) recrystallization resulted in a very fine-grained, non-stoichiometric mixture of REE-Y-Fe-Th-Ca-P-Si phases. Finally, allanite-(Ce) decomposed to secondary REE carbonate minerals (members of the bastnäsite and synchysite groups) and calcite in some places. Although the xenotime alteration and formation of uraninite inclusions is believed to be the result of dissolution-reprecipitation between early magmatic xenotime and late-magmatic granitic fluids, the monazite, apatite and allanite breakdowns were driven by metamorphic hydrothermal fluids. While earlier impact of post-magmatic fluids originated probably from Permian acidic volcanic and microgranitic veins crosscutting the orthogneisses, another fluid-rock interaction event most likely occurred during Late Cretaceous metamorphism in the Veporic basement and covering

  5. Ocean circulation and freshwater pathways in the Arctic Mediterranean based on a combined Nd isotope, REE and oxygen isotope section across Fram Strait

    Science.gov (United States)

    Laukert, Georgi; Frank, Martin; Bauch, Dorothea; Hathorne, Ed C.; Rabe, Benjamin; von Appen, Wilken-Jon; Wegner, Carolyn; Zieringer, Moritz; Kassens, Heidemarie

    2017-04-01

    The water masses passing the Fram Strait are mainly responsible for the exchange of heat and freshwater between the Nordic Seas and the Arctic Ocean (the Arctic Mediterranean, AM). Disentangling their exact sources, distribution and mixing, however, is complex. This work provides new insights based on a detailed geochemical tracer inventory including dissolved Nd isotope (εNd), rare earth element (REE) and stable oxygen isotope (δ18O) data along a full water depth section across Fram Strait. We find that Nd isotope and REE distributions in the open AM primarily reflect lateral advection of water masses and their mixing. Seawater-particle interactions exert important control only above the shelf regions, as observed above the NE Greenland Shelf. Advection of northward flowing warm Atlantic Water (AW) is clearly reflected by an εNd signature of -11.7 and a Nd concentration ([Nd]) of 16 pmol/kg in the upper ∼500 m of the eastern and central Fram Strait. Freshening and cooling of the AW on its way trough the AM are accompanied by a continuous change towards more radiogenic εNd signatures (e.g. -10.4 of dense Arctic Atlantic Water). This mainly reflects mixing with intermediate waters but also admixture of dense Kara Sea waters and Pacific-derived waters. The more radiogenic εNd signatures of the intermediate and deep waters (reaching -9.5) are mainly acquired in the SW Nordic Seas through exchange with basaltic formations of Iceland and CE Greenland. Inputs of Nd from Svalbard are not observed and surface waters and Nd on the Svalbard shelf originate from the Barents Sea. Shallow southward flowing Arctic-derived waters (freshwater of up to ∼6%. In addition to these observations, this study shows that the pronounced gradients in εNd signatures and REE characteristics in the upper water column provide a reliable basis for assessments of shallow hydrological changes within the AM.

  6. REE distribution in zircon from reference rocks of the Arctic region: Evidence from study by the LA-ICP-MS method

    Science.gov (United States)

    Nikolaev, A. I.; Drogobuzhskaya, S. V.; Bayanova, T. B.; Kaulina, T. V.; Lyalina, L. M.; Novikov, A. I.; Steshenko, E. N.

    2016-10-01

    The results of the LA-ICP-MS analysis of the concentrations of REEs, U, Th, and Hf in zircon from Paleo- and Neoarchean reference rocks of the Kola region (garnet-amphibole gneiss, basic and acid granulites, and granite pegmatite) are reported. A new methodology of the study of accessory zircons has been validated and modified. The accuracy of the results is confirmed by analysis of standard zircons Temora 1 and 91 500 and by comparison with the data obtained in other laboratories.

  7. Suzuki-Ree群的自同构群的一个新刻画%A New Characterization of the Automorphism Groups of Suzuki-Ree Groups

    Institute of Scientific and Technical Information of China (English)

    肖芳芳; 曹洪平; 陈贵云

    2013-01-01

    证明了Suzuki-Ree群2F4(q),q=2f,2G2(q),g=3f及Tits单群2F4(2)'的自同构群可由阶分量刻画,其中f=3s,s为正整数.%We show that the automorphism groups of Suzuki-Ree groups 2F4(q),q =2f,2G2(q),q =3f and the Tits simple Group 2F4(2)',which f =3s,s be positive integer are characterized by their order components.

  8. Britholite, monazite, REE carbonates, and calcite: Products of hydrothermal alteration of allanite and apatite in A-type granite from Stupné, Western Carpathians, Slovakia

    Science.gov (United States)

    Uher, Pavel; Ondrejka, Martin; Bačík, Peter; Broska, Igor; Konečný, Patrik

    2015-11-01

    An uncommon assemblage of primary and secondary accessory REE minerals was identified in a Permian A-type granite clast in polymict conglomerates intercalated in the Cretaceous flysch sequence of the Pieniny Klippen Belt, Western Carpathians, northwest Slovakia. A detailed electron-microprobe study of the granite reveals extensive subsolidus alteration of primary magmatic allanite-(Ce) to ferriallanite-(Ce) and fluorapatite. The Y, Ce-rich fluorapatite was replaced by the dissolution-reprecipitation process to the britholite group mineral members: fluorbritholite-(Y), britholite-(Y), fluorcalciobritholite, and its hydroxyl-dominant analogue ("calciobritholite"). Britholite-(Y) contains up to 5.2 wt.% ThO2 (0.15 apfu Th); the highest Th content yet reported in naturally occurring Y-dominant britholites. Moreover, the alteration of (ferri)allanite-(Ce) resulted to complex pseudomorphs and overgrowths, including mainly REE carbonate phases: [synchysite-(Ce) to its hydroxyl-dominant analogue "hydroxylsynchysite-(Ce)", bastnäsite-(Ce)] and calcite, rarely monazite-(Ce), epidote, clinochlore, titanite, TiO2 phase, and pseudorutile. In some cases, secondary carbonate minerals (mainly synchysite and calcite) replaced a substantial part of former allanite crystals. Moreover, primary magmatic biotite (annite) was partly transformed to acicular stilpnomelane. Textural and compositional data indicate extensive replacement and breakdown of the primary magmatic allanite and apatite by aqueous fluids rich in fluorine and carbon, liberated during a younger post-magmatic, low-temperature hydrothermal-metamorphic overprint of the granite.

  9. 加拿大安大略省奈恩铜镍矿区岩相学、矿相学及稀土元素地球化学特征%Petrographic, ore microscope and REE geochemical characteristics of the Narin Cu- Ni mining area, Ontaria, Canada

    Institute of Scientific and Technical Information of China (English)

    胥迎红; 王晨昇; 王向兰

    2012-01-01

    The development of Nairn copper - nickel mining area is under the control of the regional Nipissing suite. I , Ⅱ rock complex in the Nairn property mainly is composed of gabbro phase, pyroxenite phase, diorite phase. Copper - nickel mineralization in the Nairn property is mainly related to gabbro phase which dominates the mineralization distribution. Ore texture is composed of sidero-nitic texture,the teardrop -shaped texture,patchy texture,which suggests that minerals were formed in a complex environment during the process of early deep liquation. Based on the REE analysis of samples from No. 1 complex, it is found that: ΣREE varys largely from 26.65 to 241.00; LREE enriches and ((La/Yb) N varys from 1.75 to 10.30); REE distribution pattems is part of the right - inclined distribution patterns,which is the result of deep magmatic differentiation,which implya greatly potential for mineralization.%奈恩铜镍矿区受区域上的尼帕辛(Nipissing)岩套控制,与萨德贝里(Sudbury)火成杂岩体无关.Ⅰ、Ⅱ岩体主要由辉长岩相、辉石岩相、闪长岩相组成.区内铜镍矿化主要与辉长岩相有关,受其控制.矿石结构以海绵陨铁结构和水滴状、团斑状结构为主,属于岩浆深部熔离—贯入成矿特征.通过Ⅰ号岩体样品的稀土元素测试分析发现,ΣREE变化大(26.65~241.00),富集LREE且(La/Yb)N为1.75 -10.30,球粒陨石标准化配分曲线属右倾型,这是其深部岩浆充分分异的结果,对成矿非常有利.

  10. LATERITE FORMATION PROCESS IN SOUTHERN CHINA AND ITS RARE EARTH ELEMENT (REE) GEOCHEEMISTRY%南方红土形成过程及其稀土元素地球化学

    Institute of Scientific and Technical Information of China (English)

    杨元根; 刘丛强; 袁可能; 何振立

    2000-01-01

    南方不同红土的化学蚀变指数(CIA),硅铝系数 、铝铁系数 硅铁铝系数 反映红土的形成经历了脱钙、脱碱基和初级脱硅富铝富铁3个主要的 风化阶段;稀土在前两个阶段中主要发生淋失,而在后一阶段中富集,其配分曲线具Eu亏损的轻稀土显著富集型特征。红土中稀土元素的赋存状态以晶格相为主,主要与基岩密切有关,而其它赋存状态则与红土化过程紧密相连。红土中可溶态稀土含量的高低是风化作用强度的有效指标。%Chemical index of alteration (CIA) for different laterites released that lateritesderived from basalt, Quaternary red clay and gneiss hold the highest CIA values, followed by granite laterites, then limestone and sandstone; other parameters ratio exposed the results which agreed well with that of CIA; Normalized transitions for major element components were carried out to removethe false phenomena of enrichment or loss of inert components from which threestages for laterization process can be inferred, that is, leaching stage of CaO followed by leaching of and primary desilicification with Al-enrichment, then the stage of desilicification and Fe and Al-enrichment. Total REE contents in laterites were much higher than that in their basal rocks, andgneiss, limestone and granite laterites possessed the highest contents of total REE butlowest in sediments rich in quartz, t tests show no obviously REE content vahanceindifferent laterite horizons; Soluble REE richened apparently in the lower horizons inlaterite profiles, varied a lot with their derived basal rocks and extremely obviouslyexponential relation can be observed between total REE and soluble REE also extremelyobviously positive relations can exist for soluble REE with CIA values and claycontents while extremely obviously negative relations with organic matter, pH values and milos, which means soluble REE contents can be an effective indicator for laterization

  11. Alteration of Eudialyte and implications for the REE, ZR, and NB resources of the layered Kakortokites in the ILÍMAUSSAQ intrusion, South West Greenland

    DEFF Research Database (Denmark)

    Borst, Anouk Margaretha; Waight, Tod Earle; Smit, Matthijs Arjen

    2014-01-01

    with late‐stage magmatic, presumably Na‐ and F‐ rich aqueous fluids. The alteration effectively fractionates the major components into the secondary minerals, producing separate Zr‐, Nb and REE‐ phases, leading to an increased complexity of the mineralisation and potential ore recovery.......The layered kakortokites in the southern part of the Ilímaussaq Intrusion are of great economic interest due to their high concentrations of REE, Zr, Nb and Ta. The prospective metals are largely contained in eudialyte, a complex sodium‐zirconosilicate and one of the major cumulus phases. Eudialyte......‐group minerals are easily extracted from the host rock through magnetic separation, and contain 12 wt% ZrO2, 2 % TRE2O3 and 1% Nb2O5 on average. Petrographic investigations show that a large fraction of eudialyte at Ilímaussaq is replaced by complex aggregates of secondary minerals as a result of interaction...

  12. Re-interpretation of zircon date in a carbonatite dyke at the Bayan Obo giant REE-Fe-Nb deposit,China

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    @@ Recent re-valuation of the dating of the carbonatite dykes associated with the REE-Fe-Nb giant deposit at Bayan Obo has revealed an anomaly with one of the dates. Inspection of the post-1990 literature for the carbonatite dykes and H8 dolomite rocks and ores of Bayan Obo provides age data in the range 1223 +65 Ma to 1656 Ma, as Table 1 shows. Since Sm and Nd are relatively immobile elements, most of the Sm-Nd dates are considered to be little changed by the subsequent mineralization processes. That the dates occur in two clusters, 1656 ~ 1500 Ma and 1312 ~ 1223 Ma might refer to two related periods of carbonatitic magmatic activity, but that is not relevant at this moment.

  13. An introduction of Markov chain Monte Carlo method to geochemical inverse problems: Reading melting parameters from REE abundances in abyssal peridotites

    Science.gov (United States)

    Liu, Boda; Liang, Yan

    2017-04-01

    Markov chain Monte Carlo (MCMC) simulation is a powerful statistical method in solving inverse problems that arise from a wide range of applications. In Earth sciences applications of MCMC simulations are primarily in the field of geophysics. The purpose of this study is to introduce MCMC methods to geochemical inverse problems related to trace element fractionation during mantle melting. MCMC methods have several advantages over least squares methods in deciphering melting processes from trace element abundances in basalts and mantle rocks. Here we use an MCMC method to invert for extent of melting, fraction of melt present during melting, and extent of chemical disequilibrium between the melt and residual solid from REE abundances in clinopyroxene in abyssal peridotites from Mid-Atlantic Ridge, Central Indian Ridge, Southwest Indian Ridge, Lena Trough, and American-Antarctic Ridge. We consider two melting models: one with exact analytical solution and the other without. We solve the latter numerically in a chain of melting models according to the Metropolis-Hastings algorithm. The probability distribution of inverted melting parameters depends on assumptions of the physical model, knowledge of mantle source composition, and constraints from the REE data. Results from MCMC inversion are consistent with and provide more reliable uncertainty estimates than results based on nonlinear least squares inversion. We show that chemical disequilibrium is likely to play an important role in fractionating LREE in residual peridotites during partial melting beneath mid-ocean ridge spreading centers. MCMC simulation is well suited for more complicated but physically more realistic melting problems that do not have analytical solutions.

  14. Radiochemical neutron activation analysis for 36 elements in geological material: Au, Ag, Bi, Br, Cd, Cs, Ge, In, Ir, Ni, Os, Pd, Rb, Re, Sb, Se, Sn, Te, Tl, U, and Zn as well as Sc, Y, and REE

    Energy Technology Data Exchange (ETDEWEB)

    Anders, E; Wolf, R; Morgan, J W; Ebihara, M; Woodrow, A B; Janssens, M J; Hertogen, J

    1988-01-01

    In lunar and terrestrial rocks and in meteorites, the radiochemical neutron activation method decribed here enables determination of the 21 trace and ultratrace elements Ag, Au, Bi, Br, Cd, Cs, Ga, Ge, In, Ir, Ni, Os, Pd, Rb, Re, Sb, Se, Te, Tl, U, Zn, as well as 13 rare earth elements (REE), Sc and Y. Materials, techniques and procedures are discussed. 81 refs.

  15. Pattern matching

    NARCIS (Netherlands)

    A. Hak (Tony); J. Dul (Jan)

    2009-01-01

    textabstractPattern matching is comparing two patterns in order to determine whether they match (i.e., that they are the same) or do not match (i.e., that they differ). Pattern matching is the core procedure of theory-testing with cases. Testing consists of matching an “observed pattern” (a pattern

  16. An assessment of a handheld X-ray fluorescence instrument for use in exploration and development with an emphasis on REEs and related specialty metals

    Science.gov (United States)

    Simandl, G. J.; Stone, R. S.; Paradis, S.; Fajber, R.; Reid, H. M.; Grattan, K.

    2014-12-01

    Handheld (portable) X-ray fluorescence (pXRF) instruments are designed for use in the exploration for base metals, precious metals, and specialty metals (e.g. rare earth elements (REE), Ta, and Nb) and allow rapid decision-making directly in the field. This paper evaluates the technical merits and limitations of pXRF technology in the exploration for specialty metals using data generated from the analysis of three geochemical standards and a silica blank: Standard Reference Material NIST 2780 from the National Institute of Standards and Technology, Gaithersburg; the Certified Reference Material "TRLK" Rare Earth Ore "CGL 124" from the Mongolia Central Geological Laboratory; the Reference Niobium Ore OKA-1 (CANMET); and a silica blank described as Si (IV) oxide (99.8 % on metal basis) from Alpha Aesar (Ward Hill, MA, USA). The data was acquired over a period of nearly 2 years as a by-product of several distinct specialty metal-related projects using the same pXRF instrument and the same settings. Instrumental analytical accuracy was determined using the percent difference (%diff) between the average concentrations of the pXRF instrument readings and the reported certified values of the standard. Percent relative standard deviation (%RSD) was used as a measure of precision. Smaller %diff and %RSD indicate more accurate and precise data, and the accuracy and precision of the pXRF depended strongly on the elemental concentrations in the standards used. Box and whisker diagrams were used to illustrate characteristics of pXRF data sets (mean, lower and upper quartiles, and range) corresponding to individual standards. The bias of the pXRF determinations (under/overestimation) relative to certified values of individual standards are also depicted on these diagrams. This study indicates that the pXRF was capable of producing readings for Si, K, Al, Fe, Ca, Ti, Pb, Zn, Sr, Ag, Cd, Th, Sb, P, S, Mo, Mn, Mg, As, Nb, Rb, La, Ce, Pr, Nd, and Y within 10 %RSD of the reported

  17. Uranium-lead dating of hydrothermal zircon and monazite from the Sin Quyen Fe-Cu-REE-Au-(U) deposit, northwestern Vietnam

    Science.gov (United States)

    Li, Xiao-Chun; Zhou, Mei-Fu; Chen, Wei Terry; Zhao, Xin-Fu; Tran, MyDung

    2017-06-01

    The Sin Quyen deposit in northwestern Vietnam contains economic concentrations of Cu, Au and LREE, and sub-economic concentration of U. In this deposit, massive and banded replacement ores are hosted in Neoproterozoic metapelite. The paragenetic sequence includes sodic alteration (stage I), calcic-potassic alteration and associated Fe-REE-(U) mineralization (stage II), Cu-Au mineralization (stage III), and sulfide-(quartz-carbonate) veins (stage IV). The Sin Quyen deposit experienced an extensive post-ore metamorphic overprint, which makes it difficult to precisely determine the mineralization age. In this study, zircon and monazite U-Pb geochronometers and the Rb-Sr isochron method are used to constrain the timing of mineralization. Zircon grains in the ore are closely intergrown or texturally associated with hydrothermal minerals of stage II (e.g., garnet, allanite, and hedenbergite). They may contain primary fluid inclusions and display irregular zoning in cathodoluminescence (CL) images. Zircon grains are rich in U (688 to 2902 ppm) and poor in Th (0.2 to 2.9 ppm). Their δ18OV-SMOW values range from 11.9 to 14.0‰, higher than those of typical magmatic zircon. These textural and compositional features imply that zircon precipitated from 18O- and U-rich hydrothermal fluids, coeval with the minerals of stage II. Monazite occurs in close association with stage II magnetite and allanite and has low contents of Th (geological observations suggest that the Cu-Au and Fe-REE ores most likely formed within a single evolved hydrothermal process. In the plot of 87Rb/86Sr vs. 87Sr/86Sr, the composition of bulk-ore and biotite separates from ore lie along a reference line for 30 Ma, which is consistent with the timing of metamorphism in the region. The mineralization age of the Sin Quyen deposit falls within the overall age range (740 to 860 Ma) of the regional Neoproterozoic igneous rocks. This temporal linkage, in combination with the magmatic-like sulfur isotopes of

  18. Polyhedral patterns

    KAUST Repository

    Jiang, Caigui

    2015-10-27

    We study the design and optimization of polyhedral patterns, which are patterns of planar polygonal faces on freeform surfaces. Working with polyhedral patterns is desirable in architectural geometry and industrial design. However, the classical tiling patterns on the plane must take on various shapes in order to faithfully and feasibly approximate curved surfaces. We define and analyze the deformations these tiles must undertake to account for curvature, and discover the symmetries that remain invariant under such deformations. We propose a novel method to regularize polyhedral patterns while maintaining these symmetries into a plethora of aesthetic and feasible patterns.

  19. 镧系元素地球化学效应的一个重要应用——以稀土元素的岩石分类和煤燃烧中的迁移富集过程为例%The effect on geochemistry of the Rare Earth Element: an example of important application in the REE classification for petrology and study for migrating of the REE during the burning of lignite

    Institute of Scientific and Technical Information of China (English)

    杨建业

    2011-01-01

    Form the point of effect on geochiemistry of the REE, the REE distribution of sandstone, coal form ZKA183 - 87 drilling of Dongsheng in Orduos Basin and REE migration law in different ways of buming of lignite which form Xiaolongtan mine in Yunnan, Province were studied by using the date were published. The result shows that, in the REE distribution types of sandstone and coal consistent with previous findings on, at the same time, a new idea about the REE migration duing buming of lignite is put forwarded : whatever the form of combustion, it is same migating way for HREE from lignite to fly and bottom ashes; howere, LREE ,which migrating from lignite to fly and bottom ashes ,is compliant about affected by different combustion: Pulverized coal combustion in power plant, the the larger ionic radius of LREE, the more enriched the fly ash while the larger ionic radius of HREE,the more enriched the bottom ash , and it is easily affected by the combustion of lignite and its burning temperature for REE distribution to fly and bottom ashes in two staged combustion or two non - staged combustion. this study shows that effect on geochemistry of REE, as a new study method, is effective in study REE mode of distribution of various types of geological and it complement the traditional methods for geochemistry of REE.%从镧系元素地球化学效应的角度,探讨了鄂尔多斯盆地东胜ZKA183-87钻孔中砂岩、煤的稀土分布类型和云南小龙潭矿区褐煤不同燃烧方式下的稀土元素迁移和富集规律.研究结果表明,砂岩、煤的稀土分布类型与前人研究结论基本致.发现褐煤燃烧时稀土元素的迁移和富集具有以下特征:无论哪种燃烧方式,褐煤中HREE均以同一种模式向飞灰和底灰中迁移;而LREE向飞灰、底灰迁移富集过程中则要受到燃烧方式的影响,不同的燃烧方式对其迁移模式影响较大;电厂粉煤燃烧时,愈是大离子LREE,愈趋于向飞灰相对富集,愈是大

  20. Specialization Patterns

    DEFF Research Database (Denmark)

    Schultz, Ulrik Pagh; Lawall, Julia Laetitia; Consel, Charles

    2000-01-01

    Design patterns offer many advantages for software development, but can introduce inefficiency into the final program. Program specialization can eliminate such overheads, but is most effective when targeted by the user to specific bottlenecks. Consequently, we propose that these concepts...... are complementary. Program specialization can optimize programs written using design patterns, and design patterns provide information about the program structure that can guide specialization. Concretely, we propose specialization patterns, which describe how to apply program specialization to optimize uses...... of design patterns. In this paper, we analyze the specialization opportunities provided by specific uses of design patterns. Based on the analysis of each design pattern, we define the associated specialization pattern. These specialization opportunities can be declared using the specialization classes...

  1. The Redox Dynamics of Iron in a Seasonally Waterlogged Forest Soil (Chaux Forest, Eastern France) Traced with Rare Earth Element Distribution Patterns

    Science.gov (United States)

    Steinmann, M.; Floch, A. L.; Lucot, E.; Badot, P. M.

    2014-12-01

    The oxyhydroxides of iron are common soil minerals and known to control the availability of various major and trace elements essential for biogeochemical processes. We present a study from acidic natural forest soils, where reducing redox conditions due to seasonal waterlogging lead to the dissolution of Fe-oxyhydroxides, and to the release of Fe to soil water. In order to study in detail the mechanism of redox cycling of Fe, we used Rare Earth Element (REE) distribution patterns, because an earlier study has shown that they are a suitable tool to identify trace metal sources during soil reduction in wetland soils (Davranche et al., 2011). The REE patterns of soil leachates obtained with the modified 3-step BCR extraction scheme of Rauret et al., (1999) were compared with those of natural soil water. The adsorbed fractions (F1 leach), the reducible fraction of the deepest soil horizon H4 (F2 leach, 50-120 cm), and the oxidizable fractions of horizons H2 to H4 (F3 leachs, 24-120 cm) yielded REE patterns almost identical to soil water (see figure), showing that the REE and trace metal content of soil water was mainly derived from the F1 pool, and from the F2 and F3 pools of the clay mineral-rich deep soil horizons. In contrast, the F2 leach mobilized mainly Fe-oxyhydroxides associated with organic matter of the surface soil and yielded REE patterns significantly different from those of soil water. These results suggest that the trace metal content of soil water in hydromorphic soils is primarily controlled by the clay fraction of the deeper soil horizons and not by organic matter and related Fe-oxyhydroxides of the surface soil. Additional analyses are in progress in order to verify whether the REE and trace metals of the deeper soil horizons were directly derived from clay minerals or from associated Fe-oxyhydroxide coatings. Refs cited: Davranche et al. (2011), Chem. Geol. 284; Rauret et al. (1999), J. Environ. Monit. 1.

  2. Detrital zircon U-Pb geochronology, Lu-Hf isotopes and REE geochemistry constrains on the provenance and tectonic setting of Indochina Block in the Paleozoic

    Science.gov (United States)

    Wang, Ce; Liang, Xinquan; Foster, David A.; Fu, Jiangang; Jiang, Ying; Dong, Chaoge; Zhou, Yun; Wen, Shunv; Van Quynh, Phan

    2016-05-01

    In situ U-Pb geochronology, Lu-Hf isotopes and REE geochemical analyses of detrital zircons from Cambrian-Devonian sandstones in the Truong Son Belt, central Vietnam, are used to provide the information of provenance and tectonic evolution of the Indochina Block. The combined detrital zircon age spectra of all of the samples ranges from 3699 Ma to 443 Ma and shows with dominant age peaks at ca. 445 Ma and 964 Ma, along with a number of age populations at 618-532 Ma, 1160-1076 Ma, 1454 Ma, 1728 Ma and 2516 Ma. The zircon age populations are similar to those from time equivalent sedimentary sequences in continental blocks disintegrated from the East Gondwana during the Phanerozoic. The younger zircon grains with age peaks at ca. 445 Ma were apparently derived from middle Ordovician-Silurian igneous and metamorphic rocks in Indochina. Zircons with ages older than about 600 Ma were derived from other Gondwana terrains or recycled from the Precambrian basement of the Indochina Block. Similarities in the detrital zircon U-Pb ages suggest that Paleozoic strata in the Indochina, Yangtze, Cathaysia and Tethyan Himalayas has similar provenance. This is consistent with other geological constrains indicating that the Indochina Block was located close to Tethyan Himalaya, northern margin of the India, and northwestern Australia in Gondwana.

  3. Major, trace and REE geochemistry in contrasted chlorite schist weathering profiles from southern Cameroon: Influence of the Nyong and Dja Rivers water table fluctuations in geochemical evolution processes

    Science.gov (United States)

    Onana, Vincent Laurent; Ntouala, Roger Firmin Donald; Tang, Sylvie Noa; Effoudou, Estelle Ndome; Kamgang, Veronique Kabeyene; Ekodeck, Georges Emmanuel

    2016-12-01

    Three weathering profiles developed on chlorite schists, formations on which little studies have been conducted, were chosen to understand the weathering processes prevailing downslope in Southern Cameroon. The materials nearest to Nyong River at Ayos weather under the influence of the fluctuations of groundwater table and acid rain, while those from Bengbis and Mbalmayo weather under the influence of acid rain. The result is the thickening of materials and weathering profiles, without formation of a nodular ferruginous horizon at Ayos. The Ayos weathered materials (CIA ∼ 92) are the most altered and the least lateritised (IOL ∼ 32). The most stable systems are Hf - U - Nb - Ti - Zr - Mo - W (Bengbis), Yb - U - Nb - Ti - Zr - Hf - Mo - W - Th (Mbalmayo) and Th - Nb - Zr - Hf - Mo - Ta (Ayos). Molybdenum accumulations are important in the studied materials. Uranium accumulations are found only in Mbalmayo. Coarse saprolitic materials at Ayos are the most depleted and fractionated in REE ((La/Yb)N = 0.07, Ce/Ce* = 2.24), while superficial clayey materials are less fractionated. This process is reversed at Bengbis and Mbalmayo. By contrast, weathered materials at Ayos do not show any Eu anomalies (as in Bengbis and Mbalmayo). Weathered materials from Bengbis, nearest to the Dja River, have (La/Yb)N < 1 ratios, indicating the relative immobility of HREE relative to LREE due to xenotime abnormally rich in HREE (HREE-PO4). Weak Ce anomalies (1.05-2.24) are ubiquitous in all the studied materials.

  4. Pattern matching

    OpenAIRE

    Hak, Tony; Dul, Jan

    2009-01-01

    textabstractPattern matching is comparing two patterns in order to determine whether they match (i.e., that they are the same) or do not match (i.e., that they differ). Pattern matching is the core procedure of theory-testing with cases. Testing consists of matching an “observed pattern” (a pattern of measured values) with an “expected pattern” (a hypothesis), and deciding whether these patterns match (resulting in a confirmation of the hypothesis) or do not match (resulting in a disconfirmat...

  5. Albitization and redistribution of REE and Y in IOCG systems: Insights from Moonta-Wallaroo, Yorke Peninsula, South Australia

    Science.gov (United States)

    Kontonikas-Charos, Alkis; Ciobanu, Cristiana L.; Cook, Nigel J.

    2014-11-01

    account for the high ΣREY content (~ 700 ppm) in whole rock. The role of coupled dissolution-reprecipitation reactions (CDRR) is critical for REY (re)distribution within albitized igneous rocks, where REY-release from early magmatic accessories and/or feldspars assists REY-enrichment into late albite. The presence of abundant nanopore-attached inclusions in plagioclase demonstrates the nanoscale nature of CDRR-driven albitization in granitoids, consistent with published experimental work on altered granites. Such porosity offers sites for REY entrapment seen within discrete REY-minerals in new-formed K-feldspar. Similarly, release and uptake of REY, concurrent with albitization, is seen in formation of coarser REY-minerals (xenotime, bastnäsite, synchysite) during CDRR-driven replacement of accessory Fe-Ti-oxides by symplectites of chlorite and hematite. Based on the differences identified between the albitization pathways in igneous and metasedimentary rocks, we discuss how albitization proceeds via a series of complex fluid-mineral reactions, each involving the redistribution, accumulation and retention of REY. These reactions are critical for defining the endowment and deportment of REY in rocks that have undergone sodic alteration. Contrary to previous models, albitization appears controlled by pH rather than redox conditions. Despite regional differences in local geological environment and alteration style across the Olympic Cu-Au Province, albitization, the initiation of hydrothermal alteration, is a pre-requisite stage for REY-enrichment in Iron-Oxide-Copper-Gold (IOCG) systems. REY distribution patterns in feldspars may thus have value in mineral exploration as criteria enabling alteration associated with mineralization to be distinguished from the regional background. Strong albitization without superposition of later potassic alteration may not, however, be automatically linked to the formation of giant IOCG deposits. Albitization enhances rock permeability

  6. Iron isotope and REE+Y composition of the Cauê banded iron formation and related iron ores of the Quadrilátero Ferrífero, Brazil

    Science.gov (United States)

    Mendes, Mônica; Lobato, Lydia M.; Kunzmann, Marcus; Halverson, Galen P.; Rosière, Carlos A.

    2016-04-01

    The Minas Supergroup banded iron formations (BIFs) of the Brazilian Quadrilátero Ferrífero (QF) mineral province experienced multiple deformational events synchronous with hypogene mineralization, which resulted in the metamorphism of BIFs to itabirites and their upgrade to high-grade iron ore. Here, we present rare earth element and yttrium (REE+Y) compositions together with iron isotope ratios of itabirites and their host iron orebodies from 10 iron deposits to constrain environmental conditions during BIF deposition and the effects of hypogene iron enrichment. The REE+Y characteristics of itabirites (positive Eu anomaly and LREE depletion) indicate hydrothermal iron contribution to the Minas basin. Iron isotope data and Ce anomalies suggest BIFs were precipitated by a combination of anoxic biological-mediated ferrous iron oxidation and abiotic oxidation in an environment with free oxygen (such as an oxygen oasis), perhaps related to increase in oxygen concentrations before the Great Oxidation Event (GOE). The similarity of the REE+Y composition of the itabirites from the different QF deformational domains, as well as to other Superior-type BIFs, indicates that the metamorphism and synchronous hydrothermal mineralization did not significantly affect the geochemical signature of the original BIFs. However, iron isotope compositions of iron ore vary systematically between deformational domains of the QF, likely reflecting the specific mineralization features in each domain.

  7. Iron isotope and REE+Y composition of the Cauê banded iron formation and related iron ores of the Quadrilátero Ferrífero, Brazil

    Science.gov (United States)

    Mendes, Mônica; Lobato, Lydia M.; Kunzmann, Marcus; Halverson, Galen P.; Rosière, Carlos A.

    2017-02-01

    The Minas Supergroup banded iron formations (BIFs) of the Brazilian Quadrilátero Ferrífero (QF) mineral province experienced multiple deformational events synchronous with hypogene mineralization, which resulted in the metamorphism of BIFs to itabirites and their upgrade to high-grade iron ore. Here, we present rare earth element and yttrium (REE+Y) compositions together with iron isotope ratios of itabirites and their host iron orebodies from 10 iron deposits to constrain environmental conditions during BIF deposition and the effects of hypogene iron enrichment. The REE+Y characteristics of itabirites (positive Eu anomaly and LREE depletion) indicate hydrothermal iron contribution to the Minas basin. Iron isotope data and Ce anomalies suggest BIFs were precipitated by a combination of anoxic biological-mediated ferrous iron oxidation and abiotic oxidation in an environment with free oxygen (such as an oxygen oasis), perhaps related to increase in oxygen concentrations before the Great Oxidation Event (GOE). The similarity of the REE+Y composition of the itabirites from the different QF deformational domains, as well as to other Superior-type BIFs, indicates that the metamorphism and synchronous hydrothermal mineralization did not significantly affect the geochemical signature of the original BIFs. However, iron isotope compositions of iron ore vary systematically between deformational domains of the QF, likely reflecting the specific mineralization features in each domain.

  8. Pattern recognition

    CERN Document Server

    Theodoridis, Sergios

    2003-01-01

    Pattern recognition is a scientific discipline that is becoming increasingly important in the age of automation and information handling and retrieval. Patter Recognition, 2e covers the entire spectrum of pattern recognition applications, from image analysis to speech recognition and communications. This book presents cutting-edge material on neural networks, - a set of linked microprocessors that can form associations and uses pattern recognition to ""learn"" -and enhances student motivation by approaching pattern recognition from the designer's point of view. A direct result of more than 10

  9. In-situ Trace Element and REE Analysis of Garnet Porphyroblast from the Murphy Belt Drill Core by 213 nm Laser Ablation High Resolution ICPMS

    Science.gov (United States)

    LaTour, T. E.; Ghazi, A. M.

    2001-12-01

    Laser ablation coupled with high resolution inductively coupled plasma mass spectrometry (LA-HR-ICPMS) is a powerful tool for in-situ trace element analysis of solid samples on the micron scale. Recent development of the 213 nm (quintupled) Nd-YAG laser has significantly improved upon the more widely used 266 nm laser. In this study we focus on analysis of zoned garnets from the Murphy Marble Belt with a Universal Platform (UP) Merchantek/New Wave 213 nm laser ablation system, coupled with a Finnigan MAT Element2 high resolution ICPMS which is equipped with the fast scanning power supply magnet. Laser ablation parameters included 60 um spots size, 100% energy level, repetition rate of 20Hz and scanning speed of 16-20 um/seconds. Garnets were analyzed for Mg, Rb, Sr, Y, Zr, Nb, Hf and REE and the data used here were obtained by using a line scan across the diameter of the garnet porphyroblasts. Aluminous schist from drill core from the Murphy Marble Belt of the Western Blue Ridge of Georgia contains two generations of garnet, gt I and gt II. Gt II occurs as stand-alone grains and as overgrowths on gt I. Gt I grew in conjunction with development of biotite (bi) schistosity. Gt-bi geothermometry yields 512-531oC for gt I, consistent upper greenschist metamorphism. Growth of gt I was followed by growth of gt II, kyanite (ky), and staurolite (st), in turn followed by growth of sillimanite (si), large muscovite (ms) porphyroclasts, (and gt II?), associated with a high-T mylonitic event in which plagioclase and aggregates of ky+st+bi were converted to porphyroclasts, lying in a medium grained si-ms-bi schistosity. This was followed by a retrograde mylonitic event which partially converted si, ky, st, and large ms to fine grained ms schistosity which is the dominant schistosity in the rocks. Gt II is distinctly higher in CaO and lower in MnO than gt I, suggesting that it grew under high pressure, perhaps resulting from overthrusting which formed the high-T mylonitic

  10. Multistage hydrothermal silicification and Fe-Tl-As-Sb-Ge-REE enrichment in the Red Dog Zn-Pb-Ag district, northern Alaska: Geochemistry, origin, and exploration applications

    Science.gov (United States)

    Slack, J.F.; Kelley, K.D.; Anderson, V.M.; Clark, J.L.; Ayuso, R.A.

    2004-01-01

    Geochemical analyses of major, trace, and rare earth elements (REE) in more than 200 samples of variably silicified and altered wall rocks, massive and banded sulfide, silica rock, and sulfide-rich and unmineralized barite were obtained from the Main, Aqqaluk, and Anarraaq deposits in the Red Dog Zn-Pb-Ag district of northern Alaska. Detailed lithogeochemical profiles for two drill cores at Aqqaluk display an antithetic relationship between SiO2/Al2O3 and TiO2/Zr which, together with textural information, suggest preferential silicification of carbonate-bearing sediments. Data for both drill cores also show generally high Tl, Sb, As, and Ge and uniformly positive Eu anomalies (Eu/Eu* > 1.0). Similar high Tl, Sb, As, Ge, and Eu/Eu* values are present in the footwall and shallow hanging wall of Zn-Pb-Ag sulfide intervals at Anarraaq but are not as widely dispersed. Net chemical changes for altered wall rocks in the district, on the basis of average Al-normalized data relative to unaltered black shales of the host Kuna Formation, include large enrichments (>50%) of Fe, Ba, Eu, V, S, Co, Zn, Pb, Tl, As, Sb, and Ge at both Red Dog and Anarraaq, Si at Red Dog, and Sr, U, and Se at Anarraaq. Large depletions (>50%) are evident for Ca at both Red Dog and Anarraaq, for Mg, P, and Y at Red Dog, and for Na at Anarraaq. At both Red Dog and Anarraaq, wall-rock alteration removed calcite and minor dolomite during hydrothermal decarbonation reactions and introduced Si, Eu, and Ge during silicification. Sulfidation reactions deposited Fe, S, Co, Zn, Pb, Tl, As, and Sb; barite mineralization introduced Ba, S, and Sr. Light REE and U were mobilized locally. This alteration and mineralization occurred during Mississippi an hydrothermal events that predated the Middle Jurassic-Cretaceous Brookian orogeny. Early hydrothermal silicification at Red Dog took place prior to or during massive sulfide mineralization, on the basis of the dominantly planar nature of Zn-Pb veins, which suggests

  11. Geochemical Characteristics and Significance of Major Elements, Trace Elements and REE in Mineralized Altered Rocks of Large-Scale Tsagaan Suvarga Cu-Mo Porphyry Deposit in Mongolia

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The alteration types of the large-scale Tsagaan Suvarga Cu-Mo porphyry deposit mostly comprise stockwork silicification, argillization, quartz-sericite alteration, K-silicate alteration, and propylitization.The mineralized and altered zones from hydrothermal metallogenic center to the outside successively are Cu-bearing stockwork silicification zone, Cu-bearing argillized zone, Cu-Mo-bearing quartz-sericite alteration zone, Cu-Mo-bearing K-silicate alteration zone, and propylitization zone.The K-silicate alteration occurred in the early phase, quartz-sericite alteration in the medium phase, and argillization and carbonatization (calcite) in the later phase.Ore-bearing-altered rocks are significantly controlled by the structure and fissure zones of different scales, and NE- and NW-trending fissure zones could probably be the migration pathways of the porphyry hydrothermal system.Results in this study indicated that the less the concentrations of REE, LREE, and HREE and the more the extensive fractionation between LREE and HREE, the closer it is to the center circulatory hydrothermal ore-forming and the more extensive silicification.The exponential relationship between the fractionation of LREE and HREE and the intensity of silicification and K-silicate alteration was found in the Cu-Mo deposit studied.The negative Eu anomaly, normal Eu, positive Eu anomaly and obviously positive Eu anomaly are coincident with the enhancement of Na2O and K2O concentrations gradually, which indicated that Eu anomaly would be significantly controlled by the alkaline metasomatism of the circulatory hydrothermal ore-forming system.Therefore, such characteristics as the positive Eu anomaly, the obvious fractionation between LREE and HREE and their related special alteration lithofacies are suggested to be metallogenic prognostic and exploration indications for Tsagaan Suvarga-style porphyry Cu-Mo deposits in Mongolia and China.

  12. Constraints of REE and trace elements of high-pressure-veins and host rocks in western Tianshan on origin of deep fluids in paleosubduction zones

    Institute of Scientific and Technical Information of China (English)

    HUANG De-zhi; GAO Jun; DAI Ta-gen

    2005-01-01

    The western Tianshan high-pressure(HP) metamorphic belt represents the paleosubduction mélange of paleozoic south Tianshan ocean between the Yili-central Tianshan and Tarim plates. High-pressure veins are extensively developed in this HP belt. Compared with normal mid-ocean ridge basalt(N-MORB), the high-pressure veins and host rocks are enriched in light rare earth elements(LREE) and incompatible elements. But high-pressure veins show a larger variation than host rocks in total REE abundance. On the trace element spidergram, all the samples are enriched in incompatible elements and show strong positive Pb anomaly relative to N-MORB. The array tendency lines of plots of the HP rocks have apparent slopes on diagram of m(Sr) vs m(Sr)/m(Zr), m(Li) vs m(Li)/m(Y) and m(Ce) vs m(Ce)/m(Pb), which indicates that the enrichment in LREE and incompatible elements relative to N-MORB of the HP-metamorphic rocks from western Tianshan is not attributed to magma evolution process of the protolith. High field strength elements, such as Nb, Ta, Ti, Zr and Hf, do not show negative anomaly relative to N-MORB, which is dissimilar to that of island arc basalts. Therefore, the enrichment in LREE and incompatible elements of the HP rocks is not attributed to the enrichment of the source of the protolith. The mass ratios of Rb to Ba, Ce to Pb, Nb to U and Ta to U of high-pressure veins and host rocks are intermediate of mid-ocean ridge basalt or oceanic island basalt and continental crust. The fluids in western Tianshan paleosubduction zones are mixtures of two sources, dehydration or devolatilization of host rocks and of subducted sediments.

  13. Post-magmatic solid solutions of CaCeAl2(Fe3+ 2/3□1/3)[Si2O7][SiO4]O(OH), allanite-(Ce) and REE-bearing epidote in miarolitic pegmatites of Permian Baveno granite (Verbania, central-southern alps, Italy)

    Science.gov (United States)

    Guastoni, Alessandro; Nestola, Fabrizio; Schiazza, Mariangela

    2017-06-01

    CaCeAl2(Fe3+ 2/3□1/3)[Si2O7][SiO4]O(OH), allanite-(Ce) and rare earth element (REE)-bearing epidote occur as globular aggregates and platy prismatic crystals in miarolitic cavities in a niobium, yttrium, fluorine (NYF) granitic pegmatite at Baveno, Verbania, Southern Alps, Italy. These samples were investigated by means of an electron probe micro-analyser (EPMA) and single-crystal X-ray diffraction. Our EPMA results show that the globular aggregates have the highest REE content in the core portion and decreases to REE-bearing epidote towards the rim whereas the prismatic crystals are characterized by marked oscillatory zoning that have the highest REE contents at the rim of the crystal. The unit-cell parameters of "allanites" have an intermediate unit-cell between CaCeAl2(Fe3+ 2/3□1/3)[Si2O7][SiO4]O(OH), allanite-(Ce) and REE-free epidote, because reflect the strong chemical heterogeneity of the samples which form complete solid solutions. Hydrothermal fluids control the activity and precipitation of incompatible elements like high field strength elements (HFSE), Sc and REE by hydrous F-rich fluids below the critical temperature which allow to deposit accessory minerals in the cavities with decreasing temperature. The source of REE and Y are the sheet and REE-silicates like siderophyllite-annite, and gadolinite-(Y) which underwent partial to complete decomposition by the activity of aggressive F-rich hydrothermal fluids.

  14. Geodesic patterns

    KAUST Repository

    Pottmann, Helmut

    2010-07-26

    Geodesic curves in surfaces are not only minimizers of distance, but they are also the curves of zero geodesic (sideways) curvature. It turns out that this property makes patterns of geodesics the basic geometric entity when dealing with the cladding of a freeform surface with wooden panels which do not bend sideways. Likewise a geodesic is the favored shape of timber support elements in freeform architecture, for reasons of manufacturing and statics. Both problem areas are fundamental in freeform architecture, but so far only experimental solutions have been available. This paper provides a systematic treatment and shows how to design geodesic patterns in different ways: The evolution of geodesic curves is good for local studies and simple patterns; the level set formulation can deal with the global layout of multiple patterns of geodesics; finally geodesic vector fields allow us to interactively model geodesic patterns and perform surface segmentation into panelizable parts. © 2010 ACM.

  15. Foam patterns

    Science.gov (United States)

    Chaudhry, Anil R; Dzugan, Robert; Harrington, Richard M; Neece, Faurice D; Singh, Nipendra P; Westendorf, Travis

    2013-11-26

    A method of creating a foam pattern comprises mixing a polyol component and an isocyanate component to form a liquid mixture. The method further comprises placing a temporary core having a shape corresponding to a desired internal feature in a cavity of a mold and inserting the mixture into the cavity of the mold so that the mixture surrounds a portion of the temporary core. The method optionally further comprises using supporting pins made of foam to support the core in the mold cavity, with such pins becoming integral part of the pattern material simplifying subsequent processing. The method further comprises waiting for a predetermined time sufficient for a reaction from the mixture to form a foam pattern structure corresponding to the cavity of the mold, wherein the foam pattern structure encloses a portion of the temporary core and removing the temporary core from the pattern independent of chemical leaching.

  16. Search Patterns

    CERN Document Server

    Morville, Peter

    2010-01-01

    What people are saying about Search Patterns "Search Patterns is a delight to read -- very thoughtful and thought provoking. It's the most comprehensive survey of designing effective search experiences I've seen." --Irene Au, Director of User Experience, Google "I love this book! Thanks to Peter and Jeffery, I now know that search (yes, boring old yucky who cares search) is one of the coolest ways around of looking at the world." --Dan Roam, author, The Back of the Napkin (Portfolio Hardcover) "Search Patterns is a playful guide to the practical concerns of search interface design. It cont

  17. Chladni Pattern

    OpenAIRE

    Xiao, Wence

    2010-01-01

    The report aimed at mathematically describing the Chladni Pattern for a plate based on the equation of motion in two dimensions. It began with deriving the equation of motion of a single point from Newton’s laws, and later derived the equation of motion for the vibration in two dimension, and gave the normal modes through the method of separation of variables. The next was deriving the nodal pattern when the initial conditions and bound- ary conditions were given. At t...

  18. Soils Developed from Different Volcanic Rocks from the Fernando de Noronha Island: Rare-Earth Element Patterns and Isotopic Lead Composition

    Directory of Open Access Journals (Sweden)

    Sonia Maria Barros de Oliveira

    2011-12-01

    Full Text Available This study examines the infl uence of pedogenesis on the distribution of rare earth elements in soils derived fromdifferent rock types and formed under tropical humid climate, as well as the possible contribution of airborne Pb to thesesoils. We studied 5 soil profi les developed from different volcanic rocks cropping out in the Fernando de Noronha island.Results show that in the course of weathering, the soils were enriched in REE. The REE patterns of the soils are similarto those of the parent material, except for a slight HREE enrichment. Lead-isotope data indicate the presence of a nonradiogenicanthropogenic component in the upper horizons of the soil profi les.

  19. Chemical and textural record of REE accessory phases along a well constrained prograde pelitic suite: implications for allanite and monazite petrochronology

    Science.gov (United States)

    Robyr, M.; Goswami-Banerjee, S.; Engi, M.

    2014-12-01

    Because metamorphism comprises a complex sequence of structural changes and chemical reactions that can be extended over several millions of years, metamorphic rocks cannot in general be said to have "an age". As a consequence, interpreting radiometric age data from metamorphic rocks requires first to establish the behavior of the isotopic system used for dating relative to the P-T conditions that a metamorphic rock experienced. As the U-Th-Pb system in monazite and allanite is not easily reset during subsequent temperature increase, allanite and monazite ages are interpreted as reflecting crystallization ages. Consequently, to interpret allanite and monazite crystallization ages, it is crucial to determine the physical conditions of their crystallization. A detailed account of the textural and chemical evolution of allanite and monazite along a well constrained prograde metamorphic suite of detrital sediments of the Greater Himalaya of Zanskar reveals that: (1) allanite is the stable REE accessory phase in the biotite and garnet zone and (2) at the staurolite-in isograd, allanite disappears abruptly from the metamorphic assemblage, simultaneously with the occurrence of the first metamorphic monazite. The finding of both monazite and allanite as inclusion in staurolite indicates that the breakdown of allanite and the formation of monazite occurred during staurolite crystallization. The preservation of allanite and monazite inclusions in garnet core and rim respectively allows to accurately identify the P-T conditions of the formation of the first metamorphic monazite. Thermobarometry indicates that, in both cases, monazite crystallization occurred at 600 °C. The fact that the substitution of allanite by monazite occurs spatially close, i.e. at similar P-T conditions, in all types of rocks whether they are Al-rich metapelites or more psammitic metasediments indicates that major silicate phases like staurolite or garnet do not play a significant role in the monazite

  20. Biodegradation of the french reference nuclear glass SON 68 by Acidithiobacillus thiooxidans : protective effect of the biofilm,U and REE retention

    Science.gov (United States)

    Bachelet, M.; Crovisier, J.; Stille, P.; Boutin, R.; Vuilleumier, S.; Geoffroy, V.

    2008-12-01

    Although underground nuclear waste repositories are not expected to be favourable places for microbial activity, one should not exclude localized action of extremophilic bacteria on some materials involved in the storage concept. Among endogenous or accidentally introduced acidophiles, some are susceptible to lead to a locally drastic decreased in pH with potential consequences on materials corrosion. Experiments were performed with Acidithiobacillus thiooxidans on 100-125 μm french reference nuclear glass SON68 grains in a mineral medium under static conditions during 60 days at 25°C. Growth medium was periodically renewed and analyzed by ICP-AES and ICP-MS spectrometry for both major, traces and ultra-traces elements. Biofilm formation was evidenced by confocal laser microscopy, staining DNA with ethidium bromide and exopolysaccharides with calcofluor white. Biofilm thickness around material grains exceeded 20 μm under the chosen experimental conditions. It can be noticed that while numerous studies on biofilm formation upon interaction between Acidithiobacillus ferrooxidans and materials can be found in the literature, evidence for biofilm formation is still scarce for the case of the acidophilic bacterium A. thiooxidans. Presence of biofilm is a key parameter for material alteration at the solid/solution interface in biotic systems. Indeed, various constitutive elements of materials trapped in the polyanionic polymer of biofilm may also influence the alteration process. In particular, biofilm may reduce the alteration rate of materials by forming a protective barrier at their surface (Aouad et al., 2008). In this study, glass alteration rates, determined using strontium, molybdenum and caesium as tracers, showed that the biofilm has a protective effect against glass alteration. U and REE are efficiently trapped in the biogenic compartment of the system (exopolysaccharides (EPS) + bacterial cells). Biofilm analysis are in progress to determine whether these

  1. Pattern Formation

    Science.gov (United States)

    Hoyle, Rebecca

    2006-03-01

    From the stripes of a zebra and the spots on a leopard's back to the ripples on a sandy beach or desert dune, regular patterns arise everywhere in nature. The appearance and evolution of these phenomena has been a focus of recent research activity across several disciplines. This book provides an introduction to the range of mathematical theory and methods used to analyse and explain these often intricate and beautiful patterns. Bringing together several different approaches, from group theoretic methods to envelope equations and theory of patterns in large-aspect ratio-systems, the book also provides insight behind the selection of one pattern over another. Suitable as an upper-undergraduate textbook for mathematics students or as a fascinating, engaging, and fully illustrated resource for readers in physics and biology, Rebecca Hoyle's book, using a non-partisan approach, unifies a range of techniques used by active researchers in this growing field. Accessible description of the mathematical theory behind fascinating pattern formation in areas such as biology, physics and materials science Collects recent research for the first time in an upper level textbook Features a number of exercises - with solutions online - and worked examples

  2. Study of Character and Trace of REE in Xiangshan Uranium Ore Field%相山铀矿田稀土元素地球化学特征及示踪研究

    Institute of Scientific and Technical Information of China (English)

    廖宇华

    2000-01-01

    Xiangshan Uranium ore fieled is a famous Volcanic type hydrothermal uranium ore field. The author studysgeochemical character of samples of REE of 4 reprentive uranium ores,of which are ore-host rock, uranium mine andpitchblende. This paper discusses material resource of rock-forming ore-forming, unveilings REE of uranium ore andmineralization of uranium of two difference geochemical types of mine,bring out relation of direct ratio, especialy urani-um and heavy REE in rich mine ore, which come from inner oviginal fluid and bring ont Co-precipitation. The strongeruranium-hydrothermal differntiation evolution is, the richer minerarli zation of uranium is.%相山铀矿田是我国著名的火山岩型热液铀矿田。作者对矿田4个有代表性的铀矿床的赋矿主岩、铀矿石、沥青铀矿样品稀土元素地球化学特征进行了研究,探讨了其成岩、成矿的物质来源,揭示了两种不同地球化学类型铀矿床的稀土元素与铀矿化呈正消长关系,尤其是富矿床中铀与重稀土元素,主要来自深部原生流体,并呈现出共沉淀的特点,含铀热液分异演化愈强,则铀矿化愈富。

  3. Description and critical environmental evaluation of the REE refining plant LAMP near Kuantan/Malaysia. Radiological and non-radiological environmental consequences of the plant's operation and its wastes

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, Gerhard

    2013-01-25

    The description of the critical environmental evaluation of the REE refining plant LAMP near Kuantan/Malaysia covers the radiological and non-radiological consequences of the plant operation and its waste. The Australian company Lynas plans to import ore concentrate from Australia to Malaysia and to process the concentrate in the plant LAMP in Kuantan, Malaysia. The authors have analyzed the emissions of radon over the stack, the emissions of sulfuric acid and dust over the stack, the hazards and their control in the production processes and the wastes from the production process with respect to the radiological and non-radiological toxicity.

  4. The use of decision tree induction and artificial neural networks for recognizing the geochemical distribution patterns of LREE in the Choghart deposit, Central Iran

    Science.gov (United States)

    Zaremotlagh, S.; Hezarkhani, A.

    2017-04-01

    Some evidences of rare earth elements (REE) concentrations are found in iron oxide-apatite (IOA) deposits which are located in Central Iranian microcontinent. There are many unsolved problems about the origin and metallogenesis of IOA deposits in this district. Although it is considered that felsic magmatism and mineralization were simultaneous in the district, interaction of multi-stage hydrothermal-magmatic processes within the Early Cambrian volcano-sedimentary sequence probably caused some epigenetic mineralizations. Secondary geological processes (e.g., multi-stage mineralization, alteration, and weathering) have affected on variations of major elements and possible redistribution of REE in IOA deposits. Hence, the geochemical behaviors and distribution patterns of REE are expected to be complicated in different zones of these deposits. The aim of this paper is recognizing LREE distribution patterns based on whole-rock chemical compositions and automatic discovery of their geochemical rules. For this purpose, the pattern recognition techniques including decision tree and neural network were applied on a high-dimensional geochemical dataset from Choghart IOA deposit. Because some data features were irrelevant or redundant in recognizing the distribution patterns of each LREE, a greedy attribute subset selection technique was employed to select the best subset of predictors used in classification tasks. The decision trees (CART algorithm) were pruned optimally to more accurately categorize independent test data than unpruned ones. The most effective classification rules were extracted from the pruned tree to describe the meaningful relationships between the predictors and different concentrations of LREE. A feed-forward artificial neural network was also applied to reliably predict the influence of various rock compositions on the spatial distribution patterns of LREE with a better performance than the decision tree induction. The findings of this study could be

  5. Rare earth element patterns of the Central Indian Basin sediments related to their lithology

    Digital Repository Service at National Institute of Oceanography (India)

    Nath, B.N.; Roelandts, I.; Sudhakar, M.; Pluger, W.L.

    Rare earth element (REE) concentration have been determined in terrigenous, siliceous (nodule barren and nodule bearing), calcareous, and red clay from the Central Indian Basin. The bulk distribution of REE, and in particular the relative cerium...

  6. Fractionation of Rare Earth Elements in Plants Ⅰ. Fractionation Patterns and Their Forming Mechanisms in Different Organs of Triticum Aestivum

    Institute of Scientific and Technical Information of China (English)

    Liang Tao; Ding Shiming; Zhang Chaosheng; Zhang Zili; Yan Juncai; Li Haitao

    2005-01-01

    Fractionations of rare earth elements (REEs) and the forming mechanisms in plants were studied using Triticum aestivum as plant material with application of exogenous REEs and hydroponic culture. REEs were significantly fractionated in different parts of Triticum aestivum. M-type tetrad effect could be observed in both root and shoot of Triticum aestivum, which might result from the different abilities of REEs to form phosphate precipitation. Middle REEs (MREEs), light REEs (LREEs) and heavy REEs (HREEs) were enriched in root, stem and leaf of Triticum aestivum, respectively. REE speciation calculations using VMINTEQ program show REEs in simulated xylem solution mainly exist as REE-EDTA- and RE3+, but only HREEs are enriched in REE-EDTA-, while LREEs are enriched in the other REE species. It is suggested that the fractionation between LREEs and HREEs might be caused by the uptake of REE-EDTA- in Triticum aestivum leaves, but might result from the uptake of the other REE species in their stems.

  7. Proof patterns

    CERN Document Server

    Joshi, Mark

    2015-01-01

    This innovative textbook introduces a new pattern-based approach to learning proof methods in the mathematical sciences. Readers will discover techniques that will enable them to learn new proofs across different areas of pure mathematics with ease. The patterns in proofs from diverse fields such as algebra, analysis, topology and number theory are explored. Specific topics examined include game theory, combinatorics, and Euclidean geometry, enabling a broad familiarity. The author, an experienced lecturer and researcher renowned for his innovative view and intuitive style, illuminates a wide range of techniques and examples from duplicating the cube to triangulating polygons to the infinitude of primes to the fundamental theorem of algebra. Intended as a companion for undergraduate students, this text is an essential addition to every aspiring mathematician’s toolkit.

  8. Pattern classification

    CERN Document Server

    Duda, Richard O; Stork, David G

    2001-01-01

    The first edition, published in 1973, has become a classic reference in the field. Now with the second edition, readers will find information on key new topics such as neural networks and statistical pattern recognition, the theory of machine learning, and the theory of invariances. Also included are worked examples, comparisons between different methods, extensive graphics, expanded exercises and computer project topics. An Instructor's Manual presenting detailed solutions to all the problems in the book is available from the Wiley editorial department.

  9. Contrasting geochemical and Sm-Nd isotopic compositions of Archean metasediments from the Kongling high-grade terrain of the Yangtze craton: Evidence for cratonic evolution and redistribution of REE during crustal anatexis

    Science.gov (United States)

    Gao, Shan; Ling, Wenli; Qiu, Yumin; Lian, Zhou; Hartmann, Gerald; Simon, Klaus

    1999-07-01

    Twenty-three clastic metasediments from the Kongling high-grade terrain of the Yangtze craton, South China were analyzed for major, trace and rare earth elements and Sm-Nd isotopic ratios. Associated dioritic-tonalitic-trondhjemitic (DTT) and granitic gneisses as well as amphibolites were also analyzed in order to constrain provenance. The results show that the clastic metasediments can be classified into 3 distinct groups in terms of mineralogical, geochemical and Sm-Nd isotopic compositions. Group A is characterized by having no to slight negative Eu anomalies (Eu/Eu∗ = 0.82-1.07), being high in Cr (191-396 ppm) and Ni (68-137 ppm), and low in Th (3.3-7.8 ppm) and REEREE = 99-156 ppm). These characteristics are similar to those of metasediments from Archean greenstone belts. In addition, the Group A metasediments have the value of the Chemical Index of Alteration (CIW) close to felsic gneisses. Their Sm-Nd isotopic, REE and trace element compositions can be interpreted by mixtures of the DTT gneisses and amphibolites. Dating of detrital zircons from 2 Group A samples by SHRIMP reveals a major concordant age group of 2.87-3.0 Ga, which is identical to the age of the trondhjemitic gneiss. These results strongly suggest that Group A was principally the first-cycle erosion product of the local Kongling DTT gneiss and amphibolite. Moreover, the higher than amphibolite Cr content and slight Eu depletion exhibited by some samples from this group infer that ultramafic rocks like komatiite and granite of probably 3.0-3.3 Ga in age also played a role. Group B is characterized by the presence of graphite and shows a more evolved composition similar to post-Archean shales with a prominent negative Eu anomaly (Eu/Eu∗ = 0.48-0.77) and high CIW. On paired Cr/Th vs La/Co and Co/Th plots, Group B samples conform to a two-end member mixing line of the Kongling granitic gneiss and amphibolite. However, data on Nd model age and CIW suggest that the granite component should

  10. A Nd- and O-isotope study of the REE-rich peralkaline Strange Lake granite: implications for Mesoproterozoic A-type magmatism in the Core Zone (NE-Canada)

    Science.gov (United States)

    Siegel, Karin; Williams-Jones, Anthony E.; Stevenson, Ross

    2017-07-01

    It is well established that A-type granites enriched in high field strength elements, such as Zr, Nb and the REE, form in anorogenic tectonic settings. The sources of these elements and the processes controlling their unusual enrichment, however, are still debated. They are addressed here using neodymium and oxygen isotope analyses of samples from the 1.24 Ga Strange Lake pluton in the Paleoproterozoic Core Zone of Québec-Labrador, an A-type granitic body characterized by hyper-enrichment in the REE, Zr, and Nb. Age-corrected ɛNd values for bulk rock samples and sodic amphiboles (mainly arfvedsonite) from the pluton range from -0.6 to -5.7, and -0.3 to -5.3, respectively. The ɛNd values for the Napeu Kainiut quartz monzonite, which hosts the pluton, range from -4.8 to -8.1. The 147Sm/144Nd ratios of the suite and the host quartz monzonite range from 0.0967 to 0.1659, large variations that can be explained by in situ fractionation of early LREE-minerals (Strange Lake), and late hydrothermal HREE remobilization. Oxygen isotope analyses of quartz of both Strange Lake and the host yielded δ18O values between +8.2 and +9.1, which are considerably higher than the mantle value of 5.7 ± 0.2‰. Bulk rock oxygen isotope analyses of biotite-gneisses in the vicinity of the Strange Lake pluton yielded δ18O values of 6.3, 8.6 and 9.6‰. The negative ɛNd values and positive δ18O values of the Strange Lake and Napeu Kainiut samples indicate that both magmas experienced considerable crustal contamination. The extent of this contamination was estimated, assuming that the contaminants were sedimentary-derived rocks from the underlying Archean Mistinibi (para-) gneiss complex, which is characterized by low ɛNd and high δ18O values. Mixing of 5-15% of a gneiss, having an ɛNd value of -15 and a δ18O value of +11, with a moderately enriched mantle source (ɛNd = +0.9, δ18O = +6.3) would produce values similar to those obtained for the Strange Lake granites. Based on

  11. Java enterprise design patterns patterns in Java

    CERN Document Server

    Grand, Mark

    2002-01-01

    A how-to guide for Java programmers who want to use design patterns when developing real-world enterprise applicationsThis practical book explores the subject of design patterns, or patterns that occur in the design phase of a project''s life cycle. With an emphasis on Java for the enterprise, Mark Grand guides Java programmers on how to apply traditional and new patterns when designing a large enterprise application. The author clearly explains how existing patterns work with the new enterprise design patterns and demonstrates through case studies how to use design patterns in the real world.

  12. 江西相山火山-侵入杂岩及其包体稀土元素地球化学%REE-Geochemistry of Mesozoic Volcanic-Intrusive Complex and Dark Inclusions in Xiangshan District,Jiangxi Pronvince

    Institute of Scientific and Technical Information of China (English)

    段芸; 赵连泽; 范洪海; 王德滋

    2001-01-01

    本文综合性地报道了江西相山中生代中、酸性火山 -侵入杂岩的稀土元素地球化 学研究,以探讨基底变质岩、火山岩、次火山岩及闪长质包体之间的成因联系和差异性。认为此套火山-侵入杂岩具同源演化关系,推测它们均来源于前震旦系结晶基底,成因上属 于陆壳重熔型。这与前人对此研究的主流观点是一致的,同时更具完整性和系统性。%The dark-coloured enclaves were found in subvocanic dike for the first time in the Xiangshan district,Jiangxi Province,which provi des anew information for studying Mesozoic vocanic-intrusiv e complex in this region.This kind of enclaves exs it in small amounts,with chilled margin,back veins,and other obvious quenchi ng characteristics.Petrologically they are mainly dioritoids.   We collected 14 samples,including the basemental rocks,vocanic rocks,subvocan ic rocks and dark enclaves,and made detailed REE analyses on them.Combining wit h the previous study,we tried to explain the genetic relationsh ip and difference between them ina more integrated and systematic way.The data and diagrams demonstrate that: 1) as a whole,the magmas which formed various v olcanic rocks with slight to intermediate fractionation degree of REE and stron g europium negative anomalies,were differentiated and evolved in the same magmatic reservoir.The latter was originated f rom the continental crust; 2) products of the bicyclic volcanic act ivity,rhyodacite and porphyroclast lava,represent double emptying of magma res e rvoir; 3) REE data of dioritic enclaves don't show strong europium negative an omalies.Conseguently we concluded that the the magma of these enclaves was d er ived from a deeper level,and could be a mixture of lower crust and enriched mantle with a higher mixing proportion.   Furthermore,Pb,Sr,Nd isotope data also provided similar information.εNd(t) of volcanics and subvocanics are -8.8 and -11.2,respectively

  13. Fluid sources and metallogenesis in the Blackbird Co-Cu-Au-Bi-Y-REE district, Idaho, U.S.A.: Insights from major-element and boron isotopic compositions of tourmaline

    Science.gov (United States)

    Trumbull, R.B.; Slack, J.F.; Krienitz, M.-S.; Belkin, H.E.; Wiedenbeck, M.

    2011-01-01

    Tourmaline is a widespread mineral in the Mesoproterozoic Blackbird Co-Cu-Au-Bi-Y-REE district, Idaho, where it occurs in both mineralized zones and wallrocks. We report here major-element and B-isotope compositions of tourmaline from stratabound sulfide deposits and their metasedimentary wallrocks, from mineralized and barren pipes of tourmaline breccia, from late barren quartz veins, and from Mesoproterozoic granite. The tourmalines are aluminous, intermediate in the schorl-dravite series, with Fe/(Fe + Mg) values of 0.30 to 0.85, and 10 to 50% X-site vacancies. Compositional zoning is prominent only in tourmaline from breccias and quartz veins; crystal rims are enriched in Mg, Ca and Ti, and depleted in Fe and Al relative to cores. The chemical composition of tourmaline does not correlate with the presence or absence of mineralization. The ??11B values fall into two groups. Isotopically light tourmaline (-21.7 to-7.6%o) occurs in unmineralized samples from wallrocks, late quartz veins and Mesoproterozoic granite, whereas heavy tourmaline (-6.9 to +3.2%o) is spatially associated with mineralization (stratabound and breccia-hosted), and is also found in barren breccia. At an inferred temperature of 300??C, boron in the hydrothermal fluid associated with mineralization had ??11B values of-3 to +7%o. The high end of this range indicates a marine source of the boron. A likely scenario involves leaching of boron principally from marine carbonate beds or B-bearing evaporites in Mesoproterozoic strata of the region. The ??11B values of the isotopically light tourmaline in the sulfide deposits are attributed to recrystallization during Cretaceous metamorphism, superimposed on a light boron component derived from footwall siliciclastic sediments (e.g., marine clays) during Mesoproterozoic mineralization, and possibly a minor component of light boron from a magmatic-hydrothermal fluid. The metal association of Bi-Be-Y-REE in the Blackbird ores suggests some magmatic input

  14. In situ Sr isotope analysis of apatite by LA-MC-ICPMS: constraints on the evolution of ore fluids of the Yinachang Fe-Cu-REE deposit, Southwest China

    Science.gov (United States)

    Zhao, Xin-Fu; Zhou, Mei-Fu; Gao, Jian-Feng; Li, Xiao-Chun; Li, Jian-Wei

    2015-10-01

    Apatite is a ubiquitous accessory mineral in a variety of rocks and hydrothermal ores. Strontium isotopes of apatite are well known to retain petrogenetic information and have been widely used to investigate the origin of igneous rocks, but such attempts have rarely been made to constrain ore-forming processes of hydrothermal systems. We here report in situ LA-MC-ICPMS Sr isotope data of apatite from the ~1660-Ma Yinachang Fe-Cu-REE deposit, Southwest China. The formation of this deposit was coeval to the emplacement of regionally distributed doleritic intrusions within a continental-rift setting. The deposit has a paragenetic sequence consisting of sodic alteration (stage I), magnetite mineralization (stage II), Cu sulfide and REE mineralization (stage III), and final barren calcite veining (stage IV). The stage II and III assemblages contain abundant apatite, allowing to investigate the temporal evolution of the Sr isotopic composition of the ore fluids. Apatite of stage II (Apt II) is associated with fluorite, magnetite, and siderite, whereas apatite from stage III (Apt III) occurs intimately intergrown with ankerite and Cu sulfides. Apt II has 87Sr/86Sr ratios varying from 0.70377 to 0.71074, broadly compatible with the coeval doleritic intrusions (0.70592 to 0.70692), indicating that ore-forming fluids responsible for stage II magnetite mineralization were largely equilibrated with mantle-derived mafic rocks. In contrast, Apt III has distinctly higher 87Sr/86Sr ratios from 0.71021 to 0.72114, which are interpreted to reflect external radiogenic Sr, likely derived from the Paleoproterozoic strata. Some Apt III crystals have undergone extensive metasomatism indicated by abundant monazite inclusions. The metasomatized apatite has much higher 87Sr/86Sr ratios up to 0.73721, which is consistent with bulk-rock Rb-Sr isotope analyses of Cu ores with 87Sr/86Sri from 0.71906 to 0.74632. The elevated 87Sr/86Sr values of metasomatized apatite and bulk Cu ores indicate

  15. Privacy transparency patterns

    NARCIS (Netherlands)

    Siljee B.I.J.

    2015-01-01

    This paper describes two privacy patterns for creating privacy transparency: the Personal Data Table pattern and the Privacy Policy Icons pattern, as well as a full overview of privacy transparency patterns. It is a first step in creating a full set of privacy design patterns, which will aid

  16. Privacy transparency patterns

    NARCIS (Netherlands)

    Siljee B.I.J.

    2015-01-01

    This paper describes two privacy patterns for creating privacy transparency: the Personal Data Table pattern and the Privacy Policy Icons pattern, as well as a full overview of privacy transparency patterns. It is a first step in creating a full set of privacy design patterns, which will aid softwar

  17. Design Verifikation Patterns

    DEFF Research Database (Denmark)

    Knudsen, John; Ravn, Anders Peter; Skou, Arne

    2007-01-01

    Design Verification Patterns are formal specifications that define the semantics of design patterns. For each design pattern, the corresponding verification pattern give a set of proof obligations. They must be discharged for a correct implementation of the pattern. Additionally there is a set...... of properties that may be used in the design and verification of applications that employ the pattern. The concept is illustrated by examples from general software engineering and more specialised properties for embedded software....

  18. Design Verifikation Patterns

    DEFF Research Database (Denmark)

    Knudsen, John; Ravn, Anders Peter; Skou, Arne

    2007-01-01

    Design Verification Patterns are formal specifications that define the semantics of design patterns. For each design pattern, the corresponding verification pattern give a set of proof obligations. They must be discharged for a correct implementation of the pattern. Additionally there is a set of...... of properties that may be used in the design and verification of applications that employ the pattern. The concept is illustrated by examples from general software engineering and more specialised properties for embedded software.......Design Verification Patterns are formal specifications that define the semantics of design patterns. For each design pattern, the corresponding verification pattern give a set of proof obligations. They must be discharged for a correct implementation of the pattern. Additionally there is a set...

  19. Derivative Sign Patterns

    Science.gov (United States)

    Clark, Jeffrey

    2011-01-01

    Analysis of the patterns of signs of infinitely differentiable real functions shows that only four patterns are possible if the function is required to exhibit the pattern at all points in its domain and that domain is the set of all real numbers. On the other hand all patterns are possible if the domain is a bounded open interval.

  20. Patterns for agility

    NARCIS (Netherlands)

    Iacob, M.E.; Lankhorst, M.M.; Schrier, A.; Lankhorst, M.

    2012-01-01

    The use of patterns is an important practice in the agile software development community. There are many sources for patterns. In this chapter, we will examine several pattern collections and explore their potential contribution to system agility. We illustrate our pattern approach by a detailed exa

  1. Derivative Sign Patterns

    Science.gov (United States)

    Clark, Jeffrey

    2011-01-01

    Analysis of the patterns of signs of infinitely differentiable real functions shows that only four patterns are possible if the function is required to exhibit the pattern at all points in its domain and that domain is the set of all real numbers. On the other hand all patterns are possible if the domain is a bounded open interval.

  2. Polytypic pattern matching

    NARCIS (Netherlands)

    Jeuring, J.T.

    2007-01-01

    The pattern matching problem can be informally specified as follows: given a pattern and a text, find all occurrences of the pattern in the text. The pattern and the text may both be lists, or they may both be trees, or they may both be multi-dimensional arrays, etc. This paper describes a general p

  3. Patterns that matter

    NARCIS (Netherlands)

    van Leeuwen, M.

    2010-01-01

    Pattern mining is one of the best-known concepts in Data Mining. A big problem in pattern mining is that humongous amounts of patterns can be mined even from small datasets. This makes it hard for domain experts to discover knowledge using pattern mining, for example in the field of Bioinformatics.

  4. PO3-4和柠檬酸对稀土元素在小麦体内积累和分异的影响%Influence of PO34- and Citrate on REE Accumulation and Fractionation in Wheat

    Institute of Scientific and Technical Information of China (English)

    闫军才; 梁涛; 张自立; 丁士明

    2005-01-01

    基于营养液培养,添加外源稀土和ICP-MS分析技术,研究了无机配体PO43-(Pi)及有机配体柠檬酸(Cit)对小麦器官中稀土元素积累和分异的影响.结果表明,不同Pi水平对小麦根中的稀土总含量(∑REE)影响较小,但显著降低叶中∑REE含量;而不同Cit水平对小麦根、叶中∑REE含量都有明显降低作用.对照植物(无Pi、Cit添加)中,稀土元素在小麦根中具有中稀土(MREE)富集及M-型四重效应分布特征,叶中有重稀土(HREE)富集及W-型四重效应分布特征.不同Pi处理对四重效应无明显作用,但进一步加强HREE在小麦叶片中的富集.添加柠檬酸使对照植物根和叶中的分异有逐渐减弱的趋势,在高浓度处理时(Cit≥150μmol·L-1),小麦根和叶中出现轻稀土(LREE)富集.

  5. Pattern evaporation process

    Directory of Open Access Journals (Sweden)

    Z. Żółkiewicz

    2007-04-01

    Full Text Available The paper discusses the process of thermal evaporation of a foundry pattern. At several research-development centres, studies have been carried out to examine the physico-chemical phenomena that take place in foundry mould filled with polystyrene pattern when it is poured with molten metal. In the technique of evaporative patterns, the process of mould filling with molten metal (the said mould holding inside a polystyrene pattern is interrelated with the process of thermal decomposition of this pattern. The transformation of an evaporative pattern (e.g. made from foamed polystyrene from the solid into liquid and then gaseous state occurs as a result of the thermal effect that the liquid metal exerts onto this pattern. Consequently, at the liquid metal-pattern-mould phase boundary some physico-chemical phenomena take place, which until now have not been fully explained. When the pattern is evaporating, some solid and gaseous products are evolved, e.g. CO, CO2, H2, N2, and hydrocarbons, e.g. styrene, toluene, ethane, methane, benzene [16, 23]. The process of polystyrene pattern evaporation in foundry mould under the effect of molten metal is of a very complex nature and depends on many different factors, still not fully investigated. The kinetics of pattern evaporation is also affected by the technological properties of foundry mould, e.g. permeability, thermophysical properties, parameters of the gating system, temperature of pouring, properties of pattern material, and the size of pattern-liquid metal contact surface.

  6. Male pattern baldness

    Science.gov (United States)

    Alopecia in men; Baldness - male; Hair loss in men; Androgenetic alopecia ... Male pattern baldness is related to your genes and male sex hormones. It usually follows a pattern of receding hairline and ...

  7. Male pattern baldness (image)

    Science.gov (United States)

    Male pattern baldness is a sex-linked characteristic that is passed from mother to child. A man can more accurately predict his chances of developing male pattern baldness by observing his mother's father than by looking ...

  8. Four integration patterns

    DEFF Research Database (Denmark)

    Bygstad, Bendik; Nielsen, Peter Axel; Munkvold, Bjørn Erik

    2010-01-01

    . Expanding the perspective of traditional project management research, we draw extensively on central insights from IS research. Building on socio-technical IS research and Software Engineering research we suggest four generic patterns of integration: Big Bang, Stakeholder Integration, Technical Integration...... and Socio-Technical Integration. We analyze and describe the advantages and disadvantages of each pattern. The four patterns are ideal types. To explore the forces and challenges in these patterns three longitudinal case studies were conducted. In particular we investigate the management challenges for each...... pattern. We find that the patterns are context sensitive, and describe the different contexts where the patterns are applicable. For IS project management the four integration patterns is a contribution to the management of integration risks, extending the vocabulary for assessing and mitigating...

  9. Innis Ree Lodge, Ballyleague, Lanesborough, Roscommon.

    LENUS (Irish Health Repository)

    McDonald, Fiona B

    2016-03-01

    Intermittent hypoxia is a feature of apnea of prematurity (AOP), chronic lung disease, and sleep apnea. Despite the clinical relevance, the long-term effects of hypoxic exposure in early life on respiratory control are not well defined. We recently reported that exposure to chronic intermittent hypoxia (CIH) during postnatal development (pCIH) causes upper airway muscle weakness in both sexes, which persists for several weeks. We sought to examine if there are persistent sex-dependent effects of pCIH on respiratory muscle function into adulthood and\\/or increased susceptibility to re-exposure to CIH in adulthood in animals previously exposed to CIH during postnatal development. We hypothesized that pCIH would cause long-lasting muscle impairment and increased susceptibility to subsequent hypoxia. Within 24 h of delivery, pups and their respective dams were exposed to CIH: 90 s of hypoxia reaching 5% O2 at nadir; once every 5 min, 8 h per day for 3 weeks. Sham groups were exposed to normoxia in parallel. Three groups were studied: sham; pCIH; and pCIH combined with adult CIH (p+aCIH), where a subset of the pCIH-exposed pups were re-exposed to the same CIH paradigm beginning at 13 weeks. Following gas exposures, sternohyoid and diaphragm muscle isometric contractile and endurance properties were examined ex vivo. There was no apparent lasting effect of pCIH on respiratory muscle function in adults. However, in both males and females, re-exposure to CIH in adulthood in pCIH-exposed animals caused sternohyoid (but not diaphragm) weakness. Exposure to this paradigm of CIH in adulthood alone had no effect on muscle function. Persistent susceptibility in pCIH-exposed airway dilator muscle to subsequent hypoxic insult may have implications for the control of airway patency in adult humans exposed to intermittent hypoxic stress during early life.

  10. Pattern polynomial graphs

    CERN Document Server

    Reddy, A Satyanarayana

    2011-01-01

    A graph $X$ is said to be a pattern polynomial graph if its adjacency algebra is a coherent algebra. In this study we will find a necessary and sufficient condition for a graph to be a pattern polynomial graph. Some of the properties of the graphs which are polynomials in the pattern polynomial graph have been studied. We also identify known graph classes which are pattern polynomial graphs.

  11. Mathematical Pattern Hunters

    Science.gov (United States)

    Whitin, Phyllis; Whitin, David J.

    2011-01-01

    The habit of looking for patterns, the skills to find them, and the expectation that patterns have explanations is an essential mathematical habit of mind for young children (Goldenberg, Shteingold, & Feurzeig 2003, 23). Work with patterns leads to the ability to form generalizations, the bedrock of algebraic thinking, and teachers must nurture…

  12. Applied MVC Patterns. A pattern language

    OpenAIRE

    Alpaev, Sergey

    2006-01-01

    How to get advantages of MVC model without making applications unnecessarily complex? The full-featured MVC implementation is on the top end of ladder of complexity. The other end is meant for simple cases that do not call for such complex designs, however still in need of the advantages of MVC patterns, such as ability to change the look-and-feel. This paper presents patterns of MVC implementation that help to benefit from the paradigm and keep the right balance between flexibility and imple...

  13. Ramadan major dietary patterns.

    Science.gov (United States)

    Shadman, Zhaleh; Poorsoltan, Nooshin; Akhoundan, Mahdieh; Larijani, Bagher; Soleymanzadeh, Mozhdeh; Akhgar Zhand, Camelia; Seyed Rohani, Zahra Alsadat; Khoshniat Nikoo, Mohsen

    2014-09-01

    There has been no data on population based dietary patterns during the Ramadan fasting month. The purpose of this study was to detect Ramadan major dietary patterns among those who fast in Tehran. This cross-sectional study included 600 subjects, aged 18-65 with body mass index (BMI) of 18.5-40, who had decided to fast during Ramadan. Anthropometric measurements, usual physical activity level and educational status were collected two weeks before Ramadan. Information on Ramadan dietary intakes was obtained using a food frequency questionnaire and factor analysis was used to identify major dietary patterns. We identified four major dietary patterns: 1) Western-like pattern; high in fast foods, salty snacks, nuts, potato, fish, poultry, chocolates, juices; 2) high cholesterol and high sweet junk food pattern; high in pickles, sweets and condiments, butter and cream, canned fish, visceral meats and eggs; 3) Mediterranean-like pattern; high in vegetables, olive oil, dates, dairy, dried fruits, fruits, red meats, tea and coffee and 4) Ramadan-style pattern; large consumption of Halim, soups, porridges, legumes and whole grains, soft drinks, Zoolbia and Bamieh. Age was positively and inversely associated with Mediterranean-like (P = 0.003; r = 0.17) and Ramadan style (P = 0.1; r = -0.13) dietary pattern, respectively. Pre-Ramadan physical activity level was associated with a Mediterranean-like dietary pattern (P < 0.0001; r = 0.20). This study showed a Ramadan-specific dietary pattern has unique characteristics, which has not yet been identified as a model of dietary pattern. Also, among identified dietary patterns, Mediterranean-like was the healthiest.

  14. Pattern recognition & machine learning

    CERN Document Server

    Anzai, Y

    1992-01-01

    This is the first text to provide a unified and self-contained introduction to visual pattern recognition and machine learning. It is useful as a general introduction to artifical intelligence and knowledge engineering, and no previous knowledge of pattern recognition or machine learning is necessary. Basic for various pattern recognition and machine learning methods. Translated from Japanese, the book also features chapter exercises, keywords, and summaries.

  15. Learning Python design patterns

    CERN Document Server

    Zlobin, Gennadiy

    2013-01-01

    This book takes a tutorial-based and user-friendly approach to covering Python design patterns. Its concise presentation means that in a short space of time, you will get a good introduction to various design patterns.If you are an intermediate level Python user, this book is for you. Prior knowledge of Python programming is essential. Some knowledge of UML is also required to understand the UML diagrams which are used to describe some design patterns.

  16. Professional ASPNET Design Patterns

    CERN Document Server

    Millett, Scott

    2010-01-01

    Professional ASP.NET Design Patterns will show you how to implement design patterns in real ASP.NET applications by introducing you to the basic OOP skills needed to understand and interpret design patterns. A sample application used throughout the book is an enterprise level ASP.NET website with multi-tiered, SOA design techniques that can be applied to your future ASP.NET projects. Read about each design pattern in detail, including how to interpret the UML design, how to implement it in ASP.NET, its importance for ASP.NET development, and how it's integrated into the final project.

  17. Patterns - "A crime solver"

    Directory of Open Access Journals (Sweden)

    A Nagasupriya

    2011-01-01

    Full Text Available Objective: This study is intended to analyze the predominant pattern of lip and finger prints in males and females and to correlate lip print and finger print for gender identity. Materials and Methods: The study sample comprised of 200 students of Vishnu Dental College, Bhimavaram, Andhra Pradesh, 100 males and 100 females aged between 18 to 27 years. Brown/pink colored lip stick was applied on the lips and the subject was asked to spread it uniformly over the lips. Lip prints were traced in the normal rest position of the lips with the help of cellophane tape. The imprint of the left thumb was taken on a white chart sheet and visualized using magnifying lens. While three main types of finger prints are identified, the classification of lip prints is simplified into branched, reticular, and vertical types. Association between lip prints and finger prints was statistically tested using Chi-square test. Results: This study showed that lip and finger patterns did not reveal statistically significant results within the gender. The correlation between lip and finger patterns for gender identification, was statistically significant. In males, branched type of lip pattern associated with arch, loop, and whorl type of finger pattern was most significant. In females, vertical lip pattern associated with arch finger pattern and reticular lip pattern associated with whorl finger patterns were most significant. Conclusion: We conclude that a correlative study between the lip print and finger print will be very useful in forensic science for gender identification.

  18. Wavelengths of Bioconvection Patterns

    DEFF Research Database (Denmark)

    Bees, Martin Alan; Hill, N.A.

    1998-01-01

    Bioconvection occurs as the result of the collective behaviour of many micro-organisms swimming in a fluid and is realised as patterns similar to those of thermal convection which occur when a layer of water is heated from below. A methodology is developed to record the bioconvection patterns...

  19. Is It a Pattern?

    Science.gov (United States)

    McGarvey, Lynn M.

    2013-01-01

    This article describes how in early mathematics learning, young children are often asked to recognize and describe visual patterns in their environment--perhaps on their clothing, a toy, or the carpet; around a picture frame; or in the playground equipment. Exploring patterns in the early years is seen as an important introduction to algebraic…

  20. Patterning roadmap: 2017 prospects

    Science.gov (United States)

    Neisser, Mark

    2017-06-01

    Road mapping of semiconductor chips has been underway for over 20 years, first with the International Technology Roadmap for Semiconductors (ITRS) roadmap and now with the International Roadmap for Devices and Systems (IRDS) roadmap. The original roadmap was mostly driven bottom up and was developed to ensure that the large numbers of semiconductor producers and suppliers had good information to base their research and development on. The current roadmap is generated more top-down, where the customers of semiconductor chips anticipate what will be needed in the future and the roadmap projects what will be needed to fulfill that demand. The More Moore section of the roadmap projects that advanced logic will drive higher-resolution patterning, rather than memory chips. Potential solutions for patterning future logic nodes can be derived as extensions of `next-generation' patterning technologies currently under development. Advanced patterning has made great progress, and two `next-generation' patterning technologies, EUV and nanoimprint lithography, have potential to be in production as early as 2018. The potential adoption of two different next-generation patterning technologies suggests that patterning technology is becoming more specialized. This is good for the industry in that it lowers overall costs, but may lead to slower progress in extending any one patterning technology in the future.

  1. Is It a Pattern?

    Science.gov (United States)

    McGarvey, Lynn M.

    2013-01-01

    This article describes how in early mathematics learning, young children are often asked to recognize and describe visual patterns in their environment--perhaps on their clothing, a toy, or the carpet; around a picture frame; or in the playground equipment. Exploring patterns in the early years is seen as an important introduction to algebraic…

  2. REE distribution characteristics of sewage irrigation in Sidaoshahe basin of Baotou City%包头市四道沙河流域污灌区稀土元素的分布特征

    Institute of Scientific and Technical Information of China (English)

    张庆辉; 王贵; 赵捷; 朱晋; 程莉; 同丽嘎

    2012-01-01

    [Objective] The research was to study characteristics of rare earth elements (REE) distribution in stream sediment and farmland surface soil of sewage irrigation in Sidaoshahe basin of Baotou, providing a scientific basis to evaluate the soil environmental quality of sewage irrigation area and repair of heavy metal pollution in soil. [Method] Stream sediments and farmland soils samples were collected in Sidaoshahe basin in the southern suburbs of Baotou to determine the content of REE. Distribution characteris- tics and fractionation characteristics were analyzed systematically in stream sediments and farmland soils. [Result] The results indicated that the average total content of light rare earth elements (LRE) was 42.43 times of heavy rare earth elements(HRE). The value of ∑LRE/∑ HRE was 12. 36--128. 72, LRE and HRE separated obviously,showing LRE relatively rich. Eu was relatively slightly lost and Ce showed significantly abnormal in some places. [Conclusion] Full enrichment LRE was found in the study area because human activities lead to excess accumulation of exogenous LRE in the environment of sewage irrigation, external LRE to soil ecological environment in sewage irrigation in the southern suburbs of Baotou City has a significant impact.%【目的】研究包头四道沙河流域污灌区水系沉积物、表层土壤中的稀土元素分布特征,旨在为污灌区的土壤环境质量评价及土壤重金属污染修复提供依据。【方法】采集包头市南郊四道沙河流域污灌区的水系沉积物、农田土壤样品,测定样品中不同稀土元素含量,系统分析污灌区水系沉积物、农田土壤中的稀土元素分布特征和分馏特征。【结果】污灌区的轻稀土元素总量是重稀土元素的42.43倍,轻稀土元素与重稀土元素总量的比值为12.36~128.72。研究区轻、重稀土元素分馏非常明显,且以轻稀土元素的富集度较高,Eu元素有相对微弱亏损,Ce元素在

  3. Parallel Algorithms and Patterns

    Energy Technology Data Exchange (ETDEWEB)

    Robey, Robert W. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-06-16

    This is a powerpoint presentation on parallel algorithms and patterns. A parallel algorithm is a well-defined, step-by-step computational procedure that emphasizes concurrency to solve a problem. Examples of problems include: Sorting, searching, optimization, matrix operations. A parallel pattern is a computational step in a sequence of independent, potentially concurrent operations that occurs in diverse scenarios with some frequency. Examples are: Reductions, prefix scans, ghost cell updates. We only touch on parallel patterns in this presentation. It really deserves its own detailed discussion which Gabe Rockefeller would like to develop.

  4. Statistical Pattern Recognition

    CERN Document Server

    Webb, Andrew R

    2011-01-01

    Statistical pattern recognition relates to the use of statistical techniques for analysing data measurements in order to extract information and make justified decisions.  It is a very active area of study and research, which has seen many advances in recent years. Applications such as data mining, web searching, multimedia data retrieval, face recognition, and cursive handwriting recognition, all require robust and efficient pattern recognition techniques. This third edition provides an introduction to statistical pattern theory and techniques, with material drawn from a wide range of fields,

  5. PATTERN MATCHING IN MODELS

    Directory of Open Access Journals (Sweden)

    Cristian GEORGESCU

    2005-01-01

    Full Text Available The goal of this paper is to investigate how such a pattern matching could be performed on models,including the definition of the input language as well as the elaboration of efficient matchingalgorithms. Design patterns can be considered reusable micro-architectures that contribute to anoverall system architecture. Frameworks are also closely related to design patterns. Componentsoffer the possibility to radically change the behaviors and services offered by an application bysubstitution or addition of new components, even a long time after deployment. Software testing isanother aspect of reliable development. Testing activities mainly consist in ensuring that a systemimplementation conforms to its specifications.

  6. Pattern Formation in Hydrozoa

    Science.gov (United States)

    Berking, Stefan

    The fresh water polyp Hydra is famous for its ability to regenerate missing structures. Even aggregates of single cells transform eventually into normally shaped animals. This indicates a communication within the tissue and within the aggregates which determines the spatial pattern of gene expression. Such pattern-forming systems are thought to play a decisive role in the control of self-organization during embryogenesis. Marine and fresh water hydrozoa appear to allow an access to such a system. Although the molecular components are still mostly unknown, the regulatory properties of the pattern-forming system are increasingly well understood, and this may help eventually to identify the components involved.

  7. Pattern based morphometry.

    Science.gov (United States)

    Gaonkar, Bilwaj; Pohl, Kilian; Davatzikos, Christos

    2011-01-01

    Voxel based morphometry (VBM) is widely used in the neuroimaging community to infer group differences in brain morphology. VBM is effective in quantifying group differences highly localized in space. However it is not equally effective when group differences might be based on interactions between multiple brain networks. We address this by proposing a new framework called pattern based morphometry (PBM). PBM is a data driven technique. It uses a dictionary learning algorithm to extract global patterns that characterize group differences. We test this approach on simulated and real data obtained from ADNI. In both cases PBM is able to uncover complex global patterns effectively.

  8. Multiscale conformal pattern transfer

    Science.gov (United States)

    Lodewijks, Kristof; Miljkovic, Vladimir; Massiot, Inès; Mekonnen, Addis; Verre, Ruggero; Olsson, Eva; Dmitriev, Alexandre

    2016-06-01

    We demonstrate a method for seamless transfer from a parent flat substrate of basically any lithographic top-down or bottom-up pattern onto essentially any kind of surface. The nano- or microscale patterns, spanning macroscopic surface areas, can be transferred with high conformity onto a large variety of surfaces when such patterns are produced on a thin carbon film, grown on top of a sacrificial layer. The latter allows lifting the patterns from the flat parent substrate onto a water-air interface to be picked up by the host surface of choice. We illustrate the power of this technique by functionalizing broad range of materials including glass, plastics, metals, rough semiconductors and polymers, highlighting the potential applications in in situ colorimetry of the chemistry of materials, anti-counterfeit technologies, biomolecular and biomedical studies, light-matter interactions at the nanoscale, conformal photovoltaics and flexible electronics.

  9. The Optimal Fishing Pattern

    NARCIS (Netherlands)

    Kolding, J.; Law, R.; Plank, M.; Zwieten, van P.A.M.

    2016-01-01

    Conventional fisheries management encourages highly selective fishing patterns for various purposes, such as increase relative yield, reduce unwanted bycatch, protect various species or sizes and rebuild ecosystems. Recent empirical and theoretical studies, however, show increasing evidence that

  10. Antenna Pattern Range (APR)

    Data.gov (United States)

    Federal Laboratory Consortium — TheAntenna Pattern Range (APR)features a non-metallic arch with a trolley to move the transmit antenna from the horizon to zenith. At the center of the ground plane,...

  11. Hyponymy Patterns in Romanian

    Directory of Open Access Journals (Sweden)

    Verginica Barbu Mititelu

    2011-10-01

    Full Text Available Hyponymy is a lexical-semantic relation that has been studied in Romanian linguistics only occasionally and almost exclusively in connection to other relations. However, for computational engineers it offers a very effective way of organizing the lexical material useful in many applications involving Natural Language Processing. In this paper we present two methods of identifying Romanian hyponymy patterns, their results and evaluation; we also envisage the applicability of these patterns and future work

  12. Pattern recognition of quantum information based on pattern-distance

    Institute of Scientific and Technical Information of China (English)

    Dong Daoyi; Chen Zonghai; Jiang Shengxiang

    2005-01-01

    Looking upon every encoding state of quantum information systems as a quantum information pattern, A kind of pattern-distance between different patterns as a measurement of comparability of quantum information patterns is defined, and two kinds of recognition algorithms based on pattern-distance for quantum information are proposed. They can respectively recognize quantum information with known objective pattern and unknown objective pattern. In the two algorithms, the phases and occurrence probabilities of different eigenpatterns of quantum information are sufficiently considered. Two examples demonstrate the feasibility and effectiveness of the two recognition methods. These algorithms point out a new and important path for applications of quantum information and pattern recognition.

  13. Pre-Service Mathematics Teachers' Pattern Conversion Ability: Generating Figural Patterns Based on Number Patterns

    Science.gov (United States)

    Kiliç, Çigdem

    2017-01-01

    In that current study, pattern conversion ability of 25 pre-service mathematics teachers (producing figural patterns following number patterns) was investigated. During the study participants were asked to generate figural patterns based on those number patterns. The results of the study indicate that many participants could generate different…

  14. Understanding Exhaustive Pattern Learning

    CERN Document Server

    Shen, Libin

    2011-01-01

    Pattern learning in an important problem in Natural Language Processing (NLP). Some exhaustive pattern learning (EPL) methods (Bod, 1992) were proved to be flawed (Johnson, 2002), while similar algorithms (Och and Ney, 2004) showed great advantages on other tasks, such as machine translation. In this article, we first formalize EPL, and then show that the probability given by an EPL model is constant-factor approximation of the probability given by an ensemble method that integrates exponential number of models obtained with various segmentations of the training data. This work for the first time provides theoretical justification for the widely used EPL algorithm in NLP, which was previously viewed as a flawed heuristic method. Better understanding of EPL may lead to improved pattern learning algorithms in future.

  15. General human activity patterns

    CERN Document Server

    Mollgaard, Anders; Mathiesen, Joachim

    2016-01-01

    We investigate the dynamics and interplay between human communication, movement, and social proximity by analyzing data collected from smartphones distributed among 638 individuals. The main question we consider is: to what extent do individuals act according to patterns shared across an entire population? Based on statistics of the entire population, we successfully predict 71\\% of the activity and 85\\% of the inactivity involved in communication, movement, and social proximity. We find that individual level statistics only result in marginally better predictions, indicating a high degree of shared activity patterns across the population. Finally, we predict short-term activity patterns using a generalized linear model, which suggests that a simple linear description might be sufficient to explain a wide range of actions, whether they be of social or of physical character.

  16. Patterns of Internationalization

    DEFF Research Database (Denmark)

    Prockl, Günter; Kotzab, Herbert; Kinra, Aseem

    2013-01-01

    , and infact show different patterns to their international development. However, there are other important transactional and market-oriented considerations, and overall dynamics that need to be examined before concluding on the internationalization levels of container shipping companies, and the industry....... The purpose of this paper is to further investigate the patterns of internationalisation by the examination of the more demand-oriented considerations. Design/methodology/approach - In order to answer the research question, the paper focusses on the examination of the front-end activities and structures like...... for the worldwide presence of a company. Research limitations/implications (if applicable) - The paper adds yet another piece to the interesting puzzle on internationalization patterns of container shipping companies. However, for a complete picture on the internationalization process further work will be required...

  17. G ∘ F Patterns

    CERN Document Server

    CERN. Geneva

    2017-01-01

    The book of design patterns known as Gang of Four has been a kind of Bible for all the developers of my generation. Its main pro has been giving us a common vocabulary: when a programmer says “here I used a strategy pattern” all colleagues know of what he is speaking about. Nevertheless the biggest issue with this is that almost all patterns listed in that book, especially the behavioural ones, are a only workaround for a missing abstraction: higher order functions. The introduction of lambda expressions in Java 8 finally allows all Java developers to remove this no longer necessary and cumbersome object oriented infrastructure from their code. The purpose of this talk is showing, through a series of live coding examples, how the most common GoF patterns can be rethought and reimplemented in a simpler and more concise functional way leveraging Java 8 lambdas.

  18. Enzymatic pattern processing

    Science.gov (United States)

    Zauner, Klaus-Peter; Conrad, M.

    A table-top prototype has been constructed that uses the enzyme malate dehydrogenase to recognize input signal patterns. The device is controlled by the enzyme in response to injection of Mg2+ used as a signaling substance. Output is monitored spectroscopically. If Mg2+ is injected along either of two signal lines (i.e., if the input signal pattern is 10 or 01) the device emits an output of 1. Injection along neither or both lines results in an output of 0. The enzyme in effect is used as a transform that converts the linearly inseparable exclusive-or problem into a linearly separable problem.

  19. Workflow User Interfaces Patterns

    Directory of Open Access Journals (Sweden)

    Jean Vanderdonckt

    2012-03-01

    Full Text Available Este trabajo presenta una colección de patrones de diseño de interfaces de usuario para sistemas de información para el flujo de trabajo; la colección incluye cuarenta y tres patrones clasificados en siete categorías identificados a partir de la lógica del ciclo de vida de la tarea sobre la base de la oferta y la asignación de tareas a los responsables de realizarlas (i. e. recursos humanos durante el flujo de trabajo. Cada patrón de la interfaz de usuario de flujo de trabajo (WUIP, por sus siglas en inglés se caracteriza por las propiedades expresadas en el lenguaje PLML para expresar patrones y complementado por otros atributos y modelos que se adjuntan a dicho modelo: la interfaz de usuario abstracta y el modelo de tareas correspondiente. Estos modelos se especifican en un lenguaje de descripción de interfaces de usuario. Todos los WUIPs se almacenan en una biblioteca y se pueden recuperar a través de un editor de flujo de trabajo que vincula a cada patrón de asignación de trabajo a su WUIP correspondiente.A collection of user interface design patterns for workflow information systems is presented that contains forty three resource patterns classified in seven categories. These categories and their corresponding patterns have been logically identified from the task life cycle based on offering and allocation operations. Each Workflow User Interface Pattern (WUIP is characterized by properties expressed in the PLML markup language for expressing patterns and augmented by additional attributes and models attached to the pattern: the abstract user interface and the corresponding task model. These models are specified in a User Interface Description Language. All WUIPs are stored in a library and can be retrieved within a workflow editor that links each workflow pattern to its corresponding WUIP, thus giving rise to a user interface for each workflow pattern.

  20. Structural patterns in nature

    DEFF Research Database (Denmark)

    Wester, Ture

    2003-01-01

    It seemens that some very basic randomly produced geometric/topological patterns are commonly found in Nature and have often very distinctive structural qualities. In Nature we find the same pattern in all scales from the universe to molecules, from solar systems to packing of cells, from glaciers...... to sea shells, from river systems to trees etc. Sometimes this seeming archetypical morphology involve structrual action and sometimes not-but the fact that it often posses efficient structural action opens a tool for evaluation and analysis of structures in nature and at the same time might...

  1. Structural patterns in nature

    DEFF Research Database (Denmark)

    Wester, Ture

    2004-01-01

    It seems that some very basic randomly produced geometric/topological patterns are commonly found in Nature and have often very distinctive structural qualities. In nature we find the same pattern in all scales from the universe to molecules, from solar systems to packing of cells, from glaciers...... to sea shells, from river systems to trees etc. Sometimes this seeming archetypical morphology involve structural action and sometimes not - but the fact that it often posses efficient structural action opens a tool for evaluation and analyses of structures in nature and at the same time might...

  2. Phyllotactic Patterns on Plants

    Science.gov (United States)

    Shipman, Patrick D.; Newell, Alan C.

    2004-04-01

    We demonstrate how phyllotaxis (the arrangement of leaves on plants) and the deformation configurations seen on plant surfaces may be understood as the energy-minimizing buckling pattern of a compressed shell (the plant's tunica) on an elastic foundation. The key new idea is that the strain energy is minimized by configurations consisting of special triads of almost periodic deformations. We reproduce a wide spectrum of plant patterns, all with the divergence angles observed in nature, and show how the occurrences of Fibonacci-like sequences and the golden angle are natural consequences.

  3. Patterns of orbital disorders

    Directory of Open Access Journals (Sweden)

    Balasubramanian Thiagarajan

    2014-08-01

    Full Text Available This article discusses various patterns of presentations of orbital lesions. Since this article has been authored by an otolaryngologist, the entire concept has been viewed from otolaryngologist's angle. With the advent of nasal endoscope trans nasal access to orbit is becoming the order of the day. Major advantage being that external skin incision is avoided.

  4. Understanding taxi travel patterns

    Science.gov (United States)

    Cai, Hua; Zhan, Xiaowei; Zhu, Ji; Jia, Xiaoping; Chiu, Anthony S. F.; Xu, Ming

    2016-09-01

    Taxis play important roles in modern urban transportation systems, especially in mega cities. While providing necessary amenities, taxis also significantly contribute to traffic congestion, urban energy consumption, and air pollution. Understanding the travel patterns of taxis is thus important for addressing many urban sustainability challenges. Previous research has primarily focused on examining the statistical properties of passenger trips, which include only taxi trips occupied with passengers. However, unoccupied trips are also important for urban sustainability issues because they represent potential opportunities to improve the efficiency of the transportation system. Therefore, we need to understand the travel patterns of taxis as an integrated system, instead of focusing only on the occupied trips. In this study we examine GPS trajectory data of 11,880 taxis in Beijing, China for a period of three weeks. Our results show that taxi travel patterns share similar traits with travel patterns of individuals but also exhibit differences. Trip displacement distribution of taxi travels is statistically greater than the exponential distribution and smaller than the truncated power-law distribution. The distribution of short trips (less than 30 miles) can be best fitted with power-law while long trips follow exponential decay. We use radius of gyration to characterize individual taxi's travel distance and find that it does not follow a truncated power-law as observed in previous studies. Spatial and temporal regularities exist in taxi travels. However, with increasing spatial coverage, taxi trips can exhibit dual high probability density centers.

  5. Patterning of somatosympathetic reflexes

    Science.gov (United States)

    Kerman, I. A.; Yates, B. J.

    1999-01-01

    In a previous study, we reported that vestibular nerve stimulation in the cat elicits a specific pattern of sympathetic nerve activation, such that responses are particularly large in the renal nerve. This patterning of vestibulosympathetic reflexes was the same in anesthetized and decerebrate preparations. In the present study, we report that inputs from skin and muscle also elicit a specific patterning of sympathetic outflow, which is distinct from that produced by vestibular stimulation. Renal, superior mesenteric, and lumbar colonic nerves respond most strongly to forelimb and hindlimb nerve stimulation (approximately 60% of maximal nerve activation), whereas external carotid and hypogastric nerves were least sensitive to these inputs (approximately 20% of maximal nerve activation). In contrast to vestibulosympathetic reflexes, the expression of responses to skin and muscle afferent activation differs in decerebrate and anesthetized animals. In baroreceptor-intact animals, somatosympathetic responses were strongly attenuated (to 150 mmHg. These findings demonstrate that different types of somatic inputs elicit specific patterns of sympathetic nerve activation, presumably generated through distinct neural circuits.

  6. Mastering Python design patterns

    CERN Document Server

    Kasampalis, Sakis

    2015-01-01

    This book is for Python programmers with an intermediate background and an interest in design patterns implemented in idiomatic Python. Programmers of other languages who are interested in Python can also benefit from this book, but it would be better if they first read some introductory materials that explain how things are done in Python.

  7. A Pattern Measure

    CERN Document Server

    Klinger, Allen

    2011-01-01

    In this paper we propose numerical measures for evaluating the aesthetic interest of simple patterns. The patterns consist of elements (symbols, pixels, etc.) in regular square arrays. The measures depend on two characteristics of the patterns: the number of different types of element, and the number of symmetries in their arrangement. We define two complementary composite measures L and C for the degree of pattern in a design, and compute them here for 2x2 and 6x6 arrays. The results distinguish simple from high-variation cases. We suspect that the measure L corresponds to the degree that human beings intuitively feel a design to be "interesting", so this model would aid in quantifying the visual connection of two- dimensional designs with viewers. The other composite measure C based on these numerical properties characterizes the extent of randomness of an array. Combining symbol variety with symmetry calculations allows us to employ hierarchical scaling to count the relative impact of different levels of s...

  8. Life History Patterns

    DEFF Research Database (Denmark)

    Jones, Owen

    2016-01-01

    Maximum longevity varies hugely across species, ranging from days to millennia. Reproductive output also varies by orders of magnitude. These patterns result from demographic age-trajectories of mortality and fertility, which show comparable diversity. The familiar demographic trajectories of hum...

  9. Exploring pedestrian movement patterns

    NARCIS (Netherlands)

    Orellana, D.A.

    2012-01-01

    The main objective of this thesis is to develop an approach for exploring, analysing and interpreting movement patterns of pedestrians interacting with the environment. This objective is broken down in sub-objectives related to four research questions. A case study of the movement of visitors in a n

  10. Calculating cellulose diffraction patterns

    Science.gov (United States)

    Although powder diffraction of cellulose is a common experiment, the patterns are not widely understood. The theory is mathematical, there are numerous different crystal forms, and the conventions are not standardized. Experience with IR spectroscopy is not directly transferable. An awful error, tha...

  11. Storyboards for Meaningful Patterns

    Science.gov (United States)

    Dubon, Lucille P.; Shafer, Kathryn G.

    2010-01-01

    The initial focus of this kindergarten-level action research project was on identifying which students could create a pattern. The focus then shifted to helping all students successfully achieve this goal. The intervention uses a storyboard where students select colored cubes to represent objects and then snap the cubes together as indicated on…

  12. Computational Thinking Patterns

    Science.gov (United States)

    Ioannidou, Andri; Bennett, Vicki; Repenning, Alexander; Koh, Kyu Han; Basawapatna, Ashok

    2011-01-01

    The iDREAMS project aims to reinvent Computer Science education in K-12 schools, by using game design and computational science for motivating and educating students through an approach we call Scalable Game Design, starting at the middle school level. In this paper we discuss the use of Computational Thinking Patterns as the basis for our…

  13. Subsidiary Linkage Patterns

    DEFF Research Database (Denmark)

    Andersson, Ulf; Perri, Alessandra; Nell, Phillip C.

    2012-01-01

    This paper investigates the pattern of subsidiaries' local vertical linkages under varying levels of competition and subsidiary capabilities. Contrary to most previous literature, we explicitly account for the double role of such linkages as conduits of learning prospects as well as potential...

  14. Exploring pedestrian movement patterns

    NARCIS (Netherlands)

    Orellana, D.A.

    2012-01-01

    The main objective of this thesis is to develop an approach for exploring, analysing and interpreting movement patterns of pedestrians interacting with the environment. This objective is broken down in sub-objectives related to four research questions. A case study of the movement of visitors in a n

  15. Spider Web Pattern

    Science.gov (United States)

    2006-01-01

    A delicate pattern, like that of a spider web, appears on top of the Mars residual polar cap, after the seasonal carbon-dioxide ice slab has disappeared. Next spring, these will likely mark the sites of vents when the carbon-dioxide ice cap returns. This Mars Global Surveyor, Mars Orbiter Camera image is about 3-kilometers wide (2-miles).

  16. Reconfigurable antenna pattern verification

    Science.gov (United States)

    Drexler, Jerome P. (Inventor); Becker, Robert C. (Inventor); Meyers, David W. (Inventor); Muldoon, Kelly P. (Inventor)

    2013-01-01

    A method of verifying programmable antenna configurations is disclosed. The method comprises selecting a desired antenna configuration from a plurality of antenna configuration patterns, with the selected antenna configuration forming at least one reconfigurable antenna from reconfigurable antenna array elements. The method validates the formation of the selected antenna configuration to determine antenna performance of the at least one reconfigurable antenna.

  17. Pattern recognition in bioinformatics.

    Science.gov (United States)

    de Ridder, Dick; de Ridder, Jeroen; Reinders, Marcel J T

    2013-09-01

    Pattern recognition is concerned with the development of systems that learn to solve a given problem using a set of example instances, each represented by a number of features. These problems include clustering, the grouping of similar instances; classification, the task of assigning a discrete label to a given instance; and dimensionality reduction, combining or selecting features to arrive at a more useful representation. The use of statistical pattern recognition algorithms in bioinformatics is pervasive. Classification and clustering are often applied to high-throughput measurement data arising from microarray, mass spectrometry and next-generation sequencing experiments for selecting markers, predicting phenotype and grouping objects or genes. Less explicitly, classification is at the core of a wide range of tools such as predictors of genes, protein function, functional or genetic interactions, etc., and used extensively in systems biology. A course on pattern recognition (or machine learning) should therefore be at the core of any bioinformatics education program. In this review, we discuss the main elements of a pattern recognition course, based on material developed for courses taught at the BSc, MSc and PhD levels to an audience of bioinformaticians, computer scientists and life scientists. We pay attention to common problems and pitfalls encountered in applications and in interpretation of the results obtained.

  18. Travel patterns in China.

    Directory of Open Access Journals (Sweden)

    Tini Garske

    Full Text Available The spread of infectious disease epidemics is mediated by human travel. Yet human mobility patterns vary substantially between countries and regions. Quantifying the frequency of travel and length of journeys in well-defined population is therefore critical for predicting the likely speed and pattern of spread of emerging infectious diseases, such as a new influenza pandemic. Here we present the results of a large population survey undertaken in 2007 in two areas of China: Shenzhen city in Guangdong province, and Huangshan city in Anhui province. In each area, 10,000 randomly selected individuals were interviewed, and data on regular and occasional journeys collected. Travel behaviour was examined as a function of age, sex, economic status and home location. Women and children were generally found to travel shorter distances than men. Travel patterns in the economically developed Shenzhen region are shown to resemble those in developed and economically advanced middle income countries with a significant fraction of the population commuting over distances in excess of 50 km. Conversely, in the less developed rural region of Anhui, travel was much more local, with very few journeys over 30 km. Travel patterns in both populations were well-fitted by a gravity model with a lognormal kernel function. The results provide the first quantitative information on human travel patterns in modern China, and suggest that a pandemic emerging in a less developed area of rural China might spread geographically sufficiently slowly for containment to be feasible, while spatial spread in the more economically developed areas might be expected to be much more rapid, making containment more difficult.

  19. Double-pattern associative memory neural network with pattern loop

    Institute of Scientific and Technical Information of China (English)

    Jian WANG; Zongyuan MAO

    2004-01-01

    A double-patrern associative memory neural network with "pattern loop" is proposed. It can store 2N bit bipolar binary Patterns up to the order of 22N, retrieve part or all of the stored patrems which all have the minimum Hamming distance with input Pattern, completely eliminate spurious Patterns, and has higher storing efficiency and reliability than conventional associative memory. The length of a Pattern stored in this associative memory can be easily extended from 2N to kN.

  20. REE Geochemical Characteristics of the Cambrian Carbonaceous Rock Series in the Mian-Liie Region and Their Genetical Implications%勉略地区寒武纪含碳岩系稀土元素地球化学特征及成因意义

    Institute of Scientific and Technical Information of China (English)

    乔耿彪; 杨钟堂; 李智明; 杨晓勇; 蓝翔华

    2011-01-01

    The authors analyzed REE contents of the Cambrian carbonaceous rock series in the Mian-Liie region by using ICP - MS method in order to investigate their geochemical characteristics and genetic implications. Some conclusions can be reached from the acquired analytical data: the carbonaceous rock series show narrow variation in the total contents of rare earth elements (∑REE),from 167. 88×10-6 to 210. 50×10-6 with an average at 192. 20 × 10-6; the ratios of LREE/HREE vary from 6. 64 to 16. 25 with an average at 11. 52, showing relative enrichment of LREE and depletion in HREE; the carbonaceous rock series show remarkable negative Ce anomalies, varying from 0. 58 to 0. 90 (0. 78 on average ), suggesting that the carbonaceous rock series formed in a dry and anoxic sedimentary environment close to a marginal sea of continental slope; The carbonaceous rock series also show distinctly negative Eu anomalies, δEuN =0. 47 - 0. 83(0. 62 on average),suggesting that they formed in a passive continental margin environment as products of normal marine sediments under low temperature(<250℃) diagenesis, consistent with the their geotectonic location in the northern margin of the Yangtze platform ;according to the diagrams of La/Yb - Ce/La and La/Yb - REE, it is also confirmed that the carbonaceous rock series not formed in a hydrothermal sedimentary condition but in a normal marine condition with their main source materials coming from a continental crust with high quartz content.%采用等离子质仪(ICP - MS)测试方法对岩石的稀土元素含量进行了测定,探讨了勉略地区寒武纪含碳岩系的稀土元素地球化学特征及其成因.研究表明:含碳岩系岩石的稀土元素总量(∑REE)总体变化不大,质量分数为(167.88~210.50)×10-6,平均为192.20×10-6;轻重稀土比值(LREE/HREE)为6.64~16.25.平均为11.52,显示轻稀土富集而重稀土亏损;含碳岩系岩石具明显的Ce负异常,δCeN值为0.58~0.90(平均为0

  1. 山东微山稀土矿矿床成因:来自云母Rb-Sr年龄、激光Nd同位素及流体包裹体的证据%Genesis of the Weishan REE deposit, Shandong Province: Evidences from Rb-Sr isochron age, LA-MC-ICPMS Nd isotopic compositions and fluid inclusions

    Institute of Scientific and Technical Information of China (English)

    蓝廷广; 范宏瑞; 胡芳芳; 杨奎锋; 王永

    2011-01-01

    Weishan REE deposit, a pegmatite-type REE deposit related to alkaline rocks, is located in Luxi Block, southeastern North China Craton. Muscovite Rb-Sr isochron yields an age of 119.5 Ma, which belonged to the Early Cretaceous large-scale mineralization in the North China Craton. LA-ICPMS Nd isotopic compositions of bastnaesite and monazite indicate that the source of the REE deposit is the enriched lithospheric mantle. Four types of fluid inclusions have been identified in quartz, fluorite and barite, including (1) H2O inclusions (H), (2) pure CO2 inclusions (C), (3) H2O+CO2 inclusions (HC) and (4) H2O+CO2+daughter mineral inclusions (HCD). The H inclusions are secondary while others are primary. The daughter minerals in HCD inclusions include thenardite, barite, celestine, calcite, aphthitalite and glauberite. The homogenization and capture pressures of HC and HCD inclusions range from 205-433 ℃ and 120-200 Mpa, respectively. Coupled with the existence of abundant daughter minerals and S stable isotopic compositions, it can be deduced that the initial ore-forming fluidswere high-temperature, moderate-pressure and high-concentration orthomagmatic fluids, which were characterized by enrichment of HCO-3/CO2-3, SO2-4 and F~ and multi-component (e.g., Na+, K+, Ca+, Ba2+, Sr2+ and REE3+). The coexistence of C, HC and HCD inclusions and the wide range of liquid/vapor ratios between these inclusions suggest that fluid unmixing may have occurred during ore-forming process. REE were most probably transported as [REEF]2+ and precipitated through fluid unmixing. Fluids mixing, which contributed little to the REE precipitation, also happened in the late stage of the ore-forming process.%微山稀土矿位于华北克拉通东南缘的鲁西地块,为与碱性岩相关的伟晶岩型稀土矿床.根据单颗粒云母Rb-Sr定年,其形成于119.5 Ma,属于华北克拉通早白垩世大规模成矿事件的一部分.稀土矿物氟碳铈矿和独居石的激光Nd同位素研

  2. Break the Pattern!

    DEFF Research Database (Denmark)

    Hasse, Cathrine; Trentemøller, Stine

    Break the Pattern! A critical enquiry into three scientific workplace cultures: Hercules, Caretakers and Worker Bees is the third publication of the international three year long project "Understanding Puzzles in the Gendered European Map" (UPGEM). By contrasting empirical findings from academic...... workplaces in the five UPGEM-countries (Denmark, Estonia, Finland, Italy and Poland) we identify three clusters of cultural patterns in physics as culture. We call these Hercules, Caretakers and Worker Bees. We also consider the influence of national cultural historical processes on the scientific culture...... (physics in culture) and discuss how physics as and in culture influence the perception of science, of work and family life, of the interplay between religion and science as well as how physics as culture can either hinder or promote the career of female scientists....

  3. Dietary Patterns in Childhood

    DEFF Research Database (Denmark)

    Andersen, Louise Beltoft Borup

    A healthy diet is essential for healthy growth and development during childhood and may prevent obesity, diabetes, and cardiovascular diseases throughout life. Traditionally, diet has been investigated as single nutrients. However, people do not eat one single nutrient and they do not even eat one...... nutrients. However, little is known about the development of dietary patterns in childhood both in relation to possible indicators and to obesity related outcomes. Therefore, the aim of this PhD thesis was to make exploratory analyses of dietary patterns in childhood using the method principal component...... analysis (PCA) and to investigate associations to possible indicators and outcomes related to growth and obesity. This was based on two observational cohort studies (SKOT I, SKOT II) and one intervention study (MoMS). The research showed that PCA is a suitable method for understanding some...

  4. Patterns of Flux Emergence

    Science.gov (United States)

    Title, A.; Cheung, M.

    2008-05-01

    The high spatial resolution and high cadence of the Solar Optical Telescope on the JAXA Hinode spacecraft have allowed capturing many examples of magnetic flux emergence from the scale of granulation to active regions. The observed patterns of emergence are quite similar. Flux emerges as a array of small bipoles on scales from 1 to 5 arc seconds throughout the region that the flux eventually condenses. Because the fields emerging from the underlying flux rope my appear many in small segments and the total flux (absolute sum) is not a conserved quantity the amount of total flux on the surface may vary significantly during the emergence process. Numerical simulations of flux emergence exhibit patterns similar to observations. Movies of both observations and numerical simulations will be presented.

  5. Settlement patterns and sustainability

    DEFF Research Database (Denmark)

    Hendriksen, Kåre

    This paper discusses settlement patterns and sustainability. Generally urbanization is recognised as an inevitable development driven by job opportunities, better service supply, education, and health services, and it is argued that this is the main driver for centralisation. Research based...... of utilization of local resources and trade opportunities. Furthermore the growing towns are struggling with an un-sustainable economic situation manly based on public financed jobs or welfare payments and with limited export oriented value creation....... on economic and demographic studies and a large series of interviews problematize this. In Greenland the historical correlation between settlement pattern and livelihood has been decoupled, so that distributions of jobs and potential earnings to a growing extend is a consequence of political and...

  6. Constraints in using Cerium-animaly of bulk sediments as an indicator of paleo bottom water redox environment: A case study from the Central Indian Ocean Basin

    Digital Repository Service at National Institute of Oceanography (India)

    Pattan, J.N.; Pearce, N.J.G.; Mislankar, P.G.

    abundance shows a nearly two fold increase (Sigma REE=167-341 ppm) with depth and the REE strongly co-varies with Mn, Ti, P and smectite. Inter-element correlations and the shale-normalized REE patterns suggest that light, middle and heavy REE...

  7. Geochemical trends in the sediments and manganese nodules from a part of the Central Indian Basin

    Digital Repository Service at National Institute of Oceanography (India)

    Banakar, V.K.; Jauhari, P.

    -hydroxide colloidal flocs incorporating into the nodules. The shale (NASC) normalised patterns and end member ratios of REE indicate middle REE(MREE) enrichment over light REE(LREE) and heavy REE(HREE) in both nodules and sediments. The preferential uptake sequence...

  8. Patterns of ESS's. II.

    Science.gov (United States)

    Cannings, C; Vickers, G T

    1988-06-22

    For symmetric matrix conflicts with aij = +/- 1 and aii = 0, an ESS corresponds to a clique in an associated graph. This result is proved and exploited to yield results on the attainable patterns for this class of conflicts and bounds for the number of ESS's which may coexist. Randomly generated matrices in this class are considered, and some results on the size of the support of a typical ESS given.

  9. Pattern Based Morphometry

    OpenAIRE

    Gaonkar, Bilwaj; Pohl, Kilian; Davatzikos, Christos

    2011-01-01

    Voxel based morphometry (VBM) is widely used in the neuroimaging community to infer group differences in brain morphology. VBM is effective in quantifying group differences highly localized in space. However it is not equally effective when group differences might be based on interactions between multiple brain networks. We address this by proposing a new framework called pattern based morphometry (PBM). PBM is a data driven technique. It uses a dictionary learning algorithm to extract global...

  10. Secure Design Patterns

    Science.gov (United States)

    2009-10-01

    administering a system or debugging a new system. In addition, the information contained in a system log may contain information that could be used by an...puts. The presented solution is programmed in PHP . • “Client/Server Input Validation Using MS ATL Server Libraries” [MSDN 2009c]. This pro- vides an...www.devshed.com/c/a/ PHP /Validating-User-Input-with-the-Strategy-Pattern/ [Kernighan 1999] Kernighan, Brian W. & Pike, Rob. The Practice of

  11. Clustering by Pattern Similarity

    Institute of Scientific and Technical Information of China (English)

    Hai-xun Wang; Jian Pei

    2008-01-01

    The task of clustering is to identify classes of similar objects among a set of objects. The definition of similarity varies from one clustering model to another. However, in most of these models the concept of similarity is often based on such metrics as Manhattan distance, Euclidean distance or other Lp distances. In other words, similar objects must have close values in at least a set of dimensions. In this paper, we explore a more general type of similarity. Under the pCluster model we proposed, two objects are similar if they exhibit a coherent pattern on a subset of dimensions. The new similarity concept models a wide range of applications. For instance, in DNA microarray analysis, the expression levels of two genes may rise and fall synchronously in response to a set of environmental stimuli. Although the magnitude of their expression levels may not be close, the patterns they exhibit can be very much alike. Discovery of such clusters of genes is essential in revealing significant connections in gene regulatory networks. E-commerce applications, such as collaborative filtering, can also benefit from the new model, because it is able to capture not only the closeness of values of certain leading indicators but also the closeness of (purchasing, browsing, etc.) patterns exhibited by the customers. In addition to the novel similarity model, this paper also introduces an effective and efficient algorithm to detect such clusters, and we perform tests on several real and synthetic data sets to show its performance.

  12. Pattern Recognition Control Design

    Science.gov (United States)

    Gambone, Elisabeth A.

    2018-01-01

    Spacecraft control algorithms must know the expected vehicle response to any command to the available control effectors, such as reaction thrusters or torque devices. Spacecraft control system design approaches have traditionally relied on the estimated vehicle mass properties to determine the desired force and moment, as well as knowledge of the effector performance to efficiently control the spacecraft. A pattern recognition approach was used to investigate the relationship between the control effector commands and spacecraft responses. Instead of supplying the approximated vehicle properties and the thruster performance characteristics, a database of information relating the thruster ring commands and the desired vehicle response was used for closed-loop control. A Monte Carlo simulation data set of the spacecraft dynamic response to effector commands was analyzed to establish the influence a command has on the behavior of the spacecraft. A tool developed at NASA Johnson Space Center to analyze flight dynamics Monte Carlo data sets through pattern recognition methods was used to perform this analysis. Once a comprehensive data set relating spacecraft responses with commands was established, it was used in place of traditional control methods and gains set. This pattern recognition approach was compared with traditional control algorithms to determine the potential benefits and uses.

  13. Blood stain pattern analysis.

    Science.gov (United States)

    Peschel, O; Kunz, S N; Rothschild, M A; Mützel, E

    2011-09-01

    Bloodstain pattern analysis (BPA) refers to the collection, categorization and interpretation of the shape and distribution of bloodstains connected with a crime. These kinds of stains occur in a considerable proportion of homicide cases. They offer extensive information and are an important part of a functional, medically and scientifically based reconstruction of a crime. The following groups of patterns can essentially be distinguished: dripped and splashed blood, projected blood, impact patterns, cast-off stains, expirated and transferred bloodstains. A highly qualified analysis can help to estimate facts concerning the location, quality and intensity of an external force. A sequence of events may be recognized, and detailed questions connected with the reconstruction of the crime might be answered. In some cases, BPA helps to distinguish between accident, homicide and suicide or to identify bloodstains originating from a perpetrator. BPA is based on systematic training, a visit to the crime scene or alternatively good photographic documentation, and an understanding and knowledge of autopsy findings or statements made by the perpetrator and/or victim. A BPA working group has been established within the German Society of Legal Medicine aiming to put the knowledge and practical applications of this subdiscipline of forensic science on a wider basis.

  14. Pattern Driven Stress Localization

    Science.gov (United States)

    Croll, Andrew; Crosby, Alfred

    2010-03-01

    The self-assembly of patterns from isotropic initial states is a major driver of modern soft-matter research. This avenue of study is directed by the desire to understand the complex physics of the varied structures found in Nature, and by technological interest in functional materials that may be derived through biomimicry. In this work we show how a simple striped phase can respond with significant complexity to an appropriately chosen perturbation. In particular, we show how a buckled elastic plate transitions into a state of stress localization using a simple, self-assembled variation in surface topography. The collection of topographic boundaries act in concert to change the state from isotropic sinusoidal wrinkles, to sharp folds or creases separated by relatively flat regions. By varying the size of the imposed topographic pattern or the wavelength of the wrinkles, we construct a state diagram of the system. The localized state has implications for both biological systems, and for the control of non-linear pattern formation.

  15. Gardosian Patterns in Tribology

    Science.gov (United States)

    DellaCorte, Christopher

    2004-01-01

    The following paper is a memorial retrospective on selected research of Dr. Michael N. Gardos. Dr. Gardos spent his professional career engaged in tribological research which often extended the scientific boundaries of the field. Several of the concepts he put forth into the tribology community were initially met with grave skepticism but over time his views have been largely embraced but not widely acknowledged. His approach to new research topics was often characterized by these qualities: 1) pioneering points of view, 2) the use of the model experiment, and 3) the presence of multiple research agendas for each single experiment. I have chosen to name his research approach as "Gardosian Patterns" in honor of his contributions to Tribology. Three specific examples of these patterns will be reviewed. One is the concept of atomic level tailoring of materials to control macroscopic properties. A second is the use of a model ball polishing experiment to identify high fracture toughness ceramics for use in rolling element bearings. A third Gardosian Pattern example is his pioneering work with the tribology of diamond and diamond films in which he proposed controlling friction via surface bond tailoring. In these examples, Gardos utilized conventional research tools in unconventional ways and, at times, even developed new tools which have become part of the mainstream. His remarkable career has left a positive and lasting mark on Tribology.

  16. Isoflurane Use in the Treatment of Super-Refractory Status Epilepticus is Associated with Hippocampal Changes on MRI.

    Science.gov (United States)

    Ikeda, Kristin M; Connors, Robert; Lee, Donald H; Khandji, Alexander G; Claassen, Jan; Young, G Bryan

    2017-06-01

    Refractory status epilepticus (RSE) is associated with high morbidity and mortality. Experts recommend aggressive management with continuous intravenous infusions or inhaled anesthetics such as isoflurane. However, there is concern that MRI changes in RSE reflect isoflurane neurotoxicity. We performed a case-control study to determine whether isoflurane is neurotoxic, based on MRI signal changes. We performed a retrospective case-control study of the incidence of MRI changes in RSE treated with and without isoflurane. Charts were reviewed for demographic and treatment information. T1, T2, and FLAIR sequences of MRIs were reviewed independently by two neuroradiologists blinded to treatment group for presence or absence of signal change or atrophy in the meninges, cortex, white matter, basal ganglia, thalamus, hippocampus, brainstem, and cerebellum. Eight cases of RSE receiving treatment with isoflurane were identified and double-matched with 15 controls who received only intravenous anesthetics. Baseline characteristics were similar. Hippocampal signal change was observed more frequently in cases receiving isoflurane (p = 0.026). Hippocampal signal changes were associated with isoflurane use in patients with RSE. They were also associated with number of seizure days prior to MRI and the use of multiple anesthetic agents. Similar changes have been seen as a result of RSE itself, and one cannot rule out the possibility these changes represent seizure-related effects. If isoflurane-related, these hippocampal signal changes may be the result of a direct neurotoxic effect of prolonged isoflurane use or failure of isoflurane to protect the hippocampus from seizure-induced injury despite achieving electrographic burst-suppression.

  17. Pig design patterns

    CERN Document Server

    Pasupuleti, Pradeep

    2014-01-01

    Pig makes Hadoop programming simple, intuitive, and fun to work with. It removes the complexity from Map Reduce programming by giving the programmer immense power through its flexibility. What used to be extremely lengthy and intricate code written in other high level languages can now be written in almost one tenth of the size using its easy to understand constructs. Pig has proven to be the easiest way to learn how to program Hadoop clusters, as evidenced by its widespread adoption. This comprehensive guide enables readers to readily use design patterns to simplify the creation of complex da

  18. Imaging patterns in melioidosis

    Energy Technology Data Exchange (ETDEWEB)

    Tan, A.P.A.; Pui, M.H.; Tan, L.K.A. [National Univ. of Singapore (Senegal). Dept. of Diagnostic Radiology

    1995-08-01

    Melioidosis is an infectious disease caused by Pseudomonas pseudomallei. It is seldom diagnosed promptly and, if untreated, can lead to an 80-100% mortality rate. Twenty-eight patients with melioidosis were identified over a 6 year period, and their imaging patterns were analysed. Respiratory infections were the commonest form of presentation, frequently shown as diffuse airspace consolidation, and accounted for the highest mortality. Visceral and musculoskeletal infections were associated with chronicity and a high relapse rate. Multifocal splenic abscesses were a common occurence. Septic arthritis of the knee was frequently seen. The majority of patients had diabetes mellitus and chronic ill health. 11 refs., 9 figs.

  19. JavaScript Patterns

    CERN Document Server

    Stefanov, Stoyan

    2010-01-01

    What's the best approach for developing an application with JavaScript? This book helps you answer that question with numerous JavaScript coding patterns and best practices. If you're an experienced developer looking to solve problems related to objects, functions, inheritance, and other language-specific categories, the abstractions and code templates in this guide are ideal -- whether you're writing a client-side, server-side, or desktop application with JavaScript. Written by JavaScript expert Stoyan Stefanov -- Senior Yahoo! Technical and architect of YSlow 2.0, the web page performance

  20. Outsourced pattern matching

    DEFF Research Database (Denmark)

    Faust, Sebastian; Hazay, Carmit; Venturi, Daniele

    2013-01-01

    on concrete and important functionalities and give the first protocol for the pattern matching problem in the cloud. Loosely speaking, this problem considers a text T that is outsourced to the cloud S by a client C T . In a query phase, clients C 1, …, C l run an efficient protocol with the server S...... that contain confidential data (e.g., health related data about patient history). Our constructions offer simulation-based security in the presence of semi-honest and malicious adversaries (in the random oracle model) and limit the communication in the query phase to O(m) bits plus the number of occurrences...

  1. How does an fMRI voxel sample the neuronal activity pattern: compact-kernel or complex spatiotemporal filter?

    Science.gov (United States)

    Kriegeskorte, Nikolaus; Cusack, Rhodri; Bandettini, Peter

    2010-02-01

    Recent studies suggested that fMRI voxel patterns can convey information represented in columnar-scale neuronal population codes, even when spatial resolution is insufficient to directly image the patterns of columnar selectivity (Kamitani and Tong, 2005; Haynes and Rees, 2005). Sensitivity to subvoxel-scale pattern information, or "fMRI hyperacuity," would greatly enhance the power of fMRI when combined with pattern information analysis techniques (Kriegeskorte and Bandettini, 2007). An individual voxel might weakly reflect columnar-level information if the columns within its boundaries constituted a slightly unbalanced sample of columnar selectivities (Kamitani and Tong, 2005), providing a possible mechanism for fMRI hyperacuity. However, Op de Beeck (2009) suggests that a coarse-scale neuronal organization rather than fMRI hyperacuity may explain the presence of the information in the fMRI patterns. Here we argue (a) that the present evidence does not rule out fMRI hyperacuity, (b) that the mechanism originally suggested for fMRI hyperacuity (biased sampling by averaging within each voxel's boundaries; Kamitani and Tong, 2005) will only produce very weak sensitivity to fine-grained pattern information, and (c) that an alternative mechanism (voxel as complex spatiotemporal filter) is physiologically more accurate and promises stronger sensitivity to fine-grained pattern information: We know that each voxel samples the neuronal activity pattern through a unique fine-grained structure of venous vessels that supply its blood oxygen level-dependent signal. At the simplest level, the drainage domain of a venous vessel may sample the neuronal pattern with a selectivity bias (Gardner, 2009; Shmuel et al., 2009). Beyond biased drainage domains, we illustrate with a simple simulation how temporal properties of the hemodynamics (e.g., the speed of the blood in the capillary bed) can shape spatial properties of a voxel's filter (e.g., how finely structured it is). This

  2. Different patterns of confabulation.

    Science.gov (United States)

    Dalla Barba, G

    1993-12-01

    In this study we investigated the amnesic-confabulatory condition of two patients, M.B. and S.D., exhibiting different patterns of confabulation. Neuropsychological examination showed in M.B. a normal intellectual efficiency and a selective deficit of episodic memory, whereas S.D. was impaired in tests of intellectual efficiency, episodic memory, semantic knowledge and frontal functions. The relation of confabulation to retrieval conditions and the degree of impairment of the semantic memory system was investigated with a set of questions involving the retrieval of various kinds of information. In M.B. confabulation was restricted to episodic memory tasks, whereas in S.D. it also affected the retrieval of semantic information. S.D.'s confabulatory reports were 'semantically anomalous', whereas the semantic structure of M.B.'s confabulations was appropriate. Further investigation using the encoding specificity paradigm showed an interaction of encoding/retrieval conditions in M.B. but not in S.D. This pattern of results is discussed in terms of a different level of disruption of processes that normally monitor the retrieval of information. It is further argued that the confabulation content must be considered in terms of its semantic structure and relies on the level of integrity of semantic knowledge.

  3. Patterns of Negotiation

    Science.gov (United States)

    Sood, Suresh; Pattinson, Hugh

    Traditionally, face-to-face negotiations in the real world have not been looked at as a complex systems interaction of actors resulting in a dynamic and potentially emergent system. If indeed negotiations are an outcome of a dynamic interaction of simpler behavior just as with a complex system, we should be able to see the patterns contributing to the complexities of a negotiation under study. This paper and the supporting research sets out to show B2B (business-to-business) negotiations as complex systems of interacting actors exhibiting dynamic and emergent behavior. This paper discusses the exploratory research based on negotiation simulations in which a large number of business students participate as buyers and sellers. The student interactions are captured on video and a purpose built research method attempts to look for patterns of interactions between actors using visualization techniques traditionally reserved to observe the algorithmic complexity of complex systems. Students are videoed negotiating with partners. Each video is tagged according to a recognized classification and coding scheme for negotiations. The classification relates to the phases through which any particular negotiation might pass, such as laughter, aggression, compromise, and so forth — through some 30 possible categories. Were negotiations more or less successful if they progressed through the categories in different ways? Furthermore, does the data depict emergent pathway segments considered to be more or less successful? This focus on emergence within the data provides further strong support for face-to-face (F2F) negotiations to be construed as complex systems.

  4. Archetypes as action patterns.

    Science.gov (United States)

    Hogenson, George B

    2009-06-01

    The discovery of mirror neurons by researchers at the University of Parma promises to radically alter our understanding of fundamental cognitive and affective states. This paper explores the relationship of mirror neurons to Jung's theory of archetypes and proposes that archetypes may be viewed as elementary action patterns. The paper begins with a review of a proposed interpretation of the fainting spells of S. Freud in his relationship with Jung as an example of an action pattern that also defines an archetypal image. The challenge that mirror neurons present to traditional views in analytical psychology and psychoanalysis, however, is that they operate without recourse to a cognitive processing element. This is a position that is gaining increasing acceptance in other fields as well. The paper therefore reviews the most recent claims made by the Boston Process of Change Study Group as well as conclusions drawn from dynamic systems views of development and theoretical robotics to underline the conclusion that unconscious agency is not a requirement for coherent action. It concludes with the suggestion that this entire body of research may lead to the conclusion that the dynamic unconscious is an unnecessary hypothesis in psychoanalysis and analytical psychology.

  5. Patterns and Costs of Crime.

    Science.gov (United States)

    Lincoln, Alan Jay

    1984-01-01

    Presents results of the Library Crime Research Project, a three-year study of crime and disruption patterns in public libraries in all 50 states. Patterns of crime, costs of crime (direct, indirect), losses due to crime, patterns of security use, and effects of victimization are covered. Three references are listed. (EJS)

  6. Pattern Based Graph Generator

    CERN Document Server

    Shuai, Hong-Han; Yu, Philip S; Shen, Chih-Ya; Chen, Ming-Syan

    2013-01-01

    The importance of graph mining has been widely recognized thanks to a large variety of applications in many areas, while real datasets always play important roles to examine the solution quality and efficiency of a graph mining algorithm. Nevertheless, the size of a real dataset is usually fixed and constrained according to the available resources, such as the efforts to crawl an on-line social network. In this case, employing a synthetic graph generator is a possible way to generate a massive graph (e.g., billions nodes) for evaluating the scalability of an algorithm, and current popular statistical graph generators are properly designed to maintain statistical metrics such as total node degree, degree distribution, diameter, and clustering coefficient of the original social graphs. Nevertheless, in addition to the above metrics, recent studies on graph mining point out that graph frequent patterns are also important to provide useful implications for the corresponding social networking applications, but thi...

  7. Female pattern hair loss

    Directory of Open Access Journals (Sweden)

    Archana Singal

    2013-01-01

    Full Text Available Female pattern hair loss (FPHL is a common cause of hair loss in women characterized by diffuse reduction in hair density over the crown and frontal scalp with retention of the frontal hairline. Its prevalence increases with advancing age and is associated with significant psychological morbidity. The pathophysiology of FPHL is still not completely understood and seems to be multifactorial. Although androgens have been implicated, the involvement of androgen-independent mechanisms is evident from frequent lack of clinical or biochemical markers of hyperandrogenism in affected women. The role of genetic polymorphisms involving the androgen and estrogen receptors is being increasingly recognized in its causation and predicting treatment response to anti-androgens. There are different clinical patterns and classifications of FPHL, knowledge of which facilitates patient management and research. Chronic telogen effluvium remains as the most important differential diagnosis. Thorough history, clinical examination, and evaluation are essential to confirm diagnosis. Patients with clinical signs of androgen excess require assessment of biochemical parameters and imaging studies. It is prudent to screen the patients for metabolic syndrome and cardiovascular risk factors. The treatment comprises medical and/or surgical modalities. Medical treatment should be initiated early as it effectively arrests hair loss progression rather than stimulating regrowth. Minoxidil continues to be the first line therapy whereas anti-androgens form the second line of treatment. The progressive nature of FPHL mandates long-term treatment for sustained effect. Medical therapy may be supplemented with cosmetic concealment in those desirous of greater hair density. Surgery may be worthwhile in some carefully selected patients.

  8. Information Demand Pattern for Teams

    Directory of Open Access Journals (Sweden)

    Dirk Stamer

    2016-04-01

    Full Text Available Modern organizations face the challenge of having to manage an increasing amount of information. The resulting information overload leads more and more to problems in decision making with potentially negative economic consequences. Decision-makers and knowledge intensive workers are especially affected. To address this problem, information demand patterns were proposed which capture organizational knowledge about the information demand of single roles. This work extends the concept of information demand patterns from single roles to teams. Using the knowledge intensive field of project management, the paper shows how to apply the concept of information demand patterns for a whole team. The contributions of this work are (1 the methodical approach to develop information demand patterns for teams, (2 an actual information demand pattern for a steering committee in the context of project management, (3 reflections on the differences between role patterns and team patterns.

  9. Personal continuous route pattern mining

    Institute of Scientific and Technical Information of China (English)

    Qian YE; Ling CHEN; Gen-cai CHEN

    2009-01-01

    In the daily life, people often repeat regular routes in certain periods. In this paper, a mining system is developed to find the continuous route patterns of personal past trips. In order to count the diversity of personal moving status, the mining system employs the adaptive GPS data recording and five data filters to guarantee the clean trips data. The mining system uses a client/server architecture to protect personal privacy and to reduce the computational load. The server conducts the main mining procedure but with insufficient information to recover real personal routes. In order to improve the scalability of sequential pattern mining, a novel pattern mining algorithm, continuous route pattern mining (CRPM), is proposed. This algorithm can tolerate the different disturbances in real routes and extract the frequent patterns. Experimental results based on nine persons' trips show that CRPM can extract more than two times longer route patterns than the traditional route pattern mining algorithms.

  10. Varianish: Jamming with Pattern Repetition

    Directory of Open Access Journals (Sweden)

    Jort Band

    2014-10-01

    Full Text Available In music, patterns and pattern repetition are often regarded as a machine-like task, indeed often delegated to drum Machines and sequencers. Nevertheless, human players add subtle differences and variations to repeated patterns that are musically interesting and often unique. Especially when looking at minimal music, pattern repetitions create hypnotic effects and the human mind blends out the actual pattern to focus on variation and tiny differences over time. Varianish is a musical instrument that aims at turning this phenomenon into a new musical experience for musician and audience: Musical pattern repetitions are found in live music and Varianish generates additional (musical output accordingly that adds substantially to the overall musical expression. Apart from the theory behind the pattern finding and matching and the conceptual design, a demonstrator implementation of Varianish is presented and evaluated.

  11. From Sequential Pattern Mining to Structured Pattern Mining:A Pattern-Growth Approach

    Institute of Scientific and Technical Information of China (English)

    Jia-Wei Han; Jian Pei; Xi-Feng Yan

    2004-01-01

    Sequential pattern mining is an important data mining problem with broad applications. However,it is also a challenging problem since the mining may have to generate or examine a combinatorially explosive number of intermediate subsequences. Recent studies have developed two major classes of sequential pattern mining methods: (1) a candidate generation-and-test approach, represented by (i) GSP, a horizontal format-based sequential pattern mining method, and (ii) SPADE, a vertical format-based method; and (2) a pattern-growth method, represented by PrefixSpan and its further extensions, such as gSpan for mining structured patterns. In this study, we perform a systematic introduction and presentation of the pattern-growth methodology and study its principles and extensions. We first introduce two interesting pattern-growth algorithms, FreeSpan and PrefixSpan, for efficient sequential pattern mining. Then we introduce gSpan for mining structured patterns using the same methodology. Their relative performance in large databases is presented and analyzed. Several extensions of these methods are also discussed in the paper, including mining multi-level, multi-dimensional patterns and mining constraint-based patterns.

  12. From Sequential Pattern Mining to Structured Pattern Mining: A Pattern-Growth Approach

    Institute of Scientific and Technical Information of China (English)

    Jia-WeiHan; JianPei; Xi-FengYan

    2004-01-01

    Sequential pattern mining is an important data mining problem with broad applications. However, it is also a challenging problem since the mining may have to generate or examine a combinatorially explosive number of intermediate subsequences. Recent studies have developed two major classes of sequential pattern mining methods: (1) a candidate generation-and-test approach, represented by (i) GSP, a horizontal format-based sequential pattern mining method, and (ii) SPADE, a vertical format-based method; and (2) a pattern-growth method, represented by PrefixSpan and its further extensions, such as gSpan for mining structured patterns. In this study, we perform a systematic introduction and presentation of the pattern-growth methodology and study its principles and extensions. We first introduce two interesting pattern-growth algorithms, FreeSpan and PrefixSpan, for efficient sequential pattern mining. Then we introduce gSpan for mining structured patterns using the same methodology. Their relative performance in large databases is presented and analyzed. Several extensions of these methods are also discussed in the paper, including mining multi-level, multi-dimensional patterns and mining constraint-based patterns.

  13. Central pattern generation underlying Limulus rhythmic behavior patterns

    Directory of Open Access Journals (Sweden)

    Gordon A. Wyse

    2010-10-01

    Full Text Available Many behavioral activities of the horseshoe crab Limulus are rhythmic, and most of these are produced in large part by central pattern generators within the CNS. The chain of opisthosomal (‘abdominal’ ganglia controls gill movements of ventilation and gill cleaning, and the prosomal ring of fused ganglia (brain and segmental ‘thoracic’ ganglia controls generation of feeding and locomotor movements of the legs. Both the opisthosomal CNS and the prosomal CNS can generate behaviorally appropriate patterns of motor output in isolation, without movements or sensory input. Preparations of the isolated opisthosomal CNS generate rhythmic output patterns of motor activity characterized as fictive ventilatory and gill cleaning rhythms. Moreover, CNS preparations also express longer-term patterns, such as intermittent ventilation or sequential bouts of ventilation and gill cleaning. Such longer-term patterns are commonly observed in intact animals. The isolated prosomal CNS does not spontaneously generate the activity patterns characteristic of walking, swimming, and feeding. However, perfusion of octopamine in the isolated prosomal CNS activates central pattern generators underlying rhythmic chewing movements, and injection of octopamine into intact Limulus promotes the chewing pattern of feeding, whether or not food is presented. Our understanding of the ability of neuromodulators such as octopamine to elicit or alter central motor programs may help to clarify the central neural circuits of pattern generation that produce and coordinate these rhythmic behaviors [Current Zoology 56 (5: 537–549, 2010].

  14. Patterns in the mind

    Directory of Open Access Journals (Sweden)

    Acosta Alejandro

    1999-06-01

    Full Text Available

     A mediados de la década de los noventa, el lingüista estadounidense Ray Jackendoff, meditando acerca de la situación de los avances en su campo de trabajo, publicó el libro Patterns in the Mind con el objetivo de poner al alcance del público no especializado los avances de la psicología cognitiva a partir de los postulados básicos de la revolución lingüística y cognitiva que
    floreció gracias a los trabajos del también lingüista norteamericano Noam Chomsky, a finales de la década de los cincuenta y principios de la de los sesenta. Su presencia en el desarrollo de esta nueva etapa del estudio del lenguaje y sus intereses en las nuevas teorías psicológicas 10 ubicaron en un marco teórico que comprende postulados acerca de la organización modular de las estructuras y procesos mentales, el innatismo de este tipo de organización y la existencia de una serie de patrones que rigen la construcción de gramáticas mentalesinconscientes para diversos dominios de la naturaleza humana.

  15. Aggression patterns and speciation.

    Science.gov (United States)

    Nevo, E; Naftali, G; Guttman, R

    1975-01-01

    The evolutionary significance of interspecific aggression as a factor in speciation was tested among three chromosome forms of the actively speciating fossorial rodent Spalax ehrenbergi in Israel. Laboratory experiments testing intra- and interspecific aggression were conducted on 48 adult animals from 10 populations comprising three chromosome forms with 2n = 52, 58, and 60. Twelve agonistic, motivational-conflict, and territorial behavioral variables were recorded during 72 combats involving homo- and heter-ogametic encounters between opponents. Analysis of the data matrix was carried out by the nonmetric multivariate Smallest Space Analysis (SSA-II). The results indicate that (a) aggression patterns, involving agonistic conflict and territorial variables, are higher in heterogametic encounters than in homogametic ones; and (b) aggression is higher between contiguous chromosome forms (2n = 58-60, and 2n = 52-58) than between noncontiguous ones (2n = 52-60). Both a and b suggest that high interspecific aggression appears to be adaptively selected at final stages of speciation in mole rats as a premating isolating mechanism which reinforces species identification and establishes parapatric distributions between the evolving species. PMID:1059109

  16. Brugada ECG patterns in athletes.

    Science.gov (United States)

    Chung, Eugene H

    2015-01-01

    Brugada syndrome is responsible for up to 4% of all sudden cardiac deaths worldwide and up to 20% of sudden cardiac deaths in patients with structurally normal hearts. Heterogeneity of repolarization and depolarization, particularly over the right ventricle and the outflow tract, is responsible for the arrhythmogenic substrate. The coved Type I ECG pattern is considered diagnostic of the syndrome but its prevalence is very low. Distinguishing between a saddle back Type 2 Brugada pattern and one of many "Brugada-like" patterns presents challenges especially in athletes. A number of criteria have been proposed to assess Brugada ECG patterns. Proper precordial ECG lead placement is paramount. This paper reviews Brugada syndrome, Brugada ECG patterns, and recently proposed criteria. Recommendations for evaluating a Brugada ECG pattern are provided.

  17. Parental dietary patterns and social determinants of children's dietary patterns

    Directory of Open Access Journals (Sweden)

    Rosana SALLES-COSTA

    Full Text Available ABSTRACT Objective To identify dietary patterns in children up to thirty months of age and verify whether they are associated with parental dietary patterns, and socioeconomic and demographic characteristics. Methods This is a cross-sectional study with baseline data from a population-based study composed of 1,085 households from a representative sample of a metropolitan region in Rio de Janeiro, Brazil. The children's food intake was evaluated by two 24-hour recalls, and the dietary patterns were identified by principal component analysis stratified into two groups according to the children's age: 6 to 17 months; and 18 to 30 months. The explanatory variables collected by a structured questionnaire were socioeconomic and demographic characteristics, age at introduction of complementary foods, and parental dietary pattern. A Food Frequency Questionnaire was administered to assess parental dietary pattern, which was determined by principal component analysis. Multivariate linear regression estimated the effect of each explanatory variable on the children's dietary patterns. Results Three dietary patterns were identified in children aged 6-17 months (basic-mixed; mixed-plus; and milk-flours and two dietary patterns were identified in children aged 18-30 months: basic-mixed and mixed-plus. Multivariate linear regression showed that complementary feeding (b=0.108; p=0.004 was positively associated with the basic-mixed dietary pattern, and family income (b=0.002; p£0.01, with the mixed-plus dietary pattern. A negative association was found between the traditional parental dietary pattern and children's mixed-plus pattern in children aged 6-17 months (b=0.152; p=0.006 and in children aged 18-30 months (b=0.152; p=0.016. In children aged up to 18 months, parental education level (b=0.368; p£0.01 was positively associated with the mixed-plus dietary pattern. Conclusion Family income, parental education level, and parental dietary patterns are

  18. Review og pattern matching approaches

    DEFF Research Database (Denmark)

    Manfaat, D.; Duffy, Alex; Lee, B. S.

    1996-01-01

    This paper presents a review of pattern matching techniques. The application areas for pattern matching are extensive, ranging from CAD systems to chemical analysis and from manufacturing to image processing. Published techniques and methods are classified and assessed within the context of three...... key issues: pattern classes, similiarity types and mathing methods. It has been shown that the techniques and approaches are as diverse and varied as the applications....

  19. Pattern Recognition Theory of Mind

    OpenAIRE

    2009-01-01

    I propose that pattern recognition, memorization and processing are key concepts that can be a principle set for the theoretical modeling of the mind function. Most of the questions about the mind functioning can be answered by a descriptive modeling and definitions from these principles. An understandable consciousness definition can be drawn based on the assumption that a pattern recognition system can recognize its own patterns of activity. The principles, descriptive modeling and definiti...

  20. Geochemical Characteristics of Rare Earth Elements in Sewage Discharge Channels of Tianjin

    Institute of Scientific and Technical Information of China (English)

    王立军; 梁涛; 丁力强; 张朝生; 李国胜; 闫欣; 王秀丽

    2003-01-01

    The geochemical features of rare earth elements (REEs) in the North and South sewage discharge channels of Tianjin were studied. The results show that concentrations of dissolved REEs in water of the sewage discharge channels are very low, while concentrations of Eu and heavy REEs are higher than those in natural rivers. Concentrations of REEs in unfiltered water are high and they mainly resided on suspended matter. Distribution patterns of the dissolved and susp ended light REEs vary reversely with the atomic number. Concentrations of REEs in the sediments and suspended matter are lower than those in natural rivers, and concentrations of REEs in the suspended matter are much lower than those in the sediments. Distribution patterns of REEs in sediments and suspended matter were similar with light REE enrichment and positive Eu-anomaly. This distributi on pattern is different from those of natural rivers. The differences may cause by the large amount of organic pollutants in sewage.

  1. Lithographically patterned nanowire electrodeposition

    Science.gov (United States)

    Xiang, Chengxiang

    Lithographically patterned nanowire electrodeposition (LPNE) is a new method for fabricating polycrystalline metal nanowires using electrodeposition. In LPNE, a sacrificial metal (M1 = silver or nickel) layer, 5 - 100 nm in thickness, is first vapor deposited onto a glass, oxidized silicon, or Kapton polymer film. A photoresist (PR) layer is then deposited, photopatterned, and the exposed Ag or Ni is removed by wet etching. The etching duration is adjusted to produce an undercut ≈300 nm in width at the edges of the exposed PR. This undercut produces a horizontal trench with a precisely defined height equal to the thickness of theM1 layer. Within this trench, a nanowire of metal M2 is electrodeposited (M2 = gold, platinum, palladium, or bismuth). Finally the PR layer and M1 layer are removed. The nanowire height and width can be independently controlled down to minimum dimensions of 5 nm (h) and 11 nm (w), for example, in the case of platinum. These nanowires can be 1 cm in total length. We measure the temperature-dependent resistance of 100 um sections of Au and Pd wires in order to estimate an electrical grain size for comparison with measurements by X-ray diffraction and transmission electron microscopy. Nanowire arrays can be postpatterned to produce two-dimensional arrays of nanorods. Nanowire patterns can also be overlaid one on top of another by repeating the LPNE process twice in succession to produce, for example, arrays of low-impedance, nanowirenanowire junctions. The resistance, R, of single gold nanowires was measured in situ during electrooxidation in aqueous 0.10 M sulfuric acid. Electrooxidation caused the formation of a gold oxide that is approximately 0.8 monolayers (ML) in thickness at +1.1 V vs saturated mercurous sulfate reference electrode (MSE) based upon coulometry and ex situ X-ray photoelectron spectroscopic analysis. As the gold nanowires were electrooxidized, R increased by an amount that depended on the wire thickness, ranging from

  2. Pattern Avoidance in Ternary Trees

    CERN Document Server

    Gabriel, Nathan; Pudwell, Lara; Tay, Samuel

    2011-01-01

    This paper considers the enumeration of ternary trees (i.e. rooted ordered trees in which each vertex has 0 or 3 children) avoiding a contiguous ternary tree pattern. We begin by finding recurrence relations for several simple tree patterns; then, for more complex trees, we compute generating functions by extending a known algorithm for pattern-avoiding binary trees. Next, we present an alternate one-dimensional notation for trees which we use to find bijections that explain why certain pairs of tree patterns yield the same avoidance generating function. Finally, we compare our bijections to known "replacement rules" for binary trees and generalize these bijections to a larger class of trees.

  3. PHP Objects, Patterns, and Practice

    CERN Document Server

    Zandstra, Matt

    2010-01-01

    This book takes you beyond the PHP basics to the enterprise development practices used by professional programmers. Updated for PHP 5.3 with new sections on closures, namespaces, and continuous integration, this edition will teach you about object features such as abstract classes, reflection, interfaces, and error handling. You'll also discover object tools to help you learn more about your classes, objects, and methods. Then you'll move into design patterns and the principles that make patterns powerful. You'll learn both classic design patterns and enterprise and database patterns with easy

  4. Professional Java EE design patterns

    CERN Document Server

    Yener, Murat

    2014-01-01

    Master Java EE design pattern implementation to improve your design skills and your application's architecture Professional Java EE Design Patterns is the perfect companion for anyone who wants to work more effectively with Java EE, and the only resource that covers both the theory and application of design patterns in solving real-world problems. The authors guide readers through both the fundamental and advanced features of Java EE 7, presenting patterns throughout, and demonstrating how they are used in day-to-day problem solving. As the most popular programming language in community-dri

  5. Chemical patterning in biointerface science

    Directory of Open Access Journals (Sweden)

    Ryosuke Ogaki

    2010-04-01

    Full Text Available Patterning of surfaces with different chemistries provides novel insights into how proteins, cells and tissues interact with materials. New materials, and the properties that their surfaces impart, are highly desirable for the next generation of implants, regenerative medicine and tissue engineering devices, and biosensors and drug delivery devices for disease diagnosis and treatment. Patterning is thus seen as a key technology driver for these materials. We provide an overview of state-of-the-art fabrication tools for creating chemical patterns over length scales ranging from millimeters to micrometers to nanometers. The importance of highly sensitive surface analytical tools in the development of new chemically patterned surfaces is highlighted.

  6. Dietary Patterns: Challenges and Opportunities in Dietary Patterns Research

    Science.gov (United States)

    In recent years, increasing numbers of researchers have used dietary patterns to characterize the population’s diet and to examine associations between diet and disease outcomes. Many methods, primarily data-driven and index-based approaches, are available for characterizing dietary patterns in a p...

  7. State of rare earth elements in different environmental components in mining areas of China.

    Science.gov (United States)

    Liang, Tao; Li, Kexin; Wang, Lingqing

    2014-03-01

    China has relatively abundant rare earth elements (REEs) reserves and will continue to be one of the major producers of REEs for the world market in the foreseeable future. However, due to the large scale of mining and refining activities, large amounts of REEs have been released to the surrounding environment and caused harmful effects on local residents. This paper summarizes the data about the contents and translocation of REEs in soils, waters, atmosphere, and plants in REE mining areas of China and discusses the characteristics of their forms, distribution, fractionation, and influencing factors. Obviously high concentrations of REEs with active and bioavailable forms are observed in all environmental media. The mobility and bioavailability of REEs are enhanced. The distribution patterns of REEs in soils and water bodies are all in line with their parent rocks. Significant fractionation phenomenon among individual members of REEs was found in soil-plant systems. However, limited knowledge was available for REEs in atmosphere. More studies focusing on the behavior of REEs in ambient air of REE mining areas in China are highly suggested. In addition, systematic study on the translocation and circulation of REEs in various media in REEs mining areas and their health risk assessment should be carried out. Standard analytical methods of REEs in environments need to be established, and more specific guideline values of REEs in foods should also be developed.

  8. Patterning nanocrystals using DNA

    Energy Technology Data Exchange (ETDEWEB)

    Williams, Shara Carol

    2003-09-01

    One of the goals of nanotechnology is to enable programmed self-assembly of patterns made of various materials with nanometer-sized control. This dissertation describes the results of experiments templating arrangements of gold and semiconductor nanocrystals using 2'-deoxyribonucleic acid (DNA). Previously, simple DNA-templated linear arrangements of two and three nanocrystals structures have been made.[1] Here, we have sought to assemble larger and more complex nanostructures. Gold-DNA conjugates with 50 to 100 bases self-assembled into planned arrangements using strands of DNA containing complementary base sequences. We used two methods to increase the complexity of the arrangements: using branched synthetic doublers within the DNA covalent backbone to create discrete nanocrystal groupings, and incorporating the nanocrystals into a previously developed DNA lattice structure [2][3] that self-assembles from tiles made of DNA double-crossover molecules to create ordered nanoparticle arrays. In the first project, the introduction of a covalently-branched synthetic doubler reagent into the backbone of DNA strands created a branched DNA ''trimer.'' This DNA trimer templated various structures that contained groupings of three and four gold nanoparticles, giving promising, but inconclusive transmission electron microscopy (TEM) results. Due to the presence of a variety of possible structures in the reaction mixtures, and due to the difficulty of isolating the desired structures, the TEM and gel electrophoresis results for larger structures having four particles, and for structures containing both 5 and 10 nm gold nanoparticles were inconclusive. Better results may come from using optical detection methods, or from improved sample preparation. In the second project, we worked toward making two-dimensional ordered arrays of nanocrystals. We replicated and improved upon previous results for making DNA lattices, increasing the size of the lattices

  9. Menstrual cycle pattern and fertility

    DEFF Research Database (Denmark)

    Kolstad, Henrik A.; Bonde, Jens Peter; Hjøllund, Niels Henrik;

    1999-01-01

    To characterize how the menstrual cycle pattern relates to fertility regardless of potential biases caused by inappropriate coital timing during the menstrual cycle or early embryonal loss.......To characterize how the menstrual cycle pattern relates to fertility regardless of potential biases caused by inappropriate coital timing during the menstrual cycle or early embryonal loss....

  10. Injury Patterns in Youth Sports.

    Science.gov (United States)

    Goldberg, Barry

    1989-01-01

    Presents statistics on injury patterns in youth sports, recommending that physicians who care for young athletes understand the kinds of injuries likely to be sustained. Awareness of injury patterns helps medical professionals identify variables associated with injury, anticipate or prevent injuries, plan medical coverage, and compare individual…

  11. Research applications of ecosystem patterns

    Science.gov (United States)

    Robert G. Bailey

    2009-01-01

    This article discusses the origins of natural ecosystem patterns from global to local scales. It describes how understanding these patterns can help scientists and managers in two ways. First, the local systems are shown within the context of larger systems. This perspective can be applied in assessing the connections between action at one scale and effect at another,...

  12. Hand aperture patterns in prehension

    NARCIS (Netherlands)

    Bongers, Raoul M.; Zaal, Frank T. J. M.; Jeannerod, Marc

    2012-01-01

    Although variations in the standard prehensile pattern can be found in the literature, these alternative patterns have never been studied systematically. This was the goal of the current paper. Ten participants picked up objects with a pincer grip. Objects (3, 5, or 7 cm in diameter) were placed at

  13. Growing Patterns: Seeing beyond Counting

    Science.gov (United States)

    Markworth, Kimberly A.

    2012-01-01

    Over the past two decades, mathematical patterns have been acknowledged as important early components of children's development of algebraic reasoning (NCTM 2000). In particular, growing patterns have attracted significant attention as a context that helps students develop an understanding of functional relationships (Lee and Freiman 2006; Moss et…

  14. Patterns of Personal Learning Environments

    Science.gov (United States)

    Wilson, Scott

    2008-01-01

    The use of design patterns is now well established as an approach within the field of software systems as well as within the field of architecture. An initial effort was made to harness patterns as a tool for elaborating the design of the elements of personal learning environments as part of the University of Bolton's Personal Learning Environment…

  15. Linear Patterns and Their Equations

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    <正>A linear pattern,the points plotted all lie on the same straight line.In this section we will be looking further into such linear patterns. In this figure,by plotting the points B to F and joining them,

  16. Pigments, patterns, and fish behavior.

    Science.gov (United States)

    Price, Anna C; Weadick, Cameron J; Shim, Janet; Rodd, F Helen

    2008-12-01

    Color patterns in fish are often multicomponent signals, composed of pigment-based and structural color patches that can be used to communicate within species, in both inter- and intrasexual interactions, and between species. In this review, we discuss some of the roles played by pigment-based elements of color pattern. We begin by discussing general forms of coloration, classifying them by appearance (e.g., cryptic vs. conspicuous) and apparent function (e.g., conspicuous coloration and mating displays, stripes and cooperation, and bars and aggression). We then briefly discuss the roles pigments play in the perception of these color patterns via their presence in the eye. In the last section, we look at the relative importance of carotenoid versus melanic coloration in situations where honest signals to potential rivals and potential mates might be required. In this survey, we have highlighted some recent research, especially studies that consider both the physiological and behavioral processes underlying the evolution and expression of pigment-based color patterns in fish. The nature of pigmented color patterns depends not just on the dynamics of pattern development and physiological regulation, but also on the behavioral roles played by these patterns, both now and in the past. As such, advances in particular fields of study on pigment patterns (physiology, developmental biology, behavioral ecology, evolutionary biology, etc.) will increasingly depend on insights from other fields.

  17. Dynamical electron backscatter diffraction patterns. Part I: pattern simulations.

    Science.gov (United States)

    Callahan, Patrick G; De Graef, Marc

    2013-10-01

    A new approach for the simulation of dynamic electron backscatter diffraction (EBSD) patterns is introduced. The computational approach merges deterministic dynamic electron-scattering computations based on Bloch waves with a stochastic Monte Carlo (MC) simulation of the energy, depth, and directional distributions of the backscattered electrons (BSEs). An efficient numerical scheme is introduced, based on a modified Lambert projection, for the computation of the scintillator electron count as a function of the position and orientation of the EBSD detector; the approach allows for the rapid computation of an individual EBSD pattern by bi-linear interpolation of a master EBSD pattern. The master pattern stores the BSE yield as a function of the electron exit direction and exit energy and is used along with weight factors extracted from the MC simulation to obtain energy-weighted simulated EBSD patterns. Example simulations for nickel yield realistic patterns and energy-dependent trends in pattern blurring versus filter window energies are in agreement with experimental energy-filtered EBSD observations reported in the literature.

  18. Patterning and templating for nanoelectronics.

    Science.gov (United States)

    Galatsis, Kosmas; Wang, Kang L; Ozkan, Mihri; Ozkan, Cengiz S; Huang, Yu; Chang, Jane P; Monbouquette, Harold G; Chen, Yong; Nealey, Paul; Botros, Youssry

    2010-02-09

    The semiconductor industry will soon be launching 32 nm complementary metal oxide semiconductor (CMOS) technology node using 193 nm lithography patterning technology to fabricate microprocessors with more than 2 billion transistors. To ensure the survival of Moore's law, alternative patterning techniques that offer advantages beyond conventional top-down patterning are aggressively being explored. It is evident that most alternative patterning techniques may not offer compelling advantages to succeed conventional top-down lithography for silicon integrated circuits, but alternative approaches may well indeed offer functional advantages in realising next-generation information processing nanoarchitectures such as those based on cellular, bioinsipired, magnetic dot logic, and crossbar schemes. This paper highlights and evaluates some patterning methods from the Center on Functional Engineered Nano Architectonics in Los Angeles and discusses key benchmarking criteria with respect to CMOS scaling.

  19. Method of patterning an aerogel

    Science.gov (United States)

    Reed, Scott T.

    2012-07-24

    A method for producing a pattern in an aerogel disposed as a coating on a substrate comprises exposing the aerogel coating to the vapors of a hydrophobic silane compound, masking the aerogel coating with a shadow photomask and irradiating the aerogel coating with ultraviolet (UV) irradiation. The exposure to UV through the shadow mask creates a pattern of hydrophobic and hydrophilic regions in the aerogel coating. Etching away the hydrophilic regions of the aerogel coating, preferably with a 1 molar solution of sodium hydroxide, leaves the unwetted and unetched hydrophobic regions of the aerogel layer on the substrate, replicating the pattern of the photomask. The hydrophobic aerogel pattern can be further exposed to UV irradiation if desired, to create a hydrophilic aerogel pattern.

  20. Mobile Design Pattern Gallery UI Patterns for Mobile Applications

    CERN Document Server

    Neil, Theresa

    2012-01-01

    When you're under pressure to produce a well designed, easy-to-navigate mobile app, there's no time to reinvent the wheel. This concise book provides a handy reference to 70 mobile app design patterns, illustrated by more than 400 screenshots from current iOS, Android, BlackBerry, WebOS, Windows Mobile, and Symbian apps. User experience professional Theresa Neil (Designing Web Interfaces) walks you through design patterns in 10 separate categories, including anti-patterns. Whether you're designing a simple iPhone application or one that's meant to work for every popular mobile OS on the mark

  1. Security patterns in practice designing secure architectures using software patterns

    CERN Document Server

    Fernandez-Buglioni, Eduardo

    2013-01-01

    Learn to combine security theory and code to produce secure systems Security is clearly a crucial issue to consider during the design and implementation of any distributed software architecture. Security patterns are increasingly being used by developers who take security into serious consideration from the creation of their work. Written by the authority on security patterns, this unique book examines the structure and purpose of security patterns, illustrating their use with the help of detailed implementation advice, numerous code samples, and descriptions in UML. Provides

  2. Impact glass spherules in the Chicxulub K-Pg event bed at Beloc, Haiti: Alteration patterns

    Science.gov (United States)

    Ritter, Xenia; Deutsch, Alexander; Berndt, Jasper; Robin, Eric

    2015-03-01

    We have investigated six impact glass spherules from the K-Pg event bed at Beloc, Haiti, using optical and electron microscopy, electron microprobe and in situ laser ablation-mass spectrometry (LA-ICP-MS; 37 trace elements, spot size 90-35 μm), in order to understand geochemical changes during alteration. The mm-sized glass spherules are partly or totally altered to smectite, but original textural features are preserved. The average trace-element composition of glass matches that one of the upper continental crust. Hints for a "meteoritic component" are lacking (Ni/Cr < 1.3 Pt below detection limit). Compared to this fresh glass, smectites are strongly depleted in trace elements, except for Li, Sc, V, Ni, Ga, Ge, and Ba. The chondrite-normalized REE distribution patterns are flat with subchondritic abundances, related to their very low degree of crystallinity. We observe a positive Eu and a strong negative Ce anomaly; the latter is explained by formation of an organic Ce4+-complex, soluble under reducing conditions. Zr/Hf of glasses and smectites is chondritic to superchondritic (35-40), whereas Nb/Ta in smectite is subchondritic (5-12) compared to Nb/Ta in the glass (~14-18). The low Nb/Ta is due to the low Nb concentrations in the smectite. Using in situ techniques with high spatial resolution, we have documented for the first time the significant changes in diagnostic elemental ratios during alteration of glass spherules. This has to be taken into account in the interpretation of geochemical data of not only impact materials but also volcanic glass, especially if bulk rock methods are used.

  3. Pattern Classification in Kampo Medicine

    Directory of Open Access Journals (Sweden)

    S. Yakubo

    2014-01-01

    Full Text Available Pattern classification is very unique in traditional medicine. Kampo medical patterns have transformed over time during Japan’s history. In the 17th to 18th centuries, Japanese doctors advocated elimination of the Ming medical theory and followed the basic concepts put forth by Shang Han Lun and Jin Gui Yao Lue in the later Han dynasty (25–220 AD. The physician Todo Yoshimasu (1702–1773 emphasized that an appropriate treatment could be administered if a set of patterns could be identified. This principle is still referred to as “matching of pattern and formula” and is the basic concept underlying Kampo medicine today. In 1868, the Meiji restoration occurred, and the new government changed its policies to follow that of the European countries, adopting only Western medicine. Physicians trained in Western medicine played an important role in the revival of Kampo medicine, modernizing Kampo patterns to avoid confusion with Western biomedical terminology. In order to understand the Japanese version of traditional disorders and patterns, background information on the history of Kampo and its role in the current health care system in Japan is important. In this paper we overviewed the formation of Kampo patterns.

  4. Analysis Of Overlay Distortion Patterns

    Science.gov (United States)

    Armitage, John D.; Kirk, Joseph P.

    1988-01-01

    A comprehensive geometrical approach is presented for the least-squares analysis of overlay distortion patterns into useful, physically meaningful systematic distortion subpatterns and an essentially non-systematic residue. A scheme of generally useful distortion sub-patterns is presented in graphic and algorithmic form; some of these sub-patterns are additions to those already in widespread use. A graphic and geometric approach is emphasized rather than an algebraic or statistical approach, and an example illustrates the value in utilizing the pattern-detecting ability of the eye-brain system. The conditions are described under which different distortion sub-patterns may interact, possibly leading to misleading or erroneous conclusions about the types and amounts of different distortions present. Examples of typical interaction situations are given, and recommendations are made for analytic procedures to avoid misinterpretation. It is noted that the lower-order distortion patterns preserve straight-line linearity, but that higher-order distortion may result in straight lines becoming curved. The principle of least-squares analysis is outlined and a simple polynomial data-fitting example is used to illustrate the method. Algorithms are presented for least-squares distortion analysis of overlay patterns, and an APL2 program is given to show how this may easily be implemented on a digital computer. The appendix extends the treatment to cases where small-angle approximation is not permissible.

  5. Pattern Discovery Using Association Rules

    Directory of Open Access Journals (Sweden)

    Ms Kiruthika M,

    2011-12-01

    Full Text Available The explosive growth of Internet has given rise to many websites which maintain large amount of user information. To utilize this information, identifying usage pattern of users is very important. Web usage mining is one of the processes of finding out this usage pattern and has many practical applications. Our paper discusses how association rules can be used to discover patterns in web usage mining. Our discussion starts with preprocessing of the given weblog, followed by clustering them and finding association rules. These rules provide knowledge that helps to improve website design, in advertising, web personalization etc.

  6. Thermography pattern analysis and separation

    Science.gov (United States)

    Gao, Bin; Bai, Libing; Woo, W. L.; Tian, Guiyun

    2014-06-01

    Analysis of thermography spatial-transient patterns has considerable potential to enable automatic identification and quantification of defects in non-destructive testing and evaluation. This Letter proposes a non-negative pattern separation model for eddy current pulsed thermography to automatically extract important spatial and time patterns according to the transient thermal sequences without any pre-training or prior knowledge. In particular, the method is scale-invariant, such that large differences in surface emissivity, hot spots, and cool areas with dynamic range of thermal contrast can be extracted. Finally, an artificial slot in a steel sample with shining, black strip on the surface is tested to validate the proposed method.

  7. Pattern Recognition Theory of Mind

    CERN Document Server

    de Paiva, Gilberto

    2009-01-01

    I propose that pattern recognition, memorization and processing are key concepts that can be a principle set for the theoretical modeling of the mind function. Most of the questions about the mind functioning can be answered by a descriptive modeling and definitions from these principles. An understandable consciousness definition can be drawn based on the assumption that a pattern recognition system can recognize its own patterns of activity. The principles, descriptive modeling and definitions can be a basis for theoretical and applied research on cognitive sciences, particularly at artificial intelligence studies.

  8. Mianningite, (□,Pb,Ce,Na) (U{sup 4+},Mn,U{sup 6+}) Fe{sup 3+}{sub 2}(Ti,Fe{sup 3+}){sub 18}O{sub 38}, a new member of the crichtonite group from Maoniuping REE deposit, Mianning county, southwest Sichuan, China

    Energy Technology Data Exchange (ETDEWEB)

    Ge, Xiangkun; Fan, Guang; Chen, Zhangru; Ai, Yujie [Beijing Research Institute of Uranium Geology, Beijing (China); Li, Guowu [China Univ. of Geosciences, Beijing (China). Lab. of Crystal Structure; Shen, Ganfu [Chengdu Institute of Geology and Mineral Resources, Chengdu (China)

    2017-05-15

    Mianningite (IMA 2014-072), ideally (□,Pb,Ce,Na)(U{sup 4+},Mn,U{sup 6+}) Fe{sup 3+}{sub 2}(Ti,Fe{sup 3+}){sub 18}O{sub 38}, is a new member of the crichtonite group from the Maoniuping REE deposit, Mianning county, Sichuan province, China. It was found in fractures of lamprophyre veins and in the contact between lamprophyre and a later quartz-alkali feldspar syenite dyke with REE mineralization, and is named after its type locality. Associated minerals are microcline, albite, quartz, iron-rich phlogopite, augite, muscovite, calcite, baryte, fluorite, epidote, pyrite, magnetite, hematite, galena, hydroxylapatite, titanite, ilmenite, rutile, garnet-group minerals, zircon, allanite-(Ce), monazite-(Ce), bastnaesite-(Ce), parisite-(Ce), maoniupingite-(Ce), thorite, pyrochlore-group minerals and chlorite. Mianningite occurs as opaque subhedral to euhedral tabular crystals, up to 1-2 mm in size, black in color and streak, and with a submetallic luster. Mianningite is brittle, with a conchoidal fracture. Its average micro-indentation hardness is 83.8 kg/mm{sup 2} (load 0.2 kg), which is equivalent to ∝6 on the Mohs hardness scale. Its measured and calculated densities are 4.62 (8) g/cm{sup 3} and 4.77 g/cm{sup 3}, respectively. Under reflected light, mianningite is grayish white, with no internal reflections. It appears isotropic and exhibits neither bireflectance nor pleochroism. The empirical formula, calculated on the basis of 38 O atoms per formula unit (apfu), is [□{sub 0.322}(Pb{sub 0.215}Ba{sub 0.037}Sr{sub 0.036}Ca{sub 0.010}){sub Σ0.298}(Ce{sub 0.128}La{sub 0.077}Nd{sub 0.012}){sub Σ0.217} (Na{sub 0.127}K{sub 0.036}){sub Σ0.163}]{sub Σ01.000}(U{sup 4+}{sub 0.447}Mn{sub 00.293}U{sup 6} {sup +}{sub 0.112}Y{sub 0.091}Zr{sub 0.023}Th{sub 0.011}){sub Σ0.977}(Fe{sup 3+}{sub 1.224}Fe{sup 2+}{sub 0.243}Mg{sub 0.023}P{sub 0.008}Si{sub 0.006} □{sub 0.496}){sub Σ2.000}(Ti{sub 12.464}Fe{sup 3+}{sub 5.292}V{sup 5+}{sub 0.118}Nb{sub 0.083}Al{sub 0.026}Cr{sup 3

  9. Pattern recognition and string matching

    CERN Document Server

    Cheng, Xiuzhen

    2002-01-01

    The research and development of pattern recognition have proven to be of importance in science, technology, and human activity. Many useful concepts and tools from different disciplines have been employed in pattern recognition. Among them is string matching, which receives much theoretical and practical attention. String matching is also an important topic in combinatorial optimization. This book is devoted to recent advances in pattern recognition and string matching. It consists of twenty eight chapters written by different authors, addressing a broad range of topics such as those from classifica­ tion, matching, mining, feature selection, and applications. Each chapter is self-contained, and presents either novel methodological approaches or applications of existing theories and techniques. The aim, intent, and motivation for publishing this book is to pro­ vide a reference tool for the increasing number of readers who depend upon pattern recognition or string matching in some way. This includes student...

  10. Ecoscapes: Geographical Patternings of Relations

    Directory of Open Access Journals (Sweden)

    Aimar Ventsel

    2012-06-01

    Full Text Available Book review of the publication Ecoscapes: Geographical Patternings of Relations. Edited by Gary Backhaus and John Murungi. Lanham, Boulder, New York, Toronto, Oxford, Lexington Books, 2006, xxxiii+241 pp.

  11. Learning Smooth Pattern Transformation Manifolds

    CERN Document Server

    Vural, Elif

    2011-01-01

    Manifold models provide low-dimensional representations that are useful for processing and analyzing data in a transformation-invariant way. In this paper, we study the problem of learning smooth pattern transformation manifolds from image sets that represent observations of geometrically transformed signals. In order to construct a manifold, we build a representative pattern whose transformations accurately fit various input images. We examine two objectives of the manifold building problem, namely, approximation and classification. For the approximation problem, we propose a greedy method that constructs a representative pattern by selecting analytic atoms from a continuous dictionary manifold. We present a DC (Difference-of-Convex) optimization scheme that is applicable to a wide range of transformation and dictionary models, and demonstrate its application to transformation manifolds generated by rotation, translation and anisotropic scaling of a reference pattern. Then, we generalize this approach to a s...

  12. Aging patterns in different environments

    DEFF Research Database (Denmark)

    Jouvet, Lionel; Steiner, Ulrich

    Environmental and genetic variability shape demographic patterns, but in most studies these factors are not controlled. We can therefore only make indirect inferences on the demographic effect of such environmental and genetic drivers. Here, we show for isogenic individual E. coli bacteria, under...... highly controlled environments of a microfluidic device, how diverse demographic patterns arise. We reveal patterns from classical mortality plateaus to non-senescence, simply by changing the temperature or the nutrient source. Such strong environmental influences revealed within a single strain...... of bacteria challenges our fundamental theories about the evolutionary shaping of aging patterns. Further, this mature technology now allows to test other mechanisms shaping aging such as antibiotic resistance, stress response pathways, or genotype....

  13. Casting Using A Polystyrene Pattern

    Science.gov (United States)

    Vasquez, Peter; Guenther, Bengamin; Vranas, Thomas; Veneris, Peter; Joyner, Michael

    1993-01-01

    New technique for making metal aircraft models saves significant amount of time and effort in comparison with conventional lost-wax method. Produces inexpensive, effective wind-tunnel models. Metal wind-tunnel model cast by use of polystyrene pattern.

  14. Pattern languages in HCI: A critical review

    OpenAIRE

    Dearden, A.; Finlay, J

    2006-01-01

    This article presents a critical review of patterns and pattern languages in human-computer interaction (HCI). In recent years, patterns and pattern languages have received considerable attention in HCI for their potential as a means for developing and communicating information and knowledge to support good design. This review examines the background to patterns and pattern languages in HCI, and seeks to locate pattern languages in relation to other approaches to interaction design. The revie...

  15. Pattern languages in HCI: a critical review

    OpenAIRE

    Dearden, Andy; Finlay, J

    2006-01-01

    This paper presents a critical review of patterns and pattern languages in human-computer interaction (HCI). In recent years, patterns and pattern languages have received considerable attention in HCI for their potential as a means for developing and communicating information and knowledge to support good design. This review examines the background to patterns and pattern languages in HCI, and seeks to locate pattern languages in relation to other approaches to interaction design. The review ...

  16. Pattern Recognition Using Associative Memories

    OpenAIRE

    Burles, Nathan John

    2014-01-01

    The human brain is extremely effective at performing pattern recognition, even in the presence of noisy or distorted inputs. Artificial neural networks attempt to imitate the structure of the brain, often with a view to mimicking its success. The binary correlation matrix memory (CMM) is a particular type of neural network that is capable of learning and recalling associations extremely quickly, as well as displaying a high storage capacity and having the ability to generalise from patterns a...

  17. Capacitance enhancement via electrode patterning

    Science.gov (United States)

    Ho, Tuan A.; Striolo, Alberto

    2013-11-01

    The necessity of increasing the energy density in electric double layer capacitors to meet current demand is fueling fundamental and applied research alike. We report here molecular dynamics simulation results for aqueous electrolytes near model electrodes. Particular focus is on the effect of electrode patterning on the structure of interfacial electrolytes, and on the potential drop between the solid electrodes and the bulk electrolytes. The latter is estimated by numerically integrating the Poisson equation using the charge densities due to water and ions accumulated near the interface as input. We considered uniform and patterned electrodes, both positively and negatively charged. The uniformly charged electrodes are modeled as graphite. The patterned ones are obtained by removing carbon atoms from the top-most graphene layer, yielding nanoscopic squares and stripes patterns. For simplicity, the patterned electrodes are effectively simulated as insulators (the charge remains localized on the top-most layer of carbon atoms). Our simulations show that the patterns alter the structure of water and the accumulation of ions at the liquid-solid interfaces. Using aqueous NaCl solutions, we found that while the capacitance calculated for three positively charged electrodes did not change much, that calculated for the negatively charged electrodes significantly increased upon patterning. We find that both water structure and orientation, as well as ion accumulation affect the capacitance. As electrode patterning affects differently water structure and ion accumulation, it might be possible to observe ion-specific effects. These results could be useful for advancing our understanding of electric double layer capacitors, capacitive desalination processes, as well as of fundamental interfacial electrolytes properties.

  18. Capacitance enhancement via electrode patterning

    Energy Technology Data Exchange (ETDEWEB)

    Ho, Tuan A.; Striolo, Alberto, E-mail: a.striolo@ucl.ac.uk [School of Chemical, Biological and Materials Engineering, The University of Oklahoma, Norman, Oklahoma 73019 (United States); Department of Chemical Engineering, University College London, Torrington Place, London WC1E 7JE (United Kingdom)

    2013-11-28

    The necessity of increasing the energy density in electric double layer capacitors to meet current demand is fueling fundamental and applied research alike. We report here molecular dynamics simulation results for aqueous electrolytes near model electrodes. Particular focus is on the effect of electrode patterning on the structure of interfacial electrolytes, and on the potential drop between the solid electrodes and the bulk electrolytes. The latter is estimated by numerically integrating the Poisson equation using the charge densities due to water and ions accumulated near the interface as input. We considered uniform and patterned electrodes, both positively and negatively charged. The uniformly charged electrodes are modeled as graphite. The patterned ones are obtained by removing carbon atoms from the top-most graphene layer, yielding nanoscopic squares and stripes patterns. For simplicity, the patterned electrodes are effectively simulated as insulators (the charge remains localized on the top-most layer of carbon atoms). Our simulations show that the patterns alter the structure of water and the accumulation of ions at the liquid-solid interfaces. Using aqueous NaCl solutions, we found that while the capacitance calculated for three positively charged electrodes did not change much, that calculated for the negatively charged electrodes significantly increased upon patterning. We find that both water structure and orientation, as well as ion accumulation affect the capacitance. As electrode patterning affects differently water structure and ion accumulation, it might be possible to observe ion-specific effects. These results could be useful for advancing our understanding of electric double layer capacitors, capacitive desalination processes, as well as of fundamental interfacial electrolytes properties.

  19. Visualizing Data Patterns with Micromaps

    CERN Document Server

    Carr, Daniel B

    2010-01-01

    After more than 15 years of development drawing on research in cognitive psychology, statistical graphics, computer science, and cartography, micromap designs are becoming part of mainstream statistical visualizations. Bringing together the research of two leaders in this field, "Visualizing Data Patterns with Micromaps" presents the many design variations and applications of micromaps, which link statistical information to an organized set of small maps. This full-color book helps readers simultaneously explore the statistical and geographic patterns in their data. After illustratin

  20. Streaming patterns in Faraday waves

    CERN Document Server

    Périnet, Nicolas; Urra, Héctor; Mujica, Nicolás; Gordillo, Leonardo

    2016-01-01

    Waves patterns in the Faraday instability have been studied for decades. Besides the rich dynamics that can be observed on the waves at the interface, Faraday waves hide beneath them an elusive range of flow patterns --or streaming patterns-- which have not been studied in detail until now. The streaming patterns are responsible for a net circulation in the flow which are reminiscent of convection cells. In this article, we analyse these streaming flows by conducting experiments in a Faraday-wave setup. To visualize the flows, tracers are used to generate both trajectory maps and to probe the streaming velocity field via Particle Image Velocimetry (PIV). We identify three types of patterns and experimentally show that identical Faraday waves can mask streaming patterns that are qualitatively very different. Next we propose a three-dimensional model that explains streaming flows in quasi-inviscid fluids. We show that the streaming inside the fluid arises from a complex coupling between the bulk and the boundar...

  1. Behavior of rare earth elements in coexisting manganese macronodules, micronodules, and sediments from the central Indian Basin

    Digital Repository Service at National Institute of Oceanography (India)

    Pattan, J.N.; Colley, S.; Higgs, N.C.

    Associated manganese macronodules, micronodules, and sediments from the Central Indian Basin (CIB) were analyzed for major, trace, and rare earth elements (REE) to understand REE carrier phases and their fractionation pattern among three...

  2. Gastric siderosis: patterns and significance.

    Science.gov (United States)

    Marginean, Esmeralda C; Bennick, Michael; Cyczk, Jan; Robert, Marie E; Jain, Dhanpat

    2006-04-01

    Recently, we encountered 2 cases of diffuse iron deposition in gastric antral and fundic glandular epithelium, which in 1 patient eventually led to the diagnosis of hemochromatosis. Gastric mucosal siderosis (GS) has previously been described in hemochromatosis patients, alcoholics, and in association with iron medications. However, the prevalence of various patterns of iron deposition in the gastric mucosa and their clinical significance have not been studied in detail. The 2 index cases mentioned above and 500 additional consecutive gastric biopsies examined over a period of 8 months at our institution were stained for iron by the Prussian blue method. In addition, all patients with genetic hemochromatosis diagnosed by liver biopsy in our department between 1998 and 2003 who also had gastric biopsies were identified from the surgical pathology files and included in the study (n = 3). The location of iron deposition [stromal cells (endothelium, fibroblasts, macrophages), glandular epithelium, or extracellular] was recorded and subjectively graded as 1+ to 3+ according to the severity of deposition within the mucosa. Relevant histologic changes (inflammation, presence of H. pylori, ulceration) and clinical features were reviewed. Three patterns of GS were identified: A) "nonspecific GS" with predominant iron deposition in the stromal cells including macrophages, and focally in epithelium; B) "iron-pill gastritis" with often mild gastritis and reactive gastropathy type changes, and mostly extracellular deposition with focal stromal cells and epithelial deposition; and C) predominant deposition in antral and fundic glandular epithelium. Of the 500 cases studied, a total of 18 (3.6%) cases were found to have GS. Of these 18 cases, 11 (2.2%) showed pattern A, 4 (0.8%) showed pattern B, and 3 (0.6%) showed pattern C. The GS in patterns A and B was always focal or patchy (1+ to 2+), whereas in pattern C it was generally diffuse and strong (2+ to 3+). A history of oral

  3. REE geochemistry application in discrimination of metallogenic system and ore genesis: An example from iron polymetallic orefield in Taliabu Island, Indonesia%稀土元素地球化学在成矿系统厘定及矿床成因分析中的应用——以印度尼西亚塔里亚布岛铁多金属矿田为例

    Institute of Scientific and Technical Information of China (English)

    韩世礼; 张术根; 丁俊; 徐忠发; 秦新龙

    2012-01-01

    以印度尼西亚塔里亚布岛铁多金属矿田为典型实例,探讨了稀土元素地球化学在厘定成矿系统中的作用及相同成矿系统的稀土元素地球化学叠加与演化规律.研究表明:除辉绿岩外,花岗岩、大理岩、变质砂岩及矽卡岩都是铁多金属成矿系统的组成部分,矿浆型和矽卡岩型磁铁矿矿石及铜锌硫化物矿石均属相同系统的成矿作用产物.矿浆型磁铁矿矿石为该系统的一个相对独立的子系统,即印支期花岗岩结晶分异成矿系统;矽卡岩型磁铁矿矿石和热液充填交代型铜锌硫化物矿石同属一个子系统,即接触交代成矿系统;两个子系统是一个从岩浆阶段至热液阶段的完整成矿演化系列.从矿浆型矿石至接触交代型再到热液充填交代型负铕异常逐渐减弱,分馏程度逐渐增强,由重稀土富集型转变为轻稀土富集型.因此,稀土元素地球化学研究是厘定复杂成矿系统、分析矿床成因的有效手段.%Taking the iron polymetallic orefield in Taliabu Island, Indonesia as an example, the application of REE geochemistry in discrimination of metallogenic system and the regularities of REE superposition and evolution in the same mineralization system were investigated. The results show that in Taliabu Island, granite, marble, metamorphic sandstone and skarn are the composition parts of the iron polymetallic metallogenic system except for diabase. Ore magma and skarn magnetite ores as well as Cu-Zn sulfide ores are originated from the same metallogenic system. In this system, ore magma type is a relatively independent subsystem, that is, a crystal fractionation system of Indosinian granites; skarn type and hydrothermal filling type belong to another subsystem, that is, a contact metasomatic metallogenic system. Two subsystems belong to a complete mineralization system from magma stage to hydrothermal stage. From ore magma type to skarn type to hydrothermal filling type

  4. Monolayer patterning using ketone dipoles.

    Science.gov (United States)

    Kim, Min Kyoung; Xue, Yi; Pašková, Tereza; Zimmt, Matthew B

    2013-08-14

    The self-assembly of multi-component monolayers with designed patterns requires molecular recognition among components. Dipolar interactions have been found to influence morphologies of self-assembled monolayers and can affect molecular recognition functions. Ketone groups have large dipole moments (2.6 D) and are easily incorporated into molecules. The potential of ketone groups for dipolar patterning has been evaluated through synthesis of two 1,5-disubstituted anthracenes bearing mono-ketone side chains, STM characterization of monolayers self-assembled from their single and two component solutions and molecular mechanics simulations to determine their self-assembly energetics. The results reveal that (i) anthracenes bearing self-repulsive mono-ketone side chains assemble in an atypical monolayer morphology that establishes dipolar attraction, instead of repulsion, between ketones in adjacent side chains; (ii) pairs of anthracene molecules whose self-repulsive ketone side chains are dipolar complementary spontaneously assemble compositionally patterned monolayers, in which the two components segregate into neighboring, single component columns, driven by side chain dipolar interactions; (iii) compositionally patterned monolayers also assemble from dipolar complementary anthracene pairs that employ different dipolar groups (ketones or CF2 groups) in their side chains; (iv) the ketone group, with its larger dipole moment and size, provides comparable driving force for patterned monolayer formation to that of the smaller dipole, and smaller size, CF2 group.

  5. Interesting Multi-Relational Patterns

    CERN Document Server

    Spyropoulou, Eirini

    2011-01-01

    Mining patterns from multi-relational data is a problem attracting increasing interest within the data mining community. Traditional data mining approaches are typically developed for highly simplified types of data, such as an attribute-value table or a binary database, such that those methods are not directly applicable to multi-relational data. Nevertheless, multi-relational data is a more truthful and therefore often also a more powerful representation of reality. Mining patterns of a suitably expressive syntax directly from this representation, is thus a research problem of great importance. In this paper we introduce a novel approach to mining patterns in multi-relational data. We propose a new syntax for multi-relational patterns as complete connected subgraphs in a representation of the database as a K-partite graph. We show how this pattern syntax is generally applicable to multirelational data, while it reduces to well-known tiles [7] when the data is a simple binary or attribute-value table. We pro...

  6. EUV patterning successes and frontiers

    Science.gov (United States)

    Felix, Nelson; Corliss, Dan; Petrillo, Karen; Saulnier, Nicole; Xu, Yongan; Meli, Luciana; Tang, Hao; De Silva, Anuja; Hamieh, Bassem; Burkhardt, Martin; Mignot, Yann; Johnson, Richard; Robinson, Chris; Breton, Mary; Seshadri, Indira; Dunn, Derren; Sieg, Stuart; Miller, Eric; Beique, Genevieve; Labonte, Andre; Sun, Lei; Han, Geng; Verduijn, Erik; Han, Eunshoo; Kim, Bong Cheol; Kim, Jongsu; Hontake, Koichi; Huli, Lior; Lemley, Corey; Hetzer, Dave; Kawakami, Shinichiro; Matsunaga, Koichi

    2016-03-01

    The feature scaling and patterning control required for the 7nm node has introduced EUV as a candidate lithography technology for enablement. To be established as a front-up lithography solution for those requirements, all the associated aspects with yielding a technology are also in the process of being demonstrated, such as defectivity process window through patterning transfer and electrical yield. This paper will review the current status of those metrics for 7nm at IBM, but also focus on the challenges therein as the industry begins to look beyond 7nm. To address these challenges, some of the fundamental process aspects of holistic EUV patterning are explored and characterized. This includes detailing the contrast entitlement enabled by EUV, and subsequently characterizing state-of-the-art resist printing limits to realize that entitlement. Because of the small features being considered, the limits of film thinness need to be characterized, both for the resist and underlying SiARC or inorganic hardmask, and the subsequent defectivity, both of the native films and after pattern transfer. Also, as we prepare for the next node, multipatterning techniques will be validated in light of the above, in a way that employs the enabling aspects of EUV as well. This will thus demonstrate EUV not just as a technology that can print small features, but one where all aspects of the patterning are understood and enabling of a manufacturing-worthy technology.

  7. Techniques for Specifying Bug Patterns

    Energy Technology Data Exchange (ETDEWEB)

    Quinlan, D J; Vuduc, R W; Misherghi, G

    2007-04-30

    We present our on-going work to develop techniques for specifying source code signatures of bug patterns. Specifically, we discuss two approaches. The first approach directly analyzes a program in the intermediate representation (IR) of the ROSE compiler infrastructure using ROSE's API. The second analyzes the program using the bddbddb system of Lam, Whaley, et al.. In this approach, we store the IR produced by ROSE as a relational database, express patterns as declarative inference rules on relations in the language Datalog, and bddbddb implements the Datalog programs using binary decision diagram (BDD) techniques. Both approaches readily apply to large-scale applications, since ROSE provides full type analysis, control flow, and other available analysis information. In this paper, we primarily consider bug patterns expressed with respect to the structure of the source code or the control flow, or both. More complex techniques to specify patterns that are functions of data flow properties may be addressed by either of the above approaches, but are not directly treated here. Our Datalog-based work includes explicit support for expressing patterns on the use of the Message Passing Interface (MPI) in parallel distributed memory programs. We show examples of this on-going work as well.

  8. Vertebrate Embryonic Cleavage Pattern Determination.

    Science.gov (United States)

    Hasley, Andrew; Chavez, Shawn; Danilchik, Michael; Wühr, Martin; Pelegri, Francisco

    2017-01-01

    The pattern of the earliest cell divisions in a vertebrate embryo lays the groundwork for later developmental events such as gastrulation, organogenesis, and overall body plan establishment. Understanding these early cleavage patterns and the mechanisms that create them is thus crucial for the study of vertebrate development. This chapter describes the early cleavage stages for species representing ray-finned fish, amphibians, birds, reptiles, mammals, and proto-vertebrate ascidians and summarizes current understanding of the mechanisms that govern these patterns. The nearly universal influence of cell shape on orientation and positioning of spindles and cleavage furrows and the mechanisms that mediate this influence are discussed. We discuss in particular models of aster and spindle centering and orientation in large embryonic blastomeres that rely on asymmetric internal pulling forces generated by the cleavage furrow for the previous cell cycle. Also explored are mechanisms that integrate cell division given the limited supply of cellular building blocks in the egg and several-fold changes of cell size during early development, as well as cytoskeletal specializations specific to early blastomeres including processes leading to blastomere cohesion. Finally, we discuss evolutionary conclusions beginning to emerge from the contemporary analysis of the phylogenetic distributions of cleavage patterns. In sum, this chapter seeks to summarize our current understanding of vertebrate early embryonic cleavage patterns and their control and evolution.

  9. Tungsten Mineralization and Mica REE Geochemistry,Huangsha,Jiangxi

    Institute of Scientific and Technical Information of China (English)

    梁书艺; 夏宏远

    1991-01-01

    The Huangsha Ag-rich tungsten deposit is genetically related to a buried granite which shows apparent vertical zoning in alteration.Greisen-type W(Mo) ores coccur at the top or the intrusive and sulfide-wolframite-quartz veins developed at the major stage of mineralization are present in low-grade metamorphic rocks in the outer-contacts.The veins exhibit a reversed zonation in the vertical section with silver concentrated in the lower part in association with sulfides.Micas,characterized by high Si and low Al.are extensively developed both in the granite and in the veins.They have similar cell parameters.belonging to 2M1 type,but those in the veins are understanding of the petrogenesis, evolution and mineralization of the granite.

  10. Implications of Competition for Rare Earth Elements (REE) in Africa

    Science.gov (United States)

    2011-03-15

    48,000 China 120,000 120,000 36,000,000 Commonwealth of Independent States NA NA...of the U.S. Geological Survey’s 2008 Mineral Yearbook provides an excellent graphic representation of where the United States obtains its major...economy. To date, the European Union (EU) and the U.S. have not granted them any such request. Professor Pang Zhongying from Nankai University

  11. Patterns of Apoplectic Dysarthria and Acupuncture Treatment

    Institute of Scientific and Technical Information of China (English)

    ZHANG Jian-bin; HUANG Guo-qi

    2003-01-01

    In accordance with the feature of apoplectic dysarthria, it is divided into three types of labial pattern, lingual pattern and laryngeal pattern.The therapeutic methods are respectively explained with case examples.

  12. Separation vortices and pattern formation

    DEFF Research Database (Denmark)

    Andersen, Anders Peter; Bohr, Tomas; Schnipper, Teis

    2010-01-01

    In this paper examples are given of the importance of flow separation for fluid patterns at moderate Reynolds numbers—both in the stationary and in the time-dependent domain. In the case of circular hydraulic jumps, it has been shown recently that it is possible to generalise the Prandtl–Kármán–P...... results for the vortex patterns behind a flapping foil in a flowing soap film, which shows the interaction and competition between the vortices shed from the round leading edge (like the von Kármán vortex street) and those created at the sharp trailing edge.......-time evolution of the sand ripple pattern, which has the surprising features that it breaks the local sand conservation and has long-range interaction, features that can be underpinned by experiments. Very similar vortex dynamics takes place around oscillating structures such as wings and fins. Here, we present...

  13. Efficient Frequent Pattern Tree Construction

    Directory of Open Access Journals (Sweden)

    D.Bujji Babu

    2014-03-01

    Full Text Available Association rule learning is a popular and well researched technique for discovering interesting relations between variables in large databases in the area of data mining. The association rules are a part of intelligent systems. Association rules are usually required to satisfy a user-specified minimum support and a user-specified minimum confidence at the same time. Apriori and FP-Growth algorithms are very familiar algorithms for association rule mining. In this paper we are more concentrated on the Construction of efficient frequent pattern trees. Here, we present the novel frequent pattern trees and the performance issues. The proposed trees are fast and efficient trees helps to extract the frequent patterns. This paper provides the major advantages in the FP-Growth algorithm for association rule mining with using the newly proposed approach.

  14. Classic ballet dancers postural patterns

    Directory of Open Access Journals (Sweden)

    Joseani Paulini Neves Simas

    2008-06-01

    Full Text Available The aim of this study was to evaluate classic ballet practice and its influence on postural patterns and (a identify the most frequent postural changes; (b determine the postural pattern; (c verify the existence of association of practice time and postural changes. The investigation was carried out in two stages: one, description in which 106 dancers participated; the other, causal comparative in which 50 dancers participated; and (a questionnaire; (b a checkerboard; (c postural chart; (d measure tape; (e camera and (f pedoscope were used as instrument. Descriptive and inferential statistics was used for analysis. The results revealed the most frequent postural changes such as hyperlordosis, unleveled shoulders and pronated ankles. Ballet seems to have negative implications in the postural development , affecting especially the vertebral spine, trunk and feet. The practice time was not a parameter to indicate the increase in postural changes. In conclusion, ballet may be associated with postural changes and determining a characteristic postural pattern.

  15. Patterning mechanisms controlling digit development

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Vertebrate digits are essential structures for movement,feeding and communication.Specialized regions of the developing limb bud including the zone of polarizing activity(ZPA),the apical ectodermal ridge(AER),and the non-ridge ectoderm regulate the patterning of digits.Although a series of signaling molecules have been characterized as patterning signals from the organizing centers,the delicate cellular and molecular mechanisms that interpret how these patterning signals control the detailed digit anatomy remain unclear.Recent studies from model organisms and human hand malformations provide new insights into the mechanisms regulating this process.Here,we review the current understanding of the genetic networks governing digit morphogenesis.

  16. Pattern Recognition by Combined Invariants

    Institute of Scientific and Technical Information of China (English)

    WANG Xiaohong; ZHAO Rongchun

    2001-01-01

    A feature-based recognition of objectsor patterns independent of their position, size, orien-tation and other variations has been the goal of muchrecent research. The existing approaches to invarianttwo-dimensional pattern recognition are useless whenpattern is blurred. In this paper, we present a novelpattern recognition system which can solve the prob-lem by using combined invariants as image features.The classification technique we choose for our systemis weighted normalized cross correlation. The mean ofthe intraclass standard deviations of the kth featureover the total number of prototypes for each class isused as a weighting factor during the classification pro-cess to improve recognition accuracy. The feasibilityof our pattern recognition system and the invarianceof the combined features with respect to translation,scaling, rotation and blurring are approved by numer-ical experiments on head images.

  17. Workflow patterns the definitive guide

    CERN Document Server

    Russell, Nick; ter Hofstede, Arthur H M

    2016-01-01

    The study of business processes has emerged as a highly effective approach to coordinating an organization's complex service- and knowledge-based activities. The growing field of business process management (BPM) focuses on methods and tools for designing, enacting, and analyzing business processes. This volume offers a definitive guide to the use of patterns, which synthesize the wide range of approaches to modeling business processes. It provides a unique and comprehensive introduction to the well-known workflow patterns collection -- recurrent, generic constructs describing common business process modeling and execution scenarios, presented in the form of problem-solution dialectics. The underlying principles of the patterns approach ensure that they are independent of any specific enabling technology, representational formalism, or modeling approach, and thus broadly applicable across the business process modeling and business process technology domains. The authors, drawing on extensive research done by...

  18. Turing patterns and biological explanation

    DEFF Research Database (Denmark)

    Serban, Maria

    2017-01-01

    Turing patterns are a class of minimal mathematical models that have been used to discover and conceptualize certain abstract features of early biological development. This paper examines a range of these minimal models in order to articulate and elaborate a philosophical analysis of their episte......Turing patterns are a class of minimal mathematical models that have been used to discover and conceptualize certain abstract features of early biological development. This paper examines a range of these minimal models in order to articulate and elaborate a philosophical analysis......, promoting theory exploration, and acting as constitutive parts of empirically adequate explanations of naturally occurring phenomena, such as biological pattern formation. Focusing on the roles that minimal model explanations play in science motivates the adoption of a broader diachronic view of scientific...

  19. Participation patterns in adult education

    DEFF Research Database (Denmark)

    Desjardins, Richard; Rubenson, Kjell

    2013-01-01

    of investment in the development and maintenance of skills over the lifespan of individuals is to a large extent interconnected with a high-level of non-market coordination via institutional arrangements and/or specific public policy measures. Such arrangements and measures are seen to alleviate coordination......This article focuses on evidence regarding cross-national patterns of participation in adult education and an interpretation of these patterns from an institutional and public policy perspective. The interpretation follows from the perspective that sustaining high and widely distributed levels...... problems that otherwise lead to underinvestment in skills and/or inequity in the distribution of access to education and training and hence skills. Hence, it is argued that institutional contexts and public policy measures condition participation patterns in adult education, and are thus worthwhile...

  20. Patterns of Software Development Process

    Directory of Open Access Journals (Sweden)

    Sandro Javier Bolaños Castro

    2011-12-01

    Full Text Available "Times New Roman","serif";mso-fareast-font-family:"Times New Roman";mso-ansi-language:EN-US;mso-fareast-language:EN-US;mso-bidi-language:AR-SA">This article presents a set of patterns that can be found to perform best practices in software processes that are directly related to the problem of implementing the activities of the process, the roles involved, the knowledge generated and the inputs and outputs belonging to the process. In this work, a definition of the architecture is encouraged by using different recurrent configurations that strengthen the process and yield efficient results for the development of a software project. The patterns presented constitute a catalog, which serves as a vocabulary for communication among project participants [1], [2], and also can be implemented through software tools, thus facilitating patterns implementation [3]. Additionally, a tool that can be obtained under GPL (General Public license is provided for this purpose

  1. Pattern Formation on Networks: from Localised Activity to Turing Patterns

    Science.gov (United States)

    McCullen, Nick; Wagenknecht, Thomas

    2016-06-01

    Networks of interactions between competing species are used to model many complex systems, such as in genetics, evolutionary biology or sociology and knowledge of the patterns of activity they can exhibit is important for understanding their behaviour. The emergence of patterns on complex networks with reaction-diffusion dynamics is studied here, where node dynamics interact via diffusion via the network edges. Through the application of a generalisation of dynamical systems analysis this work reveals a fundamental connection between small-scale modes of activity on networks and localised pattern formation seen throughout science, such as solitons, breathers and localised buckling. The connection between solutions with a single and small numbers of activated nodes and the fully developed system-scale patterns are investigated computationally using numerical continuation methods. These techniques are also used to help reveal a much larger portion of of the full number of solutions that exist in the system at different parameter values. The importance of network structure is also highlighted, with a key role being played by nodes with a certain so-called optimal degree, on which the interaction between the reaction kinetics and the network structure organise the behaviour of the system.

  2. Parametric Transverse Patterns in Broad Aperture Lasers

    DEFF Research Database (Denmark)

    Grigorieva, E.V.; Kashchenko, S.A.; Mosekilde, Erik

    1998-01-01

    Parametrically generated optical patterns are investigated for finite and large-scale transverse aperture lasers. Standing and rotating patterns as well as periodic and chaotic pattern alternations are described in the framework of the amplitude equation formalism. Sensitive dependence on the geo......Parametrically generated optical patterns are investigated for finite and large-scale transverse aperture lasers. Standing and rotating patterns as well as periodic and chaotic pattern alternations are described in the framework of the amplitude equation formalism. Sensitive dependence...

  3. Wilf classification of doubly generalized permutation patterns

    CERN Document Server

    Parviainen, Robert

    2009-01-01

    We classify all doubly generalized patterns of length two and three according to the number of permutations avoiding them. These patterns were recently defined by Bousquet-Melou et. al., and are natural generalizations of Babson and Steingrimsson's generalized patterns. The patterns are divided into seven and 24 Wilf classes, for lengths two and three, respectively. For most of the patterns an explicit form for the number of permutations avoiding the pattern is given.

  4. Spatiotemporal Wave Patterns: Information Dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Mikhail Rabinovich; Lev Tsimring

    2006-01-20

    Pattern formation has traditionally been studied in non-equilibrium physics from the viewpoint of describing the basic structures and their interactions. While this is still an important area of research, the emphasis in the last few years has shifted towards analysis of specific properties of patterns in various complex media. For example, diverse and unexpected phenomena occur in neuro-like media that are characterized by highly non-trivial local dynamics. We carried out an active research program on analysis of spatio-temporal patterns in various physical systems (convection, oscillating fluid layer, soap film), as well as in neuro-like media, with an emphasis on informational aspects of the dynamics. Nonlinear nonequilibrium media and their discrete analogs have a unique ability to represent, memorize, and process the information contained in spatio-temporal patterns. Recent neurophysiological experiments demonstrated a certain universality of spatio-temporal representation of information by neural ensembles. Information processing is also revealed in the spatio-temporal dynamics of cellular patterns in nonequilibrium media. It is extremely important for many applications to study the informational aspects of these dynamics, including the origins and mechanisms of information generation, propagation and storage. Some of our results are: the discovery of self-organization of periodically oscillatory patterns in chaotic heterogeneous media; the analysis of the propagation of the information along a chaotic media as function of the entropy of the signal; the analysis of wave propagation in discrete non-equilibrium media with autocatalytic properties, which simulates the calcium dynamics in cellular membranes. Based on biological experiments we suggest the mechanism by which the spatial sensory information is transferred into the spatio-temporal code in the neural media. We also found a new mechanism of self-pinning in cellular structures and the related phenomenon

  5. Type-safe pattern combinators

    DEFF Research Database (Denmark)

    Rhiger, Morten

    2009-01-01

    Macros still haven't made their way into typed higher-order programming languages such as Haskell and Standard ML. Therefore, to extend the expressiveness of Haskell or Standard ML, one must express new linguistic features in terms of functions that fit within the static type systems of these lan...... of these languages. This is particularly challenging when introducing features that span across multiple types and that bind variables. We address this challenge by developing, in a step by step manner, mechanisms for encoding patterns and pattern matching in Haskell in a type-safe way....

  6. Glass strengthening and patterning methods

    Science.gov (United States)

    Harper, David C; Wereszczak, Andrew A; Duty, Chad E

    2015-01-27

    High intensity plasma-arc heat sources, such as a plasma-arc lamp, are used to irradiate glass, glass ceramics and/or ceramic materials to strengthen the glass. The same high intensity plasma-arc heat source may also be used to form a permanent pattern on the glass surface--the pattern being raised above the glass surface and integral with the glass (formed of the same material) by use of, for example, a screen-printed ink composition having been irradiated by the heat source.

  7. Patterns in Permutations and Words

    CERN Document Server

    Kitaev, Sergey

    2011-01-01

    There has been considerable interest recently in the subject of patterns in permutations and words, a new branch of combinatorics with its roots in the works of Rotem, Rogers, and Knuth in the 1970s. Consideration of the patterns in question has been extremely interesting from the combinatorial point of view, and it has proved to be a useful language in a variety of seemingly unrelated problems, including the theory of Kazhdan--Lusztig polynomials, singularities of Schubert varieties, interval orders, Chebyshev polynomials, models in statistical mechanics, and various sorting algorithms, inclu

  8. Separation vortices and pattern formation

    DEFF Research Database (Denmark)

    Andersen, Anders Peter; Bohr, Tomas; Schnipper, Teis

    2010-01-01

    In this paper examples are given of the importance of flow separation for fluid patterns at moderate Reynolds numbers—both in the stationary and in the time-dependent domain. In the case of circular hydraulic jumps, it has been shown recently that it is possible to generalise the Prandtl–Kármán–P...... results for the vortex patterns behind a flapping foil in a flowing soap film, which shows the interaction and competition between the vortices shed from the round leading edge (like the von Kármán vortex street) and those created at the sharp trailing edge....

  9. Noise and dynamical pattern selection

    CERN Document Server

    Kurtze, D A

    1995-01-01

    In pattern forming systems such as Rayleigh-Benard convection or directional solidification, a large number of linearly stable, patterned steady states exist when the basic, simple steady state is unstable. Which of these steady states will be realized in a given experiment appears to depend on unobservable details of the system's initial conditions. We show, however, that weak, Gaussian white noise drives such a system toward a preferred wave number which depends only on the system parameters and is independent of initial conditions. We give a prescription for calculating this wave number, analytically near the onset of instability and numerically otherwise.

  10. Micro-pattern gaseous detectors

    CERN Document Server

    Shekhtman, L I

    2002-01-01

    Introduced at the end of 1980s micro-pattern gas detectors perform much better than classic wire chambers. They allow to achieve both excellent localization accuracy and high rate capability that make this technology attractive for charged particle tracking at high luminosity colliders. During its evolution micro-pattern gas technology gave raise to many different types of devices such as micro-strip gas chambers, MicroMEGAS, CAT and gas electron multipliers. Essential improvements in the performance of the detectors were achieved especially in what concerned long-term performance: aging and resistance to accidental discharges.

  11. Pattern formations and oscillatory phenomena

    CERN Document Server

    Kinoshita, Shuichi

    2013-01-01

    Patterns and their formations appear throughout nature, and are studied to analyze different problems in science and make predictions across a wide range of disciplines including biology, physics, mathematics, chemistry, material science, and nanoscience. With the emergence of nanoscience and the ability for researchers and scientists to study living systems at the biological level, pattern formation research has become even more essential. This book is an accessible first of its kind guide for scientists, researchers, engineers, and students who require a general introduction to thi

  12. Memristor-based pattern matching

    Science.gov (United States)

    Klimo, Martin; Such, Ondrej; Skvarek, Ondrej; Fratrik, Milan

    2014-10-01

    Pattern matching is a machine learning area that requires high-performance hardware. It has been hypothesized that massively parallel designs, which avoid von Neumann architecture, could provide a significant performance boost. Such designs can advantageously use memristive switches. This paper discusses a two-stage design that implements the induced ordered weighted average (IOWA) method for pattern matching. We outline the circuit structure and discuss how a functioning circuit can be achieved using metal oxide devices. We describe our simulations of memristive circuits and illustrate their performance on a vowel classification task.

  13. Continental shelves as potential resource of rare earth elements.

    Science.gov (United States)

    Pourret, Olivier; Tuduri, Johann

    2017-07-19

    The results of this study allow the reassessment of the rare earth elements (REE) external cycle. Indeed, the river input to the oceans has relatively flat REE patterns without cerium (Ce) anomalies, whereas oceanic REE patterns exhibit strong negative Ce anomalies and heavy REE enrichment. Indeed, the processes at the origin of seawater REE patterns are commonly thought to occur within the ocean masses themselves. However, the results from the present study illustrate that seawater-like REE patterns already occur in the truly dissolved pool of river input. This leads us to favor a partial or complete removal of the colloidal REE pool during estuarine mixing by coagulation, as previously shown for dissolved humic acids and iron. In this latter case, REE fractionation occurs because colloidal and truly dissolved pools have different REE patterns. Thus, the REE patterns of seawater could be the combination of both intra-oceanic and riverine processes. In this study, we show that the Atlantic continental shelves could be considered potential REE traps, suggesting further that shelf sediments could potentially become a resource for REE, similar to metalliferous deep sea sediments.

  14. Afrikaans Syllabification Patterns

    Directory of Open Access Journals (Sweden)

    Tilla Fick

    2010-01-01

    Full Text Available In contrast to English, automatic hyphenation by computer of Afrikaans words is a problem that still needs to be addressed, since errors are still often encountered in printed text. An initial step in this task is the ability to automatically syllabify words. Since new words are created continuously by joining words, it is necessary to develop an “intelligent” technique for syllabification. As a first phase of the research, we consider only the orthographic information of words, and disregard both syntactic and morphological information. This approach allows us to use machine-learning techniques such as artificial neural networks and decision trees that are known for their pattern recognition abilities. Both these techniques are trained with isolated patterns consisting of input patterns and corresponding outputs (or targets that indicate whether the input pattern should be split at a certain position, or not. In the process of compiling a list of syllabified words from which to generate training data for the  syllabification problem, irregular patterns were identified. The same letter patterns are split differently in different words and complete words that are spelled identically are split differently due to meaning. We also identified irregularities in and between  the different dictionaries that we used. We examined the influence range of letters that are involved in irregularities. For example, for their in agter-ente and vaste-rente we have to consider three letters to the left of r to be certain where the hyphen should be inserted. The influence range of the k in verstek-waarde and kleinste-kwadrate is four to the left and three to the right. In an analysis of letter patterns in Afrikaans words we found that the letter e has the highest frequency overall (16,2% of all letters in the word list. The frequency of words starting with s is the highest, while the frequency of words ending with e is the highest. It is important to

  15. Primary description of surface water phytoplankton pigment patterns in the Bay of Bengal

    Digital Repository Service at National Institute of Oceanography (India)

    Naik, R.K.; Anil, A.C.; Narale, D.D.; Chitari, R.R.; Kulkarni, V.V.

    . Biogeochemical controls and feedbacks on ocean primary production. Science 281, 200-206. Gibb, S.W., Barlow, R.G., Cummings, D.G., Rees, N.W., Trees, C.C., Holligan, P., Suggett, D., 2000. Surface phytoplankton pigment distributions in the Atlantic Ocean...

  16. Pattern Matching in Multiple Streams

    CERN Document Server

    Clifford, Raphael; Porat, Ely; Sach, Benjamin

    2012-01-01

    We investigate the problem of deterministic pattern matching in multiple streams. In this model, one symbol arrives at a time and is associated with one of s streaming texts. The task at each time step is to report if there is a new match between a fixed pattern of length m and a newly updated stream. As is usual in the streaming context, the goal is to use as little space as possible while still reporting matches quickly. We give almost matching upper and lower space bounds for three distinct pattern matching problems. For exact matching we show that the problem can be solved in constant time per arriving symbol and O(m+s) words of space. For the k-mismatch and k-differences problems we give O(k) time solutions that require O(m+ks) words of space. In all three cases we also give space lower bounds which show our methods are optimal up to a single logarithmic factor. Finally we set out a number of open problems related to this new model for pattern matching.

  17. Patterns of Propaganda and Persuasion.

    Science.gov (United States)

    Rank, Hugh

    Because children are exposed to highly professional sales pitches on television and because the old material produced by the Institute of Propaganda Analysis is outdated and in error, a new tool for the analysis of propaganda and persuasion is called for. Such a tool is the intensify/downplay pattern analysis chart, which includes the basic…

  18. A Lesson in Number Pattern

    Science.gov (United States)

    Fletcher, Rodney

    2008-01-01

    This article presents a guided investigation into the spacial relationships between the centres of the squares in a Fibonacci tiling. It is essentially a lesson in number pattern, but includes work with surds, coordinate geometry, and some elementary use of complex numbers. The investigation could be presented to students in a number of ways…

  19. SNP interaction pattern identifier (SIPI)

    DEFF Research Database (Denmark)

    Lin, Hui-Yi; Chen, Dung-Tsa; Huang, Po-Yu

    2016-01-01

    MOTIVATION: Testing SNP-SNP interactions is considered as a key for overcoming bottlenecks of genetic association studies. However, related statistical methods for testing SNP-SNP interactions are underdeveloped. RESULTS: We propose the SNP Interaction Pattern Identifier (SIPI), which tests 45...

  20. Female pattern alopecia: current perspectives

    Directory of Open Access Journals (Sweden)

    Levy LL

    2013-08-01

    Full Text Available Lauren L Levy, Jason J Emer Department of Dermatology, Mount Sinai School of Medicine, New York, NY, USA Abstract: Hair loss is a commonly encountered problem in clinical practice, with men presenting with a distinctive pattern involving hairline recession and vertex balding (Norwood-Hamilton classification and women exhibiting diffuse hair thinning over the crown (increased part width and sparing of the frontal hairline (Ludwig classification. Female pattern hair loss has a strikingly overwhelming psychological effect; thus, successful treatments are necessary. Difficulty lies in successful treatment interventions, as only two medications – minoxidil and finasteride – are approved for the treatment of androgenetic alopecia, and these medications offer mediocre results, lack of a permanent cure, and potential complications. Hair transplantation is the only current successful permanent option, and it requires surgical procedures. Several other medical options, such as antiandrogens (eg, spironolactone, oral contraceptives, cyproterone, flutamide, dutasteride, prostaglandin analogs (eg, bimatoprost, latanoprost, and ketoconazole are reported to be beneficial. Laser and light therapies have also become popular despite the lack of a profound benefit. Management of expectations is crucial, and the aim of therapy, given the current therapeutic options, is to slow or stop disease progression with contentment despite patient expectations of permanent hair regrowth. This article reviews current perspectives on therapeutic options for female pattern hair loss. Keywords: androgenetic alopecia, female pattern hair loss, minoxidil, finasteride, antiandrogens, spironolactone