Science.gov

Sample records for 100-nr-2 apatite treatability

  1. 100-NR-2 Apatite Treatability Test: Fall 2010 Tracer Infiltration Test (White Paper)

    SciTech Connect

    Vermeul, Vincent R.; Fritz, Brad G.; Fruchter, Jonathan S.; Greenwood, William J.; Johnson, Timothy C.; Horner, Jacob A.; Strickland, Christopher E.; Szecsody, James E.; Williams, Mark D.

    2011-04-14

    change and the associated change in moisture content so that 4D images of moisture content change can be generated. Results from this field test will be available for any future Ca-citrate-PO4 amendment infiltration tests, which would be designed to evaluate the efficacy of using near surface application of amendments to form apatite mineral phases in the upper portion of the zone of water table fluctuation.

  2. 100-NR-2 Apatite Treatability Test: High-Concentration Calcium-Citrate-Phosphate Solution Injection for In Situ Strontium-90 Immobilization

    SciTech Connect

    Vermeul, Vincent R.; Fritz, Brad G.; Fruchter, Jonathan S.; Szecsody, James E.; Williams, Mark D.

    2010-09-01

    Following an evaluation of potential strontium-90 (90Sr) treatment technologies and their applicability under 100-NR-2 hydrogeologic conditions, the U.S. Department of Energy (DOE), Fluor Hanford, Inc. (now CH2M Hill Plateau Remediation Company [CHPRC]), Pacific Northwest National Laboratory, and the Washington State Department of Ecology agreed that the long-term strategy for groundwater remediation at the 100-N Area should include apatite as the primary treatment technology. This agreement was based on results from an evaluation of remedial alternatives that identified the apatite permeable reactive barrier (PRB) technology as the approach showing the greatest promise for reducing 90Sr flux to the Columbia River at a reasonable cost. This letter report documents work completed to date on development of a high-concentration amendment formulation and initial field-scale testing of this amendment solution.

  3. Interim Report: 100-NR-2 Apatite Treatability Test: Low Concentration Calcium Citrate-Phosphate Solution Injection for In Situ Strontium-90 Immobilization

    SciTech Connect

    Williams, Mark D.; Fritz, Brad G.; Mendoza, Donaldo P.; Rockhold, Mark L.; Thorne, Paul D.; Xie, YuLong; Bjornstad, Bruce N.; Mackley, Rob D.; Newcomer, Darrell R.; Szecsody, James E.; Vermeul, Vincent R.

    2008-07-11

    Following an evaluation of potential Sr-90 treatment technologies and their applicability under 100-NR-2 hydrogeologic conditions, U.S. Department of Energy, Fluor Hanford, Inc., Pacific Northwest National Laboratory, and the Washington Department of Ecology agreed that the long-term strategy for groundwater remediation at 100-N Area will include apatite sequestration as the primary treatment, followed by a secondary treatment if necessary (most likely phytoremediation). Since then, the agencies have worked together to agree on which apatite sequestration technology has the greatest chance of reducing Sr-90 flux to the river at a reasonable cost. In July 2005, aqueous injection, (i.e., the introduction of apatite-forming chemicals into the subsurface) was endorsed as the interim remedy and selected for field testing. Studies are in progress to assess the efficacy of in situ apatite formation by aqueous solution injection to address both the vadose zone and the shallow aquifer along the 300 ft of shoreline where Sr-90 concentrations are highest. This report describes the field testing of the shallow aquifer treatment.

  4. Pacific Northwest National Laboratory Apatite Investigation at the 100-NR-2 Quality Assurance Project Plan

    SciTech Connect

    Fix, N. J.

    2008-03-28

    This Quality Assurance Project Plan provides the quality assurance requirements and processes that will be followed by staff working on the 100-NR-2 Apatite Project. The U.S. Department of Energy, Fluor Hanford, Inc., Pacific Northwest National Laboratory, and the Washington Department of Ecology agreed that the long-term strategy for groundwater remediation at 100-N would include apatite sequestration as the primary treatment, followed by a secondary treatment. The scope of this project covers the technical support needed before, during, and after treatment of the targeted subsurface environment using a new high-concentration formulation.

  5. PNNL Apatite Investigation at 100-NR-2 Quality Assurance Project Plan

    SciTech Connect

    Fix, N. J.

    2009-04-02

    In 2004, the U.S. Department of Energy, Fluor Hanford, Inc., Pacific Northwest National Laboratory (PNNL), and the Washington Department of Ecology agreed that the long-term strategy for groundwater remediation at the 100-N Area would include apatite sequestration as the primary treatment, followed by a secondary treatment if necessary. Since then, the agencies have worked together to agree on which apatite sequestration technology has the greatest chance of reducing strontium-90 flux to the Columbia River. This Quality Assurance Project Plan provides the quality assurance requirements and processes that will be followed by staff working on the PNNL Apatite Investigation at 100-NR-2 Project. The plan is designed to be used exclusively by project staff.

  6. FIELD TEST INSTRUCTION 100-NR-2 OPERABLE UNIT DESIGN OPTIMIZATION STUDY FOR SEQUESTRATION OF SR-90 SATURATED ZONE APATITE PERMEABLE REACTIVE BARRIER EXTENSION

    SciTech Connect

    BOWLES NA

    2010-10-06

    The objective of this field test instruction is to provide technical guidance for aqueous injection emplacement of an extension apatite permeable reactive barrier (PRE) for the sequestration of strontium-90 (Sr-90) using a high concentration amendment formulation. These field activities will be conducted according to the guidelines established in DOE/RL-2010-29, 100-NR-2 Design Optimization Study, hereafter referred to as the DOS. The DOS supports the Federal Facility Agreement Consent Order (EPA et al., 1989), Milestone M-16-06-01, and 'Complete Construction of a Permeable Reactive Barrier at 100-N.' Injections of apatite precursor chemicals will occur at an equal distance intervals on each end of the existing PRE to extend the PRB from the existing 91 m (300 ft) to at least 274 m (900 ft). Field testing at the 100-N Area Apatite Treatability Test Site, as depicted on Figure 1, shows that the barrier is categorized by two general hydrologic conceptual models based on overall well capacity and contrast between the Hanford and Ringold hydraulic conductivities. The upstream portion of the original barrier, shown on Figure 1, is characterized by relatively low overall well specific capacity. This is estimated from well development data and a lower contrast in hydraulic conductivity between the Hanford formation and Ringold Formations. Comparison of test results from these two locations indicate that permeability contrast between the Hanford formation and Ringold Formation is significantly less over the upstream one-third of the barrier. The estimated hydraulic conductivity for the Hanford formation and Ringold Formation over the upstream portion of the barrier based on observations during emplacement of the existing 91 m (300 ft) PRB is approximately 12 and 10 m/day (39 and 32 ft/day), respectively (PNNL-17429). However, these estimates should be used as a rough guideline only, as significant variability in hydraulic conductivity is likely to be observed in the

  7. 100-NR-2 Apatite Treatability Test: An update on Barrier Performance

    SciTech Connect

    Fritz, Brad G.; Vermeul, Vincent R.; Fruchter, Jonathan S.; Szecsody, James E.; Williams, Mark D.

    2011-05-01

    This report updates a previous report covering the performance of a permeable reactive barrier installed at 100N. In this report we re-evaluate the results after having an additional year of performance monitoring data to incorporate.

  8. Hanford Apatite Treatability Test Report Errata: Apatite Mass Loading Calculation

    SciTech Connect

    Szecsody, James E.; Vermeul, Vincent R.; Williams, Mark D.; Truex, Michael J.

    2014-05-19

    The objective of this errata report is to document an error in the apatite loading (i.e., treatment capacity) estimate reported in previous apatite treatability test reports and provide additional calculation details for estimating apatite loading and barrier longevity. The apatite treatability test final report (PNNL-19572; Vermeul et al. 2010) documents the results of the first field-scale evaluation of the injectable apatite PRB technology. The apatite loading value in units of milligram-apatite per gram-sediment is incorrect in this and some other previous reports. The apatite loading in units of milligram phosphate per gram-sediment, however, is correct, and this is the unit used for comparison to field core sample measurements.

  9. Project Work Plan 100-N Area Strontium-90 Treatability Demonstration Project: Phytoremediation Along the 100-N Columbia River Riparian Zone

    SciTech Connect

    Ainsworth, Calvin C.

    2006-04-30

    The 100-N Area Innovative Treatment and Remediation Demonstration (ITRD) identified phyto¬remediation as a potential technology both for the removal of 90Sr from the soil of the riparian zone and as a filter for groundwater along the Columbia River. Recent greenhouse and growth chamber studies have demonstrated the viability of phytoextraction to remove 90Sr from this area’s soil/water; in conjunction with monitored natural attenuation and an apatite barrier the process would make an effective treatment for remediation of the 100-N Area 90Sr plume. All activities associated with the 100-NR-1 and 100-NR-2 Operable Units of the Hanford 100-N Area have had, and continue to have, significant regulatory and stakeholder participation. Beginning in 1998 with the ITRD process, presentations to the ITRD TAG were heavily attended by EPA, Washington State Department of Ecology, and stakeholders. In addition, three workshops have been held to receive regulatory and stakeholder feedback on monitored natural attenuation, the apatite barrier, and phytoremediation; these were held in Richland in August 2003, December 2004, and August 2005. The apatite injection treatability test plan (DOE 2005) describes phytoremediation as a technology to be evaluated during the March 2008 evaluation milestone as described in the Tri-Party Agreement change request (M-16-06-01 Change Control Form). If, during this evaluation milestone, phytoremediation is favorably evaluated it would be incorporated into the treatability test plan. The phytoremediation treatability test described in this proposal is strongly supported by the Washington State Department of Ecology.

  10. Annual Summary Report Calendar Year 2000 for the 100-HR-3, 100-KR-4, and 100-NR-2 Operable Units and Pump-and-Treat Operations

    SciTech Connect

    G. B. Mitchem

    2001-08-22

    This annual progress and performance evaluation report discusses the groundwater remedial actions in the 100 Area, including the interim actions at the 100-HR-3 and 100-KR-4 Operable Units, and also discusses the expedited response action in the 100-NR-2 operable unit.

  11. TREATABILITY DATABASE DESCRIPTION

    EPA Science Inventory

    The Drinking Water Treatability Database (TDB) presents referenced information on the control of contaminants in drinking water. It allows drinking water utilities, first responders to spills or emergencies, treatment process designers, research organizations, academics, regulato...

  12. Soil washing treatability study

    SciTech Connect

    Krstich, M.

    1995-12-01

    Soil washing was identified as a viable treatment process option for remediating soil at the FEMP Environmental Management Project (FEMP). Little information relative to the specific application and potential effectiveness of the soil washing process exists that applies to the types of soil at the FEMP. To properly evaluate this process option in conjunction with the ongoing FEMP Remedial Investigation/Feasibility Study (RI/FS), a treatability testing program was necessary to provide a foundation for a detailed technical evaluation of the viability of the process. In August 1991, efforts were initiated to develop a work plan and experimental design for investigating the effectiveness of soil washing on FEMP soil. In August 1992, the final Treatability Study Work Plan for Operable Unit 5: Soil Washing (DOE 1992) was issued. This document shall be referenced throughout the remainder of this report as the Treatability Study Work Plan (TSWP). The purpose of this treatability study was to generate data to support initial screening and the detailed analysis of alternatives for the Operable Unit 5 FS.

  13. The lunar apatite paradox.

    PubMed

    Boyce, J W; Tomlinson, S M; McCubbin, F M; Greenwood, J P; Treiman, A H

    2014-04-25

    Recent discoveries of water-rich lunar apatite are more consistent with the hydrous magmas of Earth than the otherwise volatile-depleted rocks of the Moon. Paradoxically, this requires H-rich minerals to form in rocks that are otherwise nearly anhydrous. We modeled existing data from the literature, finding that nominally anhydrous minerals do not sufficiently fractionate H from F and Cl to generate H-rich apatite. Hydrous apatites are explained as the products of apatite-induced low magmatic fluorine, which increases the H/F ratio in melt and apatite. Mare basalts may contain hydrogen-rich apatite, but lunar magmas were most likely poor in hydrogen, in agreement with the volatile depletion that is both observed in lunar rocks and required for canonical giant-impact models of the formation of the Moon.

  14. [Treatable dementia syndromes].

    PubMed

    Biedert, S; Schreiter, U; Alm, B

    1987-03-01

    Dementia--a syndrome of acquired intellectual deterioration--is an etiologically non-specific condition which is permanent, progressive, or reversible. In the evaluation of demented patients, a careful exposure history will determine the possible role of drugs, metals, or toxins. The physical examination may reveal focal deficits in cases of intracranial mass lesions and spasticity or ataxia of the lower limbs if hydrocephalus is present. Coexistance of dementia and peripheral neuropathy usually indicates a toxic or metabolic disorder. Asterixis, myoclonus, and postural tremor are common in toxic-metabolic dementias, while resting tremor, choreoathetosis, and rigidity occur in progressive extrapyramidal disorders. EEG is focally abnormal in cases of cerebral mass lesions and exhibits generalized slowing in toxic-metabolic encephalopathies. CT will aid in the identification of hydrocephalus, subdural hematomas, and intracranial mass lesions. A thorough laboratory evaluation including complete blood count, erythrocyte sedimentation rate, electrolytes, blood urea nitrogen and blood sugar, liver and thyroid tests, calcium and phosphorus levels, B12 and folate levels, serum copper and ceruloplasmin, VDRL, chest X-ray, electrocardiogram, and lumbar puncture may demonstrate treatable disorders that are adversely affecting intellectual function. Elderly individuals are particularly susceptible to the effects of toxic or metabolic disorders, and a mild dementia might be exaggerated by relatively minor fluctuations in metabolic status. Treatable causes of dementia should be considered in all demented patients.

  15. 100-N Area Strontium-90 Treatability Demonstration Project: Phytoextraction Along the 100-N Columbia River Riparian Zone – Field Treatability Study

    SciTech Connect

    Fellows, Robert J.; Fruchter, Jonathan S.; Driver, Crystal J.; Ainsworth, Calvin C.

    2010-01-11

    Strontium-90 (90Sr) is present both in the aquifer near the river and in the vadose and riparian zones of the river’s shore at 100-NR-2. Phytoextraction of 90Sr is being considered as a potential remediation system along the riparian zone of the Columbia River. Phytoextraction would employ coyote willow (Salix exigua). Past studies have shown that willow roots share uptake mechanisms for Sr with Ca, a plant macronutrient as well as no discrimination between Sr and 90Sr. Willow 90Sr concentration ratios [CR’s; (pCi 90Sr/g dry wt. of new growth tissue)/(pCi 90Sr/g soil porewater)] were consistently greater than 65 with three-quarters of the assimilated label partitioned into the above ground shoot. Insect herbivore experiments also demonstrated no significant potential for bioaccumulation or food chain transfer from their natural activities. The objectives of this field study were three-fold: (1) to demonstrate that a viable, “managed” plot of coyote willows can be established on the shoreline of the Columbia River that would survive the same microenvironment to be encountered at the 100-NR-2 shoreline; (2) to show through engineered barriers that large and small animal herbivores can be prevented from feeding on these plants; and (3) to show that once established, the plants will provide sufficient biomass annually to support the phytoextraction technology. A field treatability demonstration plot was established on the Columbia River shoreline alongside the 100-K West water intake at the end of January 2007. The plot was delimited by a 3.05 m high chain-link fence and was approximately 10 x 25 m in size. A layer of fine mesh metal small animal screening was placed around the plot at the base of the fencing to a depth of 45 cm. A total of sixty plants were placed in six slightly staggered rows with 1-m spacing between plants. The actual plot size was 0.00461 hectare (ha). At the time of planting (March 12, 2007), the plot was located about 10 m from the

  16. Interim Report: Uranium Stabilization Through Polyphosphate Injection - 300 Area Uranium Plume Treatability Demonstration Project

    SciTech Connect

    Wellman, Dawn M.; Pierce, Eric M.; Richards, Emily L.; Butler, Bart C.; Parker, Kent E.; Glovack, Julia N.; Burton, Sarah D.; Baum, Steven R.; Clayton, Eric T.; Rodriguez, Elsa A.

    2007-07-31

    This report presents results from bench-scale treatability studies conducted under site-specific conditions to optimize the polyphosphate amendment for implementation of a field-scale technology demonstration to treat aqueous uranium within the 300 Area aquifer of the Hanford site. The general treatability testing approach consists of conducting studies with site sediment and under site conditions, in order to develop an effective chemical formulation for the polyphosphate amendments and evaluate the transport properties of these amendments under site conditions. Phosphorus-31 (31P) NMR was utilized to determine the effects of Hanford groundwater and sediment on the degradation of inorganic phosphates. Static batch tests were conducted to optimize the composition of the polyphosphate formulation for the precipitation of apatite and autunite, as well as to quantify the kinetics, loading and stability of apatite as a long-term sorbent for uranium. Dynamic column tests were used to further optimize the polyphosphate formulation for emplacement within the subsurface and the formation of autunite and apatite. In addition, dynamic testing quantified the stability of autunite and apatite under relevant site conditions. Results of this investigation provide valuable information for designing a full-scale remediation of uranium in the 300 aquifer.

  17. Drinking Water Treatability Database (Database)

    EPA Science Inventory

    The drinking Water Treatability Database (TDB) will provide data taken from the literature on the control of contaminants in drinking water, and will be housed on an interactive, publicly-available USEPA web site. It can be used for identifying effective treatment processes, rec...

  18. Challenges Associated with Apatite Remediation of Uranium in the 300 Area Aquifer

    SciTech Connect

    Wellman, Dawn M.; Fruchter, Jonathan S.; Vermeul, Vincent R.; Williams, Mark D.

    2008-05-01

    Sequestration of uranium as insoluble phosphate phases appears to be a promising alternative for treating the uranium-contaminated groundwater at the Hanford 300 Area. The proposed approach involves both the direct formation of autunite by the application of a polyphosphate mixture, as well as the formation of apatite in the aquifer as a continuing source of phosphate for long-term treatment of uranium. After a series of bench-scale tests, a field treatability test was conducted in a well at the 300 Area. The objective of the treatability test was to evaluate the efficacy of using polyphosphate injections to treat uranium-contaminated groundwater in situ. A test site consisting of an injection well and 15 monitoring wells was installed in the 300 Area near the process trenches that had previously received uranium-bearing effluents. The results indicated that while the direct formation of autunite appears to have been successful, the outcome of the apatite formation of the test was more limited. Two separate overarching issues impact the efficacy of apatite remediation for uranium sequestration within the 300 Area: 1) the efficacy of apatite for sequestering uranium under the present geochemical and hydrodynamic conditions, and 2) the formation and emplacement of apatite via polyphosphate technology. This paper summarizes these issues.

  19. Making chromosome abnormalities treatable conditions.

    PubMed

    Cody, Jannine DeMars; Hale, Daniel Esten

    2015-09-01

    Individuals affected by the classic chromosome deletion syndromes which were first identified at the beginning of the genetic age, are now positioned to benefit from genomic advances. This issue highlights five of these conditions (4p-, 5p-, 11q-, 18p-, and 18q-). It focuses on the increased in understanding of the molecular underpinnings and envisions how these can be transformed into effective treatments. While it is scientifically exciting to see the phenotypic manifestations of hemizygosity being increasingly understood at the molecular and cellular level, it is even more amazing to consider that we are now on the road to making chromosome abnormalities treatable conditions.

  20. Treatability Test Plan for 300 Area Uranium Stabilization through Polyphosphate Injection

    SciTech Connect

    Vermeul, Vincent R.; Williams, Mark D.; Fritz, Brad G.; Mackley, Rob D.; Mendoza, Donaldo P.; Newcomer, Darrell R.; Rockhold, Mark L.; Williams, Bruce A.; Wellman, Dawn M.

    2007-06-01

    The U.S. Department of Energy has initiated a study into possible options for stabilizing uranium at the 300 Area using polyphosphate injection. As part of this effort, PNNL will perform bench- and field-scale treatability testing designed to evaluate the efficacy of using polyphosphate injections to reduced uranium concentrations in the groundwater to meet drinking water standards (30 ug/L) in situ. This technology works by forming phosphate minerals (autunite and apatite) in the aquifer that directly sequester the existing aqueous uranium in autunite minerals and precipitates apatite minerals for sorption and long term treatment of uranium migrating into the treatment zone, thus reducing current and future aqueous uranium concentrations. Polyphosphate injection was selected for testing based on technology screening as part of the 300-FF-5 Phase III Feasibility Study for treatment of uranium in the 300-Area.

  1. DOE Waste Treatability Group Guidance

    SciTech Connect

    Kirkpatrick, T.D.

    1995-01-01

    This guidance presents a method and definitions for aggregating U.S. Department of Energy (DOE) waste into streams and treatability groups based on characteristic parameters that influence waste management technology needs. Adaptable to all DOE waste types (i.e., radioactive waste, hazardous waste, mixed waste, sanitary waste), the guidance establishes categories and definitions that reflect variations within the radiological, matrix (e.g., bulk physical/chemical form), and regulated contaminant characteristics of DOE waste. Beginning at the waste container level, the guidance presents a logical approach to implementing the characteristic parameter categories as part of the basis for defining waste streams and as the sole basis for assigning streams to treatability groups. Implementation of this guidance at each DOE site will facilitate the development of technically defined, site-specific waste stream data sets to support waste management planning and reporting activities. Consistent implementation at all of the sites will enable aggregation of the site-specific waste stream data sets into comparable national data sets to support these activities at a DOE complex-wide level.

  2. Amenable Treatable Severe Pediatric Epilepsies.

    PubMed

    Pearl, Phillip L

    2016-05-01

    Vitamin-dependent epilepsies and multiple metabolic epilepsies are amenable to treatment that markedly improves the disease course. Knowledge of these amenably treatable severe pediatric epilepsies allows for early identification, testing, and treatment. These disorders present with various phenotypes, including early onset epileptic encephalopathy (refractory neonatal seizures, early myoclonic encephalopathy, and early infantile epileptic encephalopathy), infantile spasms, or mixed generalized seizure types in infancy, childhood, or even adolescence and adulthood. The disorders are presented as vitamin responsive epilepsies such as pyridoxine, pyridoxal-5-phosphate, folinic acid, and biotin; transportopathies like GLUT-1, cerebral folate deficiency, and biotin thiamine responsive disorder; amino and organic acidopathies including serine synthesis defects, creatine synthesis disorders, molybdenum cofactor deficiency, and cobalamin deficiencies; mitochondrial disorders; urea cycle disorders; neurotransmitter defects; and disorders of glucose homeostasis. In each case, targeted intervention directed toward the underlying metabolic pathophysiology affords for the opportunity to significantly effect the outcome and prognosis of an otherwise severe pediatric epilepsy. PMID:27544473

  3. 118-B-1 excavation treatability test plan

    SciTech Connect

    Not Available

    1994-07-01

    The Hanford 118-B-1 Burial Ground Treatability Study has been required by milestone change request {number_sign}M-15-93-04, dated September 30, 1993. The change request requires that a treatability test be conducted at the 100-B Area to obtain additional engineering information for remedial design of burial grounds receiving waste from 100 Area removal actions. This treatability study has two purposes: (1) to support development of the Proposed Plan (PP) and Record of Decision (ROD), which will identify the approach to be used for burial ground remediation, and (2) to provide specific engineering information for receiving waste generated from the 100 Area removal actions. Data generated from this test also will provide critical performance and cost information necessary for remedy evaluation in the detailed analysis of alternatives during preparation of the focused feasibility study (FFS). This treatability testing supports the following 100 Area alternatives: (1) excavation and disposal, and (2) excavation, sorting, (treatment), and disposal.

  4. GUIDE FOR CONDUCTING TREATABILITY STUDIES UNDER CERCLA

    EPA Science Inventory

    Systematically conducted, well-documented treatability studies are an important component of the removal process, remedial investigation/ feasibility study (RI/FS) process and the remedial design/remedial action (RD/RA) process under the Comprehensive Environmental Response...

  5. LABORATORY SCALE STEAM INJECTION TREATABILITY STUDIES

    EPA Science Inventory

    Laboratory scale steam injection treatability studies were first developed at The University of California-Berkeley. A comparable testing facility has been developed at USEPA's Robert S. Kerr Environmental Research Center. Experience has already shown that many volatile organic...

  6. DEEP VADOSE ZONE TREATABILITY TEST PLAN

    SciTech Connect

    GB CHRONISTER; MJ TRUEX

    2009-07-02

    {sm_bullet} Treatability test plan published in 2008 {sm_bullet} Outlines technology treatability activities for evaluating application of in situ technologies and surface barriers to deep vadose zone contamination (technetium and uranium) {sm_bullet} Key elements - Desiccation testing - Testing of gas-delivered reactants for in situ treatment of uranium - Evaluating surface barrier application to deep vadose zone - Evaluating in situ grouting and soil flushing

  7. 100 area excavation treatability test plan

    SciTech Connect

    Not Available

    1993-05-01

    This test plan documents the requirements for a treatability study on field radionuclide analysis and dust control techniques. These systems will be used during remedial actions involving excavation. The data from this treatability study will be used to support the feasibility study (FS) process. Development and screening of remedial alternatives for the 100 Area, using existing data, have been completed and are documented in the 100 Area Feasibility Study, Phases 1 and 2 (DOE-RL 1992a). Based on the results of the FS, the Treatability Study Program Plan (DOE-RL 1992b) identifies and prioritizes treatability studies for the 100 Area. The data from the treatability study program support future focused FS, interim remedial measures (IRM) selection, operable unit final remedy selection, remedial design, and remedial actions. Excavation is one of the high-priority, near-term, treatability study needs identified in the program plan (DOE-RL 1992b). Excavation of contaminated soils and buried solid wastes is included in several of the alternatives identified in the 100 Area FS. Although a common activity, excavation has only been used occasionally at the Hanford Site for waste removal applications.

  8. Evaporative oxidation treatability test report

    SciTech Connect

    1995-04-01

    In 1992, Congress passed the Federal Facilities Compliance Act that requires the U.S. Department of Energy (DOE) to treat and dispose of its mixed waste in accordance with the Resource Conservation and Recovery Act (RCRA) land disposal restrictions (LDRs). In response to the need for mixed-waste treatment capacity where available off-site commercial treatment facilities do not exist or cannot be used, the DOE Albuquerque Operations Office (DOE-AL) organized a Treatment Selection Team to match mixed wastes with treatment options and develop a strategy for treatment of its mixed wastes. DOE-AL manages operations at nine sites with mixed-waste inventories. The Treatment Selection Team determined a need to develop mobile treatment capacity to treat wastes at the sites where the wastes are generated. Treatment processes used for mixed waste not only must address the hazardous component (i.e., meet LDRs) but also must contain the radioactive component in a form that allows final disposal while protecting workers, the public, and the environment. On the basis of recommendations of the Treatment Selection Team, DOE-AL assigned projects to the sites to bring mixed-waste treatment capacity on-line. The three technologies assigned to the DOE Grand Junction Projects Office (GJPO) are evaporative oxidation, thermal desorption, and treated wastewater evaporation. Rust Geotech, the DOE-GJPO prime contractor, was assigned to design and fabricate mobile treatment units (MTUs) for these three technologies and to deliver the MTUs to selected DOE-AL sites. To conduct treatability tests at the GJPO, Rust leased a pilot-scale evaporative oxidation unit from the Clemson Technical Center (CTC), Anderson, South Carolina. The purpose of this report is to document the findings and results of tests performed using this equipment.

  9. Treatability data base, version 5.0

    SciTech Connect

    Shaul, G.M.; Waterman, J.D.

    1995-10-01

    The purpose of the Risk Reduction Engineering Laboratory Treatability Data Base is to provide a thorough review of the effectiveness of proven treatment technologies in the removal/destruction of chemicals in various types of media including, but not limited to, municipal and industrial wastewater, drinking water, groundwater, soil, debris, sludge, and sediment. The database contains 1,217 chemical compounds and over 15,800 sets of treatability data. The chemicals contained in the database are often those regulated under the Clean Water Act, Safe Drinking Water Act, Resource Conservation and Recovery Act, Toxic Substances Control Act, Superfund Amendments and Reauthorization Act, and other environmental laws enacted by Congress. For each chemical, the database includes: physical/chemical properties, aqueous and solid treatability data, Freundlich isotherm data, other environmental database information sources, and data references including a reference abstract. The physical/chemical properties included are those most routinely used, such as molecular weight, boiling point, melting point, etc. The treatability data summarize the treatment technologies used to treat the specific chemical; the type of waste/wastewater treated; the size of the study/plant; and the treatment efficiency achieved. Data sorting capabilities allow for comparison of treatability data. In addition, each data set is referenced to sources of information, operational information on processes sampled and quality-coded based upon analytical methods and reported quality assurance.

  10. In-Situ Uranium Stabilization Through Polyphosphate Injection: Pilot-Scale Treatability Test at the 300 Area, Hanford Site - 8187

    SciTech Connect

    Vermeul, Vince R.; Fruchter, Jonathan S.; Fritz, Brad G.; Mackley, Rob D.; Wellman, Dawn M.; Williams, Mark D.

    2008-06-02

    This paper describes the pilot-scale treatability test that was conducted to evaluate the efficacy of using a polyphosphate injection approach to treat uranium-contaminated groundwater in situ within the 300 Area aquifer at the Hanford Site in Richland, Washington. Primary test objectives were to assess 1) direct treatment of available uranium contributing to the groundwater plume through precipitation of the uranyl phosphate mineral autunite, and 2) emplacement of secondary-treatment capacity via precipitation of the calcium phosphate mineral apatite, which acts as a long-term sorbent for uranium.

  11. SUPERFUND TREATABILITY CLEARINGHOUSE: COMPOSITING OF EXPLOSIVES

    EPA Science Inventory

    This treatability study was conducted by Atlantic Research Corporation for the U.S. Army Toxic and Hazardous Material Agency. The objective of this bench-scale study was to determine the extent to which TNT and RDX concentrations were reduced by composting for a six week peri...

  12. THE DRINKING WATER TREATABILITY DATABASE (Slides)

    EPA Science Inventory

    The Drinking Water Treatability Database (TDB) assembles referenced data on the control of contaminants in drinking water, housed on an interactive, publicly-available, USEPA web site (www.epa.gov/tdb). The TDB is of use to drinking water utilities, treatment process design engin...

  13. THE DRINKING WATER TREATABILITY DATABASE (Conference Paper)

    EPA Science Inventory

    The Drinking Water Treatability Database (TDB) assembles referenced data on the control of contaminants in drinking water, housed on an interactive, publicly-available, USEPA web site (www.epa.gov/tdb). The TDB is of use to drinking water utilities, treatment process design engin...

  14. Factors controlling sulfur concentrations in volcanic apatite

    USGS Publications Warehouse

    Peng, G.; Luhr, J.F.; McGee, J.J.

    1997-01-01

    Apatite crystals from two types of samples were analyzed by electron microprobe for 15 major and trace elements: (1) apatite in H2O- and S-saturated experimental charges of the 1982 El Chicho??n trachyandesite and (2) apatite in volcanic rocks erupted from 20 volcanoes. The SO3 contents of the experimental apatite increase with increasing oxygen fugacity (fo2), from ???0.04 wt% in reduced charges buffered by fayalite-magnetite-quartz (FMQ), to 1.0-2.6 wt% in oxidized charges buffered by manganosite-hausmanite (MNH) or magnetite-hematite (MTH). The SO3 contents of MNH- and MTH-buffered apatite also generally increase with increasing pressure from 2 to 4 kbar and decreasing temperature from 950 to 800??C. The partition coefficient for SO3 between apatite and oxidized melt increases with decreasing temperature but appears to be independent of pressure. Apatites in volcanic rocks show a wide range of SO3 contents (<0.04 to 0.63 wt%). Our sample set includes one group known to contain primary anhydrite and a second group inferred to have been free of primary anhydrite. No systematic differences in apatite S contents are observed between these two groups. Our study was initiated to define the factors controlling S contents in apatite and to evaluate the hypothesis that high S contents in apatite could be characteristic of S-rich anhydrite-bearing magmas such as those erupted from El Chicho??n in 1982 and Pinatubo in 1991. This hypothesis is shown to be invalid, probably chiefly a consequence of the slow intra-crystaline diffusion that limits re-equilibration between early formed apatite and the evolving silicate melt. Contributing factors include early crystallization of most apatite over a relatively small temperature interval, common late-stage magmatic enrichment of S, progressive oxidation during magmatic evolution, and strong controls on S contents in apatite exerted fo2, temperature, and pressure.

  15. 118-B-1 excavation treatability test procedures

    SciTech Connect

    Frain, J.M.

    1994-08-01

    This treatability study has two purposes: to support development of the approach to be used for burial ground remediation, and to provide specific engineering information for the design of burial grounds receiving waste generated from the 100 Area removal actions. Data generated from this test will also provide performance and cost information necessary for detailed analysis of alternatives for burial ground remediation. Further details on the test requirements, milestones and data quality objectives are described in detail in the 118-B-1 Excavation Treatability Test Plan (DOE/RL-94-43). These working procedures are intended for use by field personnel to implement the requirements of the milestone. A copy of the detailed Test Plan will be kept on file at the on-site field support trailer, and will be available for review by field personnel.

  16. Informatics guided Search for Magnetic Apatites

    NASA Astrophysics Data System (ADS)

    Balachandran, Prasanna V.; Lookman, Turab

    2015-03-01

    Materials with apatite crystal structure have applications ranging from biomaterials to electrolytes for solid oxide fuel cells. Their chemical flexibility and structural diversity provide a fertile ground to tune functionalities as potential candidates for many applications. However, magnetic apatites are rare. In this work, we use machine learning methods to rapidly screen a vast chemical space and identify novel apatite compositions with magnetic ions. We first construct a database of known materials from surveying the experimental literature. We then augment the database with features that capture the trends in geometry and bonding characteristics of apatites. Supervised classification learning form the basis of our machine learning approach through which we uncover design rules that enable prediction of potentially stable magnetic apatite compositions, prior to experimental synthesis. Finally, we validate our predictions using density functional theory calculations.

  17. An Injectable Apatite Permeable Reactive Barrier for In Situ 90Sr Immobilization

    SciTech Connect

    Vermeul, Vincent R.; Szecsody, James E.; Fritz, Brad G.; Williams, Mark D.; Moore, Robert C.; Fruchter, Jonathan S.

    2014-04-16

    An injectable permeable reactive barrier (PRB) technology was developed to sequester 90Sr in groundwater through the in situ formation of calcium-phosphate mineral phases, specifically apatite that incorporates 90Sr into the chemical structure. An integrated, multi-scale development and testing approach was used that included laboratory bench-scale experiments, an initial pilot-scale field test, and the emplacement and evaluation of a 300-ft-long treatability-test-scale PRB. Standard groundwater wells were used for emplacement of the treatment zone, allowing treatment of contaminants too deep below ground surface for trench-and-fill type PRB technologies. The apatite amendment formulation uses two separate precursor solutions, one containing a Ca-citrate complex and the other a Na-phosphate solution, to form apatite precipitate in situ. Citrate is needed to keep calcium in solution long enough to achieve a more uniform and areally extensive distribution of precipitate formation. In the summer of 2008, the apatite PRB technology was applied as a 91-m (300-ft) -long permeable reactive barrier on the downgradient edge of a 90Sr plume beneath the Hanford Site in Washington State. The technology was deployed to reduce 90Sr flux discharging to the Columbia River. Performance assessment monitoring data collected to date indicate the barrier is meeting performance objectives. The average reduction in 90Sr concentrations at four downgradient compliance monitoring locations was 95% relative to the high end of the baseline range approximately 1 year after treatment, and continues to meet remedial objectives more than 4 years after treatment.

  18. U-Pb Ages of Lunar Apatites

    NASA Technical Reports Server (NTRS)

    Vaughan, J.; Nemchin, A. A.; Pidgeon, R. T.; Meyer, Charles

    2006-01-01

    Apatite is one of the minerals that is rarely utilized in U-Pb geochronology, compared to some other U-rich accessory phases. Relatively low U concentration, commonly high proportion of common Pb and low closure temperature of U-Pb system of apatite inhibit its application as geochronological tool when other minerals such as zircon are widely available. However, zircon appear to be restricted to certain type of lunar rocks, carrying so called KREEP signature, whereas apatite (and whitlockite) is a common accessory mineral in the lunar samples. Therefore, utilizing apatite for lunar chronology may increase the pool of rocks that are available for U-Pb dating. The low stability of U-Pb systematics of apatite may also result in the resetting of the system during meteoritic bombardment, in which case apatite may provide an additional tool for the study of the impact history of the Moon. In order to investigate these possibilities, we have analysed apatites and zircons from two breccia samples collected during the Apollo 14 mission. Both samples were collected within the Fra Mauro formation, which is interpreted as a material ejected during the impact that formed the Imbrium Basin.

  19. Cyanide analyses for risk and treatability assessments

    SciTech Connect

    MacFarlane, I.D.; Elseroad, H.J.; Pergrin, D.E.; Logan, C.M.

    1994-12-31

    Cyanide, an EPA priority pollutant and target analyte, is typically measured as total. However, cyanide complexation, information which is not acquired through total cyanide analysis, is often a driver of cyanide toxicity and treatability. A case study of a former manufacture gas plant (MGP) is used to demonstrate the usability of various cyanide analytical methods for risk and treatability assessments. Several analytical methods, including cyanide amenable to chlorination and weak acid dissociable cyanide help test the degree of cyanide complexation. Generally, free or uncomplexed cyanide is more biologically available, toxic, and reactive than complexed cyanide. Extensive site testing has shown that free and weakly dissociable cyanide composes only a small fraction of total cyanide as would be expected from the literature, and that risk assessment will be more realistic considering cyanide form. Likewise, aqueous treatment for cyanide can be properly tested if cyanide form is accounted for. Weak acid dissociable cyanide analyses proved to be the most reliable (and potentially acceptable) cyanide method, as well as represent the most toxic and reactive cyanide forms.

  20. Magmatic Volatile Histories From Apatite Phenocrysts

    NASA Astrophysics Data System (ADS)

    Boyce, J. W.; Hervig, R. L.

    2008-12-01

    Apatite phenocrysts contain as part of their structure all the major magmatic volatile elements (H, C, F, S, and Cl). For this reason we have explored the potential for apatite to record magmatic volatile histories [1], and compared the volatile record in apatite with that derived from melt inclusions [2]. Apatite has been observed at many central American volcanoes including Irazu, Arenal, Concepcion, Fuego, and Pacaya, and therefore there is great potential to extend this record, and use it to understand local and regional complexities in magmatic volatile behavior. Our results from Volcan Irazu (Costa Rica) are the first such measurements from the Central American volcanic arc. At Irazu, apatite [2] and melt inclusions [3] from the 1723 eruption have high to moderate H and Cl contents as compared with the 1963 apatite and melt inclusions. Both individual apatite crystals and populations of crystals from each sample are heterogeneous with respect to H, F, and Cl. Such heterogeneities could only be preserved for short periods of time (days to years) in the face of diffusive equilibration. In addition, core to rim volatile variations place relative temporal constraints on the processes affecting volatiles, and allow us to differentiate between monotonic evolution of a single magma batch and processes involving separate components. Using estimated partition coefficients, we can model melt volatile chemistry based on the apatite volatile data. The result of such modeling is that melt inclusions and apatite from the same hand samples yield identical, nonlinear trends in ternary H-F-Cl space, trends that - when combined with the relative timing given by volatile stratigraphy within zoned apatites - are consistent with late stage magma mixing between components with strikingly different volatile chemistry. References 1. Boyce, J.W. and R.L. Hervig, Magmatic degassing histories from apatite volatile stratigraphy. Geology, 2008. 36(1): p. 63. 2. Boyce, J.W. and R

  1. Apatite-Melt Partitioning at 1 Bar: An Assessment of Apatite-Melt Exchange Equilibria Resulting from Non-Ideal Mixing of F and Cl in Apatite

    NASA Technical Reports Server (NTRS)

    McCubbin, F. M.; Ustunisik, G.; Vander Kaaden, K. E.

    2016-01-01

    The mineral apatite [Ca5(PO4)3(F,Cl,OH)] is present in a wide range of planetary materials. Due to the presence of volatiles within its crystal structure (X-site), many recent studies have attempted to use apatite to constrain the volatile contents of planetary magmas and mantle sources. In order to use the volatile contents of apatite to precisely determine the abundances of volatiles in coexisting silicate melt or fluids, thermodynamic models for the apatite solid solution and for the apatite components in multi-component silicate melts and fluids are required. Although some thermodynamic models for apatite have been developed, they are incomplete. Furthermore, no mixing model is available for all of the apatite components in silicate melts or fluids, especially for F and Cl components. Several experimental studies have investigated the apatite-melt and apatite-fluid partitioning behavior of F, Cl, and OH in terrestrial and planetary systems, which have determined that apatite-melt partitioning of volatiles are best described as exchange equilibria similar to Fe-Mg partitioning between olivine and silicate melt. However, McCubbin et al. recently reported that the exchange coefficients may vary in portions of apatite compositional space where F, Cl, and OH do not mix ideally in apatite. In particular, solution calorimetry data of apatite compositions along the F-Cl join exhibit substantial excess enthalpies of mixing. In the present study, we conducted apatite-melt partitioning experiments in evacuated, sealed silica-glass tubes at approximately 1 bar and 950-1050 degrees Centigrade on a synthetic Martian basalt composition equivalent to the basaltic shergottite Queen Alexandria Range (QUE) 94201. These experiments were conducted dry, at low pressure, to assess the effects of temperature and apatite composition on the partitioning behavior of F and Cl between apatite and basaltic melt along the F-Cl apatite binary join, where there is non-ideal mixing of F and Cl

  2. Water-mediated structuring of bone apatite.

    PubMed

    Wang, Yan; Von Euw, Stanislas; Fernandes, Francisco M; Cassaignon, Sophie; Selmane, Mohamed; Laurent, Guillaume; Pehau-Arnaudet, Gérard; Coelho, Cristina; Bonhomme-Coury, Laure; Giraud-Guille, Marie-Madeleine; Babonneau, Florence; Azaïs, Thierry; Nassif, Nadine

    2013-12-01

    It is well known that organic molecules from the vertebrate extracellular matrix of calcifying tissues are essential in structuring the apatite mineral. Here, we show that water also plays a structuring role. By using solid-state nuclear magnetic resonance, wide-angle X-ray scattering and cryogenic transmission electron microscopy to characterize the structure and organization of crystalline and biomimetic apatite nanoparticles as well as intact bone samples, we demonstrate that water orients apatite crystals through an amorphous calcium phosphate-like layer that coats the crystalline core of bone apatite. This disordered layer is reminiscent of those found around the crystalline core of calcified biominerals in various natural composite materials in vivo. This work provides an extended local model of bone biomineralization. PMID:24193662

  3. A Systematic Description of Apatite Frameworks

    NASA Astrophysics Data System (ADS)

    White, T.

    2006-05-01

    Apatites of various chemistries are potentially important in chemical synthesis, clean energy and environmental remediation. The so-called 'lacunary' apatites are prospective fuel cell electrolytes, while silver analogues are potential photocatalysts, and radiation resistant silicate apatites can retain nuclear wastes. Although apatites have one-dimensional channels, as distinct from the three-dimensional channels in classic zeolites, they do display several zeolitic features including: a framework which can be tuned to accommodate different tunnel contents; an ability to accept large cations of different valance through the introduction of framework counter ions; and reversible ion exchange for some anions and cations. Most recently, it has been recognized, in both natural and synthetic materials, that intergrowth of tunnels of different size at the nanoscale is possible, a feature with important technology performance implications. This paper describes a new approach for the structural derivation of apatites from an idealized prototype that correlates chemistry and tunnel geometry, and in so doing, permits the design of new apatites and prediction of their properties.

  4. In Situ Vitrification Treatability Study Work Plan

    SciTech Connect

    Charboneau, B.L.; Landon, J.L.

    1989-03-01

    The Buried Waste Program was established in October, 1987 to accelerate the studies needed to develop a recommended long-term management plan for the buried mixed waste at the Radioactive Waste Management Complex at the Idaho National Engineering Laboratory. The In Situ Vitrification Project is being conducted in a Comprehensive Environmental Response, Compensation, and Liability Act Feasibility Study format to identify methods for the long-term management of the mixed waste buried. This In Situ Vitrification Treatability Study Work Plan gives a brief description of the site, work breakdown structure, and project organization: the in situ vitrification technology; the purpose of the tests and demonstrations; and the equipment and materials required for the tests and demonstration. 5 refs., 6 figs., 3 tabs.

  5. SOIL WASHING TREATABILITY TESTS FOR PESTICIDE- CONTAMINATED SOIL

    EPA Science Inventory

    The 1987 Sand Creek Operable Unit 5 record of decision (ROD) identified soil washing as the selected technology to remediate soils contaminated with high levels of organochlorine pesticides, herbicides, and metals. Initial treatability tests conducted to assess the applicability...

  6. Treatability Test Plan for an In Situ Biostimulation Reducing Barrier

    SciTech Connect

    Truex, Michael J.; Vermeul, Vince R.; Long, Philip E.; Brockman, Fred J.; Oostrom, Mart; Hubbard, Susan; Borden, Robert C.; Fruchter, Jonathan S.

    2007-07-21

    This treatability test plan supports a new, integrated strategy to accelerate cleanup of chromium in the Hanford 100 Areas. This plan includes performing a field-scale treatability test for bioreduction of chromate, nitrate, and dissolved oxygen. In addition to remediating a portion of the plume and demonstrating reduction of electron acceptors in the plume, the data from this test will be valuable for designing a full-scale bioremediation system to apply at this and other chromium plumes at Hanford.

  7. Formation of apatite-collagen complexes.

    PubMed

    Doi, Y; Horiguchi, T; Moriwaki, Y; Kitago, H; Kajimoto, T; Iwayama, Y

    1996-05-01

    An apatite-collagen complex was prepared in calcium beta-glycerophosphate solutions at pH 9.0 and 37 degrees C with the purpose of developing new bone substitutes that more closely resemble bone than currently available materials. Reconstituted type I collagen as well as sheet collagen were crosslinked in the presence of alkaline phosphatase and egg-yolk phosvitin. The crosslinked collagens were immersed in daily-renewed calcium beta-glycerophosphate solutions for 2 and 4 weeks to induce the deposition of apatite on the collagen fibers. After 2 weeks of reaction, for example, apatites deposited approximately two times the crosslinked collagen in weight. With reconstituted collagen, the complex showed some elasticity but no apatite was visually observed to detach under deformation with fingers and forceps. The complex, moreover, did not disintegrate when immersed in saline or animal blood. Nevertheless, the complex resorbed with no evidence of cytotoxicity when implanted in muscle tissues. These findings suggest that the apatite-collagen complex prepared would be useful as bone substitutes, especially for periodontal osseous lesion repair and alveolar ridge augmentation. PMID:8731148

  8. The volatile content of Vesta: Clues from apatite in eucrites

    NASA Astrophysics Data System (ADS)

    Sarafian, Adam Robert; Roden, Michael F.; PatiñO-Douce, Alberto E.

    2013-11-01

    Apatite was analyzed by electron microprobe in 3 cumulate and 10 basaltic eucrites. Eucritic apatite is fluorine-rich with minor chlorine and hydroxyl (calculated by difference). We confirmed the hydroxyl content by measuring hydroxyl directly in apatites from three representative eucrites using secondary ionization mass spectroscopy. Overall, most eucritic apatites resemble fluorine-rich lunar mare apatites, but intriguing OH- and Cl-rich apatites suggest a role for water and/or hydrothermal fluids in the Vestan interior or on other related differentiated asteroids. Most late-stage apatite found in mesostasis has little hydroxyl or chlorine and is thought to have crystallized from a degassed magma; however, several apatites exhibit atypical compositions and/or textural characteristics. For example, the isotopically anomalous basaltic eucrite Pasamonte has apatite in the mesostasis with significant OH. Apatites in Juvinas also have significant OH and occur as veinlets crosscutting silicates. Euhedral apatites in the Moore County cumulate eucrite occur as inclusions in pyroxene and are also hydroxyl-rich (0.62 wt% OH). The OH was confirmed by SIMS analysis and this apatite clearly points to the presence of water, at least locally, in the Vestan interior. Portions of Elephant Moraine (EET) 90020 have large and abundant apatites, which may be the product of apatite accumulation in a zone of melt-rock reaction. Relatively chlorine-rich apatites occur in basaltic eucrite Graves Nunataks (GRA) 98098 (approximately 1 wt% Cl). Particularly striking is the compositional similarity between apatite in GRA 98098 and apatites in lunar KREEP, which may indicate the presence of residual magmas from an asteroid-wide magma ocean on Vesta.

  9. Ultrastructural analyses of nanoscale apatite biomimetically grown on organic template.

    PubMed

    Hong, S I; Lee, K H; Outslay, M E; Kohn, D H

    2008-02-01

    The ultrastructure of nanoscale apatite biomimetically formed on an organic template from a supersaturated mineralizing solution was studied to examine the morphological and crystalline arrangement of mineral apatites. Needle-shaped apatite crystal plates with a size distribution of ~100 to ~1000 nm and the long axis parallel to the c axis ([002]) were randomly distributed in the mineral films. Between these randomly distributed needle-shaped apatite crystals, amorphous phases and apatite crystals (~20-40 nm) with the normal of the grains quasi-perpendicular to the c axis were observed. These observations suggest that the apatite film is an interwoven structure of amorphous phases and apatite crystals with various orientations. The mechanisms underlying the shape of the crystalline apatite plate and aggregated apatite nodules are discussed from an energy-barrier point of view. The plate or needle-shaped apatite is favored in single-crystalline form, whereas the granular nodules are favored in the polycrystalline apatite aggregate. The similarity in shape in both single-crystalline needle-shaped apatite and polycrystalline granular apatite over a wide range of sizes is explained by the principle of similitude, in which the growth and shape are determined by the forces acting upon the surface area and the volume.

  10. Electronic and crystallographic structure of apatites

    NASA Astrophysics Data System (ADS)

    Calderín, L.; Stott, M. J.; Rubio, A.

    2003-04-01

    An ab initio study of four different stoichiometric apatites (oxyapatite, hydroxyapatite, fluorapatite, and chlorapatite) is presented. The calculations were performed using density-functional theory with the local-density approximation for exchange and correlation, and a full relaxation of the electronic structure, the atomic arrangement, and the unit cell. Hexagonal unit cells were obtained for all four apatites, and the calculated atomic arrangements are in close agreement with observation in those cases for which the structure is firmly established. A zero-temperature structure is predicted for oxyapatite, and two possible configurations were found for the Cl- ions in chlorapatite. The possibility of the monoclinic structure in hydroxyapatite and chlorapatite was also studied but no indication of greater stability with respect to the hexagonal structure was found. A relationship between the structure of the apatites and that of pure calcium is discussed.

  11. Calibration for Infrared Measurements of Water in Apatite

    NASA Astrophysics Data System (ADS)

    Wang, K. L.; Xu, Z.; Zhang, Y.

    2010-03-01

    We report a study on calibration of infrared (IR) method to determine water concentration in apatite using the elastic recoil detection (ERD) method. The calibration will allow us to constrain water content in lunar and martian apatites using IR spectra.

  12. In-Situ Uranium Stabilization Through Polyphosphate Injection: Pilot-Scale Treatability Test at the 300 Area, Hanford Site

    SciTech Connect

    Vermeul, V.R.; Fruchter, J.S.; Fritz, B.G.; Mackley, R.D.; Wellman, D.M.; Williams, M.D.

    2008-07-01

    This paper describes the pilot-scale treatability test that was conducted to evaluate the efficacy of using a polyphosphate injection approach to treat uranium-contaminated groundwater in situ within the 300 Area aquifer at the Hanford Site in Richland, Washington. Primary test objectives were to assess 1) direct treatment of available uranium contributing to the groundwater plume through precipitation of the uranyl-phosphate mineral autunite, and 2) emplacement of secondary-treatment capacity via precipitation of the calcium-phosphate mineral apatite, which acts as a long-term sorbent for uranium. Based on an injection design analysis that incorporated results from both bench-scale testing and site-specific characterization activities, a three-phase injection approach was selected for field-scale testing. This approach consisted of 1) an initial polyphosphate injection to facilitate direct treatment of aqueous uranium in the pore space, 2) a second phase consisting of a calcium chloride injection to provide an available calcium source for the creation of apatite, and 3) a subsequent polyphosphate injection to supply a phosphate source for the formation of apatite. The total-solution volume injected during this field test was approximately 3.8 million L (1 million gal). Results from this investigation will be used to identify implementation challenges and investigate the technology's ability to meet remedial objectives. In addition, data from this test will provide valuable information for designing a full-scale remedial action for uranium in groundwater beneath the 300 Area of the Hanford Site, and a detailed understanding of the fundamental underpinnings necessary to evaluate the efficacy and potential for utilization of the polyphosphate technology at other sites with varying geochemical and hydrodynamic conditions. (authors)

  13. IN SITU LEAD IMMOBILIZATION BY APATITE

    EPA Science Inventory

    Lead contamination is of environmental concern due to its effect on human health. The purpose of this study was to develop a technology to immobilize Pb in situ in contaminated soils and wastes using apatite. Hydroxyapatite [Ca10(PO4)6(O...

  14. Can Polyphosphate Biochemistry Affect Biological Apatite Saturation?

    NASA Astrophysics Data System (ADS)

    Omelon, S. J.; Matsuura, N.; Gorelikov, I.; Wynnyckyj, C.; Grynpas, M. D.

    2010-12-01

    Phosphorus (P) is an important and limiting element for life. One strategy for storing ortho phosphates (Pi) is polymerization. Polymerized Pi's (polyphosphates: (PO3-)n: polyPs) serve as a Pi bank, as well as a catiion chelator, energy source, & regulator of responses to stresses in the stationary phase of culture growth and development1. PolyP biochemistry has been investigated in yeasts, bacteria & plants2. Bigeochemical cycling of P includes the condensation of Pi into pyro (P2O7-4), & polyPs, & the release of Pi from these compounds by the hydrolytic degradation of Pi from phosphomonoester bonds. Alkaline phosphatase (ALP) is one of the predominate enzymes for regenerating Pi in aquatic systems3, & it cleaves Pi from polyPs. ALP is also the enzyme associated with apatite biomineralization in vertebrates4. PolyP was proposed to be the ALP substrate in bone mineralization5. Where calcium ions are plentiful in many aquatic environments, there is no requirement for aquatic life to generate Ca-stores. However, terrestrial vertebrates benefit from a bioavailable Ca-store such as apatite. The Pi storage strategy of polymerizing PO4-3 into polyPs dovetails well with Ca-banking, as polyPs sequester Ca, forming a neutral calcium polyphosphate (Ca-polyP: (Ca(PO3)2)n) complex. This neutral complex represents a high total [Ca+2] & [PO4-3], without the threat of inadvertent apatite precipitation, as the free [Ca+2] & [PO4-3], and therefore apatite saturation, are zero. Recent identification of polyP in regions of bone resorption & calcifying cartilage5 suggests that vertebrates may use polyP chemistry to bank Ca+2 and PO4-3. In vitro experiments with nanoparticulate Ca-polyP & ALP were undertaken to determine if carbonated apatite could precipitate from 1M Ca-polyP in Pi-free “physiological fluid” (0.1 M NaCl, 2 mM Ca+2, 0.8 mM Mg+2, pH ~8.0 ±0.5, 37 °C), as this is estimated to generate the [Ca+2] & [PO4-3] required to form the apatite content of bone tissue

  15. 100 Area groundwater biodenitrification bench-scale treatability study procedures

    SciTech Connect

    Peyton, B.M.; Martin, K.R.

    1993-05-01

    This document describes the methodologies and procedures for conducting the bench-scale biodenitrification treatability tests at Pacific Northwest Laboratory{sup a} (PNL). Biodenitrification is the biological conversion of nitrate and nitrite to gaseous nitrogen. The tests will use statistically designed batch studies to determine if biodenitrification can reduce residual nitrate concentrations to 45 mg/L, the current maximum contaminant level (MCL). These tests will be carried out in anaerobic flasks with a carbon source added to demonstrate nitrate removal. At the pilot scale, an incremental amount of additional carbon will be required to remove the small amount of oxygen present in the incoming groundwater. These tests will be conducted under the guidance of Westinghouse Hanford Company (WHC) and the 100-HR-3 Groundwater Treatability Test Plan (DOE/RL-92-73) and the Treatability Study Program Plan (DOE/RL-92-48) using groundwater from 100-HR-3. In addition to the procedures, requirements for safety, quality assurance, reporting, and schedule are given. Appendices include analytical procedures, a Quality Assurance Project Plan, a Health and Safety Plan, and Applicable Material Data Safety Sheets. The procedures contained herein are designed specifically for the 100-HR-3 Groundwater Treatability Test Plan, and while the author believes that the methods described herein are scientifically valid, the procedures should not be construed or mistaken to be generally applicable to any other treatability study.

  16. Waste treatability guidance program. User`s guide. Revision 0

    SciTech Connect

    Toth, C.

    1995-12-21

    DOE sites across the country generate and manage radioactive, hazardous, mixed, and sanitary wastes. It is necessary for each site to find the technologies and associated capacities required to manage its waste. One role of DOE HQ Office of Environmental Restoration and Waste Management is to facilitate the integration of the site- specific plans into coherent national plans. DOE has developed a standard methodology for defining and categorizing waste streams into treatability groups based on characteristic parameters that influence waste management technology needs. This Waste Treatability Guidance Program automates the Guidance Document for the categorization of waste information into treatability groups; this application provides a consistent implementation of the methodology across the National TRU Program. This User`s Guide provides instructions on how to use the program, including installations instructions and program operation. This document satisfies the requirements of the Software Quality Assurance Plan.

  17. Sulfur evolution of the 1991 Pinatubo magmas based on apatite

    NASA Astrophysics Data System (ADS)

    Van Hoose, Ashley E.; Streck, Martin J.; Pallister, John S.; Wälle, Markus

    2013-05-01

    Using electron microprobe (EMP) and laser-ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) to collect major and rare-earth elements (REE), respectively, from apatites from the 1991 Mt. Pinatubo juvenile eruption products, we have determined that two statistically distinct populations of apatite exist. One population crystallized from the juvenile basaltic melt (basalt apatites) and the other population crystallized from the main dacitic magma body (silicic apatites). Both populations contain high-S apatites (> 0.7 wt.% SO3). Apatite has previously been shown to be a potential monitor for magmatic sulfur contents via numerous proposed coupled substitutions of P5 + for S6 +. However, simple apatite/melt partitioning cannot account for high-S silicic apatites, which grew from a silicic melt with an apparent maximum S concentration of ~ 80 ppm. Disparate apatite morphology (i.e. skeletal and acicular for basalt apatites and euhedral for silicic apatites) as well as compositional evidence reveal that high-S silicic apatites were not inherited from the juvenile basalt during mingling/mixing prior to eruption. Sulfur gain from neighboring anhydrite phenocrysts can also be ruled-out as a source of high sulfur. EMP sulfur mapping of silicic apatites shows highly irregular patterns of sulfur enrichment that do not correspond with adjacent anhydrite and can be found within apatites hosted by other minerals (e.g. hornblende and Fe-Ti oxides). With these data in mind, we propose high-S silicic apatites from Pinatubo and other sulfur-rich systems achieved elevated sulfur concentrations during high sulfur fluxing events that originated from underplated basalt during degassing of a SO2-rich fluid phase. That basalts were indeed sulfur rich and oxidized is here indicated by high S contents of apatites growing in basalt. The predominant location of S-rich areas of silicic apatite is crystal interiors of apatite inclusions in other mineral phases, while large apatite

  18. Treatability Test Plan for an In Situ Biostimulation Reducing Barrier

    SciTech Connect

    Truex, Michael J.; Vermeul, Vince R.; Long, Philip E.; Brockman, Fred J.; Oostrom, Mart; Hubbard, Susan; Borden, Robert C.; Fruchter, Jonathan S.

    2007-10-26

    This treatability test plan supports a new, integrated strategy to accelerate cleanup of chromium in the 100 Areas at the Hanford Site. This plan includes performing a field-scale treatability test for bioreduction of chromate, nitrate, and dissolved oxygen. In addition to remediating a portion of the plume and demonstrating reduction of electron acceptors in the plume, the data from this test will be valuable for designing a full-scale bioremediation system to apply at this and other chromium plumes at the Hanford Site.

  19. The determination of uranium (IV) in apatite

    USGS Publications Warehouse

    Clarke, Roy S.; Altschuler, Zalman S.

    1956-01-01

    Geologic and mineralogic evidence indicate that the uranium present in apatite may proxy for calcium in the mineral structure as U(IV). An experimental investigation was conducted and chemical evidence was obtained that establishes the presence of U(IV) in apatite. The following analytical procedure was developed for the determination of U(IV). Carbonate-fluorapatite is dissolved in cold 1.5M orthophosphoric acid and fluorapatite is dissolved in cold 1.2M hydrochloric acid containing 1.5 g of hydroxylamine hydrochloride per 100 ml. Uranium (IV) is precipitated by cupferron using titanium as a carrier. The uranium in the precipitate is separated by use of the ethyl acetate extraction procedure and determined fluorimetrically. The validity and the limitations of the method have been established by spike experiments.

  20. Rare earth element diffusion in apatite

    NASA Astrophysics Data System (ADS)

    Cherniak, D. J.

    2000-11-01

    Diffusion of rare earth elements (REEs) in natural and synthetic fluorapatite has been characterized under anhydrous conditions. Three types of experiments were run. In the first set of experiments, Sm was introduced into the apatite by means of ion implantation, with diffusivities extracted through measurement of the "relaxation" of the implanted profile after diffusion anneals. The second group consisted of "in diffusion" experiments, in which apatite was immersed in reservoirs of synthetic REE apatite analogs of various compositions. The final set of experiments was "out-diffusion" experiments run on synthetic Nd-doped apatite immersed in a reservoir of synthetic (undoped) fluorapatite. REE depth profiles in all cases were measured with Rutherford Backscattering Spectrometry. Diffusion rates for the REE vary significantly among these sets of experiments. For the ion-implantation experiments, the following Arrhenius relation was obtained for Sm, over the temperature range 750°C to 1100°C: D imp=6.3×10-7exp(-298±17 kJ/mol/RT) m2/s Diffusion of a series of REE, from light to heavy, was investigated in the "in-diffusion" experiments. Over the temperature range 800°C to 1250°C, the following Arrhenius relations are obtained for La, Nd, Dy, and Yb, for in-diffusion experiments using REE silicate oxyapatite sources: D La=2.6×10-7exp(-324±9 kJ/mol/RT) m2/sD Nd=2.4×10-6exp(-348±13 kJ/mol/RT) m2/sD Dy=9.7×10-7exp(-340±11 kJ/mol/RT) m2/sD Yb=1.3×10-8exp(-292±23 kJ/mol/RT) m2/s Diffusivities of the REE in these "in-diffusion" experiments are all quite similar, suggesting little difference in diffusion rates in apatite with increasing ionic radii of the REEs. The "out-diffusion" experiments on the Nd-doped synthetic apatite, over the temperature range 950°C to 1400°C, yield the Arrhenius law: D out=9.3×10-6exp(-392±31 kJ/mol/RT) m2/s The differences in REE diffusion among these three sets of experiments (i.e., ion implantation, in-diffusion, and out

  1. Lunar apatite with terrestrial volatile abundances.

    PubMed

    Boyce, Jeremy W; Liu, Yang; Rossman, George R; Guan, Yunbin; Eiler, John M; Stolper, Edward M; Taylor, Lawrence A

    2010-07-22

    The Moon is thought to be depleted relative to the Earth in volatile elements such as H, Cl and the alkalis. Nevertheless, evidence for lunar explosive volcanism has been used to infer that some lunar magmas exsolved a CO-rich and CO(2)-rich vapour phase before or during eruption. Although there is also evidence for other volatile species on glass spherules, until recently there had been no unambiguous reports of indigenous H in lunar rocks. Here we report quantitative ion microprobe measurements of late-stage apatite from lunar basalt 14053 that document concentrations of H, Cl and S that are indistinguishable from apatites in common terrestrial igneous rocks. These volatile contents could reflect post-magmatic metamorphic volatile addition or growth from a late-stage, interstitial, sulphide-saturated melt that contained approximately 1,600 parts per million H(2)O and approximately 3,500 parts per million Cl. Both metamorphic and igneous models of apatite formation suggest a volatile inventory for at least some lunar materials that is similar to comparable terrestrial materials. One possible implication is that portions of the lunar mantle or crust are more volatile-rich than previously thought. PMID:20651686

  2. Lunar apatite with terrestrial volatile abundances.

    PubMed

    Boyce, Jeremy W; Liu, Yang; Rossman, George R; Guan, Yunbin; Eiler, John M; Stolper, Edward M; Taylor, Lawrence A

    2010-07-22

    The Moon is thought to be depleted relative to the Earth in volatile elements such as H, Cl and the alkalis. Nevertheless, evidence for lunar explosive volcanism has been used to infer that some lunar magmas exsolved a CO-rich and CO(2)-rich vapour phase before or during eruption. Although there is also evidence for other volatile species on glass spherules, until recently there had been no unambiguous reports of indigenous H in lunar rocks. Here we report quantitative ion microprobe measurements of late-stage apatite from lunar basalt 14053 that document concentrations of H, Cl and S that are indistinguishable from apatites in common terrestrial igneous rocks. These volatile contents could reflect post-magmatic metamorphic volatile addition or growth from a late-stage, interstitial, sulphide-saturated melt that contained approximately 1,600 parts per million H(2)O and approximately 3,500 parts per million Cl. Both metamorphic and igneous models of apatite formation suggest a volatile inventory for at least some lunar materials that is similar to comparable terrestrial materials. One possible implication is that portions of the lunar mantle or crust are more volatile-rich than previously thought.

  3. LOSS OF ORGANIC CHEMICALS IN SOIL: PURE COMPOUND TREATABILITY STUDIES

    EPA Science Inventory

    Comprehensive screening data on the treatability of 32 organic chemicals in soil were developed. Of the evaluated chemicals, 22 were phenolic compounds. Aerobic batch laboratory microcosm experiments were conducted using two soils: an acidic clay soil with <1% organic matter and ...

  4. TREATABILITY POTENTIAL FOR EPA LISTED HAZARDOUS WASTES IN SOIL

    EPA Science Inventory

    This study developed comprehensive screening data on the treatability in soil of: (a) specific listed hazardous organic chemicals, and (b) waste sludge from explosives production (K044) and related chemicals. Laboratory experiments were conducted using two soil types, an acidic s...

  5. 100 Area excavation treatability test plan. Revision 1

    SciTech Connect

    Not Available

    1993-08-01

    This test plan documents the requirements for a treatability study on field radionuclide analysis and dust control techniques. These systems will be used during remedial actions involving excavation. The data from this treatability study will be used to support the feasibility study (FS) process. Excavation is one of the high-priority, near-term, treatability study needs identified in the program plan (DOE-RL 1992f). Excavation of contaminated soils and buried solid wastes is included in several of the alternatives identified in the 100 Area FS. Although a common activity, excavation has only been used occasionally at the Hanford Site for waste removal applications. The most recent applications are excavation of the 618-9 burial ground and partial remediation of the 316-5 process trenches (DOE-RL 1992a, 1992b). Both projects included excavation of soil and dust control (using water sprays). Excavation is a well-developed technology and equipment is readily available; however, certain aspects of the excavation process require testing before use in full-scale operations. These include the following: Measurement and control of excavation-generated dust and airborne contamination; verification of field analytical system capabilities; demonstration of soil removal techniques specific to the 100 Area waste site types and configurations. The execution of this treatability test may produce up to 500 yd{sub 3} of contaminated soil, which will be used for future treatability tests. These tests may include soil washing with vitrification of the soil washing residuals. Other tests will be conducted if soil washing is not a viable alternative.

  6. The chemistry of five accessory rock-forming apatites

    USGS Publications Warehouse

    Lee, Donald E.; Rose, Harry J.; Brandt, Elaine L. Munson; Van Loenen, Richard E.

    1973-01-01

    Chemical and physical data are given for five samples of rock-forming apatite from diverse geologic environments in Nevada and Colorado.  Four of these apatites contain rare-earth assemblages in which the cerium group is well represented but the yttrium group predominates.  The fifth apatite contains a highly fractionated assemblage of the lighter (cerium group) rare earths similar to the assemblage typical of alkulic rocks.

  7. Transient precursor strategy or very small biological apatite crystals?

    PubMed

    Grynpas, Marc D; Omelon, Sidney

    2007-08-01

    The mechanisms of skeletal mineralization have been studied and debated for decades. Recent Raman spectroscopic identification of octacalcium phosphate-like phosphate ions and possibly amorphous calcium phosphate ions in nascent bone mineral were claimed to support a transient precursor strategy for bone apatite formation. However, this data does not refute the theory that the newest, detectable bone mineral is very small, poorly crystalline biological apatite, because non-apatitic phosphate species have previously been identified in biological apatite and detected on the surfaces of nano-sized hydroxyapatite crystals.

  8. Distribution of halogens during fluid-mediated apatite replacement

    NASA Astrophysics Data System (ADS)

    Kusebauch, Christof; John, Timm; Whitehouse, Martin J.

    2016-04-01

    Apatite (Ca5(PO4)3(F,Cl,OH)) is one the most abundant halogen containing minerals in the crust. It is present in many different rock types and stable up to P-T conditions of the mantle. Although probably not relevant for the halogen budget of the mantle, apatite is potentially a carrier phase of halogens into the mantle via subduction processes and therefore important for the global halogen cycle. Different partitioning behavior of the halogens between apatite and melt/fluids causes fractionation of these elements. In hydrothermal environments apatite reacts via a coupled dissolution-reprecipitation process that leads to apatite halogen compositions which are in (local) equilibrium with the hydrothermal fluid. This behavior enables apatite to be used as fluid probe and as a tool for tracking fluid evolution during fluid-rock interaction. Here, we present a combined experimental and field related study focused on replacement of apatite under hydrothermal conditions, to investigate the partitioning of halogens between apatite and fluids. Experiments were conducted in a cold seal pressure apparatus at 0.2 GPa and temperatures ranging from 400-700°C using halogen bearing solutions of different composition (KOH, NaF, NaCl, NaBr, NaI) to promote the replacement of Cl-apatite. The halogen composition of reacted apatite was analyzed by electron microprobe (EMPA) and secondary ion mass spectrometry (SIMS). The data was used to calculate partition coefficients of halogens between fluid and apatite. Our new partitioning data show that fluorine is the most compatible halogen followed by chlorine, bromine and iodine. Comparison between partition coefficients of the apatite-fluid system and coefficients derived in the apatite-melt system reveals values for F that are one to two orders of magnitude higher. In contrast, Cl and Br show a similar partition behavior in fluid and melt systems. Consequently, apatite that formed by fluid-rock interaction will fractionate F from Cl more

  9. Hanford Site Annual Treatability Studies Report, Calendar Year 2002

    SciTech Connect

    Grohs, Eugene L.

    2003-02-28

    This report provides information required to be reported annually by the Washington Administrative Code (WAC) 173-303-071 (3)(r)(ii)(F) and (3)(s)(ix) on the treatability studies conducted on the Hanford Site in 2002. These studies were conducted as required by WAC 173-303-071, “Excluded Categories of Waste,” sections (3)(r) and (s). Unless otherwise noted, the waste samples were provided by and the treatability studies were performed for the U.S. Department of Energy, Richland Operations Office, P.O. Box 550, Richland, Washington 99352. The U.S. Environmental Protection Agency identification number for these studies is WA7890008967.

  10. The treatability requirement in psychopathy: a new ethical dilemma?

    PubMed

    Millard, D W

    1984-06-01

    The Mental Health Act 1983 for England and Wales includes a treatability requirement, first introduced in the Mental Health (Amendment) Act 1982, that outlaws compulsory admission of a patient for treatment of "psychopathic disorder or mental impairment" unless "such treatment is likely to alleviate or prevent a deterioration of his condition." The author contends that this requirement raises a new ethical dilemma for psychiatry because of the uncertainty associated with predicting the outcome of psychopathic disorder.

  11. Time and the crystallization of apatite in seawater

    USGS Publications Warehouse

    Gulbrandsen, R.A.; Roberson, C.E.; Neil, S.T.

    1984-01-01

    Carbonate fluorapatite has been synthesized in seawater in an experiment of nearly 10-years duration. The addition of phosphate to seawater whose fluoride concentration had been increased to 7.6 mg/l brought about an initial amorphous phosphate precipitate. After 20 months, a crystalline magnesium phosphate phase developed within the amorphous phosphate. Crystallization of apatite, which occurred during the last 3 years of the experiment, was accompanied by dissolution of the crystalline magnesium phosphate phase. The MgO content of the apatite (1.9 percent) is high in comparison to Tertiary and older apatite but similar to some young apatite; the CO2 content (3.6 percent) is medium, and the fluorine content (2.2 percent) is low but again similar to some young apatite. The hydroxyl ion (OH-) likely fills the need for additional fluorine-position atoms. The mole ratio of Ca plus substituent elements to P plus substituent elements (1.50) is low in comparison to the expected ratio of 1.67. The substitution of the hydronium ion (H3O+) for Ca may account for this difference. The synthesis of apatite in seawater demonstrates that the factor of time overcomes the well known inhibiting effect of magnesium upon the crystallization of apatite. It also implies that given an adequate supply of phosphate, apatite can form in most ocean environments and likely plays a major pan in the control of the phosphate content of seawater. ?? 1984.

  12. Psychiatric manifestations of treatable hereditary metabolic disorders in adults

    PubMed Central

    2014-01-01

    Detecting psychiatric disorders of secondary origin is a crucial concern for the psychiatrist. But how can this reliably be done among a large number of conditions, most of which have a very low prevalence? Metabolic screening undertaken in a population of subjects with psychosis demonstrated the presence of treatable metabolic disorders in a significant number of cases. The nature of the symptoms that should alert the clinician is also a fundamental issue and is not limited to psychosis. Hereditary metabolic disorders (HMD) are a rare but important cause of psychiatric disorders in adolescents and adults, the signs of which may remain isolated for years before other more specific organic signs appear. HMDs that present purely with psychiatric symptoms are very difficult to diagnose due to low awareness of these rare diseases among psychiatrists. However, it is important to identify HMDs in order to refer patients to specialist centres for appropriate management, disease-specific treatment and possible prevention of irreversible physical and neurological complications. Genetic counselling can also be provided. This review focuses on three HMD categories: acute, treatable HMDs (urea cycle abnormalities, remethylation disorders, acute intermittent porphyria); chronic, treatable HMDs (Wilson’s disease, Niemann-Pick disease type C, homocystinuria due to cystathionine beta-synthase deficiency, cerebrotendinous xanthomatosis); and chronic HMDs that are difficult to treat (lysosomal storage diseases, X-linked adrenoleukodystrophy, creatine deficiency syndrome). We also propose an algorithm for the diagnosis of HMDs in patients with psychiatric symptoms. PMID:25478001

  13. Preparation and Evaluation of Two Apatites with Spherical Nanocrystal Morphology.

    PubMed

    Zhang, Yali; Li, Qihong; Li, Xiaojie; Li, Yong; Wang, Chunhui; Zhao, Yantao; Song, Yingliang; Liu, Yanpu

    2016-03-01

    Spherical nanocrystal of apatite has been proved to be beneficial for osteoblast growth. Two apatites with spherical nanocrystal morphology were prepared in this study by chemical wet method and further sintering process. SEM exhibited that both apatites had spherical nanocrystal morphology. The crystal morphology and size was approaching to each other. XRD showed the apatites separately were hydroxyapatite and tricalcium phosphate phases. The cellular biocompatibility was evaluated by osteoblasts for these two spherical nanocrstal apatites. The MTT result indicated a higher cell proliferation rate for spherical tricalcium phosphate group. The ALP activity assay also strongly favored the tricalcium phosphate group. RT-PCR results indicated that Collagen I had a higher transcription level on the spherical tricalcium phosphate group. SEM results showed robust cell growth on the materials. It was concluded that the spherical nanophase tricalcium phosphate was superior to the cellular biocompatibility of spherical nanophase hydroxyapatite and the results were helpful in the manufacture of more suitable tissue engineering scaffolds.

  14. Strongly bound citrate stabilizes the apatite nanocrystals in bone.

    PubMed

    Hu, Y-Y; Rawal, A; Schmidt-Rohr, K

    2010-12-28

    Nanocrystals of apatitic calcium phosphate impart the organic-inorganic nanocomposite in bone with favorable mechanical properties. So far, the factors preventing crystal growth beyond the favorable thickness of ca. 3 nm have not been identified. Here we show that the apatite surfaces are studded with strongly bound citrate molecules, whose signals have been identified unambiguously by multinuclear magnetic resonance (NMR) analysis. NMR reveals that bound citrate accounts for 5.5 wt% of the organic matter in bone and covers apatite at a density of about 1 molecule per (2 nm)(2), with its three carboxylate groups at distances of 0.3 to 0.45 nm from the apatite surface. Bound citrate is highly conserved, being found in fish, avian, and mammalian bone, which indicates its critical role in interfering with crystal thickening and stabilizing the apatite nanocrystals in bone. PMID:21127269

  15. Production of spherical apatite powders—the first step for optimized thermal-sprayed apatite coatings

    NASA Astrophysics Data System (ADS)

    Lugscheider, E.; Knepper, M.; Gross, K. A.

    1992-09-01

    Regardless of the thermal spraying system, a coating can only be as good as the quality of the input powders. Powder quality in turn is dependent on the manufacturing process and conditions. Thus, it is possible to alter characteristics such as morphology, porosity, phase composition, and the mechanical strength of the individual particles. This article looks at powder agglomerations using the spray drying technique. Two different spray drying configurations were used to produce spherical apatite powders. Apatite powders could be produced with variable densities. Rotary-atomized powders possessed internal porosity as well as open porosity. More applicable for thermal spraying are the nozzle-atomized powders, which are more dense. The particle size range produced is dependent on the many parameters in the spray drying process. Hydroxyapatite is more sensitive than fluorapatite to alterations in process conditions. The powders produced were clean, free of other phases, and possessed good flowability for thermal spraying purposes.

  16. The treatable intellectual disability APP www.treatable-id.org: A digital tool to enhance diagnosis & care for rare diseases

    PubMed Central

    2012-01-01

    Background Intellectual disability (ID) is a devastating and frequent condition, affecting 2-3% of the population worldwide. Early recognition of treatable underlying conditions drastically improves health outcomes and decreases burdens to patients, families and society. Our systematic literature review identified 81 such inborn errors of metabolism, which present with ID as a prominent feature and are amenable to causal therapy. The WebAPP translates this knowledge of rare diseases into a diagnostic tool and information portal. Methods & results Freely available as a WebAPP via http://www.treatable-id.org and end 2012 via the APP store, this diagnostic tool is designed for all specialists evaluating children with global delay / ID and laboratory scientists. Information on the 81 diseases is presented in different ways with search functions: 15 biochemical categories, neurologic and non-neurologic signs & symptoms, diagnostic investigations (metabolic screening tests in blood and urine identify 65% of all IEM), therapies & effects on primary (IQ/developmental quotient) and secondary outcomes, and available evidence For each rare condition a ‘disease page’ serves as an information portal with online access to specific genetics, biochemistry, phenotype, diagnostic tests and therapeutic options. As new knowledge and evidence is gained from expert input and PubMed searches this tool will be continually updated. The WebAPP is an integral part of a protocol prioritizing treatability in the work-up of every child with global delay / ID. A 3-year funded study will enable an evaluation of its effectiveness. Conclusions For rare diseases, a field for which financial and scientific resources are particularly scarce, knowledge translation challenges are abundant. With this WebAPP technology is capitalized to raise awareness for rare treatable diseases and their common presenting clinical feature of ID, with the potential to improve health outcomes. This innovative digital

  17. Sulfur evolution of the 1991 Pinatubo magmas based on apatite

    NASA Astrophysics Data System (ADS)

    Van Hoose, A. E.; Streck, M. J.; Pallister, J. S.

    2011-12-01

    The 1991 eruptions of Mt. Pinatubo, Philippines, were triggered by basaltic recharge into the 50 km3 dacitic magma reservoir, and released 20 million tonnes of SO2 into the stratosphere. Three primary juvenile products erupted: dacite, hybrid andesite, and basaltic inclusions. Sulfur bearing apatites occur in all three juvenile components, yet observed S content is variable. Basaltic magma includes only high-S (>0.7 wt.% SO3) apatites, while dacitic and hybrid andesitic magmas carry low- (<0.3 wt.% SO3), med.- (0.3-0.7 wt.% SO3), and high-S apatites. Pre-eruption conditions (~780°C, 220 MPa, NNO+1.7, and 77 ppm S) (Rutherford & Devine, 1996; Scaillet & Evans, 1999) and a partition coefficient of 13 (Baker & Rutherford, 1996) could yield only low-S apatite containing up to 0.25 wt.% SO3, which is consistent with the SO3 concentrations found in large (≤200 μm) apatite microphenocrysts in glass. Med.-S apatite would still be consistent with pre-eruption conditions if melt sulfur was once at the solubility maximum of ~350 ppm (cf., Clemente et al., 2004). However, concentrations of SO3 in nearly 30% of dacite-hosted apatites analyzed exceeded 0.7 wt.%, which is much higher than can be achieved through apatite/melt equilibrium partitioning. Such high-S apatite of dacite occur only as inclusions in other phenocrysts (anhydrite, plagioclase, hornblende, and Fe-Ti oxide) and were likely generated during conditions leading to accumulation of the pre-eruptive, separate S gas phase responsible for the "excess sulfur" at Pinatubo. Other explanations, such as inheritance from mafic magmas or diffusional exchange with closely associated anhydrite, can be ruled out. Evidence against the former is found in distinct crystal populations based on major (e.g. Mg, Cl) and trace elements (e.g. total REE, Eu/Eu*, Sr), separating "silicic" apatites (i.e. those hosted in dacite or andesite, irrespective of S content) from basalt apatites. S element maps of apatites hosted by anhydrite

  18. UV photofunctionalization promotes nano-biomimetic apatite deposition on titanium

    PubMed Central

    Saita, Makiko; Ikeda, Takayuki; Yamada, Masahiro; Kimoto, Katsuhiko; Lee, Masaichi Chang-Il; Ogawa, Takahiro

    2016-01-01

    Background Although biomimetic apatite coating is a promising way to provide titanium with osteoconductivity, the efficiency and quality of deposition is often poor. Most titanium implants have microscale surface morphology, and an addition of nanoscale features while preserving the micromorphology may provide further biological benefit. Here, we examined the effect of ultraviolet (UV) light treatment of titanium, or photofunctionalization, on the efficacy of biomimetic apatite deposition on titanium and its biological capability. Methods and results Micro-roughed titanium disks were prepared by acid-etching with sulfuric acid. Micro-roughened disks with or without photofunctionalization (20-minute exposure to UV light) were immersed in simulated body fluid (SBF) for 1 or 5 days. Photofunctionalized titanium disks were superhydrophilic and did not form surface air bubbles when immersed in SBF, whereas non-photofunctionalized disks were hydrophobic and largely covered with air bubbles during immersion. An apatite-related signal was observed by X-ray diffraction on photofunctionalized titanium after 1 day of SBF immersion, which was equivalent to the one observed after 5 days of immersion of control titanium. Scanning electron microscopy revealed nodular apatite deposition in the valleys and at the inclines of micro-roughened structures without affecting the existing micro-configuration. Micro-roughened titanium and apatite-deposited titanium surfaces had similar roughness values. The attachment, spreading, settling, proliferation, and alkaline phosphate activity of bone marrow-derived osteoblasts were promoted on apatite-coated titanium with photofunctionalization. Conclusion UV-photofunctionalization of titanium enabled faster deposition of nanoscale biomimetic apatite, resulting in the improved biological capability compared to the similarly prepared apatite-deposited titanium without photofunctionalization. Photofunctionalization-assisted biomimetic apatite

  19. Immobilization of uranium in contaminated soil by natural apatite addition

    SciTech Connect

    Mrdakovic Popic, Jelena; Stojanovic, Mirjana; Milosevic, Sinisa; Iles, Deana; Zildzovic, Snezana

    2007-07-01

    Available in abstract form only. Full text of publication follows: The goal of this study was to evaluate the effectiveness of Serbian natural mineral apatite as soil additive for reducing the migration of uranium from contaminated sediments. In laboratory study we investigated the sorption properties of domestic apatite upon different experimental conditions, such as pH, adsorbent mass, reaction period, concentration of P{sub 2}O{sub 5} in apatite, solid/liquid ratio. In second part of study, we did the quantification of uranium in soil samples, taken from uranium mine site 'Kalna', by sequential extraction method. The same procedure was, also, used for uranium determination in contaminated soil samples after apatite addition, in order to determine the changes in U distribution in soil fraction. The obtained results showed the significant level of immobilization (96.7%) upon certain conditions. Increase of %P{sub 2}O{sub 5} in apatite and process of mechano-chemical activation led to increase of immobilization capacity from 17.50% till 91.64%. The best results for uranium binding were obtained at pH 5.5 and reaction period 60 days (98.04%) The sequential extraction showed the presence of uranium (48.2%) in potentially available soil fractions, but with the apatite addition uranium content in these fractions decreased (30.64%), what is considering environmental aspect significant fact. In situ immobilization of radionuclide using inexpensive sequestering agents, such as apatite, is very adequate for big contaminated areas of soil with low level of contamination. This investigation study on natural apatite from deposit 'Lisina' Serbia was the first one of this type in our country. Key words: apatite, uranium, immobilization, soil, contamination. (authors)

  20. [Treatable Dementia due to Vitamin B12 and Folate Deficiency].

    PubMed

    Yoshizawa, Toshihiro

    2016-04-01

    Vitamin deficiency is one of the major causes of treatable dementia. Specifically, patients suffering from dementia frequentry display low serum levels of vitamin B(12). There is a close metabolic interaction between folate and vitamin B(12). Folate deficiency causes various neuropsychiatric symptoms, which resemble those observed in vitamin B(12) deficiency. This review summarizes, the basic pathophysiology of vitamin B(12) and folate deficiency, its clinical diagnosis, associated neuropsychiatric symptoms such as subacute combined degeneration and dementia, and epidemiological studies of cognitive decline and brain atrophy.

  1. Apatite Biomineralization: Model Studies of Composition and Kinetics

    NASA Astrophysics Data System (ADS)

    Tecklenburg, M. M. J.; Urbanawiz, S. A.; Derry, A. W.; Ling, M. L.; Zhou, D.; Pavan, B.

    2014-06-01

    Biomineralization of bone and teeth is modeled via studies of apatite crystallization to assess the effects of constituent ions and centrifugal force on kinetics of the amorphous to crystalline phase transition.

  2. Electron Microprobe Analysis Techniques for Accurate Measurements of Apatite

    NASA Astrophysics Data System (ADS)

    Goldoff, B. A.; Webster, J. D.; Harlov, D. E.

    2010-12-01

    Apatite [Ca5(PO4)3(F, Cl, OH)] is a ubiquitous accessory mineral in igneous, metamorphic, and sedimentary rocks. The mineral contains halogens and hydroxyl ions, which can provide important constraints on fugacities of volatile components in fluids and other phases in igneous and metamorphic environments in which apatite has equilibrated. Accurate measurements of these components in apatite are therefore necessary. Analyzing apatite by electron microprobe (EMPA), which is a commonly used geochemical analytical technique, has often been found to be problematic and previous studies have identified sources of error. For example, Stormer et al. (1993) demonstrated that the orientation of an apatite grain relative to the incident electron beam could significantly affect the concentration results. In this study, a variety of alternative EMPA operating conditions for apatite analysis were investigated: a range of electron beam settings, count times, crystal grain orientations, and calibration standards were tested. Twenty synthetic anhydrous apatite samples that span the fluorapatite-chlorapatite solid solution series, and whose halogen concentrations were determined by wet chemistry, were analyzed. Accurate measurements of these samples were obtained with many EMPA techniques. One effective method includes setting a static electron beam to 10-15nA, 15kV, and 10 microns in diameter. Additionally, the apatite sample is oriented with the crystal’s c-axis parallel to the slide surface and the count times are moderate. Importantly, the F and Cl EMPA concentrations are in extremely good agreement with the wet-chemical data. We also present EMPA operating conditions and techniques that are problematic and should be avoided. J.C. Stormer, Jr. et al., Am. Mineral. 78 (1993) 641-648.

  3. Hanford 100-D Area Biostimulation Treatability Test Results

    SciTech Connect

    Truex, Michael J.; Vermeul, Vincent R.; Fritz, Brad G.; Mackley, Rob D.; Mendoza, Donaldo P.; Elmore, Rebecca P.; Mitroshkov, Alexandre V.; Sklarew, Deborah S.; Johnson, Christian D.; Oostrom, Martinus; Newcomer, Darrell R.; Brockman, Fred J.; Bilskis, Christina L.; Hubbard, Susan S.; Peterson, John E.; Williams, Kenneth H.; Gasperikova, E.; Ajo-Franklin, J.

    2009-09-30

    Pacific Northwest National Laboratory conducted a treatability test designed to demonstrate that in situ biostimulation can be applied to help meet cleanup goals in the Hanford Site 100-D Area. In situ biostimulation has been extensively researched and applied for aquifer remediation over the last 20 years for various contaminants. In situ biostimulation, in the context of this project, is the process of amending an aquifer with a substrate that induces growth and/or activity of indigenous bacteria for the purpose of inducing a desired reaction. For application at the 100-D Area, the purpose of biostimulation is to induce reduction of chromate, nitrate, and oxygen to remove these compounds from the groundwater. The in situ biostimulation technology is intended to provide supplemental treatment upgradient of the In Situ Redox Manipulation (ISRM) barrier previously installed in the Hanford 100-D Area and thereby increase the longevity of the ISRM barrier. Substrates for the treatability test were selected to provide information about two general approaches for establishing and maintaining an in situ permeable reactive barrier based on biological reactions, i.e., a biobarrier. These approaches included 1) use of a soluble (miscible) substrate that is relatively easy to distribute over a large areal extent, is inexpensive, and is expected to have moderate longevity; and 2) use of an immiscible substrate that can be distributed over a reasonable areal extent at a moderate cost and is expected to have increased longevity.

  4. Process and equipment development for hot isostatic pressing treatability study

    SciTech Connect

    Bateman, Ken; Wahlquist, Dennis; Malewitz, Tim

    2015-03-01

    Battelle Energy Alliance (BEA), LLC, has developed processes and equipment for a pilot-scale hot isostatic pressing (HIP) treatability study to stabilize and volume reduce radioactive calcine stored at Idaho National Laboratory (INL). In 2009, the U. S. Department of Energy signed a Record of Decision with the state of Idaho selecting HIP technology as the method to treat 5,800 yd^3 (4,400 m^3) of granular zirconia and alumina calcine produced between 1953 and 1992 as a waste byproduct of spent nuclear fuel reprocessing. Since the 1990s, a variety of radioactive and hazardous waste forms have been remotely treated using HIP within INL hot cells. To execute the remote process at INL, waste is loaded into a stainless-steel or aluminum can, which is evacuated, sealed, and placed into a HIP furnace. The HIP simultaneously heats and pressurizes the waste, reducing its volume and increasing its durability. Two 1 gal cans of calcine waste currently stored in a shielded cask were identified as candidate materials for a treatability study involving the HIP process. Equipment and materials for cask-handling and calcine transfer into INL hot cells, as well as remotely operated equipment for waste can opening, particle sizing, material blending, and HIP can loading have been designed and successfully tested. These results demonstrate BEA’s readiness for treatment of INL calcine.

  5. Hydrated lime for metals immobilization and explosives transformation: Treatability study.

    PubMed

    Martin, W Andy; Larson, S L; Nestler, C C; Fabian, G; O'Connor, G; Felt, D R

    2012-05-15

    Fragmentation grenades contain Composition B (RDX and TNT) within a steel shell casing. There is the potential for off-site migration of high explosives and metals from hand grenade training ranges by transport in surface water and subsurface transport in leachate. This treatability study used bench-scale columns and mesocosm-scale laboratory lysimeters to investigate the potential of hydrated lime as a soil amendment for in situ remediation of explosives and metals stabilization in hand grenade range soils. Compared to the unamended soil there was a 26-92% reduction of RDX in the leachate and runoff water from the lime treated soils and a 66-83% reduction of zinc in the leachate and runoff water samples; where the hand grenade range metals of concern were zinc, iron, and manganese. The amended soil was maintained at the target pH of greater than 10.5 for optimum explosives decomposition. The treatability study indicated a high potential of success for scale-up to an in situ field study. PMID:22445717

  6. Insight into Biological Apatite: Physiochemical Properties and Preparation Approaches

    PubMed Central

    Liu, Quan; Matinlinna, Jukka Pekka; Chen, Zhuofan; Pan, Haobo

    2013-01-01

    Biological apatite is an inorganic calcium phosphate salt in apatite form and nano size with a biological derivation. It is also the main inorganic component of biological hard tissues such as bones and teeth of vertebrates. Consequently, biological apatite has a wide application in dentistry and orthopedics by using as dental fillers and bone substitutes for bone reconstruction and regeneration. Given this, it is of great significance to obtain a comprehensive understanding of its physiochemical and biological properties. However, upon the previous studies, inconsistent and inadequate data of such basic properties as the morphology, crystal size, chemical compositions, and solubility of biological apatite were reported. This may be ascribed to the differences in the source of raw materials that biological apatite are made from, as well as the effect of the preparation approaches. Hence, this paper is to provide some insights rather than a thorough review of the physiochemical properties as well as the advantages and drawbacks of various preparation methods of biological apatite. PMID:24078928

  7. Apatite mineralization in elasmobranch skeletons via a polyphosphate intermediate

    NASA Astrophysics Data System (ADS)

    Omelon, Sidney; Lacroix, Nicolas; Lildhar, Levannia; Variola, Fabio; Dean, Mason

    2014-05-01

    All vertebrate skeletons are stiffened with apatite, a calcium phosphate mineral. Control of apatite mineralization is essential to the growth and repair of the biology of these skeletons, ensuring that apatite is deposited in the correct tissue location at the desired time. The mechanism of this biochemical control remains debated, but must involve increasing the localized apatite saturation state. It was theorized in 1923 that alkaline phosphatase (ALP) activity provides this control mechanism by increasing the inorganic phosphate (Pi) concentration via dephosphorylation of phosphorylated molecules. The ALP substrate for biological apatite is not known. We propose that polyphosphates (polyPs) produced by mitochondria may be the substrate for biological apatite formation by ALP activity. PolyPs (PO3-)n, also known as condensed phosphates, represent a concentrated, bioavailable Pi-storage strategy. Mitochondria import Pi and synthesize phosphate polymers through an unknown biochemical mechanism. When chelated with calcium and/or other cations, the effective P-concentration of these neutrally charged, amorphous, polyP species can be very high (~ 0.5 M), without inducing phosphate mineral crystallization. This P-concentration in the low Pi-concentration biological environment offers a method of concentrating P well above an apatite supersaturation required for nucleation. Bone is the most studied mineralized skeletal tissue. However, locating and analyzing active mineralizing areas is challenging. We studied calcified cartilage skeletons of elasmobranch fishes (sharks, stingrays and relatives) to analyse the phosphate chemistry in this continually mineralizing skeleton. Although the majority of the elasmobranch skeleton is unmineralized cartilage, it is wrapped in an outer layer of mineralized tissue comprised of small tiles called tesserae. These calcified tesserae continually grow through the formation of new mineral on their borders. Co-localization of ALP and

  8. Apatite at Olympic Dam, South Australia: A petrogenetic tool

    NASA Astrophysics Data System (ADS)

    Krneta, Sasha; Ciobanu, Cristiana L.; Cook, Nigel J.; Ehrig, Kathy; Kontonikas-Charos, Alkis

    2016-10-01

    The > 10,000 million tonne Olympic Dam Cu-Au-U-Ag deposit, (eastern Gawler Craton, South Australia) is one of the largest orebodies in the World. The deposit is hosted within the Olympic Dam Breccia Complex, placed at the centre of, and resulting from multiple brecciation and Fe-metasomatism of the Roxby Downs Granite (RDG). The latter is part of a larger batholith emplaced at ~ 1.6 Ga. Apatite petrography and chemistry were studied in non-mineralised RDG and coeval granitoids and dolerites, as well as in mineralised RDG from deep (> 2 km) and distal (2.7 km to NE) locations. In both latter cases, although the mineralisation corresponds to the same, early chalcopyrite-pyrite-magnetite ± hematite stage identified in the outer and deeper zones of the deposit itself, the character of granite alteration differs: sericite-chlorite alteration with all feldspar replaced in the deep location; and red-stained K-feldspar on top of prevailing albitization in the distal location. Close-to end-member fluorapatite is a key accessory mineral in all igneous rocks and a common product of early hydrothermal alteration within mineralised granite. Variations in habit, morphology and textures correlate with chemical trends expressed as evolving Cl/F ratios, and concentrations of REE + Y (hereafter REY), Sr, Mn, S, Si and Na. Magmatic apatite is unzoned in the dolerite but features core to REY-enriched rim zonation in the granitoids. Increases in Cl- and Sr-contents correlate with rock basicity. Calculation of Cl in the vapour phase relative to melt at the apatite saturation temperature for zoned apatite in the RDG shows higher values for grains with inclusion-rich cores associated with mafic enclaves, concordant with assimilation of exotic material during magma crystallisation. Hydrothermal alteration of magmatic apatite is most varied in the dolerite where interaction with fluids is expressed as subtle changes in Cl- versus F- and REY-enrichment, and most importantly, S-enrichment in

  9. Transformation of apatite phosphorus and non-apatite inorganic phosphorus during incineration of sewage sludge.

    PubMed

    Li, Rundong; Zhang, Ziheng; Li, Yanlong; Teng, Wenchao; Wang, Weiyun; Yang, Tianhua

    2015-12-01

    The recovery of phosphorus from incinerated sewage sludge ash (SSA) is assumed to be economical. Transformation from non-apatite inorganic phosphorus (NAIP) to apatite phosphorus (AP), which has a higher bioavailability and more extensive industrial applications, was studied at 750-950°C by sewage sludge incineration and model compound incineration with a calcium oxide (CaO) additive. Thermogravimetric differential scanning calorimetry analysis and X-ray diffraction measurements were used to analyze the reactions between NAIP with CaO and crystallized phases in SSA. High temperatures stimulated the volatilization of NAIP instead of AP. Sewage sludge incineration with CaO transformed NAIP into AP, and the percentage of AP from the total phosphorus reached 99% at 950°C. Aluminum phosphate reacted with CaO, forming Ca2P2O7 and Ca3(PO4)2 at 750-950°C. Reactions between iron phosphate and CaO occurred at lower temperatures, forming Ca(PO3)2 before reaching 850°C. PMID:26113414

  10. Transformation of apatite phosphorus and non-apatite inorganic phosphorus during incineration of sewage sludge.

    PubMed

    Li, Rundong; Zhang, Ziheng; Li, Yanlong; Teng, Wenchao; Wang, Weiyun; Yang, Tianhua

    2015-12-01

    The recovery of phosphorus from incinerated sewage sludge ash (SSA) is assumed to be economical. Transformation from non-apatite inorganic phosphorus (NAIP) to apatite phosphorus (AP), which has a higher bioavailability and more extensive industrial applications, was studied at 750-950°C by sewage sludge incineration and model compound incineration with a calcium oxide (CaO) additive. Thermogravimetric differential scanning calorimetry analysis and X-ray diffraction measurements were used to analyze the reactions between NAIP with CaO and crystallized phases in SSA. High temperatures stimulated the volatilization of NAIP instead of AP. Sewage sludge incineration with CaO transformed NAIP into AP, and the percentage of AP from the total phosphorus reached 99% at 950°C. Aluminum phosphate reacted with CaO, forming Ca2P2O7 and Ca3(PO4)2 at 750-950°C. Reactions between iron phosphate and CaO occurred at lower temperatures, forming Ca(PO3)2 before reaching 850°C.

  11. Treatability study for WAG 6 (SWSA 6) trench water

    SciTech Connect

    Taylor, P.A.

    1991-08-01

    The Environmental Restoration Program at Oak Ridge National Laboratory (ORNL) is examining methods for remediation and final closure of Waste Area Grouping 6 (WAG 6) under a Resource Conservation and Recovery Act (RCRA) closure plan. WAG 6 consists primarily of Solid Waste Storage Area 6 (SWSA 6), where solid low- level radioactive waste (and some hazardous waste) was buried from 1968 to 1985 in shallow trenches. To support the feasibility study that is being prepared for closure of WAG 6, lab-scale treatability tests were performed on the water from selected trenches in SWSA 6 to determine if the trench water could be treated at the existing wastewater treatment plants at ORNL. Water from 23 of the 500 trenches in SWSA 6 has been sampled and analyzed to date, and the 4 most highly contaminated trenches identified thus far supplied the water used in the treatability tests. The softening and ion-exchange processes used in the Process Wastewater Treatment Plant (PWTP) reduced the {sup 90}Sr concentration, which was the only radionuclide present in the trench water at above the discharge limits, from 260 to 0.2 Bq/L. The air stripping and activated carbon adsorption processes used in the Nonradiological Wastewater Treatment Plant (NRWTP) removed volatile and semivolatile organics (mostly toluene, xylene, and naphthalene), which were the main contaminants in the trench water, to below detection limits. The trench water treated in the lab-scale equipment easily met all discharge limits for the PWTP and the NRWTP. 6 refs., 2 figs., 9 tabs.

  12. The Perils of Electron Microprobe Analysis of Apatite

    NASA Astrophysics Data System (ADS)

    Henderson, C. E.; Essene, E. J.; Wang, K. L.; Zhang, Y.

    2010-12-01

    Accurate electron microprobe analysis of apatite is problematic, especially for F and Cl, whose concentrations are essential in calculating a non-analyzable OH component. The issues include beam-induced sample damage and temporal variation of F and Cl X-rays; both effects are mainly dependent on beam current, beam spot size and apatite orientation [1]. To establish a rigorous analytical procedure, several oriented apatite samples, including the well-known Durango and Wilberforce fluorapatites, were analyzed for a large suite of elements, including oxygen. Careful X-ray spectroscopy was performed, including selection of appropriate analytical standards, background measurement positions and comparison of area peak factors. Polarized infrared spectra on oriented apatite samples were also collected for complementary information. The results show that when apatite samples are oriented with the c-axis parallel to the electron beam, there is significant nonlinear variation (an increase or decrease, depending on measurement conditions) of F and Cl X-ray intensities during analyses, and systematically higher-than-expected F apparent concentrations, despite the careful selection of electron beam conditions from a series of X-ray time scans and zero-time count rate extrapolation. On the other hand, when the electron beam is oriented perpendicular to the c-axis, with a ≤ 15 nA beam current and a ≥ 5 µm diameter defocused beam, F and Cl X-ray intensities do not vary or vary slowly and predictably with time, yielding quantitative analysis results for the Durango and Wilberforce apatites (both containing little OH) which are in good agreement with published wet chemical analyses. Furthermore, the OH and CO2 contents inferred for three other analyzed apatite samples are roughly consistent with infrared analyses. For example, for an apatite from Silver Crater Mine in Ontario, significant deficiency in the P site, as well as extra F, was inferred from microprobe analyses

  13. Oxygen isotope partitioning between phosphate and carbonate in mammalian apatite

    NASA Astrophysics Data System (ADS)

    Daniel Bryant, J.; Koch, Paul L.; Froelich, Philip N.; Showers, William J.; Genna, Bernard J.

    1996-12-01

    The oxygen isotope compositions of phosphate and structural carbonate in mammalian enamel and bone apatite are linked to that of body water at constant body temperature near 37°C, but the isotope systematics of oxygen in structural carbonate are not well understood. Using coupled measurements of the oxygen isotope composition of structural carbonate and phosphate from horse tooth enamel, the apparent oxygen isotope fractionation factor between structural carbonate and body water is estimated to be 1.0263 ± 0.0014. These estimates provide a quantitative basis for using the oxygen isotope composition of structural carbonate in mammalian biogenic apatite for ecological, climatological, and physiological reconstruction.

  14. Composition dependent thermal annealing behaviour of ion tracks in apatite

    NASA Astrophysics Data System (ADS)

    Nadzri, A.; Schauries, D.; Mota-Santiago, P.; Muradoglu, S.; Trautmann, C.; Gleadow, A. J. W.; Hawley, A.; Kluth, P.

    2016-07-01

    Natural apatite samples with different F/Cl content from a variety of geological locations (Durango, Mexico; Mud Tank, Australia; and Snarum, Norway) were irradiated with swift heavy ions to simulate fission tracks. The annealing kinetics of the resulting ion tracks was investigated using synchrotron-based small-angle X-ray scattering (SAXS) combined with ex situ annealing. The activation energies for track recrystallization were extracted and consistent with previous studies using track-etching, tracks in the chlorine-rich Snarum apatite are more resistant to annealing than in the other compositions.

  15. Calibration for Infrared Measurements of OH in Apatite

    NASA Astrophysics Data System (ADS)

    Wang, K. L.; Naab, F.; Zhang, Y.

    2010-12-01

    Apatite is a common accessory mineral, and OH in apatite can indicate the fluid conditions of crystal formation. Previously, water (OH) concentration in apatite has often been estimated through electron microprobe analyses combined with mineral stoichiometry. However, the detection limit, precision, and accuracy of this method are not high. In this work, we calibrated the infrared spectroscopy (IR) method for measurement of OH concentration in apatite by using elastic recoil detection (ERD) analysis to obtain the absolute OH concentration. Large apatite wafers were cut perpendicular to the c-axis of each crystal and doubly polished. ERD measurements were carried out in the Michigan Ion Beam Laboratory at the University of Michigan to determine the hydrogen concentration in each sample. Each ERD spectrum was fitted and a hydrogen standard was used to quantify the hydrogen concentrations. Polarized transmission IR was used on apatite sections that were cut parallel to the c-axis, and doubly polished. IR measurements were made for E-vector parallel to the c-axis. Because the OH peak is intense, very thin samples must be used to avoid absorbance saturation; the thinnest sample (corresponding to the highest OH content) used was 17 µm thick. Four different apatite crystals were successfully analyzed using both the IR and ERD methods. Two were from Durango, Mexico; one from Imilchil, High Atlas Mountains, Morocco; and one from an unknown locality, purchased online from gem dealers. The OH peak near 3550 cm-1 was a relatively simple peak in all four samples. Therefore peak height was used for the absorbance value, A. Using the Beer-Lambert Law, a calibration line was established (R2= 0.95, for IR aperture of 50 µm x 50 µm) where the weight % of H2O is 0.013 times A/d, where d is the thickness in mm. The detection limit of H2O concentration in apatite by IR approaches ppm level for 0.1 mm wafers, the precision is better than 1% relative (depending on H2O content), and

  16. SUMMARY PLAN FOR BENCH-SCALE REFORMER AND PRODUCT TESTING TREATABILITY STUDIES USING HANFORD TANK WASTE

    SciTech Connect

    ROBBINS RA

    2011-02-11

    This paper describes the sample selection, sample preparation, environmental, and regulatory considerations for shipment of Hanford radioactive waste samples for treatability studies of the FBSR process at the Savannah River National Laboratory and the Pacific Northwest National Laboratory.

  17. GUIDE FOR CONDUCTING TREATABILITY STUDIES UNDER CERCLA: THERMAL DESORPTION - INTERIM GUIDANCE

    EPA Science Inventory

    Systematically conducted, well-documented treatability studies are an important component of the remedial investigation/feasibility study (RI/FS) process and the remedial design remedial action (RD/RA) process under the Comprehensive Environmental Response, Compensation, and Liab...

  18. GUIDE FOR CONDUCTING TREATABILITY STUDIES UNDER CERCLA: AEROBIC BIODEGRADATION REMEDY SCREENING

    EPA Science Inventory

    Systematically conducted, well-documented treatability studies are an important component of the remedial investigation/feasibility study (KU FS) process and the remedial design/remedial action (RD/RA) process under the Comprehensive Environmental Response, Compensation, and L...

  19. EPA’s Drinking Water Treatability Database: A Tool for All Drinking Water Professionals

    EPA Science Inventory

    The Drinking Water Treatability Database (TDB) is being developed by the USEPA Office of Research and Development to allow drinking water professionals and others to access referenced information gathered from thousands of literature sources and assembled on one site. Currently, ...

  20. Carbon and oxygen isotopes in apatite CO/sub 2/ and co-existing calcite

    SciTech Connect

    Kolodny, Y.; Kaplan, I. R.

    1981-04-01

    Carbon and oxygen isotopes were analyzed in carbonate apatite CO/sub 2/ and in co-existing calcite. Both C and O in apatite CO/sub 2/ are enriched in the respective light isotopes relative to calcite. These results confirm the proposition that carbonate is part of the apatite structure.

  1. Treatability study Number PDC-1-O-T. Final report

    SciTech Connect

    1998-04-22

    Los Alamos National Laboratory provided treatability study samples from four waste streams, designated Stream {number_sign}1, Stream {number_sign}3, Stream {number_sign}6, and Stream {number_sign}7. Stream {number_sign}1 consisted of one 55-gallon drum of personal protective equipment (PPE), rags, and neutralizing agent (bicarbonate) generated during the cleanup of a sodium dichromate solution spill. Stream {number_sign}3 was one 55-gallon drum of paper, rags, lab utensils, tools, and tape from the decontamination of a glovebox. The sample of Stream {number_sign}6 was packaged in three 30-gallon drums and a 100 ft{sup 3} wooden box. It consisted of plastic sheeting, PPE, and paper generated from the cleanup of mock explosive (barium nitrate) from depleted uranium parts. Stream {number_sign}7 was scrap metal (copper, stainless and carbon steel joined with silver solder) from the disassembly of gas manifolds. The objective of the treatability study is to determine: (1) whether the Perma-Fix stabilization/solidification process can treat the waste sample to meet Land Disposal Restrictions and the Waste Acceptance Criteria for LANL Technical Area 54, Area G, and (2) optimum loading and resulting weight and volume of finished waste form. The stabilized waste was mixed into grout that had been poured into a lined drum. After each original container of waste was processed, the liner was closed and a new liner was placed in the same drum on top of the previous closed liner. This allowed an overall reduction in waste volume but kept waste segregated to minimize the amount of rework in case analytical results indicated any batch did not meet treatment standards. Samples of treated waste from each waste stream were analyzed by Perma-Fix Analytical Services to get a preliminary approximation of TCLP metals. Splits of these samples were sent to American Environmental Network`s mixed waste analytical lab in Cary, NC for confirmation analysis. Results were all below applicable

  2. Inverted Apatite (U-Th)/He and Fission-track Dates from the Rae craton, Baffin Island, Canada and Implications for Apatite Radiation Damage-He Diffusivity Models

    NASA Astrophysics Data System (ADS)

    Ault, A. K.; Reiners, P. W.; Thomson, S. N.; Miller, G. H.

    2015-12-01

    Coupled apatite (U-Th)/He and fission-track (AFT) thermochronology data from the same sample can be used to decipher complex low temperature thermal histories and evaluate compatibility between these two methods. Existing apatite He damage-diffusivity models parameterize radiation damage annealing as fission-track annealing and yield inverted apatite He and AFT dates for samples with prolonged residence in the He partial retention zone. Apatite chemistry also impacts radiation damage and fission-track annealing, temperature sensitivity, and dates in both systems. We present inverted apatite He and AFT dates from the Rae craton, Baffin Island, Canada, that cannot be explained by apatite chemistry or existing damage-diffusivity and fission track models. Apatite He dates from 34 individual analyses from 6 samples range from 237 ± 44 Ma to 511 ± 25 Ma and collectively define a positive date-eU relationship. AFT dates from these same samples are 238 ± 15 Ma to 350 ± 20 Ma. These dates and associated track length data are inversely correlated and define the left segment of a boomerang diagram. Three of the six samples with 20-90 ppm eU apatite grains yield apatite He and AFT dates inverted by 300 million years. These samples have average apatite Cl chemistry of ≤0.02 wt.%, with no correlation between Cl content and Dpar. Thermal history simulations using geologic constraints, an apatite He radiation damage accumulation and annealing model, apatite He dates with the range of eU values, and AFT date and track length data, do not yield any viable time-temperature paths. Apatite He and AFT data modeled separately predict thermal histories with Paleozoic-Mesozoic peaks reheating temperatures differing by ≥15 °C. By modifying the parameter controlling damage annealing (Rmr0) from the canonical 0.83 to 0.5-0.6, forward models reproduce the apatite He date-eU correlation and AFT dates with a common thermal history. Results imply apatite radiation damage anneals at

  3. Biomimetic nanocrystalline apatites: Emerging perspectives in cancer diagnosis and treatment.

    PubMed

    Al-Kattan, Ahmed; Girod-Fullana, Sophie; Charvillat, Cédric; Ternet-Fontebasso, Hélène; Dufour, Pascal; Dexpert-Ghys, Jeannette; Santran, Véronique; Bordère, Julie; Pipy, Bernard; Bernad, José; Drouet, Christophe

    2012-02-14

    Nanocrystalline calcium phosphate apatites constitute the mineral part of hard tissues, and the synthesis of biomimetic analogs is now well-mastered at the lab-scale. Recent advances in the fine physico-chemical characterization of these phases enable one to envision original applications in the medical field along with a better understanding of the underlying chemistry and related pharmacological features. In this contribution, we specifically focused on applications of biomimetic apatites in the field of cancer diagnosis or treatment. We first report on the production and first biological evaluations (cytotoxicity, pro-inflammatory potential, internalization by ZR-75-1 breast cancer cells) of individualized luminescent nanoparticles based on Eu-doped apatites, eventually associated with folic acid, for medical imaging purposes. We then detail, in a first approach, the preparation of tridimensional constructs associating nanocrystalline apatite aqueous gels and drug-loaded pectin microspheres. Sustained releases of a fluorescein analog (erythrosin) used as model molecule were obtained over 7 days, in comparison with the ceramic or microsphere reference compounds. Such systems could constitute original bone-filling materials for in situ delivery of anticancer drugs.

  4. Trace Element Abundances in Extraterrestrial Apatite and Merrillite

    NASA Astrophysics Data System (ADS)

    Ward, D.; Bischoff, A.; Roszjar, J.; Berndt, J.; Whitehouse, M. J.

    2016-08-01

    The trace element abundances (Sc, Ti, V, Cr, Mn, Co, As, Rb, Sr, Y, Zr, Nb, Ba, Hf, Ta, Pb, Th, U, as well as the REE) of 133 apatite and 163 merrillite grains from 24 meteorites, covering 9 different classes were analyzed by LA-ICP-MS and SIMS.

  5. Treatability studies of groundwater contaminated with bis(2-chloroethyl) ether

    SciTech Connect

    Huang, F.Y.C.; Li, K.Y.; Liu, C.C.

    1999-05-01

    The groundwater aquifer underneath a chemical manufacturing plant in Southeast Texas has been contaminated with the leachate from its landfill. There are 17 major chlorinated hydrocarbon contaminants found in the groundwater with concentrations ranging from 1 ppm to 1,200 ppm. An air-stripping unit followed by a thermal catalytic oxidation unit is currently operating on-site to remove all of the chlorinated compounds from the contaminated groundwater. One of the contaminants, bis(2-chloroethyl)ether (DCEE), has a fairly low Henry`s Law constant; therefore, a high air flow rate is employed in the stripping unit to improve the overall stripping efficiency. Nevertheless, the treated groundwater still contains a fair amount of DCEE. An UV-peroxidation reactor is set up to study its feasibility for oxidizing DCEE. The treatability data indicate that DCEE at a concentration of 200 ppm can be oxidized effectively in the presence of H{sub 2}O{sub 2} and the effective UV wavelengths lie between 200 and 280 nm. No noticeable reduction of the oxidation rate is observed at low temperature ({approximately} 11 C). Apparent oxidation rate equations of DCEE are determined and several process design parameters are discussed.

  6. Cerebral creatine deficiencies: a group of treatable intellectual developmental disorders.

    PubMed

    Stockler-Ipsiroglu, Sylvia; van Karnebeek, Clara D M

    2014-07-01

    Currently there are 91 treatable inborn errors of metabolism that cause intellectual developmental disorders. Cerebral creatine deficiencies (CDD) comprise three of these: arginine: glycine amidinotransferase [AGAT], guanidinoacetate methyltransferase [GAMT], and X-linked creatine transporter deficiency [SLC6A8]. Intellectual developmental disorder and cerebral creatine deficiency are the hallmarks of CDD. Additional clinical features include prominent speech delay, autism, epilepsy, extrapyramidal movement disorders, and signal changes in the globus pallidus. Patients with GAMT deficiency exhibit the most severe clinical spectrum. Myopathy is a distinct feature in AGAT deficiency. Guanidinoacetate (GAA) is the immediate product in the creatine biosynthetic pathway. Low GAA concentrations in urine, plasma, and cerebrospinal fluid are characteristic diagnostic markers for AGAT deficiency, while high GAA concentrations are characteristic markers for GAMT deficiency. An elevated ratio of urinary creatine /creatinine excretion serves as a diagnostic marker in males with SLC6A8 deficiency. Treatment strategies include oral supplementation of high-dose creatine-monohydrate for all three CDD. Guanidinoacetate-reducing strategies (high-dose ornithine, arginine-restricted diet) are additionally employed in GAMT deficiency. Supplementation of substrates for intracerebral creatine synthesis (arginine, glycine) has been used additionally to treat SLC6A8 deficiency. Early recognition and treatment improves outcomes. Normal outcomes in neonatally ascertained siblings from index families with AGAT and GAMT deficiency suggest a potential benefit of newborn screening for these disorders.

  7. In situ treatability testing of reductive dechlorination in wetland sediments

    USGS Publications Warehouse

    Lorah, M.M.; Majcher, E.; Jones, E.; Driedger, G.; Dworatzek, S.; Graves, D.

    2005-01-01

    In situ treatability testing was conducted in the discharge wetlands along West Branch Canal Creek at Aberdeen Proving Ground, MD. The potential for stimulating reductive dechlorination of 1,1,2,2-tetrachloroethane, tetrachloroethylene, trichloroethylene, and carbon tetrachloride in areas of preferential discharge or seeps was evaluated. Geological Survey that degrades chlorinated ethanes and ethylenes was tested using MICRO-Trac??? devices. At seep 3-4W, results of the C and BA MICRO-Trac??? treatments showed essentially no biodegradation of chlorinated solvents occurring under natural and bioaugmented conditions. Results of geochemical samples at this site indicated predominantly iron- and sulfate-reducing conditions consistent with the rapid discharge rates previously measured. The biostimulated treatment showed stimulation of methanogenic conditions and partial degradation of the parent chlorinated VOC to intermediate chlorinated compounds. The bioaugmented and bistimulated treatment showed the highest production of methane, the highest removal of parent compounds and intermediate daughter products, and the highest production of the non-chlorinated end product ethylene. This is an abstract of a paper presented at the proceedings of the 8th International In Situ and On-Site Bioremediation Symposium (Baltimore, MD 6/6-9/2005).

  8. Induction Hardening vs Conventional Hardening of a Heat Treatable Steel

    NASA Astrophysics Data System (ADS)

    Sackl, Stephanie; Leitner, Harald; Zuber, Michael; Clemens, Helmut; Primig, Sophie

    2014-11-01

    This study focuses on the comparison of mechanical and microstructural properties of induction and conventionally heat-treated steels in the as-quenched state. The investigated steel is a heat treatable 42CrMo4 steel. In order to characterize the mechanical properties, tensile tests and Vickers hardness tests are performed. The yield strength and hardness of the induction hardened condition turn out to be slightly lower compared to the conventionally hardened one. Light optical and scanning electron microscopy show no differences in the martensitic structure of the induction and conventionally hardened condition. However, electron back scatter diffraction investigations reveal a smaller block size within the conventionally hardened specimen. Carbon mappings by electron probe micro analysis show a homogenous carbon concentration in the conventionally hardened and a non-uniform distribution in the induction-hardened case. The segregation of the carbon exhibits line-type features in the induction hardened condition, lowering the total amount of carbon in the matrix. Therefore, the carbon content in the matrix of the conventionally hardened condition is slightly higher, which causes a smaller block size. The smaller block size is believed to be the reason for the higher hardness and yield strength.

  9. Firm contracts for treatability tests on contaminated soils

    SciTech Connect

    Not Available

    1989-08-01

    Geosafe Corporation, a Pacific Northwest-headquartered hazardous waste remediation company, announced that is has successfully completed treatability testing of contaminated soils under contract with Woodward Clyde Consultants of Denver, Colorado, the prime contractor for a major hazardous waste site in the Western United States. The tests are being conducted at the University of Washington with Geosafe's specially-designed test equipment. The recently concluded testing confirms the ability of Geosafe's patented in situ vitrification (ISV) technology to treat soils containing a variety of organic and inorganic contaminants. ISV, for which Geosafe has worldwide rights, is the only technology available today that will fully comply with the Superfund Amendments and Reauthorization Act. The ability of ISV to treat mixtures of organic, inorganic and radioactive wastes in situ, in a single process, offers distinct advantages over excavation, transportation and incineration. During the ISV process, organic contaminants are pyrolized and the inorganics present are chemically incorporated into the molten soil which, when cooled, resembles naturally-occurring obsidian.

  10. Apatite: a new redox proxy for silicic magmas?

    NASA Astrophysics Data System (ADS)

    Miles, Andrew; Graham, Colin; Hawkesworth, Chris; Gillespie, Martin; Bromiley, Geoff; Hinton, Richard

    2015-04-01

    The oxidation states of magmas provide valuable information about the release and speciation of volatile elements during volcanic eruptions, metallogenesis, source rock compositions, open system magmatic processes, tectonic settings and potentially titanium (Ti) activity in chemical systems used for Ti-dependent geothermometers and geobarometers. In this presentation we explore the use of Mn in apatite as an oxybarometer in intermediate and silicic igneous rocks. Increased Mn concentrations in apatite in granitic rocks from the zoned Criffell granitic pluton (southern Scotland) correlate with decreasing Fe2O3 (Fe3+) and Mn in the whole-rock and likely reflect increased Mn2+/Mn3+and greater compatibility of Mn2+ relative to Mn3+ in apatite under reduced conditions. Fe3+/Fe2+ ratios in biotites have previously been used to calculate oxygen fugacities (fO2) in the outer zone granodiorites and inner zone granites where redox conditions have been shown to change from close to the magnetite-hematite buffer to close to the nickel-nickel oxide buffer respectively[1]. This trend is apparent in apatite Mn concentrations from a range of intermediate to silicic volcanic rocks that exhibit varying redox states and are shown to vary linearly and negatively with log fO2, such that logfO2=-0.0022(±0.0003)Mn(ppm)-9.75(±0.46) Variations in the Mn concentration of apatites appear to be largely independent of differences in the Mn concentration of the melt. Apatite Mn concentrations may therefore provide an independent oxybarometer that is amenable to experimental calibration, with major relevance to studies on detrital mineral suites, particularly those containing a record of early Earth redox conditions, and on the climatic impact of historic volcanic eruptions[2]. [1] Stephens, W. E., Whitley, J. E., Thirlwall, M. F. and Halliday, A. N. (1985) The Criffell zoned pluton: correlated behaviour of rare earth element abundances with isotopic systems. Contributions to Mineralogy and

  11. Apatite as a paleohydrothermal fluid recorder in Carlin-type gold deposits

    NASA Astrophysics Data System (ADS)

    Barker, S. L.; Hickey, K. A.; Dipple, G. M.; Layne, G.

    2009-05-01

    Apatite is a common accessory mineral in most rocks. A variety of trace elements can be substituted into apatite, meaning that apatite has the potential to record changes in the chemistry of ore-forming hydrothermal fluids. This study focuses on variations in apatite texture and chemistry around the world-class Carlin-type Au deposits of NE Nevada. These deposits are characterized by cryptic alteration of calcareous and siliciclastic sedimentary rocks induced by acidic, low-temperature (150-220 °C) ore fluids. A large database of apatite fission track (AFT) samples collected from NE Nevada (Hickey, unpublished data) is being used to examine relationships between apatite fission track ages, textural zonation within apatite crystals and apatite trace element composition. AFT data from "background" samples collected away from hydrothermal mineralization and Cenozoic igneous stocks reveal that regional uplift occurred in the Cretaceous at ~70-60 Ma. In comparison, AFT data from samples around gold mineralization reveal an Eocene heating event, interpreted as the result of hydrothermal reheating by the Carlin Au-forming system (Cline et al., 2005). Optical cathodoluminescence observations reveal that some apatite from Au-bearing material (Eocene AFT age) has embayed cores, and at least four generations of overgrowths (typically ˜10 μm wide overgrowths), which may also be embayed. In comparison, apatite from hydrothermally altered, but unmineralized, material has a single overgrowth generation. 'Background' apatites do not have significant overgrowths. Current research is characterizing the trace element composition of apatite cores and overgrowths via SIMS. We propose that apatite textures and trace element composition record hydrothermal fluid interactions. Applications include using apatite to detect the signature of hydrothermal fluids in rocks cryptically altered by low-temperature hydrothermal systems, or detecting mineralization by examining detrital apatites

  12. Thermodynamic basis for evolution of apatite in calcified tissues (Invited)

    NASA Astrophysics Data System (ADS)

    Navrotsky, A.; Drouet, C.; Rollin-Martinet, S.; Champion, E.; Grossin, D.

    2013-12-01

    Bone remodeling and tooth enamel maturation are biological processes which alter the physico-chemical features of biominerals with time. However, although the ubiquity of bone remodeling is clear, why is well crystallized bone mineral systematically replaced by immature nanocrystalline inorganic material? In enamel, a clear evolution is also seen from the first mineral formed during the secretory stage to its mature well crystalline form, which then changes little in the adult tooth. This contribution provides the thermodynamic basis underlying these biological processes. We determined the energetics of biomimetic apatites corresponding to an increasing degree of maturation. Our data point out the progressive evolution of the enthalpy (ΔHf°) and free energy (ΔGf°) of formation toward more negative values upon maturation. Entropy contributions to ΔGf° values are small compared to enthalpy contributions. ΔHf° varies from -12058.9 × 12.2 to -12771.0 × 21.4 kJ/mol for maturation times increasing from 20 min to 3 weeks, approaching the value for stoichiometric hydroxyapatite, -13431.0 × 22.7 kJ/mol. Apatite thermodynamic stability increases as its composition moved toward stoichiometry. These findings imply diminishing aqueous solubility of calcium and phosphate ions as well as decreased surface reactivity. Such thermodynamically-driven maturation is favorable for enamel maturation since this biomineral must resist external aggressions such as contact with acids. In contrast, maintaining a metastable highly reactive and soluble form of apatite is essential to the effective participation of bone as a source of calcium and phosphate for homeostasis. Therefore our data strongly suggest that, far from being trivial, the intrinsic thermodynamic properties of apatite represent a critical driving force for continuous bone remodeling, in contrast to current views favoring a purely biologically driven cycle. These thermodynamic data may prove helpful in other domains

  13. SUPERFUND TREATABILITY CLEARINGHOUSE: ABSTRACT ON-SITE INCINERATION TESTING OF SHIRCO INFRARED SYSTEMS PORTABLE DEMONSTRATION UNIT-CONTAMINATED SOILS TREATABILITY STUDY

    EPA Science Inventory

    In August of 1986, Shirco was contracted by Dekonta GmbH, a Vest German hazardous waste treatment company, to perform treatability studies at one of the largest dioxin-contaminated sites in the world. The Shirco Infrared process was selected by Dekonta after a two year stud...

  14. SUPERFUND TREATABILITY CLEARINGHOUSE: BENGART AND MEMEL (BENCH-SCALE), GULFPORT (BENCH AND PILOT-SCALE), MONTANA POLE (BENCH-SCALE), AND WESTERN PROCESSING (BENCH-SCALE) TREATABILITY STUDIES

    EPA Science Inventory

    This document presents summary data on the results of various treatability studies (bench and pilot scale), conducted at three different sites where soils were contaminated with dioxins or PCBs. The synopsis is meant to show rough performance levels under a variety of differen...

  15. Dependence of ion concentration in simulated body fluid on apatite precipitation on titania surface

    NASA Astrophysics Data System (ADS)

    Sakaguchi, Akira; Nakano, Masayuki; Hieda, Junko; Ohtake, Naoto; Akasaka, Hiroki

    2015-08-01

    Titanium and its alloys are used as biomaterials, because of their high biocompatibility. Apatite precipitates on a titania surface in vivo, and living bone and titanium alloy are coupled through the thin apatite layer. The initial precipitation behavior of apatite on titania in simulated body fluid (SBF) solutions was evaluated and the effect of inorganic ions in the SBF was investigated. Measurement using the SPR phenomenon was used to evaluate the initial apatite precipitation. An SBF containing approximately equal ion concentrations to those in blood plasma was added to a titania surface and the SPR profile was obtained, from which the initial apatite precipitation rate was found to be 1.14 nm/h. Furthermore, the relationship between the inorganic concentration and the precipitation rate was determined for SBFs with different Na+ and Ca2+ concentrations. Apatite precipitation did not occur in the SBF with a low Na+ concentration, whereas the initial apatite precipitation rate in the SBF that did not contain Ca2+ was 0.32 nm/h. According to these results, Ca2+ has little effect on the initial apatite precipitation. In the initial reaction of apatite precipitation, sodium titanate is formed by the absorption of Na+. Next, calcium titanate precipitates upon the substitution of Na+ with Ca2+. Finally, Na+, phosphate ions and hydroxyl ions are attracted to the surface and apatite is formed. Thus, the rate-limiting factor in the initial nucleation of apatite is the Na+ concentration.

  16. Consideration of grain packing in granular iron treatability studies.

    PubMed

    Firdous, R; Devlin, J F

    2014-08-01

    Commercial granular iron (GI) is light steel that is used in Permeable Reactive Barriers (PRBs). Investigations into the reactivity of GI have focused on its chemical nature and relatively little direct work has been done to account for the effects of grain shape and packing. Both of these factors are expected to influence available grain surface area, which is known to correlate to reactivity. Commercial granular iron grains are platy and therefore pack in preferential orientations that could affect solution access to the surface. Three packing variations were investigated using Connelly Iron and trichloroethylene (TCE). Experimental kinetic data showed reaction rates 2-4 times higher when grains were packed with long axes preferentially parallel to flow (VP) compared to packings with long axes preferentially perpendicular to flow (HP) or randomly arranged (RP). The variations were found to be explainable by variations in reactive sorption capacities, i.e., sorption to sites where chemical transformations took place. The possibility that the different reactive sorption capacities were related to physical pore-scale differences was assessed by conducting an image analysis of the pore structure of sectioned columns. The analyses suggested that pore-scale factors - in particular the grain surface availability, reflected in the sorption capacity terms of the kinetic model used - could only account for a fraction of the observed reactivity differences between packing types. It is concluded that packing does affect observable reaction rates but that micro-scale features on the grain surfaces, rather than the pore scale characteristics, account for most of the apparent reactivity differences. This result suggests that treatability tests should consider the packing of columns carefully if they are to mimic field performance of PRBs to the greatest extent possible.

  17. Thermodynamic Mixing Behavior Of F-OH Apatite Crystalline Solutions

    NASA Astrophysics Data System (ADS)

    Hovis, G. L.

    2011-12-01

    It is important to establish a thermodynamic data base for accessory minerals and mineral series that are useful in determining fluid composition during petrologic processes. As a starting point for apatite-system thermodynamics, Hovis and Harlov (2010, American Mineralogist 95, 946-952) reported enthalpies of mixing for a F-Cl apatite series. Harlov synthesized all such crystalline solutions at the GFZ-Potsdam using a slow-cooled molten-flux method. In order to expand thermodynamic characterization of the F-Cl-OH apatite system, a new study has been initiated along the F-OH apatite binary. Synthesis of this new series made use of National Institute of Standards and Technology (NIST) 2910a hydroxylapatite, a standard reference material made at NIST "by solution reaction of calcium hydroxide with phosphoric acid." Synthesis efforts at Lafayette College have been successful in producing fluorapatite through ion exchange between hydroxylapatite 2910a and fluorite. In these experiments, a thin layer of hydroxylapatite powder was placed on a polished CaF2 disc (obtained from a supplier of high-purity crystals for spectroscopy), pressed firmly against the disc, then annealed at 750 °C (1 bar) for three days. Longer annealing times did not produce further change in unit-cell dimensions of the resulting fluorapatite, but it is uncertain at this time whether this procedure produces a pure-F end member (chemical analyses to be performed in the near future). It is clear from the unit-cell dimensions, however, that the newly synthesized apatite contains a high percentage of fluorine, probably greater than 90 mol % F. Intermediate compositions for a F-OH apatite series were made by combining 2910a hydroxylapatite powder with the newly synthesized fluorapatite in various proportions, then conducting chemical homogenization experiments at 750 °C on each mixture. X-ray powder diffraction data indicated that these experiments were successful in producing chemically homogeneous

  18. Diffusion under irradiation of rare earth elements in apatite

    NASA Astrophysics Data System (ADS)

    Martin, P.; Chevarier, A.; Panczer, G.

    2000-02-01

    Nuclear waste ceramic forms among which the apatite, are under development as an alternative to waste glass in case of selective confinement. In that context, we studied the diffusion of lanthanide ions (La 3+, Eu 3+) in hydroxyapatite over a temperature range of storage interest, taking into account a possible enhanced diffusion due to irradiation effects. The lanthanide ions are introduced in apatite targets using ion implantation. The diffusion coefficients are deduced from Rutherford backscattering spectroscopy (RBS) at each step of annealing and irradiation procedure. Evidence of enhanced diffusion is shown and can be explained as a diffusion process governed by defect migration towards the surface. Time resolved laser-induced fluorescence measurements show that, during enhanced diffusion performed under vacuum, the europium ions substitute the calcium ions preferentially in Ca(I) hydroxyapatite sites.

  19. The biomimetic apatite-cefalotin coatings on modified titanium.

    PubMed

    Kang, Min-Kyung; Lee, Sang-Bae; Moon, Seung-Kyun; Kim, Kwang-Mahn; Kim, Kyoung-Nam

    2012-02-01

    Dental implant failure often occurs due to oral bacterial infection. The aim of this study was to demonstrate that antibiotic efficacy could be enhanced with modified titanium. First, the titanium was modified by anodization and heat-treatment. Then, a biomimetic coating process was completed in two steps. Surface characterization was performed with scanning electron microscopy, energy dispersive spectroscopy, and X-ray diffraction. Release of antibiotic was evaluated by UV/VIS spectrometry, and the antibacterial effect was evaluated on Streptococcus mutans. After the second coating step, we observed a thick homogeneous apatite layer that contained the antibiotic, cefalotin. The titanium formed a rutile phase after the heat treatment, and a carbonated apatite phase appeared after biomimetic coating. We found that the modified titanium increased the loading of cefalotin onto the hydroxyapatite coated surface. The results suggested that modified titanium coated with a cefalotin using biomimetic coating method might be useful for preventing local post-surgical implant infections.

  20. Situ formation of apatite for sequestering radionuclides and heavy metals

    DOEpatents

    Moore, Robert C.

    2003-07-15

    Methods for in situ formation in soil of a permeable reactive barrier or zone comprising a phosphate precipitate, such as apatite or hydroxyapatite, which is capable of selectively trapping and removing radionuclides and heavy metal contaminants from the soil, while allowing water or other compounds to pass through. A preparation of a phosphate reagent and a chelated calcium reagent is mixed aboveground and injected into the soil. Subsequently, the chelated calcium reagent biodegrades and slowly releases free calcium. The free calcium reacts with the phosphate reagent to form a phosphate precipitate. Under the proper chemical conditions, apatite or hydroxyapatite can form. Radionuclide and heavy metal contaminants, including lead, strontium, lanthanides, and uranium are then selectively sequestered by sorbing them onto the phosphate precipitate. A reducing agent can be added for reduction and selective sequestration of technetium or selenium contaminants.

  1. Biomimetic synthesis and biocompatibility evaluation of carbonated apatites template-mediated by heparin.

    PubMed

    Deng, Yi; Sun, Yuhua; Chen, Xiaofang; Zhu, Peizhi; Wei, Shicheng

    2013-07-01

    Biomimetic synthesis of carbonated apatites with good biocompatibility is a promising strategy for the broadening application of apatites for bone tissue engineering. Most researchers were interested in collagen or gelatin-based templates for synthesis of apatite minerals. Inspired by recent findings about the important role of polysaccharides in bone biomineralization, here we reported that heparin, a mucopolysaccharide, was used to synthesize carbonated apatites in vitro. The results indicated that the Ca/P ratio, carbon content, crystallinity and morphology of the apatites varied depending on the heparin concentration and the initial pH value. The morphology of apatite changed from flake-shaped to needle-shaped, and the degree of crystallinity decreased with the increasing of heparin concentration. Biocompatibility of the apatites was tested by proliferation and alkaline phosphatase activity of MC3T3-E1 cells. The results suggested that carbonated apatites synthesized in the presence of heparin were more favorable to the proliferation and differentiation of MC3T3-E1 cells compared with traditional method. In summary, the heparin concentration and the initial pH value play a key role in the chemical constitution and morphology, as well as biological properties of apatites. These biocompatible nano-apatite crystals hold great potential to be applied as bioactive materials for bone tissue engineering.

  2. Removal of lead by apatite and its stability in the presence of organic acids.

    PubMed

    Katoh, Masahiko; Makimura, Akihiko; Sato, Takeshi

    2016-12-01

    In this study, lead sorption and desorption tests were conducted with apatite and organic acids (i.e. citric, malic, and formic acids) to understand lead removal by apatite in the presence of an organic acid and lead dissolution from the lead- and organic-acid-sorbed apatite by such organic acid exposure. The lead sorption test showed that the amount of lead removed by apatite in the presence of organic acid varied depending on the type of acid used. The molar amounts of calcium dissolved from apatite in the presence and absence of organic acid were exactly the same as those of lead removed even under different pH conditions as well as different organic acid concentrations, indicating that the varying amount of lead removal in the presence of different organic acids resulted from the magnitude of the dissolution of apatite and the precipitation of lead phosphate minerals. The percentages of lead dissolved from the organic-acid-sorbed and non-organic-acid-sorbed apatite by all the organic acid extractions were equal and higher than those by water extraction. In particular, the highest extractions were observed in the non-organic-acid-sorbed apatite by citric and malic acids. These results suggest that to immobilize lead by the use of apatite in the presence of organic acids, much more apatite must be added than in the absence of organic acid, and that measures must be taken to ensure that the immobilized lead is not dissolved.

  3. Crystal Chemistry of Carbonate Apatites from High-Pressure Synthesis

    NASA Astrophysics Data System (ADS)

    Fleet, M. E.; Liu, X.

    2007-12-01

    Relatively large (50-200 μm) crystals of carbonate-bearing hydroxylapatite (CHAP) and fluorapatite (CFAP) have been grown from carbonate-rich melts at 1-3 GPa and used to determine structural details beyond the resolution of Rietveld powder diffraction methods, using X-ray single-crystal structure and FTIR spectroscopy. The new information includes the structural location of the channel (type A) and phosphate group (type B) carbonate ions in various composition series, as well as the location of the excess fluoride anion in francolite, substitution mechanisms, and identification of the hydrogen carbonate (bicarbonate) ion as a new apatite channel species. For equivalent conditions of synthesis, the uptake of A-B carbonate is greater for Na-bearing CHAP (up to 2 carbonate ions pfu) than Na-bearing CFAP (about 0.4 pfu). The Na cation and A and B carbonate ions are locally coupled in ratios of 1:1:1 in CHAP and 1:1:2 in CFAP, to minimize the effects of charge compensation and spatial accommodation. An extensive data base of type A and B site occupancies reveals that the amount of A carbonate in type A-B CHAP and CFAP is considerably under represented by the relative band areas for asymmetric stretching (ν3) and out-of-plane bending (ν2) of carbonate in FTIR spectra. The weaker absorption intensity and shift to higher wavenumbers of type A bands indicates that the carbonate ion is bound more weakly in the apatite channel than in the interior of the crystal structure. Thus literature spectra for apatites, and especially for apatite biomineralisation, showing dominant amounts of B carbonate should be re-evaluated.

  4. Apatite fission-track thermochronology of the Pennsylvania Appalachian Basin

    NASA Astrophysics Data System (ADS)

    Roden, Mary K.; Miller, Donald S.

    1989-09-01

    Thirty-four apatite fission-track apparent ages and twenty-four track length distributions for ash bed samples from the Valley and Ridge Province and Upper Devonian to Upper Pennsylvania sedimentary samples from the Allegheny Front and Allegheny Plateau of Pennsylvania suggest that these regions represent different thermal (uplift) regimes as well as different structural provinces. The Valley and Ridge Province Tioga and Kalkberg ash bed samples yield apatite fission-track apparent ages and track length distributions that indicate early post-Alleghanian (285-270 Ma) cooling and unroofing that began at ˜250 Ma. Assuming a geothermal gradient of 25°C km -1, a burial depth of at least 3.4 km can be estimated for all the Pennsylvania samples. At the Allegheny structural front and on the western Allegheny Plateau, the apatite fission-track apparent ages (<150 Ma) and track length measurements indicate a Late Jurassic-Early Cretaceous thermal event for these samples possibly resulting from a higher geothermal gradient coinciding with kimberlite intrusion at this time along the Greene-Potter Fault Zone. In northeast Pennsylvania on the Allegheny Plateau, the Upper Paleozoic sedimentary samples yield apatite fission-track apparent ages ≤180 Ma. Narrow track length distributions with long mean lengths (13-14 μm) and small standard deviations (1.3 μm) suggest rapid cooling from temperatures >110°C during the Middle Jurassic-Early Cretaceous for this part of Pennsylvania. This is consistent with the suggested uplift history of the Catskill Mountain region in adjacent New York State.

  5. Characterization of apatite formed on alkaline-heat-treated Ti.

    PubMed

    Chosa, N; Taira, M; Saitoh, S; Sato, N; Araki, Y

    2004-06-01

    Alkaline-heat-treated titanium self-forms an apatite surface layer in vivo. The aim of the present study was to materialistically characterize the surface of alkaline-heat-treated titanium immersed in simulated body fluid (AHS-TI) and to examine the differentiation behavior of osteoblasts on AHS-TI. SEM, thin-film XRD, FTIR, and XPS analyses revealed that AHS-TI contained a 1.0- micro m-thick, low-crystalline, and [002] direction-oriented carbonate apatite surface. Human osteoblast-like SaOS-2 cells were cultured on polystyrene, titanium, and AHS-TI, and RT-PCR analyses of osteogenic differentiation-related mRNAs were conducted. On AHS-TI, the expression of bone sialoprotein mRNA was up-regulated as compared with that on polystyrene and titanium (p < 0.05). On AHS-TI, the expression of osteopontin and osteocalcin mRNAs was up-regulated as compared with that on polystyrene (p<0.05). The results indicate that the apatite was bone-like and accelerated the osteogenic differentiation of SaOS-2, suggesting that alkaline-heat treatment might facilitate better integration of titanium implants with bone.

  6. Trace element partitioning between apatite and silicate melts

    NASA Astrophysics Data System (ADS)

    Prowatke, Stefan; Klemme, Stephan

    2006-09-01

    We present new experimental apatite/melt trace element partition coefficients for a large number of trace elements (Cs, Rb, Ba, La, Ce, Pr, Sm, Gd, Lu, Y, Sr, Zr, Hf, Nb, Ta, U, Pb, and Th). The experiments were conducted at pressures of 1.0 GPa and temperatures of 1250 °C. The rare earth elements (La, Ce, Pr, Sm, Gd, and Lu), Y, and Sr are compatible in apatite, whereas the larger lithophile elements (Cs, Rb, and Ba) are strongly incompatible. Other trace elements such as U, Th, and Pb have partition coefficients close to unity. In all experiments we found DHf > DZr, DTa ≈ DNb, and DBa > DRb > DCs. The experiments reveal a strong influence of melt composition on REE partition coefficients. With increasing polymerisation of the melt, apatite/melt partition coefficients for the rare earth elements increase for about an order of magnitude. We also present some results in fluorine-rich and water-rich systems, respectively, but no significant influence of either H 2O or F on the partitioning was found. Furthermore, we also present experimentally determined partition coefficients in close-to natural compositions which should be directly applicable to magmatic processes.

  7. Materials testing for in situ stabilization treatability study of INEEL mixed wastes soils

    SciTech Connect

    Heiser, J.; Fuhrmann, M.

    1997-09-01

    This report describes the contaminant-specific materials testing phase of the In Situ Stabilization Comprehensive Environment Response, Compensation, and Liability Act (CERCLA) Treatability Study (TS). The purpose of materials testing is to measure the effectiveness of grouting agents to stabilize Idaho National Engineering and Environmental Laboratory (INEEL) Acid Pit soils and select a grout material for use in the Cold Test Demonstration and Acid Pit Stabilization Treatability Study within the Subsurface Disposal Area (SDA) at the Radioactive Waste Management Complex (RWMC). Test results will assist the selecting a grout material for the follow-on demonstrations described in Test Plan for the Cold Test Demonstration and Acid Pit Stabilization Phases of the In Situ Stabilization Treatability Study at the Radioactive Waste Management Complex.

  8. Field Emission Electron Microprobe Analysis of Halogens in Apatite

    NASA Astrophysics Data System (ADS)

    Tacker, R. C.

    2011-12-01

    Field emission electron microprobe is capable of higher resolution and lower voltage than other microprobes, making it an ideal instrument for analysis of small accessory minerals in thin section such as apatite. In this study, the field emission electron microprobe was evaluated for analysis of fluorine and chlorine in apatite. Analysis was conducted on (001), (100) and an intermediate section of natural apatite crystals, using the JEOL JXA-8530F Hyperprobe, located at Fayetteville State University in Fayetteville, North Carolina. Conditions were beam current of 10 nanoamps, accelerating voltages from 5-20 kV, and spot sizes from 1-10 micrometers. Very short counting times were used, some as little as 2 seconds. Analytical strategies exploited the fact that excitation energies for fluorine Kα are much lower than for chlorine. Earlier studies (e.g. Stormer et al. 1993; Fialin and Chopin, 2006) documented the complex behavior of beam-driven migration, subsurface accumulation and desorption during fluorine analysis. The cumulative effect is increase and then fall of count rates with time and repeated analysis. The details of earlier studies were reproduced: (1) Apatite analysis by electron microprobe has two additional unknown variables, which are the crystallographic orientation of the unknown and of the standard. (2) The most reliable measure of fluorine cps is derived from a regression to zero time, accounting for crystal orientation; (3) Changing the analytical conditions (accelerating voltage, spot size, duration of analysis) changes only the time scale over which migration and desorption take place. New results from the JEOL Hyperprobe show that, for all crystal orientations, initial fluorine cps increase from 5 and 7 kV to 10 kV, but decrease systematically with further increases in kV, interpreted as loss of fluorine without concomitant excitation of X-rays. To date, fluorine analysis is routinely conducted at 15 and 20 kV. In contrast, chlorine initial

  9. Partition coefficients of Hf, Zr, and REE between zircon, apatite, and liquid

    USGS Publications Warehouse

    Fujimaki, H.

    1986-01-01

    Concentration ratios of Hf, Zr, and REE between zircon, apatite, and liquid were determined for three igneous compositions: two andesites and a diorite. The concentration ratios of these elements between zircon and corresponding liquid can approximate the partition coefficient. Although the concentration ratios between apatite and andesite groundmass can be considered as partition coefficients, those for the apatite in the diorite may deviate from the partition coefficients. The HREE partition coefficients between zircon and liquid are very large (100 for Er to 500 for Lu), and the Hf partition coefficient is even larger. The REE partition coefficients between apatite and liquid are convex upward, and large (D=10-100), whereas the Hf and Zr partition coefficients are less than 1. The large differences between partition coefficients of Lu and Hf for zircon-liquid and for apatite-liquid are confirmed. These partition coefficients are useful for petrogenetic models involving zircon and apatite. ?? 1986 Springer-Verlag.

  10. Potential routes to carbon inclusion in apatite minerals: a DFT study

    NASA Astrophysics Data System (ADS)

    Rabone, J. A. L.; de Leeuw, N. H.

    2007-09-01

    We have conducted a computational study to investigate a number of possible routes for the incorporation of carbon into apatites. Using density functional theory (DFT) we have calculated geometry optimised structures for fluor- and hydroxy-apatites with and without various substitutions. We have studied several different carbonate substitutions, pure carbonate and pure formate apatites, neutral carbon atoms occupying interstices, and carbon dioxide and acetylene absorbed in oxyapatite.

  11. Molecular functionalization of tantalum oxide surface towards development of apatite growth

    NASA Astrophysics Data System (ADS)

    Aubry, D.; Volcke, C.; Arnould, Ch.; Humbert, C.; Thiry, P. A.; Delhalle, J.; Mekhalif, Z.

    2009-02-01

    We have studied the apatite growth dynamics on tantalum oxide surfaces. This nucleation is obtained via an organosilane intermediate layer between the apatite and the substrate surface. Four organosilane layers (differing by their terminal functionality) were investigated. Their characterization with atomic force microscopy and other techniques such as X-ray photoelectron spectroscopy (XPS) and wetting measurements highlighted the influence of the organosilane terminal groups on the apatite growth rates. Results revealed that apatite is indeed growing faster on phosphate terminal groups than on the three other groups studied (vinyl, hydroxyl and carboxyl).

  12. Lu-Hf and PbSL geochronology of apatites from Proterozoic terranes: A first look at Lu-Hf isotopic closure in metamorphic apatite

    NASA Astrophysics Data System (ADS)

    Barfod, Gry Hoffmann; Krogstad, Eirik Jens; Frei, Robert; Albarède, Francis

    2005-04-01

    The mineral apatite is characterized by elevated and highly variable Lu/Hf ratios that, in some cases, allow for single-crystal dating by the Lu-Hf isotopic system. Apatites from the Adirondack Lowlands and Otter Lake area in the Grenville Province, and from the Black Hills, South Dakota, yield Lu-Hf ages that are consistently older than their respective Pb step leaching ages. Isotopic closure for the Lu-Hf system, therefore, occurs before U-Pb system closure in this mineral. In the Adirondack Lowlands, where H 2O activity was low, Lu-Hf systematics of cm-sized apatite crystals remained undisturbed during upper amphibolite facies metamorphism (˜700 to 675 °C) at 1170-1130 Ma. The relatively old Lu-Hf ages of 1270 and 1230 Ma observed for these apatites correlate with decreasing crystal size. In contrast, apatite from the fluid-rich Otter Lake area and Black Hills yields unrealistically low apparent Lu-Hf closure temperatures, implying that in these apatites, fluids facilitated late exchange. The Lu-Hf ages for the metamorphic apatites were thus controlled either by the prevailing temperature and grain size, or by fluid activity.

  13. In-Situ Chemical Reduction and Oxidation of VOCs in Groundwater: Groundwater Treatability Studies

    NASA Technical Reports Server (NTRS)

    Keith, Amy; Glasgow, Jason; McCaleh, Rececca C. (Technical Monitor)

    2001-01-01

    This paper presents NASA Marshall Space Flight Center's treatability studies for volatile organic compounds in groundwater. In-Situ groundwater treatment technologies include: 1) Chemical Reduction(Ferox); 2) Chemical Oxidation (Fenton Reagents, Permanganate, and Persulfate); and 3) Thermal (Dynamic Underground Stripping, Six-Phase Heating). This paper is presented in viewgraph form.

  14. SUPERFUND TREATABILITY CLEARINGHOUSE: TRIAL BURN TEST REPORT, PART 1 - DATA SUMMARIES

    EPA Science Inventory

    This treatability study summary reports on the results of a trial burn of pesticide-contaminated soil from the Aberdeen, NC Superfund site. The trial burn using the Vesta mobile rotary kiln incinerator was designed to demonstrate that this system can destroy the pestici...

  15. Innovative Approach for Development of Drinking Water Research Data in the EPA Treatability Database

    EPA Science Inventory

    In recent years, funding for development of the TDB has been limited due to Federal budget constraints. As a result, EPA adopted an innovative approach to continue the development of new contaminants and maintenance of treatability information on over 60 existing drinking water ...

  16. GUIDE TO CONDUCTING TREATABILITY STUDIES UNDER CERCLA: SOIL WASHING - INTERIM GUIDANCE

    EPA Science Inventory

    Systematically conducted, well-documented treatability studies are an important component of the remedial investigation/feasibility study (RI/FS) process and the remedial design/remedial action (RD/RA) process under the Comprehensive Environmental Response, Compensation, and Liab...

  17. GUIDE FOR CONDUCTING TREATABILITY STUDIES UNDER CERCLA: SOLVENT EXTRACTION - INTERIM GUIDANCE

    EPA Science Inventory

    Systematically conducted, well-documented treatability studies are an important component of the remedial investigation/feasibility study (RI/FS) process and the remedial design/remedial action (RD/RA) process under the Comprehensive Environmental Response, Compensation and Liabi...

  18. SUPERFUND TREATABILITY CLEARINGHOUSE: INPUT/OUTPUT DATA FOR SEVERAL TREATMENT TECHNOLOGIES

    EPA Science Inventory

    This treatability study is a pilot-scale evaluation of a thin-film evaporator (TFE) for volatile organics (VO) removal from oily sludges such as refinery sludges. TFEs were studied to evaluate their use to remove and recover VO from these sludges prior to land treatment. This w...

  19. SUPERFUND TREATABILITY CLEARINGHOUSE: CERCLA BDAT SARM PREPARATION AND RESULTS OF PHYSICAL SOILS WASHING EXPERIMENTS (FINAL REPORT)

    EPA Science Inventory

    This study reports on the results of work preparing 30,000 Ibs of SARM or synthetic analytical reference matrix, a surrogate Superfund soil containing a vide range of contaminants. It also reports the results ©f bench scale treatability experiments designed to simulate the EP...

  20. Thermal expansion of solid solutions in apatite binary systems

    SciTech Connect

    Knyazev, Alexander V.; Bulanov, Evgeny N. Korokin, Vitaly Zh.

    2015-01-15

    Graphical abstract: Thermal dependencies of volume thermal expansion parameter for with thermal expansion diagrams for Pb{sub 5}(PO{sub 4}){sub 3}F{sub x}Cl{sub 1−x}. - Highlights: • Solid solutions in three apatitic binary systems were investigated via HT-XRD. • Thermal expansion coefficients of solid solutions in the systems were calculated. • Features of the thermal deformation of the apatites were described. • Termoroentgenography is a sensitive method for the investigation of isomorphism. - Abstract: High-temperature insitu X-ray diffraction was used to investigate isomorphism and the thermal expansion of apatite-structured compounds in three binary systems in the entire temperature range of the existence of its hexagonal modifications. Most of the studied compounds are highly expandable (α{sub l} > 8 × 10{sup 6} (K{sup −1})). In Pb{sub 5}(PO{sub 4}){sub 3}F–Pb{sub 5}(PO{sub 4}){sub 3}Cl system, volume thermal expansion coefficient is independence from the composition at 573 K. In Pb{sub 5}(PO{sub 4}){sub 3}Cl–Pb{sub 5}(VO{sub 4}){sub 3}Cl, the compound with equimolar ratio of substituted atoms has constant volume thermal expansion coefficient in temperature range 298–973 K. Ca{sub 5}(PO{sub 4}){sub 3}Cl–Pb{sub 5}(PO{sub 4}){sub 3}Cl system is characterized by the most thermal sensitive composition, in which there is an equal ratio of isomorphic substituted atoms.

  1. H-Isotopic Composition of Apatite in Northwest Africa 7034

    NASA Technical Reports Server (NTRS)

    McCubbin, F. M.; Barnes, J. J.; Santos, A. R.; Boyce, J. W.; Anand, M.; Franchi, I. A.; Agee, C. B.

    2016-01-01

    Northwest Africa (NWA) 7034 and its pairings comprise a regolith breccia with a basaltic bulk composition [1] that yields a better match than any other martian meteorite to estimates of Mars' bulk crust composition [1]. Given the similarities between NWA 7034 and the martian crust, NWA 7034 may represent an important sample for constraining the crustal composition of components that cannot be measured directly by remote sensing. In the present study, we seek to constrain the H isotopic composition of the martian crust using Cl-rich apatite in NWA 7034.

  2. Developing biogeochemical tracers of apatite weathering by ectomycorrhizal fungi

    NASA Astrophysics Data System (ADS)

    Vadeboncoeur, M. A.; Bryce, J. G.; Hobbie, E. A.; Meana-Prado, M. F.; Blichert-Toft, J.

    2012-12-01

    Chronic acid deposition has depleted calcium (Ca) from many New England forest soils, and intensive harvesting may reduce phosphorus (P) available to future rotations. Thin glacial till soils contain trace amounts of apatite, a primary calcium phosphate mineral, which may be an important long-term source of both P and Ca to ecosystems. The extent to which ECM fungi enhance the weathering rate of primary minerals in soil which contain growth-limiting nutrients remains poorly quantified, in part due to biogeochemical tracers which are subsequently masked by within-plant fractionation. Rare earth elements (REEs) and Pb isotope ratios show some potential for revealing differences in soil apatite weathering rates across forest stands and silvicultural treatments. To test the utility of these tracers, we grew birch seedlings semi-hydroponically under controlled P-limited conditions, supplemented with mesh bags containing granite chips. Our experimental design included nonmycorrhizal (NM) as well as ectomycorrhizal cultures (Cortinarius or Leccinum). Resulting mycorrhizal roots and leachates of granite chips were analyzed for these tracers. REE concentrations in roots were greatly elevated in treatments with granite relative to those without granite, demonstrating uptake of apatite weathering products. Roots with different mycorrhizal fungi accumulated similar concentrations of REEs and were generally elevated compared to the NM cultures. Ammonium chloride leaches of granite chips grown in contact with mycorrhizal hyphae show elevated REE concentrations and significantly radiogenic Pb isotope signatures relative to bulk rock, also supporting enhanced apatite dissolution. Our results in culture are consistent with data from field-collected sporocarps from hardwood stands in the Bartlett Experimental Forest in New Hampshire, in which Cortinarius sporocarp Pb isotope ratios were more radiogenic than those of other ectomycorrhizal sporocarps. Taken together, the experimental

  3. Pilot-scale treatability test plan for the 200-UP-1 groundwater Operable Unit

    SciTech Connect

    Wittreich, C.D.

    1994-05-01

    This document presents the treatability test plan for pilot-scale pump and treat testing at the 200-UP-1 Operable Unit. This treatability test plan has been prepared in response to an agreement between the US Department of Energy, the US Environmental Protection Agency, and the Washington State Department of Ecology, as documented in Hanford Federal Facility Agreement and Consent Order (Ecology et al. 1989a) Change Control Form M-13-93-03 (Ecology et al. 1994). The agreement also requires that, following completion of the activities described in this test plan, a 200-UP-1 Operable Unit interim remedial measure (IRM) proposed plan be developed for use in preparing an interim action record of decision (ROD). The IRM Proposed Plan will be supported by the results of the testing described in this treatability test plan, as well as by other 200-UP-1 Operable Unit activities (e.g., limited field investigation, development of a qualitative risk assessment). Once issued, the interim action ROD will specify the interim action for groundwater contamination at the 200-UP-1 Operable Unit. The approach discussed in this treatability test plan is to conduct a pilot-scale pump and treat test for the contaminant plume associated with the 200-UP-1 Operable Unit. Primary contaminants of concern are uranium and technetium-99; the secondary contaminant of concern is nitrate. The pilot-scale treatability testing presented in this test plan has as its primary purpose to assess the performance of aboveground treatment systems with respect to the ability to remove the primary contaminants in groundwater withdrawn from the contaminant plume.

  4. Survey of commercial firms with mixed-waste treatability study capability

    SciTech Connect

    McFee, J.; McNeel, K.; Eaton, D.; Kimmel, R.

    1996-04-01

    According to the data developed for the Proposed Site Treatment Plans, the US Department of Energy (DOE) mixed low-level and mixed transuranic waste inventory was estimated at 230,000 m{sup 3} and embodied in approximately 2,000 waste streams. Many of these streams are unique and may require new technologies to facilitate compliance with Resource Conservation and Recovery Act disposal requirements. Because most waste streams are unique, a demonstration of the selected technologies is justified. Evaluation of commercially available or innovative technologies in a treatability study is a cost-effective method of providing a demonstration of the technology and supporting decisions on technology selection. This paper summarizes a document being prepared by the Mixed Waste Focus Area of the DOE Office of Science and Technology (EM-50). The document will provide DOE waste managers with a list of commercial firms (and universities) that have mixed-waste treatability study capabilities and with the specifics regarding the technologies available at those facilities. In addition, the document will provide a short summary of key points of the relevant regulations affecting treatability studies and will compile recommendations for successfully conducting an off-site treatability study. Interim results of the supplier survey are tabulated in this paper. The tabulation demonstrates that treatment technologies in 17 of the US Environmental Protection Agency`s technology categories are available at commercial facilities. These technologies include straightforward application of standard technologies, such as pyrolysis, as well as proprietary technologies developed specifically for mixed waste. The paper also discusses the key points of the management of commercial mixed-waste treatability studies.

  5. Commercial treatability study capabilities for application to the US Department of Energy`s anticipated mixed waste streams. Revision 1

    SciTech Connect

    1996-09-01

    US DOE mixed low-level and mixed transuranic waste inventory was estimated at 181,000 cubic meters (about 2,000 waste streams). Treatability studies may be used as part of DOE`s mixed waste management program. Commercial treatability study suppliers have been identified that either have current capability in their own facilities or have access to licensed facilities. Numerous federal and state regulations, as well as DOE Order 5820.2A, impact the performance of treatability studies. Generators, transporters, and treatability study facilities are subject to regulation. From a mixed- waste standpoint, a key requirement is that the treatability study facility must have an NRC or state license that allows it to possess radioactive materials. From a RCRA perspective, the facility must support treatability study activities with the applicable plans, reports, and documentation. If PCBs are present in the waste, TSCA will also be an issue. CERCLA requirements may apply, and both DOE and NRC regulations will impact the transportation of DOE mixed waste to an off-site treatment facility. DOE waste managers will need to be cognizant of all applicable regulations as mixed-waste treatability study programs are initiated.

  6. Apatite coating on anionic and native collagen films by an alternate soaking process.

    PubMed

    Góes, J C; Figueiró, S D; Oliveira, A M; Macedo, A A M; Silva, C C; Ricardo, N M P S; Sombra, A S B

    2007-09-01

    The present study focuses on apatite coating on collagen films, with various different densities of carboxyl groups, using an alternate soaking process. Anionic collagen (AC), which has different densities of carboxylic groups compared to native collagen (NC), was obtained by hydrolysis of carboxyamides of asparagine and glutamine residues. From X-ray diffraction analysis, apatite was found to be coated on AC and NC films. Peaks ascribed to apatite were observed at 26 degrees and 32 degrees in the diffraction patterns of hydroxyapatite crystals. The amount of apatite coated on both AC and NC collagen films continued to increase up to 100 reaction cycles. However, there is a significant difference in apatite coating between the two films. The amount of apatite formed on the surface of AC film increased 1.24 times faster than on NC film. The scanning electron photomicrograph images of the mineralized NC and the AC film coatings formed after 100cycles show that regular porous apatite coating had formed within the collagen fibrils. These results suggest that the higher content of carboxyl groups in AC plays an effective role in the heterogeneous nucleation of apatite in the body environment.

  7. Lepidocrocite, an apatite mineral, and magnetic in teeth of chitons (Polyplacophora).

    PubMed

    Lowenstam, H A

    1967-06-01

    X-ray diffraction patterns show that the mature denticles of three extant chiton species are composed of the mineral lepidocrocite and an apatite mineral, probably francolite, in addition to magnetite. Each of the three minerals forms a discrete microarchitectural unit of the chiton denticles. This is the first indication that lepidocrocite is precipitated by marine organisms and an apatite mineral by chitons.

  8. TREATMENT OF ACID MINE DRAINAGE USING FISHBONE APATITE IITM

    SciTech Connect

    Neal A. Yancey

    2006-10-01

    ABSTRACT. In 2000, a reactive barrier was installed on the East Fork of Ninemile Creek near Wallace, Idaho to treat acid mine discharge. The barrier was filled with fishbone derived Apatite IITM to remove the contaminants of concern (Zn, Pb, and Cd) and raise the pH of the acidic mine discharge. Metal removal has been achieved by a combination of chemical, biological, and physical precipitation. Flow for the water ranges from 5 to 35 gallons per minute. The water is successfully being treated, but the system experienced varying degrees of plugging. In 2002, gravel was mixed with the Apatite IITM to help control plugging. In 2003 the Idaho National Laboratory was ask to provide technical support to the Coeur d’Alene Basin Commission to help identify a remedy to the plugging issue. Air sparging was employed to treat the plugging issues. Plastic packing rings were added in the fall of 2005, which have increased the void space in the media and increased flows during the 10 months of operation since the improvements were made.

  9. Structural characterization of nano-sized calcium deficient apatite powders.

    PubMed

    Liou, Sz-Chian; Chen, San-Yuan; Lee, Hsin-Yi; Bow, Jong-Shing

    2004-01-01

    Nano-sized calcium-deficient apatitic (CDHA) crystals with Ca/P ratios from 1.5 to 1.67 were synthesized using wet chemical method and of needle-like shape with 5-10 nm in diameter and 40-50 nm in length was observed. The structural environment of the Ca atoms in all the CDHA nano-crystals has been investigated using EXAFS, XANES and EELS. The results reveal that a maximum Fourier transform amplitude occurs at the apatite with a Ca/P ratio of 1.67 and the structural disorder increase following the sequence of 1.67>1.5>1.6>1.55. A similar phenomenon is also observed in both K-edge XANES and L(2,3)-edge ELNES in the Ca atom. The structural analysis further demonstrates that different chemical and biological properties among these CDHA nano-crystals with Ca/P ratio from 1.5 to 1.67 are primarily due to the effect of stoichiometry and non-stoichiometry as compared to the structural order-disorder.

  10. Apatite formation on dental ceramics modified by a bioactive glass.

    PubMed

    Kontonasaki, E; Papadopoulou, L; Zorba, T; Pavlidou, E; Paraskevopoulos, K; Koidis, P

    2003-09-01

    Restorative dental materials are considered biocompatible without exhibiting any bioactive behaviour. The aim of this study was the investigation of surface structure changes on conventional dental ceramics used in metal-ceramic restorations modified by a bioactive glass, after immersion in SBF for various time periods. Bioactive glass powder was mixed with porcelain powder with three different weight ratios: 1:1, 1:2, and 2:1. The two powders were mixed with porcelain modelling liquid and the mixture was transferred and spread on the surface of pre-fabricated ceramic disks. Coated ceramic specimens after being exposed to a specific thermal cycle as it is recommended for dental ceramics were soaked in Simulated Body Fluid (SBF) at 37 degrees C for various periods of time. After soaking, specimens were studied using Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopy (EDS). Results revealed the development of a non-stoichiometric, biological apatite layer on their surface after exposure in SBF for several time periods. The onset of apatite-layer formation is directly dependent on the amount of bioglass in the coating and its thickness reduces within the specimens of the same bioactive glass-porcelain proportion with time, reaching an average thickness of 15 microm at the longest immersion time, for all the specimens.

  11. Fluoride incorporation into apatite crystals delays amelogenin hydrolysis

    PubMed Central

    DenBesten, Pamela; Zhu, Li; Li, Wu; Tanimoto, Kotaro; Liu, Haichuan; Witkowska, Halina Ewa

    2012-01-01

    Enamel fluorosis has been related to an increase in the amount of amelogenin in fluorosed enamel as compared to normal enamel in the maturation stage. In this study we tested the hypothesis that fluoride incorporated into carbonated apatite alters amelogenin hydrolysis. Recombinant human amelogenin (rh174) was allowed to bind to 0.15 mg of carbonated hydroxyapatite (CAP) or fluoride-containing carbonated hydroxyapatite (F-CAP) synthesized to contain 100, 1000 or 4000 ppm F-. After 3 h digestion with recombinant human MMP20 or KLK4, bound protein was characterized by reverse-phase HPLC. Proteolytic fragments formed after 24 h digestion of amelogenin, were identified by LC tandem mass spectrometry (LCMS/MS). The hydrolysis of amelogenin bound to F100-CAP by both MMP20 and KLK4 was significantly reduced in a dose dependent manner as compared to CAP. After 24 h hydrolysis, the number of cleavage sites in bound amelogenin by MMP20 were similar in CAP and F100-CAP, whereas there were 24 fewer cleavage sites identified for the KLK4 hydrolysis on F100-CAP as compared to CAP. These results suggest that the reduced hydrolysis of amelogenins in fluorosed enamel may be partially due to the increased fluoride content in fluoride containing apatite, contributing to the hypomineralized enamel matrix phenotype observed in fluorosed enamel. PMID:22243219

  12. Bone formation ability of carbonate apatite-collagen scaffolds with different carbonate contents.

    PubMed

    Matsuura, Ayumu; Kubo, Takayasu; Doi, Kazuya; Hayashi, Kazuhiko; Morita, Kouji; Yokota, Rie; Hayashi, Hidetaka; Hirata, Isao; Okazaki, Masayuki; Akagawa, Yasumasa

    2009-03-01

    Hydroxyapatite and carbonate apatites with different carbonate contents were synthesized, mixed with atelocollagen, and made into sponge scaffolds. The scaffolds were implanted into the bone sockets of the femurs of male New Zealand white rabbits for 2, 3, 12 and 24 weeks. carbonate apatite-collagen scaffold with 4.8 wt% carbonate content appeared to have similar crystallinity and chemical composition to human bone. When the scaffolds were implanted into the rabbit femurs, histological observation indicated that the carbonate apatites-collagen scaffolds with relatively higher carbonate contents were gradually deformed throughout the implantation period, and showed uniform surrounding bone after 24 weeks and could not be distinguished. The carbonate apatite-collagen scaffold with 4.8 wt% carbonate content showed the highest bone area ratio of all of the scaffolds. It is suggested that a carbonate apatite-collagen scaffold with carbonate content similar to that of human bone may have optimal bone formation ability.

  13. Apatite precipitation on a novel fast-setting calcium silicate cement containing fluoride

    PubMed Central

    Ranjkesh, Bahram; Chevallier, Jacques; Salehi, Hamideh; Cuisinier, Frédéric; Isidor, Flemming; Løvschall, Henrik

    2016-01-01

    Abstract Aim: Calcium silicate cements are widely used in endodontics. Novel fast-setting calcium silicate cement with fluoride (Protooth) has been developed for potential applications in teeth crowns including cavity lining and cementation. Objective: To evaluate the surface apatite-forming ability of Protooth compositions as a function of fluoride content and immersion time in phosphate-buffered saline (PBS). Material and methods: Three cement compositions were tested: Protooth (3.5% fluoride and 10% radiocontrast), ultrafast Protooth (3.5% fluoride and 20% radiocontrast), and high fluoride Protooth (15% fluoride and 25% radiocontrast). Powders were cap-mixed with liquid, filled to the molds and immersed in PBS. Scanning electron microscopy, energy dispersive X-ray analysis, and Raman spectroscopy were used to characterize the precipitations morphology and composition after 1, 7, 28, and 56 days. Apatite/belite Raman peak height indicated the apatite thickness. Results: Spherical calcium phosphate precipitations with acicular crystallites were formed after 1-day immersion in PBS and Raman spectra disclosed the phosphate band at 965 cm−1, supporting the apatite formation over Protooth compositions. The apatite deposition continued and more voluminous precipitations were observed after 56 days over the surface of all cements. Raman bands suggested the formation of β-type carbonated apatite over Protooth compositions. High fluoride Protooth showed the most compact deposition with significantly higher apatite/belite ratio compared to Protooth and ultrafast Protooth after 28 and 56 days. Conclusions: Calcium phosphate precipitations (apatite) were formed over Protooth compositions after immersion in PBS with increasing apatite formation as a function of time. High fluoride Protooth exhibited thicker apatite deposition. PMID:27335901

  14. Endogenous Lunar Volatiles: Insights into the Abundances of Volatiles in the Moon from Lunar Apatite

    NASA Technical Reports Server (NTRS)

    McCubbin, Francis

    2016-01-01

    At the time of publication of New Views of the Moon, it was thought that the Moon was bone dry with less than about 1 ppb H2O. However in 2007, initial reports at the 38th Lunar and Planetary Science Conference speculated that H-species were present in both apatites and pyroclastic volcanic lunar glasses. These early reports were later confirmed through peer-review, which motivated many subsequent studies on magmatic volatiles in and on the Moon within the last decade. Some of these studies have cast into question the post-Apollo view of lunar formation, the distribution and sources of volatiles in the Earth-Moon system, and the thermal and magmatic evolution of the Moon. The mineral apatite has been one of the pillars of this new field of study, and it will be the primary focus of this abstract. Although apatite has been used both to understand the abundances of volatiles in lunar systems as well as the isotopic compositions of those volatiles, the focus here will be on the abundances of F, Cl, and H2O. This work demonstrates the utility of apatite in advancing our understanding of lunar volatiles, hence apatite should be among the topics covered in the endogenous lunar volatile chapter in NVM II. Truncated ternary plot of apatite X-site occupancy (mol%) from highlands apatite and mare basalt apatite plotted on the relative volatile abundance diagram from. The solid black lines delineate fields of relative abundances of F, Cl, and H2O (on a weight basis) in the melt from which the apatite crystallized. The diagram was constructed using available apatite/melt partitioning data for fluorine, chlorine, and hydroxyl.

  15. Effects of the method of apatite seed crystals addition on setting reaction of α-tricalcium phosphate based apatite cement.

    PubMed

    Tsuru, Kanji; Ruslin; Maruta, Michito; Matsuya, Shigeki; Ishikawa, Kunio

    2015-10-01

    Appropriate setting time is an important parameter that determines the effectiveness of apatite cement (AC) for clinical application, given the issues of crystalline inflammatory response phenomena if AC fails to set. To this end, the present study analyzes the effects of the method of apatite seed crystals addition on the setting reaction of α-tricalcium phosphate (α-TCP) based AC. Two ACs, both consisting of α-TCP and calcium deficient hydroxyapatite (cdHAp), were analyzed in this study. In one AC, cdHAp was added externally to α-TCP and this AC was abbreviated as AC(EA). In the other AC, α-TCP was partially hydrolyzed to form cdHAp on the surface of α-TCP. This AC was referred to as AC(PH). Results indicate a decrease in the setting time of both ACs with the addition of cdHAp. Among them, for the given amount of added cdHAp, AC(PH) showed relatively shorter setting time than AC(EA). Besides, the mechanical strength of the set AC(PH) was also higher than that of set AC(EA). These properties of AC(PH) were attributed to the predominant crystal growth of cdHAp in the vicinity of the α-TCP particle surface. Accordingly, it can be concluded that the partial hydrolysis of α-TCP may be a better approach to add low crystalline cdHAp onto α-TCP based AC.

  16. Distribution of halogens between fluid and apatite during fluid-mediated replacement processes

    NASA Astrophysics Data System (ADS)

    Kusebauch, Christof; John, Timm; Whitehouse, Martin J.; Klemme, Stephan; Putnis, Andrew

    2015-12-01

    Apatite (Ca5(PO4)3(OH, F, Cl)) is one of the main host of halogens in magmatic and metamorphic rocks and plays a unique role during fluid-rock interaction as it incorporates halogens (i.e. F, Cl, Br, I) and OH from hydrothermal fluids to form a ternary solid solution of the endmembers F-apatite, Cl-apatite and OH-apatite. Here, we present an experimental study to investigate the processes during interaction of Cl-apatite with different aqueous solutions (KOH, NaCl, NaF of different concentration also doped with NaBr, NaI) at crustal conditions (400-700 °C and 0.2 GPa) leading to the formation of new apatite. We use the experimental results to calculate partition coefficients of halogens between apatite and fluid. Due to a coupled dissolution-reprecipitation mechanism new apatite is always formed as a pseudomorphic replacement of Cl-apatite. Additionally, some experiments produce new apatite also as an epitaxial overgrowth. The composition of new apatite is mainly governed by complex characteristics of the fluid phase from which it is precipitating and depends on composition of the fluid, temperature and fluid to mineral ratio. Furthermore, replaced apatite shows a compositional zonation, which is attributed to a compositional evolution of the coexisting fluid in local equilibrium with the newly formed apatite. Apatite/fluid partition coefficients for F depend on the concentration of F in the fluid and increase from 75 at high concentrations (460 μg/g F) to 300 at low concentrations (46 μg/g F) indicating a high compatibility of F in apatite. A correlation of Cl-concentration in apatite with Cl- concentration of fluid is not observed for experiments with highly saline solutions, composition of new apatite is rather governed by OH- concentration of the hydrothermal fluid. Low partition coefficients were measured for the larger halogens Br and I and vary between 0.7 * 10-3-152 * 10-3 for Br and 0.3 * 10-3-17 * 10-3 for I, respectively. Br seems to have D values of

  17. SUPERFUND TREATABILITY CLEARINGHOUSE: FINAL REPORT: DEVELOPMENT OF OPTIMUM TREATMENT SYSTEM FOR WASTEWATER LAGOONS PHASE II - SOLVENT EXTRACTION LABORATORY TESTING

    EPA Science Inventory

    The U.S. Army surveyed innovative treatment techniques for restoration of hazardous waste lagoons and selected solvent extraction as cost-effective restoration for further study. This treatability study focuses on treatment of organic (explosive) contaminated lagoon sediments w...

  18. Treatability studies on different refinery wastewater samples using high-throughput microbial electrolysis cells (MECs).

    PubMed

    Ren, Lijiao; Siegert, Michael; Ivanov, Ivan; Pisciotta, John M; Logan, Bruce E

    2013-05-01

    High-throughput microbial electrolysis cells (MECs) were used to perform treatability studies on many different refinery wastewater samples all having appreciably different characteristics, which resulted in large differences in current generation. A de-oiled refinery wastewater sample from one site (DOW1) produced the best results, with 2.1±0.2 A/m(2) (maximum current density), 79% chemical oxygen demand removal, and 82% headspace biological oxygen demand removal. These results were similar to those obtained using domestic wastewater. Two other de-oiled refinery wastewater samples also showed good performance, with a de-oiled oily sewer sample producing less current. A stabilization lagoon sample and a stripped sour wastewater sample failed to produce appreciable current. Electricity production, organics removal, and startup time were improved when the anode was first acclimated to domestic wastewater. These results show mini-MECs are an effective method for evaluating treatability of different wastewaters.

  19. Long-term anaerobic treatability studies on opium alkaloids industry effluents.

    PubMed

    Aydin, Ali F; Ersahin, Mustafa E; Dereli, Recep K; Sarikaya, Hasan Z; Ozturk, Izzet

    2010-01-01

    In this study, the anaerobic treatability of high strength opium alkaloids processing industry wastewaters was investigated. The wastewater was fed to a lab-scale anaerobic upflow sludge blanket reactor (UASBR) operating at mesophilic conditions. The UASB reactor (11.5 L) was operated for 825 days at different hydraulic retention times ranging from 0.85 to 1.62 days and at organic loading rates ranging from 3.40 to 12.25 kg COD/m(3).day. Anaerobic treatability studies indicated that 300 L CH(4) can be produced per kg COD removed. At the 445th day of the study an extreme irreversible inhibition caused by N,N-dimethylaniline was experienced. This paper demonstrated that opium alkaloid industry wastewater can be efficiently treated by UASB type reactors with more than 80% COD removal efficiency at high organic loading rates.

  20. Treatability tests on water from a low-level waste burial ground

    SciTech Connect

    Taylor, P.A.

    1990-01-01

    Lab-scale treatability tests on trench water from a low-level waste burial ground have shown that the water can be successfully treated by existing wastewater treatment plants at Oak Ridge National Laboratory. Water from the four most highly contaminated trenches that had been identified to date was used in the treatability tests. The softening and ion exchange processes used in the Process Wastewater Treatment Plant removed Sr-90 from the trench water, which was the only radionuclide present at above the discharge limits. The air stripping and activated carbon adsorption processes used in the Nonradiological Wastewater Treatment Plant removed volatile and semi-volatile organics, which were the main contaminants in the trench water, to below detection limits. 6 refs., 2 figs., 7 tabs.

  1. Metallurgical Laboratory Treatability Study: An Analysis of Passive Soil Vapor Extraction Wells - June 2000 Update

    SciTech Connect

    Riha, B.D.

    2001-01-29

    The passive soil vapor extraction (PSVE) system at the MetLab of the Savannah River Site has been operating since May 1998. The results to date on the treatability study indicate the technology is performing well. Well concentrations are decreasing and contour maps of the vadose zone soil gas plume show a decrease in the extent of the plume. In the 2 years of operation approximately 270 pounds of chlorinated organic contaminants have been removed by natural barometric pumping of wells fitted with BaroBall valves (low pressure check valves). The PSVE system is performing well in a cost-effective manner. It is recommended that this system be allowed to continue operating to complete the remediation and to continue monitoring activities to verify and monitor the anticipated contaminant removal rates. The treatability study should be considered successfully completed and the remediation should be considered in full operation.

  2. 300-FF-1 operable unit remedial investigation phase II report: Physical separation of soils treatability study

    SciTech Connect

    Not Available

    1994-04-01

    This report describes the approach and results of physical separations treatability tests conducted at the Hanford Site in the North Process Pond of the 300-FF-1 Operable Unit. Physical separation of soils was identified as a remediation alternative due to the potential to significantly reduce the amount of contaminated soils prior to disposal. Tests were conducted using a system developed at Hanford consisting of modified EPA equipment integrated with screens, hoppers, conveyors, tanks, and pumps from the Hanford Site. The treatability tests discussed in this report consisted of four parts, in which an estimated 84 tons of soil was processed: (1) a pre-test run to set up the system and adjust system parameters for soils to be processed; (2) a baseline run to establish the performance of the system - Test No. 1; (3) a final run in which the system was modified as a result of findings from the baseline run - Test No. 2; and (4) water treatment.

  3. Treatable bacterial infections are underrecognized causes of fever in Ethiopian children.

    PubMed

    Aarsland, Sara J; Castellanos-Gonzalez, Alejandro; Lockamy, Kameron P; Mulu-Droppers, Ruth; Mulu, Moges; White, A Clinton; Cabada, Miguel M

    2012-07-01

    Febrile illnesses remain a major cause of morbidity and mortality in resource-poor countries, but too often, tests are not available to determine the causes, leading to misdiagnosis and inappropriate treatment. To determine the cause of febrile illnesses, we recovered the malaria smears from 102 children presenting with fever to Soddo Christian Hospital in Wolaitta Soddo, Ethiopia. DNA was isolated from the smears and evaluated by real-time polymerase chain reaction. We identified pathogen DNA with probes for Plasmodium spp., Streptococcus pneumoniae, Rickettsia spp., Salmonella spp., and Borrelia spp. Overall, we showed that it is possible to isolate high-quality DNA and identify treatable pathogens from malaria blood smears. Furthermore, our data showed that bacterial pathogens (especially Pneumococcus, Rickettsia spp., and Borrelia spp.) are common and frequently unrecognized but treatable causes of febrile illnesses in Ethiopian children.

  4. Calcium Solubility In Zeolite Synthetic-Apatite Mixtures

    NASA Technical Reports Server (NTRS)

    Beiersdorfer, R.; Ming, D. W.

    1999-01-01

    Life support systems at a lunar or martian outpost will require the ability to produce food growing in 1) treated lunar or martian regolith; 2) a synthetic soil, or 3) some combination of both. Zeoponic soil, composed of NH4 (-) and K-exchanged clinoptilolite (Cp) and synthetic apatite (Ap), can provide slow-release fertilization via dissolution and ion-exchange. Equilibrium studies indicate that KNH4, P, and Mg are available to plants at sufficient levels, however, Ca is deficient. Ca availability can be increased by adding a second Ca-bearing mineral: calcite (Cal); dolomite (Dol); or wollastonite (Wol). Additions of Cal, Dol, and Wol systematically change the concentrations of Ca and P in solution. Cal has the greatest effect, Dol the least, and Wol is intermediate.

  5. Cortical bone screw fixation in ionically modified apatite cements.

    PubMed

    Barralet, J E; Duncan, C O; Dover, M S; Bassett, D C; Nishikawa, H; Monaghan, A; Gbureck, U

    2005-05-01

    Hydroxyapatite cements are used in reconstruction of the face; usually in well-defined cavities where the cement can be stabilized without the need for internal fixation. A hydroxyapatite cement that could enable screw fixation and some loading therefore has considerable potential in maxillofacial reconstruction. It has been demonstrated recently that water demand of calcium phosphate cements can be reduced by ionically modifying the liquid component. This study investigated the capacity of an ionically modified precompacted apatite cement to retain self-tapping cortical bone screws. Screw pullout forces were determined in the direction of the screw long axis and perpendicular to it, using cortical bone and polymethylmethacrylate cement as a control. In bending pullout tests, measured forces to remove screws from ionically modified precompacted cement were insignificantly different from cortical bone. However, pullout forces of bone screws from hydroxyapatite cement decreased with aging time in vitro.

  6. Magnetic apatite for structural insights on the plasma membrane.

    PubMed

    Stanca, Sarmiza E; Müller, Robert; Dellith, Jan; Nietzsche, Sandor; Stöckel, Stephan; Biskup, Christoph; Deckert, Volker; Krafft, Christoph; Popp, Jürgen; Fritzsche, Wolfgang

    2015-01-21

    The iron oxide-hydroxyapatite (FeOxHA) nanoparticles reported here differ from those reported before by their advantage of homogeneity and simple preparation; moreover, the presence of carboxymethyldextran (CMD), together with hydroxyapatite (HA), allows access to the cellular membrane, which makes our magnetic apatite unique. These nanoparticles combine magnetic behavior, Raman label ability and the property of interaction with the cellular membrane; they therefore represent an interesting material for structural differentiation of the cell membrane. It was observed by Raman spectroscopy, scanning electron microscopy (SEM) and fluorescence microscopy that FeOxHA adheres to the plasma membrane and does not penetrate the membrane. These insights make the nanoparticles a promising material for magnetic cell sorting, e.g. in microfluidic device applications.

  7. Apatite mineralization in teeth of the chiton Acanthopleura echinata.

    PubMed

    Lee, A P; Brooker, L R; Macey, D J; van Bronswijk, W; Webb, J

    2000-11-01

    Raman spectroscopy has been used to demonstrate, for the first time, that calcium mineralization in the core of the major lateral teeth of the chiton Acanthopleura echinata takes place as an ordered process, with crystalline carbonated apatite being the first mineral deposited. Deposition begins at the top of the tooth core, under the so-called tab region, progresses down the interior surface of the tab and lepidocrocite layer, and then extends outwards to the anterior surface. Mineralization is not initiated until the lepidocrocite layer has isolated the core of the tooth from the magnetite cap. The last region to be infiltrated is the anterior basal region of the tooth cusp, immediately above the junction zone. The junction zone is also a region of high ion density, as determined by energy dispersive spectroscopy (EDS) analysis, but we show here for the first time that it is free of mineral deposits, acting instead as a transfer and storage region.

  8. Biomimetic whisker-shaped apatite coating of titanium powder.

    PubMed

    Sim, Young Uk; Kim, Jong Hee; Yang, Tae Young; Yoon, Seog Young; Park, Hong Chae

    2010-05-01

    Biomimetic apatite coatings on chemically modified titanium powder have been processed and the resulting coating layers evaluated in terms of morphology, composition and structure, using TF-XRD, XPS, SEM, TEM and FTIR analysis. After 7 days immersion in a simulated body fluid (SBF), nanometer-sized fine precipitates with an amorphous whisker-like phase and a Ca/P atomic ratio of 1.94 were obtained on the external surface of the titanium particles. When the immersion time in SBF was extended to 16 days, the coating layer consisted of the whisker-like nanostructured crystals of carbonated hydroxyapatite with a atomic ratio of 3; in such a case, a double coating layer was developed. The double layer could be divided into two regions and could be clearly distinguished: an inner dense region (approximately 200 nm in thickness) which may include hard agglomerated crystals and an outer less dense region (> 500 nm in thickness) in which crystals are loosely distributed.

  9. Magnetic apatite for structural insights on the plasma membrane

    NASA Astrophysics Data System (ADS)

    Stanca, Sarmiza E.; Müller, Robert; Dellith, Jan; Nietzsche, Sandor; Stöckel, Stephan; Biskup, Christoph; Deckert, Volker; Krafft, Christoph; Popp, Jürgen; Fritzsche, Wolfgang

    2015-01-01

    The iron oxide-hydroxyapatite (FeOxHA) nanoparticles reported here differ from those reported before by their advantage of homogeneity and simple preparation; moreover, the presence of carboxymethyldextran (CMD), together with hydroxyapatite (HA), allows access to the cellular membrane, which makes our magnetic apatite unique. These nanoparticles combine magnetic behavior, Raman label ability and the property of interaction with the cellular membrane; they therefore represent an interesting material for structural differentiation of the cell membrane. It was observed by Raman spectroscopy, scanning electron microscopy (SEM) and fluorescence microscopy that FeOxHA adheres to the plasma membrane and does not penetrate the membrane. These insights make the nanoparticles a promising material for magnetic cell sorting, e.g. in microfluidic device applications.

  10. Effect of naturally occurring apatites on growth and morphology of algae.

    PubMed

    Smith, E A; Mayfield, C I; Wong, P T; Silverberg, B A

    1977-09-01

    Crystals (30--100 micrometer) of selected naturally occurring apatite (Ca10 (PO4)6(OH, F)2) samples were added to P-free (less than 0.001 microgram/ml total P) Bristol's medium (1-1000 microgram/ml of apatite) as the sole source of ortho-PO43-. The media were inoculated with washed, non-axenic cells of three chlorophycean algal species cultivated under PO43--deficient conditions. Phase-contrast and scanning electron microscopy revealed that at low slurry densities (1-10 microgram/ml of apatite), Ankistrodesmus braunii (ATCC 2744) cells were morphologically distorted. At concentrations of 100 and 1000 microgram/ml of apatite, more than 85% of the cells had undergone autospore formation within 7--10 days of incubation at 20 degrees C. Most autospores formed failed to germinate under high nutrient conditions. Scenedesmus longus (No. 1236) formed colonies when cultivated in Bristol's medium but daughter cells displayed a Chodatella-like unicellular morphology when grown in apatite media. Test algal species (Chlamydomonas dysosmos, S. longus, A. braunii) showed a marked preference for growth on apatite crystals over non-nutritive surfaces. Unialgal and mixed-algal cultures produced an extensive matrix of extracellular fibrous material in response to growth on crystals at concentrations greater than 10 microgram/ml of apatite. PMID:907915

  11. Single-crystal apatite nanowires sheathed in graphitic shells: synthesis, characterization, and application.

    PubMed

    Jeong, Namjo; Cha, Misun; Park, Yun Chang; Lee, Kyung Mee; Lee, Jae Hyup; Park, Byong Chon; Lee, Junghoon

    2013-07-23

    Vertically aligned one-dimensional hybrid structures, which are composed of apatite and graphitic structures, can be beneficial for orthopedic applications. However, they are difficult to generate using the current method. Here, we report the first synthesis of a single-crystal apatite nanowire encapsulated in graphitic shells by a one-step chemical vapor deposition. Incipient nucleation of apatite and its subsequent transformation to an oriented crystal are directed by derived gaseous phosphorine. Longitudinal growth of the oriented apatite crystal is achieved by a vapor-solid growth mechanism, whereas lateral growth is suppressed by the graphitic layers formed through arrangement of the derived aromatic hydrocarbon molecules. We show that this unusual combination of the apatite crystal and the graphitic shells can lead to an excellent osteogenic differentiation and bony fusion through a programmed smart behavior. For instance, the graphitic shells are degraded after the initial cell growth promoted by the graphitic nanostructures, and the cells continue proliferation on the bare apatite nanowires. Furthermore, a bending experiment indicates that such core-shell nanowires exhibited a superior bending stiffness compared to single-crystal apatite nanowires without graphitic shells. The results suggest a new strategy and direction for bone grafting materials with a highly controllable morphology and material conditions that can best stimulate bone cell differentiation and growth. PMID:23755838

  12. Biomimetic apatite-based composite materials obtained by spark plasma sintering (SPS): physicochemical and mechanical characterizations.

    PubMed

    Brouillet, Fabien; Laurencin, Danielle; Grossin, David; Drouet, Christophe; Estournes, Claude; Chevallier, Geoffroy; Rey, Christian

    2015-08-01

    Nanocrystalline calcium phosphate apatites are biomimetic compounds analogous to bone mineral and are at the origin of the bioactivity of most biomaterials used as bone substitutes. Their unique surface reactivity originates from the presence of a hydrated layer containing labile ions (mostly divalent ones). So the setup of 3D biocompatible apatite-based bioceramics exhibiting a high reactivity requests the development of «low» temperature consolidation processes such as spark plasma sintering (SPS), in order to preserve the characteristics of the hydrated nanocrystals. However, mechanical performances may still need to be improved for such nanocrystalline apatite bioceramics, especially in view of load-bearing applications. The reinforcement by association with biopolymers represents an appealing approach, while preserving the advantageous biological properties of biomimetic apatites. Herein, we report the preparation of composites based on biomimetic apatite associated with various quantities of microcrystalline cellulose (MCC, 1-20 wt%), a natural fibrous polymer. The SPS-consolidated composites were analyzed from both physicochemical (X-ray diffraction, Fourier transform infrared, solid state NMR) and mechanical (Brazilian test) viewpoints. The preservation of the physicochemical characteristics of apatite and cellulose in the final material was observed. Mechanical properties of the composite materials were found to be directly related to the polymer/apatite ratios and a maximum crushing strength was reached for 10 wt% of MCC.

  13. Treatability of organic fractions derived from secondary effluent by reverse osmosis membrane.

    PubMed

    Hu, J Y; Ong, S L; Shan, J H; Kang, J B; Ng, W J

    2003-11-01

    Dissolved organic matters (DOMs) from two batches of secondary effluent collected from a local water reclamation plant were fractionated using column chromatographic method with non-ionic resins XAD-8, AG MP-50 and IRA-96. Seven isolated fractions were obtained from the fractionation study and these fractions were quantified using DOC, UV(254) and SUVA values. The fractionation study revealed that the secondary effluent samples comprised about 47.3-60.6% of hydrophobic and 39.4-52.7% of hydrophilic solutes. The treatability of each isolated fraction was investigated by subjecting each fraction to reverse osmosis (RO) treatment individually. It was noted that RO process could achieve high DOC rejections for acid and neutral fractions (ranging from 80% to 98% removal) probably due to the negative charge of RO membrane. The results obtained also indicated that hydrophobicity of DOMs is significant in determining treatability of organic species by RO process. The performance of RO in terms of DOC rejection of un-fractionated secondary effluent was also investigated to assess possible effects of interactions among organic fractions on their treatability by RO process. It was noted that DOC rejection associated with the un-fractionated secondary effluent was generally higher (ranging from 2% to 45%) than the corresponding rejection obtained from each individual fraction isolated from the secondary effluent. This finding suggested there is a beneficial interaction among the fractions that in turn has contributed towards a better overall DOC rejection performance by RO treatment.

  14. Experimental Plan: Uranium Stabilization Through Polyphosphate Injection 300 Area Uranium Plume Treatability Demonstration Project

    SciTech Connect

    Wellman, Dawn M.; Fruchter, Jonathan S.; Vermeul, Vince R.

    2006-09-20

    This Test Plan describes a laboratory-testing program to be performed at Pacific Northwest National Laboratory (PNNL) in support of the 300-FF-5 Feasibility Study (FS). The objective of the proposed treatability test is to evaluate the efficacy of using polyphosphate injections to treat uranium contaminated groundwater in situ. This study will be used to: (1) Develop implementation cost estimates; (2) Identify implementation challenges; and (3) Investigate the technology's ability to meet remedial objectives These activities will be conducted in parallel with a limited field investigation, which is currently underway to more accurately define the vertical extent of uranium in the vadose zone, and in the capillary fringe zone laterally throughout the plume. The treatability test will establish the viability of the method and, along with characterization data from the limited field investigation, will provide the means for determining how best to implement the technology in the field. By conducting the treatability work in parallel with the ongoing Limited Field Investigation, the resulting Feasibility Study (FS) will provide proven, site-specific information for evaluating polyphosphate addition and selecting a suitable remediation strategy for the uranium plume within the FS time frame at an overall cost savings.

  15. Operable Unit 7-13/14 in situ thermal desorption treatability study work plan

    SciTech Connect

    Shaw, P.; Nickelson, D.; Hyde, R.

    1999-05-01

    This Work Plan provides technical details for conducting a treatability study that will evaluate the application of in situ thermal desorption (ISTD) to landfill waste at the Subsurface Disposal Area (SDA) at the Idaho National Engineering and Environmental Laboratory (INEEL). ISTD is a form of thermally enhanced vapor vacuum extraction that heats contaminated soil and waste underground to raise its temperature and thereby vaporize and destroy most organics. An aboveground vapor vacuum collection and treatment system then destroys or absorbs the remaining organics and vents carbon dioxide and water to the atmosphere. The technology is a byproduct of an advanced oil-well thermal extraction program. The purpose of the ISTD treatability study is to fill performance-based data gaps relative to off-gas system performance, administrative feasibility, effects of the treatment on radioactive contaminants, worker safety during mobilization and demobilization, and effects of landfill type waste on the process (time to remediate, subsidence potential, underground fires, etc.). By performing this treatability study, uncertainties associated with ISTD as a selected remedy will be reduced, providing a better foundation of remedial recommendations and ultimate selection of remedial actions for the SDA.

  16. Treatability studies for polyethylene encapsulation of INEL low-level mixed wastes. Final report

    SciTech Connect

    Lageraaen, P.R.; Patel, B.R.; Kalb, P.D.; Adams, J.W.

    1995-10-01

    Treatability studies for polyethylene encapsulation of Idaho National Engineering Laboratory (INEL) low-level mixed wastes were conducted at Brookhaven National Laboratory. The treatability work, which included thermal screening and/or processibility testing, was performed on priority candidate wastes identified by INEL to determine the applicability of polyethylene encapsulation for the solidification and stabilization of these mixed wastes. The candidate wastes selected for this preliminary study were Eutectic Salts, Ion Exchange Resins, Activated Carbons, Freon Contaminated Rags, TAN TURCO Decon 4502, ICPP Sodium Bearing Liquid Waste, and HTRE-3 Acid Spill Clean-up. Thermal screening was conducted for some of these wastes to determine the thermal stability of the wastes under expected pretreatment and processing conditions. Processibility testing to determine whether the wastes were amenable to extrusion processing included monitoring feed consistency, extruder output consistency, waste production homogeneity, and waste form performance. Processing parameters were not optimized within the scope of this study. However, based on the treatability results, polyethylene encapsulation does appear applicable as a primary or secondary treatment for most of these wastes.

  17. TREATABILITY TEST PLAN FOR DEEP VADOSE ZONE REMEDIATION AT THE HANFORD SITE CENTRAL PLATEAU

    SciTech Connect

    PETERSEN SW; MORSE JG; TRUEX MJ; LAST GV

    2007-11-29

    A treatability test plan has been prepared to address options for remediating portions of the deep vadose zone beneath a portion of the U.S. Department of Energy's (DOE's) Hanford Site. The vadose zone is the region of the subsurface that extends from the ground surface to the water table. The overriding objective of the treatability test plan is to recommend specific remediation technologies and laboratory and field tests to support the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 and Resource Conservation and Recovery Act of 1976 remedial decision-making process in the Central Plateau of the Hanford Site. Most of the technologies considered involve removing water from the vadose zone or immobilizing the contaminants to reduce the risk of contaminating groundwater. A multi-element approach to initial treatability testing is recommended, with the goal of providing the information needed to evaluate candidate technologies. The proposed tests focus on mitigating two contaminants--uranium and technetium. Specific technologies are recommended for testing at areas that may affect groundwater in the future, but a strategy to test other technologies is also presented.

  18. Adsorption of nucleotides on biomimetic apatite: The case of adenosine 5‧ monophosphate (AMP)

    NASA Astrophysics Data System (ADS)

    Hammami, K.; Feki, H. El; Marsan, O.; Drouet, C.

    2015-10-01

    This work investigates the interaction between the nucleotide adenosine 5‧ monophosphate molecule (AMP) and a biomimetic nanocrystalline carbonated apatite as a model for bone mineral. The analogy of the apatite phase used in this work with biological apatite was first pointed out by complementary techniques. AMP adsorption isotherms were then investigated. Obtained data were fitted to a Sips isotherm with an exponent greater than one suggesting positive cooperativity among adsorbed molecules. The data were compared to a previous study relative to the adsorption of another nucleotide, cytidine monophosphate (CMP) onto a similar substrate, evidencing some effect of the chemical nature of the nucleic base. An enhanced adsorption was observed under acidic (pH 6) conditions as opposed to pH 7.4, which parallels the case of DNA adsorption on biomimetic apatite. An estimated standard Gibbs free energy associated to the adsorption process (ΔG°ads ≅ -22 kJ/mol) intermediate between "physisorption" and "chemisorption" was found. The analysis of the solids after adsorption pointed to the preservation of the main characteristics of the apatite substrate but shifts or enhancements of Raman bands attributed to AMP showed the existence of chemical interactions involving both the phosphate and adenine parts of AMP. This contribution adds to the works conducted in view of better understanding the interaction of DNA/RNA and their constitutive nucleotides and the surface of biomimetic apatites. It could prove helpful in disciplines such as bone diagenesis (DNA/apatite interface in aged bones) or nanomedicine (setup of DNA- or RNA-loaded apatite systems). Also, the adsorption of nucleic acids on minerals like apatites could have played a role in the preservation of such biomolecules in the varying conditions known to exist at the origin of life on Earth, underlining the importance of dedicated adsorption studies.

  19. Biomimetic magnesium-carbonate-apatite nanocrystals endowed with strontium ions as anti-osteoporotic trigger.

    PubMed

    Iafisco, Michele; Ruffini, Andrea; Adamiano, Alessio; Sprio, Simone; Tampieri, Anna

    2014-02-01

    The present work investigates the preparation of biomimetic nanocrystalline apatites co-substituted with Mg, CO3 and Sr to be used as starting materials for the development of nanostructured bio-devices for regeneration of osteoporotic bone. Biological-like amounts of Mg and CO3 ions were inserted in the apatite structure to mimic the composition of bone apatite, whereas the addition of increasing quantities of Sr ions, from 0 up to 12 wt.%, as anti-osteoporotic agent, was evaluated. The chemical-physical features, the morphology, the degradation rates, the ion release kinetics as well as the in vitro bioactivity of the as-prepared apatites were fully evaluated. The results indicated that the incorporation of 12 wt.% of Sr can be viewed as a threshold for the structural stability of Mg-CO3-apatite. Indeed, incorporation of lower quantity of Sr did not induce considerable variations in the chemical structure of Mg-CO3-apatite, while when the Sr doping extent reached 12 wt.%, a dramatically destabilizing effect was detected on the crystal structure thus yielding alteration of the symmetry and distortion of the PO4. As a consequence, this apatite exhibited the fastest degradation kinetic and the highest amount of Sr ions released when tested in physiological conditions. In this respect, the surface crystallization of new calcium phosphate phase when immersed in physiological-like solution occurred by different mechanisms and extents due to the different structural chemistry of the variously doped apatites. Nevertheless, all the apatites synthesized in this work exhibited in vitro bioactivity demonstrating their potential use to develop biomedical devices with anti-osteoporotic functionality. PMID:24411371

  20. Remediation of copper contaminated soil by using different particle sizes of apatite: a field experiment.

    PubMed

    Xing, Jinfeng; Hu, Tiantian; Cang, Long; Zhou, Dongmei

    2016-01-01

    The particle size of apatite is one of the critical factors that influence the adsorption of heavy metals on apatite in the remediation of heavy metal contaminated soils using apatite. However, little research has been done evaluating the impact of different particle sizes of apatite on immobilization remediation of heavy metal polluted soils in field. In this study, the adsorption isothermal experiments of copper on three kinds of apatite was tested, and the field experiment by using different particle sizes apatite [nano-hydroxyapatite (NAP), micro-hydroxyapatite (MAP), ordinary particle apatite (OAP)] at a same dosage of 25.8 t/ha (1.16 %, W/W) was also conducted. Ryegrass was chosen as the test plant. The ryegrass biomass, the copper contents in ryegrass and the copper fractionations in soil were determined after field experiments. Results of adsorption experiments showed that the adsorption amounts of copper on OAP was the lowest among different particles. The adsorption amounts of copper on MAP was higher than NAP at high copper equilibrium concentration (>1 mmol L(-1)), an opposite trend was obtained at low copper concentration (<1 mmol L(-1)). In the field experiment, we found that the application of different apatites could effectively increase the soil pH, decrease the available copper concentration in soil, provide more nutrient phosphate and promote the growth of ryegrass. The ryegrass biomass and the copper accumulation in ryegrass were the highest in MAP among all treatments. The effective order of apatite in phytoremediation of copper contaminated field soil was MAP > NAP > OAP, which was attributed to the high adsorption capacity of copper and the strong releasing of phosphate by MAP. PMID:27512641

  1. Exploiting radiation damage control on apatite (U Th)/He dates in cratonic regions

    NASA Astrophysics Data System (ADS)

    Flowers, Rebecca M.

    2009-01-01

    Apatites from four pairs of samples of Precambrian basement from the western Canadian shield were analyzed by (U-Th)/He thermochronometry to test for the influence of radiation damage on apatite (U-Th)/He dates in this cratonic region. Recent studies have demonstrated that the accumulation of radiation damage increases the apatite He retentivity, so that apatites with a span of effective U concentrations, eU, that experienced the same thermal history may be characterized by a range of closure temperatures. In this investigation, each sample pair consisted of a mafic dike cross-cutting felsic gneisses from a single outcrop or nearby outcrops that contained apatites with a span of eU. The apatites yielded (U-Th)/He dates from 846 to 123 Ma, and were positively correlated with eU within each sample pair. These results can be explained using a model that tracks the evolution of He mobility in response to the accumulation of radiation damage. When coupled with regional geological constraints, the data appear to require partial to complete He loss due to burial and reheating in Phanerozoic time. New apatite fission- track dates and length data were obtained for five of these samples. The apatite fission- track dates are Proterozoic regardless of apatite eU. Thermal history simulations indicate that the apatite fission-track data are compatible with the (U-Th)/He results, although the thermal histories are not identical in detail and the fission-track results alone do not require Phanerozoic heating. Together the data are consistent with burial of this region by ≥ 1 km of Phanerozoic strata that were subsequently denuded, thus pointing toward significant Phanerozoic deposition in the North American cratonic interior hundreds of kilometers east of where previously documented. The results suggest that exploiting radiation damage control on apatite (U-Th)/He dates through investigation of surface sample apatites with a span of closure temperatures can impose tighter

  2. Quantification of octacalcium phosphate, authigenic apatite and detrital apatite in coastal sediments using differential dissolution and standard addition

    NASA Astrophysics Data System (ADS)

    Oxmann, J. F.; Schwendenmann, L.

    2014-01-01

    Knowledge of calcium phosphate (Ca-P) solubility is crucial for understanding temporal and spatial variations of phosphorus (P) concentrations in water bodies and sedimentary reservoirs. In-situ relationships between liquid and solid-phase levels cannot be fully explained by dissolved analytes alone and need to be verified by determination of particular sediment P species. Lack of quantification methods for these species limits the knowledge of the P cycle. To address this issue, we (i) optimized a specifically developed conversion-extraction (CONVEX) method for P species quantification using standard additions; and (ii) simultaneously determined solubilities of Ca-P standards by measuring their pH-dependent contents in the sediment matrix. Ca-P minerals including various carbonate fluorapatite (CFAP) specimens from different localities, fluorapatite (FAP), fish bone apatite, synthetic hydroxylapatite (HAP) and octacalcium phosphate (OCP) were characterized by XRD, Raman, FTIR and elemental analysis. Sediment samples were incubated with and without these reference minerals and then sequentially extracted to quantify Ca-P species by their differential dissolution at pH values between 3 and 8. The quantification of solid-phase phosphates at varying pH revealed solubilities in the following order: OCP > HAP > CFAP (4.5% CO3) > CFAP (3.4% CO3) > CFAP (2.2% CO3) > FAP. Thus, CFAP was less soluble in sediment than HAP, and CFAP solubility increased with carbonate content. Unspiked sediment analyses together with standard addition analyses indicated consistent differential dissolution of natural sediment species vs. added reference species and therefore verified the applicability of the CONVEX method in separately determining the most prevalent Ca-P minerals. We found surprisingly high OCP contents in the analyzed coastal sediments which supports the hypothesis of apatite formation by an OCP precursor.

  3. Quantification of octacalcium phosphate, authigenic apatite and detrital apatite in coastal sediments using differential dissolution and standard addition

    NASA Astrophysics Data System (ADS)

    Oxmann, J. F.; Schwendenmann, L.

    2014-06-01

    Knowledge of calcium phosphate (Ca-P) solubility is crucial for understanding temporal and spatial variations of phosphorus (P) concentrations in water bodies and sedimentary reservoirs. In situ relationships between liquid- and solid-phase levels cannot be fully explained by dissolved analytes alone and need to be verified by determining particular sediment P species. Lack of quantification methods for these species limits the knowledge of the P cycle. To address this issue, we (i) optimized a specifically developed conversion-extraction (CONVEX) method for P species quantification using standard additions, and (ii) simultaneously determined solubilities of Ca-P standards by measuring their pH-dependent contents in the sediment matrix. Ca-P minerals including various carbonate fluorapatite (CFAP) specimens from different localities, fluorapatite (FAP), fish bone apatite, synthetic hydroxylapatite (HAP) and octacalcium phosphate (OCP) were characterized by XRD, Raman, FTIR and elemental analysis. Sediment samples were incubated with and without these reference minerals and then sequentially extracted to quantify Ca-P species by their differential dissolution at pH values between 3 and 8. The quantification of solid-phase phosphates at varying pH revealed solubilities in the following order: OCP > HAP > CFAP (4.5% CO3) > CFAP (3.4% CO3) > CFAP (2.2% CO3) > FAP. Thus, CFAP was less soluble in sediment than HAP, and CFAP solubility increased with carbonate content. Unspiked sediment analyses together with standard addition analyses indicated consistent differential dissolution of natural sediment species vs. added reference species and therefore verified the applicability of the CONVEX method in separately determining the most prevalent Ca-P minerals. We found surprisingly high OCP contents in the coastal sediments analyzed, which supports the hypothesis of apatite formation by an OCP precursor mechanism.

  4. In Situ Formation of Calcium Apatite in Soil for Sequestering Contaminants in Soil and Groundwater

    SciTech Connect

    Moore, Robert; Szecsody, Jim; Thompson, Mike

    2015-10-20

    A new method for in situ formation of a calcium apatite permeable reactive barrier that is a groundbreaking technology for containing radioactive/heavy metal contaminants threatening groundwater supplies.

  5. Dissolution mechanism of calcium apatites in acids: A review of literature

    PubMed Central

    Dorozhkin, Sergey V

    2012-01-01

    Eight dissolution models of calcium apatites (both fluorapatite and hydroxyapatite) in acids were drawn from the published literature, analyzed and discussed. Major limitations and drawbacks of the models were conversed in details. The models were shown to deal with different aspects of apatite dissolution phenomenon and none of them was able to describe the dissolution process in general. Therefore, an attempt to combine the findings obtained by different researchers was performed which resulted in creation of the general description of apatite dissolution in acids. For this purpose, eight dissolution models were assumed to complement each other and provide the correct description of the specific aspects of apatite dissolution. The general description considers all possible dissolution stages involved and points out to some missing and unclear phenomena to be experimentally studied and verified in future. This creates a new methodological approach to investigate reaction mechanisms based on sets of affine data, obtained by various research groups under dissimilar experimental conditions. PMID:25237611

  6. U-Th-Pb Systematics in Zircon and Apatite from the Chicxulub Crater, Mexico

    NASA Astrophysics Data System (ADS)

    Kring, D. A.; Shaulis, B. J.; Schmieder, M.; Lapen, T. J.

    2016-08-01

    We probe the U-Th-Pb systematics in zircon and apatite to determine if post-impact hydrothermal activity produced discernible effects that are related to the duration, thermal evolution, and chemistry of the hydrothermal system.

  7. Preparation of low-crystalline apatite nanoparticles and their coating onto quartz substrates.

    PubMed

    Kawashita, Masakazu; Taninai, Koji; Li, Zhixia; Ishikawa, Kunio; Yoshida, Yasuhiro

    2012-06-01

    We prepared low-crystalline apatite nanoparticles and coated them onto a surface of a Au/Cr-plated quartz substrate by the electrophoretic deposition (EPD) method or by using a self-assembled monolayer of 11-mercaptoundecanoic acid (SAM method). Low-crystalline apatite nanoparticles around 10 nm in size with extremely low contents of undesirable residual products were obtained by adding (NH(4))(2)HPO(4) aqueous droplets into a modified synthetic body fluid solution that contained Ca(CH(3)COO)(2). The apatite nanoparticles were successfully coated by either the EPD method or the SAM method; the nanoparticle coating achieved by the SAM method was more uniform than that achieved by the EPD method. The present SAM method is expected to be a promising technique for obtaining a quartz substrate coated with apatite nanoparticles, which can be used as a quartz crystal microbalance device.

  8. Detoxification of a highly toxic lead-loaded industrial solid waste by stabilization using apatites.

    PubMed

    Ioannidis, T A; Zouboulis, A I

    2003-02-28

    Apatites are known for their properties to immobilize lead contained in aqueous solutions or contaminated soils. In this study, apatites were examined as stabilization additives for lead-loaded industrial solid toxic wastes. The specific waste was the residue, obtained after thermal treatment of sludges (incineration), which was derived from tetraethyl lead fuel storage tanks. It was found to contain around 30 wt.% lead and 33 wt.% iron. Standard leaching tests (according to DIN 38414 S-4) were applied for the determination of leachability of metals from the ash and, thus, of chemical toxicity; the proposed leaching tests examined both initial and stabilized products in order to evaluate the effectiveness of the applied additives. The results obtained demonstrate the fact that lead concentrations in leachates, after the application of the proposed leaching tests using apatites as additives and with a ratio of 50% solid waste-50 wt.% apatite, could be reduced to the range of 1mg/l.

  9. Geochemistry of Apatite in Climactic and Pre-Climactic Tephra from Mt. Mazama, Crater Lake, Oregon

    NASA Astrophysics Data System (ADS)

    Mandeville, C. W.; Langstaff, M.

    2007-12-01

    Apatite is a common accessory mineral in arc volcanic rocks that potentially records information about the dissolved volatile (S,Cl,F,OH) and trace-element concentrations (Sr, Ba, REEs) of the melt from which it crystallized. In a previous study of apatite from arc and convergent margin volcanic rocks, Peng et al. (1997) reported 0.63 wt.% SO3 in Mazama apatite grains with a corresponding SrO content of 0.18 wt.%, comprising some of the highest SO3 and SrO values in their data. Our electron microprobe study of apatite in climactic and pre-climactic Mazama tephra was done in order to assess possible correlation of apatite SO3 with Sr content of low-Sr and high-Sr recharge magmas identified based on whole-rock and matrix glass data (Bacon and Druitt, 1988) and Sr content of plagioclase (Druitt and Bacon 1989). Samples chosen represent all magmatic components erupted during the ca. 7700 year before present climactic eruption and precursor Llao Rock and Cleetwood eruptions. We compare the S, Cl, and F content of Mazama apatites with recent experimental data for S, Cl, and F partitioning between apatite and melt and with dissolved volatiles previously measured in melt inclusions from corresponding or similar Mazama samples. Our electron microprobe data confirm the presence of rare Mazama apatites with up to 0.78 wt.% SO3 and 0.12 wt.% SrO in Llao Rock, Cleetwood, and climactic scoria and pumice samples. However, high SO3 and SrO apatites are not restricted to high-Sr scoria hosts, but have been observed in low-Sr scoria, in Llao Rock rhyodacitic pumices and in Cleetwood rhyodacitic pumices, thus indicating significant magma mixing prior to the Llao Rock, Cleetwood and climactic eruptions. Most apatite SO3 and SrO data falls within the 0.06 to 0.36 wt.% and 0.04 to 0.12 wt.% range, respectively. Experimental data on SO3 partitioning between apatite and melt and maximum sulfur contents of 300 to 350 ppm measured in climactic and Cleetwood rhyodacitic melt inclusions

  10. Fluoride enhances transfection activity of carbonate apatite by increasing cytoplasmic stability of plasmid DNA

    SciTech Connect

    Chowdhury, E.H.

    2011-06-17

    Highlights: {yields} Cytoplasmic stability of plasmid DNA is enhanced by fluoride incorporation into carbonate apatite carrier. {yields} Fluoridated carbonate apatite promotes a robust increase in transgene expression. {yields} Controlled dissolution of fluoridated carbonate apatite in endosomal acidic environment might buffer the endosomes and prevent degradation of the released DNA. -- Abstract: Intracellular delivery of a functional gene or a nucleic acid sequence to specifically knockdown a harmful gene is a potential approach to precisely treat a critical human disease. The intensive efforts in the last few decades led to the development of a number of viral and non-viral synthetic vectors. However, an ideal delivery tool in terms of the safety and efficacy has yet to be established. Recently, we have developed pH-sensing inorganic nanocrystals of carbonate apatite for efficient and cell-targeted delivery of gene and gene-silencing RNA. Here we show that addition of very low level of fluoride to the particle-forming medium facilitates a robust increase in transgene expression following post-incubation of the particles with HeLa cells. Confocal microscopic observation and Southern blotting prove the cytoplasmic existence of plasmid DNA delivered by likely formed fluoridated carbonate apatite particles while degradation of plasmid DNA presumably by cytoplasmic nucleases was noticed following delivery with apatite particles alone. The beneficial role of fluoride in enhancing carbonate apatite-mediated gene expression might be due to the buffering potential of generated fluoridated apatite in endosomal acidic environment, thereby increasing the half-life of delivered plasmid DNA.

  11. Apatite formation on non-woven fabric of carboxymethylated chitin in SBF.

    PubMed

    Kokubo, Tadashi; Hanakawa, Masayuki; Kawashita, Masakazu; Minoda, Masahiko; Beppu, Toshiyuki; Miyamoto, Takeaki; Nakamura, Takashi

    2004-08-01

    Chitin fibres constituting a non-woven fabric were carboxymethylated in monochloro acetic acid and treated with saturated Ca(OH)(2) aqueous solution. Within 3 days in a simulated body fluid with pH value and ion concentrations nearly equal to those of human blood plasma, a bonelike apatite layer formed on the surface of fibres of the treated fabric. The apatite-chitin fibre composite thus prepared is expected to be useful as a flexible bioactive bone-repairing material.

  12. Uranium-lead ages of apatite from iron oxide ores of the Bafq District, East-Central Iran

    NASA Astrophysics Data System (ADS)

    Stosch, Heinz-Günter; Romer, Rolf L.; Daliran, Farahnaz; Rhede, Dieter

    2011-01-01

    Iron oxide-apatite (IOA) deposits, often referred to as Kiruna-type iron ore deposits, are known to have formed from the Proterozoic to the Tertiary. They are commonly associated with calc-alkaline volcanic rocks and regional- to deposit-scale metasomatic alteration. In the Bafq District in east Central Iran, economic iron oxide-apatite deposits occur within felsic volcanic tuffs and volcanosedimentary sequences of Early Cambrian age. In order to constrain the age of formation of these ores and their relationship with the Early Cambrian magmatic event, we have determined the U-Pb apatite age for five occurrences in the Bafq District. In a 206Pb/238U vs. 207Pb/235U diagram, apatite free of or poor in inclusions of other minerals plots along the Concordia between 539 and 527 Ma with four out of five samples from one deposit clustering at the upper end of this range. For this deposit, we interpret this cluster to represent the age of apatite formation, whereas the spread towards younger ages may reflect either minor Pb loss or several events of IOA formation. Apatite with inclusions of monazite (±xenotime) yields disturbed systems with inclusions having developed after formation of the iron ore-apatite deposits, possibly as late as 130-140 Ma ago. Obtained apatite ages confirms that (IOA) and the apatite-rich rocks (apatites) of the Bafq district formed coevally with the Early Cambrian magmatic (-metasomatic) events.

  13. The lanthanides and yttrium in minerals of the apatite group; a review

    USGS Publications Warehouse

    Fleischer, Michael; Altschuler, Z.S.

    1982-01-01

    More than 1000 analyses have been tabulated of the distribution of the lanthanides and yttrium in minerals of the apatite group, recalculated to atomic percentages. Average compositions have been calculated for apatites from 14 types of rocks. These show a progressive change of composition from apatites of granitic pegmatites, highest in the heavy lanthanides and yttrium, to those from alkalic pegmatites, highest in the light lanthanides and lowest in yttrium. This progression is clearly shown in plots of S (= at % La+Ce+Pr) vs the ratio La/Nd and of S vs the ratio 100Y/(Y+Ln), where Ln is the sum of the lanthanides. Apatites of sedimentary phosphorites occupy a special position, being relatively depleted in Ce and relatively enriched in yttrium and the heavy lanthanides, consequences of deposition from sea water. Apatites associated with iron ores are close in composition to apatites of carbonatites, alkalic ultramafic, and ultramafic rocks, being enriched in the light lanthanides and depleted in the heavy lanthanides. Their compositions do not support the hypothesis of Parak that the Kiruna-type ores are of sedimentary origin. Table 9 and Figures 1-3 show the dependence of lanthanide distribution on the nature of the host rock. Although a given analysis of the lanthanides does not unequivocally permit certain identification of the host rock, it can indicate a choice of highly probable host rocks.

  14. New insights into structural alteration of enamel apatite induced by citric acid and sodium fluoride solutions.

    PubMed

    Wang, Xiaojie; Klocke, Arndt; Mihailova, Boriana; Tosheva, Lubomira; Bismayer, Ulrich

    2008-07-24

    Attenuated total reflectance infrared spectroscopy and complementary scanning electron microscopy were applied to analyze the surface structure of enamel apatite exposed to citric acid and to investigate the protective potential of fluorine-containing reagents against citric acid-induced erosion. Enamel and, for comparison, geological hydroxylapatite samples were treated with aqueous solutions of citric acid and sodium fluoride of different concentrations, ranging from 0.01 to 0.5 mol/L for citric acid solutions and from 0.5 to 2.0% for fluoride solutions. The two solutions were applied either simultaneously or consecutively. The citric acid-induced structural modification of apatite increases with the increase in the citric acid concentration and the number of treatments. The application of sodium fluoride alone does not suppress the atomic level changes in apatite exposed to acidic agents. The addition of sodium fluoride to citric acid solutions leads to formation of surface CaF2 and considerably reduces the changes in the apatite P-O-Ca framework. However, the CaF2 globules deposited on the enamel surface seem to be insufficient to prevent the alteration of the apatite structure upon further exposure to acidic agents. No evidence for fluorine-induced recovery of the apatite structure was found.

  15. Combined apatite fission track and U-Pb dating by LA-ICPMS

    NASA Astrophysics Data System (ADS)

    Chew, D. M.; Donelick, R. A.

    2012-04-01

    Apatite is a common accessory mineral in igneous, metamorphic and clastic sedimentary rocks. It is a nearly ubiquitous accessory phase in igneous rocks, is common in metamorphic rocks of pelitic, carbonate, basaltic, and ultramafic composition and is virtually ubiquitous in clastic sedimentary rocks. In contrast to the polycyclic behavior of the stable heavy mineral zircon, apatite is unstable in acidic groundwaters and has limited mechanical stability in sedimentary transport systems. Apatite has many potential applications in provenance studies, particularly as it likely represents first-cycle detritus. Fission track and U-Pb dating are very powerful techniques in apatite provenance studies. They yield complementary information, with the apatite fission-track system yielding low-temperature exhumation ages and the U-Pb system yielding high-temperature cooling ages which constrain the timing of apatite crystallization. This study focuses on integrating apatite fission track and U-Pb dating by the LA-ICPMS method. Our approach is intentionally broad in scope, and is applicable to any quadrupole or rapid-scanning magnetic-sector LA-ICPMS system. Calculating uranium concentrations in fission-track dating by LA-ICPMS increases the speed of analysis and sample throughput compared to the conventional external detector method and avoids the need for neutron irradiation (Hasebe et al., 2004). LA-ICPMS-based uranium measurements in apatite are measured relative to an internal concentration standard (typically 43Ca). Ca in apatite is not always stochiometric as minor cations (Mn2+, Sr2+, Ba2+ and Fe2+) and REE can substitute with Ca2+. These substitutions must be quantified by multi-elemental LA-ICPMS analyses. Such data are also useful for discriminating between different apatite populations in sedimentary or volcaniclastic rocks based on their trace-element chemistry. Low U, Th and radiogenic Pb concentrations, elevated common Pb / radiogenic Pb ratios and U-Pb elemental

  16. Gene Delivery Potential of Biofunctional Carbonate Apatite Nanoparticles in Lungs

    PubMed Central

    Alhaji, Suleiman Yusuf; Chowdhury, Ezharul Houque; Rosli, Rozita

    2014-01-01

    Existing nonviral gene delivery systems to lungs are inefficient and associated with dose limiting toxicity in mammalian cells. Therefore, carbonate apatite (CO3Ap) nanoparticles were examined as an alternative strategy for effective gene delivery to the lungs. This study aimed to (1) assess the gene delivery efficiency of CO3Ap in vitro and in mouse lungs, (2) evaluate the cytotoxicity effect of CO3Ap/pDNA in vitro, and (3) characterize the CO3Ap/pDNA complex formulations. A significantly high level of reporter gene expression was detected from the lung cell line transfected with CO3Ap/pDNA complex prepared in both serum and serum-free medium. Cytotoxicity analysis revealed that the percentage of the viable cells treated with CO3Ap to be almost similar to the untreated cells. Characterization analyses showed that the CO3Ap/pDNA complexes are in a nanometer range with aggregated spherical structures and tended to be more negatively charged. In the lung of mice, highest level of transgene expression was observed when CO3Ap (8 μL) was complexed with 40 μg of pDNA at day 1 after administration. Although massive reduction of gene expression was seen beyond day 1 post administration, the level of expression remained significant throughout the study period. PMID:25143941

  17. Infrared spectra of carbonate apatites: v2-Region bands.

    PubMed

    Fleet, Michael E

    2009-03-01

    The proportions of A and B carbonate ions in a selection of AB carbonate apatites, including hydroxyapatite (CHAP), chlorapatite (CCLAP) and fluorapatite (CFAP), have been obtained using the out-of-plane bend (nu(2)) bands of Fourier transform infrared (FTIR) spectra. Band area ratios (B/A) are in very good agreement with site occupancies from single-crystal X-ray structure refinement; the correlation is linear (1:1) for B/A values ranging up to three. Most compositions have nu(2) spectra with one band for A carbonate (at 878-880 cm(-1)) and one for B (at 870-872 cm(-1)). Na-free AB CHAP has a third prominent band at 862 cm(-1), which is assigned to the stuffed channel species (A2), and Na-bearing CFAP has a third band at 864 cm(-1), which is assigned to a second B carbonate environment (B2). The A2 and B2 assignments are based largely on spectral changes in annealed samples.

  18. Demonstration testing and evaluation of in situ soil heating. Treatability study work plan, Revision 1

    SciTech Connect

    Sresty, G.C.

    1994-07-07

    A Treatability Study planned for the demonstration of the in situ electromagnetic (EM) heating process to remove organic solvents is described in this Work Plan. The treatability study will be conducted by heating subsurface vadose-zone soils in an organic plume adjacent to the Classified Burial Ground K-1070-D located at K-25 Site, Oak Ridge. The test is scheduled to start during the fourth quarter of FY94 and will be completed during the first quarter of FY95. The EM heating process for soil decontamination is based on volumetric heating technologies developed during the `70s for the recovery of fuels from shale and tar sands by IIT Research Institute (IITRI) under a co-operative program with the US Department of Energy (DOE). Additional modifications of the technology developed during the mid `80s are currently used for the production of heavy oil and waste treatment. Over the last nine years, a number of Government agencies (EPA, Army, AF, and DOE) and industries sponsored further development and testing of the in situ heating and soil decontamination process for the remediation of soils containing hazardous organic contaminants. In this process the soil is heated in situ using electrical energy. The contaminants are removed from the soil due to enhanced vaporization, steam distillation and stripping. IITRI will demonstrate the EM Process for in situ soil decontamination at K-25 Site under the proposed treatability study. Most of the contaminants of concern are volatile organics which can be removed by heating the soil to a temperature range of 85 to 95 C. The efficiency of the treatment will be determined by comparing the concentration of contaminants in soil samples. Samples will be obtained before and after the demonstration for a measurement of the concentration of contaminants of concern.

  19. Final waste forms project: Performance criteria for phase I treatability studies

    SciTech Connect

    Gilliam, T.M.; Hutchins, D.A.; Chodak, P. III

    1994-06-01

    This document defines the product performance criteria to be used in Phase I of the Final Waste Forms Project. In Phase I, treatability studies will be performed to provide {open_quotes}proof-of-principle{close_quotes} data to establish the viability of stabilization/solidification (S/S) technologies. This information is required by March 1995. In Phase II, further treatability studies, some at the pilot scale, will be performed to provide sufficient data to allow treatment alternatives identified in Phase I to be more fully developed and evaluated, as well as to reduce performance uncertainties for those methods chosen to treat a specific waste. Three main factors influence the development and selection of an optimum waste form formulation and hence affect selection of performance criteria. These factors are regulatory, process-specific, and site-specific waste form standards or requirements. Clearly, the optimum waste form formulation will require consideration of performance criteria constraints from each of the three categories. Phase I will focus only on the regulatory criteria. These criteria may be considered the minimum criteria for an acceptable waste form. In other words, a S/S technology is considered viable only if it meet applicable regulatory criteria. The criteria to be utilized in the Phase I treatability studies were primarily taken from Environmental Protection Agency regulations addressed in 40 CFR 260 through 265 and 268; and Nuclear Regulatory Commission regulations addressed in 10 CFR 61. Thus the majority of the identified criteria are independent of waste form matrix composition (i.e., applicable to cement, glass, organic binders etc.).

  20. Treatability of organic matter derived from surface and subsurface waters of drinking water catchments.

    PubMed

    Awad, John; van Leeuwen, John; Liffner, Joel; Chow, Christopher; Drikas, Mary

    2016-02-01

    The treatability of NOM present in runoff and subsurface waters from discrete zero-order catchments (ZOCs) with three land management practices (Australian native vegetation, pine plantation, grasslands) on varying soil textures of a closed drinking water reservoir-catchment was investigated. Subsurface water samples were collected by lysimeters and shallow piezometers and surface waters by installation of barriers that diverted waters to collection devices. For small sample volumes collected, a 'micro' jar testing procedure was developed to assess the treatability of organics by enhanced coagulation using alum, under standardised conditions. DOM present in water samples was quantified by measurement of DOC and UV absorbance (at 254 nm) and characterized using these and F-EEM. The mean alum dose rate (mg alum per mg DOC removed or Al/DOC) was found to be lower for DOM from sandy soil ZOCs (21.1 ± 11.0 Al/DOC) than from clayey soil ZOCs (38.6 ± 27.7 Al/DOC). ZOCs with Pinus radiata had prominent litter layers (6.3 ± 2.6 cm), and despite differences in soil textures showed similarity in DOM character in subsurface waters, and in alum dose rates (22.2 ± 5.5 Al/DOC). For sandy soil ZOCs, the lowest alum dose rates (16.5 ± 10.6 Al/DOC) were for waters from native vegetation catchment while, for clayey soil ZOCs, waters from pine vegetation had the lowest alum dose rates (23.0 ± 5.0 Al/DOC). Where ZOCs have a prominent O horizon, soil minerals had no apparent influence on the treatability of DOM. PMID:26461444

  1. Treatability of organic matter derived from surface and subsurface waters of drinking water catchments.

    PubMed

    Awad, John; van Leeuwen, John; Liffner, Joel; Chow, Christopher; Drikas, Mary

    2016-02-01

    The treatability of NOM present in runoff and subsurface waters from discrete zero-order catchments (ZOCs) with three land management practices (Australian native vegetation, pine plantation, grasslands) on varying soil textures of a closed drinking water reservoir-catchment was investigated. Subsurface water samples were collected by lysimeters and shallow piezometers and surface waters by installation of barriers that diverted waters to collection devices. For small sample volumes collected, a 'micro' jar testing procedure was developed to assess the treatability of organics by enhanced coagulation using alum, under standardised conditions. DOM present in water samples was quantified by measurement of DOC and UV absorbance (at 254 nm) and characterized using these and F-EEM. The mean alum dose rate (mg alum per mg DOC removed or Al/DOC) was found to be lower for DOM from sandy soil ZOCs (21.1 ± 11.0 Al/DOC) than from clayey soil ZOCs (38.6 ± 27.7 Al/DOC). ZOCs with Pinus radiata had prominent litter layers (6.3 ± 2.6 cm), and despite differences in soil textures showed similarity in DOM character in subsurface waters, and in alum dose rates (22.2 ± 5.5 Al/DOC). For sandy soil ZOCs, the lowest alum dose rates (16.5 ± 10.6 Al/DOC) were for waters from native vegetation catchment while, for clayey soil ZOCs, waters from pine vegetation had the lowest alum dose rates (23.0 ± 5.0 Al/DOC). Where ZOCs have a prominent O horizon, soil minerals had no apparent influence on the treatability of DOM.

  2. Treatability studies of alternative wastewaters for Metal Finishing Effluent Treatment Facility

    SciTech Connect

    Wittry, D.M.; Martin, H.L.

    1994-06-01

    The 300-M Area Liquid Effluent Treatment Facility (LETF) of the Savannah River Site (SRS) is an end-of-pipe industrial wastewater treatment facility that uses precipitation and filtration, which is the EPA Best Available Technology economically achievable for a Metal Finishing and Aluminum Form Industries. Upon the completion of stored waste treatment, the LETF will be shut down, because production of nuclear materials for reactors stopped at the end of the Cold War. The economic use of the LETF for the treatment of alternative wastewater streams is being evaluated through laboratory bench-scale treatability studies.

  3. Etiological explanation, treatability and preventability of childhood autism: a survey of Nigerian healthcare workers' opinion

    PubMed Central

    Bakare, Muideen Owolabi; Agomoh, Ahamefule O; Ebigbo, Peter O; Eaton, Julian; Okonkwo, Kevin O; Onwukwe, Jojo U; Onyeama, Gabriel M

    2009-01-01

    Background Because of their peculiar sociocultural background, healthcare workers in sub-Saharan African subcultures may have various conceptions on different aspects of autism spectrum disorders (ASD), such as etiology, treatment and issues of prognosis. These various conceptions, if different from current knowledge in literature about ASD, may negatively influence help-seeking behavior of parents of children with ASD who seek advice and information from the healthcare workers. This study assessed the opinions of healthcare workers in Nigeria on aspects of etiology, treatability and preventability of childhood autism, and relates their opinions to the sociodemographic variables. Methods Healthcare workers working in four tertiary healthcare facilities located in the south-east and south-south regions of Nigeria were interviewed with a sociodemographic questionnaire, personal opinion on etiology, treatability and preventability of childhood autism (POETPCA) questionnaire and knowledge about childhood autism among health workers (KCAHW) questionnaire to assess their knowledge and opinions on various aspects of childhood autism. Results A total of 134 healthcare workers participated in the study. In all, 78 (58.2%), 19 (14.2%) and 36 (26.9%) of the healthcare workers were of the opinion that the etiology of childhood autism can be explained by natural, preternatural and supernatural causes, respectively. One (0.7%) of the healthcare workers was unsure of the explanation of the etiology. Knowledge about childhood autism as measured by scores on the KCAHW questionnaire was the only factor significantly associated with the opinions of the healthcare workers on etiology of childhood autism. In all, 73 (54.5%) and 43 (32.1%), of the healthcare workers subscribed to the opinion that childhood autism is treatable and preventable respectively. Previous involvement with managing children with ASD significantly influenced the opinion of the healthcare workers in subscribing to

  4. Borehole Data Package for Nine CY 2006 Polyphosphate Treatability Testing Wells, 300-FF-5 Operable Unit, Hanford Site, Washington

    SciTech Connect

    Williams, Bruce A.

    2007-04-12

    Nine new CERCLA groundwater monitoring wells were installed in the 300-FF-5 Operable Unit in calendar year 2006 to fulfill commitments for the EM-20 funded polyphosphate treatability test. Nine new performance monitoring wells were drilled into the uppermost unconfined aquifer, to the Hanford formation - Ringold Formation contact boundary, and completed within the permeable Hanford fm. unit 1 gravel-dominated sequence. The overall objective of the polyphosphate treatability test is to evaluate the efficacy of using polyphosphate injections to treat 300 Area uranium contaminated groundwater in situ. The objective of this work was to install the performance monitoring network surrounding the existing treatability injection well C5000 (399-1-23) in support of the implementation of a field scale demonstration of the polyphosphate technology.

  5. Adsorption and release of amino acids mixture onto apatitic calcium phosphates analogous to bone mineral

    NASA Astrophysics Data System (ADS)

    El Rhilassi, A.; Mourabet, M.; El Boujaady, H.; Bennani-Ziatni, M.; Hamri, R. El; Taitai, A.

    2012-10-01

    Study focused on the interaction of adsorbate with poorly crystalline apatitic calcium phosphates analogous to bone mineral. Calcium phosphates prepared in water-ethanol medium at physiological temperature (37 °C) and neutral pH, their Ca/P ratio was between 1.33 and 1.67. Adsorbate used in this paper takes the mixture form of two essential amino acids L-lysine and DL-leucine which have respectively a character hydrophilic and hydrophobic. Adsorption and release are investigated experimentally; they are dependent on the phosphate type and on the nature of adsorbate L-lysine, DL-leucine and their mixture. Adsorption of mixture of amino acids on the apatitic calcium phosphates is influenced by the competition between the two amino acids: L-lysine and DL-leucine which exist in the medium reaction. The adsorption kinetics is very fast while the release kinetics is slow. The chemical composition of apatite has an influence on both adsorption and release. The interactions adsorbate-adsorbent are electrostatic type. Adsorption and release reactions of the amino acid mixture are explained by the existence of the hydrated surface layer of calcium phosphate apatite. The charged sbnd COOsbnd and sbnd NH3+ of adsorbates are the strongest groups that interact with the surface of apatites, the adsorption is mainly due to the electrostatic interaction between the groups sbnd COOsbnd of amino acids and calcium Ca2+ ions of the apatite. Comparative study of interactions between adsorbates (L-lysine, DL-leucine and their mixture) and apatitic calcium phosphates is carried out in vitro by using UV-vis and infrared spectroscopy IR techniques.

  6. Plant-driven weathering of apatite--the role of an ectomycorrhizal fungus.

    PubMed

    Smits, M M; Bonneville, S; Benning, L G; Banwart, S A; Leake, J R

    2012-09-01

    Ectomycorrhizal (EcM) fungi are increasingly recognized as important agents of mineral weathering and soil development, with far-reaching impacts on biogeochemical cycles. Because EcM fungi live in a symbiotic relationship with trees and in close contact with bacteria and archaea, it is difficult to distinguish between the weathering effects of the fungus, host tree and other micro-organisms. Here, we quantified mineral weathering by the fungus Paxillus involutus, growing in symbiosis with Pinus sylvestris under sterile conditions. The mycorrhizal trees were grown in specially designed sterile microcosms in which the supply of soluble phosphorus (P) in the bulk media was varied and grains of the calcium phosphate mineral apatite mixed with quartz, or quartz alone, were provided in plastic wells that were only accessed by their fungal partner. Under P limitation, pulse labelling of plants with (14)CO(2) revealed plant-to-fungus allocation of photosynthates, with 17 times more (14)C transferred into the apatite wells compared with wells with only quartz. Fungal colonization increased the release of P from apatite by almost a factor of three, from 7.5 (±1.1) × 10(-10) mol m(-2) s(-1) to 2.2 (±0.52) × 10(-9) mol m(-2) s(-1). On increasing the P supply in the microcosms from no added P, through apatite alone, to both apatite and orthophosphate, the proportion of biomass in roots progressively increased at the expense of the fungus. These three observations, (i) proportionately more plant energy investment in the fungal partner under P limitation, (ii) preferential fungal transport of photosynthate-derived carbon towards patches of apatite grains and (iii) fungal enhancement of weathering rate, reveal the tightly coupled plant-fungal interactions underpinning enhanced EcM weathering of apatite and its utilization as P source.

  7. Interrogating the Effects of Radiation Damage Annealing on Helium Diffusion Kinetics in Apatite

    NASA Astrophysics Data System (ADS)

    Willett, C. D.; Fox, M.; Shuster, D. L.

    2015-12-01

    Apatite (U-Th)/He thermochronology is commonly used to study landscape evolution and potential links between climate, erosion and tectonics. The technique relies on a quantitative understanding of (i) helium diffusion kinetics in apatite, (ii) an evolving 4He concentration, (iii) accumulating damage to the crystal lattice caused by radioactive decay[1], and (iv) the thermal annealing of such damage[2],[3], which are each functions of both time and temperature. Uncertainty in existing models of helium diffusion kinetics has resulted in conflicting conclusions, especially in settings involving burial heating through geologic time. The effects of alpha recoil damage annealing are currently assumed to follow the kinetics of fission track annealing (e.g., reference [3]), although this assumption is difficult to fully validate. Here, we present results of modeling exercises and a suite of experiments designed to interrogate the effects of damage annealing on He diffusivity in apatite that are independent of empirical calibrations of fission track annealing. We use the existing experimental results for Durango apatite[2] to develop and calibrate a new function that predicts the effects of annealing temperature and duration on measured diffusivity. We also present a suite of experiments conducted on apatite from Sierra Nevada, CA granite to establish whether apatites with different chemical compositions have the same behavior as Durango apatite. Crystals were heated under vacuum to temperatures between 250 and 500°C for 1, 10, or 100 hours. The samples were then irradiated with ~220 MeV protons to produce spallogenic 3He, the diffusant then used in step-heating diffusion experiments. We compare the results of these experiments and model calibrations to existing models. Citations: [1]Shuster, D., Flowers R., and Farley K., (2006), EPSL 249(3-4), 148-161; [2]Shuster, D. and Farley, K., (2009), GCA 73 (1), 6183-6196; [3]Flowers, R., Ketcham, R., Shuster, D. and Farley, K

  8. Acceleration of apatite nucleation on microrough bioactive titanium for bone-replacing implants.

    PubMed

    Aparicio, C; Manero, J M; Conde, F; Pegueroles, M; Planell, J A; Vallet-Regí, M; Gil, F J

    2007-09-01

    The viability of a new two-step method for obtaining bioactive microrough titanium surfaces for bone replacing implants has been evaluated. The method consists of (1) Grit blasting on titanium surface to roughen it; and (2) Thermo-chemical treating to obtain a bioactive surface with bone-bonding ability by means of nucleating and growing an apatite layer on the treated surface of the metal. The aim of this work is to evaluate the effect of surface roughness and chemical composition of the grit-blasting particles on the ability of the surfaces of nucleating and growing a homogeneous apatite layer. The determination and kinetics of the nucleation and growing of the apatite layer on the surfaces has mainly been studied with environmental scanning electron microscopy (ESEM) and grazing-incidence X-ray diffractometry. The results show that Al(2)O(3)-blasted and thermochemically-treated titanium surfaces accelerates nucleation of the apatite, whereas SiC-blasted and thermochemically-treated titanium surfaces inhibits apatite nucleation, compared with the well studied polished and thermochemically-treated titanium surfaces. The acceleration of the apatite nucleation on the Al(2)O(3)-blasted microrough titanium surfaces is because concave parts of the microroughness that are obtained during grit blasting provides to the rough and bioactive surfaces with a chemical- and electrostatic-favored situation for apatite nucleation. This consists of a high density of surface negative charges (also assisted by the nanoroughness of the surface obtained after the thermochemical treatment) and an increased concentration of the Ca(2+)-ions of the fluid, which have a limited mobility at the bottom of the concave parts. PMID:17295245

  9. Toxicity-directed approach of polyester manufacturing industry wastewater provides useful information for conducting treatability studies.

    PubMed

    Caffaro-Filho, Roberto A; Morita, Dione M; Wagner, Roger; Durrant, Lucia R

    2009-04-15

    A broader characterization of industrial wastewaters, especially in respect to hazardous compounds and their potential toxicity, is often necessary in order to determine the best practical treatment (or pretreatment) technology available to reduce the discharge of harmful pollutants to the environment or publicly owned treatment works. Using a toxicity-directed approach, this paper sets the base for a rational treatability study of polyester resin manufacturing. Relevant physical and chemical characteristics were determined. Respirometry was used for toxicity reduction evaluation after physical and chemical effluent fractionation. Of all the procedures investigated, only air stripping was significantly effective in reducing wastewater toxicity. Air stripping in pH 7 reduced toxicity in 18.2%, while in pH 11 a toxicity reduction of 62.5% was observed. Results indicated that toxicants responsible for the most significant fraction of the effluent's instantaneous toxic effect to unadapted activated sludge were organic compounds poorly or not volatilized in acid conditions. These results led to useful directions for conducting treatability studies which will be grounded on actual effluent properties rather than empirical or based on the rare specific data on this kind of industrial wastewater.

  10. Characterization and photocatalytic treatability of red water from Brazilian TNT industry.

    PubMed

    Ludwichk, Raquel; Helferich, Oliver Karil; Kist, Cristiane Patrícia; Lopes, Aline Chitto; Cavasotto, Thiago; Silva, Davi Costa; Barreto-Rodrigues, Marcio

    2015-08-15

    The current study aims to characterize and evaluate the photocatalytic treatability of the "red water" effluent from a Brazilian TNT production industry. Analyses were performed using physical, chemical, spectroscopic and chromatographic assays, which demonstrated that the effluent presented a significant pollution potential, mainly due to COD, BOD, solids and to the high concentration of nitroaromatic compounds such as 1,3,5-trinitrobenzene, 1-methyl-2,4-dinitrobenzene, 2-methyl-1,3-dinitrobenzene, 2,4,6-trinitrotoluene-3,5-dinitro-p-toluidine and 2-methyl-3,5-dinitro-benzoamine. By a modified sol-gel and a dip-coating technique, it was possible to obtain a TiO2 film on borosilicate glass substrate which functional composition and microstructure were characterized by infrared spectroscopy and scanning electron microscopy. The evaluation of the photocatalytic treatability using borosilicate-glass-TiO2 demonstrated high degradation efficiency. In this context, a reduction of 32 and 100% for COD and nitroaromatic compounds, respectively, was observed. Although the proposed photocatalytic process has found difficulties in reducing the content of organic matter and effluent color in the red water, its potential for degrading refractory chemical compounds such as the nitroaromatic ones enables it to be used as tertiary treatment.

  11. Treatability of TCE-contaminated clay soils at the Rinsewater Impoundment, Michoud Assembly Facility

    SciTech Connect

    Lucero, A.J.; Gilbert, V.P.; Hewitt, J.D.; Koran, L.J. Jr.; Jennings, H.L.; Donaldson, T.L.; West, O.R.; Cline, S.R.; Marshall, D.S.

    1995-02-01

    The Oak Ridge National Laboratory has conducted treatability studies on clay soils taken from the Rinsewater Impoundment at the National Aeronautics and Space Administration Michoud Assembly Facility. The soils are contaminated with up to 3000 mg/kg of trichloroethylene and cis-1,2-dichloroethylene, less than 10 mg/kg of trans-1,2-DCE, and less than 10 mg/kg of vinyl chloride. The goal of the study described in this report was to identify and test in situ technologies and/or develop a modified treatment regime to remove or destroy volatile organic compounds from the contaminated clay soils. Much of the work was based upon previous experience with mixed-region vapor stepping and mixed-region peroxidation. Laboratory treatments were performed on intact soil cores that were taken from contaminated areas at the Rinsewater Impoundment at MAF. Treatability studies were conducted on soil that was close to in situ conditions in terms of soil structure and contaminant concentrations.

  12. Characterization and photocatalytic treatability of red water from Brazilian TNT industry.

    PubMed

    Ludwichk, Raquel; Helferich, Oliver Karil; Kist, Cristiane Patrícia; Lopes, Aline Chitto; Cavasotto, Thiago; Silva, Davi Costa; Barreto-Rodrigues, Marcio

    2015-08-15

    The current study aims to characterize and evaluate the photocatalytic treatability of the "red water" effluent from a Brazilian TNT production industry. Analyses were performed using physical, chemical, spectroscopic and chromatographic assays, which demonstrated that the effluent presented a significant pollution potential, mainly due to COD, BOD, solids and to the high concentration of nitroaromatic compounds such as 1,3,5-trinitrobenzene, 1-methyl-2,4-dinitrobenzene, 2-methyl-1,3-dinitrobenzene, 2,4,6-trinitrotoluene-3,5-dinitro-p-toluidine and 2-methyl-3,5-dinitro-benzoamine. By a modified sol-gel and a dip-coating technique, it was possible to obtain a TiO2 film on borosilicate glass substrate which functional composition and microstructure were characterized by infrared spectroscopy and scanning electron microscopy. The evaluation of the photocatalytic treatability using borosilicate-glass-TiO2 demonstrated high degradation efficiency. In this context, a reduction of 32 and 100% for COD and nitroaromatic compounds, respectively, was observed. Although the proposed photocatalytic process has found difficulties in reducing the content of organic matter and effluent color in the red water, its potential for degrading refractory chemical compounds such as the nitroaromatic ones enables it to be used as tertiary treatment. PMID:25827271

  13. Aerobic treatability of waste effluent from the leather finishing industry. Master's thesis

    SciTech Connect

    Vinger, J.A.

    1993-12-01

    The Seton Company supplies finished leather products exclusively for the automotive industry. In the process of finishing leather, two types of wastewaters are generated. The majority of the wastewater is composed of water-based paint residuals while the remainder is composed of solvent-based coating residuals. Aerobic treatability studies were conducted using water-based and solvent-based waste recirculatory waters from the Seton Company's Saxton, Pennsylvania processing plant. The specific objective was to determine the potential for using aerobic biological processes to biodegrade the industry's wastes and determine the potential for joint treatment at the local publicly owned treatment works (POTW). This study was accomplished in two phases. Phase I was conducted during the Spring Semester 1993 and consisted of aerobic respirometer tests of the raw wastes and mass balance analysis. The results of Phase I were published in a report to the Seton Company as Environmental Resources Research Institute project number 92C.II40R-1. Phase II was conducted during the Summer Semester 1993 and consisted of bench-scale reactor tests and additional aerobic respirometer tests. The aerobic respirometer batch tests and bench-scale reactor tests were used to assess the treatability of solvent-based and water-based wastewaters and determine the degree of biodegradability of the wastewaters. Mass balance calculations were made using measured characteristics.

  14. Magnetite-apatite mineralization in Khanlogh iron deposit, northwest of Neyshaboor, NE Iran

    NASA Astrophysics Data System (ADS)

    Najafzadeh Tehrani, Parvin; Asghar Calagari, Ali; Velasco Roldan, Francisco; Simmonds, Vartan; Siahcheshm, Kamal

    2016-04-01

    Khanlogh iron deposit lies on Sabzehvar-Ghoochan Cenozoic magmatic belt in northwest of Neyshaboor, NE Iran. The lithologic units in this area include a series of sub-volcanic intrusive rocks like diorite porphyry, quartz-diorite porphyry, and micro-granodiorite of Oligocene age. Mineralization in this area occurred as veins, dissemination, and open space filling in brecciated zones within the host sub-volcanic intrusive bodies. Three distinct types of mineral associations can be distinguished, (1) diopside-magnetite, (2) magnetite-apatite, and (3) apatite-calcite. Microscopic examinations along with SEM and EPMA studies demonstrated that magnetite is the most common ore mineral occurring as solitary crystals. The euhedral magnetite crystals are accompanied by lamellar destabilized ilmenite and granular fluorapatite in magnetite-apatite ores. The results of EPMA revealed that the lamellar ilmenite, relative to host magnetite crystal, is notably enriched in MgO and MnO (average of 3.3 and 2.6 wt%, respectively; n=5), whereas magnetite is slighter enriched in Ti (TiO2 around 1.8 wt%) being average of MgO, MnO and V2O3 of 0.6wt%, 0.2wt%, and 0.6 wt% (respectively; n=20). Minerals such as chlorapatite, calcite, and chalcedony are also present in the magnetite-apatite ores. The samples from apatite-calcite ores contain coarse crystals of apatite and rhomboedral calcite. The plot of the EPMA data of Khanlogh iron ore samples on diagram of TiO2-V2O5 (Hou et al, 2011) illustrated that the data points lies between the well-known Kiruna and El Laco (Chile) iron deposits. The magnetite crystals in the sub-volcanic host rocks were possibly formed by immiscible iron oxide fluids during magmatic stage. However, the magnetite and apatite existing in the veins and breccia zones may have developed by high temperature hydrothermal fluids. Studies done by Purtov and Kotelnikova (1993) proved that the proportion of Ti in magnetite is related to fluoride complex in the hydrothermal

  15. Apatite formation behaviour during metasomatism in the Bathtub Intrusion (Babbitt deposit, Duluth Complex, USA)

    NASA Astrophysics Data System (ADS)

    Raič, Sara; Mogessie, Aberra; Krenn, Kurt; Hauzenberger, Christoph A.; Tropper, Peter

    2016-04-01

    The mineralized troctolitic Bathtub intrusion (Duluth Complex, NE-Minnesota) is known for its famous Cu-Ni-Sulfide±PGM Babbitt deposit, where platinum group minerals (PGMs) are either hosted by primary magmatic sulfides (base metal sulfides) or associated with hydrothermally altered portions. This secondary generation of PGMs is present in alteration patches and suggests the involvement of hydrothermal fluids in the mobilization of platinum-group elements (PGEs). Accessory fluorapatite in these samples reveals besides H2O- and CO2-rich primary fluid inclusions, textural and compositional variations that also record magmatic and metasomatic events. Based on detailed back-scattered electron imaging (BSE) and laser ablation-inductively coupled plasma-mass spectrometry (LA-ICPMS), a primary magmatic origin is reflected by homogeneous or zoned grains, where zoning patterns are either concentric or oscillatory, with respect to LREE. Late magmatic to hydrothermal processes are indicated by grains with bright LREE-enriched rims or conversion textures with REE-enriched patches in the interior of the apatite. A metasomatic formation of monazite from apatite is documented by the presence of monazite inclusions in apatite and newly grown monazite at altered apatite rims. They formed by the release of REEs from the apatite during a fluid-induced alteration, based on the coupled substitution Ca2+ + P5+ = REE3+ + Si4+ (Rønsbo 1989; Rønsbo 2008). Samples with monazite inclusions in apatite further display occurrences of PGMs associated with hydrothermal alteration patches (chlorite + amphibole). The presence of H2O- and CO2-rich fluid inclusions in apatite, the metasomatically induced monazite growth, as well as the occurrence of PGMs in hydrothermally alteration zones, also suggest the involvement of aqueous chloride complexes in a H2O dominated fluid in the transportation of LREE and redistribution of the second generation of PGEs. Rønsbo, J.G. (1989): Coupled substitutions

  16. Crystallinity in apatites: how can a truly disordered fraction be distinguished from nanosize crystalline domains?

    PubMed

    Celotti, Giancarlo; Tampieri, Anna; Sprio, Simone; Landi, Elena; Bertinetti, Luca; Martra, Gianmario; Ducati, Caterina

    2006-11-01

    In the last decade synthetic apatites mimicking the human natural one have been widely prepared and characterized from the physico-chemical point of view; however a shading zone is still remaining related to the evaluation and distinction of the less crystalline part, almost amorphous, and the crystallographically well ordered, nano-sized part, inside the apatite itself. Actually natural apatite forming bone tissue can include both types of crystals whose prevalence is dependent from the specific bone evolution stage and the specialized tissue performance. The quantitative description of such a combination usually represents a puzzling problem, but the result can also clarify the definition of "crystallinity in apatite" that appears still controversial. Many different synthetic apatites, including those nucleated on organic templates, were analyzed with different techniques (X-ray diffraction, transmission electron microscopy, and so on) to clarify the true nature of the disordered part. The results, manipulated by the classical methodologies devised for substances with highly perturbed structural order, led to establish that only specifically prepared amorphous calcium phosphate is really a glass, while the distorted portion coexisting with more or less crystalline regions is simply nanocrystalline. Moreover, at the conceptual limit of crystallinity tending to zero, the two models surprisingly cease to be conflicting.

  17. Fabrication and apatite inducing ability of different porous titania structures by PEO treatment.

    PubMed

    Rao, X; Chu, C L; Sun, Q; Zheng, Y Y

    2016-09-01

    Plasma electrolytic oxidation (PEO) was employed to grow different porous titania structures on Ti6Al4V alloy (TC4) substrate using various parameters. It was found that the PEO voltage and working frequency could affect the morphology, the pore size, the pore density, the thickness and the phase composition of titania structures. Thereafter, three typical porous titania structures with nanosize pores, microsize pores and microsize grooves were respectively selected to estimate their bioactivity using SBF immersion test. After soaking at different durations (3-28d), the surface morphology, the chemical composition as well as the phase structure of deposited apatite layers on porous titania were evaluated using SEM, EDS, and XRD. The formation of various biomimetic apatite layers indicated the different influence due to the characteristics of porous titania structures. The porous titania structure with nanosize pores could induce a fast apatite growth at the early immersion stage (~7d), while the one with microsize pores exhibited the best apatite inducing ability at long term immersion (~28d). Based on the experimental results, the formation mechanism of biomimetic apatite affected by the pore structure of titania was discussed as well.

  18. Spontaneous growth of a laminin-apatite nano-composite in a metastable calcium phosphate solution.

    PubMed

    Oyane, Ayako; Uchida, Masaki; Onuma, Kazuo; Ito, Atsuo

    2006-01-01

    We have previously reported that a laminin-apatite composite layer is formed on an ethylene-vinyl alcohol copolymer (EVOH) in a laminin-containing calcium phosphate (LCP) solution. In this work, the stability of the LCP solution and growth process of the laminin-apatite composite layer have been investigated. Dynamic light scattering technique revealed that the LCP solution was stable for periods as long as 24 h; it did not induce homogeneous precipitation of laminin or calcium phosphates in the solution. Analysis of the EVOH surface and the LCP solution showed that the laminin-apatite composite layer was formed via coprecipitation of laminin and apatite on the EVOH plate, i.e., spontaneous growing of apatite and simultaneous immobilization of laminin molecules or laminin-calcium phosphate nano-complexes onto its surface. Transmission electron microscopy also revealed that the laminin molecules in the resulting composite layer were not localized or aggregated, but were dispersed on a nano-scale in the entire layer. Because of this nano-composite structure, a large number of laminin molecules were stably immobilized on the EVOH plate. This may be responsible for the excellent cell adhesion properties of this type of composite material.

  19. Mechanisms by which the inhibition of specific intracellular signaling pathways increase osteoblast proliferation on apatite surfaces.

    PubMed

    Yang, Seungwon; Tian, Yu-Shun; Lee, Yun-Jung; Yu, Frank H; Kim, Hyun-Man

    2011-04-01

    Osteoblasts proliferate slowly on the surface of calcium phosphate apatite which is widely used as a substrate biomaterial in bone regeneration. Owing to poor adhesion signaling in the cells grown on the calcium phosphate surface, inadequate growth factor signaling is generated to trigger cell cycle progression. The present study investigated an intracellular signal transduction pathway involved in the slow cell proliferation in osteoblasts grown on the calcium phosphate surface. Small GTPase RhoA and phosphatase and tensin homolog (PTEN) were more activated in cells grown on the surface of calcium phosphate apatite than on tissue culture plate. Specific inhibition of RhoA and PTEN induced the cells on calcium phosphate apatite surface to proliferate at a similar rate as cells on tissue culture plate surface. Specific inhibition of ROCK, which is a downstream effector of RhoA and an upstream activator of PTEN also increased proliferation of these osteoblasts. Present results indicate that physical property of calcium phosphate crystals that impede cell proliferation may be surmounted by the inhibition of the RhoA/ROCK/PTEN pathway to rescue delayed proliferation of osteoblasts on the calcium phosphate apatite surface. In addition, specific inhibition of ROCK promoted cell migration and osteoblast differentiation. Inhibition of the RhoA/ROCK/PTEN intracellular signaling pathway is expected to enhance cell activity to promote and accelerate bone regeneration on the calcium phosphate apatite surface.

  20. Bioactive bredigite coating with improved bonding strength, rapid apatite mineralization and excellent cytocompatibility.

    PubMed

    Yi, Deliang; Wu, Chengtie; Ma, Bing; Ji, Heng; Zheng, Xuebin; Chang, Jiang

    2014-05-01

    Previous studies have shown that bredigite (Ca7MgSi4O16) bioceramics possessed excellent biocompatibility, apatite-mineralization ability and mechanical properties. In this paper, the bredigite coating on Ti-6Al-4 V substrate was prepared by plasma spraying technique. The main compositions of the coating were bredigite crystal phase with small parts of amorphous phases. The bonding strength of the coating to Ti-6Al-4 V substrate reached 49.8 MPa, which was significantly higher than that of hydroxyapatite coating and other silicate-based bioceramic coatings prepared by same method. After immersed in simulated body fluid for 2 days, a distinct apatite layer was deposited on the surface of bredigite coating, indicating that the prepared bredigite coating has excellent apatite-mineralization ability. The prepared bredigite coating supported the attachment and proliferation of rabbit bone marrow stem cells. The proliferation level of bone marrow stem cells was significantly higher than that on the hydroxyapatite coating. Our further study showed that the released SiO4 (4-) and Mg(2+) ions from bredigite coating as well as the formed nano-apatite layer on the coating surface might mainly contribute to the improvement of cell proliferation. The results indicated that the bredigite coating may be applied on orthopedic implants due to its excellent bonding strength, apatite mineralization and cytocompatibility.

  1. Characterization of a calcium phospho-silicated apatite with iron oxide inclusions

    NASA Astrophysics Data System (ADS)

    Desport, Barthélémy; Carpena, Joëlle; Lacout, Jean-Louis; Borschneck, Daniel; Gattacceca, Jérôme

    2011-02-01

    An iron oxide containing calcium phosphate-silicate hydroxyapatite was synthesized by calcination at 900 °C of a sample obtained by precipitation in basic aqueous solution of Ca, P, Si, Fe and Mg containing acidic solution made from dissolution of natural minerals. XRD and FTIR were used for crystallographic characterization of the main apatitic phase. Its composition was determined using ICP-AES. EDX coupled with SEM and TEM evidenced the heterogeneity of this compound and the existence of iron-magnesium oxide. Magnetic analyses highlighted that this phase was non-stoichiometric magnesioferrite (Mg 1.2Fe 1.8O 3.9) spherical nanoparticles. Those analyses also put into evidence the role of calcination in synthesis. Carbonates detected by FTIR and estimated by SEM-EDX in non-calcinated sample were removed from apatitic structure, and crystallization of apatite was enhanced during heating. Moreover, there was phase segregation that led to magnesioferrite formation.

  2. The quantitative determination of calcite associated with the carbonate-bearing apatites

    USGS Publications Warehouse

    Silverman, Sol R.; Fuyat, Ruth K.; Weiser, Jeanne D.

    1951-01-01

    The CO2 combined as calcite in carbonate-bearing apatites as been distinguished from that combined as carbonate-apatite, or present in some form other than calcite, by use of X-ray powder patterns, differential thermal analyses, and differential solubility tests. These methods were applied to several pure apatite minerals, to one fossil bone, and to a group of phosphorites from the Phosphoria formation of Permian age from Trail Canyon and the Conda mine, Idaho, and the Laketown district, Utah. With the exceptions of pure fluorapatite, pure carbonate-flueorapatite, and one phosphorite from Trail Canyon, these substances contain varying amounts of calcite, but in all the samples an appreciable part of the carbonite content is not present as calcite. The results of solubility tests, in which the particle size of sample and the length of solution time were varied, imply that the carbonate content is not due to shielded calcite entrapped along an internal network of surfaces.

  3. Young asteroidal fluid activity revealed by absolute age from apatite in carbonaceous chondrite

    NASA Astrophysics Data System (ADS)

    Zhang, Ai-Cheng; Li, Qiu-Li; Yurimoto, Hisayoshi; Sakamoto, Naoya; Li, Xian-Hua; Hu, Sen; Lin, Yang-Ting; Wang, Ru-Cheng

    2016-09-01

    Chondritic meteorites, consisting of the materials that have formed in the early solar system (ESS), have been affected by late thermal events and fluid activity to various degrees. Determining the timing of fluid activity in ESS is of fundamental importance for understanding the nature, formation, evolution and significance of fluid activity in ESS. Previous investigations have determined the relative ages of fluid activity with short-lived isotope systematics. Here we report an absolute 207Pb/206Pb isochron age (4,450+/-50 Ma) of apatite from Dar al Gani (DaG) 978, a type ~3.5, ungrouped carbonaceous chondrite. The petrographic, mineralogical and geochemical features suggest that the apatite in DaG 978 should have formed during metamorphism in the presence of a fluid. Therefore, the apatite age represents an absolute age for fluid activity in an asteroidal setting. An impact event could have provided the heat to activate this young fluid activity in ESS.

  4. Mechanism of apatite formation on hydrogen plasma-implanted single-crystal silicon

    NASA Astrophysics Data System (ADS)

    Liu, Xuanyong; Fu, Ricky K. Y.; Chu, Paul K.; Ding, Chuanxian

    2004-10-01

    Hydrogen is implanted into single-crystal silicon wafers using plasma ion immersion implantation to improve the surface bioactivity and the mechanism of apatite formation is investigated. Our micro-Raman and transmission electron microscopy results reveal the presence of a disordered silicon surface containing Si-H bonds after hydrogen implantation. When the sample is immersed in a simulated body fluid, the Si-H bonds on the silicon wafer initially react with water to produce a negatively charged surface containing the functional group (Si-O-) that subsequently induces the formation of apatite. A good understanding of the formation mechanism of apatite on hydrogen implanted silicon is not only important from the viewpoint of biophysics but also vital to the actual use of silicon-based microchips and MEMS inside a human body.

  5. Apatite (U-Th)/He thermochronology dataset interpretation: New insights from physical point of view

    NASA Astrophysics Data System (ADS)

    Gautheron, Cécile; Mbongo-Djimbi, Duval; Gerin, Chloé; Roques, Jérôme; Bachelet, Cyril; Oliviero, Erwan; Tassan-Got, Laurent

    2015-04-01

    The apatite (U-Th)/He (AHe) system has rapidly become a very popular thermochronometer to constrain burial and exhumation phases in a variety of geological contexts. However, the interpretation of AHe data depends on a precise knowledge of He diffusion in apatite. Several studies suggest that radiation damage generated by U and Th decay can create traps for He atoms, increasing He retention for irradiated minerals. The radiation damage also anneals with temperature and the amount of damage in an apatite crystal is at any time a balance between production and annealing, controlled by U-Th concentration, grain chemistry and thermal history (Flowers et al., 2009; Gautheron et al., 2009; 2013). However the models are not well constrained and do not fully explain the mechanism of He retention. In order to have a deeper insight on this issue, multidisciplinary studies on apatite combining diffusion experiments by Elastic Recoil Diffusion Analysis (ERDA) with a multi-scale theoretical diffusion calculation based on Density Functional Theory (DFT) and Kinetic Monte Carlo were performed. ERDA experiments were conducted on different macro-crystals, and we probed the shape of a He profile implanted into a planar and polished surface of the crystal. The helium profile evolves with temperature and allows quantifying the He diffusivity and damage impact. Additionally, DFT calculations of a damage-free crystal of apatite with different F and Cl compositions, in similar proportion as natural ones, have been run to find the favored paths of a helium atom between interstitial sites, leading to a computation of the activation energy and the diffusion coefficient. We show that damage free apatite crystals are characterized by low retention behavior and closure temperature range from 33-36°C for pure F-apatite to higher value for Cl riche apatite (up to 12°C higher), for typical grain size and cooling rate (Mbongo-Djimbi et al., in review). Using ERDA and DFT approaches, we

  6. Revised phosphate-water fractionation equation reassessing paleotemperatures derived from biogenic apatite

    NASA Astrophysics Data System (ADS)

    Pucéat, E.; Joachimski, M. M.; Bouilloux, A.; Monna, F.; Bonin, A.; Motreuil, S.; Morinière, P.; Hénard, S.; Mourin, J.; Dera, G.; Quesne, D.

    2010-09-01

    Oxygen isotopes of biogenic apatite have been widely used to reassess anomalous temperatures inferred from oxygen isotope ratios of ancient biogenic calcite, more prone to diagenetic alteration. However, recent studies have highlighted that oxygen isotope ratios of biogenic apatite differ dependent on used analytical techniques. This questions the applicability of the phosphate-water fractionation equations established over 25 years ago using earlier analytical techniques to more recently acquired data. In this work we present a new phosphate-water oxygen isotope fractionation equation based on oxygen isotopes determined on fish raised in aquariums at controlled temperature and with monitored water oxygen isotope composition. The new equation reveals a similar slope, but an offset of about + 2‰ to the earlier published equations. This work has major implications for paleoclimatic reconstructions using oxygen isotopes of biogenic apatite since calculated temperatures have been underestimated by about 4 to 8 °C depending on applied techniques and standardization of the analyses.

  7. Preliminary Apatite Fission Track Thermochronology of Wrangel Island, Arctic Russia

    NASA Astrophysics Data System (ADS)

    Dumitru, T. A.; Miller, E. L.

    2010-12-01

    Wrangel Island is part of a regional structural high that forms the continuation of the offshore Herald Arch and Chukchi Platform of Alaska. It is flanked on the north by the deep North Chukchi Basin, which in addition to Paleozoic strata, is inferred to contain up to 12 km of Beaufortian and Brookian (Late Jurassic to Tertiary) sediments (Dinkelman et al., 2008). To the south, ~E-W trending faults bound the Longa Basin that separates Wrangel from mainland Chukotka. This basin lies along strike of the early Tertiary Hope Basin in the Alaskan offshore. Wrangel Island itself exposes a broad, doubly-plunging anticlinorium-like structure cored by Neoproterozoic basement and flanked by Paleozoic shelf successions and a thick section of Triassic turbidites, representing about 5-7 km of structural section. The structural geology of Wrangel Island has been interpreted to represent a north-vergent Mesozoic fold and thrust belt linked by seismic reflection to the Herald Arch and then to the Lisburne Hills and the Brooks Range foreland fold and thrust belt (e.g. Kos’ko et al., 1993). However, deformation differs considerably from typical foreland fold-thrust structures of the Brooks Range as it is penetrative, involves large strains, and occurred under greenschist facies metamorphic conditions. Parts of the sequence exhibit mylonitic fabrics. Apatite fission track thermochronology of rocks from Wrangel Island can establishes the age of cooling to temperatures below ~ 100° C, providing temporal constraints on the uplift and erosional history of rocks that form this regional structural high. We analyzed seven fission track samples from a 9-km long N-S transect along the Kishchnikov River, from Triassic strata on the southern flank of the anticlinal structure to Devonian(?)-Mississippian feldspathic grits, conglomerates, and underlying Neoproterozoic igneous basement rocks in its core. All samples yielded statistically indistinguishable fission track ages averaging about 95

  8. TREATABILITY STUDIES USED TO TEST FOR EXOTHERMIC REACTIONS OF PLUTONIUM DECONTAMINATION CHEMICALS

    SciTech Connect

    EWALT, J.R.

    2005-06-06

    Fluor Hanford is decommissioning the Plutonium Finishing Plant (PFP) at the Hanford site in Eastern Washington. Aggressive chemicals are commonly used to remove transuranic contaminants from process equipment to allow disposal as low level waste. Chemicals being considered for decontamination of gloveboxes in PFP include cerium(IV) nitrate in a nitric acid solution, and proprietary commercial solutions that include acids, degreasers, and sequestering agents. Fluor's decontamination procedure involves application of chemical solutions as a spray on the contaminated surfaces, followed by a wipe-down with rags. This process effectively transfers the transuranic materials to the decontamination liquids, which are then absorbed by rags and packaged for disposal as TRU waste. Concerns regarding the safety of this procedure developed following a fire at Rocky Flats in 2003. The fire occurred in a glovebox that had been treated with cerium nitrate, which is one of the decontamination chemicals that Fluor Hanford has proposed to use. The investigation of the event was hampered by the copious use of chemicals and water to extinguish the fire, and was not conclusive regarding the cause. However, the reviewers noted that rags were found in the glovebox, suggesting that the combination of rags and chemicals may have contributed to the fire. With that uncertainty, Fluor began an investigation into the potential for fire when using the chemicals and materials in the decontamination process. The focus of this work has been to develop a disposal strategy that will provide a chemically stable waste form at expected Hanford waste storage temperatures. Treatability tests under CERCLA were used to assess the use of certain chemicals and wipes during the decontamination process. Chemicals being considered for decontamination of gloveboxes at PFP include cerium (IV) nitrate in a nitric acid solution, and proprietary commercial solutions as RadPro{trademark} that include acids, degreasers

  9. Differential fluorescence EEMs can be used to assess treatability of DOM during drinking water production

    NASA Astrophysics Data System (ADS)

    Lavonen, Elin; Kothawala, Dolly; Tranvik, Lars; Köhler, Stephan

    2014-05-01

    Fluorescence spectroscopy has been widely used to characterize fluorescent dissolved organic matter (FDOM) in various waters including during drinking water production. Commonly used techniques for data treatment include peak picking, indexes calculated from 2D emission spectra and modelling of fluorescence components using parallel factor analysis (PARAFAC). However, peak picking and indexes only use limited information from the fluorescence EEMs and PARAFAC requires a larger dataset and experience to perform. Because DOM is a major issue in drinking water production, and personnel at water treatment plants usually have limited time for advanced analysis we have developed a simple way of assessing the treatability of DOM in different waters using differential fluorescence. With this approach the removed fraction of FDOM is calculated from samples taken before and after a particular treatment process and the percentage of removed material assessed. Samples have been collected from four large water treatment plants in Sweden and analyzed for 3Dfluorescence, absorbance and DOC. The selective removal of DOM during e.g. flocculation and slow sand filtration as well as differences in experienced treatability between the treatment plants was described with differential fluorescence. Chemical flocculation is selective towards FDOM with red-shifted emission across the entire EEM. Red-shift has earlier been connected to condensation (i.e. decrease in H/C) and positively correlated to molecular size indicating that larger, humified molecules are being preferentially removed. During the biological process of slow sand filtration compounds with blue-shifted emission are targeted demonstrating selective removal of more freshly produced, microbial material. Disinfection with UV/NH2Cl and NaOCl was found to only target material with protein-like fluorescence suggesting that FDOM of this nature could be responsible for unwanted consumption of disinfection agent. Targeted removal

  10. [Inborn errors of metabolism are not hopeless; early identification of treatable conditions in children with intellectual disability].

    PubMed

    van Karnebeek, Clara D M

    2014-01-01

    Intellectual disability is a devastating condition affecting 2-3% of the global population; comorbidity is common. In addition to its lifelong impact on affected individuals, families and society as a whole, intellectual disability is associated with the highest healthcare costs of any disease. Inborn errors of metabolism constitute a group of rare genetic disorders that commonly manifest as an intellectual disability. For patients with these disorders, an increasing number of treatments are becoming available aimed at the pathophysiological mechanisms. A review of the literature identified 91 treatable inherited metabolic disorders; this was the basis for the development of a step-by-step diagnostic protocol and an app, Treatable-ID. A 2.5-year study in a tertiary setting treatable inborn errors of metabolism were identified as cause of intellectual disability in more than 5% of the children studied. It also showed that implementation of the diagnostic protocol reduced unnecessary costs and diagnostic delay. These results should motivate clinicians to aim diagnostic assessment of an individual with intellectual disability at treatable inborn errors of metabolism. Such an approach prevents brain damage, improves development and health and gives patients hope.

  11. SUPERFUND TREATABILITY CLEARINGHOUSE: SUMMARY REPORT ON THE FIELD INVESTIGATION OF THE SAPP BATTERY SITE JACKSON COUNTY, FLORIDA

    EPA Science Inventory

    This treatability study presents the results of field investigations at the Sapp Battery site in Florida, an abandoned battery recycling operation. The site is estimated to contain 14,300 cubic yards of soils with lead levels in excess of 1,000 ppm. The soils in the immediate v...

  12. SUPERFUND TREATABILITY CLEARINGHOUSE: BDAT INCINERATION OF CERCLA SARMS AT THE JOHN ZINK COMPANY TEST FACILITY (FINAL PROJECT REPORT)

    EPA Science Inventory

    This report presents the results of a treatability study of rotary kiln incineration of a synthetic "Superfund soil" bearing a wide range of chemical contaminants typically occurring at Superfund sites. This surrogate soil is referred to as a synthetic analytical reference ...

  13. In situ vitrification demonstration at Pit 1, Oak Ridge National Laboratory. Volume 1: Results of treatability study

    SciTech Connect

    Spalding, B.P.; Naney, M.T.; Cline, S.R.; Bogle, M.A.; Tixier, J.S.

    1997-12-01

    A treatability study was initiated in October 1993 to apply in situ vitrification (ISV) to at least two segments of Oak Ridge National Laboratory (ORNL) seepage Pit 1 by the end of fiscal year (FY) 1995. This treatability study was later extended to include all of Pit 1 and was performed to support a possible Interim Record of Decision or removal action for closure of one or more of the seepage pits and trenches beginning as early as FY 1997. This treatability study was carried out to establish the field-scale technical performance of ISV for (1) attaining the required depth, nominally 15 ft, to incorporate source contamination within and beneath the pits; (2) demonstrating field capability for the overlap of melt settings which will be necessary to achieve fused, melted segments of the source contamination; (3) demonstrating off-gas handling technology for accommodating and minimizing the volatilization of {sup 137}Cs; (4) demonstrating adequate site characterization techniques to predict ISV melting kinetics, processing temperatures, and product durability; and (5) promoting public acceptance of ISV technology by demonstrating its safety, implementability, site impacts, and air emissions and by coordinating the treatability study within the regulatory closure process. In April 1996 an expulsion of an estimated 10% of the 196 Mg (216 tons) melt body occurred resulting in significant damage to ISV equipment and, ultimately, led to an indefinite suspension of further ISV operations at Pit 1. This report summarizes the technical accomplishments and status of the project in fulfilling these objectives through September 1997.

  14. Treatability Test Report: Characterization of Vadose Zone Carbon Tetrachloride Source Strength Using Tomographic Methods at the 216-Z-9 Site

    SciTech Connect

    Truex, Michael J.; Carroll, Kenneth C.; Rohay, Virginia J.; Mackley, Rob D.; Parker, Kyle R.

    2012-09-28

    A treatability test was conducted in 2011 at the 216-Z-9 Trench to evaluate methods for collecting characterization information that supports refined assessment of SVE performance goals based on impact to groundwater. The characterization information can also provide input to operational strategies for continued SVE operation and decisions regarding closure of the SVE system or transition to other remedies, if necessary.

  15. EVALUATION OF CONTAMINANT LEACHABILITY FACTORS BY COMPARISON OF TREATABILITY STUDY DATA FOR MULTIPLE SOLIDIFIED/STABILIZED MATERIALS

    EPA Science Inventory

    Solidification/stabilization (S/S) technology is widely used in the treatment of hazardous waste and contaminated soil in the US. In a project sponsored by the US Navy and the USEPA, treatability test data were compiled into a data base listing contaminant concentration and matri...

  16. SUPERFUND TREATABILITY CLEARINGHOUSE: TECHNOLOGY DEMONSTRATION OF A THERMAL DESORPTION/UV PHOTOLYSIS PROCESS FOR DECONTAMINATING SOILS CONTAINING HERBICIDE ORANGE

    EPA Science Inventory

    This treatability study report presents the results of laboratory and field tests on the effectiveness of a new decontamination process for soils containing 2,4-D/2,4,5-T and traces of dioxin. The process employs three operations, thermal desorption, condensation and absorp...

  17. Adsorption of nucleotides on biomimetic apatite: The case of cytidine 5' monophosphate (CMP).

    PubMed

    Choimet, Maëla; Tourrette, Audrey; Drouet, Christophe

    2015-10-15

    The chemical interaction between DNA macromolecules and hard tissues in vertebrate is of foremost importance in paleogenetics, as bones and teeth represent a major substrate for the genetic material after cell death. Recently, the empirical hypothesis of DNA "protection" over time thanks to its adsorption on hard tissues was revisited from a physico-chemical viewpoint. In particular, the existence of a strong interaction between phosphate groups of DNA backbone and the surface of apatite nanocrystals (mimicking bone/dentin mineral) was evidenced on an experimental basis. In the field of nanomedicine, DNA or RNA can be used for gene transport into cells, and apatite nanocarriers then appear promising. In order to shed some more light on interactions between DNA molecules and apatite, the present study focuses on the adsorption of a "model" nucleotide, cytidine 5' monophosphate (CMP), on a carbonated biomimetic apatite sample. The follow-up of CMP kinetics of adsorption pointed out the rapidity of interaction with stabilization reached within few minutes. The adsorption isotherm could be realistically fitted to the Sips model (Langmuir-Freundlich) suggesting the influence of surface heterogeneities and adsorption cooperativity in the adsorption process. The desorption study pointed out the reversible character of CMP adsorption on biomimetic apatite. This contribution is intended to prove helpful in view of better apprehending the molecular interaction of DNA fragments and apatite compounds, independently of the application domain, such as bone diagenesis or nanomedicine. This study may also appear informative for researchers interested in the origins of life on Earth and the occurrence and behavior of primitive biomolecules.

  18. Adsorption of nucleotides on biomimetic apatite: The case of cytidine 5' monophosphate (CMP).

    PubMed

    Choimet, Maëla; Tourrette, Audrey; Drouet, Christophe

    2015-10-15

    The chemical interaction between DNA macromolecules and hard tissues in vertebrate is of foremost importance in paleogenetics, as bones and teeth represent a major substrate for the genetic material after cell death. Recently, the empirical hypothesis of DNA "protection" over time thanks to its adsorption on hard tissues was revisited from a physico-chemical viewpoint. In particular, the existence of a strong interaction between phosphate groups of DNA backbone and the surface of apatite nanocrystals (mimicking bone/dentin mineral) was evidenced on an experimental basis. In the field of nanomedicine, DNA or RNA can be used for gene transport into cells, and apatite nanocarriers then appear promising. In order to shed some more light on interactions between DNA molecules and apatite, the present study focuses on the adsorption of a "model" nucleotide, cytidine 5' monophosphate (CMP), on a carbonated biomimetic apatite sample. The follow-up of CMP kinetics of adsorption pointed out the rapidity of interaction with stabilization reached within few minutes. The adsorption isotherm could be realistically fitted to the Sips model (Langmuir-Freundlich) suggesting the influence of surface heterogeneities and adsorption cooperativity in the adsorption process. The desorption study pointed out the reversible character of CMP adsorption on biomimetic apatite. This contribution is intended to prove helpful in view of better apprehending the molecular interaction of DNA fragments and apatite compounds, independently of the application domain, such as bone diagenesis or nanomedicine. This study may also appear informative for researchers interested in the origins of life on Earth and the occurrence and behavior of primitive biomolecules. PMID:26117294

  19. Adsorption of nucleotides on biomimetic apatite: The case of adenosine 5‧ triphosphate (ATP)

    NASA Astrophysics Data System (ADS)

    Hammami, Khaled; El-Feki, Hafed; Marsan, Olivier; Drouet, Christophe

    2016-01-01

    ATP is a well-known energy supplier in cells. The idea to associate ATP to pharmaceutical formulations/biotechnological devices to promote cells activity by potentially modulating their microenvironment thus appears as an appealing novel approach. Since biomimetic nanocrystalline apatites have shown great promise for biomedical applications (bone regeneration, cells diagnostics/therapeutics, …), thanks to a high surface reactivity and an intrinsically high biocompatibility, the present contribution was aimed at exploring ATP/apatite interactions. ATP adsorption on a synthetic carbonated nanocrystalline apatite preliminarily characterized (by XRD, FTIR, Raman, TG-DTA and SEM-EDX) was investigated in detail, pointing out a good agreement with Sips isothermal features. Adsorption characteristics were compared to those previously obtained on monophosphate nucleotides (AMP, CMP), unveiling some specificities. ATP was found to adsorb effectively onto biomimetic apatite: despite smaller values of the affinity constant KS and the exponential factor m, larger adsorbed amounts were reached for ATP as compared to AMP for any given concentration in solution. m < 1 suggests that the ATP/apatite adsorption process is mostly guided by direct surface bonding rather than through stabilizing intermolecular interactions. Although standard ΔGads ° was estimated to only -4 kJ/mol, the large value of Nmax led to significantly negative effective ΔGads values down to -33 kJ/mol, reflecting the spontaneous character of adsorption process. Vibrational spectroscopy data (FTIR and Raman) pointed out spectral modifications upon adsorption, confirming chemical-like interactions where both the triphosphate group of ATP and its nucleic base were involved. The present study is intended to serve as a basis for future research works involving ATP and apatite nanocrystals/nanoparticles in view of biomedical applications (e.g. bone tissue engineering, intracellular drug delivery, …).

  20. Green apatites: hydride ions, electrons and their interconversion in the crystallographic channel.

    PubMed

    Hayashi, Katsuro; Hosono, Hideo

    2016-03-21

    Hydride (H(-)) ions and electrons in channel sites of the lattice of calcium phosphate apatites are characterized. Solid-state chemical reduction using TiH2 is effective for doping of H(-) ions into apatites. Irradiation of the H(-) ion-doped apatite with ultraviolet (UV) light induces green coloration. Electron paramagnetic resonance (EPR) reveals that this colour centre is attributed to electrons captured at a vacant anion site in the crystallographic channel, forming F(+) centres. Transient H(0) atoms are detected at low temperatures by EPR. The concentration of UV-induced electrons in the apatite at room temperature decays according to second-order kinetics because of the chemical reactions involving two electrons; overall, electron generation and thermal decay can be described as: H(-) + O(2-) ↔ 2e(-) + OH(-). (1)H magic angle spinning nuclear magnetic resonance spectroscopy is used to identify H(-) ions in the apatite, which are characterized by a chemical shift of +3.4 ppm. Various types of O-H groups including OH(-) ions in the channel and protons bound to phosphate groups are concurrently formed, and are identified by considering the relationship between the O-H stretching frequency and the (1)H chemical shift. The complementary results obtained by EPR and NMR reveal that the H(-) ions and transient H(0) atoms are located at the centre of Ca3 triangles in the apatite, while the electrons are located in the centre of Ca6 octahedra. These findings provide an effective approach for identifying new classes of mixed-oxide-hydride or -electride crystals. PMID:26928237

  1. Green apatites: hydride ions, electrons and their interconversion in the crystallographic channel.

    PubMed

    Hayashi, Katsuro; Hosono, Hideo

    2016-03-21

    Hydride (H(-)) ions and electrons in channel sites of the lattice of calcium phosphate apatites are characterized. Solid-state chemical reduction using TiH2 is effective for doping of H(-) ions into apatites. Irradiation of the H(-) ion-doped apatite with ultraviolet (UV) light induces green coloration. Electron paramagnetic resonance (EPR) reveals that this colour centre is attributed to electrons captured at a vacant anion site in the crystallographic channel, forming F(+) centres. Transient H(0) atoms are detected at low temperatures by EPR. The concentration of UV-induced electrons in the apatite at room temperature decays according to second-order kinetics because of the chemical reactions involving two electrons; overall, electron generation and thermal decay can be described as: H(-) + O(2-) ↔ 2e(-) + OH(-). (1)H magic angle spinning nuclear magnetic resonance spectroscopy is used to identify H(-) ions in the apatite, which are characterized by a chemical shift of +3.4 ppm. Various types of O-H groups including OH(-) ions in the channel and protons bound to phosphate groups are concurrently formed, and are identified by considering the relationship between the O-H stretching frequency and the (1)H chemical shift. The complementary results obtained by EPR and NMR reveal that the H(-) ions and transient H(0) atoms are located at the centre of Ca3 triangles in the apatite, while the electrons are located in the centre of Ca6 octahedra. These findings provide an effective approach for identifying new classes of mixed-oxide-hydride or -electride crystals.

  2. Mineralogy and geochemistry of Fe-Ti oxide and apatite (nelsonite) deposits and evaluation of the liquid immiscibility hypothesis.

    USGS Publications Warehouse

    Kolker, A.

    1982-01-01

    The modal mineralogy for 32 Fe-Ti oxides and apatites supports the 2:1 oxide:apatite ratio for these samples from New York, Quebec, Norway and Sweden. Accessory minerals include: biotite, clinoamphibole, spinel, zircon and sulphides, oxygen fugacities range from 10-11 to 10-20, and T 600o to 1000oC. - K.A.R.

  3. Growth of apatite on chitosan-multiwall carbon nanotube composite membranes

    NASA Astrophysics Data System (ADS)

    Yang, Jun; Yao, Zhiwen; Tang, Changyu; Darvell, B. W.; Zhang, Hualin; Pan, Lingzhan; Liu, Jingsong; Chen, Zhiqing

    2009-07-01

    Bioactive membranes for guided tissue regeneration would be of value for periodontal therapy. Chitosan-multiwall carbon nanotube (CS-MWNT) composites were treated to deposit nanoscopic apatite for MWNT proportions of 0-4 mass%. Fourier-transform infrared spectroscopy, scanning electron microscopy, energy-dispersive X-ray analysis, and X-ray diffraction were used for characterization. Apatite was formed on the CS-MWNT composites at low MWNT concentrations, but the dispersion of the MWNT affects the crystallite size and the Ca/P molar ratio of the composite. The smallest crystallite size was 9 nm at 1 mass% MWNT.

  4. Apatite: A New Tool For Understanding The Temporal Variability Of Magmatic Volatile Contents

    NASA Astrophysics Data System (ADS)

    Stock, M. J.; Humphreys, M.; Smith, V.; Pyle, D. M.; Isaia, R.

    2015-12-01

    The apatite crystal structure is capable of incorporating H2O, F and Cl, as well as trace CO2 and sulphur. These can be related to parental magma compositions through application of a series of pressure and temperature-dependent exchange reactions (Piccoli and Candela, 1994), permitting apatite crystals to preserve a record of all major volatile species in the melt. Furthermore, due to the general incompatibility of P in other rock-forming minerals, apatite is ubiquitous in igneous systems and often begins crystallising early, such that apatite inclusions within phenocrysts record melt volatile contents throughout magmatic differentiation. In this work, we compare the compositions of apatite inclusions and microphenocrysts with pyroxene-hosted melt inclusions from the Astroni 1 eruption of Campi Flegrei, Italy. These data are coupled with magmatic differentiation models (Gualda et al., 2012), experimental volatile solubility data (Webster et al., 2014) and thermodynamic models of apatite compositional variations (Piccoli and Candela, 1994) to determine a time-series of magmatic volatile evolution in the build-up to eruption. We find that apatite halogen/OH ratios decreased through magmatic differentiation, while melt inclusion F and Cl concentrations increased. Melt inclusion H2O contents are constant at ~2.5 wt%. These data are best explained by volatile-undersaturated differentiation over most of the crystallisation history of the Astroni 1 melt, with melt inclusion H2O contents reset during ascent, due to rapid H diffusion through the phenocryst hosts (Woods et al., 2000). Given the rapid diffusivity of volatiles in apatite (Brenan, 1993), preservation of undersaturated compositions in microphenocrysts suggests that saturation was only achieved a few days to months before eruption and that it may have been the transition into a volatile-saturated state that ultimately triggered eruption. Piccoli and Candela, 1994. Am. J. of Sc., 294, 92-135. Gualda et al., 2012

  5. The present day formation of apatite in Mexican continental margin sediments

    NASA Astrophysics Data System (ADS)

    Jahnke, Richard A.; Emerson, Steven R.; Roe, Kevin K.; Burnett, William C.

    1983-02-01

    Results of pore water and sediment analyses from the western Mexican continental margin strongly suggest the present day formation of apatite. The interstitial water phosphate and fluoride profiles indicate chemical removal at a depth which corresponds to a large maximum in the phosphorus content of the sediments. Apatite is identified within this maximum via X-ray diffraction but is elsewhere undetectable in the core. Radioisotopic thorium, uranium, and radium data support the conclusion that this deposit is modern. The present day depositional environment is consistent with those reported by other workers for phosphorite formation with the exception that pore water magnesium is not depleted below its seawater value.

  6. Bench- and pilot-scale thermal desorption treatability studies on pesticide-contaminated soils from Rocky Mountain Arsenal

    SciTech Connect

    Swanstrom, C.P.; Besmer, M.

    1995-03-09

    Thermal desorption is being considered as a potential remediation technology for pesticide-contaminated soils at the Rocky Mountain Arsenal (RMA) in Denver, Colorado. From 1988 through 1992, numerous laboratory- and bench-scale indirect-heated thermal desorption (IHTD) treatability studies have been performed on various soil medium groups from the arsenal. RMA has contracted Argonne National Laboratory to conduct a pilot-scale direct-fired thermal desorption (DFTD) treatability study on pesticide-contaminated RMA soil. The purpose of this treatability study is to evaluate the overall effectiveness of the DFTD technology on contaminated RMA soils and to provide data upon which future conceptual design assumptions and cost estimates for a full-scale system can be made. The equipment used in the DFTD treatability study is of large enough scale to provide good full-scale design parameters and operating conditions. The study will also provide valuable-emissions and materials-handling data. Specifically this program will determine if DFTD can achieve reductions in soil contamination below the RMA preliminary remediation goals (PRGs), define system operating conditions for achieving the PRGs, and determine the fate of arsenic and other hazardous metals at these operating conditions. This paper intends to compare existing data from a bench-scale IHTD treatability study using equipment operated in the batch mode to new data from a pilot-scale DFTD operated in a parallel-flow continuous mode. Delays due to materials-handling problems and permit issues have delayed the start of the pilot-scale DFTD testing. The first pilot-scale test is scheduled for the flat week in January 1995. The available data will be presented March 9, 1995, at the Seventh Annual Gulf Coast Environmental Conference in Houston, Texas.

  7. Normal-pressure hydrocephalus and the saga of the treatable dementias

    SciTech Connect

    Friedland, R.P. )

    1989-11-10

    A case study of a 74-year-old woman is presented which illustrates the difficulty of understanding dementing illnesses. A diagnosis of normal-pressure hydrocephalus (NPH) was made because of the development of abnormal gait, with urinary incontinence and severe, diffuse, white matter lesions on the MRI scan. Computed tomographic, MRI scans and positron emission tomographic images of glucose use are presented. The treatable dementias are a large, multifaceted group of illnesses, of which NPH is one. The author proposes a new term for this disorder commonly known as NPH because the problem with the term normal-pressure hydrocephalus is that the cerebrospinal fluid pressure is not always normal in the disease.

  8. Two Unusual but Treatable Causes of Refractory Ascites After Liver Transplantation.

    PubMed

    Novelli, P M; Shields, J; Krishnamurthy, V; Cho, K

    2015-12-01

    Refractory ascites (RA) is thought to complicate the postoperative course of 5-7% (Nishida et al. in Am J Transplant. 6: 140-149, 2006; Gotthardt et al. in Ann Transplant. 18: 378-383, 2013) of liver transplant recipients. RA after liver transplantation is often a frustrating diagnostic dilemma with few good management options unless an obvious mechanical factor is identified. Supportive therapies often fail until a treatable precipitating cause is identified and removed. We describe two patients who developed RA following liver transplantation for primary sclerosing cholangitis, and hepatitis C and alcoholic liver disease, respectively. The cause for RA was hyperkinetic portal hypertension secondary to splenomegaly in the first case and a pancreatic AVM in the 2nd case. After failure of other interventions, surgical splenectomy resulted in immediate and durable resolution of the previously intractable ascites. PMID:26017456

  9. Treatability Testing of an In Situ Biostimulation Barrier for Nitrate and Chromium Treatment - 9126

    SciTech Connect

    Truex, Michael J.; Vermeul, Vincent R.; Fruchter, Jonathan S.

    2008-11-14

    An ongoing treatability test is evaluating in situ biostimulation at the 100-D Area of the Hanford Site in Richland, Washington. This test is part of a strategy to couple multiple technologies to accelerate cleanup of hexavalent-chromium contaminated groundwater discharging into the Columbia River. A permeable chemical reducing barrier was previously applied as the primary treatment to prevent the chromium plume from reaching the river at concentrations that exceed regulatory standards. In situ biostimulation is intended to provide supplemental treatment upgradient of this chemical treatment barrier by reducing the concentration of the primary oxidizing species in groundwater (i.e., nitrate and dissolved oxygen) and chromium, thereby increasing the longevity of the chemical barrier and helping to diminish the chromium plume.

  10. Biodegradability oriented treatability studies on high strength segregated wastewater of a woolen textile dyeing plant.

    PubMed

    Baban, Ahmet; Yediler, Ayfer; Ciliz, NilgunKiran; Kettrup, Antonius

    2004-11-01

    Textile dyeing and finishing industry involves considerable amount of water usage as well as polluted and highly colored wastewater discharges. Biological treatability by means of mineralization, nitrification and denitrification of high strength woolen textile dye bathes, first- and second-rinses is presented. COD fractionation study was carried out and kinetic parameters were determined. Biodegradability of organic compounds in highly loaded composite wastewater after segregation and the effluent of applied biological treatment of high strength composite wastewater were measured by determining oxygen consumption rates. The results were used in terms of assessing an alternative method for inert COD fractionation. The study implied that about 80% soluble COD, 50% color and 75% toxicity reduction were possible by single sludge biological processes. Sixteen per cent of total COD was found to be initially inert. Inert fraction was increased to 22% by production of soluble and particulate microbial products through biological treatment. PMID:15488936

  11. Thermal and biological treatability studies on explosives-contaminated soil from a DOD site

    SciTech Connect

    Shultz, S.R.; Taylor, C.; Shultz, D.W.R.; Cichelli, J.; Pinion, J.

    1994-12-31

    Laboratory- and bench-scale treatability studies were conducted on explosives-contaminated soil from the former Nebraska Ordnance Plant (NOP) Site by RUST Environment and Infrastructure (RUST) for the U.S. Army Corps of Engineers (USACE) in order to obtain site-specific information for technologies evaluated in the Feasibility Study for the site. Both thermal and biological treatment were identified in the Feasibility Study as technologies that could potentially be used to remediate the explosives-contaminated soil at the site. However, additional information specific to the chemical concentrations and soil properties of the site was required to fully evaluate these technologies. Therefore, these studies were initiated in order to gain more information. The studies summarized in this paper include a rotary kiln incineration and geotechnical study conducted by RUST, Cross/Tessitore and Associates (C/TA) under subcontract to RUST, and a biological treatment study conducted by Radian Corporation (Radian) under subcontract to RUST.

  12. Treatability study for removal of leachable mercury in crushed fluorescent lamps

    SciTech Connect

    Bostick, W.D.; Beck, D.E.; Bowser, K.T.

    1996-02-01

    Nonserviceable fluorescent lamps removed from radiological control areas at the Oak Ridge Department of Energy facilities have been crushed and are currently managed as mixed waste (hazardous and radiologically contaminated). We present proposed treatment flowsheets and supporting treatability study data for conditioning this solid waste residue so that it can qualify for disposal in a sanitary landfill. Mercury in spent fluorescent lamps occurs primarily as condensate on high-surface-area phosphor material. It can be solubilized with excess oxidants (e.g., hypochlorite solution) and stabilized by complexation with halide ions. Soluble mercury in dechlorinated saline solution is effectively removed by cementation with zero-valent iron in the form of steel wool. In packed column dynamic flow testing, soluble mercury was reduced to mercury metal and insoluble calomel, loading > 1.2 g of mercury per grain of steel wool before an appreciable breakthrough of soluble mercury in the effluent.

  13. Stabilization of liquid low-level and mixed wastes: a treatability study

    SciTech Connect

    Carson, S.; Cheng, Yu-Cheng; Yellowhorse, L.; Peterson, P.

    1996-02-01

    A treatability study has been conducted on liquid low-level and mixed wastes using the stabilization agents Aquaset, Aquaset II, Aquaset II-H, Petroset, Petroset-H, and Petroset and Petroset II. A total of 40 different waste types with activities ranging from 10{sup {minus}14} to 10{sup {minus}4} curies/ml have been stabilized. Reported data for each waste include its chemical and radiological composition and the optimum composition or range of compositions (weight of agent/volume of waste) for each stabilization agent used. All wastes were successfully stabilized with one or more of the stabilization agents and all final waste forms passed the Paint Filter Liquids Test (EPA Method 9095).

  14. Gunite and Associated Tanks Treatability Study Equipment Testing at the Tanks Technology Cold Test Facility

    SciTech Connect

    Burks, BL

    2001-02-27

    This report provides a summary of the cold tests performed on the equipment to be used in the Gunite and Associated Tanks Treatability Study. The testing was performed from June 1996 to May 1997 at the Tanks Technology Cold Test Facility located at the 7600 complex at Oak Ridge National Laboratory. Testing of specific equipment grouped into the following sections: (1) Modified Light-Duty Utility Arm Testing, (2) Remotely Operated Vehicle Testing, (3) Waste Dislodging and Conveyance System and Balance of Plant Equipment Testing, (4) Camera and Lighting System Testing, and (5) Characterization End-Effector Testing. Each section contains descriptions of a series of tests that summarize the test objectives, testing performed, and test results. General conclusions from the testing are also provided.

  15. Deep Vadose Zone Treatability Test for the Hanford Central Plateau: Interim Post-Desiccation Monitoring Results

    SciTech Connect

    Truex, Michael J.; Oostrom, Martinus; Strickland, Christopher E.; Johnson, Timothy C.; Johnson, Christian D.; Clayton, Ray E.; Chronister, Glen B.

    2013-09-01

    A field test of desiccation is being conducted as an element of the deep vadose zone treatability test program. Desiccation technology relies on removal of water from a portion of the subsurface such that the resultant low moisture conditions inhibit downward movement of water and dissolved contaminants. Previously, a field test report (Truex et al. 2012a) was prepared describing the active desiccation portion of the test and initial post-desiccation monitoring data. Additional monitoring data have been collected at the field test site during the post-desiccation period and is reported herein along with interpretation with respect to desiccation performance. This is an interim report including about 2 years of post-desiccation monitoring data.

  16. Mutations in BCKD-kinase lead to a potentially treatable form of autism with epilepsy.

    PubMed

    Novarino, Gaia; El-Fishawy, Paul; Kayserili, Hulya; Meguid, Nagwa A; Scott, Eric M; Schroth, Jana; Silhavy, Jennifer L; Kara, Majdi; Khalil, Rehab O; Ben-Omran, Tawfeg; Ercan-Sencicek, A Gulhan; Hashish, Adel F; Sanders, Stephan J; Gupta, Abha R; Hashem, Hebatalla S; Matern, Dietrich; Gabriel, Stacey; Sweetman, Larry; Rahimi, Yasmeen; Harris, Robert A; State, Matthew W; Gleeson, Joseph G

    2012-10-19

    Autism spectrum disorders are a genetically heterogeneous constellation of syndromes characterized by impairments in reciprocal social interaction. Available somatic treatments have limited efficacy. We have identified inactivating mutations in the gene BCKDK (Branched Chain Ketoacid Dehydrogenase Kinase) in consanguineous families with autism, epilepsy, and intellectual disability. The encoded protein is responsible for phosphorylation-mediated inactivation of the E1α subunit of branched-chain ketoacid dehydrogenase (BCKDH). Patients with homozygous BCKDK mutations display reductions in BCKDK messenger RNA and protein, E1α phosphorylation, and plasma branched-chain amino acids. Bckdk knockout mice show abnormal brain amino acid profiles and neurobehavioral deficits that respond to dietary supplementation. Thus, autism presenting with intellectual disability and epilepsy caused by BCKDK mutations represents a potentially treatable syndrome.

  17. 3-phosphoglycerate dehydrogenase deficiency: a case report of a treatable cause of seizures.

    PubMed

    Coşkun, Turgay; Aydin, Halil Ibrahim; Kiliç, Mustafa; Dursun, Ali; Haliloğlu, Göknur; Topaloğlu, Haluk; Karli-Oğuz, Kader; de Koning, Tom J

    2009-01-01

    Serine deficiency disorders are a new group of neurometabolic diseases resulting from a deficiency in one of the three enzymes in the biosynthetic pathway of L-serine. Deficiency of the enzyme 3-phosphoglycerate dehydrogenase (3-PGDH), which catalyzes the first step in the biosynthetic pathway, leads to congenital microcephaly, severe psychomotor retardation, and intractable seizures. We report a 4 1/2-year-old boy who presented with congenital microcephaly, psychomotor retardation, hypertonia, strabismus, and drug-resistant seizures due to 3-PGDH deficiency. His seizures responded to L-serine and glycine supplementation only. This potentially treatable disease should be borne in mind in patients with congenital microcephaly, psychomotor retardation and seizures. A timely diagnosis based on the detection of low cerebrospinal fluid levels of L-serine and glycine is expected to further increase the success of L-serine and glycine supplementation in these patients. PMID:20196394

  18. Effects of apatite particle size in two apatite/collagen composites on the osteogenic differentiation profile of osteoblastic cells

    PubMed Central

    HATAKEYAMA, WATARU; TAIRA, MASAYUKI; CHOSA, NAOYUKI; KIHARA, HIDEMICHI; ISHISAKI, AKIRA; KONDO, HISATOMO

    2013-01-01

    The development of new osteoconductive bone substitute materials is expected in medicine. In this study, we attempted to produce new hydroxylapatite (HAP)/collagen (Col) composites using two HAP particles of different sizes and porcine type I collagen. The two HAP particles were either nano-sized (40 nm in average diameter; n-HAP) or had macro-pore sizes of 0.5–1.0 mm in length with fully interconnected pores (m-HAP). The aim of this study was to investigate the effects of apatite particle size in two HAP/Col composites on the osteogenic differentiation profile in osteoblast-like cells (SaOS-2). We created a collagen control sponge (Col) and two HAP/Col composite sponges (n-HAP/Col and m-HAP/Col) using freeze-drying and dehydrothermal cross-linking techniques, and then punched out samples of 6 mm in diameter and 1 mm in height. The SaOS-2 cells were cultured on three test materials for 1, 2, 3 and 4 weeks. Total RNA was extracted from the cultured cells and the expression of osteogenic differentiation-related genes was evaluated by reverse transcription PCR (RT-PCR) using primer sets of alkaline phosphatase (ALP), type 1 collagen (COL1), bone sialoprotein (BSP) and osteocalcin precursor [bone gamma-carboxyglutamate (gla) protein (BGLAP)] genes, as well as the β-actin gene. The cells were also cultured on Col, n-HAP/Col and m-HAP/Col specimens for 1 and 4 weeks, and were then observed under a scanning electron microscope (SEM). The experimental results were as follows: RT-PCR indicated that osteogenic differentiation, particularly the gene expression of BSP, was most accelerated when the cells were cultured on n-HAP/Col specimens, followed by m-HAP/Col, whilst the weakest accelaeration was observed when the cells were cultured on Col specimens. As shown by the SEM images, the SaOS-2 cells were fibroblastic when cultured on Col specimens for up to 4 weeks; they were fibroblastic when cultured on n-HAP/Col specimens for 1 week, but appeared as spheroids, while

  19. 100-D Area In Situ Redox Treatability Test for Chromate-Contaminated Groundwater

    SciTech Connect

    Williams, Mark D.; Vermeul, Vincent R.; Szecsody, James E.; Fruchter, Jonathan S.

    2000-10-12

    A treatability test was conducted for the In Situ Redox Manipulation (ISRM) technology at the 100 D Area of the U. S. Department of Energy's Hanford Site. The target contaminant was dissolved chromate in groundwater. The ISRM technology creates a permeable subsurface treatment zone to reduce mobile chromate in groundwater to an insoluble form. The ISRM permeable treatment zone is created by reducing ferric iron to ferrous iron within the aquifer sediments, which is accomplished by injecting aqueous sodium dithionite into the aquifer and then withdrawing the reaction products. The goal of the treatability test was to create a linear ISRM barrier by injecting sodium dithionite into five wells. Well installation and site characterization activities began in spring 1997; the first dithionite injection took place in September 1997. The results of this first injection were monitored through the spring of 1998. The remaining four dithionite injections were carried out in May through July of 1998.These five injections created a reduced zone in the Hanford unconfined aquifer approximately 150 feet in length (perpendicular to groundwater flow) and 50 feet wide. The reduced zone extended over the thickness of the unconfined zone. Analysis of post-emplacement groundwater samples showed concentrations of chromate, in the reduced zone decreased from approximately 1.0 mg/L before the tests to below analytical detection limits (<0.007 mg/L). Chromate concentrations also declined in downgradient monitoring wells to as low as 0.020 mg/L. These data, in addition to results from pre-test reducible iron characterization, indicate the barrier should be effective for 20 to 25 years. The 100-D Area ISRM barrier is being expanded to a length of up to 2,300 ft to capture a larger portion of the chromate plume.

  20. Treatability test plan for the 200-BP-1 prototype surface barrier

    SciTech Connect

    Not Available

    1993-06-01

    The US Department of Energy (DOE), Hanford Site, in Washington State is organized into numerically designated operational areas including the 100, 200, 300, 400, 600, and 1100 Areas. The US Environmental Protection Agency (EPA), in November of 1989, included the 200 Areas of the Hanford Site on the National Priority List (NPL) under the Comprehensive Environmental Response, compensation, and Liability Act of 1980 (CERCLA). The 200 Area is divided into operable units based on waste disposal information, location, facility, type, and other characteristics. The 200-BP-1 operable unit is one specific site located within the 200 East Area. Inclusion on the NPL initiated the remedial investigation (RI) process for characterizing the nature and extent of contamination and assessing risks to human health and the environment at the 200-BP-1 operable unit. In March of 1990, a remedial investigation/feasibility study (RI/FS) work plan for the 200-BP-1 operable unit was issued (DOE-RL 1990a). The work plan outlined the first phase of site characterization activities, which were completed in March of 1993 with the issuance of Phase I Remedial Investigation Report for the 200-BP-1 Operable Unit (DOE-RL 1993, Draft A). Remedial action objectives outlined in the RI report suggest that a likely remedial action at the 200-BP-1 operable unit could involve the use of a surface barrier. To further evaluate this technology, additional performance and constructability data are needed to implement this remedial action. This test plan describes the general methodology for conducting a prototype barrier treatability study. The objectives of this treatability study are to determine overall performance and constructability data on an actual waste site in conjunction with the Hanford Site Barrier Development Program.

  1. Characteristics and treatability of oil-bearing wastes from aluminum alloy machining operations.

    PubMed

    Chen, Luke; Hsieh, Chueh-Chen; Wetherbee, John; Yang, Chen-Lu

    2008-04-15

    Enomoto Industry Co., exclusively uses water-based cutting fluids in its aluminum alloy machining operations. Since the cost of disposal can be much greater than the cost of purchase, the treatability of spent cutting fluids is becoming a major criterion for cutting fluid selection. Samples were collected from the machining lines at Enomoto's facility to determine their characteristics and evaluate their treatability with centrifugation, chemical coagulation and electrochemical coagulation. As expected, oil and grease (O&G) and total suspended solids (TSS) are the main reasons that spent cutting fluids are prohibited from being discharged into local swage systems. The average O&G found in the spent cutting fluids is 87,354 mg/L with TSS of more than 70,000 mg/L. Both O&G and TSS are the major contributors to the high turbidity of these waste effluents. A centrifuge with a relative centrifugal force of 1318 x g, was able to reduce 60% of the turbidity. By adding the coagulant aluminum chloride, the oil-water emulsion was destabilized, and the turbidity was reduced from 3249 Formazin Attenuation Units (FAU) to around 314 FAU. With freshly generated aluminum ions in the spent cutting fluid, the electrochemical process destabilized the oil-water emulsion system. The coalesced oil droplets were adsorbed onto the highly dispersed aluminum coagulant. The oil-rich sludge that was generated in the operation was then floated to the surface, forming a blanket that was removed by skimming. The electrochemical treatment was able to reduce the turbidity to less than 14 FAU, which is the detection limit of the Hach DR/4000 UV-vis spectrophotometer. PMID:17850956

  2. TREATABILITY TEST REPORT FOR THE REMOVAL OF CHROMIUM FROM GROUNDWATER AT 100-D AREA USING ELECTROCOAGULATION

    SciTech Connect

    PETERSEN SW

    2009-09-24

    The U.S. Department of Energy (DOE) has committed to accelerate cleanup of contaminated groundwater along the Columbia River. The current treatment approach was driven by a series of Interim Action Records of Decision (IAROD) issued in the mid-1990s. Part of the approach for acceleration involves increasing the rate of groundwater extraction for the chromium plume north of the 100-D Reactor and injecting the treated water in strategic locations to hydraulically direct contaminated groundwater toward the extraction wells. The current treatment system uses ion exchange for Cr(VI) removal, with off-site regeneration of the ion exchange resins. Higher flow rates will increase the cost and frequency of ion exchange resin regeneration; therefore, alternative technologies are being considered for treatment at high flow rates. One of these technologies, electrocoagulation (EC), was evaluated through a pilot-scale treatability test. The primary purpose of the treatability study was to determine the effectiveness of Cr(VI) removal and the robustness/implementability of an EC system. Secondary purposes of the study were to gather information about derivative wastes and to obtain data applicable to scaling the process from the treatability scale to full-scale. The treatability study work plan identified a performance objective and four operational objectives. The performance objective for the treatability study was to determine the efficiency (effectiveness) of hexavalent chromium removal from the groundwater, with a desired concentration of {le} 20 micrograms per liter ({micro}g/L) Cr(VI) in the effluent prior to re-injection. Influent and effluent total chromium and hexavalent chromium data were collected using a field test kit for multiple samples per week, and from off-site laboratory analysis of samples collected approximately monthly. These data met all data quality requirements. Two of three effluent chromium samples analyzed in the off-site (that is, fixed) laboratory

  3. In Vitro Biocompability/Osteogenesis and In Vivo Bone Formation Evalution of Peptide-Decorated Apatite Nanocomposites Assisted via Polydopamine.

    PubMed

    Deng, Yi; Sun, Yuhua; Bai, Yanjie; Gao, Xiang; Zhang, Huan; Xu, Anxiu; Huang, Enyi; Deng, Feng; Wei, Shicheng

    2016-04-01

    Enhancing the biocompatibility and osteogenic activity of nano-apatite for applications in bone graft substitutes and bone tissue engineering have been the current challenge in regeneration of lost bone. Inspired by mussels, here we have developed facile biomimetic approaches for preparation of two types of peptide-conjugated apatite nanocompsoties assisted by polydopamine (pDA). We exploited polydopamine chemistry for the modification of nano-apatite crystals: polydopamine coated apatite (HA-c-pDA) and polydopamine template-mediated apatite (HA-t-pDA), on which bone forming peptide was subsequently immobilized under weakly basic conditions to obtain peptide-conjugated apatite nanocomposites (HA-c-pep and HA-t-pep, respectively). TEM images revealed that HA-c-pDA displayed typically rod-like morphology, while HA-t-pDA was sponge-like structure where pDA sheets were decorated by needle-like apatite crystals with low degree of crystallinity. In the cell culture experiments, HA-t-pep nanocomposite exhibited higher cell proliferation, spreading, and alkaline phosphatase activity as well as calcium nodule-formation, compared with pristine nano-HA and HA-c-pep nanocomposite. We then implanted the peptide-decorated apatite into rabbit calvarial defects and analyzed bone formation after 2 months. The data revealed that HA-t-pep group exhibited remarkably enhanced bioactivity and bone formation in vivo. Based on these results, our biomimetic approach could be a promising tool to develop peptide-conjugated apatites for bone regeneration. Meanwhile, the excellent biocompatibility and high osteogenesis of the peptide-conjugated apatite nanocomposite might confer its great potentials in bone repair, bone augmentation, as well as coating of biomedical implants.

  4. The role of collagen in bone apatite formation in the presence of hydroxyapatite nucleation inhibitors

    PubMed Central

    Nudelman, Fabio; Pieterse, Koen; George, Anne; Bomans, Paul H. H.; Friedrich, Heiner; Brylka, Laura J.; Hilbers, Peter A. J.; de With, Gijsbertus; Sommerdijk, Nico A. J. M.

    2011-01-01

    Bone is a composite material, in which collagen fibrils form a scaffold for a highly organized arrangement of uniaxially oriented apatite crystals1,2. In the periodic 67 nm cross-striated pattern of the collagen fibril3–5, the less dense 40-nm-long gap zone has been implicated as the place where apatite crystals nucleate from an amorphous phase, and subsequently grow6–9. This process is believed to be directed by highly acidic non-collagenous proteins6,7,9–11; however, the role of the collagen matrix12–14 during bone apatite mineralization remains unknown. Here, combining nanometre-scale resolution cryogenic transmission electron microscopy and cryogenic electron tomography15 with molecular modelling, we show that collagen functions in synergy with inhibitors of hydroxyapatite nucleation to actively control mineralization. The positive net charge close to the C-terminal end of the collagen molecules promotes the infiltration of the fibrils with amorphous calcium phosphate (ACP). Furthermore, the clusters of charged amino acids, both in gap and overlap regions, form nucleation sites controlling the conversion of ACP into a parallel array of oriented apatite crystals. We developed a model describing the mechanisms through which the structure, supramolecular assembly and charge distribution of collagen can control mineralization in the presence of inhibitors of hydroxyapatite nucleation. PMID:20972429

  5. Apatite coating of electrospun PLGA fibers using a PVA vehicle system carrying calcium ions.

    PubMed

    Kim, In Ae; Rhee, Sang-Hoon

    2010-01-01

    A novel method to coat electrospun poly(D,L-lactic-co-glycolic acid) (PLGA) fiber surfaces evenly and efficiently with low-crystalline carbonate apatite crystals using a poly(vinyl alcohol) (PVA) vehicle system carrying calcium ions was presented. A non-woven PLGA fabric was prepared by electrospinning: a 10 wt% PLGA solution was prepared using 1,1,3,3-hexafluoro-2-propanol as a solvent and electrospun under a electrical field of 1 kV/cm using a syringe pump with a flowing rate of 3 ml/h. The non-woven PLGA fabric, 12 mm in diameter and 1 mm in thickness, was cut and then coated with a PVA solution containing calcium chloride dihydrate (specimen PPC). As controls, pure non-woven PLGA fabric (specimen P) and fabric coated with a calcium chloride dihydrate solution without PVA (specimen PC) were also prepared. Three specimens were exposed to simulated body fluid for 1 week and this exposure led to form uniform and complete apatite coating layer on the fiber surfaces of specimen PPC. However, no apatite had formed to the fiber surfaces of specimen P and only inhomogeneous coating occurred on the fiber surfaces of specimen PC. These results were explained in terms of the calcium chelating and adhesive properties of PVA vehicle system. The practical implication of the results is that this method provides a simple but efficient technique for coating the fiber surface of an initially non-bioactive material with low-crystalline carbonate apatite.

  6. On the molecular mechanisms of the acid-induced dissociation of hydroxy-apatite in water.

    PubMed

    Hochrein, Oliver; Zahn, Dirk

    2011-06-01

    The enamel/saliva interface is mimicked by the comparably much simpler model of (001) surfaces of hydroxy-apatite ( Ca(10)(PO(4))(6)(OH)(2) ) in contact with aqueous solution. At neutral pH, the dissociation of ions is penalized by more than 150 kJ mol(-1) giving rise to very stable apatite-water interfaces. This picture changes drastically with decreasing pH, as the protonation of phosphate and hydroxide ions lowers the free energy of calcium ions dissociation. Our simulations suggest the mechanism of acid-induced apatite decomposition to i) require a considerable degree of protonation of the apatite surface. The first ion dissociation step ii) involves calcium ions which electrostatic binding has been locally destabilized through phosphate and hydroxide protonation. The depletion of calcium ions embedding the anions then allows iii) the dissociation of the anionic species. Along this line, the protective role of fluoride in caries prevention is related to the stabilization of the calcium triangles embedding the OH(-)/F(-) ions.

  7. Water in the Early Differentiated Asteroids: Insight from Apatite in Basaltic Eucrites

    NASA Astrophysics Data System (ADS)

    Koike, M.; Iizuka, T.; Takahata, N.; Sano, Y.; Haba, M. K.

    2016-08-01

    To understand the water history in early differentiated bodies, we analyze H2O contents and U-Pb ages in apatites from several basaltic eucrites. Our results indicate that at least some part of the Vesta’s crust was anhydrous at 4.5Ga.

  8. Mycorrhizal weathering of apatite as an important calcium source in base-poor forest ecosystems.

    PubMed

    Blum, Joel D; Klaue, Andrea; Nezat, Carmen A; Driscoll, Charles T; Johnson, Chris E; Siccama, Thomas G; Eagar, Christopher; Fahey, Timothy J; Likens, Gene E

    2002-06-13

    The depletion of calcium in forest ecosystems of the northeastern USA is thought to be a consequence of acidic deposition and to be at present restricting the recovery of forest and aquatic systems now that acidic deposition itself is declining. This depletion of calcium has been inferred from studies showing that sources of calcium in forest ecosystems namely, atmospheric deposition and mineral weathering of silicate rocks such as plagioclase, a calcium-sodium silicate do not match calcium outputs observed in forest streams. It is therefore thought that calcium is being lost from exchangeable and organically bound calcium in forest soils. Here we investigate the sources of calcium in the Hubbard Brook experimental forest, through analysis of calcium and strontium abundances and strontium isotope ratios within various soil, vegetation and hydrological pools. We show that the dissolution of apatite (calcium phosphate) represents a source of calcium that is comparable in size to known inputs from atmospheric sources and silicate weathering. Moreover, apatite-derived calcium was utilized largely by ectomycorrhizal tree species, suggesting that mycorrhizae may weather apatite and absorb the released ions directly, without the ions entering the exchangeable soil pool. Therefore, it seems that apatite weathering can compensate for some of the calcium lost from base-poor ecosystems, and should be considered when estimating soil acidification impacts and calcium cycling.

  9. Apatite-mineralized polycaprolactone nanofibrous web as a bone tissue regeneration substrate.

    PubMed

    Yu, Hye-Sun; Jang, Jun-Hyeog; Kim, Tae-Il; Lee, Hae-Hyoung; Kim, Hae-Won

    2009-03-01

    Degradable synthetic polymers with a nanofibrous structure have shown great promise in populating and recruiting cells for the reconstruction of damaged tissues. However, poor cell affinity and lack of bioactivity have limited their potential usefulness in bone regeneration. We produced polymeric nanofiber poly(epsilon-caprolactone) (PCL) with its surface mineralized with bone-like apatite for use as bone regenerative and tissue engineering matrices. PCL was first electrospun into a nanofibrous web, and the surface was further mineralized with apatite following a series of solution treatments. The surface of the mineralized PCL nanofiber was observed to be almost fully covered with nanocrystalline apatites. Through mineralization, the wettability of the nanofiber matrix was greatly improved. Moreover, the murine-derived osteoblastic cells were shown to attach and grow actively on the apatite-mineralized nanofibrous substrate. In particular, the mineralized PCL nanofibrous substrate significantly stimulated the expression of bone-associated genes, including Runx2, collagen type I, alkaline phosphatase, and osteocalcin, when compared with the pure PCL nanofiber substrate without mineralization. The currently developed polymer nanofibrous web with the bioactive mineralized surface is considered to be potentially useful as bone regenerative and tissue engineering matrices.

  10. Quantitative assessment of apatite formation via a biomimetic method using quartz crystal microbalance.

    PubMed

    Tanahashi, M; Kokubo, T; Matsuda, T

    1996-06-01

    Quantitative assessment of hydroxyapatite formation on a gold surface via the biomimetic method, composed of a nucleation step in a simulated body fluid (SBF) containing glass powders and a subsequent apatite growth step in glass powder-free SBF, was made using a quartz crystal microbalance (QCM) technique. The frequency change of the QCM linearly increased with increasing soaking time, and largely depended on the nucleation period. The growth rates, defined as daily increase in thickness, increased monotonicly with an increasing nucleation period of up to 96 h, thereafter being constant at 2.0 microns/day. The growth rate of the apatite layer increased with increasing temperature of the SBF: 0.9, 2.0, and 3.8 microns/day at 25, 37, and 50 degrees C, respectively. The Arrhenius-type activation energy for the growth of apatite was 47.3 kJ/mol. The QCM method was found to be a very powerful tool for quantitative, in situ measurement of precipitation and growth of apatite in real time.

  11. COMPARISON OF APATITE II™ TREATMENT SYSTEM AT TWO MINES FOR METALS REMOVAL

    EPA Science Inventory

    Two abandoned lead-zinc mine sites, the Nevada Stewart Mine (NSM) and Success Mine, are located within the Coeur d'Alene Mining District, in northern Idaho. An Apatite II™ Treatment System (ATS) was implemented at each site to treat metal-laden water, mainly zinc. In the ATS, f...

  12. The role of collagen in bone apatite formation in the presence of hydroxyapatite nucleation inhibitors.

    PubMed

    Nudelman, Fabio; Pieterse, Koen; George, Anne; Bomans, Paul H H; Friedrich, Heiner; Brylka, Laura J; Hilbers, Peter A J; de With, Gijsbertus; Sommerdijk, Nico A J M

    2010-12-01

    Bone is a composite material in which collagen fibrils form a scaffold for a highly organized arrangement of uniaxially oriented apatite crystals. In the periodic 67 nm cross-striated pattern of the collagen fibril, the less dense 40-nm-long gap zone has been implicated as the place where apatite crystals nucleate from an amorphous phase, and subsequently grow. This process is believed to be directed by highly acidic non-collagenous proteins; however, the role of the collagen matrix during bone apatite mineralization remains unknown. Here, combining nanometre-scale resolution cryogenic transmission electron microscopy and cryogenic electron tomography with molecular modelling, we show that collagen functions in synergy with inhibitors of hydroxyapatite nucleation to actively control mineralization. The positive net charge close to the C-terminal end of the collagen molecules promotes the infiltration of the fibrils with amorphous calcium phosphate (ACP). Furthermore, the clusters of charged amino acids, both in gap and overlap regions, form nucleation sites controlling the conversion of ACP into a parallel array of oriented apatite crystals. We developed a model describing the mechanisms through which the structure, supramolecular assembly and charge distribution of collagen can control mineralization in the presence of inhibitors of hydroxyapatite nucleation.

  13. Preparation of fluoride substituted apatite cements as the building blocks for tooth enamel restoration

    NASA Astrophysics Data System (ADS)

    Wei, Jie; Wang, Jiecheng; Liu, Xiaochen; Ma, Jian; Liu, Changsheng; Fang, Jing; Wei, Shicheng

    2011-06-01

    Fluoride substituted apatite cement (fs-AC) was synthesized by using the cement powders of tetracalcium phosphate (TTCP) and sodium fluoride (NaF), and the cement powders were mixed with diluted phosphoric acid (H 3PO 4) as cement liquid to form fs-AC paste. The fs-AC paste could be directly filled into the carious cavities to repair damaged dental enamel. The results indicated that the fs-AC paste was changed into fluorapatite crystals with the atom molar ratio for calcium to phosphorus of 1.66 and the F ion amount of 3 wt% after self-hardening for 2 days. The solubility of fs-AC in Tris-HCl solution (pH 6) was slightly lower than hydroxyapatite cement (HAC) that was similar to the apatite in enamel, indicating the fs-AC was much insensitive to the weakly acidic solution than the apatite in enamel. The fs-AC was tightly combined with the enamel surface because of the chemical reaction between the fs-AC and the apatite in enamel after the caries cavities was filled with fs-AC. The extracts of fs-AC caused no cytotoxicity on L929 cells, which satisfied the relevant criterion on dental biomaterials, revealing good cytocompatibility. The fs-AC had potential prospect for the reconstitution of carious lesion of dental enamel.

  14. Effect of thermal treatment on apatite-forming ability of NaOH-treated tantalum metal.

    PubMed

    Miyazaki, T; Kim, H M; Kokubo, T; Miyaji, F; Kato, H; Nakamura, T

    2001-08-01

    The prerequisite for an artificial material to bond to living bone is the formation of bonelike apatite on its surface in the body. This apatite can be reproduced on its surface even in an acellular simulated body fluid with ion concentrations nearly equal to those of the human blood plasma. The present authors previously showed that the tantalum metal subjected to a NaOH treatment to form a sodium tantalate hydrogel layer on its surface forms the bonelike apatite on its surface in SBF in a short period. The gel layer as-formed on the metal is, however, not resistant against abrasion, and hence thus-treated metal is not useful for clinical applications. In the present study, effects of thermal treatment on the mechanical properties and apatite-forming ability of the NaOH-treated tantalum metal were investigated. The sodium tantalate gel on the NaOH-treated tantalum was dehydrated to convert into amorphous sodium tantalate by a thermal treatment at 300 degrees C in air environment and into crystalline sodium tantalates by the thermal treatment at 500 degrees C. Resistivity of the gel layer against both peeling-off and scratching was significantly improved by the thermal treatment at 300 degrees C. The high apatite-forming ability of the sodium tantalate hydrogel was a little decreased by the thermal treatment at 300 degrees C, but appreciably decreased by the thermal treatment at 500 degrees C. It is believed that the tantalum metal subjected to the 0.5 M-NaOH treatment and the subsequent thermal treatment at 300 degrees C is useful as implants in dental and orthopaedic fields, since it shows high bioactivity as well as high fracture toughness.

  15. The status of strontium in biological apatites: an XANES investigation.

    PubMed

    Bazin, D; Daudon, M; Chappard, Ch; Rehr, J J; Thiaudière, D; Reguer, S

    2011-11-01

    Osteoporosis represents a major public health problem and increases patient morbidity through its association with fragility fractures. Among the different treatments proposed, strontium-based drugs have been shown to increase bone mass in postmenopausal osteoporosis patients and to reduce fracture risk. While the localization of Sr(2+) cations in the bone matrix has been extensively studied, little is known regarding the status of Sr(2+) cations in natural biological apatite. In this investigation the local environment of Sr(2+) cations has been investigated through XANES (X-ray absorption near-edge structure) spectroscopy in a set of pathological and physiological apatites. To assess the localization of Sr(2+) cations in these biological apatites, numerical simulations using the ab initio FEFF9 X-ray spectroscopy program have been performed. The complete set of data show that the XANES part of the absorption spectra may be used as a fingerprint to determine the localization of Sr(2+) cations versus the mineral part of calcifications. More precisely, it appears that a relationship exists between some features present in the XANES part and a Sr(2+)/Ca(2+) substitution process in site (I) of crystal apatite. Regarding the data, further experiments are needed to confirm a possible link between the relationship between the preparation mode of the calcification (cellular activity for physiological calcification and precipitation for the pathological one) and the adsorption mode of Sr(2+) cations (simple adsorption or insertion). Is it possible to draw a line between life and chemistry through the localization of Sr in apatite? The question is open for discussion. A better structural description of these physiological and pathological calcifications will help to develop specific therapies targeting the demineralization process in the case of osteoporosis. PMID:21997917

  16. Isotope dilution analysis of Ca and Zr in apatite and zircon (U-Th)/He chronometry

    NASA Astrophysics Data System (ADS)

    Guenthner, William R.; Reiners, Peter W.; Chowdhury, Uttam

    2016-05-01

    Because radiation damage influences He diffusivity, correlations between (U-Th)/He ages and effective uranium (eU, eU = U + 0.235 × Th) concentrations of single apatite and zircon grains are important for understanding thermal histories. Here we describe a method for quantifying eU concentrations in apatite and zircon grains using isotope dilution ICP-MS measurements of Zr and Ca and stoichiometry of zircon (ZrSiO4) and apatite (Ca5(PO4)3F) to obtain grain masses. Combined with independent U and Th measurements, these yield eU concentrations not based on the traditional morphologic measurements and assumptions. Additional benefits of this method include correct identification of an apatite or zircon and volume estimates for crystal shards. In some cases, this method gives eU concentrations consistent with those calculated with the morphologic approach, but often significant differences are observed between concentrations calculated from the two methods. Differences in eU concentrations for our apatite grains are greater and less than morphology estimates, and the majority are between 0.7 and 31%. With the exception of two grains, all of our zircon grains have differences between 3 and 34% less than morphology estimates. These differences could result from incorrect grain width measurements, mischaracterized grain shape, or incorrect volume calculations of the pure mineral phase due to inclusions. These morphologic errors—combined with evidence for the accuracy of our isotope dilution method from analyses of reference materials—suggest that eU concentrations calculated from morphology may often be significantly inaccurate. Finally, we demonstrate that differences between the two measurements of eU cause age-eU correlation variations for representative thermal histories.

  17. Apatite-forming ability of vinylphosphonic acid-based copolymer in simulated body fluid: effects of phosphate group content.

    PubMed

    Hamai, Ryo; Shirosaki, Yuki; Miyazaki, Toshiki

    2016-10-01

    Phosphate groups on materials surfaces are known to contribute to apatite formation upon exposure of the materials in simulated body fluid and improved affinity of the materials for osteoblast-like cells. Typically, polymers containing phosphate groups are organic matrices consisting of apatite-polymer composites prepared by biomimetic process using simulated body fluid. Ca(2+) incorporation into the polymer accelerates apatite formation in simulated body fluid owing because of increase in the supersaturation degree, with respect to apatite in simulated body fluid, owing to Ca(2+) release from the polymer. However, the effects of phosphate content on the Ca(2+) release and apatite-forming abilities of copolymers in simulated body fluid are rather elusive. In this study, a phosphate-containing copolymer prepared from vinylphosphonic acid, 2-hydroxyethyl methacrylate, and triethylene glycol dimethacrylate was examined. The release of Ca(2+) in Tris-NaCl buffer and simulated body fluid increased as the additive amount of vinylphosphonic acid increased. However, apatite formation was suppressed as the phosphate groups content increased despite the enhanced release of Ca(2+) from the polymer. This phenomenon was reflected by changes in the surface zeta potential. Thus, it was concluded that the apatite-forming ability of vinylphosphonic acid-2-hydroxyethyl methacrylate-triethylene glycol dimethacrylate copolymer treated with CaCl2 solution was governed by surface state rather than Ca(2+) release in simulated body fluid. PMID:27585911

  18. Functions and requirements for a waste dislodging and conveyance system for the Gunite and Associated Tanks Treatability Study at Oak Ridge National Laboratory

    SciTech Connect

    Potter, J.D.; Mullen, O.D.

    1995-09-01

    Functions and requirements for the Waste Dislodging and Conveyance System to be deployed in Gunite and Associated Tanks (GAAT) and tested and evaluated as a candidate tank waste retrieval technology by the GAAT Treatability Study (GAAT TS).

  19. Fluid inclusions in apatite from Jacupiranga calcite carbonatites: Evidence for a fluid-stratified carbonatite magma chamber

    NASA Astrophysics Data System (ADS)

    Costanzo, Alessandra; Moore, Kathryn Ruth; Wall, Frances; Feely, Martin

    2006-10-01

    Carbonatites of the Jacupiranga alkaline-carbonatite complex in São Paulo State, Brazil, were used to investigate mineral-fluid interaction in a carbonatite magma chamber because apatite showed a marked discontinuity between primary fluid inclusion-rich cores and fluid inclusion-poor rims. Sylvite and burbankite, apatite, pyrite, chalcopyrite and ilmenite are the common phases occurring as trapped solids within primary fluid inclusions and reflect the general assemblage of the carbonatite. The apatite cores had higher Sr and REE concentrations than apatite rims, due to the presence of fluid inclusions into which these elements partitioned. A positive cerium anomaly was observed in both the core and rim of apatite crystals because oxidised Ce 4+ partitioned into the magma. The combined evidence from apatite chemistry, fluid inclusion distribution and fluid composition was used to test the hypotheses that the limit of fluid inclusion occurrence within apatite crystals arises from: (1) generation of a separate fluid phase; (2) utilization of all available fluid during the first stage of crystallization; (3) removal of crystals from fluid-rich magma to fluid-poor magma; (4) an increase in the growth rate of apatite; or (5) escape of the fluids from the rim of the apatite after crystallization. The findings are consistent with fractionation and crystal settling of a carbonatite assemblage in a fluid-stratified magma chamber. Secondary fluid inclusions were trapped during a hydrothermal event that precipitated an assemblage of anhedral crystals: strontianite, carbocernaite, barytocalcite, barite and norsethite, pyrophanite, magnesian siderite and baddeleyite, ancylite-(Ce), monazite-(Ce) and allanite. The Sr- and REE-rich nature of the secondary assemblage, and lack of a positive cerium anomaly indicate that hydrothermal fluids have a similar source to the primary magma and are related to a later carbonatite intrusion.

  20. Postmagmatic magnetite-apatite assemblage in mafic intrusions: a case study of dolerite at Olympic Dam, South Australia

    NASA Astrophysics Data System (ADS)

    Apukhtina, Olga B.; Kamenetsky, Vadim S.; Ehrig, Kathy; Kamenetsky, Maya B.; McPhie, Jocelyn; Maas, Roland; Meffre, Sebastien; Goemann, Karsten; Rodemann, Thomas; Cook, Nigel J.; Ciobanu, Cristiana L.

    2016-01-01

    An assemblage of magnetite and apatite is common worldwide in different ore deposit types, including disparate members of the iron-oxide copper-gold (IOCG) clan. The Kiruna-type iron oxide-apatite deposits, a subtype of the IOCG family, are recognized as economic targets as well. A wide range of competing genetic models exists for magnetite-apatite deposits, including magmatic, magmatic-hydrothermal, hydrothermal(-metasomatic), and sedimentary(-exhalative). The sources and mechanisms of transport and deposition of Fe and P remain highly debatable. This study reports petrographic and geochemical features of the magnetite-apatite-rich vein assemblages in the dolerite dykes of the Gairdner Dyke Swarm (~0.82 Ga) that intruded the Roxby Downs Granite (~0.59 Ga), the host of the supergiant Olympic Dam IOCG deposit. These symmetrical, only few mm narrow veins are prevalent in such dykes and comprise besides usually colloform magnetite and prismatic apatite also further minerals (e.g., calcite, quartz). The genetic relationships between the veins and host dolerite are implied based on alteration in the immediate vicinity (~4 mm) of the veins. In particular, Ti-magnetite-ilmenite is partially to completely transformed to titanite and magmatic apatite disappears. We conclude that the mafic dykes were a local source of Fe and P re-concentrated in the magnetite-apatite veins. Uranium-Pb ages for vein apatite and titanite associated with the vein in this case study suggest that alteration of the dolerite and healing of the fractures occurred shortly after dyke emplacement. We propose that in this particular case the origin of the magnetite-apatite assemblage is clearly related to hydrothermal alteration of the host mafic magmatic rocks.

  1. SUMMARY PLAN FOR BENCH-SCALE REFORMER AND PRODUCT TESTING TREATABILITY STUDIES USING HANFORD TANK WASTE

    SciTech Connect

    DUNCAN JB

    2010-08-19

    This paper describes the sample selection, sample preparation, environmental, and regulatory considerations for shipment of Hanford radioactive waste samples for treatability studies of the FBSR process at the Savannah River National Laboratory and the Pacific Northwest National Laboratory. The U.S. Department of Energy (DOE) Hanford tank farms contain approximately 57 million gallons of wastes, most of which originated during the reprocessing of spent nuclear fuel to produce plutonium for defense purposes. DOE intends to pre-treat the tank waste to separate the waste into a high level fraction, that will be vitrified and disposed of in a national repository as high-level waste (HLW), and a low-activity waste (LAW) fraction that will be immobilized for on-site disposal at Hanford. The Hanford Waste Treatment and Immobilization Plant (WTP) is the focal point for the treatment of Hanford tank waste. However, the WTP lacks the capacity to process all of the LAW within the regulatory required timeframe. Consequently, a supplemental LAW immobilization process will be required to immobilize the remainder of the LAW. One promising supplemental technology is Fluidized Bed Steam Reforming (FBSR) to produce a sodium-alumino-silicate (NAS) waste form. The NAS waste form is primarily composed of nepheline (NaAlSiO{sub 4}), sodalite (Nas[AlSiO{sub 4}]{sub 6}Cl{sub 2}), and nosean (Na{sub 8}[AlSiO{sub 4}]{sub 6}SO{sub 4}). Semivolatile anions such as pertechnetate (TcO{sub 4}{sup -}) and volatiles such as iodine as iodide (I{sup -}) are expected to be entrapped within the mineral structures, thereby immobilizing them (Janzen 2008). Results from preliminary performance tests using surrogates, suggests that the release of semivolatile radionuclides {sup 99}Tc and volatile {sup 129}I from granular NAS waste form is limited by Nosean solubility. The predicted release of {sup 99}Tc from the NAS waste form at a 100 meters down gradient well from the Integrated Disposal Facility (IDF

  2. Reduction And Stabilization (Immobilization) Of Pertechnetate To An Immobile Reduced Technetium Species Using Tin(II) Apatite

    SciTech Connect

    Duncan, J. B.

    2012-11-02

    Synthetic tin(II)apatite reduces pertechnetate from the mobile +7 to a non-mobile oxidation state and sequesters the technetium, preventing re-oxidization to mobile +7 state under acidic or oxygenated conditions. Previous work indicated technetium reacted Sn(II)apatite can achieve an ANSI leachability index of 12.8 in Cast Stone. An effect by pH is observed on the distribution coefficient, the highest distribution coefficient being l70,900 observed at pH levels of 2.5 to 10.2. The tin apatite was resistant to releasing technetium under test conditions.

  3. TREATABILITY TEST FOR REMOVING TECHNETIUM-99 FROM 200-ZP-1 GROUNDWATER HANFORD SITE

    SciTech Connect

    PETERSEN SW; TORTOSO AC; ELLIOTT WS; BYRNES ME

    2007-11-29

    The 200-ZP-1 Groundwater Operable Unit (OU) is one of two groundwater OUs located within the 200 West groundwater aggregate area of the Hanford Site. The primary risk-driving contaminants within the 200-ZP-1 OU include carbon tetrachloride and technetium-99 (Tc-99). A pump-and-treat system for this OU was initially installed in 1995 to control the 0.002 kg/m{sup 3} (2000 {micro}g/L) contour of the carbon tetrachloride plume. Carbon tetrachloride is removed from groundwater with the assistance of an air-stripping tower. Ten extraction wells and three injection wells operate at a combined rate of approximately 0.017m{sup 3}/s (17.03 L/s). In 2005, groundwater from two of the extraction wells (299-W15-765 and 299-W15-44) began to show concentrations greater than twice the maximum contaminant level (MCL) of Tc-99 (33,309 beq/m{sup 3} or 900 pCi/L). The Tc-99 groundwater concentrations from all ten of the extraction wells when mixed were more than one-half of the MCL and were slowly increasing. If concentrations continued to rise and the water remained untreated for Tc-99, there was concern that the water re-injected into the aquifer could exceed the MCL standard. Multiple treatment technologies were reviewed for selectively removing Tc-99 from the groundwater. Of the treatment technologies, only ion exchange was determined to be highly selective, commercially available, and relatively low in cost. Through research funded by the U.S. Department of Energy, the ion-exchange resin Purolite{reg_sign} A-530E was found to successfully remove Tc-99 from groundwater, even in the presence of competing anions. For this and other reasons, Purolite{reg_sign} A-530E ion exchange resin was selected for treatability testing. The treatability test required installing resin columns on the discharge lines from extraction wells 299-W15-765 and 299-W15-44. Preliminary test results have concluded that the Purolite{reg_sign} A-530E resin is effective at removing Tc-99 from groundwater to

  4. Treatability Test for Removing Technetium-99 from 200-ZP-1 Groundwater, Hanford Site

    SciTech Connect

    Byrnes, M.E.; Petersen, S.W.; Tortoso, A.; Elliott, W.S.

    2008-07-01

    The 200-ZP-1 Groundwater Operable Unit (OU) is one of two groundwater OUs located within the 200 West groundwater aggregate area of the Hanford Site. The primary risk-driving contaminants within the 200-ZP-1 OU include carbon tetrachloride and technetium-99 (Tc-99). A pump-and-treat system for this OU was initially installed in 1995 to control the 0.002 kg /m{sup 3} (2000 {mu}g/L) contour of the carbon tetrachloride plume. Carbon tetrachloride is removed from groundwater with the assistance of an air-stripping tower. Ten extraction wells and three injection wells operate at a combined rate of approximately 0.017m{sup 3}/s (17.03 L/s). In 2005, groundwater from two of the extraction wells (299-W15-765 and 299-W15-44) began to show concentrations greater than twice the maximum contaminant level (MCL) of Tc-99 (33,309 beq/m{sup 3} or 900 pCi/L). The Tc-99 groundwater concentrations from all ten of the extraction wells when mixed were more than one-half of the MCL and were slowly increasing. If concentrations continued to rise and the water remained untreated for Tc-99, there was concern that the water re-injected into the aquifer could exceed the MCL standard. Multiple treatment technologies were reviewed for selectively removing Tc-99 from the groundwater. Of the treatment technologies, only ion exchange was determined to be highly selective, commercially available, and relatively low in cost. Through research funded by the U.S. Department of Energy, the ion-exchange resin Purolite{sup R} A-530E1 was found to successfully remove Tc-99 from groundwater, even in the presence of competing anions. For this and other reasons, Purolite{sup R} A-530E ion exchange resin was selected for treatability testing. The treatability test required installing resin columns on the discharge lines from extraction wells 299-W15-765 and 299-W15-44. Preliminary test results have concluded that the Purolite{sup R} A-530E1 resin is effective at removing Tc-99 from groundwater to below

  5. The kinetics of the ordering of 13C-18O bonds in calcite and apatite

    NASA Astrophysics Data System (ADS)

    Stolper, D. A.; Halevy, I.; Eiler, J. M.

    2011-12-01

    Eiler and Schauble (2004) showed that the isotopes of C and O are not randomly distributed within single phases such as CO2 gas and carbonates, and in particular, that heavy isotopes of C and O tend to bond preferentially (clump) at lower temperatures. Consequently, the measurement of the deviation from a random distribution of C and O isotope distributions in a single phase can be used as a thermometer. As with other geothermometers based on homogeneous or heterogeneous equilibria, the clumped-isotope thermometer is susceptible to resetting (e.g., if the phase is reheated or experiences slow cooling). Thus, clumped-isotope "temperatures" of phases that have experienced complex thermal histories may, in fact, be closure temperatures, the interpretation of which requires quantification of the kinetics of redistribution of C and O isotopes as a function of temperature. These kinetics have received increasing attention (Dennis and Schrag, 2010; Passey 2010), and are likely to be critical for understanding clumped-isotope temperatures of samples that have been buried for long periods of time. To better constrain these kinetics we performed experiments on natural optical calcite from Mexico and carbonate-bearing apatite from the Siilinjarvi carbonatite (Finland). For each experiment, multiple single crystal grains (~2 mm in diameter) of calcite or apatite were loaded in open Pt capsules, pressurized with Ar gas, and held at 400-700 °C, 550 bars using a rapid quench TZM apparatus for 5 min to 520 hrs. After quenching, 13C-18O clumping was measured in the samples; the change from the initial Δ47 with time for each phase at each temperature was fit to simple mechanistic models of isotope exchange between sites in these phases. One conclusion of the experimental study is that resetting the internal ordering of carbonate groups proceeds more rapidly in calcites than in apatites. For example, heating apatite at 400 °C results in no change in clumping over a 24 hr period

  6. Stable isotope record of coexisting apatite and dolomite in Early Cambrian phosphorites, Meishucun section, South China

    NASA Astrophysics Data System (ADS)

    Wegwerth, Antje; Struck, Ulrich; Segl, Monika; Vennemann, Torsten W.; Gehlken, Peer-L.; Heubeck, Christoph; Böttcher, Michael E.

    2010-05-01

    The Precambrian-Cambrian transition forms one of the most dramatic time periods in Earth's history, as global changes in tectonics, climate and chemistry in the atmosphere and oceans favoured the worldwide Cambrian Radiation and a concomitant ecosphere revolution. This time interval is paralleled by the first appearance of the widespread giant phosphorites. The well-known Meishucun section (South China), a former candidate section for the Pc-C boundary, documents phosphorite genesis amongst a rapid biodiversification, immediately following the end of the Precambrian in a low-latitude, shallow-water carbonate shelf. This contribution aims to elucidate the relation between simultaneous phosphorite deposition and global environmental conditions at the Pc-C boundary by using stable carbon and oxygen isotope analyses. Accurate determinations of d13C and d18O values may allow conclusions about ancient ocean circulation, paleo-productivity, paleo-temperatures, and most prominently diagenetic processes. The investigated samples from the Meishucun section basically consist of apatite, dolomite, and quartz that may be further devided into a lower and upper phosphorite as well as an overlying dolostone intervall. Additionally, calcite and siderite occur as minor compounds in some samples. Bulk d13C values of the carbonate fraction correlate with dolomite abundance throughout the section ranging from -4 to 1 per mil. Furthermore, several horizons suggest a relation between d13C values and apatite content, implying lower d13C values in apatites compared to coexisting dolomite. A slight negative d13C excursion at the top of the lower phosphorite coincides with the first appearance of small shelly fossils. Corresponding bulk d18O values generally show a stratigraphic-upward trend towards lower values throughout the record with slightly higher values in dolomite-rich sections. This may either indicate a warming trend during deposition, an isotopic shift in sea water composition

  7. New insights on He diffusion in apatite and implication for (U-Th)/He thermochronology (Invited)

    NASA Astrophysics Data System (ADS)

    Gautheron, C.; Tassan-Got, L.; Gerin, C.; Mbongo, D.; Roques, J.; Oliviero, E.; Bachelet, C.; Simoni, E.

    2013-12-01

    The apatite (U-Th)/He (AHe) system has rapidly become a very popular thermochronometer to constrain exhumation and relief evolution in a variety of geological contexts, as it allows dating and estimating the amount of denudation. However, the interpretation of AHe data depends on a precise knowledge of He diffusion in apatite, which is sensible in the 55 to 120°C range. Several studies suggest that radiation damage generated by U and Th decay can create traps for He atoms, increasing He retention as a function of the number of traps. The radiation damage also anneals with temperature and the amount of damage in an apatite crystal will be a balance between production and annealing, controlled by U-Th concentration, grain chemistry and thermal history (Shuster et al., 2006; Flowers et al., 2009; Gautheron et al., 2009; 2013). However these models are not well constrained and do not fully explain the mechanism of He retention. In order to have a deeper insight on this issue, multidisciplinary studies on apatite combining diffusion experiments by Elastic Recoil Diffusion Analysis (ERDA) with diffusion calculation Density Functional Theory (DFT) were performed. ERDA experiments were conducted on different macro-crystals, and we probed the shape of a He profile implanted into a planar and polished surface of the crystal. The helium profile evolves with temperature and allows the quantification of He diffusivity. Additionally, DFT calculations of a crystal of apatite have been run to find the favored paths of a helium atom between interstitial sites, leading to a computation of the activation energy and the diffusion coefficient. Crystals with different F and Cl compositions, in similar proportion as natural ones, have been investigated and show chemical variations due to steric effects. Using ERDA and DFT approaches, we demonstrate that in addition to the damage, the grain chemistry strongly impacts He diffusivity and needs to be taken into account. Shuster, D., Flowers

  8. Deep Vadose Zone Treatability Test for the Hanford Central Plateau. Interim Post-Desiccation Monitoring Results, Fiscal Year 2015

    SciTech Connect

    Truex, Michael J.; Strickland, Christopher E.; Oostrom, Martinus; Johnson, Christian D.; Tartakovsky, Guzel D.; Johnson, Timothy C.; Clayton, Ray E.; Chronister, Glen B.

    2015-09-01

    A field test of desiccation is being conducted as an element of the Deep Vadose Zone Treatability Test Program. The active desiccation portion of the test has been completed. Monitoring data have been collected at the field test site during the post-desiccation period and are reported herein. This is an interim data summary report that includes about 4 years of post-desiccation monitoring data. The DOE field test plan proscribes a total of 5 years of post-desiccation monitoring.

  9. Hydraulic testing plan for the Bear Creek Valley Treatability Study, Oak Ridge Y-12 Plant, Oak Ridge, Tennessee

    SciTech Connect

    1997-09-01

    The Bear Creek Valley (BCV) Treatability Study is intended to provide site-specific data defining potential treatability technologies applicable to contaminated groundwater and surface water. The ultimate goal of this effort is to install a treatment system that will remove uranium, technetium, nitrate, and several metals from groundwater before it reaches Bear Creek. This project directly supports the BCV Feasibility Study. Part of the Treatability Study, Phase II Hydraulic Performance Testing, will produce hydraulic and treatment performance data required to design a long-term treatment system. This effort consists of the installation and testing of two groundwater collection systems: a trench in the vicinity of GW-835 and an angled pumping well adjacent to NT-1. Pumping tests and evaluations of gradients under ambient conditions will provide data for full-scale design of treatment systems. In addition to hydraulic performance, in situ treatment chemistry data will be obtained from monitoring wells installed in the reactive media section of the trench. The in situ treatment work is not part of this test plan. This Hydraulic Testing Plan describes the location and installation of the trench and NT-1 wells, the locations and purpose of the monitoring wells, and the procedures for the pumping tests of the trench and NT-1 wells.

  10. 4He Implantation in Natural Diamond: Implications for Apatite (U-Th)/He Thermochronometry

    NASA Astrophysics Data System (ADS)

    Phillips, D.; Kohn, B. P.; Gleadow, A. J.; Harris, J. W.

    2007-12-01

    Current apatite (U-Th)/He thermochronometry protocols correct for ejection of α-particles from grain margins. However, the potential for implantation of 4He into apatite grains, from primary or secondary actinide minerals, has received more limited attention. Evidence for significant natural α-fluxes in the near- surface environment is provided by surface feature and He abundance studies on diamond. Intense α- damage induces a green colour centre in diamond, enabling visual assessment of natural α-implantation doses. Diamonds with transparent green coats and/or green spots occur in most primary and detrital diamond deposits worldwide, indicating that α-implantation rates into upper crustal minerals may be more significant than previously envisaged. Experiments on transparent green-coated natural diamonds reveal implanted αHe concentrations up to 0.015 cc/g, attributed to secondary uranium phases deposited by circulating groundwater (Shelkov et al., 1998). Implantation of similar α-dosages into apatite grains would increase (U-Th)/He ages by up to several hundred percent, dependent on α-dose rate, grain dimensions and actinide content. Investigation of actinide-rich granites in Australia has revealed the common juxtaposition of apatite and actinide phases such as monazite and zircon. In addition, secondary actinide-bearing phases (e.g. uraninite) are observed along joints, fractures, miarolitic cavities and weathering fronts, thus providing additional α-sources. These results demonstrate that (U-Th)/He thermochronometry analyses of apatite, particularly from actinide-rich, weathered granites and sediments, need to evaluate the potential for 4He implantation in the near-surface environment. Insight into the extent of this problem may be achievable through multiple analyses of single grains, in situ laser probe analyses, 4He/3He step-heating experiments, abrasion of grains and/or complementary apatite fission track analyses. Reference: Shelkov, D

  11. Treatability study of Tank E-3-1 waste: mixed waste stream SR-W049

    SciTech Connect

    Langton, C.A.

    1997-08-21

    Treatability studies were conducted for tank E-3-1 waste which was previously characterized in WSRC-RP-87-0078. The waste was determined to be mixed waste because it displayed the characteristic of metal toxicity for Hg and Cr and was also contaminated with low levels of radionuclides. Two types of treatments for qualifying this waste suitable for land disposal were evaluated: ion exchange and stabilization with hydraulic materials (portland cement, slag and magnesium phosphate cement). These treatments were selected for testing because: (1) Both treatments can be carried out as in-drum processes., (2) Cement stabilization is the RCRA/LDR best developed available technology (BDAT) for Hg (less than 280 mg/L) and for Cr., and (3) Ion exchange via Mag-Sep is a promising alternative technology for in drum treatment of liquid wastes displaying metal toxicity. Cement stabilization of the E-3-1 material ( supernate and settled solids) resulted in waste forms which passed the TCLP test for both Hg and Cr. However, the ion exchange resins tested were ineffective in removing the Hg from this waste stream. Consequently, cement stabilization is recommended for a treatment of the five drums of the actual waste.

  12. Treatability study for the bench-scale solidification of nonincinerable LDR low-level mixed waste

    SciTech Connect

    Gering, K.L.

    1993-01-01

    The focus of this report is the solidification of nonincinerable, land disposal restricted (LDR) low-level mixed waste generated at the Idaho National Engineering Laboratory. Benchscale solidification was performed on samples of this mixed waste, which was done under a Resource Conservation and Recovery Act treatability study. Waste forms included liquids, sludges, and solids, and treatment techniques included the use of conventional Portland cement and sulphur polymer cement (SPC). A total of 113 monoliths were made under the experimental design matrix for this study; 8 of these were ``blank`` monoliths (contained no waste). Thus, 105 monoliths were used to solidify 21.6 kg of mixed waste; 92 were made with Portland cement systems, and 13 were made with SPC. Recipes for all monoliths are given, and suggested recipes (as based on the minimized leaching of toxic components) are summarized. In most cases, the results presented herein indicate that solidification was successful in immobilizing toxic metals, thereby transforming low-level mixed waste into low-level nonhazardous waste. The ultimate goal of this project is to use appropriate solidification techniques, as described in the literature, to transform low-level mixed waste to low-level nonhazardous waste by satisfying pertinent disposal requirements for this waste. Disposal requirements consider the toxicity characteristic leaching procedure tests, a free liquids test, and radiological analyses. This work is meaningful in that it will provide a basis for the disposal of waste that is currently categorized as LDR low-level mixed waste.

  13. Treatability study for the bench-scale solidification of nonincinerable LDR low-level mixed waste

    SciTech Connect

    Gering, K. L.

    1993-01-01

    The focus of this report is the solidification of nonincinerable, land disposal restricted (LDR) low-level mixed waste generated at the Idaho National Engineering Laboratory. Benchscale solidification was performed on samples of this mixed waste, which was done under a Resource Conservation and Recovery Act treatability study. Waste forms included liquids, sludges, and solids, and treatment techniques included the use of conventional Portland cement and sulphur polymer cement (SPC). A total of 113 monoliths were made under the experimental design matrix for this study; 8 of these were blank'' monoliths (contained no waste). Thus, 105 monoliths were used to solidify 21.6 kg of mixed waste; 92 were made with Portland cement systems, and 13 were made with SPC. Recipes for all monoliths are given, and suggested recipes (as based on the minimized leaching of toxic components) are summarized. In most cases, the results presented herein indicate that solidification was successful in immobilizing toxic metals, thereby transforming low-level mixed waste into low-level nonhazardous waste. The ultimate goal of this project is to use appropriate solidification techniques, as described in the literature, to transform low-level mixed waste to low-level nonhazardous waste by satisfying pertinent disposal requirements for this waste. Disposal requirements consider the toxicity characteristic leaching procedure tests, a free liquids test, and radiological analyses. This work is meaningful in that it will provide a basis for the disposal of waste that is currently categorized as LDR low-level mixed waste.

  14. Potentially Treatable Disorder Diagnosed Post Mortem by Exome Analysis in a Boy with Respiratory Distress.

    PubMed

    Imperatore, Valentina; Mencarelli, Maria Antonietta; Fallerini, Chiara; Bianciardi, Laura; Ariani, Francesca; Furini, Simone; Renieri, Alessandra; Mari, Francesca; Frullanti, Elisa

    2016-02-27

    We highlight the importance of exome sequencing in solving a clinical case of a child who died at 14 months after a series of respiratory crises. He was the half-brother of a girl diagnosed at 7 years with the early-onset seizure variant of Rett syndrome due to CDKL5 mutation. We performed a test for CDKL5 in the boy, which came back negative. Driven by the mother's compelling need for a diagnosis, we moved forward performing whole exome sequencing analysis. Surprisingly, two missense mutations in compound heterozygosity were identified in the RAPSN gene encoding a receptor-associated protein with a key role in clustering and anchoring nicotinic acetylcholine receptors at synaptic sites. This gene is responsible for a congenital form of myasthenic syndrome, a disease potentially treatable with cholinesterase inhibitors. Therefore, an earlier diagnosis in this boy would have led to a better clinical management and prognosis. Our study supports the key role of exome sequencing in achieving a definite diagnosis in severe perinatal diseases, an essential step especially when a specific therapy is available.

  15. Treatability studies of actual listed waste sludges from the Oak Ridge Reservation (ORR)

    SciTech Connect

    Jantzen, C.M.; Peeler, D.K.; Gilliam, T.M.; Bleier, A.; Spence, R.D.

    1996-05-06

    Oak Ridge National Laboratory (ORNL) and Savannah River Technology Center (SRTC) are investigating vitrification for various low-level and mixed wastes on the Oak Ridge Reservation (ORR). Treatability studies have included surrogate waste formulations at the laboratory-, pilot-, and field-scales and actual waste testing at the laboratory- and pilot-scales. The initial waste to be processing through SRTC`s Transportable Vitrification System (TVS) is the K-1407-B and K-1407-C (B/C) Pond sludge waste which is a RCRA F-listed waste. The B/C ponds at the ORR K-25 site were used as holding and settling ponds for various waste water treatment streams. Laboratory-, pilot-, and field- scale ``proof-of-principle`` demonstrations are providing needed operating parameters for the planned field-scale demonstration with actual B/C Pond sludge waste at ORR. This report discusses the applied systems approach to optimize glass compositions for this particular waste stream through laboratory-, pilot-, and field-scale studies with surrogate and actual B/C waste. These glass compositions will maximize glass durability and waste loading while optimizing melt properties which affect melter operation, such as melt viscosity and melter refractory corrosion. Maximum waste loadings minimize storage volume of the final waste form translating into considerable cost savings.

  16. Treatability test of a stacked-tray air stripper for VOC in water

    SciTech Connect

    Pico, T., LLNL

    1998-04-01

    A common strategy for hydraulic containment and mass removal at VOC contaminated sites is `pump and treat (P&T)`. In P&T operations, contaminated ground water is pumped from wells, treated above ground, and discharged. Many P&T remediation systems at VOC sites rely on air stripping technology because VOCs are easily transferred to the vapor phase. In stacked-tray air strippers, contaminated water is aerated while it flows down through a series of trays. System operations at LLNL are strictly regulated by the California and federal Environmental Protection Agencies (Cal/EPA and EPA), the Bay Area Air Quality Management District (BAAQMD), the California Regional Water Quality Control Board (RWQCB) and the Department of Toxic Substances Control (DTSC). These agencies set discharge limits, require performance monitoring, and assess penalties for non-compliance. National laboratories are also subject to scrutiny by the public and other government agencies. This extensive oversight makes it necessary to accurately predict field treatment performance at new extraction locations to ensure compliance with all requirements prior to facility activation. This paper presents treatability test results for a stacked- tray air stripper conducted at LLNL and compares them to the vendor`s modeling software results.

  17. Treatability study of absorbent polymer waste form for mixed waste treatment

    SciTech Connect

    Herrmann, S. D.; Lehto, M. A.; Stewart, N. A.; Croft, A. D.; Kern, P. W.

    2000-02-10

    A treatability study was performed to develop and characterize an absorbent polymer waste form for application to low level (LLW) and mixed low level (MLLW) aqueous wastes at Argonne National Laboratory-West (ANL-W). In this study absorbent polymers proved effective at immobilizing aqueous liquid wastes in order to meet Land Disposal Restrictions for subsurface waste disposal. Treatment of aqueous waste with absorbent polymers provides an alternative to liquid waste solidification via high-shear mixing with clays and cements. Significant advantages of absorbent polymer use over clays and cements include ease of operations and waste volume minimization. Absorbent polymers do not require high-shear mixing as do clays and cements. Granulated absorbent polymer is poured into aqueous solutions and forms a gel which passes the paint filter test as a non-liquid. Pouring versus mixing of a solidification agent not only eliminates the need for a mixing station, but also lessens exposure to personnel and the potential for spread of contamination from treatment of radioactive wastes. Waste minimization is achieved as significantly less mass addition and volume increase is required of and results from absorbent polymer use than that of clays and cements. Operational ease and waste minimization translate into overall cost savings for LLW and MLLW treatment.

  18. Screening tests for assessing treatability of inorganic industrial wastes by stabilisation/solidification with cement.

    PubMed

    Stegemann, J A; Zhou, Q

    2009-01-15

    Stabilisation/solidification with cementitious or pozzolanic binders (S/S) is an option for reducing leachability of contaminants from residual, predominantly inorganic, industrial wastes and contaminated soils before disposal or reuse. Treatment by S/S is complicated by the fact that the presence of impurities, such as the contaminants and bulk matrix components present in industrial wastes, can have deleterious effects on cements. Therefore, careful laboratory development and testing of S/S formulations are required prior to full-scale application, to avoid technology failures, including problems with handling and contaminant retention. An understanding of cement chemistry and contaminant immobilisation mechanisms has been used to propose a series of test methods and performance thresholds for use in efficient evaluation of the treatability of industrial wastes by S/S, and optimising S/S formulations: measurement of stabilised/solidified product workability, bleeding and setting time (for flowable mixtures) or Proctor compaction (for compactable mixtures), together with unconfined compressive strength, leachability in a batch extraction with distilled water, and hydraulic conductivity.

  19. Validation of an algorithm to determine the primary care treatability of emergency department visits

    PubMed Central

    Jeffery, Molly Moore; Bellolio, M Fernanda; Wolfson, Julian; Abraham, Jean M; Dowd, Bryan E; Kane, Robert L

    2016-01-01

    Objectives We propose a new claims-computable measure of the primary care treatability of emergency department (ED) visits and validate it using a nationally representative sample of Medicare data. Study design and setting This is a validation study using 2011–2012 Medicare claims data for a nationally representative 5% sample of fee-for-service beneficiaries to compare the new measure's performance to the Ballard variant of the Billings algorithm in predicting hospitalisation and death following an ED visit. Outcomes Hospitalisation within 1 day or 1 week of an ED visit; death within 1 week or 1 month of an ED visit. Results The Minnesota algorithm is a strong predictor of hospitalisations and deaths, with performance similar to or better than the most commonly used existing algorithm to assess the severity of ED visits. The Billings/Ballard algorithm is a better predictor of death within 1 week of an ED visit; this finding is entirely driven by a small number of ED visits where patients appear to have been dead on arrival. Conclusions The procedure-based approach of the Minnesota algorithm allows researchers to use the clinical judgement of the ED physician, who saw the patient to determine the likely severity of each visit. The Minnesota algorithm may thus provide a useful tool for investigating ED use in Medicare beneficiaries. PMID:27566637

  20. Potentially Treatable Disorder Diagnosed Post Mortem by Exome Analysis in a Boy with Respiratory Distress

    PubMed Central

    Imperatore, Valentina; Mencarelli, Maria Antonietta; Fallerini, Chiara; Bianciardi, Laura; Ariani, Francesca; Furini, Simone; Renieri, Alessandra; Mari, Francesca; Frullanti, Elisa

    2016-01-01

    We highlight the importance of exome sequencing in solving a clinical case of a child who died at 14 months after a series of respiratory crises. He was the half-brother of a girl diagnosed at 7 years with the early-onset seizure variant of Rett syndrome due to CDKL5 mutation. We performed a test for CDKL5 in the boy, which came back negative. Driven by the mother’s compelling need for a diagnosis, we moved forward performing whole exome sequencing analysis. Surprisingly, two missense mutations in compound heterozygosity were identified in the RAPSN gene encoding a receptor-associated protein with a key role in clustering and anchoring nicotinic acetylcholine receptors at synaptic sites. This gene is responsible for a congenital form of myasthenic syndrome, a disease potentially treatable with cholinesterase inhibitors. Therefore, an earlier diagnosis in this boy would have led to a better clinical management and prognosis. Our study supports the key role of exome sequencing in achieving a definite diagnosis in severe perinatal diseases, an essential step especially when a specific therapy is available. PMID:26927095

  1. LABORATORY REPORT ON THE REDUCTION AND STABILIZATION (IMMOBILIZATION) OF PERTECHNETATE TO TECHNETIUM DIOXIDE USING TIN(II)APATITE

    SciTech Connect

    DUNCAN JB; HAGERTY K; MOORE WP; RHODES RN; JOHNSON JM; MOORE RC

    2012-06-01

    This effort is part of the technetium management initiative and provides data for the handling and disposition of technetium. To that end, the objective of this effort was to challenge tin(II)apatite (Sn(II)apatite) against double-shell tank 241-AN-105 simulant spiked with pertechnetate (TcO{sub 4}{sup -}). The Sn(II)apatite used in this effort was synthesized on site using a recipe developed at and provided by Sandia National Laboratories; the synthesis provides a high quality product while requiring minimal laboratory effort. The Sn(II)apatite reduces pertechnetate from the mobile +7 oxidation state to the non-mobile +4 oxidation state. It also sequesters the technetium and does not allow for re-oxidization to the mo bile +7 state under acidic or oxygenated conditions within the tested period oftime (6 weeks). Previous work (RPP-RPT-39195, Assessment of Technetium Leachability in Cement-Stabilized Basin 43 Groundwater Brine) indicated that the Sn(II)apatite can achieve an ANSI leachability index in Cast Stone of 12.8. The technetium distribution coefficient for Sn(II)apatite exhibits a direct correlation with the pH of the contaminated media. Table A shows Sn(II)apatite distribution coefficients as a function of pH. The asterisked numbers indicate that the lower detection limit of the analytical instrument was used to calculate the distribution coefficient as the concentration of technetium left in solution was less than the detection limit. The loaded sample (200 mg of Sn(II)apatite loaded with O.311 mg of Tc-99) was subjected to different molarities of nitric acid to determine if the Sn(II)apatite would release the sequestered technetium. The acid was allowed to contact for 1 minute with gentle shaking ('1st wash'); the aqueous solution was then filtered, and the filtrate was analyzed for Tc-99. Table B shows the results ofthe nitric acid exposure. Another portion of acid was added, shaken for a minute, and filtered ('2nd wash'). The technetium-loaded Sn(II)apatite

  2. A temporal record of pre-eruptive magmatic volatile contents at Campi Flegrei: Insights from texturally-constrained apatite analyses

    NASA Astrophysics Data System (ADS)

    Stock, Michael J.; Isaia, Roberto; Humphreys, Madeleine C. S.; Smith, Victoria C.; Pyle, David M.

    2016-04-01

    Apatite is capable of incorporating all major magmatic volatile species (H2O, CO2, S, Cl and F) into its crystal structure. Analysis of apatite volatile contents can be related to parental magma compositions through the application of pressure and temperature-dependent exchange reactions (Piccoli and Candela, 1994). Once included within phenocrysts, apatite inclusions are isolated from the melt and preserve a temporal record of magmatic volatile contents in the build-up to eruption. In this work, we measured the volatile compositions of apatite inclusions, apatite microphenocrysts and pyroxene-hosted melt inclusions from the Astroni 1 eruption of Campi Flegrei, Italy (Stock et al. 2016). These data are coupled with magmatic differentiation models (Gualda et al., 2012), experimental volatile solubility data (Webster et al., 2014) and thermodynamic models of apatite compositional variations (Piccoli and Candela, 1994) to decipher pre-eruptive magmatic processes. We find that apatite halogen/OH ratios decreased through magmatic differentiation, while melt inclusion F and Cl concentrations increased. Melt inclusion H2O contents are constant at ~2.5 wt%. These data are best explained by volatile-undersaturated differentiation over most of the crystallisation history of the Astroni 1 melt, with melt inclusion H2O contents reset at shallow levels during ascent. Given the high diffusivity of volatiles in apatite (Brenan, 1993), the preservation of volatile-undersaturated melt compositions in microphenocrysts suggests that saturation was only achieved 10 - 103 days before eruption. We suggest that late-stage transition into a volatile-saturated state caused an increase in magma chamber overpressure, which ultimately triggered the Astroni 1 eruption. This has major implications for monitoring of Campi Flegrei and other similar volcanic systems. Piccoli and Candela, 1994. Am. J. of Sc., 294, 92-135. Stock et al., 2016, Nat. Geosci. Gualda et al., 2012. J. Pet., 53, 875

  3. Electrospun Nanostructured Fibers of Collagen-Biomimetic Apatite on Titanium Alloy

    PubMed Central

    Iafisco, Michele; Foltran, Ismaela; Sabbatini, Simona; Tosi, Giorgio; Roveri, Norberto

    2012-01-01

    Titanium and its alloys are currently the mainly used materials to manufacture orthopaedic implants due to their excellent mechanical properties and corrosion resistance. Although these materials are bioinert, the improvement of biological properties (e.g., bone implant contact) can be obtained by the application of a material that mimics the bone extracellular matrix. To this aim, this work describes a new method to produce nanostructured collagen-apatite composites on titanium alloy substrate, by combining electrospinning and biomimetic mineralization. The characterization results showed that the obtained mineralized scaffolds have morphological, structural, and chemical compositional features similar to natural bone extracellular matrix. Finally, the topographic distribution of the chemical composition in the mineralized matrix evaluated by Fourier Transform Infrared microspectroscopy demonstrated that the apatite nanocrystals cover the collagen fibers assembled by the electrospinning. PMID:22400013

  4. Characterization of hydroxyapatite and carbonated apatite by photo acoustic FTIR spectroscopy.

    PubMed

    Rehman, I; Bonfield, W

    1997-01-01

    An understanding of the interfacial relationship between a bioceramic implant and the adjacent bone tissue is facilitated by precise characterization of the associated structures. The structure of different commercial synthetic hydroxyapatite powders and a novel carbonated apatite have been studied with photo-acoustic (PAS) Fourier transform infrared (FTIR) spectroscopy. The PAS technique is an ideal method for analysing biomaterials, as materials can be analysed without the need to reduce the particle size or to dilute with KBr. Spectra from carbonated apatite appear to be different from those of commercial hydroxyapatite powders, with the main difference lying in the carbonate and phosphate ratio. Commercial hydroxyapatite powders from different sources have also been analysed and compared.

  5. Incorporation of uranium into a biomimetic apatite: physicochemical and biological aspects.

    PubMed

    Chatelain, Grégory; Bourgeois, Damien; Ravaux, Johann; Averseng, Olivier; Vidaud, Claude; Meyer, Daniel

    2015-04-01

    Bone is the main target organ for the storage of several toxic metals, including uranium. But the mode of action of uranium on bones remains poorly understood. To better assess the impact of uranium on bone cells, synthetic biomimetic apatites encompassing a controlled amount of uranium were prepared and analyzed. This study revealed the physicochemical impact of uranium on apatite mineralization: the presence of the metal induces a loss of crystallinity and a lower mineralization rate. The prepared samples were then used as substrates for bone cell culture. Osteoblasts were not sensitive to the presence of uranium in the support, whereas previous results showed a deleterious effect of uranium introduced into a cell culture solution. This work should therefore have some original prospects within the context of toxicological studies concerning the effect of metallic cations on bone cell systems.

  6. Sulfur evolution of oxidized arc magmas as recorded in apatite from a porphyry copper batholith

    NASA Astrophysics Data System (ADS)

    Streck, Martin J.; Dilles, John H.

    1998-06-01

    Uniformly sulfur-rich cores abruptly zoned to sulfur-poor rims (˜1 to <0.2 wt% SO3) in apatite from the Yerington batholith, Nevada, indicate that early magma that is crystal poor, oxidizing, and sulfate rich evolved to sulfate-poor magma via crystallization of anhydrite, a mineral observed in magmas from Pinatubo and El Chichón. We predict that the characteristic zonation to sulfur-poor rims of apatite in the Yerington batholith is common in other oxidized, hydrous, calc-alkaline magmas, and can be used to track cryptic anhydrite saturation as well as to monitor sulfur evolution. Sulfate-rich arc magmas such as Yerington magmas may crystallize to produce hydrothermal fluids rich in chlorine, copper, and sulfur and porphyry copper ores.

  7. Apatite 4He/3He and (U-Th)/He evidence for an ancient Grand Canyon.

    PubMed

    Flowers, R M; Farley, K A

    2012-12-21

    The Grand Canyon is one of the most dramatic features on Earth, yet when and why it was carved have been controversial topics for more than 150 years. Here, we present apatite (4)He/(3)He thermochronometry data from the Grand Canyon basement that tightly constrain the near-surface cooling history associated with canyon incision. (4)He/(3)He spectra for eastern Grand Canyon apatites of differing He date, radiation damage, and U-Th zonation yield a self-consistent cooling history that substantially validates the He diffusion kinetic model applied here. Similar data for the western Grand Canyon provide evidence that it was excavated to within a few hundred meters of modern depths by ~70 million years ago (Ma), in contrast to the conventional model in which the entire canyon was carved since 5 to 6 Ma.

  8. Determination of the oxidation state of uranium in apatite and phosphorite deposits

    USGS Publications Warehouse

    Clarke, R.S.; Altschuler, Z.S.

    1958-01-01

    Geological and mineralogical evidence indicate that the uranium present in apatite may proxy for calcium in the mineral structure as U(IV). An experimental investigation was conducted and chemical evidence was obtained that establishes the presence of U(IV) in apatite. The following analytical procedure was developed for the determination of U(IV). Carbonatefluorapatite is dissolved in 1.5 M orthophosphoric acid at a temperature of 5??C or slightly below and fluorapatite is dissolved in cold 1.2 M hydrochloric acid (approximately 5??C) containing 1.5 g of hydroxylamine hydrochloride per 100 ml. Uranium(IV) is precipitated by cupferron using titanium as a carrier. The uranium in the precipitate is separated by use of the ethyl acetate extraction procedure and determined fluorimetrically. The validity and the limitations of the method have been established by spike experiments. ?? 1958.

  9. Apatite 4He/3He and (U-Th)/He evidence for an ancient Grand Canyon.

    PubMed

    Flowers, R M; Farley, K A

    2012-12-21

    The Grand Canyon is one of the most dramatic features on Earth, yet when and why it was carved have been controversial topics for more than 150 years. Here, we present apatite (4)He/(3)He thermochronometry data from the Grand Canyon basement that tightly constrain the near-surface cooling history associated with canyon incision. (4)He/(3)He spectra for eastern Grand Canyon apatites of differing He date, radiation damage, and U-Th zonation yield a self-consistent cooling history that substantially validates the He diffusion kinetic model applied here. Similar data for the western Grand Canyon provide evidence that it was excavated to within a few hundred meters of modern depths by ~70 million years ago (Ma), in contrast to the conventional model in which the entire canyon was carved since 5 to 6 Ma. PMID:23196906

  10. Novel bioactive Fe-based metallic glasses with excellent apatite-forming ability.

    PubMed

    Qin, Chunling; Hu, Qingfeng; Li, Yongyan; Wang, Zhifeng; Zhao, Weimin; Louzguine-Luzgin, Dmitri V; Inoue, Akihisa

    2016-12-01

    We demonstrate, for the first time, that the (Fe0.75B0.15Si0.1)100-xNbx (x=0, 1 and 3at.%) metallic glasses without toxic and allergic elements exhibit excellent apatite-forming ability in simulated body fluids (SBF), which is expected to be a new generation of biomaterials in stents and orthopedic implants. For the alloys without any surface treatment, spherical particles corresponding to octacalcium phosphate are spontaneously nucleated and precipitated throughout the alloy surface after immersion only for 1day, indicating that the present alloys possess an unusual high bioactivity. During the subsequent in-vitro immersion for 3days, SEM image reveals the typical 'cauliflower' morphology of bone-like hydroxyapatite (HA) with Ca/P ratio of 1.65. In addition, it is surprising to find that the in-vitro SBF immersion not only leads to the formation and growth of the apatite layer but also causes the progressive development of the underlying alloy substrate. Moreover, for the alloys immersed for 3 or 9days, the substrate alloy just beneath the apatite layer consists of a hierarchical nano/macro-porous structure through selective dissolution of the active components Fe and B in the surface. XPS analysis indicates that the apatite nucleation on the present alloys in SBF is attributed to the specific dissolution properties of the present alloys and the fast formation of Si-OH and Fe-OH or Nb-OH functional groups, followed by combination of these groups with Ca(2+) and phosphate ions.

  11. Novel bioactive Fe-based metallic glasses with excellent apatite-forming ability.

    PubMed

    Qin, Chunling; Hu, Qingfeng; Li, Yongyan; Wang, Zhifeng; Zhao, Weimin; Louzguine-Luzgin, Dmitri V; Inoue, Akihisa

    2016-12-01

    We demonstrate, for the first time, that the (Fe0.75B0.15Si0.1)100-xNbx (x=0, 1 and 3at.%) metallic glasses without toxic and allergic elements exhibit excellent apatite-forming ability in simulated body fluids (SBF), which is expected to be a new generation of biomaterials in stents and orthopedic implants. For the alloys without any surface treatment, spherical particles corresponding to octacalcium phosphate are spontaneously nucleated and precipitated throughout the alloy surface after immersion only for 1day, indicating that the present alloys possess an unusual high bioactivity. During the subsequent in-vitro immersion for 3days, SEM image reveals the typical 'cauliflower' morphology of bone-like hydroxyapatite (HA) with Ca/P ratio of 1.65. In addition, it is surprising to find that the in-vitro SBF immersion not only leads to the formation and growth of the apatite layer but also causes the progressive development of the underlying alloy substrate. Moreover, for the alloys immersed for 3 or 9days, the substrate alloy just beneath the apatite layer consists of a hierarchical nano/macro-porous structure through selective dissolution of the active components Fe and B in the surface. XPS analysis indicates that the apatite nucleation on the present alloys in SBF is attributed to the specific dissolution properties of the present alloys and the fast formation of Si-OH and Fe-OH or Nb-OH functional groups, followed by combination of these groups with Ca(2+) and phosphate ions. PMID:27612742

  12. An evaluation of the reactivity of synthetic and natural apatites in the presence of aqueous metals.

    PubMed

    Dybowska, Agnieszka; Manning, David A C; Collins, Matthew J; Wess, Timothy; Woodgate, Stephen; Valsami-Jones, Eugenia

    2009-04-01

    Metal removal from contaminated effluents was examined following reaction with natural apatites of biological and geological origin or a synthetic hydroxylapatite (HAP). Mammalian meat and bone meal (MBM), a by-product from meat industry, was the biological apatite source. The effect of incineration on metal removal capacity of MBM and HAP was also examined. The reactivity of apatites for all tested metals (Pb, Cd, Cu and Zn) followed the general order: synthetic > biological > mineral. For all apatites tested, Pb was removed best and preferentially from multi-metal solutions. MBM and HAP (0.5 g solid) removed Pb completely from both highly concentrated single metal solutions (50 ml, 1000 mg/L Pb) and from multi-metal solutions (50 ml) with 100 mg/L each of Cd, Cu and Zn in addition to Pb. The incineration of MBM (725 degrees C and 850 degrees C) reduced significantly its capacity for removal of Zn (by 47%, from 56 mg/g to 9 mg/g) and Cd (by 38%, from 53 mg/g to 13 mg/g) in particular and to a lesser extent for Cu (by 14%, from 61 mg/g to 46 mg/g) while the removal of Pb was not affected (100 mg/g). The same pattern was observed for incinerated HAP. SEM and XRD analysis indicated that HAP reacted with the metals by precipitation of pure metal phosphates--Pb hydroxylapatite, Zn phosphate (hopeite), a Cd phosphate (identified only by ED-SEM) and Cu phosphate (libenthenite).

  13. Enhanced apatite formation on Ti metal heated in PO2-controlled nitrogen atmosphere.

    PubMed

    Hashimoto, Masami; Hayashi, Kazumi; Kitaoka, Satoshi

    2013-10-01

    The oxynitridation of biomedical titanium metal under a precisely regulated oxygen partial pressure (PO2) of 10(-14)Pa in nitrogen atmosphere at 973 K for 1 h strongly enhanced apatite formation compared with that on Ti heated in air. The factors governing the high apatite-forming ability are discussed from the viewpoint of the surface properties of Ti heated under a PO2 of 10(-14)Pa in nitrogen atmosphere determined from X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and zeta potential measurements. Nitrogen (N)-doped TiO2 (interstitial N) was formed on pure Ti heated under a PO2 of 10(-14)Pa in nitrogen atmosphere at 973 K. The XPS O1s main peak shifted toward a lower binding energy upon heating under a PO2 of 10(-14)Pa. This shift may be due to the formation of oxygen vacancies. This Ti surface had a positive zeta potential of approximately 20 mV. According to time-of-flight secondary ion mass spectroscopy results, PO4(3-) ions were predominantly adsorbed on Ti soaked in simulated body fluid (SBF) after heat treatment, followed by calcium ions. It was concluded that the apatite formation kinetics can be described using the Avrami-Erofeev equation with an Avrami index of n=2, which implies the instantaneous nucleation of apatite on the surface of Ti soaked in SBF after heat treatment at 973 K under a PO2 of 10(-14)Pa.

  14. Formation of Apatite Coatings on an Artificial Ligament Using a Plasma- and Precursor-Assisted Biomimetic Process

    PubMed Central

    Mutsuzaki, Hirotaka; Yokoyama, Yoshiro; Ito, Atsuo; Oyane, Ayako

    2013-01-01

    A plasma- and precursor-assisted biomimetic process utilizing plasma and alternate dipping treatments was applied to a Leed-Keio artificial ligament to produce a thin coating of apatite in a supersaturated calcium phosphate solution. Following plasma surface modification, the specimen was alternately dipped in calcium and phosphate ion solutions three times (alternate dipping treatment) to create a precoating containing amorphous calcium phosphate (ACP) which is an apatite precursor. To grow an apatite layer on the ACP precoating, the ACP-precoated specimen was immersed for 24 h in a simulated body fluid with ion concentrations approximately equal to those in human blood plasma. The plasma surface modification was necessary to create an adequate apatite coating and to improve the coating adhesion depending on the plasma power density. The apatite coating prepared using the optimized conditions formed a thin-film that covered the entire surface of the artificial ligament. The resulting apatite-coated artificial ligament should exhibit improved osseointegration within the bone tunnel and possesses great potential for use in ligament reconstructions. PMID:24048251

  15. Improvement in endothelial cell adhesion and retention under physiological shear stress using a laminin–apatite composite layer on titanium

    PubMed Central

    He, Fupo; Wang, Xiupeng; Maruyama, Osamu; Kosaka, Ryo; Sogo, Yu; Ito, Atsuo; Ye, Jiandong

    2013-01-01

    Apatite (Ap), laminin–apatite composite (L5Ap, L10Ap, L20Ap and L40Ap) and albumin–apatite (AlbAp) composite layers were prepared on titanium (Ti) using a supersaturated calcium phosphate solution supplemented with laminin (0, 5, 10, 20 and 40 μg ml−1) or albumin (800 μg ml−1). With an increase in the concentrations of laminin in the supersaturated calcium phosphate solutions, the amounts of laminin immobilized on the Ti increased. The number of human umbilical vein endothelial cells (HUVECs) adhered to the laminin–apatite composite layers were remarkably higher than those to the untreated Ti, Ap layer and AlbAp composite layer. The number of cells adhered to the L40Ap was 4.3 times the untreated Ti. Moreover, cells adhered to the laminin–apatite composite layers showed significantly higher cell retention under the physiological shear stress for 1 h and 2 h than those to the untreated Ti, Ap layer and AlbAp composite layer. The number of cells remaining on the L40Ap under the physiological shear stress for 2 h was 9.5 times that of the untreated Ti. The laminin–apatite composite layer is a promising interfacial layer for endothelialization of blood-contacting materials. PMID:23407573

  16. Hanford 100-N Area In Situ Apatite and Phosphate Emplacement by Groundwater and Jet Injection: Geochemical and Physical Core Analysis

    SciTech Connect

    Szecsody, James E.; Vermeul, Vincent R.; Fruchter, Jonathan S.; Williams, Mark D.; Rockhold, Mark L.; Qafoku, Nikolla; Phillips, Jerry L.

    2010-07-01

    The purpose of this study is to evaluate emplacement of phosphate into subsurface sediments in the Hanford Site 100-N Area by two different technologies: groundwater injection of a Ca-citrate-PO4 solution and water-jet injection of sodium phosphate and/or fish-bone apatite. In situ emplacement of phosphate and apatite adsorbs, then incorporates Sr-90 into the apatite structure by substitution for calcium. Overall, both technologies (groundwater injection of Ca-citrate-PO4) and water-jet injection of sodium phosphate/fish-bone apatite) delivered sufficient phosphate to subsur¬face sediments in the 100-N Area. Over years to decades, additional Sr-90 will incorporate into the apatite precipitate. Therefore, high pressure water jetting is a viable technology to emplace phosphate or apatite in shallow subsurface sediments difficult to emplace by Ca-citrate-PO4 groundwater injections, but further analysis is needed to quantify the relevant areal extent of phosphate deposition (in the 5- to 15-ft distance from injection points) and cause of the high deposition in finer grained sediments.

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

    NASA Astrophysics Data System (ADS)

    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.

  18. Fabrication of carbonate apatite block based on internal dissolution-precipitation reaction of dicalcium phosphate and calcium carbonate.

    PubMed

    Daitou, Fumikazu; Maruta, Michito; Kawachi, Giichiro; Tsuru, Kanji; Matsuya, Shigeki; Terada, Yoshihiro; Ishikawa, Kunio

    2010-05-01

    In this study, we investigated a novel method for fabrication of carbonate apatite block without ionic movement between precursor and solution by using precursor that includes all constituent ions of carbonate apatite. A powder mixture prepared from dicalcium phosphate anhydrous and calcite at appropriate Ca/P ratios (1.5, 1.67, and 1.8) was used as starting material. For preparation of specimens, the slurry made from the powder mixture and distilled water was packed in a split stainless steel mold and heat - treated, ranging from 60 degrees C to 100 degrees C up to 48 hours at 100% humidity. It appeared that carbonate apatite could be obtained above 70 degrees C and monophasic carbonate apatite could be obtained from the powder mixture at Ca/P ratio of 1.67. Carbonate content of the specimen was about 5-7%. Diametral tensile strength of the carbonate apatite blocks slightly decreased with increasing treatment temperature. The decrease in diametral tensile strength is thought to be related to the crystal size of the carbonate apatite formed.

  19. Influence of strontium for calcium substitution in bioactive glasses on degradation, ion release and apatite formation.

    PubMed

    Fredholm, Yann C; Karpukhina, Natalia; Brauer, Delia S; Jones, Julian R; Law, Robert V; Hill, Robert G

    2012-05-01

    Bioactive glasses are able to bond to bone through the formation of hydroxy-carbonate apatite in body fluids while strontium (Sr)-releasing bioactive glasses are of interest for patients suffering from osteoporosis, as Sr was shown to increase bone formation both in vitro and in vivo. A melt-derived glass series (SiO(2)-P(2)O(5)-CaO-Na(2)O) with 0-100% of calcium (Ca) replaced by Sr on a molar base was prepared. pH change, ion release and apatite formation during immersion of glass powder in simulated body fluid and Tris buffer at 37°C over up to 8 h were investigated and showed that substituting Sr for Ca increased glass dissolution and ion release, an effect owing to an expansion of the glass network caused by the larger ionic radius of Sr ions compared with Ca. Sr release increased linearly with Sr substitution, and apatite formation was enhanced significantly in the fully Sr-substituted glass, which allowed for enhanced osteoblast attachment as well as proliferation and control of osteoblast and osteoclast activity as shown previously. Studying the composition-structure-property relationship in bioactive glasses enables us to successfully design next-generation biomaterials that combine the bone regenerative properties of bioactive glasses with the release of therapeutically active Sr ions. PMID:21993007

  20. Modification of bone-like apatite nanoparticle size and growth kinetics by alizarin red S

    NASA Astrophysics Data System (ADS)

    Ibsen, Casper Jon Steenberg; Birkedal, Henrik

    2010-11-01

    The formation of nanocrystals in biomineralization such as in bone occurs under the influence of organic molecules. Prompted by this fact, the effect of alizarin red S, a dye used in in vivo bone labeling methods, on bone-like carbonated apatite nanocrystal formation was investigated as a function of alizarin red S additive concentration. The obtained nanoparticles were investigated by powder X-ray diffraction (XRD), FTIR as well thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) while the kinetics of nanoparticle formation was investigated by in situ pH and synchrotron XRD measurements. Increasing alizarin red S concentration lead to amorphous particles over a threshold concentration and to smaller crystallites in a dose-dependent fashion. Alizarin red S induced a macroscopic lattice strain that scaled linearly with the alizarin red S concentration; this effect is reminiscent of that seen in biogenic calcium carbonates. TGA showed that the amorphous particles contained significantly more water than the crystalline samples and the DSC data showed that crystallization occurs after loss of most of the included organic material. The in situ studies showed that the formation of apatite goes via the very rapid formation of an amorphous precursor that after a certain nucleation time crystallizes into apatite. This nucleation time increased exponentially with alizarin red S concentration showing that this additive strongly stabilizes the amorphous precursor phase.

  1. Mineralisation of chitosan scaffolds with nano-apatite formation by double diffusion technique.

    PubMed

    Manjubala, I; Scheler, S; Bössert, Jörg; Jandt, Klaus D

    2006-01-01

    The study of inorganic crystal assembly in organic matrices has given rise to increasing interest in various fields of materials science to the natural process of biomineralisation. To mimic the formation of hydroxyapatite as natural bone, a double diffusion technique is utilised in this study to nucleate the hydroxyapatite crystals onto three-dimensional porous polymeric scaffolds. The porous polymer scaffolds were produced from chitosan by a thermally induced lyophilisation technique, which yields highly porous, well-controlled anisotropic open pore architecture. The nucleation of hydroxyapatite crystals was initiated at ambient conditions on the surface of the polymer scaffold, which was in contact with a calcium solution chamber, due to diffusion of phosphate ions through the scaffold. The morphology of the mineralised scaffold as analysed by scanning electron microscopy shows that apatite crystals were not only formed on the surface of the scaffold, but also in the pore channels and attached to the pore walls. The X-ray diffraction and Fourier transformed infrared analyses confirmed the phase purity of the formed apatite crystals. The transmission electron microscopy analysis reveals the microstructure of the entangled nano-apatite in the chitosan polymeric matrix. The in-vitro cytocompatibility tests with osteoblast-like cells (Saos-2) demonstrated that the biomineralised scaffold is a suitable substrate for cell attachment and migration in bone tissue engineering.

  2. Synthetic apatite nanoparticles as a phosphorus fertilizer for soybean (Glycine max)

    NASA Astrophysics Data System (ADS)

    Liu, Ruiqiang; Lal, Rattan

    2014-07-01

    Some soluble phosphate salts, heavily used in agriculture as highly effective phosphorus (P) fertilizers, cause surface water eutrophication, while solid phosphates are less effective in supplying the nutrient P. In contrast, synthetic apatite nanoparticles could hypothetically supply sufficient P nutrients to crops but with less mobility in the environment and with less bioavailable P to algae in comparison to the soluble counterparts. Thus, a greenhouse experiment was conducted to assess the fertilizing effect of synthetic apatite nanoparticles on soybean (Glycine max). The particles, prepared using one-step wet chemical method, were spherical in shape with diameters of 15.8 +/- 7.4 nm and the chemical composition was pure hydroxyapatite. The data show that application of the nanoparticles increased the growth rate and seed yield by 32.6% and 20.4%, respectively, compared to those of soybeans treated with a regular P fertilizer (Ca(H2PO4)2). Biomass productions were enhanced by 18.2% (above-ground) and 41.2% (below-ground). Using apatite nanoparticles as a new class of P fertilizer can potentially enhance agronomical yield and reduce risks of water eutrophication.

  3. Apatite Formation from Amorphous Calcium Phosphate and Mixed Amorphous Calcium Phosphate/Amorphous Calcium Carbonate.

    PubMed

    Ibsen, Casper J S; Chernyshov, Dmitry; Birkedal, Henrik

    2016-08-22

    Crystallization from amorphous phases is an emerging pathway for making advanced materials. Biology has made use of amorphous precursor phases for eons and used them to produce structures with remarkable properties. Herein, we show how the design of the amorphous phase greatly influences the nanocrystals formed therefrom. We investigate the transformation of mixed amorphous calcium phosphate/amorphous calcium carbonate phases into bone-like nanocrystalline apatite using in situ synchrotron X-ray diffraction and IR spectroscopy. The speciation of phosphate was controlled by pH to favor HPO4 (2-) . In a carbonate free system, the reaction produces anisotropic apatite crystallites with large aspect ratios. The first formed crystallites are highly calcium deficient and hydrogen phosphate rich, consistent with thin octacalcium phosphate (OCP)-like needles. During growth, the crystallites become increasingly stoichiometric, which indicates that the crystallites grow through addition of near-stoichiometric apatite to the OCP-like initial crystals through a process that involves either crystallite fusion/aggregation or Ostwald ripening. The mixed amorphous phases were found to be more stable against phase transformations, hence, the crystallization was inhibited. The resulting crystallites were smaller and less anisotropic. This is rationalized by the idea that a local phosphate-depletion zone formed around the growing crystal until it was surrounded by amorphous calcium carbonate, which stopped the crystallization. PMID:27460160

  4. Synthetic apatite nanoparticles as a phosphorus fertilizer for soybean (Glycine max).

    PubMed

    Liu, Ruiqiang; Lal, Rattan

    2014-01-01

    Some soluble phosphate salts, heavily used in agriculture as highly effective phosphorus (P) fertilizers, cause surface water eutrophication, while solid phosphates are less effective in supplying the nutrient P. In contrast, synthetic apatite nanoparticles could hypothetically supply sufficient P nutrients to crops but with less mobility in the environment and with less bioavailable P to algae in comparison to the soluble counterparts. Thus, a greenhouse experiment was conducted to assess the fertilizing effect of synthetic apatite nanoparticles on soybean (Glycine max). The particles, prepared using one-step wet chemical method, were spherical in shape with diameters of 15.8 ± 7.4 nm and the chemical composition was pure hydroxyapatite. The data show that application of the nanoparticles increased the growth rate and seed yield by 32.6% and 20.4%, respectively, compared to those of soybeans treated with a regular P fertilizer (Ca(H2PO4)2). Biomass productions were enhanced by 18.2% (above-ground) and 41.2% (below-ground). Using apatite nanoparticles as a new class of P fertilizer can potentially enhance agronomical yield and reduce risks of water eutrophication. PMID:25023201

  5. Fission-track dating of apatite and zircon: An interlaboratory comparison

    USGS Publications Warehouse

    Naeser, C.W.; Zimmermann, R.A.; Cebula, G.T.

    1981-01-01

    Apatite and zircon separates from the Fish Canyon Tuff (K-Ar age, 27.9??0.7 Myr), San Juan Mtns., Colorado, have been given to over 50 laboratories for fission-track dating. Nineteen laboratories have reported fission-track ages that they have determined for apatites. Nine laboratories have reported their analysis of the zircons. The principal difference between the results reported by the laboratories reflects their choice of the decay constant. The laboratories which use a value of ??f ??? 7.0 ?? 10-17 yr-1 for the spontaneous-fission decay constant of 238U, report an average age for the apatite of 28.5??0.7 Myr, and those using ??f ??? = 8.4 ?? 10-17 yr-1 report an average age of 23.6??1.0 Myr. The average fission-track age for the zircons is 28.4??0.7 Myr. Only laboratories which use ??f ??? 7.0 ?? 10-17 yr-1 reported zircon data. ?? 1981.

  6. New advances in nanocrystalline apatite colloids intended for cellular drug delivery.

    PubMed

    Bouladjine, Amal; Al-Kattan, Ahmed; Dufour, Pascal; Drouet, Christophe

    2009-10-20

    Intracellular drug delivery using colloidal biomimetic calcium phosphate apatites as nanocarriers is a seducing concept. However, the colloid preparation to an industrial scale requires the use of easily handled raw materials as well as the possibility to tailor the nanoparticles size. In this work, the stabilization of the colloids was investigated with various biocompatible agents. Most interestingly, nanoscale colloids were obtained without the need for toxic and/or hazardous raw materials. Physico-chemical characteristics were investigated by chemical analyses, dynamic light scattering, FTIR/Raman spectroscopies, XRD, and electron microscopy. A particularly promising colloidal system associates biomimetic apatite stabilized with a natural phospholipid moiety (AEP(r), 2-aminoethylphosphoric acid). Complementary data described such colloids as apatite nanocrystals covered with surface Ca(2+)(AEP(r)(-))(2) complexes involving "supernumerary" Ca(2+) ions. The effects of the concentration in AEPr, synthesis temperature, duration of aging in solution, pH, and sonication were followed, showing that it is possible to modulate the mean size of the nanoparticles, typically in the range 30-100 nm. The perfect biocompatibility of such colloids allied to the possibility to prepare them from innocuous compounds shows great promise for intracellular drug delivery.

  7. In vitro and in vivo biocompatibility of apatite-coated magnetite nanoparticles for cancer therapy.

    PubMed

    Múzquiz-Ramos, Elia Martha; Cortés-Hernández, D A; Escobedo-Bocardo, J C; Zugasti-Cruz, Alejandro; Ramírez-Gómez, X S; Osuna-Alarcón, J G

    2013-04-01

    The aim of this study was to determine the biocompatibility and potential toxicity of apatite-coated magnetite nanoparticles. The in vitro biocompatibility with human red blood cells was evaluated, not hemolytic effects were found at concentrations lower than 3 mg/ml. For the in vivo study, Balb/c mice were used. The animals were injected intravenously or intraperitoneally, the doses ranged from 100 to 2,500 mg/Kg. All the injected animals showed normal kidney and liver function. No significant changes were found in the body weight, the organs weight and the iron levels in liver due to the administration. In conclusion, apatite-coated magnetite nanoparticles did not induce any abnormal clinical signs in the laboratory animals. The results demonstrated that apatite-coated magnetite nanoparticles of 8 ± 2 nm in size did not have hemolytic effect in human erythrocytes and did not cause apparent toxicity in Balb/c mice under the experimental conditions of this study.

  8. Bone-like apatite coating on functionalized poly(etheretherketone) surface via tailored silanization layers technique.

    PubMed

    Zheng, Yanyan; Xiong, Chengdong; Zhang, Shenglan; Li, Xiaoyu; Zhang, Lifang

    2015-10-01

    Poly(etheretherketone) (PEEK) is a rigid semi-crystalline polymer with outstanding mechanical properties, bone-like stiffness and suitable biocompatibility that has attracted much interest as a biomaterial for orthopedic and dental implants. However, the bio-inert surface of PEEK limits its biomedical applications when direct osteointegration between the implants and the host tissue is desired. In this work, -PO4H2, -COOH and -OH groups were introduced on the PEEK surface by further chemical treatments of the vinyl-terminated silanization layers formed on the hydroxylation-pretreated PEEK surface. Both the surface-functionalized and pristine specimens were characterized by X-ray photoelectron spectroscopy (XPS), attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy and water contact angle measurements. When placed in 1.5 strength simulated body fluid (SBF) solution, apatite was observed to form uniformly on the functionalized PEEK surface and firmly attach to the substrate. The characterized results demonstrated that the coating was constituted by poorly crystallized bone-like apatite and the effect of surface functional groups on coating formation was also discussed in detail. In addition, in vitro biocompatibility of PEEK, in terms of pre-osteoblast cell (MC3T3-E1) attachment, spreading and proliferation, was remarkably enhanced by the bone-like apatite coating. Thus, this study provides a method to enhance the bioactivity of PEEK and expand its applications in orthopedic and dental implants. PMID:26117784

  9. Combinatorial MAPLE deposition of antimicrobial orthopedic maps fabricated from chitosan and biomimetic apatite powders.

    PubMed

    Visan, A; Stan, G E; Ristoscu, C; Popescu-Pelin, G; Sopronyi, M; Besleaga, C; Luculescu, C; Chifiriuc, M C; Hussien, M D; Marsan, O; Kergourlay, E; Grossin, D; Brouillet, F; Mihailescu, I N

    2016-09-10

    Chitosan/biomimetic apatite thin films were grown in mild conditions of temperature and pressure by Combinatorial Matrix-Assisted Pulsed Laser Evaporation on Ti, Si or glass substrates. Compositional gradients were obtained by simultaneous laser vaporization of the two distinct material targets. A KrF* excimer (λ=248nm, τFWHM=25ns) laser source was used in all experiments. The nature and surface composition of deposited materials and the spatial distribution of constituents were studied by SEM, EDS, AFM, GIXRD, FTIR, micro-Raman, and XPS. The antimicrobial efficiency of the chitosan/biomimetic apatite layers against Staphylococcus aureus and Escherichia coli strains was interrogated by viable cell count assay. The obtained thin films were XRD amorphous and exhibited a morphology characteristic to the laser deposited structures composed of nanometric round shaped grains. The surface roughness has progressively increased with chitosan concentration. FTIR, EDS and XPS analyses indicated that the composition of the BmAp-CHT C-MAPLE composite films gradually modified from pure apatite to chitosan. The bioevaluation tests indicated that S. aureus biofilm is more susceptible to the action of chitosan-rich areas of the films, whilst the E. coli biofilm proved more sensible to areas containing less chitosan. The best compromise should therefore go, in our opinion, to zones with intermediate-to-high chitosan concentration which can assure a large spectrum of antimicrobial protection concomitantly with a significant enhancement of osseointegration, favored by the presence of biomimetic hydroxyapatite.

  10. Shear-mediated crystallization from amorphous calcium phosphate to bone apatite.

    PubMed

    Niu, Xufeng; Wang, Liyang; Tian, Feng; Wang, Lizhen; Li, Ping; Feng, Qingling; Fan, Yubo

    2016-02-01

    The contribution of fluid shear stress (FSS) on the conversion of amorphous calcium phosphate (ACP) to bone apatite is investigated. The ACP precursors are prepared by using a wet-chemistry method and further exposed to the constant FSS environment with values of 0.5, 1.0, 1.5, and 2.0Pa. At the designated time points, the apatites are characterized by transmission electron microscopy, X-ray diffraction, and inductively coupled plasma-mass spectroscopy. The results show that, the low FSS (≤1.0Pa) has positive effects on the transition of ACP, characterized by the accelerated crystallization velocity and the well-organized calcium-deficient hydroxyapatite (CDHA) structure, whereas the high FSS (>1.0Pa) has negative effects on this conversion process, characterized by the poor CDHA crystal morphologies and the destroyed structures. The bioactivity evaluations further reveal that, compared with the FSS-free group, the CDHA prepared under 1.0Pa FSS for 9h presents the more biocompatible features with pre-osteoblast cells. These results are helpful for understanding the mechanism of apatite deposition in natural bone tissue.

  11. In vivo bioactivity of titanium and fluorinated apatite coatings for orthopaedic implants: a vibrational study

    NASA Astrophysics Data System (ADS)

    Taddei, Paola; Tinti, Anna; Reggiani, Matteo; Monti, Patrizia; Fagnano, Concezio

    2003-06-01

    The bone integration of implants is a complex process which depends on chemical composition and surface morphology. To accelerate osteointegration, metal implants are coated with porous metal or apatites which have been reported to increase mineralisation, improving prosthesis fixation. To study the influence of composition and morphology on the in vivo bioactivity, titanium screws coated by Plasma Flame Spraying (PFS) with titanium or fluorinated apatite (K690) were implanted in sheep tibia and femur for 10 weeks and studied by micro-Raman and IR spectroscopy. The same techniques, together with thermogravimetry, were used for characterising the pre-coating K690 powder. Contrary to the manufacturer report, the K690 pre-coating revealed to be composed of a partially fluorinated apatite containing impurities of Ca(OH) 2 and CaCO 3. By effect of PFS, the impurities were decomposed and the crystallinity degree of the coating was found to decrease. The vibrational spectra recorded on the implanted screws revealed the presence of newly formed bone; for the K690-coated screws at least, a high level of osteointegration was evidenced.

  12. Young asteroidal fluid activity revealed by absolute age from apatite in carbonaceous chondrite

    PubMed Central

    Zhang, Ai-Cheng; Li, Qiu-Li; Yurimoto, Hisayoshi; Sakamoto, Naoya; Li, Xian-Hua; Hu, Sen; Lin, Yang-Ting; Wang, Ru-Cheng

    2016-01-01

    Chondritic meteorites, consisting of the materials that have formed in the early solar system (ESS), have been affected by late thermal events and fluid activity to various degrees. Determining the timing of fluid activity in ESS is of fundamental importance for understanding the nature, formation, evolution and significance of fluid activity in ESS. Previous investigations have determined the relative ages of fluid activity with short-lived isotope systematics. Here we report an absolute 207Pb/206Pb isochron age (4,450±50 Ma) of apatite from Dar al Gani (DaG) 978, a type ∼3.5, ungrouped carbonaceous chondrite. The petrographic, mineralogical and geochemical features suggest that the apatite in DaG 978 should have formed during metamorphism in the presence of a fluid. Therefore, the apatite age represents an absolute age for fluid activity in an asteroidal setting. An impact event could have provided the heat to activate this young fluid activity in ESS. PMID:27682449

  13. Synthetic apatite nanoparticles as a phosphorus fertilizer for soybean (Glycine max).

    PubMed

    Liu, Ruiqiang; Lal, Rattan

    2014-07-14

    Some soluble phosphate salts, heavily used in agriculture as highly effective phosphorus (P) fertilizers, cause surface water eutrophication, while solid phosphates are less effective in supplying the nutrient P. In contrast, synthetic apatite nanoparticles could hypothetically supply sufficient P nutrients to crops but with less mobility in the environment and with less bioavailable P to algae in comparison to the soluble counterparts. Thus, a greenhouse experiment was conducted to assess the fertilizing effect of synthetic apatite nanoparticles on soybean (Glycine max). The particles, prepared using one-step wet chemical method, were spherical in shape with diameters of 15.8 ± 7.4 nm and the chemical composition was pure hydroxyapatite. The data show that application of the nanoparticles increased the growth rate and seed yield by 32.6% and 20.4%, respectively, compared to those of soybeans treated with a regular P fertilizer (Ca(H2PO4)2). Biomass productions were enhanced by 18.2% (above-ground) and 41.2% (below-ground). Using apatite nanoparticles as a new class of P fertilizer can potentially enhance agronomical yield and reduce risks of water eutrophication.

  14. Influence of strontium for calcium substitution in bioactive glasses on degradation, ion release and apatite formation

    PubMed Central

    Fredholm, Yann C.; Karpukhina, Natalia; Brauer, Delia S.; Jones, Julian R.; Law, Robert V.; Hill, Robert G.

    2012-01-01

    Bioactive glasses are able to bond to bone through the formation of hydroxy-carbonate apatite in body fluids while strontium (Sr)-releasing bioactive glasses are of interest for patients suffering from osteoporosis, as Sr was shown to increase bone formation both in vitro and in vivo. A melt-derived glass series (SiO2–P2O5–CaO–Na2O) with 0–100% of calcium (Ca) replaced by Sr on a molar base was prepared. pH change, ion release and apatite formation during immersion of glass powder in simulated body fluid and Tris buffer at 37°C over up to 8 h were investigated and showed that substituting Sr for Ca increased glass dissolution and ion release, an effect owing to an expansion of the glass network caused by the larger ionic radius of Sr ions compared with Ca. Sr release increased linearly with Sr substitution, and apatite formation was enhanced significantly in the fully Sr-substituted glass, which allowed for enhanced osteoblast attachment as well as proliferation and control of osteoblast and osteoclast activity as shown previously. Studying the composition–structure–property relationship in bioactive glasses enables us to successfully design next-generation biomaterials that combine the bone regenerative properties of bioactive glasses with the release of therapeutically active Sr ions. PMID:21993007

  15. Combinatorial MAPLE deposition of antimicrobial orthopedic maps fabricated from chitosan and biomimetic apatite powders.

    PubMed

    Visan, A; Stan, G E; Ristoscu, C; Popescu-Pelin, G; Sopronyi, M; Besleaga, C; Luculescu, C; Chifiriuc, M C; Hussien, M D; Marsan, O; Kergourlay, E; Grossin, D; Brouillet, F; Mihailescu, I N

    2016-09-10

    Chitosan/biomimetic apatite thin films were grown in mild conditions of temperature and pressure by Combinatorial Matrix-Assisted Pulsed Laser Evaporation on Ti, Si or glass substrates. Compositional gradients were obtained by simultaneous laser vaporization of the two distinct material targets. A KrF* excimer (λ=248nm, τFWHM=25ns) laser source was used in all experiments. The nature and surface composition of deposited materials and the spatial distribution of constituents were studied by SEM, EDS, AFM, GIXRD, FTIR, micro-Raman, and XPS. The antimicrobial efficiency of the chitosan/biomimetic apatite layers against Staphylococcus aureus and Escherichia coli strains was interrogated by viable cell count assay. The obtained thin films were XRD amorphous and exhibited a morphology characteristic to the laser deposited structures composed of nanometric round shaped grains. The surface roughness has progressively increased with chitosan concentration. FTIR, EDS and XPS analyses indicated that the composition of the BmAp-CHT C-MAPLE composite films gradually modified from pure apatite to chitosan. The bioevaluation tests indicated that S. aureus biofilm is more susceptible to the action of chitosan-rich areas of the films, whilst the E. coli biofilm proved more sensible to areas containing less chitosan. The best compromise should therefore go, in our opinion, to zones with intermediate-to-high chitosan concentration which can assure a large spectrum of antimicrobial protection concomitantly with a significant enhancement of osseointegration, favored by the presence of biomimetic hydroxyapatite. PMID:27418570

  16. Biomimetic Deposition of Apatite on Surface Chemically Modified Porous NiTi Shapememory Alloy

    NASA Astrophysics Data System (ADS)

    Wu, S. L.; Liu, X. M.; Chung, C. Y.; Chu, Paul K.; Chan, Y. L.; Yeung, K. W. K.; Chu, C. L.

    Porous NiTi shape memory alloy (SMA) with 48% porosity and an average pore size of 50-800 μm was synthesized by capsule-free hot isostatic pressing (CF-HIP). To enhance the surface bioactivity, the porous NiTi SMA was subjected to H2O2 and subsequent NaOH treatment. Scanning electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy analyses revealed that a porous sodium titanate (Na2TiO3) film had formed on the surface of the porous NiTi SMA. An apatite layer was deposited on this film after immersion in simulated body fluid at 37°C, while no apatite could be found on the surface of the untreated porous NiTi SMA. The formation of the apatite layer infers that the bioactivity of the porous NiTi SMA may be enhanced by surface chemical treatment, which is favorable for its application as bone implants.

  17. Long-term evaluation of the degradation behavior of three apatite-forming calcium phosphate cements.

    PubMed

    An, Jie; Liao, Hongbing; Kucko, Nathan W; Herber, Ralf-Peter; Wolke, Joop G C; van den Beucken, Jeroen J J P; Jansen, John A; Leeuwenburgh, Sander C G

    2016-05-01

    Calcium phosphate cements (CPCs) are injectable bone substitutes with a long clinical history because of their biocompatibility and osteoconductivity. Nevertheless, their cohesion upon injection into perfused bone defects as well as their long-term degradation behavior remain major clinical challenges. Therefore, the long-term degradation behavior of two types of α-tricalcium phosphate-based, apatite-forming CPCs was compared to a commercially available apatite-forming cement, that is HydroSet™ . Carboxyl methylcellulose (CMC) was used as cohesion promotor to improve handling properties of the two experimental cements, whereas poly (d, l-lactic-co-glycolic) acid (PLGA) microparticles were added to introduce macroporosity and stimulate CPC degradation. All three CPCs were injected into defects drilled into rabbit femoral condyles and explanted after 4, 12, or 26 weeks, after which the bone response was assessed both qualitatively and quantitatively. CPCs without PLGA microparticles degraded only at the periphery of the implants, while the residual CPC volume was close to 90%. On the contrary, bone ingrowth was observed not only at the periphery of the CPC, but also throughout the center of the implants after 26 weeks of implantation for the PLGA-containing CPCs with a residual CPC volume of approximately 55%. In conclusion, it was shown that CPC containing CMC and PLGA was able to induce partial degradation of apatite-forming CPCs and concomitant replacement by bone tissue. PMID:26743230

  18. Luminescence properties of Pr3+ and Sm3+ ions in natural apatites

    NASA Astrophysics Data System (ADS)

    Czaja, M.; Bodył, S.; Lisiecki, R.; Mazurak, Z.

    2010-07-01

    The luminescence spectra of Pr3+ and Sm3+ ions in apatite Ca5[F∣(PO4)3] crystals from Spain and Russia have been compared with those for phosphate glasses doped with Pr3+, Sm3+ and Pr3+, Sm3+ ions. Time-resolved spectra measurements confirm that, in apatites, samarium ions occupy two non-equivalent crystal sites; the same is assumed for praseodymium ions. For the first time in minerals, the Stark splitting energy levels Δ E for 3H6 and 1D2 of Pr3+ ion and 6H7/2 of Sm3+ ion were determined. Some small differences in Δ E values for the Spanish and Russian apatite are discussed. The decay times of the excited levels of Pr3+, Sm3+ and Pr3+, Sm3+ doped in phosphate glass were measured at room temperature and at 77 K. The energy transfer process between samarium and praseodymium ions was observed and the energy transfer rate was calculated.

  19. Fabrication and Characterization of Biomimetic Collagen-Apatite Scaffolds with Tunable Structures for Bone Tissue Engineering

    PubMed Central

    Xia, Zengmin; Yu, Xiaohua; Jiang, Xi; Brody, Harold D; Rowe, David W; Wei, Mei

    2013-01-01

    The objective of the current study is to prepare a biomimetic collagen-apatite (Col-Ap) scaffold for improved bone repair and regeneration. A novel bottom-up approach has been developed, which combines a biomimetic self-assembly method with a controllable freeze casting technology. In this study, the mineralized collagen fibers were generated using a simple one-step co-precipitation method which involved collagen self-assembly and in situ apatite precipitation in a collagen-containing modified simulated body fluid (m-SBF). The precipitates were subjected to controllable freeze casting, forming scaffolds with either an isotropic equiaxed structure or a unidirectional lamellar structure. These scaffolds were comprised of collagen fibers and poorly crystalline bone-like carbonated apatite nanoparticles. The mineral content in the scaffold could be tailored in a range 0–54 wt% by simply adjusting the collagen content in the m-SBF. Further, the mechanisms of the formation of both the equiaxed and the lamellar scaffolds were investigated, and freezing regimes for equiaxed and lamellar solidification were established. Finally, bone forming capability of such prepared scaffolds was evaluated in vivo in a mouse calvarial defect model. It was confirmed that the scaffolds well support new bone formation. PMID:23567944

  20. A taxonomy of apatite frameworks for the crystal chemical design of fuel cell electrolytes

    SciTech Connect

    Pramana, Stevin S.; Klooster, Wim T.; White, Timothy J.

    2008-08-15

    Apatite framework taxonomy succinctly rationalises the crystallographic modifications of this structural family as a function of chemical composition. Taking the neutral apatite [La{sub 8}Sr{sub 2}][(GeO{sub 4}){sub 6}]O{sub 2} as a prototype electrolyte, this classification scheme correctly predicted that 'excess' oxygen in La{sub 9}SrGe{sub 6}O{sub 26.5} is tenanted in the framework as [La{sub 9}Sr][(GeO{sub 4}){sub 5.5}(GeO{sub 5}){sub 0.5}]O{sub 2}, rather than the presumptive tunnel location of [La{sub 9}Sr][(GeO{sub 4}){sub 6}]O{sub 2.5}. The implication of this approach is that in addition to the three known apatite genera-A{sub 10}(BO{sub 3}){sub 6}X{sub 2}, A{sub 10}(BO{sub 4}){sub 6}X{sub 2}, A{sub 10}(BO{sub 5}){sub 6}X{sub 2}-hybrid electrolytes of the types A{sub 10}(BO{sub 3}/BO{sub 4}/BO{sub 5}){sub 6}X{sub 2} can be designed, with potentially superior low-temperature ion conduction, mediated by the introduction of oxygen to the framework reservoir. - Graphical abstract: Apatite framework taxonomy succinctly rationalises the crystallographic modifications of this structural family as a function of chemical composition. Neutron diffraction identified that the excess oxygen in La{sub 9}SrGe{sub 6}O{sub 26.5} is tenanted in the framework as [La{sub 9}Sr][(GeO{sub 4}){sub 5.5}(GeO{sub 5}){sub 0.5}]O{sub 2}. The implication of this approach is that in addition to the three known apatite genera-A{sub 10}(BO{sub 3}){sub 6}X{sub 2}, A{sub 10}(BO{sub 4}){sub 6}X{sub 2}, A{sub 10}(BO{sub 5}){sub 6}X{sub 2}-hybrid electrolytes of the types A{sub 10}(BO{sub 3}/BO{sub 4}/BO{sub 5}){sub 6}X{sub 2} can be designed.

  1. Orientation Dependent Polarized Micro-XAS Study of U, Th and Sr in Single Crystal Apatites

    NASA Astrophysics Data System (ADS)

    Luo, Y.; Rakovan, J.; Wright, S.

    2009-05-01

    In order to evaluate apatite as a potential solid nuclear waste form and a contaminant sequestration agent, the complimentary use of single crystal X-ray diffraction and X-ray absorption spectroscopy (XAS) is applied to the study of U, Th, and Sr doped apatite single crystals to investigate the site preference, oxidation state, and structural distortions created by these substituents. Single crystal X-ray diffraction provides average information regarding the site occupancy of U and Th in apatites. Extended X-ray absorption fine-structure (EXAFS) yields quantitative information of the local structure of these substituents, which includes near-neighbor distances, coordination numbers and variations in bond distances; while X-ray absorption near edge structure (XANES) is used to determine the oxidation states of U. Restricted by the typical small size (20-100 μm) and volume of our synthetic samples, Micro-XAS is required. Different from studies which take full advantage of the polarization of synchrotron radiation, our Micro- XAS study on single crystal apatites was hampered by the polarization effects. In order to extract precise information of valence state and structural variation from XAS, it is necessary to know the crystallographic orientation of the sample with respect to the polarization direction of the incident X-ray beam during data collection. To do this we have designed and built a portable goniometer that duplicates the geometry of our laboratory standard Bruker Apex diffractometer goniometer. Crystal orientation is determined by X-ray diffraction at our home institution. The portable goniometer is then set up on the experimental table at synchrotron facilities and the crystal can be set in any specific known orientation. The lattice orientation determined by X-ray diffraction is applied to XAS data analysis, specifically calculation of scattering amplitudes and phase shifts, to account for polarization effects of synchrotron radiation. The goniometer

  2. The kinetics of clumped-isotope reactions in calcite and apatite from natural and experimental samples

    NASA Astrophysics Data System (ADS)

    Stolper, D. A.; Eiler, J. M.

    2014-12-01

    Measurements of clumped isotopes of carbonate-bearing minerals are a powerful tool for reconstructing past surface temperatures and thermal histories of shallow crustal rocks. Because the clumped-isotope thermometer is based on homogenous-phase equilibrium, a sample's clumped-isotope temperature is susceptible to resetting through, for example, intracrystalline diffusion and redistribution of C and O isotopes during (re)heating or slow cooling. Quantitative knowledge of the kinetics of this resetting have received increasing attention (1-3) and is critical for understanding the meaning of clumped-isotope temperatures of samples with complex burial histories. To better constrain these kinetics and complement previous work (1-3) we performed heating experiments (400-700°C) on optical calcites and carbonate-bearing apatites. As previously observed (2-3), calcites exhibit non-first-order kinetics. The data were fit using a model that incorporates both diffusion and isotope-exchange reactions (4). The kinetics derived with this model using the optical-calcite heating experiments of (2) and those measured here are indistinguishable. The model predicts that subtle changes (>10°C) in measured calcite clumped-isotope temperatures can occur at burial temperatures between 60-100°C on million-year timescales. Though small, such changes may have an impact on clumped-isotope-based reconstructions of past surface temperatures and thermal histories. The derived kinetics were compared to clumped-isotope measurements of cogenetic calcites and apatites from slowly cooled carbonatite intrusions. Apparent temperatures are 70-140°C for apatites and 120-190°C for calcites. Measured temperatures for calcites match modeled temperatures using reasonable geological cooling rates. Natural apatite samples yield lower apparent temperatures than predicted based on the model. We propose that this difference is the result of annealment of structural damage in apatites (e.g., generated by

  3. Molasses enhanced phyto and bioremediation treatability study of explosives contaminated Hawaiian soils.

    PubMed

    Lamichhane, Krishna M; Babcock, Roger W; Turnbull, Steve J; Schenck, Susan

    2012-12-01

    A 15-week treatability study was conducted in a greenhouse to evaluate the potential effects of molasses on the bioremediation and phytoremediation potential of Guinea Grass (Panicum maximum) for treating energetic contaminated soil from the open burn/open detonation area of the Makua Military Reservation, Oahu, HI (USA). The energetics in the soil were royal demolition explosive (RDX) and high-melting explosive (HMX). Among the 6 treatments employed in this study, enhanced removal of RDX was observed from treatments that received molasses and went to completion. The RDX degradation rates in treatments with molasses diluted 1:20 and 1:40 were comparable suggesting that the lower dose worked as well as the higher dose. Treatments without molasses degraded RDX slowly and residuals remained after 15 weeks. The bacterial densities in molasses-treated units were much greater than those without molasses. Phytoremediation alone seems to have little effect on RDX disappearance. For HMX, neither bioremediation nor phytoremediation was found to be useful in reducing the concentration within the experimental period. The concentrations of nitrogen and phosphorous in the soil did not change significantly during the experiment, however, a slight increase in soil pH was observed in all treatments. The study showed that irrigating with diluted molasses is effective at enhancing RDX degradation mainly in the root zone and just below it. The long term sustainability of active training ranges can be enhanced by bioremediation using molasses treatments to prevent RDX deposited by on-going operations from migrating through the soil to groundwater and off-site.

  4. Short-Term Assessment of Risk and Treatability (START): systematic review and meta-analysis.

    PubMed

    O'Shea, Laura E; Dickens, Geoffrey L

    2014-09-01

    This article describes a systematic review of the psychometric properties of the Short-Term Assessment of Risk and Treatability (START) and a meta-analysis to assess its predictive efficacy for the 7 risk domains identified in the manual (violence to others, self-harm, suicide, substance abuse, victimization, unauthorized leave, and self-neglect) among institutionalized patients with mental disorder and/or personality disorder. Comprehensive terms were used to search 5 electronic databases up to January 2013. Additional articles were located by examining references lists and hand-searching. Twenty-three papers were selected to include in the narrative review of START's properties, whereas 9 studies involving 543 participants were included in the meta-analysis. Studies about the feasibility and utility of the tool had positive results but lacked comparators. START ratings demonstrated high internal consistency, interrater reliability, and convergent validity with other risk measures. There was a lack of information about the variability of START ratings over time. Its use in an intervention to reduce violence in forensic psychiatric outpatients was not better than standard care. START risk estimates demonstrated strong predictive validity for various aggressive outcomes and good predictive validity for self-harm. Predictive validity for self-neglect and victimization was no better than chance, whereas evidence for the remaining outcomes is derived from a single, small study. Only 3 of the studies included in the meta-analysis were rated to be at a low risk of bias. Future research should aim to investigate the predictive validity of the START for the full range of adverse outcomes, using well-designed methodologies, and validated outcome tools. PMID:24796344

  5. Mortality from treatable illnesses in marginally housed adults: a prospective cohort study

    PubMed Central

    Jones, Andrea A; Vila-Rodriguez, Fidel; Leonova, Olga; Langheimer, Verena; Lang, Donna J; Barr, Alasdair M; Procyshyn, Ric M; Smith, Geoffrey N; Schultz, Krista; Buchanan, Tari; Krausz, Michael; Montaner, Julio S; MacEwan, G William; Rauscher, Alexander; Panenka, William J; Thornton, Allen E; Honer, William G

    2015-01-01

    Objectives Socially disadvantaged people experience greater risk for illnesses that may contribute to premature death. This study aimed to evaluate the impact of treatable illnesses on mortality among adults living in precarious housing. Design A prospective cohort based in a community sample. Setting A socially disadvantaged neighbourhood in Vancouver, Canada. Participants Adults (N=371) living in single room occupancy hotels or recruited from the Downtown Community Court and followed for median 3.8 years. Main outcome measures Participants were assessed for physical and mental illnesses for which treatment is currently available. We compared cohort mortality rates with 2009 Canadian rates. Left-truncated Cox proportional hazards modelling with age as the time scale was used to assess risk factors for earlier mortality. Results During 1269 person-years of observation, 31/371 (8%) of participants died. Compared with age-matched and sex-matched Canadians, the standardised mortality ratio was 8.29 (95% CI 5.83 to 11.79). Compared with those that had cleared the virus, active hepatitis C infection was a significant predictor for hepatic fibrosis adjusting for alcohol dependence and age (OR=2.96, CI 1.37 to 7.08). Among participants <55 years of age, psychosis (HR=8.12, CI 1.55 to 42.47) and hepatic fibrosis (HR=13.01, CI 3.56 to 47.57) were associated with earlier mortality. Treatment rates for these illnesses were low (psychosis: 32%, hepatitis C virus: 0%) compared with other common disorders (HIV: 57%, opioid dependence: 61%) in this population. Conclusions Hepatic fibrosis and psychosis are associated with increased mortality in people living in marginal conditions. Timely diagnosis and intervention could reduce the high mortality in marginalised inner city populations. PMID:26297373

  6. Reduced Sleep Spindles in Schizophrenia: A Treatable Endophenotype That Links Risk Genes to Impaired Cognition?

    PubMed

    Manoach, Dara S; Pan, Jen Q; Purcell, Shaun M; Stickgold, Robert

    2016-10-15

    Although schizophrenia (SZ) is defined by waking phenomena, abnormal sleep is a common feature. In particular, there is accumulating evidence of a sleep spindle deficit. Sleep spindles, a defining thalamocortical oscillation of non-rapid eye movement stage 2 sleep, correlate with IQ and are thought to promote long-term potentiation and enhance memory consolidation. We review evidence that reduced spindle activity in SZ is an endophenotype that impairs sleep-dependent memory consolidation, contributes to symptoms, and is a novel treatment biomarker. Studies showing that spindles can be pharmacologically enhanced in SZ and that increasing spindles improves memory in healthy individuals suggest that treating spindle deficits in patients with SZ may improve cognition. Spindle activity is highly heritable, and recent large-scale genome-wide association studies have identified SZ risk genes that may contribute to spindle deficits and illuminate their mechanisms. For example, the SZ risk gene CACNA1I encodes a calcium channel that is abundantly expressed in the thalamic spindle generator and plays a critical role in spindle activity based on a mouse knockout. Future genetic studies of animals and humans can delineate the role of this and other genes in spindles. Such cross-disciplinary research, by forging empirical links in causal chains from risk genes to proteins and cellular functions to endophenotypes, cognitive impairments, symptoms, and diagnosis, has the potential to advance the mechanistic understanding, treatment, and prevention of SZ. This review highlights the importance of deficient sleep-dependent memory consolidation among the cognitive deficits of SZ and implicates reduced sleep spindles as a potentially treatable mechanism.

  7. Pilot-scale treatability test plan for the 100-HR-3 operable unit

    SciTech Connect

    Not Available

    1994-08-01

    This document presents the treatability test plan for pilot-scale pump-and-treat testing at the 100-HR-3 Operable Unit. The test will be conducted in fulfillment of interim Milestone M-15-06E to begin pilot-scale pump-and-treat operations by August 1994. The scope of the test was determined based on the results of lab/bench-scale tests (WHC 1993a) conducted in fulfillment of Milestone M-15-06B. These milestones were established per agreement between the U.S. Department of Energy (DOE), the Washington State Department of Ecology and the U.S. Environmental Protection Agency (EPA), and documented on Hanford Federal of Ecology Facility Agreement and Consent Order Change Control Form M-15-93-02. This test plan discusses a pilot-scale pump-and-treat test for the chromium plume associated with the D Reactor portion of the 100-HR-3 Operable Unit. Data will be collected during the pilot test to assess the effectiveness, operating parameters, and resource needs of the ion exchange (IX) pump-and-treat system. The test will provide information to assess the ability to remove contaminants by extracting groundwater from wells and treating extracted groundwater using IX. Bench-scale tests were conducted previously in which chromium VI was identified as the primary contaminant of concern in the 100-D reactor plume. The DOWEX 21K{trademark} resin was recommended for pilot-scale testing of an IX pump-and-treat system. The bench-scale test demonstrated that the system could remove chromium VI from groundwater to concentrations less than 50 ppb. The test also identified process parameters to monitor during pilot-scale testing. Water will be re-injected into the plume using wells outside the zone of influence and upgradient of the extraction well.

  8. MEDNIK syndrome: a novel defect of copper metabolism treatable by zinc acetate therapy.

    PubMed

    Martinelli, Diego; Travaglini, Lorena; Drouin, Christian A; Ceballos-Picot, Irene; Rizza, Teresa; Bertini, Enrico; Carrozzo, Rosalba; Petrini, Stefania; de Lonlay, Pascale; El Hachem, Maya; Hubert, Laurence; Montpetit, Alexandre; Torre, Giuliano; Dionisi-Vici, Carlo

    2013-03-01

    MEDNIK syndrome-acronym for mental retardation, enteropathy, deafness, neuropathy, ichthyosis, keratodermia-is caused by AP1S1 gene mutations, encoding σ1A, the small subunit of the adaptor protein 1 complex, which plays a crucial role in clathrin coat assembly and mediates trafficking between trans-Golgi network, endosomes and the plasma membrane. MEDNIK syndrome was first reported in a few French-Canadian families sharing common ancestors, presenting a complex neurocutaneous phenotype, but its pathogenesis is not completely understood. A Sephardic-Jewish patient, carrying a new AP1S1 homozygous mutation, showed severe perturbations of copper metabolism with hypocupremia, hypoceruloplasminemia and liver copper accumulation, along with intrahepatic cholestasis. Zinc acetate treatment strikingly improved clinical conditions, as well as liver copper and bile-acid overload. We evaluated copper-related metabolites and liver function retrospectively in the original French-Canadian patient series. Intracellular copper metabolism and subcellular localization and function of copper pump ATP7A were investigated in patient fibroblasts. Copper metabolism perturbation and hepatopathy were confirmed in all patients. Studies in mutant fibroblasts showed abnormal copper incorporation and retention, reduced expression of copper-dependent enzymes cytochrome-c-oxidase and Cu/Zn superoxide dismutase, and aberrant intracellular trafficking of Menkes protein ATP7A, which normalized after rescue experiments expressing wild-type AP1S1 gene. We solved the pathogenetic mechanism of MEDNIK syndrome, demonstrating that AP1S1 regulates intracellular copper machinery mediated by copper-pump proteins. This multisystem disease is characterized by a unique picture, combining clinical and biochemical signs of both Menkes and Wilson's diseases, in which liver copper overload is treatable by zinc acetate therapy, and can now be listed as a copper metabolism defect in humans. Our results may also

  9. Molasses enhanced phyto and bioremediation treatability study of explosives contaminated Hawaiian soils.

    PubMed

    Lamichhane, Krishna M; Babcock, Roger W; Turnbull, Steve J; Schenck, Susan

    2012-12-01

    A 15-week treatability study was conducted in a greenhouse to evaluate the potential effects of molasses on the bioremediation and phytoremediation potential of Guinea Grass (Panicum maximum) for treating energetic contaminated soil from the open burn/open detonation area of the Makua Military Reservation, Oahu, HI (USA). The energetics in the soil were royal demolition explosive (RDX) and high-melting explosive (HMX). Among the 6 treatments employed in this study, enhanced removal of RDX was observed from treatments that received molasses and went to completion. The RDX degradation rates in treatments with molasses diluted 1:20 and 1:40 were comparable suggesting that the lower dose worked as well as the higher dose. Treatments without molasses degraded RDX slowly and residuals remained after 15 weeks. The bacterial densities in molasses-treated units were much greater than those without molasses. Phytoremediation alone seems to have little effect on RDX disappearance. For HMX, neither bioremediation nor phytoremediation was found to be useful in reducing the concentration within the experimental period. The concentrations of nitrogen and phosphorous in the soil did not change significantly during the experiment, however, a slight increase in soil pH was observed in all treatments. The study showed that irrigating with diluted molasses is effective at enhancing RDX degradation mainly in the root zone and just below it. The long term sustainability of active training ranges can be enhanced by bioremediation using molasses treatments to prevent RDX deposited by on-going operations from migrating through the soil to groundwater and off-site. PMID:23164624

  10. Induction Tempering vs Conventional Tempering of a Heat-Treatable Steel

    NASA Astrophysics Data System (ADS)

    Sackl, Stephanie; Zuber, Michael; Clemens, Helmut; Primig, Sophie

    2016-07-01

    An induction heat treatment is favorable compared to a conventional one mainly due to significant time and cost savings. Therefore, in this study, the microstructure property relationships during induction and conventional heat treatment of a heat treatable steel 42CrMo4 is investigated. The yield strength and hardness is slightly higher for the conventionally heat-treated steel, whereas the induction heat-treated condition exhibits a roughly 30 J/cm2 higher impact energy. In a previous investigation of the authors, it has been proved that the difference in yield strength originates from the smaller block size of the conventionally heat-treated steel, which was already present after hardening. In the present work, it can be shown that during tempering the martensitic blocks become equi-axed ferrite grains due to recrystallization as revealed by electron back scatter diffraction. Nevertheless, a larger grain size usually is less favorable for the impact toughness of steels. Therefore, another mechanism is responsible for the higher impact energy of the induction hardened and tempered steel. With the aid of transmission electron microscopy a finer distribution of cementite was observed in the induction heat-treated samples. The delay of recovery is the reason for the presence of finer cementite in case of the induction heat-treated steel. Here, the higher heating rates and shorter process times reduce the annihilation of dislocation and as a consequence provide more nucleation sites for precipitation of cementite during tempering. From the obtained experimental results, it is believed that the finer distribution of carbides causes the observed higher impact toughness.

  11. Savannah River Site chemical, metal, and pesticide (CMP) waste vitrification treatability studies

    SciTech Connect

    Cicero, C.A.

    1997-01-13

    Numerous Department of Energy (DOE) facilities, as well as Department of Defense (DOD) and commercial facilities, have used earthen pits for disposal of chemicals, organic contaminants, and other waste materials. Although this was an acceptable means of disposal in the past, direct disposal into earthen pits without liners or barriers is no longer a standard practice. At the Savannah River Site (SRS), approximately three million pounds of such material was removed from seven chemical, metal, and pesticide disposal pits. This material is known as the Chemical, Metal, and Pesticide (CMP) Pit waste and carries several different listed waste codes depending on the contaminants in the respective storage container. The waste is not classified as a mixed waste because it is believed to be non-radioactive; however, in order to treat the material in a non-radioactive facility, the waste would first have to be screened for radioactivity. The Defense Waste Processing Technology (DWPT) Section of the Savannah River Technology Center (SRTC) was requested by the DOE-Savannah River (SR) office to determine the viability of vitrification of the CMP Pit wastes. Radioactive vitrification facilities exist which would be able to process this waste, so the material would not have to be analyzed for radioactive content. Bench-scale treatability studies were performed by the DWPT to determine whether a homogeneous and durable glass could be produced from the CMP Pit wastes. Homogeneous and durable glasses were produced from the six pits sampled. The optimum composition was determined to be 68.5 wt% CMP waste, 7.2 wt% Na{sub 2}O, 9 wt% CaO, 7.2 wt% Li{sub 2}O and 8.1 wt% Fe{sub 2}O{sub 3}. This glass melted at 1,150 C and represented a two fold volume reduction.

  12. Monazite, iron oxide and barite exsolutions in apatite aggregates from CCSD drillhole eclogites and their geological implications

    NASA Astrophysics Data System (ADS)

    Sun, Xiaoming; Tang, Qian; Sun, Weidong; Xu, Li; Zhai, Wei; Liang, Jinlong; Liang, Yeheng; Shen, Kun; Zhang, Zeming; Zhou, Bing; Wang, Fangyue

    2007-06-01

    We have identified abundant exsolutions in apatite aggregates from eclogitic drillhole samples of the Chinese Continental Scientific Drilling (CCSD) project. Electron microscope and laser Raman spectroscopy analyses show that the apatite is fluorapatite, whereas exsolutions that can be classified into four types: (A) platy to rhombic monazite exsolutions; (B) needle-like hematite exsolutions; (C) irregular magnetite and hematite intergrowths; and (D) needle-like strontian barite exsolutions. The widths and lengths of type A monazite exsolutions range from about 6-10 μm (mostly 6 μm) and about 50-75 μm, respectively. Type B exsolutions are parallel with the C axis of apatite, with widths ranging from 0.5 to 2 μm, with most around 1.5 μm, and lengths that vary dramatically from 6 to 50 μm. Type C exsolutions are also parallel with the C axis of apatite, with lengths of ˜30-150 μm and widths of ˜10 to 50 μm. Type D strontian barite exsolutions coexist mostly with type B hematite exsolutions, with widths of about 9 μm and lengths of about 60-70 μm. Exsolutions of types B, C and D have never been reported in apatites before. Most of the exsolutions are parallel with the C axis of apatite, implying that they were probably exsolved at roughly the same time. Dating by the chemical Th-U-total Pb isochron method (CHIME) yields an U-Pb isochron age of 202 ± 28 Ma for monazite exsolutions, suggesting that these exsolutions were formed during recrystallization and retrograde metamorphism of the exhumed ultrahigh pressure (UHP) rocks. Quartz veins hosting apatite aggregates were probably formed slightly earlier than 202 Ma. Abundant hematite exsolutions, as well as coexistence of magnetite/hematite and barite/hematite in the apatite, suggest that the oxygen fugacity of apatite aggregates is well above the sulfide-sulfur oxide buffer (SSO). Given that quartz veins host these apatite aggregates, they were probably deposited from SiO 2-rich hydrous fluids formed during

  13. Using Apatite to Model Chlorine Contents of High SiO2 Magmas: An Enhanced Methodological Approach

    NASA Astrophysics Data System (ADS)

    Flesch, R.; Webster, J. D.; Nadeau, P. A.

    2015-12-01

    Hydrothermal experiments were conducted on high-silica (73-75 wt% SiO2), fluid-saturated melts at 844-862°C and ca. 50 MPa using crushed glass of the Los Posos rhyolite. Water and salts including NaCl, KCl, Ca(OH)2, and CaHPO4 and HCl were added proportionally to the experiments to restrict the variability of the aluminosity of the melt. The Durango apatite, which contains 3.53 wt% F and 0.41% Cl, was added as "seeds"<5µm in diameter to stimulate apatite growth during the experiments. Samples were loaded into gold capsules and run in cold-seal pressure vessels for durations of 286-1008 hours. Temperature was cycled at ±20˚C to promote apatite crystallization. Electron microprobe analyses of run-product glasses and embedded apatite grains support calculation of a range of partition coefficients ( = wt% Cl in apatite/wt% Cl in melt) of 4.7 to 15.9. The mole fraction of Cl in experimental apatites, or XCl, ranges from 0.19 to 0.56, while XF ranges from 0.08 to 0.63. The computed values for XOH range from 0.24 to 0.38. We find that normalizing XCl to XOH of apatites dramatically improves the precision when using apatite compositions to model Cl contents of melts. We compare our Los Posos rhyolite experiments with published data on 50 MPa rhyodacite experiments and find that Cl partitioning is significantly different in each system. Given the importance of chlorine in fluid equilibria, ore transport, and magma evolution, applications of apatite as a proxy for Cl contents in melts are unbounded. It is found that in order to accurately use the volatile composition of natural and synthetic apatites to calculate the volatile composition of melts in felsic systems, several chemical factors, including wt% SiO2 and the aluminosity/alkalinity of melts, should be incorporated as parameters to enhance relevant modeling. This allows geochemists to place better constraints on processes associated with crystallizing Cl-bearing magmatic systems.

  14. Ion microprobe U-Pb dating and strontium isotope analysis of biogenic apatite

    NASA Astrophysics Data System (ADS)

    Sano, Y.; Toyoshima, K.; Takahata, N.; Shirai, K.

    2012-12-01

    Conodonts are micro-fossils chemically composed of apatite which occurred in the body of one animal. They are guide fossils to show formation ages of sedimentary sequences with the highest resolution [1] and good samples to verify the dating method. We developed the ion microprobe U-Pb dating of apatite [2] and applied the method to a Carboniferous conodont [3] by using a SHRIMP II installed at Department of Earth and Planetary Sciences, Hiroshima University. Recently we have developed the NanoSIMS U-Pb dating method and successfully measured the formation ages of monazite [4] and zircon [5] at Atmosphere and Ocean Research Institute, University of Tokyo. In this work we carried out the NanoSIMS U-Pb dating of biogenic apatite such as conodont. Since the spot size of NanoSIMS is smaller than SHRIMP II, it is easier to have multi-spots on the single fragment of biogenic apatite. Based on the isochron method of U-Pb system, we have calculated the formation ages. They are consistent with those in literature. In order to study the chemical evolution of ocean during the past 600 Million years, strontium isotopes (87Sr/86Sr) of fossil marine carbonate such as coral skeletons and foraminifera tests were measured and compiled [6]. However they are not robust when the age is older than 500Ma, partly due to post-depositional histories. Apatite is more stable and more resistant to the alteration than carbonate [7]. Recently we have developed the method of NanoSIMS strontium isotopic analysis of a fish otolith, which composed of aragonite [8]. In this work we carried out the strontium isotopic analysis of biogenic apatite. The advantage of the ion microprobe technique over the TIMS (thermal ionization mass spectrometer) and MC-ICP-MS (multi-collector inductively coupled argon plasma mass spectrometer) method is preservation of the important textural context and to provide an opportunity for other simultaneous analytical work with high spatial resolution. This is the case for

  15. Combining apatite fission track and He thermochronology to constrain thermal histories

    NASA Astrophysics Data System (ADS)

    Persano, C.; Stuart, F.; Bishop, P.

    2003-04-01

    Apatite fission track thermochronometry (AFTT) has proved an invaluable tool for determining the cooling histories of rocks in the shallow crust. Quantitative models for the time and temperature dependence of the fission track annealing process in apatite demostrate that the combination of fission track apparent age and track length distribution provides a continuous record of the thermal history of the samples from 120 to 60^oC, and possibly, to lower temperatures. However the sensitivity of the technique is poorly constrained below 70-80^oC because annealing rates are slow. The apatite (U-Th)/He system is sensitive to temperatures between 80 and 40^oC irrespective of apatite chemistry, and presents a way to test the ability of AFTT to determine thermal histories below 80^oC. Here we present a novel way of combining apatite fission track and (U-Th)/He data that narrows the number of possible thermal histories and provides better constraints on the landscape evolution of a particular region. We use as an example the southeastern Australia passive margin in NSW, an area where post break-up landscape evolution is poorly resolved despite an extensive fission track database. Fission track and (U-Th)/He ages have been measured on 16 apatite samples from two coast perpendicular traverses across the coastal plain, up the escarpment onto the plateau. The fission track data are modelled using AFTSolve and the individual thermal histories which fit the data are used as parameters for forward modelling the apatite He ages. Only the thermal histories that produce the measured He age, within uncertainty, are considered. For each sample, the choosen time-temperature paths show the same peculiar characteristics, narrowing considerably the number of possible cooling scenarios. This combination shows that the AFT/derived thermal histories for temperatures between 60 to 40^oC may be inconsistent with the (U-Th)/He ages, suggesting that the annealing process at this temperatures

  16. High temperature (>350 °C) thermochronology and mechanisms of Pb loss in apatite

    NASA Astrophysics Data System (ADS)

    Cochrane, Ryan; Spikings, Richard A.; Chew, David; Wotzlaw, Jörn-Frederik; Chiaradia, Massimo; Tyrrell, Shane; Schaltegger, Urs; Van der Lelij, Roelant

    2014-02-01

    Natural processes driven by heat flow can be understood using quantitative reconstruction of the thermal history of accessory and common minerals that were formed or modified in these processes. Thermochronology assumes that isotopes are lost from minerals by thermally-activated volume diffusion, and forms the basis of many studies of the thermal evolution of the crust. However, some studies challenge this assumption and suggest that the mechanisms controlling isotope transport in minerals over geological time-scales are dominated by aqueous fluid flow within mineral pathways. Here, we test these contrasting hypotheses by inverse modelling apatite uranium-lead (U-Pb) dates to produce theoretical t-T solutions assuming Pb was lost by volume diffusion. These solutions are compared with independent geological constraints and intra-grain apatite U-Pb dates, which demonstrate that volume diffusion governed the displacement of Pb. This confirmation, combined with an inverse-modeling procedure that permits reheating and cooling paths to be distinguished between ˜375 and 570 °C, provides geologists with a unique tool for investigating the high-temperature thermal evolution of accessory minerals using the U-Pb method. The positive relationship between grain size and U-Pb dates obtained by TIMS, combined with consistent t-T paths derived from TIMS and MC-LA-ICP-MS data suggests that Pb was lost from apatites in the studied leucosome by thermally activated diffusion. Pb-loss by mechanisms that involve aqueous interaction are not required to account for the U-Pb dates. Apatite grains with elevated Th/U ratios yield U-Pb dates that are younger than predicted from the relationship between grain size and date. The cause of the discrepancy is unknown, although it may be due to variations in intrinsic diffusion properties in apatites of varying composition. Alternatively, the young ages may be due to accelerated Pb-loss by processes that occur faster than thermally activated

  17. Biological Apatite Formed from Polyphosphate and Alkaline Phosphatase May Exchange Oxygen Isotopes from Water through Carbonate

    NASA Astrophysics Data System (ADS)

    Omelon, S. J.; Stanley, S. Y.; Gorelikov, I.; Matsuura, N.

    2011-12-01

    The oxygen isotopic composition in bone mineral phosphate is known to reflect the local water composition, environmental humidity, and diet1. Once ingested, biochemical processes presumably equilibrate PO43- with "body water" by the many biochemical reactions involving PO43- 2. Blake et al. demonstrated that enzymatic release of PO43- from organophosphorus compounds, and microbial metabolism of dissolved orthophosphate, significantly exchange the oxygen in precipitated apatite within environmental water3,4, which otherwise does not exchange with water at low temperatures. One of the enzymes that can cleave phosphates from organic substrates is alkaline phosphastase5, the enzyme also associated with bone mineralization. The literature often states that the mineral in bone in hydroxylapatite, however the mineral in bone is carbonated apatite that also contains some fluoride6. Deprotonation of HPO32- occurs at pH 12, which is impossibly high for biological system, and the predominate carbonate species in solution at neutral pH is HCO3-. To produce an apatite mineral without a significant hydroxyl content, it is possible that apatite biomineralization occurs through a polyphosphate pathway, where the oxygen atom required to transform polyphosphate into individual phosphate ions is from carbonate: [PO3-]n + CO32- -> [PO3-]n-1 + PO43- + CO2. Alkaline phosphatase can depolymerise polyphosphate into orthophosphate5. If alkaline phosphatase cleaves an oxygen atom from a calcium-carbonate complex, then there is no requirement for removing a hydrogen atom from the HCO3- or HPO43- ions of body water to form bioapatite. A mix of 1 mL of 1 M calcium polyphosphate hydogel, or nano-particles of calcium polyphosphate, and amorphous calcium carbonate were reacted with alkaline phosphatase, and maintained at neutral to basic pH. After two weeks, carbonated apatite and other calcium phosphate minerals were identified by powder x-ray diffraction. Orthophosphate and unreacted

  18. Inter- and intra-crystal REE variations in apatite from the Bob Ingersoll pegmatite, Black Hills, South Dakota

    SciTech Connect

    Jolliff, B.L.; Papike, J.J.; Shearer, C.K. ); Shimizu, N. )

    1989-02-01

    Concentrations of rare earth elements (REE) have been measured on a suite of apatite crystals from an internally zoned granitic pegmatite enriched in Li, B, Be, F, Nb, Ta, Sn and U with a Cameca IMS 3f ion microprobe using energy filtering. An apatite specimen from the Tin Mountain pegmatite, analyzed previously by isotope dilution, was used as a standard. The chondrite-normalized pattern determined with the ion microprobe closely matches the pattern determined by isotope dilution, with maxima at Sm and Dy, and minima at Nd and Er. Apatite samples from the Bob Ingersoll pegmatite show a large range of REE patterns and concentrations. In one case, apatite crystals within millimeters show differences in REE concentrations and pattern shapes, including a switch from positive to negative Eu anomalies. These effects may be coupled with non-ideal partitioning of REE in a heterogeneous mixture of melt, aqueous fluid and crystals. REE concentrations in apatite samples from the different pegmatite zones indicate a large variation in outer zones, high concentrations near the pegmatite core, and very low concentration in the core. Patterns are flat to slightly inclined (Ce/Yb: 1 to 5), and most samples have positive Eu anomalies. The magnitude of positive Eu anomalies decreases with inward position in the pegmatite, possibly indicating a progressive increase in {line integral}O{sub 2}, and a sharp increase may be indicated by systematic Ce depletion in apatite from the pegmatite core. REE-specific volatile complexes may contribute to variations, including unusual kinks, observed in REE patterns of apatite from mineral assemblages in upper parts of the pegmatite.

  19. Facile preparation of apatite-type lanthanum silicate by a new water-based sol–gel process

    SciTech Connect

    Yamagata, Chieko; Elias, Daniel R.; Paiva, Mayara R.S.; Misso, Agatha M.; Castanho, Sonia R.H. Mello

    2013-06-01

    Highlights: ► We use a Na{sub 2}SiO{sub 3} waste solution as source of Si. ► We present a simple, rapid and low temperature method of lanthanum silicate apatite preparation. ► TEOS, a high cost reagent, was successfully substituted by a cheap price Na{sub 2}SiO{sub 3}, to obtain pure La{sub 9.56}(SiO{sub 4})6O{sub 2.33} lanthanum silicate apatite. - Abstract: In recent years, apatite-type lanthanum silicates ([Ln{sub 10−x}(XO{sub 4})6O{sub 3–1.5x}] (X = Si or Ge)) have been studied for use in SOFC (solid oxide fuel cells), at low temperature (600–800 °C), due to its ionic conductivity which is higher than that of YSZ (Yttrium Stabilized Zirconia) electrolyte. For this reason they are very promising materials as solid electrolyte for SOFCs. Synthesis of functional nanoparticles is a challenge in the nanotechnology. In this work, apatite-type lanthanum silicate nanoparticles were synthesized by a water-based sol–gel process, i.e., sol–gel technique followed by chemical precipitation of lanthanum hydroxide on the gel of the silica. Na{sub 2}SiO{sub 3} waste solution was used as silica source. Spherical aerogel silica was prepared by acid catalyzed reaction, followed by precipitation of lanthanum hydroxide to obtain the precursor of apatite-type lanthanum silicate. Powders of apatite-type lanthanum silicate achieved from the precursor were characterized by thermal analysis, X-ray diffraction (XRD), scanning electron microscopy (SEM) and specific surface area measurements (BET). The apatite phase was formed at 900 °C.

  20. Laboratory treatability studies preparatory to field testing a resting-cell in situ microbial filter bioremediation strategy

    SciTech Connect

    Taylor, R.T.; Hanna, M.L.

    1995-04-01

    Prior to a down-hole-column treatability test of a Methylosinus trichosporium OB3b attached-resting-cell in situ biofilter strategy, a set of three sequential laboratory experiments were carried out to define several key operational parameters and to evaluate the likely degree of success at a NASA Kennedy Space Center site. They involved the cell attachment to site-specific sediments, the intrinsic resting-cell biotransformation capacities for the contaminants of interest plus their time-dependent extents of biodegradative removal at the concentrations of concern, and a scaled in situ mini-flow-through-column system that closely mimics the subsurface conditions during a field-treatability or pilot test of an emplaced resting-cell filter. These experiments established the conditions required for the complete metabolic removal of a vinyl chloride (VC), cis-dichlororthylene (cis-DCE) and trichloroethylene (TCE) mixture. However, the gas chromatographic (GC) procedures that we utilized and the mini-flow-through column data demonstrated that, at most, only about 50--70% of the site-water VC, cis-DCE, and TCE would be biodegraded. This occurred because of a limiting level of dissolved oxygen, which was exacerbated by the simultaneous presence of several additional previously unrecognized groundwater components, especially methane, that are also competing substrates for the whole-cell soluble methane monooxygenase (sMMO) enzyme complex. Irrespective, collectively the simplicity of the methods that we have developed and the results obtainable with them appear to provide relevant laboratory-based test-criteria before taking our microbial filter strategy to an in situ field treatability or pilot demonstration stage at other sites in the future.

  1. Sulfur concentration and isotopic variation in apatites from granitic to granodioritic plutons of a Cretaceous Cordilleran Batholith

    NASA Astrophysics Data System (ADS)

    Economos, R. C.

    2012-12-01

    Apatite is a common igneous accessory mineral with a high saturation temperature which can therefore crystallize over a significant portion of magmatic compositional space. Sulfur presents an opportunity to identify zoning in apatites. Unlike other trace elements, sulfur is relatively immobile in the apatite crystal structure and can be present in typical concentrations up to 1500 - 2000 ppm (or 0.5 to 1 wt% SO3). Sulfur concentration zoning in igneous apatites from ore producing magmatic systems has been identified (Streck and Dilles, 1998), but the interpretation of the cause of this zoning remains an open question. δ34S isotopic ratios of whole apatites have been used to track isotopic evolution associated with changes in magma fO2 and eruptive degassing (Rye, 2005). The presented work combines sulfur concentration mapping in zoned apatite crystals with in-situ SIMS 34S and 32S isotope measurements. Apatites were extracted from granite to granodiorite samples from the Cadiz Valley Batholith in the central Mojave Desert. This batholith is related to the pulse of Cretaceous Cordilleran magmatism that generated large batholiths in the Sierra Nevada and the Penninsular Ranges. The Mojave segment of the Cretaceous arc is unique in their construction into a full thickness of continental crust which exerted a strong influence on magmatic compositions. Apatite grains were mounted parallel to C axes, ground until grains were approximately bisected, and analyzed by Electron Microprobe at UCLA, for CaO, P2O5, SO3 and SiO2. Grains were surveyed and those yielding anomalous SO3 contents were investigated by micron-scale concentration mapping. Typical SO3 concentrations of apatites from all samples were ~0.2 wt%, while 8 to 10% of apatite grains from two samples contained cores with concentrations ranging up to 0.5 wt%. The sulfur zoning in these samples is oscillatory, in some grains representing 5 to 6 repetitions of high and low concentrations. Based on these textures

  2. The increase of apatite layer formation by the poly(3-hydroxybutyrate) surface modification of hydroxyapatite and β-tricalcium phosphate.

    PubMed

    Szubert, M; Adamska, K; Szybowicz, M; Jesionowski, T; Buchwald, T; Voelkel, A

    2014-01-01

    The aim of this study was the surface modification of hydroxyapatite and β-tricalcium phosphate by poly(3-hydroxybutyrate) grafting and characterization of modificates. The bioactivity examination was carried out by the determination to grow an apatite layer on modified materials during incubation in simulated body fluid at 37°C. The additional issue taken up in this paper was to investigate the influence of fluid replacement. The process of the surface modification of biomaterials was evaluated by means of infrared and Raman spectroscopy. Formation of the apatite layer was assessed by means of scanning electron microscopy and confirmed by energy dispersive, Raman and Fourier transformed infrared spectroscopy. During exposure in simulated body fluid, the variation of the zeta potential, pH measurement and relative weight was monitored. Examination of scanning electron microscopy micrographs suggests that modification of hydroxyapatite and β-tricalcium phosphate by poly(3-hydroxybutyrate) significantly increases apatite layer formation. Raman spectroscopy evaluation revealed that the formation of the apatite layer was more significant in the case of hydroxyapatite modificate, when compared to the β-tricalcium phosphate modificate. Both modificates were characterized by stable pH, close to the natural pH of human body fluids. Furthermore, we have shown that a weekly changed, simulated body fluid solution increases apatite layer formation.

  3. Microstructure and leach rates of apatite glass-ceramics as a host for Sr high-level liquid waste

    NASA Astrophysics Data System (ADS)

    He, Yong; Bao, Weimin; Song, Chongli

    2002-10-01

    An apatite glass-ceramic wasteform with 21 wt% SrO loading was fabricated for immobilizing Sr high-level liquid waste. The normalized leach rates of Sr, K, Mo, Al, P, Si are 6.9×10 -4, 1.09×10 -1, 2.7×10 -3, 3.22×10 -2, 2.84×10 -2, 3.26×10 -2 g/m 2 day, respectively. Component Fe in all leachates is not detectable in the 28-day static leaching test procedure in MCC-1. Instead of leaching, component Ca is adsorbed by testing samples. All the component Mo concentrates in the glass matrix of the well crystallized apatite glass-ceramics. For an apatite glass-ceramic wasteform, the optimum microstructure should be one in which poorly crystallized apatite crystallites distribute evenly in the glass phase. Perfect crystallization makes the crystal phase more stoichiometric and significantly changes the composition of the coexisting glass phase in the system, which, in our case, decreases the chemical stability of the apatite glass-ceramics.

  4. Bile Acid Malabsorption After Pelvic and Prostate Intensity Modulated Radiation Therapy: An Uncommon but Treatable Condition

    SciTech Connect

    Harris, Victoria; Benton, Barbara; Sohaib, Aslam; Dearnaley, David; Andreyev, H. Jervoise N.

    2012-12-01

    Purpose: Intensity modulated radiation therapy (IMRT) is a significant therapeutic advance in prostate cancer, allowing increased tumor dose delivery and increased sparing of normal tissues. IMRT planning uses strict dose constraints to nearby organs to limit toxicity. Bile acid malabsorption (BAM) is a treatable disorder of the terminal ileum (TI) that presents with symptoms similar to radiation therapy toxicity. It has not been described in patients receiving RT for prostate cancer in the contemporary era. We describe new-onset BAM in men after IMRT for prostate cancer. Methods and Materials: Diagnosis of new-onset BAM was established after typical symptoms developed, selenium-75 homocholic acid taurine (SeHCAT) scanning showed 7-day retention of <15%, and patients' symptoms unequivocally responded to a bile acid sequestrant. The TI was identified on the original radiation therapy plan, and the radiation dose delivered was calculated and compared with accepted dose-volume constraints. Results: Five of 423 men treated in a prospective series of high-dose prostate and pelvic IMRT were identified with new onset BAM (median age, 65 years old). All reported having normal bowel habits before RT. The volume of TI ranged from 26-141 cc. The radiation dose received by the TI varied between 11.4 Gy and 62.1 Gy (uncorrected). Three of 5 patients had TI treated in excess of 45 Gy (equivalent dose calculated in 2-Gy fractions, using an {alpha}/{beta} ratio of 3) with volumes ranging from 1.6 cc-49.0 cc. One patient had mild BAM (SeHCAT retention, 10%-15%), 2 had moderate BAM (SeHCAT retention, 5%-10%), and 2 had severe BAM (SeHCAT retention, <5%). The 3 patients whose TI received {>=}45 Gy developed moderate to severe BAM, whereas those whose TI received <45 Gy had only mild to moderate BAM. Conclusions: Radiation delivered to the TI during IMRT may cause BAM. Identification of the TI from unenhanced RT planning computed tomography scans is difficult and may impede accurate

  5. Evaluating apatite formation and osteogenic activity of electrospun composites for bone tissue engineering.

    PubMed

    Patlolla, Ajitha; Arinzeh, Treena Livingston

    2014-05-01

    Significant interest has been in examining calcium phosphate ceramics, specifically β-tricalcium phosphate (β-TCP) (Ca3 (PO4)2 ) and synthetic hydroxyapatite (HA) (Ca10 (PO4)6 (OH)2 ), in composites and more recently, in fibrous composites formed using the electrospinning technique for bone tissue engineering applications. Calcium phosphate ceramics are sought because they can be bone bioactive, which means an apatite forms on their surface that facilitates bonding to bone tissue, and are osteoconductive. However, studies examining the bioactivity of electrospun composites containing calcium phosphates and their corresponding osteogenic activity have been limited. In this study, electrospun composites consisting of (20/80) HA/TCP nanoceramics and poly (ϵ-caprolactone) (PCL) were fabricated. Solvent and solvent combinations were evaluated to form scaffolds with a maximum concentration and dispersion of ceramic and pore sizes large enough for cell infiltration and tissue growth. PCL was dissolved in either methylene chloride (Composite-MC) or a combination of methylene chloride (80%) and dimethylformamide (20%; Composite-MC + DMF). Composites were evaluated in vitro for degradation, apatite formation, and osteogenic differentiation of human mesenchymal stem cells (MSCs) with an emphasis on temporal gene expression of osteogenic markers and the pluripotent gene Sox-2. Apatite formation and the osteogenic differentiation was the greatest for Composite-MC as determined by gene expression, protein production and biochemical markers, even without the presence of osteoinductive factors in the media, in comparison to Composite-MC + DMF and unfilled PCL mats. Sox-2 levels also reduced over time. The results of this study demonstrate that the solvent or solvent combination used in preparing the electrospun composite mats plays a critical role in determining their bioactivity which may, in turn, affect cell behavior.

  6. A Bayesian approach to calibrating apatite fission track annealing models for laboratory and geological timescales

    NASA Astrophysics Data System (ADS)

    Stephenson, John; Gallagher, Kerry; Holmes, Chris

    2006-10-01

    We present a new approach for modelling annealing of fission tracks in apatite, aiming to address various problems with existing models. We cast the model in a fully Bayesian context, which allows us explicitly to deal with data and parameter uncertainties and correlations, and also to deal with the predictive uncertainties. We focus on a well-known annealing algorithm [Laslett, G.M., Green, P.F., Duddy, I.R., Gleadow. A.J.W., 1987. Thermal annealing of fission tracks in apatite. 2. A quantitative-analysis. Chem. Geol., 65 (1), 1-13], and build a hierachical Bayesian model to incorporate both laboratory and geological timescale data as direct constraints. Relative to the original model calibration, we find a better (in terms of likelihood) model conditioned just on the reported laboratory data. We then include the uncertainty on the temperatures recorded during the laboratory annealing experiments. We again find a better model, but the predictive uncertainty when extrapolated to geological timescales is increased due to the uncertainty on the laboratory temperatures. Finally, we explictly include a data set [Vrolijk, P., Donelick, R.A., Quenq, J., Cloos. M., 1992. Testing models of fission track annealing in apatite in a simple thermal setting: site 800, leg 129. In: Larson, R., Lancelet, Y. (Eds.), Proceedings of the Ocean Drilling Program, Scientific Results, vol. 129, pp. 169-176] which provides low-temperature geological timescale constraints for the model calibration. When combined with the laboratory data, we find a model which satisfies both the low-temperature and high-temperature geological timescale benchmarks, although the fit to the original laboratory data is degraded. However, when extrapolated to geological timescales, this combined model significantly reduces the well-known rapid recent cooling artifact found in many published thermal models for geological samples.

  7. Authigenic apatite formation and burial in sediments from non-upwelling, continental margin environments

    SciTech Connect

    Ruttenberg, K.C.; Berner, R.A. )

    1993-03-01

    Evidence for precipitation of authigenic carbonate fluorapatite (CFA) in Long Island Sound and Mississippi Delta sediments suggests that formation of CFA is not restricted to environments of active coastal upwelling. The authors present porewater data suggestive of CFA formation in both these areas. Application of a sequential leaching procedure, designed specifically to separate authigenic carbonate fluorapatite from other phosphorus-containing phases, including detrital apatite of igneous or metamorphic origin, provides strong supporting evidence for authigenic apatite formation in these sediments. The size of the authigenic apatite reservoir increases with depth, indicating continued formation of CFA during early diagenesis. This depth increase is mirrored by a decrease in solid-phase organic P at both sites, suggesting that CFA is forming at the expense of organic P. Mass balance considerations, application of diagenetic models to intersitital water nutrient data, and the saturation state of the interstitial water are consistent with this interpretation. Diagenetic redistribution of phosphorus among the different solid-phase reservoirs is observed at both sites, and results in near perfect retention of P by these sediments over the depth intervals sampled. Formation of CFA in continental margins which do not conform to the classically defined regions of phosphorite formation renders CFA a quantitatively more important sink than has previously been recognized. Including this reservoir as a newly identified sink for reactive P in the ocean, the residence time of P in the modern ocean must be revised downward. The implication for ancient oceans of CFA formation in continental margin sediments other than phosphorites is that phosphorite formation may be less a representation of episodicity in removal of reactive P from the oceans than of localized concentration of CFA in phosphatic sediments by secondary physical processes. 90 refs., 5 figs., 2 tabs.

  8. The status of strontium in biological apatites: an XANES/EXAFS investigation.

    PubMed

    Bazin, Dominique; Dessombz, Arnaud; Nguyen, Christelle; Ea, Hang Korng; Lioté, Frédéric; Rehr, John; Chappard, Christine; Rouzière, Stephan; Thiaudière, Dominique; Reguer, Solen; Daudon, Michel

    2014-01-01

    Osteoporosis represents a major public health problem through its association with fragility fractures. The public health burden of osteoporotic fractures will rise in future generations, due in part to an increase in life expectancy. Strontium-based drugs have been shown to increase bone mass in postmenopausal osteoporosis patients and to reduce fracture risk but the molecular mechanisms of the action of these Sr-based drugs are not totally elucidated. The local environment of Sr(2+) cations in biological apatites present in pathological and physiological calcifications in patients without such Sr-based drugs has been assessed. In this investigation, X-ray absorption spectra have been collected for 17 pathological and physiological calcifications. These experimental data have been combined with a set of numerical simulations using the ab initio FEFF9 X-ray spectroscopy program which takes into account possible distortion and Ca/Sr substitution in the environment of the Sr(2+) cations. For selected samples, Fourier transforms of the EXAFS modulations have been performed. The complete set of experimental data collected on 17 samples indicates that there is no relationship between the nature of the calcification (physiological and pathological) and the adsorption mode of Sr(2+) cations (simple adsorption or insertion). Such structural considerations have medical implications. Pathological and physiological calcifications correspond to two very different preparation procedures but are associated with the same localization of Sr(2+) versus apatite crystals. Based on this study, it seems that for supplementation of Sr at low concentration, Sr(2+) cations will be localized into the apatite network. PMID:24365928

  9. Apatite fission-track thermochronology of the central and southern Appalachian Basin

    SciTech Connect

    Roden, M.K.

    1989-01-01

    Samples were collected in west to east transects across the Appalachian Basin of Pennsylvania, Maryland, West Virginia, and Virginia. These samples locations were chosen to test the concept of increasing paleotemperature due to increasing burial from west to east across the Appalachian Basin and to detect any thermal anomalies that exist. Calculated time-temperature (tT) paths based on apatite fission-track apparent ages and confined track length distributions for samples from this study indicate that both the Pennsylvania and southern Appalachian had complex uplift and cooling histories. In Pennsylvania, the Tioga and Kalkberg ash bed samples from central Pennsylvania yield modelled tT paths that indicate early post-Alleghanian (285-270 Ma) cooling with uplift estimated at beginning at {approx}251 {plus minus} 25 Ma. Samples from the western Allegheny Plateau and Allegheny Front contain apatites which have reset to give fission-track ages and track lengths consistent with tT histories beginning at <200 Ma. In northeastern Pennsylvania on the Allegheny Plateau, the modelled tT paths show rapid cooling from temperatures in the range of 110{degree}-120{degree} C at 170-160 Ma. In the southern Appalachian Basin, calculated tT paths indicate that uplift in the northern section was immediately post-Alleghanian folding with uplift beginning first in the northwestern section on the Cumberland Plateau at {approx}226 {plus minus} 23 Ma and progressing to the eastern Valley and Ridge Province of Virginia at {approx}119 {plus minus} 12 Ma. The samples from southwestern Virginia yield a mean apatite fission-track apparent age of 175 {plus minus} 11 Ma which may be the result of a higher heat flow, higher paleogeothermal gradient during the Upper Jurassic-Early Cretaceous extension along the Atlantic Coast.

  10. Evaluating apatite formation and osteogenic activity of electrospun composites for bone tissue engineering.

    PubMed

    Patlolla, Ajitha; Arinzeh, Treena Livingston

    2014-05-01

    Significant interest has been in examining calcium phosphate ceramics, specifically β-tricalcium phosphate (β-TCP) (Ca3 (PO4)2 ) and synthetic hydroxyapatite (HA) (Ca10 (PO4)6 (OH)2 ), in composites and more recently, in fibrous composites formed using the electrospinning technique for bone tissue engineering applications. Calcium phosphate ceramics are sought because they can be bone bioactive, which means an apatite forms on their surface that facilitates bonding to bone tissue, and are osteoconductive. However, studies examining the bioactivity of electrospun composites containing calcium phosphates and their corresponding osteogenic activity have been limited. In this study, electrospun composites consisting of (20/80) HA/TCP nanoceramics and poly (ϵ-caprolactone) (PCL) were fabricated. Solvent and solvent combinations were evaluated to form scaffolds with a maximum concentration and dispersion of ceramic and pore sizes large enough for cell infiltration and tissue growth. PCL was dissolved in either methylene chloride (Composite-MC) or a combination of methylene chloride (80%) and dimethylformamide (20%; Composite-MC + DMF). Composites were evaluated in vitro for degradation, apatite formation, and osteogenic differentiation of human mesenchymal stem cells (MSCs) with an emphasis on temporal gene expression of osteogenic markers and the pluripotent gene Sox-2. Apatite formation and the osteogenic differentiation was the greatest for Composite-MC as determined by gene expression, protein production and biochemical markers, even without the presence of osteoinductive factors in the media, in comparison to Composite-MC + DMF and unfilled PCL mats. Sox-2 levels also reduced over time. The results of this study demonstrate that the solvent or solvent combination used in preparing the electrospun composite mats plays a critical role in determining their bioactivity which may, in turn, affect cell behavior. PMID:24264603

  11. Fungal Bioweathering of Mimetite and a General Geomycological Model for Lead Apatite Mineral Biotransformations

    PubMed Central

    Ceci, Andrea; Kierans, Martin; Hillier, Stephen; Persiani, Anna Maria

    2015-01-01

    Fungi play important roles in biogeochemical processes such as organic matter decomposition, bioweathering of minerals and rocks, and metal transformations and therefore influence elemental cycles for essential and potentially toxic elements, e.g., P, S, Pb, and As. Arsenic is a potentially toxic metalloid for most organisms and naturally occurs in trace quantities in soil, rocks, water, air, and living organisms. Among more than 300 arsenic minerals occurring in nature, mimetite [Pb5(AsO4)3Cl] is the most stable lead arsenate and holds considerable promise in metal stabilization for in situ and ex situ sequestration and remediation through precipitation, as do other insoluble lead apatites, such as pyromorphite [Pb5(PO4)3Cl] and vanadinite [Pb5(VO4)3Cl]. Despite the insolubility of mimetite, the organic acid-producing soil fungus Aspergillus niger was able to solubilize mimetite with simultaneous precipitation of lead oxalate as a new mycogenic biomineral. Since fungal biotransformation of both pyromorphite and vanadinite has been previously documented, a new biogeochemical model for the biogenic transformation of lead apatites (mimetite, pyromorphite, and vanadinite) by fungi is hypothesized in this study by application of geochemical modeling together with experimental data. The models closely agreed with experimental data and provided accurate simulation of As and Pb complexation and biomineral formation dependent on, e.g., pH, cation-anion composition, and concentration. A general pattern for fungal biotransformation of lead apatite minerals is proposed, proving new understanding of ecological implications of the biogeochemical cycling of component elements as well as industrial applications in metal stabilization, bioremediation, and biorecovery. PMID:25979898

  12. Fungal Bioweathering of Mimetite and a General Geomycological Model for Lead Apatite Mineral Biotransformations.

    PubMed

    Ceci, Andrea; Kierans, Martin; Hillier, Stephen; Persiani, Anna Maria; Gadd, Geoffrey Michael

    2015-08-01

    Fungi play important roles in biogeochemical processes such as organic matter decomposition, bioweathering of minerals and rocks, and metal transformations and therefore influence elemental cycles for essential and potentially toxic elements, e.g., P, S, Pb, and As. Arsenic is a potentially toxic metalloid for most organisms and naturally occurs in trace quantities in soil, rocks, water, air, and living organisms. Among more than 300 arsenic minerals occurring in nature, mimetite [Pb5(AsO4)3Cl] is the most stable lead arsenate and holds considerable promise in metal stabilization for in situ and ex situ sequestration and remediation through precipitation, as do other insoluble lead apatites, such as pyromorphite [Pb5(PO4)3Cl] and vanadinite [Pb5(VO4)3Cl]. Despite the insolubility of mimetite, the organic acid-producing soil fungus Aspergillus niger was able to solubilize mimetite with simultaneous precipitation of lead oxalate as a new mycogenic biomineral. Since fungal biotransformation of both pyromorphite and vanadinite has been previously documented, a new biogeochemical model for the biogenic transformation of lead apatites (mimetite, pyromorphite, and vanadinite) by fungi is hypothesized in this study by application of geochemical modeling together with experimental data. The models closely agreed with experimental data and provided accurate simulation of As and Pb complexation and biomineral formation dependent on, e.g., pH, cation-anion composition, and concentration. A general pattern for fungal biotransformation of lead apatite minerals is proposed, proving new understanding of ecological implications of the biogeochemical cycling of component elements as well as industrial applications in metal stabilization, bioremediation, and biorecovery.

  13. Novel contributions on luminescent apatite-based colloids intended for medical imaging.

    PubMed

    Al-Kattan, Ahmed; Santran, Veronique; Dufour, Pascal; Dexpert-Ghys, Jeannette; Drouet, Christophe

    2014-01-01

    The setup of colloidal hybrid nanosystems based on biomimetic calcium phosphate apatites doped with europium ions has recently raised great interest in the pharmacological community, especially due to their bio-inspired character. This is especially relevant in relation with medical imaging for cancer diagnosis. Questions however remain in relation to a number of applicability aspects, some of which have been examined in this contribution. In a first part of this work, we explored further the luminescence properties of such colloidal nanoparticles. We pointed out, upon excitation of europium, the existence of some non-radiative de-excitation via the vibration of O-H oscillators located at the vicinity of the Eu(3+) luminescent centers. The replacement of Eu(3+) by Tb(3+) ions, less prone to non-radiative de-excitation, was then tested in a preliminary way and can be seen as a promising alternative. In a second part of this work, we inspected the possibility to store these colloids in a dry state while retaining a re-suspension ability preserving the nanometer size of the initial nanoparticles, and we propose a functional protocol involving the addition of glucose prior to freeze-drying. We finally showed for the first time, based on titrations of intracellular Ca(2+) and Eu(3+) ions, that folic acid-functionalized biomimetic apatite nanoparticles were able to target cancer cells that overexpress folate receptors on their membrane, which we point out here in the case of T-47-D breast carcinoma cells, as opposed to ZR-75-1 cells that do not express folate receptors. This contribution thus opens new exciting perspectives in the field of targeted cancer diagnosis, thus confirming the promise of biomimetic apatites-based colloidal formulations.

  14. Effect of osteonectin-derived peptide on the viscoelasticity of hydrogel/apatite nanocomposite scaffolds.

    PubMed

    Sarvestani, Alireza S; He, Xuezhong; Jabbari, Esmaiel

    2007-03-01

    Hydrogel/apatite nanocomposites are the ideal biomaterial to mimic the physio-chemical and biologic properties of the bone and to fabricate scaffolds for bone regeneration. The objective of this work was to investigate the effect of an osteonectin derived glutamic acid sequence on the viscoelastic properties of poly(lactide-ethylene oxide-fumarate) (PLEOF)/apatite composite, as a model degradable material in bone regeneration. Osteonectin is an extracellular acidic glycoprotein of the bone matrix, which is believed to be involved in linking the collagen network to hydroxyapatite (HA), the mineral phase of the bone. We synthesized a 6-glutamic acid sequence in solid phase with affinity to HA crystals via ionic interactions. One end of the synthesized peptide was functionalized with an acrylate group to covalently attach the peptide (Ac-Glu6) to the aqueous-based biodegradable and in situ crosslinkable PLEOF hydrogel matrix. To determine the effect of energetic interactions between the fillers and hydrogel matrix, HA nanoparticles were also treated with an acrylate functionalized 6-glycine amino acid peptide (Ac-Gly6) that interacts with the fillers only by van der Waals and polar interactions (without ionic interactions). Crosslinked PLEOF/apatite scaffolds were prepared using PLEOF as the degradable macromer, HA nanofillers treated with Ac-Glu6 peptide linker, and a neutral redox initiation system. The viscoelastic properties were studied by dynamic time sweep, strain sweep, and small amplitude oscillatory rheometry. Composites without surface treatment, treated with Ac-Gly6, and treated with Ac-Glu6 at different volume fractions and various particle sizes were examined. The results showed that the 6-mer glutamic acid sequence significantly affects the shear modulus of the scaffold because of ionic interactions between the peptide and HA crystals.

  15. Effect of osteonectin-derived peptide on the viscoelasticity of hydrogel/apatite nanocomposite scaffolds.

    PubMed

    Sarvestani, Alireza S; He, Xuezhong; Jabbari, Esmaiel

    2007-03-01

    Hydrogel/apatite nanocomposites are the ideal biomaterial to mimic the physio-chemical and biologic properties of the bone and to fabricate scaffolds for bone regeneration. The objective of this work was to investigate the effect of an osteonectin derived glutamic acid sequence on the viscoelastic properties of poly(lactide-ethylene oxide-fumarate) (PLEOF)/apatite composite, as a model degradable material in bone regeneration. Osteonectin is an extracellular acidic glycoprotein of the bone matrix, which is believed to be involved in linking the collagen network to hydroxyapatite (HA), the mineral phase of the bone. We synthesized a 6-glutamic acid sequence in solid phase with affinity to HA crystals via ionic interactions. One end of the synthesized peptide was functionalized with an acrylate group to covalently attach the peptide (Ac-Glu6) to the aqueous-based biodegradable and in situ crosslinkable PLEOF hydrogel matrix. To determine the effect of energetic interactions between the fillers and hydrogel matrix, HA nanoparticles were also treated with an acrylate functionalized 6-glycine amino acid peptide (Ac-Gly6) that interacts with the fillers only by van der Waals and polar interactions (without ionic interactions). Crosslinked PLEOF/apatite scaffolds were prepared using PLEOF as the degradable macromer, HA nanofillers treated with Ac-Glu6 peptide linker, and a neutral redox initiation system. The viscoelastic properties were studied by dynamic time sweep, strain sweep, and small amplitude oscillatory rheometry. Composites without surface treatment, treated with Ac-Gly6, and treated with Ac-Glu6 at different volume fractions and various particle sizes were examined. The results showed that the 6-mer glutamic acid sequence significantly affects the shear modulus of the scaffold because of ionic interactions between the peptide and HA crystals. PMID:17183515

  16. Fungal Bioweathering of Mimetite and a General Geomycological Model for Lead Apatite Mineral Biotransformations.

    PubMed

    Ceci, Andrea; Kierans, Martin; Hillier, Stephen; Persiani, Anna Maria; Gadd, Geoffrey Michael

    2015-08-01

    Fungi play important roles in biogeochemical processes such as organic matter decomposition, bioweathering of minerals and rocks, and metal transformations and therefore influence elemental cycles for essential and potentially toxic elements, e.g., P, S, Pb, and As. Arsenic is a potentially toxic metalloid for most organisms and naturally occurs in trace quantities in soil, rocks, water, air, and living organisms. Among more than 300 arsenic minerals occurring in nature, mimetite [Pb5(AsO4)3Cl] is the most stable lead arsenate and holds considerable promise in metal stabilization for in situ and ex situ sequestration and remediation through precipitation, as do other insoluble lead apatites, such as pyromorphite [Pb5(PO4)3Cl] and vanadinite [Pb5(VO4)3Cl]. Despite the insolubility of mimetite, the organic acid-producing soil fungus Aspergillus niger was able to solubilize mimetite with simultaneous precipitation of lead oxalate as a new mycogenic biomineral. Since fungal biotransformation of both pyromorphite and vanadinite has been previously documented, a new biogeochemical model for the biogenic transformation of lead apatites (mimetite, pyromorphite, and vanadinite) by fungi is hypothesized in this study by application of geochemical modeling together with experimental data. The models closely agreed with experimental data and provided accurate simulation of As and Pb complexation and biomineral formation dependent on, e.g., pH, cation-anion composition, and concentration. A general pattern for fungal biotransformation of lead apatite minerals is proposed, proving new understanding of ecological implications of the biogeochemical cycling of component elements as well as industrial applications in metal stabilization, bioremediation, and biorecovery. PMID:25979898

  17. Early apatite deposition and osteoblast growth on plasma-sprayed dicalcium silicate coating.

    PubMed

    Liu, Xuanyong; Xie, Youtao; Ding, Chuanxian; Chu, Paul K

    2005-09-01

    Dicalcium silicate coating was deposited onto a Ti-6Al-4V substrate using plasma-spraying technology. The coating was immersed in simulated body fluid (SBF) for 1, 3, 6, 12, 24, and 48 h to investigate early apatite formation on the coating. Osteoblasts were also seeded onto the surface of the dicalcium silicate coating to evaluate its biocompatibility. Cold field-emission scanning electron microscopy and energy-dispersive X-ray spectrometry were used to evaluate the morphologies and determine the chemical composition of the coatings. The surface structural changes caused by immersion in SBF were analyzed using thin-film X-ray diffraction. After the dicalcium silicate coating was soaked in SBF solution 1-6 h, two types of particles containing calcium and phosphorus were formed on the surface. One type consisted of relatively larger particles (P1) precipitated on the surface of the coating from the precursor cluster formed in the SBF solution. The second type was composed of particles (P2) nucleated on the surface of the coating. With increasing immersion time, the particles coalesced to form a surface Ca-P layer. The Ca-P layer was composed of amorphous calcium phosphate that was not transformed to crystalline apatite until the immersion time in SBF exceeded 24 h. The formation mechanism of the Ca-P layer and apatite on the surface of the coating is believed to be involved in the formation of the Si 3-ring active surface site with negative charge. The cell-seeding test revealed that osteoblasts grew and proliferated very well on the surface of the dicalcium silicate coating.

  18. Thermodynamic Properties of Sulfatian Apatite: Constraints on the Behavior of Sulfur in Calc-Alkaline Magmas

    NASA Astrophysics Data System (ADS)

    Core, D.; Essene, E. J.; Luhr, J. F.; Kesler, S. E.

    2004-12-01

    The Gibbs free energy of hydroxyellestadite [Ca10(SiO4)3(SO4)3(OH)2] was estimated using mineral equilibria applied to analyzed assemblages from the experimental charges of Luhr (1990). The apatite analyses of Peng et al. (1997) were used in conjunction with new analyses of the oxides and silicates in this study. An ideal mixing model was employed for apatite combined with mixing models from MELTS (Ghiorso & Sack, 1994) and Gibbs free energy data from Robie & Hemingway (1995) for the other crystalline phases. The resultant equation of the Gibbs free energy vs. T for hydroxyellestadite is as follows: DG°T(elem) = [2.817(T - 273) - 11831]/1000 kJ/mol, T in K. The calculated entropy for hydroxyellestadite is 1944 J/mol.K at 1073 K and 2151 J/mol.K at 1227 K. Independent estimates of the entropy of hydroxyellestadite obtained with the method of Robinson & Haas (1983) are within 5% of these values. The thermodynamic data on hydroxyellestadite were used to calculate the locus of the reactions: 2Ca10(SiO4)3(SO4)3(OH)2 + 7S2 + 21O2 = 20CaSO4 + 6SiO2 + 2H2O 6Ca10(SiO4)3(SO4)3(OH)2 + 102SiO2 + 20Fe3O4 = 60CaFeSi2O6 + 6H2O + 9S2 + 37O2 2Ca10(SiO4)3(SO4)3(OH)2 + 10Mg2Si2O6 + 14SiO2 = 20CaMgSi2O6 + 2H2O + 3S2 + 9O2 in fO2-fS2 space at fixed P-T. Application of these equilibria to apatite zoned in sulfate from oxidized granitoids reflects a drop in fS2 by more than 1 log unit during its growth. The zoning is interpreted to represent the removal of a magmatic vapor phase during crystallization of these plutons. Removal of sulfur from magmas by hydrothermal fluids is important to the ore-forming process and to the production of acid sulfate aerosols during eruption of oxidized magmas. Preservation of sulfatian apatite may yield data on the sulfidation states of ancient flood basalts such as the Deccan Traps of India and the Parana basalts of Brazil to address the environmental impact of these giant eruptions.

  19. Crystal chemical characteristics of ellestadite-type apatite: implications for toxic metal immobilization.

    PubMed

    Fang, Y N; Ritter, Clemens; White, T J

    2014-11-14

    The ellestadite apatites Ca10[(SiO4)x(PO4)6-2x(SO4)x]Cl2 were studied by powder X-ray and neutron diffraction to establish baseline crystallographic data. These synthetic materials, unlike mineral specimens that are well equilibrated, show no Si/P/S ordering and conform to P63/m symmetry. Phosphate-rich ellestadites where 0 ≤ x ≤ 1 show chemical stability towards Toxicity Characterization Leaching Procedure (TCLP) testing and are potential immobilization matrices for mixed toxic metal wastes.

  20. In-Situ Apatite Laser Ablation U-Th-Sm/He Dating, Methods and Challenges

    NASA Astrophysics Data System (ADS)

    Pickering, J. E.; Matthews, W.; Guest, B.; Hamilton, B.; Sykes, C.

    2015-12-01

    In-situ, laser ablation U-Th-Sm/He dating is an emerging technique in thermochronology that has been proven as a means to date zircon and monzonite1-5. In-situ U-Th-Sm/He thermochronology eliminates many of the problems and inconveniences associated with traditional, whole grain methods, including; reducing bias in grain selection based on size, shape and clarity; allowing for the use of broken grains and grains with inclusions; avoiding bad neighbour effects; and eliminating safety hazards associated with dissolution. In-situ apatite laser ablation is challenging due to low concentrations of U and Th and thus a low abundance of radiogenic He. For apatite laser ablation to be effective the ultra-high-vacuum (UHV) line must have very low and consistent background levels of He. To reduce He background, samples are mounted in a UHV stable medium. Our mounting process uses a MicroHePP (Microscope Mounted Heated Platen Press) to press samples into FEP (fluorinated ethylene propylene) bonded to an aluminum backing plate. Samples are ablated using a Resonetics 193 nm excimer laser and liberated He is measured using a quadrupole mass spectrometer on the ASI Alphachron noble gas line; collectively this system is known as the Resochron. The ablated sites are imaged using a Zygo Zescope optical profilometer and ablated pit volume measured using PitVol, a custom MatLab algorithm developed to enable precise and unbiased measurement of the ablated pit geometry. We use the well-characterized Durango apatite to demonstrate the accuracy and precision of the method. He liberated from forty-two pits, having volumes between 1700 and 9000 um3, were measured using the Resochron. The ablated sites were imaged using a Zygo Zescope optical profilometer and ablated pit volume measured using PitVol. U, Th and Sm concentrations were measured by laser ablation and the U-Th-Sm/He age calculated by standard age equation. An age of 33.8±0.31 Ma was determined and compares well with conventional

  1. Soft-tissue augmentation with hyaluronic acid and calcium hydroxyl apatite fillers.

    PubMed

    Redbord, Kelley Pagliai; Busso, Mariano; Hanke, C William

    2011-01-01

    Soft-tissue augmentation with hyaluronic acid and calcium hydroxyl apatite are among the most widely used minimally invasive cosmetic treatments for the correction of contour deficiencies and wrinkles of the face without the risk, recovery time, and expense of a major surgery. Training and experience in the art and science of fillers is essential for the successful creation of a more youthful and natural appearance. An understanding of the different products, the injection techniques, the indications, and the potential complications of each filler are paramount to success.

  2. Extraction of rare earth elements from hydrate-phosphate precipitates of apatite processing

    NASA Astrophysics Data System (ADS)

    Andropov, M. O.; Anufrieva, A. V.; Buynovskiy, A. S.; Makaseev, Y. N.; Mazov, I. N.; Nefedov, R. A.; Sachkov, V. I.; Stepanova, O. B.; Valkov, AV

    2016-01-01

    The features of extraction of rare earth elements (REE) were considered from hydrate-phosphate precipitates of REE of apatite processing by nitric acid technology. The preliminary purification of nitrate solution of REE from impurities of titanium, aluminum, iron, uranium and thorium was suggested to obtain stable solutions not forming precipitates. Washing the extract was recommended with the evaporated reextract that allows to obtain directly on the cascade of REE extraction the concentrated solutions suitable for the separation into groups by the extraction method. Technical decisions were suggested for the separation of REE in groups without the use of salting-out agent.

  3. Frequency of dementia syndromes with a potentially treatable cause in geriatric in-patients: analysis of a 1-year interval.

    PubMed

    Djukic, Marija; Wedekind, Dirk; Franz, Almuth; Gremke, Melanie; Nau, Roland

    2015-08-01

    In addition to neurodegenerative and vascular causes of dementia, in the differential diagnosis potentially reversible conditions of dementia also must be assessed. Routine laboratory parameters and neuroimaging, which are recommended for the differential diagnosis of suspected dementia by the German S3 Guideline "Dementia", were retrospectively studied in 166 geriatric patients with suspected dementia. Delirium was diagnosed in six patients (3.6%). These six patients were excluded from the study. Of the 160 remaining patients, there were 99 (59.6%) with an already known dementia. In this subgroup of patients, we found a potentially treatable cause of dementia in 18.2%. In the remaining 61 patients (36.8%), the newly diagnosed dementia syndrome was established according to ICD-10 criteria. Potentially reversible causes of the dementia syndrome were found in 19 of these patients (31.1%). The most common cause was depressive pseudodementia in eight patients followed by vitamin B12 deficiency in six patients. A significant amount of our patients showed laboratory or imaging changes suggestive of potentially reversible causes of the dementia syndrome upon admission. The results of our study indicate the importance of careful differential diagnosis of dementia based on the recommendations of guidelines. Although therapy of these potential causes is not always accompanied by a full recovery, the identification and therapy of treatable causes of cognitive deficits are possible even for general practitioners, who often are the primary contact persons of affected individuals. PMID:25716929

  4. Apatite fission-track thermochronology of the Appalachian foreland basin from the Virginia Piedmont to eastern Ohio

    SciTech Connect

    Roden, M.K. . Dept. of Earth and Environmental Science); Cerveny, P.F.; Bergman, S.C. . Research and Technical Services)

    1992-01-01

    Apatite fission-track ages have been determined for 29 samples from two transects in the southern Appalachians. The northern transect extends from the VA Piedmont northwest through the Valley and Ridge Province, Cumberland Plateau, and into the Appalachian foreland of southeastern OH. An additional transect was collected from the Pine Mountain thrust in southeastern KY extending northwest to the Cincinnati Arch. Precambrian gneisses and granites from the VA Piedmont yield reset apatite fission-track ages ranging from 103 [+-] 6 to 138 [+-] 11 Ma. Ordovician through Mississippian sedimentary rocks from the Valley and Ridge Province of VA-WV also yield reset apatite fission-track ages ranging from 120 [+-] 8 to 144 [+-] 20 Ma. The cooling histories for the Piedmont and Valley and Ridge rocks of VA and WV thus appear similar, having cooled rapidly between about 103 and 144 Ma. Pennsylvanian samples from the Cumberland Plateau of WV yield rest apatite fission-track ages of 112 [+-] 7 to 169 [+-] 13 MA in the southeast which grade into partially reset (mixed ages) northwest of Charlestown (133 [+-] 13 to 156 [+-] 10 Ma). The Permian Dunkard Formation from the OH-WV border yielded a mixed age of 197 [+-] 13 Ma, suggesting that the Permian has not been subjected to temperatures > 100 C for times greater than 1 Ma, since it was deposited. Mississippian--Pennsylvanian samples from eastern KY yield reset apatite fission-track ages which decrease from the Pine Mt. Thrust (186 [+-] 16 Ma) to Mozelle, KY (136 [+-] 12 Ma), then increase toward the Cincinnati Arch (166 [+-] 18 [minus] 186 [+-] 21 Ma). This is consistent with older apatite fission-track ages (200 Ma) from Ordovician K-bentonites in the vicinity of the Cincinnati Arch.

  5. Possible secondary apatite fission track age standard from altered volcanic ash beds in the middle Jurassic Carmel Formation, Southwestern Utah

    USGS Publications Warehouse

    Kowallis, B.J.; Christiansen, E.H.; Everett, B.H.; Crowley, K.D.; Naeser, C.W.; Miller, D.S.; Deino, A.L.

    1993-01-01

    Secondary age standards are valuable in intra- and interlaboratory calibration. At present very few such standards are available for fission track dating that is older than Tertiary. Several altered volcanic ash beds occur in the Middle Jurassic Carmel Formation in southwestern Utah. The formation was deposited in a shallow marine/sabhka environment. Near Gunlock, Utah, eight ash beds have been identified. Sanidines from one of the ash beds (GUN-F) give a single-crystal laser-probe 40Ar/39Ar age of 166.3??0.8 Ma (2??). Apatite and zircon fission track ages range from 152-185 Ma with typically 15-20 Ma errors (2??). Track densities in zircons are high and most grains are not countable. Apatites are fairly common in most of the ash beds and have reasonable track densities ranging between 1.2-1.5 ?? 106 tracks/cm2. Track length distributions in apatites are unimodal, have standard deviations <1??m, and mean track lengths of about 14-14.5 ??m. High Cl apatites (F:Cl:OH ratio of 39:33:28) are particularly abundant and large in ash GUN-F, and are fairly easy to concentrate, but the concentrates contain some siderite, most of which can be removed by sieving. GUN-F shows evidence of some reworking and detriaal contamination based on older single grain 40Ar/39Ar analyses and some rounding of grains, but the apatite population appears to be largely uncontaminated. At present BJK has approximately 12 of apatite separate from GUN-F. ?? 1993.

  6. Lattice energies of apatites and the estimation of DeltaH f degrees (PO 4 3-, g).

    PubMed

    Flora, Natalie J; Yoder, Claude H; Jenkins, H Donald Brooke

    2004-04-01

    Experimentally based lattice energies are calculated for the apatite family of double salts M(5)(PO(4))(3)X, where M is a divalent metal cation (Ca, Sr, Ba) and X is hydroxide or a halide. These values are also shown to be estimable, generally to within 4%, using the recently derived Glasser-Jenkins equation, U(POT) = AI(2I/V(m))(1/3), where A = 121.39 kJ mol(-)(1). The apatites exhibiting greater covalent character (e.g., M = Pb, Cd, etc.) are less well reproduced but are within 8% of the experimentally based value. The lattice energy for ionic apatites (having identical lattice ionic strengths, I) takes the particularly simple form U(POT)/kJ mol(-)(1) = 26680/(V(m)/nm(3))(1/3), reproducing cycle values of U(POT) well when V(m) is estimated by ion volume summation and employing a volume for the PO(4)(3)(-) ion (not previously quantified with an associated error) of 0.063 +/- 0.003 nm(3). A value for the enthalpy of formation of the gaseous phosphate ion, DeltaH(f)( ) degrees (PO(4)(3)(-), g), is absent from current thermochemical tabulations. Examination of solution and solid state thermochemical cycles for apatites, however, leads us to a remarkably consistent value of 321.8 +/- 1.2 kJ mol(-)(1). Experimental and estimated lattice energies were used along with other thermodynamic data to determine enthalpies, entropies, and free energies of dissolution for apatites of uncertain stabilities. These dissolution values are compared with the corresponding values for stable apatites and are used to rationalize the relative instability of certain derivatives.

  7. Biomimetic growth and substrate dependent mechanical properties of bone like apatite nucleated on Ti and magnetron sputtered TiO2 nanostructure

    NASA Astrophysics Data System (ADS)

    Sarma, Bimal K.; Das, Apurba; Barman, Pintu; Pal, Arup R.

    2016-04-01

    This report presents findings on biomimetic growth of hydroxyapatite (HAp) nanocrystals on Ti and sputtered TiO2 substrates. The possibility of TiO2 nanostructure as candidate materials for future biomedical applications has been explored through the comparison of microstructural and mechanical properties of bone like apatite grown on Ti and nano-TiO2 surfaces. Raman spectroscopy and x-ray diffraction studies reveal formation of carbonate apatite with apparent domain size in the nanoscale range. A better interaction at the nano-TiO2/nano-HAp interface due to higher interfacial area could promote the growth of bone like apatite. The crystal phases, crystallinity, and surface morphology of nano-TiO2 are considered as parameters to understand the nucleation and growth of apatite with different mechanical properties at the nanoscale. The methodology of x-ray line profile analysis encompasses deconvolution of merged peaks by preserving broadening due to nanosized HAp aggregates. The Young’s modulus of bone like apatite exhibits crystallographic directional dependence which suggests the presence of elastic anisotropy in bone like apatite. The lattice contraction in the c-direction is associated with the degree of carbonate substitution in the apatite lattice. The role of residual stress is critical for the lattice distortion of HAp deposited at physiological conditions of temperature and pH of human blood plasma. The ion concentration is crucial for the uniformity, crystallinity, and mechanical behaviour of the apatite.

  8. Gelatin-apatite bone mimetic co-precipitates incorporated within biopolymer matrix to improve mechanical and biological properties useful for hard tissue repair

    PubMed Central

    Won, Jong-Eun; El-Fiqi, Ahmed; Jegal, Seung-Hwan; Han, Cheol-Min; Lee, Eun-Jung; Knowles, Jonathan C

    2014-01-01

    Synthetic biopolymers are commonly used for the repair and regeneration of damaged tissues. Specifically targeting bone, the composite approach of utilizing inorganic components is considered promising in terms of improving mechanical and biological properties. We developed gelatin-apatite co-precipitates which mimic the native bone matrix composition within poly(lactide-co-caprolactone) (PLCL). Ionic reaction of calcium and phosphate with gelatin molecules enabled the co-precipitate formation of gelatin-apatite nanocrystals at varying ratios. The gelatin-apatite precipitates formed were carbonated apatite in nature, and were homogeneously distributed within the gelatin matrix. The incorporation of gelatin-apatite significantly improved the mechanical properties, including tensile strength, elastic modulus and elongation at break, and the improvement was more pronounced as the apatite content increased. Of note, the tensile strength increased to as high as 45 MPa (a four-fold increase vs. PLCL), the elastic modulus was increased up to 1500 MPa (a five-fold increase vs. PLCL), and the elongation rate was ∼240% (twice vs. PLCL). These results support the strengthening role of the gelatin-apatite precipitates within PLCL. The gelatin-apatite addition considerably enhanced the water affinity and the acellular mineral-forming ability in vitro in simulated body fluid; moreover, it stimulated cell proliferation and osteogenic differentiation. Taken together, the GAp-PLCL nanocomposite composition is considered to have excellent mechanical and biological properties, which hold great potential for use as bone regenerative matrices. PMID:23985536

  9. Apatite as an indicator of fluid salinity: An experimental study of chlorine and fluorine partitioning in subducted sediments

    NASA Astrophysics Data System (ADS)

    Li, Huijuan; Hermann, Joerg

    2015-10-01

    In order to constrain the salinity of subduction zone fluids, piston-cylinder experiments have been conducted to investigate the partitioning behaviour of Cl and F in subducted sediments. These experiments were performed at H2O-undersaturated conditions with a synthetic pelite starting composition containing 800 ppm Cl, over a pressure and temperature range of 2.5-4.5 GPa and 630-900 °C. Repetitive experiments were conducted with 1900 ppm Cl + 1000 ppm F, and 2100 ppm Cl. Apatite represents the most Cl-abundant mineral phase, with Cl concentration varying in the range 0.1-2.82 wt%. Affinity for Cl decreases over the following sequence: aqueous fluid > apatite ⩾ melt > other hydrous minerals (phengite, biotite and amphibole). It was found that addition of F to the Cl-bearing starting composition significantly lowers the Cl partition coefficients between apatite and melt (DClAp-melt) and apatite and aqueous fluid (DClAp-aq). Cl-OH exchange coefficients between apatite and melt (KdCl-OHAp-melt) and apatite and aqueous fluid (KdCl-OHAp-aq) were subsequently calculated. KdCl-OHAp-melt was found to vary from 1 to 58, showing an increase with temperature and a decrease with pressure and displaying a regular decrease with increasing H2O content in melt. Mole fractions of Cl and OH in melt were calculated based on an ideal mixing model for H2O, OH, O, Cl and F. The Cl contents of other hydrous minerals (phengite, biotite and amphibole) fall between 200 and 800 ppm, with resultant Cl partition coefficients from 0.02 to 0.49, appearing independent of the bulk Cl and F content. Preliminary data from this study show that the partitioning behaviour of F is strongly in favour of apatite relative to melt and phengite, with DFAp-melt = 15-51. Apatites from representative eclogite facies metasediments were examined and found to have low Cl contents close to ∼100 ppm. Calculations using our experimentally determined KdCl-OHAp-aq of 0.004 at 2.5 GPa, 630 °C indicate a low

  10. Calibration of the Fluorine, Chlorine and Hydrogen Content of Apatites With the ChemCam LIBS Instrument

    NASA Technical Reports Server (NTRS)

    Meslin, P.-Y.; Cicutto, L.; Forni, O.; Drouet, C.; Rapin, W.; Nachon, M.; Cousin, A.; Blank, J. G.; McCubbin, F. M.; Gasnault, O.; Newsom, H.; Mangold, N.; Schroeder, S.; Sautter, V.; Maurice, S.; Wiens, R. C.

    2016-01-01

    Determining the composition of apatites is important to understand the behavior of volatiles during planetary differentiation. Apatite is an ubiquitous magmatic mineral in the SNC meteorites. It is a significant reservoir of halogens in these meteorites and has been used to estimate the halogen budget of Mars. Apatites have been identified in sandstones and pebbles at Gale crater by ChemCam, a Laser-Induced Breakdown Spectroscometer (LIBS) instrument onboard the Curiosity rover. Their presence was inferred from correlations between calcium, fluorine (using the CaF molecular band centered near 603 nm, whose detection limit is much lower that atomic or ionic lines and, in some cases, phosphorus (whose detection limit is much larger). An initial quantification of fluorine, based on fluorite (CaF2)/basalt mixtures and obtained at the LANL laboratory, indicated that the excess of F/Ca (compared to the stoichiometry of pure fluorapatites) found on Mars in some cases could be explained by the presence of fluorite. Chlorine was not detected in these targets, at least above a detection limit of 0.6 wt% estimated from. Fluorapatite was later also detected by X-ray diffraction (with CheMin) at a level of approx.1wt% in the Windjana drill sample (Kimberley area), and several points analyzed by ChemCam in this area also revealed a correlation between Ca and F. The in situ detection of F-rich, Cl-poor apatites contrasts with the Cl-rich, F-poor compositions of apatites found in basaltic shergottites and in gabbroic clasts from the martian meteorite NWA 7034, which were also found to be more Cl-rich than apatites from basalts on Earth, the Moon, or Vesta. The in situ observations could call into question one of the few possible explanations brought forward to explain the SNC results, namely that Mars may be highly depleted in fluorine. The purpose of the present study is to refine the calibration of the F, Cl, OH and P signals measured by the ChemCam LIBS instrument, initiated

  11. Carbonate-containing apatite (CAP) synthesis under moderate conditions starting from calcium carbonate and orthophosphoric acid.

    PubMed

    Pham Minh, Doan; Tran, Ngoc Dung; Nzihou, Ange; Sharrock, Patrick

    2013-07-01

    The synthesis of carbonate-containing apatite (CAP) from calcium carbonate and orthophosphoric acid under moderate conditions was investigated. In all cases, complete precipitation of orthophosphate species was observed. The reaction temperature influenced strongly the decomposition of calcium carbonate and therefore the composition of formed products. The reaction temperature of 80 °C was found to be effective for the complete decomposition of calcium carbonate particles after 48 h of reaction. Infra-red spectroscopy (IR), nuclear magnetic resonance (NMR), thermogravimetry/mass spectroscopy (TG-MS) coupling, and X-ray diffraction (XRD) characterizations allowed the identification of the composition of formed products. By increasing the reaction temperature from 20 °C to 80 °C, the content of A-type CAP increased and that of B-type CAP decreased, according to the favorable effect of temperature on the formation of A-type CAP. The total amount of carbonate content incorporated in CAP's structure, which was determined by TG-MS analysis, increased with the reaction temperature and reached up to 4.1% at 80 °C. At this temperature, the solid product was mainly composed of apatitic components and showed the typical flat-needle-like structure of CAP particles obtained in hydrothermal conditions. These results show an interesting one-step synthesis of CAP from calcium carbonate and orthophosphoric acid as low cost but high purity starting materials.

  12. Chemical Composition Determination Of Francolite Apatites By Fourier Transform Infrared (FTIR) Spectroscopy

    NASA Astrophysics Data System (ADS)

    Scheib, Robin M.; Thrasher, Raymond D.; Lehr, James R.

    1981-10-01

    Prior work by Lehr and McClellan and Lehr, based on chemical, crystallographic, and x-ray diffraction studies, showed the relationship between phosphate (P) and substituted carbonate (C) in francolite apatite to be P+C = 6.00 ± 0.04 and the generalized apatite formula to be (Ca,Na,Mg) 10(PO4)6-x(CO3)xFy(F,OH)2, in which y ranges from 0.33x to 0.5x. Using the FTIR, the ratio of the area of the absorption curve for C-0 (bands in the region 1375 to 1550 cm-1) versus the area of the absorption curve for P-0 (bands in the region 530 to 690 cm-1), the "CO2 index," was found to be proportional to the mole ratio of CO3:PO4 in francolites. Stripping methods allowed the subtraction of spectral contributions of silicate and carbonate minerals and water, which would ordinarily interfere with such a determination. The study was based on 65 mineral samples and the formula was found to be: CO2 index = 0.0678 + 4.184(mole ratio CO3:PO4) (1) The correlation factor, r2, was 0.938 and the standard error of the slope ±0.136. The probability of the null hypothesis for the model was less than 0.0001.

  13. The role of intracellular calcium phosphate in osteoblast-mediated bone apatite formation.

    PubMed

    Boonrungsiman, Suwimon; Gentleman, Eileen; Carzaniga, Raffaella; Evans, Nicholas D; McComb, David W; Porter, Alexandra E; Stevens, Molly M

    2012-08-28

    Mineralization is a ubiquitous process in the animal kingdom and is fundamental to human development and health. Dysfunctional or aberrant mineralization leads to a variety of medical problems, and so an understanding of these processes is essential to their mitigation. Osteoblasts create the nano-composite structure of bone by secreting a collagenous extracellular matrix (ECM) on which apatite crystals subsequently form. However, despite their requisite function in building bone and decades of observations describing intracellular calcium phosphate, the precise role osteoblasts play in mediating bone apatite formation remains largely unknown. To better understand the relationship between intracellular and extracellular mineralization, we combined a sample-preparation method that simultaneously preserved mineral, ions, and ECM with nano-analytical electron microscopy techniques to examine osteoblasts in an in vitro model of bone formation. We identified calcium phosphate both within osteoblast mitochondrial granules and intracellular vesicles that transported material to the ECM. Moreover, we observed calcium-containing vesicles conjoining mitochondria, which also contained calcium, suggesting a storage and transport mechanism. Our observations further highlight the important relationship between intracellular calcium phosphate in osteoblasts and their role in mineralizing the ECM. These observations may have important implications in deciphering both how normal bone forms and in understanding pathological mineralization.

  14. The nano-morphological relationships between apatite crystals and collagen fibrils in ivory dentine.

    PubMed

    Jantou-Morris, V; Horton, Michael A; McComb, David W

    2010-07-01

    In this work, analytical transmission electron microscopy (TEM) was used to study the nanostructure of mineralised ivory dentine, in order to gain a clearer understanding of the relationship between the organic (collagen fibrils) and inorganic (calcium phosphate apatite crystals) components. Thin sections prepared by both focused ion beam (FIB) milling and ultramicrotomy, in the longitudinal and transverse planes, were investigated using electron energy-loss spectroscopy (EELS) in a monochromated field-emission gun scanning TEM (FEI Titan 80-300 FEGSTEM). Both low- and core-loss spectroscopy were used in the investigation, and the signals from phosphorous, carbon, calcium, nitrogen and oxygen were studied in detail. A combination of HAADF (high-angle annular dark-field)-STEM imaging and EELS analysis was used for simultaneous acquisition of both spatial and spectral information pixel by pixel (spectrum imaging). Across the collagen D banding in longitudinal sections, the relative thickness of the bright bands was significantly higher than that of the dark bands. Core-loss spectroscopy showed that the bright bands were richer in apatite than the dark bands. However, no ELNES variation was observed across the D banding. In transverse sections, significant changes in the carbon edge fine structure were observed at the interface between the extra- and intra-fibrillar regions.

  15. Synthesis and characterization of nanocrystalline apatites from solution modeling human blood

    NASA Astrophysics Data System (ADS)

    Solodyankina, Anna; Nikolaev, Anton; Frank-Kamenetskaya, Olga; Golovanova, Olga

    2016-09-01

    Present paper is devoted to the research of the calcification processes in the blood plasma of human body. Spontaneous crystallization from the solution modeling the inorganic part of the blood plasma has been carried out. Obtained precipitates were studied by the various instrumental methods (X-ray powder diffraction, Fourier-transformed infrared spectroscopy, scanning electron microscopy, electron probe microanalysis and gas-volumetric method). All gathered data allow to summarize that nonstoichiometric carbonated hydroxyapatite with low crystallinity (CSD lengths 18-28 nm), high water content and small amount of chlorine ion was obtained throughout the syntheses. Part of vacancies at the Ca sites varies from 0.17 to 0.87; the value of the Cat/(P + C) ratio-from 1.52 to 1.64 (where Cat = Ca2+ + Na+ + K+ + Mg2+). The poor crystallized synthetic apatites with high carbonate ion content (from 4.34 to 5.54 wt%) and c parameter (6.888-6.894 Å) are analogues of the apatites of the pathological cardiovascular deposits. They can be obtained from the solution modeling human blood plasma by the inorganic components with calcium phosphate supersaturation 25 and 50 and with 10 and 12 weeks experiment time.

  16. The role of intracellular calcium phosphate in osteoblast-mediated bone apatite formation

    PubMed Central

    Boonrungsiman, Suwimon; Gentleman, Eileen; Carzaniga, Raffaella; Evans, Nicholas D.; McComb, David W.; Porter, Alexandra E.; Stevens, Molly M.

    2012-01-01

    Mineralization is a ubiquitous process in the animal kingdom and is fundamental to human development and health. Dysfunctional or aberrant mineralization leads to a variety of medical problems, and so an understanding of these processes is essential to their mitigation. Osteoblasts create the nano-composite structure of bone by secreting a collagenous extracellular matrix (ECM) on which apatite crystals subsequently form. However, despite their requisite function in building bone and decades of observations describing intracellular calcium phosphate, the precise role osteoblasts play in mediating bone apatite formation remains largely unknown. To better understand the relationship between intracellular and extracellular mineralization, we combined a sample-preparation method that simultaneously preserved mineral, ions, and ECM with nano-analytical electron microscopy techniques to examine osteoblasts in an in vitro model of bone formation. We identified calcium phosphate both within osteoblast mitochondrial granules and intracellular vesicles that transported material to the ECM. Moreover, we observed calcium-containing vesicles conjoining mitochondria, which also contained calcium, suggesting a storage and transport mechanism. Our observations further highlight the important relationship between intracellular calcium phosphate in osteoblasts and their role in mineralizing the ECM. These observations may have important implications in deciphering both how normal bone forms and in understanding pathological mineralization. PMID:22879397

  17. Microwave assisted apatite coating deposition on Ti6Al4V implants.

    PubMed

    Zhou, Huan; Nabiyouni, Maryam; Bhaduri, Sarit B

    2013-10-01

    In this work we report a novel microwave assisted technology to deposit a uniform, ultra-thin apatite coating without any cracks on titanium implants in minutes. This method comprises of conventional biomimetic coating in synergism with microwave irradiation to result in alkaline earth phosphate nucleation. The microwave assisted coating process mainly follows the initial stages of biomimetic coating until the step of the Ca-P nuclei formation. After that, due to microwave irradiation more Ca-P nuclei are formed to cover the whole surface of the implant instead of the growth of deposited Ca-P nuclei to Ca-P globules and coatings. It is interesting to note the doping of Mg(2+) to Ca-P apatite coating can significantly change the properties and performances of as-deposited coatings. The hydrophilicity, physical properties, bioactivity, cell adhesion, and growth capability of as-deposited microwave assisted coatings were investigated. The study shows that this coating technology has great potential in biomedical applications. Additionally, since biomimetic coating can be applied to series of implant materials such as polymer, metals and glass, it is expected this microwave assisted coating technology can also be applied to these materials if they can remains stable at 100 °C, the boiling point of water.

  18. A first report of hydroxylated apatite as structural biomineral in Loasaceae - plants' teeth against herbivores.

    PubMed

    Ensikat, Hans-Jürgen; Geisler, Thorsten; Weigend, Maximilian

    2016-01-01

    Biomineralization provides living organisms with various materials for the formation of resilient structures. Calcium phosphate is the main component of teeth and bones in vertebrates, whereas especially silica serves for the protection against herbivores on many plant surfaces. Functional calcium phosphate structures are well-known from the animal kingdom, but had not so far been reported from higher plants. Here, we document the occurrence of calcium phosphate biomineralization in the South-American plant group Loasaceae (rock nettle family), which have stinging trichomes similar to those of the well-known stinging nettles (Urtica). Stinging hairs and the smaller, glochidiate trichomes contained nanocrystalline hydroxylated apatite, especially in their distal portions, replacing the silica found in analogous structures of other flowering plants. This could be demonstrated by chemical, spectroscopic, and diffraction analyses. Some species of Loasaceae contained both calcium phosphate and silica in addition to calcium carbonate. The intriguing discovery of structural hydroxylated apatite in plants invites further studies, e.g., on its systematic distribution across the family, the genetic and cellular control of plant biomineralization, the properties and ultrastructure of calcium phosphate. It may prove the starting point for the development of biomimetic calcium phosphate composites based on a cellulose matrix. PMID:27194462

  19. Histological Comparison in Rats between Carbonate Apatite Fabricated from Gypsum and Sintered Hydroxyapatite on Bone Remodeling

    PubMed Central

    Ayukawa, Yasunori; Suzuki, Yumiko; Tsuru, Kanji; Koyano, Kiyoshi; Ishikawa, Kunio

    2015-01-01

    Carbonate apatite (CO3Ap), the form of apatite found in bone, has recently attracted attention. The purpose of the present study was to histologically evaluate the tissue/cellular response toward the low-crystalline CO3Ap fabricated using a dissolution-precipitation reaction with set gypsum as a precursor. When set gypsum was immersed in a 100°C 1 mol/L Na3PO4 aqueous solution for 24 h, the set gypsum transformed into CO3Ap. Both CO3Ap and sintered hydroxyapatite (s-HAp), which was used as a control, were implanted into surgically created tibial bone defects of rats for histological evaluation. Two and 4 weeks after the implantation, histological sections were created and observed using light microscopy. The CO3Ap granules revealed both direct apposition of the bone matrix by osteoblasts and osteoclastic resorption. In contrast, the s-HAp granules maintained their contour even after 4 weeks following implantation which implied that there was a lack of replacement into the bone. The s-HAp granules were sometimes encapsulated with fibrous tissue, and macrophage polykaryon was occasionally observed directly apposed to the implanted granules. From the viewpoint of bone remodeling, the CO3Ap granules mimicked the bone matrix, suggesting that CO3Ap may be an appropriate bone substitute. PMID:26504813

  20. Interstitial Oxide Ion Distribution and Transport Mechanism in Aluminum-Doped Neodymium Silicate Apatite Electrolytes.

    PubMed

    An, Tao; Baikie, Tom; Orera, Alodia; Piltz, Ross O; Meven, Martin; Slater, Peter R; Wei, Jun; Sanjuán, María L; White, T J

    2016-04-01

    Rare earth silicate apatites are one-dimensional channel structures that show potential as electrolytes for solid oxide fuel cells (SOFC) due to their high ionic conductivity at intermediate temperatures (500-700 °C). This advantageous property can be attributed to the presence of both interstitial oxygen and cation vacancies, that create diffusion paths which computational studies suggest are less tortuous and have lower activation energies for migration than in stoichiometric compounds. In this work, neutron diffraction of Nd(28+x)/3AlxSi6-xO26 (0 ≤ x ≤ 1.5) single crystals identified the locations of oxygen interstitials, and allowed the deduction of a dual-path conduction mechanism that is a natural extension of the single-path sinusoidal channel trajectory arrived at through computation. This discovery provides the most thorough understanding of the O(2-) transport mechanism along the channels to date, clarifies the mode of interchannel motion, and presents a complete picture of O(2-) percolation through apatite. Previously reported crystallographic and conductivity measurements are re-examined in the light of these new findings. PMID:27015162

  1. Thermal history of Michigan Basin and Southern Canadian Shield from apatite fission track analysis

    NASA Astrophysics Data System (ADS)

    Crowley, Kevin D.

    1991-01-01

    Apatite fission track ages and confined-length distributions were collected from 38 basement outcrop and 5 basement drillcore samples in order to reconstruct the Phanerozoic thermal history of the Michigan Basin and southern Canadian Shield. The apatite data indicate two periods of thermal activity in the region: Triassic heating/cooling that affected the basin and adjacent shield and Cretaceous or post-Cretaceous heating/cooling that primarily affected the basin. The magnitude, timing, and cause of Cretaceous thermal activity cannot be identified with the present data. Model calculations suggest that some of the shield samples and probably all of the basin samples were heated to temperatures of at least 90°C just prior to relatively rapid cooling in the Triassic. Available stratigraphic and geochemical constraints suggest that these elevated temperatures were the result of burial by an additional 2-5 km of late Paleozoic (probably Pennsylvanian and Permian) sediments. It is likely that the basin was buried during the Alleghenian Orogeny as observed for the adjacent Appalachian Basin.

  2. Thermal history of Michigan Basin and southern Canadian Shield from apatite fission track analysis

    SciTech Connect

    Crowley, K.D. )

    1991-01-10

    Apatite fission track ages and confined-length distributions were collected from 38 basement outcrop and 5 basement drillcore samples in order to reconstruct the Phanerozoic thermal history of the Michigan Basin and southern Canadian Shield. The apatite data indicate two periods of thermal activity in the region: Triassic heating/cooling that affected the basin and adjacent shield and Cretaceous or post-Cretaceous heating/cooling that primarily affected the basin. The magnitude, timing, and cause of Cretaceous thermal activity cannot be identified with the present data. Model calculations suggest that some of the shield samples and probably all of the basin samples were heated to temperatures of at least 90C just prior to relatively rapid cooling in the Triassic. Available stratigraphic and geochemical constraints suggest that these elevated temperatures were the result of burial by an additional 2-5 km of late Paleozoic (probably Pennsylvanian and Permian) sediments. It is likely that the basin was buried during the Alleghenian Orogeny as observed for the adjacent Appalachian Basin.

  3. Surface treatment, corrosion behavior, and apatite-forming ability of Ti-45Nb implant alloy.

    PubMed

    Gostin, Petre F; Helth, Arne; Voss, Andrea; Sueptitz, Ralph; Calin, Mariana; Eckert, Jürgen; Gebert, Annett

    2013-02-01

    The low modulus β-type Ti-45Nb alloy is a promising new implant alloy due to its excellent mechanical biocompatibility and composition of non-toxic elements. The effect of surface treatments on the evolution of controlled topography and roughness was investigated by means of scanning electron microscopy and optical profilometry. Severe mechanical treatments, for example sand-blasting, or etching treatments in strongly oxidizing acidic solutions, like HF:HNO(3) (4:1) or H(2)SO(4):H(2)O(2) (1:1) piranha solution were found to be very effective. In particular, the latter generates a nanopatterned surface topography which is expected to be promising for the stimulation of bone tissue growth. Compared to Ti and Ti-6Al-4V, the β-type Ti-45Nb alloy requires significantly longer etching durations due to the high chemical stability of Nb. Severe surface treatments alter the passive film properties, but do not deteriorate the outstanding corrosion resistance of the Ti-45Nb alloy in synthetic body fluid environments. The Ti-45Nb appears to have a lower apatite-formation ability compared to Ti. Etching with H(2)SO(4):H(2)O(2) (1:1) piranha solution inhibits apatite formation on Ti, but not on Ti-45Nb. PMID:23166048

  4. Microwave assisted apatite coating deposition on Ti6Al4V implants.

    PubMed

    Zhou, Huan; Nabiyouni, Maryam; Bhaduri, Sarit B

    2013-10-01

    In this work we report a novel microwave assisted technology to deposit a uniform, ultra-thin apatite coating without any cracks on titanium implants in minutes. This method comprises of conventional biomimetic coating in synergism with microwave irradiation to result in alkaline earth phosphate nucleation. The microwave assisted coating process mainly follows the initial stages of biomimetic coating until the step of the Ca-P nuclei formation. After that, due to microwave irradiation more Ca-P nuclei are formed to cover the whole surface of the implant instead of the growth of deposited Ca-P nuclei to Ca-P globules and coatings. It is interesting to note the doping of Mg(2+) to Ca-P apatite coating can significantly change the properties and performances of as-deposited coatings. The hydrophilicity, physical properties, bioactivity, cell adhesion, and growth capability of as-deposited microwave assisted coatings were investigated. The study shows that this coating technology has great potential in biomedical applications. Additionally, since biomimetic coating can be applied to series of implant materials such as polymer, metals and glass, it is expected this microwave assisted coating technology can also be applied to these materials if they can remains stable at 100 °C, the boiling point of water. PMID:23910363

  5. Sorption behavior of Zn(II) ions on synthetic apatitic calcium phosphates

    NASA Astrophysics Data System (ADS)

    Sebei, Haroun; Pham Minh, Doan; Nzihou, Ange; Sharrock, Patrick

    2015-12-01

    The synthesis, characterization and the reactivity of apatitic calcium phosphates (Ca-HA, chemical formula Ca10(PO4)6(OH)2) is reported. Calcium carbonate (CaCO3) and potassium dihydrogen orthophosphate (KH2PO4) were selected as economical starting materials for the synthesis of Ca-HA under atmospheric conditions. Monocalcium phosphate monohydrate (MCPM), dicalcium phosphate dihydrate (DCPD), and octacalcium phosphate pentahydrate (OCP) were identified as the main intermediates of the synthesis reaction. The product obtained after 48 h of reaction contains mainly low-crystalline Ca-HA and small amounts of other calcium phosphates such as octacalcium phosphate (OCP), B-type carbonate apatite (CAP), as well as unreacted calcium carbonate. This Ca-HA was found to be active for the removal of Zn2+ from an aqueous solution. Its sorption capacity reached up to 120 mg of Zn2+ per g of Ca-HA powder after 24 h of reaction. The monitoring of soluble Zn, Ca and P during the sorption experiment allowed characterizing the mechanism of Zn uptake. Dissolution-precipitation, ionic exchange and surface complexation are the three main mechanisms involved in the sorption processes. The contribution of these mechanisms is discussed in detail.

  6. Sorption of selenium anionic species on apatites and iron oxides from aqueous solutions.

    PubMed

    Duc, Myriam; Lefevre, Gregory; Fedoroff, Michel; Jeanjean, Janine; Rouchaud, J C; Monteil-Rivera, Fanny; Dumonceau, Jacques; Milonjic, Slobodan

    2003-01-01

    The sorption of selenite and selenate ions from aqueous solutions was investigated on hydroxyapatite, fluorapatite, goethite and hematite, in order to simulate the behavior of radioactive selenium in natural or artificial sorbing media. Correlation studies with acido-basic properties and solubility of the solids were also performed. The sorption is pH dependant, but these solids are very efficient for retaining selenite at pH values generally encountered in natural waters, with however higher K(d) values for oxides than apatites. Selenate ions are much less sorbed than selenite. Several methods such as electron microscopy and spectroscopic techniques were used to identify the sorption mechanisms. In the case of hydroxyapatite, sorption proceeds by substitution of phosphate groups in the lattice of the apatite crystal in the superficial layers of the solid. In the case of goethite and hematite, sorption can be interpreted and modeled by a surface complexation process, but there is a discrepancy between sorption site densities for selenite and for protons.

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

    NASA Astrophysics Data System (ADS)

    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. Histological Comparison in Rats between Carbonate Apatite Fabricated from Gypsum and Sintered Hydroxyapatite on Bone Remodeling.

    PubMed

    Ayukawa, Yasunori; Suzuki, Yumiko; Tsuru, Kanji; Koyano, Kiyoshi; Ishikawa, Kunio

    2015-01-01

    Carbonate apatite (CO3Ap), the form of apatite found in bone, has recently attracted attention. The purpose of the present study was to histologically evaluate the tissue/cellular response toward the low-crystalline CO3Ap fabricated using a dissolution-precipitation reaction with set gypsum as a precursor. When set gypsum was immersed in a 100°C 1 mol/L Na3PO4 aqueous solution for 24 h, the set gypsum transformed into CO3Ap. Both CO3Ap and sintered hydroxyapatite (s-HAp), which was used as a control, were implanted into surgically created tibial bone defects of rats for histological evaluation. Two and 4 weeks after the implantation, histological sections were created and observed using light microscopy. The CO3Ap granules revealed both direct apposition of the bone matrix by osteoblasts and osteoclastic resorption. In contrast, the s-HAp granules maintained their contour even after 4 weeks following implantation which implied that there was a lack of replacement into the bone. The s-HAp granules were sometimes encapsulated with fibrous tissue, and macrophage polykaryon was occasionally observed directly apposed to the implanted granules. From the viewpoint of bone remodeling, the CO3Ap granules mimicked the bone matrix, suggesting that CO3Ap may be an appropriate bone substitute. PMID:26504813

  9. Bonelike apatite formation on niobium metal treated in aqueous NaOH.

    PubMed

    Godley, Reut; Starosvetsky, David; Gotman, Irena

    2004-10-01

    The essential condition for a biomaterial to bond to the living bone is the formation of a biologically active bonelike apatite on its surface. In the present work, it has been demonstrated that chemical treatment can be used to create a calcium phosphate (CaP) surface layer, which might provide the alkali treated Nb metal with bone-bonding capability. Soaking Nb samples in 0.5 M NaOH, at 25 degrees C for 24 h produced a nano-porous approximately 40 nm thick amorphous sodium niobate hydrogel layer on their surface. Immersion in a simulated body fluid (SBF) lead to the deposition of an amorphous calcium phosphate layer on the alkali treated Nb. The formation of calcium phosphate is assumed to be a result of the local pH increase caused by the cathodic reaction of oxygen reduction on the finely porous surface of the alkali-treated metal. The local rise in pH increased the ionic activity product of hydroxyapatite and lead to the precipitation of CaP from SBF that was already supersaturated with respect to the apatite. The formation of a similar CaP layer upon implantation of alkali treated Nb into the human body should promote the bonding of the implant to the surrounding bone. This bone bonding capability could make Nb metal an attractive material for hard tissue replacements. PMID:15516867

  10. Ultrastructural study of apatite crystal dissolution in human dentine and bone.

    PubMed

    Voegel, J C; Frank, R M

    1977-09-01

    The width and thickness of normal apatite monocrystals were determined in human dentine and alveolar bone on non-decalcified thin sections made perpendicular to the c axis. A mean width (L) of 364.50 A +/- 14.50 A and 562.10 A +/- 19 A was respectively found for dentine and bone monocrystals, whereas their mean thickness (E) was respectively 103.30 A +/- 2.70 A and 79.10 A +/- 3.10 A. The study of the ratio L.E.-1 for dentine and bone monocrystals showed a plate-like configuration which was more accentuated in bone crystals. Apatite crystal dissolution was studied during the carious process in dentine and bone resorption during advanced periodontal lesions. It could be shown that, in both conditions, one or several central core lesions developed along the c axis of the crystals. These central core lesions, extending laterally along (100) planes, progressively fused together, leading to the splitting up of the monocrystals into two thin plates by a complete destruction of the central part of the monocrystal.

  11. Osteoblastic cell response to thin film of poorly crystalline calcium phosphate apatite formed at low temperatures.

    PubMed

    Hong, Ji-Yeon; Kim, Yoon Jung; Lee, Hee-Woo; Lee, Woo-Kul; Ko, Jea Seung; Kim, Hyun-Man

    2003-08-01

    The response of osteoblastic cells to a thin film of poorly crystalline calcium phosphate apatite crystals (PCA) was examined in vitro. The PCA thin film was prepared on polystyrene culture dishes using highly metastable calcium phosphate ion solution at low temperatures. The PCA thin film was formed through fusion and transformation of granular calcium phosphate particles, which had initially formed on the surface, into a film of calcium phosphate apatite crystal. The PCA thin film was used for cell culture without additional surface treatment. The osteoblastic cell behaviors including adhesion, proliferation, expression of the marker genes, and calcified matrix formation were examined on the PCA thin film using primary osteoblasts or MC3T3-E1 cells. The cells were well attached and had spread in a slender shape over the PCA thin film. The extent of cell proliferation on the PCA thin film is as much as on the plain dishes. In addition, a much larger number of calcified nodules had formed on the PCA thin film than on the plain dish. The expression of the marker genes such as alkaline phosphatase, osteocalcin, osteopontin, osteonectin was apparent. These results demonstrate that the osteoblasts exhibit a full spectrum of cellular activity including the adequate differentiation on the PCA thin film. Therefore, a PCA thin film can be used as a coating material for biomaterials where the surface is not adequate for inducing the full activity of bone cells.

  12. A first report of hydroxylated apatite as structural biomineral in Loasaceae – plants’ teeth against herbivores

    PubMed Central

    Ensikat, Hans-Jürgen; Geisler, Thorsten; Weigend, Maximilian

    2016-01-01

    Biomineralization provides living organisms with various materials for the formation of resilient structures. Calcium phosphate is the main component of teeth and bones in vertebrates, whereas especially silica serves for the protection against herbivores on many plant surfaces. Functional calcium phosphate structures are well-known from the animal kingdom, but had not so far been reported from higher plants. Here, we document the occurrence of calcium phosphate biomineralization in the South-American plant group Loasaceae (rock nettle family), which have stinging trichomes similar to those of the well-known stinging nettles (Urtica). Stinging hairs and the smaller, glochidiate trichomes contained nanocrystalline hydroxylated apatite, especially in their distal portions, replacing the silica found in analogous structures of other flowering plants. This could be demonstrated by chemical, spectroscopic, and diffraction analyses. Some species of Loasaceae contained both calcium phosphate and silica in addition to calcium carbonate. The intriguing discovery of structural hydroxylated apatite in plants invites further studies, e.g., on its systematic distribution across the family, the genetic and cellular control of plant biomineralization, the properties and ultrastructure of calcium phosphate. It may prove the starting point for the development of biomimetic calcium phosphate composites based on a cellulose matrix. PMID:27194462

  13. Apatite intergrowths in clinopyroxene megacrysts from the Ostrzyca Proboszczowicka (SW Poland) basanite

    NASA Astrophysics Data System (ADS)

    Lipa, Danuta; Puziewicz, Jacek; Ntaflos, Theodoros; Matusiak-Małek, Magdalena

    2015-04-01

    The Cenozoic basanite from the Ostrzyca Proboszczowicka in Lower Silesia (SW Poland) belongs to numerous lavas occurring in the NE part of the Central European Volcanic Province. Basanite contains clinopyroxene megacrysts up to 3 cm in size. The clinopyroxene has the composition of aluminian-sodian diopside (mg# 0.61-0.70, 0.08-0.12 atoms Na pfu and 0.88-0.93 atoms Ca pfu). Cr is absent. The REE contents are above the primitive mantle reaching up to 18 x PM at Nd. Primitive-mantle normalized REE patterns show enrichment in LREE relative to HREE (LaN/LuN=3.81-5.01). The REE patterns of all the megacrysts show deflection in La-Nd. The trace element patterns are characterized by positive Zr, Hf and in some cases also Ta anomalies, and negative U, La, Sr, Ti and Pb ones. In some samples strong depletion (down to 0.01 x PM) in Rb and Ba is observed.The Ostrzyca megacrysts formed cumulate, which crystallized from magma similar to the host basanite, but more fractionated and enriched in REE, particularly in LREE (Lipa et al., 2014). This happened at mid-crustal depths (10-15 km) and the new pulse of basanitic magma entrained the crystals forming the non-solidified cumulate and brought them to the surface (Lipa et al., 2014). Clinopyroxene megacrysts contain large, transparent, euhedral apatite crystals up to 7 mm. The major element composition indicates the fluor-apatite with F content ranging from 0.87 to 1.93 wt.%. Chlorine content is strongly variable between grains (0.05-1.75 wt.%). Apatite is strongly enriched in LREE relative to HREE (LaN/LuN=60.39-62.23, about 1000 x PM for LREE and about 10 x PM for HREE). The REE patterns are nearly linear, with slight positive Nd and Gd anomalies. The trace element patterns are characterized by very strong negative anomalies of HFSE (Nb, Ta, Zr, Hf, Ti) and Pb, and weaker negative Sr anomaly. Concentration of Yb and Lu is on the level 10 x PM, whereas Rb, Hf and Ti are depleted relative to PM. Apatite preceded clinopyroxene

  14. Nanocrystalline carbonate-apatites: role of Ca/P ratio on the upload and release of anticancer platinum bisphosphonates

    NASA Astrophysics Data System (ADS)

    Iafisco, Michele; Palazzo, Barbara; Martra, Gianmario; Margiotta, Nicola; Piccinonna, Sara; Natile, Giovanni; Gandin, Valentina; Marzano, Cristina; Roveri, Norberto

    2011-12-01

    In the present study two nanocrystalline apatites have been investigated as bone-specific drug delivery devices to be used for treatment of bone tumors either by local implantation or by injection. In order to assess how the Ca/P ratio can influence the adsorption and release of anticancer platinum-bisphosphonate complexes, two kinds of apatite nanocrystals having different Ca/P ratios but similar morphologies, degree of crystallinity, and surface areas have been synthesized and characterized. The two platinum-bisphosphonate complexes considered were the bis-{ethylenediamineplatinum(ii)}-2-amino-1-hydroxyethane-1,1-diyl-bisphosphonate and the bis-{ethylenediamineplatinum(ii)}medronate. The Ca/P ratio plays an important role in the adsorption as well as in the release of the two drugs. In fact, the apatite with a higher Ca/P ratio showed greater affinity for both platinum complexes. Also the chemical structure of the two Pt complexes appreciably affects their affinity towards as well as their release from the two kinds of apatites. In particular, the platinum complex whose bisphosphonate contains a free aminic group showed greater upload and smaller release. The cytotoxicity of the Pt complexes released from the apatite was tested against human cervical, colon, and lung cancer cells as well as against osteosarcoma cells. In agreement with previous work, the Pt complexes released were found to be more cytotoxic than the unmodified complexes.In the present study two nanocrystalline apatites have been investigated as bone-specific drug delivery devices to be used for treatment of bone tumors either by local implantation or by injection. In order to assess how the Ca/P ratio can influence the adsorption and release of anticancer platinum-bisphosphonate complexes, two kinds of apatite nanocrystals having different Ca/P ratios but similar morphologies, degree of crystallinity, and surface areas have been synthesized and characterized. The two platinum

  15. Experimental Determination of Hydrogen Partitioning in an Apatite-Haplobasalt Andesite Melt System at 1200°C and 1 GPa

    NASA Astrophysics Data System (ADS)

    Huh, M. C.; Boyce, J.; Manning, C. E.; Medard, E.

    2011-12-01

    Igneous apatite crystals contain a record of the evolving concentrations of magmatic volatile elements such as F, H, and Cl during crystallization and degassing. In order to develop apatite as a quantitative barometer of magmatic volatile species, improved understanding of apatite-melt volatile equilibria is needed. We conducted apatite crystallization experiments using a piston cylinder apparatus at 1,200°C and 1 GPa. Apatite crystals were grown from an Fe- and Cl-free, haplobasaltic-andesite melt of constant composition. Experiments were quenched to below 700°C in 15 seconds, producing homogeneous glass plus apatite crystals ranging from 5 to 30 microns in diameter. Apatite and coexisting glass were analyzed using the Cameca ims 6f SIMS, with an O- beam and positive secondary ions, following the methods of Boyce and Hervig (2008, 2009), but using the inversion-based calibration routines of Boyce and Eiler (this meeting). These measurements provide the first direct constraint on the partitioning of hydrogen between apatite and melt. For the exchange reaction F-(melt) + OHapatite = OH-(melt) + Fapatite, the Keq was calculated from the measured data to be ~25, consistent with the results of Mathez and Webster (2004) and Webster et al. (2008), despite our experiments being nominally Cl- and Fe-free. Significant non-Henrian behavior is observed for hydrogen, but trace F behaves effectively Henrian at low concentrations, again consistent with previous work. These preliminary results reinforce the assertion that simple Henry's or Raoult's Law models of volatile partitioning between apatite and melt are rarely - if ever - appropriate, and that both F and H concentrations must be considered in order to use hydrogen concentrations in apatite to determine concentrations of hydrogen in the coexisting melt.

  16. SUPERFUND TREATABILITY CLEARINGHOUSE: FULL SCALE ROTARY KILN INCINERATOR FIELD TRIAL: PHASE I, VERIFICATION TRIAL BURN ON DIOXIN/HERBICIDE ORANGE CONTAMINATED SOIL

    EPA Science Inventory

    This treatability study reports on the results of one of a series of field trials using various remedial action technologies that may be capable of restoring Herbicide Orange (HO)XDioxin contaminated sites. A full-scale field trial using a rotary kiln incinerator capable of pro...

  17. Oxygen isotope fractionation between apatite-bound carbonate and water determined from controlled experiments with synthetic apatites precipitated at 10-37 °C

    NASA Astrophysics Data System (ADS)

    Lécuyer, Christophe; Balter, Vincent; Martineau, François; Fourel, François; Bernard, Aurélien; Amiot, Romain; Gardien, Véronique; Otero, Olga; Legendre, Serge; Panczer, Gérard; Simon, Laurent; Martini, Rossana

    2010-04-01

    The oxygen isotope fractionation between the structural carbonate of inorganically precipitated hydroxyapatite (HAP) and water was determined in the range 10-37 °C. Values of 1000 ln α( CO32--HO) are linearly correlated with inverse temperature (K) according to the following equation: 1000 ln α( CO32--HO) = 25.19 (±0.53)· T-1 - 56.47 (±1.81) ( R2 = 0.998). This fractionation equation has a slightly steeper slope than those already established between calcite and water ( O'Neil et al., 1969; Kim and O'Neil, 1997) even though measured fractionations are of comparable amplitude in the temperature range of these experimental studies. It is consequently observed that the oxygen isotope fractionation between apatite carbonate and phosphate increases from about 7.5‰ up to 9.1‰ with decreasing temperature from 37 °C to 10 °C. A compilation of δ 18O values of both phosphate and carbonate from modern mammal teeth and bones confirms that both variables are linearly correlated, despite a significant scattering up to 3.5‰, with a slope close to 1 and an intercept corresponding to a 1000 ln α( CO32--PO43-) value of 8.1‰. This apparent fractionation factor is slightly higher or close to the fractionation factor expected to be in the range 7-8‰ at the body temperature of mammals.

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

    NASA Astrophysics Data System (ADS)

    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

  19. Apatite-coated Silk Fibroin Scaffolds to Healing Mandibular Border Defects in Canines

    PubMed Central

    Zhao, Jun; Zhang, Zhiyuan; Wang, Shaoyi; Sun, Xiaojuan; Zhang, Xiuli; Chen, Jake; Kaplan, David L.; Jiang, Xinquan

    2010-01-01

    Tissue engineering has become a new approach for repairing bony defects. Highly porous osteoconductive scaffolds perform the important role for the success of bone regeneration. By biomimetic strategy, apatite-coated porous biomaterial based on silk fibroin scaffolds (SS) might provide an enhanced osteogenic environment for bone-related outcomes. To assess the effects of apatite-coated silk fibroin (mSS) biomaterials for bone healing as a tissue engineered bony scaffold, we explored a tissue engineered bony graft using mSS seeded with osteogenically induced autologous bone marrow stromal cells (bMSCs) to repair inferior mandibular border defects in a canine model. The results were compared with those treated with bMSCs/SS constructs, mSS alone, SS alone, autologous mandibular grafts and untreated blank defects. According to radiographic and histological examination, new bone formation was observed from 4 weeks post-operation, and the defect site was completely repaired after 12 months for the bMSCs/mSS group. In the bMSCs/SS group, new bone formation was observed with more residual silk scaffold remaining at the center of the defect compared with the bMSCs/mSS group. The engineered bone with bMSCs/mSS achieved satisfactory bone mineral densities (BMD) at 12 months post-operation close to those of normal mandible (p>0.05). The quantities of newly formed bone area for the bMSCs/mSS group was higher than the bMSCs/SS group (p<0.01), but no significant differences were found when compared with the autograft group (p>0.05). In contrast, bony defects remained in the center with undegraded silk fibroin scaffold and fibrous connective tissue, and new bone only formed at the periphery in the groups treated with mSS or SS alone. The results suggested apatite-coated silk fibroin scaffolds combined with bMSCs could be successfully used to repair mandibular critical size border defects and the premineralization of these porous silk fibroin protein scaffolds provided an

  20. Volatile budget of Tenerife phonolites inferred from combined haüyne-apatite mineral records

    NASA Astrophysics Data System (ADS)

    Cooper, Lauren B.; Bachmann, Olivier; Huber, Christian

    2015-04-01

    Intermediate to silicic volcanic eruptions often emit more S than predicted by petrological models -- this is called the "excess S problem." While most common minerals in these magmas are poor in volatile elements, the occurrence of large phenocrysts of S-rich haüyne (up to ~13 wt% SO3) in phonolites holds much promise for better constraining volcanic volatile budgets in differentiated alkaline magmatic systems. We have examined textural zonation patterns in haüyne separates from Tenerife (Spain), using mineral oil to enhance grain transparency. Included phases were characterized by energy dispersive spectroscopy, X-ray maps, and Raman spectroscopy. Slow growth of haüyne, inferred from zones with few inclusions, likely represents cooling-induced crystallization from S-rich melt during storage in the upper crust. By contrast, rapid growth of phenocrystic haüyne, generating "wispy" zones containing Fe-rich haüyne laths and zones rich in melt inclusions, fluid inclusions, and Fe-sulfide inclusions, may be associated with magma recharge and/or upward percolation of a low-density fluid phase (i.e., "gas sparging"). Both processes could bring new pulses of S from deep within the magmatic system. Zones containing thousands of fluid inclusions provide direct physical evidence that the melt was fluid-saturated during periods of rapid haüyne growth. Transfer of S-rich fluid should occur in all volatile-rich magmatic systems, including dacitic-rhyolitic arc systems with large S excesses, but is difficult to document in such magmas devoid of a large S-rich mineral phase like haüyne. Apatite, a mineral present in all volcanic rocks, may also contain information about S. We have observed intricate chemical zonation in backscattered electron images of apatite microphenocrysts from the same Tenerife samples. Variations in volatile and trace element concentrations between successive zones (measured via wavelength dispersive spectroscopy and laser ablation-inductively coupled

  1. Investigation of the stability of Co-doped apatite ionic conductors in NH{sub 3}

    SciTech Connect

    Headspith, D.A.; Orera, A.; Young, N.A.; Francesconi, M.G.

    2010-12-15

    Hydrogen powered solid oxide fuel cells (SOFCs) are of enormous interest as devices for the efficient and clean production of electrical energy. However, a number of problems linked to hydrogen production, storage and transportation are slowing down the larger scale use of SOFCs. Identifying alternative fuel sources to act as intermediate during the transition to the full use of hydrogen is, therefore, of importance. One excellent alternative is ammonia, which is produced on a large scale, is relatively cheap and has the infrastructure for storage and transportation already in place. However, considering that SOFCs operate at temperatures higher than 500 {sup o}C, a potential problem is the interaction of gaseous ammonia with the materials in the cathode, anode and solid electrolyte. In this paper, we extend earlier work on high temperature reactions of apatite electrolytes with NH{sub 3} to the transition metal (Co) doped systems, La{sub 9.67}Si{sub 5}CoO{sub 26} and La{sub 10}(Si/Ge){sub 5}CoO{sub 26.5}. A combination of PXRD, TGA and XAFS spectroscopy data showed a better structural stability for the silicate systems. Apatite silicates and germanates not containing transition metals tend to substitute nitride anions for their interstitial oxide anions, when reacted with NH{sub 3} at high temperature and, consequentially, lower the interstitial oxide content. In La{sub 9.67}Si{sub 5}CoO{sub 26} and La{sub 10}(Si/Ge){sub 5}CoO{sub 26.5} reduction of Co occurs as a competing process, favouring lower levels of nitride-oxide substitution. -- Graphical Abstract: In reactions between the apatites La{sub 9.67}Si{sub 5}CoO{sub 26} and La{sub 10}(Si/Ge){sub 5}CoO{sub 26.5} and NH{sub 3} (g) at temperatures T>500 {sup o}C, the partial substitution of the Si and Ge by Co seems to discourage O{sup 2-}/N{sup 3-} substitution in favour of the reduction of the metal. Display Omitted

  2. S-rich apatite-hosted glass inclusions in xenoliths from La Palma: constraints on the volatile partitioning in evolved alkaline magmas

    NASA Astrophysics Data System (ADS)

    Parat, Fleurice; Holtz, François; Klügel, Andreas

    2011-09-01

    The composition of S-rich apatite, of volatile-rich glass inclusions in apatite, and of interstitial glasses in alkaline xenoliths from the 1949 basanite eruption in La Palma has been investigated to constrain the partitioning of volatiles between apatite and alkali-rich melts. The xenoliths are interpreted as cumulates from alkaline La Palma magmas. Apatite contains up to 0.89 wt% SO3 (3560 ppm S), 0.31 wt% Cl, and 0.66 wt% Ce2O3. Sulfur is incorporated in apatite via several independent exchange reactions involving (P5+, Ca2+) vs. (S6+, Si4+, Na+, and Ce3+). The concentration of halogens in phonolitic to trachytic glasses ranges from 0.15 to 0.44 wt% for Cl and from <0.07 to 0.65 wt% for F. The sulfur concentration in the glasses ranges from 0.06 to 0.23 wt% SO3 (sulfate-saturated systems). The chlorine partition coefficients (D{Cl/apatite/glass}) range from 0.4 to 1.3 (average D{Cl/apatite/glass} = 0.8), in good agreement with the results of experimental data in mafic and rhyolitic system with low Cl concentrations. With increasing F in glass inclusions D{F/apatite/glass} decreases from 35 to 3. However, most of our data display a high partition coefficient (~30) close to D{F/apatite/glass} determined experimentally in felsic rock. D{S/apatite/glass} decreases from 9.1 to 2.9 with increasing SO3 in glass inclusions. The combination of natural and experimental data reveals that the S partition coefficient tends toward a value of 2 for high S content in the glass (>0.2 wt% SO3). D{S/apatite/glass} is only slightly dependent on the melt composition and can be expressed as: SO3 apatite (wt%) = 0.157 * ln SO3 glass (wt%) + 0.9834. The phonolitic compositions of glass inclusions in amphibole and haüyne are very similar to evolved melts erupted on La Palma. The lower sulfur content and the higher Cl content in the phonolitic melt compared to basaltic magmas erupted in La Palma suggest that during magma evolution the crystallization of haüyne and pyrrhotite probably

  3. Removal of fluoride from aqueous solution by adsorption on Apatitic tricalcium phosphate using Box-Behnken design and desirability function

    NASA Astrophysics Data System (ADS)

    Mourabet, M.; El Rhilassi, A.; El Boujaady, H.; Bennani-Ziatni, M.; El Hamri, R.; Taitai, A.

    2012-03-01

    The adsorption method was used for fluoride removal from aqueous solution by Apatitic tricalcium phosphate. In this study, response surface methodology was employed for the removal of fluoride. Experiments were carried out as per Box-Behnken surface statistical design with four input parameters namely adsorbent dose (0.1-0.3 g), initial concentration (30-60 mg L-1), temperature (20-40 °C) and pH (4-11). Contact time (90 min) was taken as a fixed input parameter. Regression analysis showed good fit of the experimental data to the second-order polynomial model with coefficient of determination (R2) value of 0.966 and Fisher F-value of 10.28. Applying the method of the desirability function, optimization of adsorbent dose (29 g), initial concentration (60 mg L-1), T (40 °C) and pH (4) gave a maximum of 82.34% fluoride removal white desirability of 0.916 by Apatitic tricalcium phosphate. Dynamic adsorption data were applied to pseudo-first-order and pseudo-second-order rate equations. Pseudo-second-order kinetic model well expressed fluoride adsorption onto Apatitic tricalcium phosphate. According to the correlation coefficients, the adsorption of fluoride on the Apatitic tricalcium phosphate was correlated well with the Langmuir and Freundlich models.

  4. Characterization of mesostasis regions in lunar basalts: Understanding late-stage melt evolution and its influence on apatite formation

    NASA Astrophysics Data System (ADS)

    Potts, Nicola J.; TartèSe, Romain; Anand, Mahesh; Westrenen, Wim; Griffiths, Alexandra A.; Barrett, Thomas J.; Franchi, Ian A.

    2016-09-01

    Recent studies geared toward understanding the volatile abundances of the lunar interior have focused on the volatile-bearing accessory mineral apatite. Translating measurements of volatile abundances in lunar apatite into the volatile inventory of the silicate melts from which they crystallized, and ultimately of the mantle source regions of lunar magmas, however, has proved more difficult than initially thought. In this contribution, we report a detailed characterization of mesostasis regions in four Apollo mare basalts (10044, 12064, 15058, and 70035) in order to ascertain the compositions of the melts from which apatite crystallized. The texture, modal mineralogy, and reconstructed bulk composition of these mesostasis regions vary greatly within and between samples. There is no clear relationship between bulk-rock basaltic composition and that of bulk-mesostasis regions, indicating that bulk-rock composition may have little influence on mesostasis compositions. The development of individual melt pockets, combined with the occurrence of silicate liquid immiscibility, exerts greater control on the composition and texture of mesostasis regions. In general, the reconstructed late-stage lunar melts have roughly andesitic to dacitic compositions with low alkali contents, displaying much higher SiO2 abundances than the bulk compositions of their host magmatic rocks. Relevant partition coefficients for apatite-melt volatile partitioning under lunar conditions should, therefore, be derived from experiments conducted using intermediate compositions instead of compositions representing mare basalts.

  5. Framework 'interstitial' oxygen in La(10)(GeO(4))(5-)(GeO(5))O(2) apatite electrolyte.

    PubMed

    Pramana, Stevin S; Klooster, Wim T; White, T J

    2007-08-01

    Oxygen conduction at low temperatures in apatites make these materials potentially useful as electrolytes in solid-oxide fuel cells, but our understanding of the defect structures enabling ion migration is incomplete. While conduction along [001] channels is dominant, considerable inter-tunnel mobility has been recognized. Using neutron powder diffraction of stoichiometric 'La(10)(GeO(4))(6)O(3)', it has been shown that this compound is more correctly described as an La(10)(GeO(4))(5-)(GeO(5))O(2) apatite, in which high concentrations of interstitial oxygen reside within the channel walls. It is suggested that these framework interstitial O atoms provide a reservoir of ions that can migrate into the conducting channels of apatite, via a mechanism of inter-tunnel oxygen diffusion that transiently converts GeO(4) tetrahedra to GeO(5) distorted trigonal bipyramids. This structural modification is consistent with known crystal chemistry and may occur generally in oxide apatites.

  6. Effect of wollastonite ceramics and bioactive glass on the formation of a bonelike apatite layer on a cobalt base alloy.

    PubMed

    Cortés, D A; Medina, A; Escobedo, J C; Escobedo, S; López, M A

    2004-08-01

    A biomimetic method was used to promote a bioactive surface on a cobalt base alloy (ASTM F-75). The metallic substrates were alkali treated and some of the samples were subsequently heat treated. The treated samples were immersed in simulated body fluid (SBF) on granular particles of either bioactive glass or wollastonite. For comparative purposes, no bioactive system was used in some tests. Three different methods were used for the immersion of the samples in SBF: 1) 21 days in SBF, 2) 21 days in 1.5 SBF, and 3) 7 days in SBF followed by 14 days in 1.5 SBF (re-immersion method). A bonelike apatite layer was formed on all the samples placed on wollastonite and bioactive glass particles. The morphology of the apatite layer formed by using the re-immersion method and wollastonite closely resembled the existing bioactive systems. No apatite layer was observed on the samples treated without bioactive material and soaked for 21 days in SBF or 1.5 SBF, apart from the substrates treated by using the re-immersion method. The heat treatment delayed the apatite formation in all the cases studied.

  7. Comment on "Apatite: A new redox proxy for silicic magmas?" [Geochimica et Cosmochimica Acta 132 (2014) 101-119

    NASA Astrophysics Data System (ADS)

    Marks, Michael A. W.; Scharrer, Manuel; Ladenburger, Sara; Markl, Gregor

    2016-06-01

    Recently Miles et al. (2014) proposed that a negative correlation between oxygen fugacity (expressed as logfO2 and the Mn content of apatite from a range of intermediate to silicic igneous rocks could be used as an oxybarometer (Eq. (1)).

  8. Characterization of mesostasis regions in lunar basalts: Understanding late-stage melt evolution and its influence on apatite formation

    NASA Astrophysics Data System (ADS)

    Potts, Nicola J.; TartèSe, Romain; Anand, Mahesh; Westrenen, Wim; Griffiths, Alexandra A.; Barrett, Thomas J.; Franchi, Ian A.

    2016-07-01

    Recent studies geared toward understanding the volatile abundances of the lunar interior have focused on the volatile-bearing accessory mineral apatite. Translating measurements of volatile abundances in lunar apatite into the volatile inventory of the silicate melts from which they crystallized, and ultimately of the mantle source regions of lunar magmas, however, has proved more difficult than initially thought. In this contribution, we report a detailed characterization of mesostasis regions in four Apollo mare basalts (10044, 12064, 15058, and 70035) in order to ascertain the compositions of the melts from which apatite crystallized. The texture, modal mineralogy, and reconstructed bulk composition of these mesostasis regions vary greatly within and between samples. There is no clear relationship between bulk-rock basaltic composition and that of bulk-mesostasis regions, indicating that bulk-rock composition may have little influence on mesostasis compositions. The development of individual melt pockets, combined with the occurrence of silicate liquid immiscibility, exerts greater control on the composition and texture of mesostasis regions. In general, the reconstructed late-stage lunar melts have roughly andesitic to dacitic compositions with low alkali contents, displaying much higher SiO2 abundances than the bulk compositions of their host magmatic rocks. Relevant partition coefficients for apatite-melt volatile partitioning under lunar conditions should, therefore, be derived from experiments conducted using intermediate compositions instead of compositions representing mare basalts.

  9. 100-D Area In Situ Redox Treatability Test for Chromate-Contaminated Groundwater: FY 1998 Year-End Report

    SciTech Connect

    Williams, M.D.; Vermeul, V.R.; Szecsody, J.E.; Fruchter, J.S.; Cole, C.R.

    1999-04-15

    A treatability test was conducted for the In Situ Redox Manipulation (ISRM) technology at the US Department of Energy's Hanford, Washington 100D Area. The target contaminant was dissolved chromate [Cr(VI)] in groundwater. The ISRM technology involves creating a permeable subsurface treatment zone to reduce mobile chromate in groundwater to an insoluble form. The ISRM permeable treatment zone is created by reducing ferric iron [Fe(III)] to ferrous iron [Fe(II)] within the aquifer sediments. This is accomplished by injecting aqueous sodium dithionite into the aquifer and withdrawing the reaction products. The goal of the treatability test was to create a linear ISRM barrier by injecting sodium dithionite into five wells. Well installation and site characterization activities began in the spring of 1997. The first dithionite injection took place in September 1997. The results of this first injection were monitored through the spring of 1998; the remaining four dithionite injections were carried out in May through July of 1998. These five injections created a reduced zone in the Hanford unconfined aquifer 150 feet in length (perpendicular to groundwater flow) by 50 feet wide. The reduced zone extended over the thickness of the unconfined zone, which is approximately 15 feet. Analysis of recent groundwater sampling events shows that the concentrations of chromate [Cr(VI)] in groundwater in the reduced zone have been decreased from starting concentrations of approximately 900 ppb to below analytical detection limits (<7 ppb). Chromate concentrations are also declining in some downgradient monitoring wells. Laboratory analysis of iron in the soil indicates that the barrier should remain in place for approximately 20 to 25 years. These measurements will be confirmed by analysis of sediment cores in FY 1999.

  10. THE USE OF A TREATABILITY STUDY TO INVESTIGATE THE POTENTIAL FOR SELF HEATING & EXOTHERMIC REACTIONS IN DECONTAMINATION MATERIALS AT PFP

    SciTech Connect

    HOPKINS, A.M.

    2005-02-23

    Cerium Nitrate has been proposed for use in the decontamination of plutonium contaminated equipment at the Plutonium Finishing Plant (PFP) located on the Hanford Nuclear Reservation in eastern Washington. A Treatability Study was conducted to determine the validity of this decontamination technology in terms of meeting its performance goals and to understand the risks associated with the use of Cerium Nitrate under the conditions found at the PFP. Fluor Hanford is beginning the decommissioning of the PFP at the Hanford site. Aggressive chemicals are commonly used to remove transuranic contaminants from process equipment to allow disposal as low level waste. Chemicals being considered for decontamination of gloveboxes in PFP include cerium (IV) nitrate in a nitric acid solution, and proprietary commercial solutions that include acids, degreasers, and sequestering agents. Fluor's decontamination procedure involves application of the chemicals, followed by a wipe-down of the contaminated surfaces with rags. This process effectively transfers the decontamination liquids containing the transuranic materials to the rags, which can then be readily packaged for disposal as TRU waste. As part of a treatability study, Fluor Hanford and the Pacific Northwest National Laboratory (PNNL) have evaluated the potential for self-heating and exothermic reactions in the residual decontamination materials and the waste packages. Laboratory analyses and thermal-hydraulic modeling reveal a significant self-heating risk for cerium nitrate solutions when used with cotton rags. Exothermic reactions that release significant heat and off-gas have been discovered for cerium nitrate at higher temperatures. From these studies, limiting conditions have been defined to assure safe operations and waste packaging.

  11. Determination of Sr and Ba partition coefficients between apatite from fish ( Sparus aurata) and seawater: The influence of temperature

    NASA Astrophysics Data System (ADS)

    Balter, Vincent; Lécuyer, Christophe

    2010-06-01

    The Sr/Ca and Ba/Ca ratios in inorganic apatite are strongly dependent on the temperature of the aqueous medium during precipitation. If valid in biogenic apatite, these thermometers would offer the advantage of being more resistant to diagenesis than those calibrated on biogenic calcite and aragonite. We have reared seabreams ( Sparus aurata) in tanks with controlled conditions during experiments lasting for more than 2 years at 13, 17, 23 and 27 °C, in order to determine the variations in Sr and Ba partitioning relative to Ca ( DSr and DBa, respectively) between seawater and fish apatitic hard tissues (i.e. teeth and bones), as a function of temperature. The sensitivity of the Sr and Ba thermometers (i.e. ∂ DSr/∂ T and ∂ DBa/∂ T, respectively), are similar in bone ( ∂Db-wSr/∂ T = 0.0036 ± 0.0003 and ∂Db-wBa/∂ T = 0.0134 ± 0.0026, respectively) and enamel ( ∂De-wSr/∂ T = 0.0037 ± 0.0005 and ∂De-wBa/∂ T = 0.0107 ± 0.0026, respectively). The positive values of ∂ DSr/∂ T and ∂ DBa/∂ T in bone and enamel indicate that DSr and DBa increase with increasing temperature, a pattern opposite to that observed for inorganic apatite. This distinct thermodependent trace element partitioning between inorganic and organic apatite and water highlights the contradictory effects of the crystal-chemical and biological controls on the partitioning of Ca, Sr and Ba in vertebrate organisms. Taking into account the diet Sr/Ca and Ba/Ca values, it is shown that the bone Ba/Ca signature of fish can be explained by Ca-biopurification and inorganic apatite precipitation, whereas both of these processes fail to predict the bone Sr/Ca values. Therefore, the metabolism of Ca as a function of temperature still needs to be fully understood. However, the biogenic Sr thermometer is used to calculate an average seawater temperature of 30.6 °C using the Sr/Ca compositions of fossil shark teeth at the Cretaceous/Tertiary boundary, and a typical seawater Sr

  12. Polytopic Vector Analysis (PVA) modelling of whole-rock and apatite chemistry from the Karkonosze composite pluton (Poland, Czech Republic)

    NASA Astrophysics Data System (ADS)

    Lisowiec, Katarzyna; Słaby, Ewa; Förster, Hans-Jürgen

    2015-08-01

    This study presents a novel approach for analysing the magma evolution path in composite plutons, applying the so-termed Polytopic Vector Analysis (PVA) to whole-rock and apatite chemistry. As an example of a multiphase magmatic body the Karkonosze granitoid pluton was chosen, which formed by a combination of magma mixing and fractional crystallization of two distinct melts - granitic crust-derived and lamprophyric mantle-derived. The goal was to model end-member magma compositions recorded by apatite and to estimate to what extent these end-members interacted with each other. Although using single minerals as proxies to magma compositions is tricky, the studied apatite well reflects the compositional trends within the magma (e.g., decreasing LREE/Y ratios, varying halogen content, increasing Mn and Na concentrations). The results of PVA simulations for whole-rock geochemistry demonstrate a model similar to that constrained from previous studies. Apart from the main trend of mixing between a felsic (~ 80 wt.% SiO2) and a mafic (~ 53 wt.% SiO2) end-member (EM), an additional process has been recognized, representing most probably the continuous evolution of the mafic end-member, responsible for the compositional diversity of some rocks. One felsic (REE-poor, Mn-F-rich) and one mafic (Cl-Sr-Si-REE-rich) apatite end-members were recognized, whereas the third one represents most probably a fluid component (enriched in Si, Y, Ce and Nd), present at all magmatic stages, however, most prominent during the late stage. The widest range of EM proportions and the highest contribution of the mafic EM are displayed by apatites from the early stage. During the middle and late stages, the apatites present a narrow range of EM proportions, with almost all apatites bearing a felsic signature. This pattern reflects the progressive homogenization of the system. Although the PVA method applied to mineral chemistry poses some limitations, it may provide a more detailed image of the

  13. Apatite U-Pb thermochronolgy applied to complex geological settings - insights from geo/thermochronology and geochemistry

    NASA Astrophysics Data System (ADS)

    Paul, Andre; Spikings, Richard; Ulyanov, Alexey; Chew, David

    2016-04-01

    Application of high temperature (>350oC) thermochronology is limited to the U-Pb system of accessory minerals, such as apatite, under the assumption that radiogenic lead is lost to thermally activated volume diffusion into an infinite reservoir. Cochrane et al. (2015) have demonstrated a working example from the northern Andes of South America. Predictions from volume diffusion theory were compared with measured single grain U-Pb date correlated to shortest diffusion radius and in-situ profiles measured by LA-ICP-MS. Results from both techniques were found to be in agreement with predictions from thermally activated, volume diffusion. However, outliers from the ID-TIMS data suggested some complexity, as grains were found to be too young relative to their diffusion radius. Interaction of multiple processes can be responsible for the alteration of apatite U-Pb dates such as: (1) metamorphic (over)growth, (2) fluid aided alteration/recrystallization and (3) metamictization and fracturing of the grain. Further, predictions from volume diffusion rely on the input parameters: (a) diffusivity, (b) activation energy and (c) shortest diffusion radius. Diffusivity and activation energy are potentially influenced by the chemical composition and subsequent changes in crystal structure. Currently there is one value for diffusion parameter and activation energy established for (Durango) apatite (Cherniak et al., 1991). Correlation between diffusivity/activation energy and composition has not been established. We investigate if correlations exist between diffusivity/activation energy and composition by obtaining single grain apatite U-Pb date and chemical compostion and correlating these to their diffusion radius. We test the consistency of apatite closure temperature, by comparing the apatite U-Pb dates with lower temperature thermochronometers such as white mica and K-feldspar Ar/Ar and by petrographic observations. We test if chemical information can be a proxy to identify

  14. A nitrogen doped TiO2 layer on Ti metal for the enhanced formation of apatite.

    PubMed

    Hashimoto, Masami; Kashiwagi, Kazumi; Kitaoka, Satoshi

    2011-09-01

    Biomedical titanium metals subjected to gas under precisely regulated oxygen partial pressures (P(O2)) from 10(-18) to 10(5) Pa at 973 K for 1 h were soaked in a simulated body fluid (SBF), whose ion concentrations were nearly equal to those of human blood plasma, at 36.5°C for up to 7 days. The effect of oxygen partial pressures on apatite formation was assessed using X-ray diffraction (XRD), scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) measurements. After heating, the weight of the oxide layer (mainly TiO(2)) formed on the titanium metal was found to increase with increased oxygen partial pressure. Nitrogen (N)-doped TiO(2) (Interstitial N) was formed under a P(O2) of 10(-14) Pa. At lower P(O2) (10(-18) Pa), only a titanium nitride layer (TiN and Ti(2)N) was formed. After soaking in SBF, apatite was detected on heat-treated titanium metal samples. The most apatite was formed, based on the growth rate calculated from the apatite coverage ratio, on the titanium metal heated under a P(O2) of 10(-14) Pa, followed by the sample heated under a P(O2) of 10 and 10(4) Pa (in N(2)). The titanium metal heated under a P(O2) of 10(5) Pa (in O(2)) experienced far less apatite formation than the former three titanium samples. Similarly, very little weight change was observed for the titanium metal heated under a P(O2) of 10(-18) Pa (in N(2)). During the experimental observation period (5 days, 36.5°C, SBF), the following relationship held: The growth rate of apatite decreased in the order P(O2) of 10(-14) Pa > P(O2) of 10 Pa ≥ P(O2) of 10(4) Pa > P(O2) of 10(5) Pa > > P(O2) of 10(-18) Pa. These results suggest that N-doped TiO(2) (Interstitial N) strongly induces apatite formation but samples coated only with titanium nitride do not. Thus, controlling the formation of N-doped TiO(2) is expected to improve the bioactivity of biomedical titanium metal.

  15. Genesis of rare-metal pegmatites and alkaline apatite-fluorite rocks of Burpala massi, Northern Baikal folded zone

    NASA Astrophysics Data System (ADS)

    Sotnikova, Irina; Vladykin, Nikolai

    2015-04-01

    Burpalinsky rare metal alkaline massif in the Northern Baikal folded zone in southern margin of Siberian Platform, is a of intrusion central type, created 287 Ma covering area of about 250 km2. It is composed of nepheline syenites and pulaskites grading to quartz syenites in the contacts. Veines and dykes are represented by shonkinites, sodalite syenite, leucocratic granophyres, alkali granites and numerous rare metal alkaline syenite pegmatites and two dykes of carbonatites. All rocks except for granites are cut by a large apatite-fluorite dyke rocks with mica and magnetite, which in turn is cut by alaskite granites dyke. The massif has been studied by A.M. Portnov, A.A. Ganzeev et al. (1992) Burpalinsky massif is highly enriched with trace elements, which are concentrated in pegmatite dykes. About 70 rare-metal minerals we found in massif. Zr-silicates: zircon, eudialyte, lovenite, Ti-lovenite, velerite, burpalite, seidozerite, Ca- seidozerite, Rosenbuschite, vlasovite, katapleite, Ca-katapleite, elpidite. Ti- minerals:- sphene, astrophyllite, ramsaite, Mn-neptunite bafertisite, chevkinite, Mn-ilmenite, pirofanite, Sr-perrerit, landauite, rutile, anatase, brookite; TR- minerals - loparite, metaloparite, britolite, rinkolite, melanocerite, bastnesite, parisite, ankilite, monazite, fluocerite, TR-apatite; Nb- minerals - pyrochlore, loparite. Other rare minerals leucophanite, hambergite, pyrochlore, betafite, torite, thorianite, tayniolite, brewsterite, cryolite and others. We have proposed a new scheme massif: shonkinites - nepheline syenites - alkaline syenite - quartz syenites - veined rocks: mariupolites, rare-metal pegmatites, apatite, fluorite rock alyaskite and alkaline granites and carbonatites (Sotnikova, 2009). Apatite-fluorite rocks are found in the central part of massif. This is a large vein body of 2 km length and a 20 m width cutting prevailing pulaskites. Previously, these rocks were regarded as hydrothermal low-temperature phase. New geological and

  16. Fabrication and Intracellular Delivery of Doxorubicin/Carbonate Apatite Nanocomposites: Effect on Growth Retardation of Established Colon Tumor

    PubMed Central

    Chowdhury, Ezharul Hoque; Wu, Xin; Hirose, Hajime; Haque, Amranul; Doki, Yuichiro; Mori, Masaki; Akaike, Toshihiro

    2013-01-01

    In continuing search for effective treatments of cancer, the emerging model aims at efficient intracellular delivery of therapeutics into tumor cells in order to increase the drug concentration. However, the implementation of this strategy suffers from inefficient cellular uptake and drug resistance. Therefore, pH-sensitive nanosystems have recently been developed to target slightly acidic extracellular pH environment of solid tumors. The pH targeting approach is regarded as a more general strategy than conventional specific tumor cell surface targeting approaches, because the acidic tumor microclimate is most common in solid tumors. When nanosystems are combined with triggered release mechanisms in endosomal or lysosomal acidic pH along with endosomolytic capability, the nanocarriers demonstrated to overcome multidrug resistance of various tumors. Here, novel pH sensitive carbonate apatite has been fabricated to efficiently deliver anticancer drug Doxorubicin (DOX) to cancer cells, by virtue of its pH sensitivity being quite unstable under an acidic condition in endosomes and the desirable size of the resulting apatite-DOX for efficient cellular uptake as revealed by scanning electron microscopy. Florescence microscopy and flow cytometry analyses demonstrated significant uptake of drug (92%) when complexed with apatite nanoparticles. In vitro chemosensitivity assay revealed that apatite-DOX nanoparticles executed high cytotoxicity in several human cancer cell lines compared to free drugs and consequently apatite-DOX-facilitated enhanced tumor inhibitory effect was observed in colorectal tumor model within BALB/cA nude mice, thereby shedding light on their potential applications in cancer therapy. PMID:23613726

  17. Biomimetic self-assembly of apatite hybrid materials: from a single molecular template to bi-/multi-molecular templates.

    PubMed

    Ma, Jun; Wang, Jianglin; Ai, Xin; Zhang, Shengmin

    2014-01-01

    The self-assembly of apatite and proteins is a critical process to induce the formation of the bones and teeth in vertebrates. Although hierarchical structures and biomineralization mechanisms of the mineralized tissues have been intensively studied, most researches focus on the self-assembly biomimetic route using one single-molecular template, while the natural bone is an outcome of a multi-molecular template co-assembly process. Inspired by such a mechanism in nature, a novel strategy based on multi-molecular template co-assembly for fabricating bone-like hybrid materials was firstly proposed by the authors. In this review article we have summarized the new trends from single-molecular template to bi-/multi-molecular template systems in biomimetic fabrication of apatite hybrid materials. So far, many novel apatite hybrid materials with controlled morphologies and hierarchical structures have been successfully achieved using bi-/multi-molecular template strategy, and are found to have multiple common features in comparison with natural mineralized tissues. The carboxyl, carbonyl and amino groups of the template molecules are identified to initiate the nucleation of calcium phosphate during the assembling process. For bi-/multi-molecular templates, the incorporation of multiple promotion sites for calcium and phosphate ions precisely enables to regulate the apatite nucleation from the early stage. The roles of acidic molecules and the synergetic effects of protein templates have been significantly recognized in recent studies. In addition, a specific attention is paid to self-assembling of apatite nanoparticles into ordered structures on tissue regenerative scaffolds due to their promising clinical applications ranging from implant grafts, coatings to drug and gene delivery.

  18. Crystallinity and compositional changes in carbonated apatites: Evidence from {sup 31}P solid-state NMR, Raman, and AFM analysis

    SciTech Connect

    McElderry, John-David P.; Zhu, Peizhi; Mroue, Kamal H.; Xu, Jiadi; Pavan, Barbara; Fang, Ming; Zhao, Guisheng; McNerny, Erin; Kohn, David H.; Franceschi, Renny T.; Holl, Mark M.Banaszak; Tecklenburg, Mary M.J.; Ramamoorthy, Ayyalusamy; Morris, Michael D.

    2013-10-15

    Solid-state (magic-angle spinning) NMR spectroscopy is a useful tool for obtaining structural information on bone organic and mineral components and synthetic model minerals at the atomic-level. Raman and {sup 31}P NMR spectral parameters were investigated in a series of synthetic B-type carbonated apatites (CAps). Inverse {sup 31}P NMR linewidth and inverse Raman PO{sub 4}{sup 3−}ν{sub 1} bandwidth were both correlated with powder XRD c-axis crystallinity over the 0.3–10.3 wt% CO{sub 3}{sup 2−} range investigated. Comparison with bone powder crystallinities showed agreement with values predicted by NMR and Raman calibration curves. Carbonate content was divided into two domains by the {sup 31}P NMR chemical shift frequency and the Raman phosphate ν{sub 1} band position. These parameters remain stable except for an abrupt transition at 6.5 wt% carbonate, a composition which corresponds to an average of one carbonate per unit cell. This near-binary distribution of spectroscopic properties was also found in AFM-measured particle sizes and Ca/P molar ratios by elemental analysis. We propose that this transition differentiates between two charge-balancing ion-loss mechanisms as measured by Ca/P ratios. These results define a criterion for spectroscopic characterization of B-type carbonate substitution in apatitic minerals. - Graphical abstract: Carbonated apatite shows an abrupt change in spectral (NMR, Raman) and morphological (AFM) properties at a composition of about one carbonate substitution per unit cell. Display Omitted - Highlights: • Crystallinity (XRD), particle size (AFM) of carbonated apatites and bone mineral. • Linear relationships among crystallinity, {sup 31}P NMR and Raman inverse bandwidths. • Low and high carbonated apatites use different charge-balancing ion-loss mechanism.

  19. The influence of burial heating on the (U-Th)/He system in apatite: Grand Canyon case study

    NASA Astrophysics Data System (ADS)

    Fox, Matthew; Shuster, David L.

    2014-07-01

    Thermochronological data can constrain the cooling paths of rocks exhumed through the uppermost 1-2 km of earth's crust, and have thus been pivotal in illuminating topographic development over timescales >0.1 Ma. However, in some cases, different methods have led to conflicting conclusions about timing of valley-scale exhumation. Here, we investigate the case of Western Grand Canyon, USA, where different thermochronological datasets have been interpreted to record very different timings of canyon incision (∼70 Ma versus ∼5 Ma). We present a method to assess key assumptions in these constraints and demonstrate that burial heating conditions of basement rocks in the Mesozoic can result in incomplete annealing of radiation damage in apatite. In turn, this has a dramatic effect on the temperature sensitivity of the apatite (U-Th)/He system and its ability to record post-burial exhumation. The possibility of incomplete annealing resolves the apparent conflict in time-temperature paths inferred over the last 70 Ma, although it requires temperatures during burial that are lower than predicted by apatite fission track data. A refinement of parameters that prescribe the kinetics of damage annealing and related control on 4He diffusivity in apatite would account for this discrepancy, specifically if alpha recoil damage anneals at a lower rate than fission tracks at a given temperature. These effects will be important for any application of the apatite (U-Th)/He system in geologic settings that experienced prolonged residence (>10 Ma) between 50-150 °C; the approaches developed here provide means to assess these effects.

  20. A re-evaluation of geological timescale benchmarks and temperature sensitivity of fission-track annealing in apatites

    NASA Astrophysics Data System (ADS)

    Luijendijk, Elco; Andriessen, Paul

    2016-04-01

    Current models of the temperature sensitivity of fission track annealing in apatites have been calibrated using fission track data from boreholes, with the assumption that these samples are currently at maximum burial depth and temperatures. The most detailed data-set comes from boreholes located in the Otway basin, Australia. However, several lines of evidence suggest that these samples are not at their maximum burial depth and temperature and consequently the cooling temperature of the apatite fission track thermochronometer would then be higher than previously assumed. Significant late Cenozoic exhumation in the Otway Basin was suggested by earlier studies that document a major late-Miocene erosional unconformity, folding and trusting of underlying sediments and elevated strandlines along the coast. In addition, anomalously young apatite (U-Th)/He ages in several boreholes in the basin suggest that the basin's sediments have been exhumed and cooled in the late Cenozoic. We explore the effects of late Cenozoic exhumation on fission track data in the Otway basin using a 1D model of burial and thermal history. We show that simulating several 100s of meters of exhumation in the basin results in significant misfit between current annealing models and observed fission track data. The additional exhumation reconciles the Otway basin data with a second detailed fission track dataset from boreholes in Southern Texas with a well-constrained thermal and burial history. We combine vitrinite reflectance data and U-Th/He data from the Otway basin to recalibrate the burial history of the Otway basin. Subsequently we combine the new thermal history of the Otway basin with the Southern Texas dataset to recalibrate the fission track annealing algorithm. The results suggest that fission-track annealing in apatites is underestimated by approximately 20°C by current annealing models, with significant implications for studies that use apatite fission track thermochronology to

  1. Microstructure and electrical conductivity of apatite-type La10Si6-xWxO27+δ electrolytes

    NASA Astrophysics Data System (ADS)

    Xiang, Jun; Ouyang, Jia-Hu; Liu, Zhan-Guo

    2015-06-01

    Different compositions of apatite-type La10Si6-xWxO27+δ ceramics are prepared successfully by the high-temperature solid state reaction route. Crystal structure and electrical properties of La10Si6-xWxO27+δ ceramics are investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS), transmission electron microscopy (TEM) and electrochemical impedance spectroscopy (EIS). La10Si6-xWxO27+δ (x = 0.1, 0.2, 0.3, 0.4, 0.5) ceramics consist of a hexagonal apatite-type structure and a small amount of La6W2O15 phase of orthorhombic structure but no La2SiO5 phase. The diffraction peaks of the hexagonal apatite-type structure shift to the low angle side with doping the W6+. When the content of hexavalent tungsten is beyond 0.1, rod-like grains of La10Si6-xWxO27+δ ceramics are replaced gradually by equiaxed apatite-type grains, and some fine particles of La6W2O15 are observed at grain boundaries. These La6W2O15 particles are non-conducting materials and lead to the increase in grain impedance and grain boundary impedance of La10Si6-xWxO27+δ ceramics gradually when the content of hexavalent tungsten is beyond 0.2. However, the solid solubility of W6+ in the lattice of apatite-type structure reaches the maximum when the W6+ content is at 0.1, and correspondingly the La10Si5.9W0.1O27.1 ceramic has the highest total conductivity of 4.45 × 10-2 S cm-1 at 1073 K.

  2. Possible Roles of Fluoride and Carbonate in Biochemical Carbonated Apatite Formation

    NASA Astrophysics Data System (ADS)

    Meouch, Orysia; Omelon, Sidney

    2016-04-01

    Marine phosphorites are predominantly composed of carbonated fluorapatite (CFA = Ca10-a-b-cNaaMgb(PO4)6-x(CO3)x-y-z(CO3.F)y(SO4)zF2, where x=y+a+2c, and c represents the number of Ca vacancies, with a P2O5 content that ranges from 18-40 %. Sulphur-oxidizing bacteria of the Beggiatoa genus concentration phosphorous as intracellular polyphosphate ((PO3-)n) which is depolymerized into inorganic orthophosphate (Pi). Consequently, an increase in pore water Pi concentration favours carbonated apatite precipitation. The carbonate and fluoride that is characteristic of phosphorite CFA is also located in the vertebrate skeleton. This similarity suggests a biochemical pathway for CFA precipitation. Preliminary Raman spectroscopy and powder x-ray diffraction results that suggest a role for fluoride, and possibly carbonate, in the biochemical depolymerisation of polyphosphates with alkaline phosphatase will be presented.

  3. Fish Canyon Tuff Apatite: A New Look At An Old Low-Temperature Thermochronology Standard

    NASA Astrophysics Data System (ADS)

    Kohn, B. P.; Gleadow, A. J.; Harrison, M.; Lugo-Zazueta, R.

    2011-12-01

    Fish Canyon Tuff (FCT) is one of the most voluminous (>5,000 km3) ignimbrite eruptions documented on Earth. It erupted over a relatively short period from the ~80 km x 30 km La Garita caldera, San Juan volcanic field, Colorado and has served as an important source for geochronology standards, particularly for K-Ar, 40Ar/39Ar and fission track dating [e.g. 1-6]. Ar and U/Pb studies over many years to determine the age of FCT have resulted in disagreement [e.g. 3-5] and this has compromised the potential use of some FCT minerals as geochronology standards. However, a recent study, reporting an improved assessment of the 40K decay constants indicates a 40Ar/39Ar sanidine age of 28.305±0.036 Ma, which can also be reconciled with U/Pb zircon data [6]. In an effort to evaluate the suitability of FCT apatite as a standard for (U-Th-Sm)/He (AHe) thermochronometry we analysed samples from the lithic-rich classic site, some 8.7 km SW of South Fork, Colorado used for early fission track and Ar studies [1-2] and also from a ~330 m vertical section of FCT above that site. Average weighted mean AHe ages (±95% confidence level) from multiple analyses at five sites range from 20.5±1.5 Ma to 23.3±2.2 Ma. Apatite fission track (AFT) ages from the same samples determined by automated image capture and counting, in combination with LA-ICP-MS for U determination, range from 28.4±1.2 Ma at the classic site to 23.3±1.6 Ma at the top of the measured profile. AFT ages can be related to kinetic parameters Dpar and Cl content which are highest (2.19±0.3 μm and 0.73-0.87 wt % respectively) at the classic site, but vary through the profile. AHe and some AFT data provide strong evidence for substantial post-eruptive Early Miocene cooling of the FCT from temperatures estimated between >~80°C to ~110°C, and attributed to km-scale erosion, possibly triggered by structural changes related to formation of the nearby Rio Grande rift. Despite evidence for some later cooling, FCT apatite at

  4. Structural and phase transformation of apatite and quartz in the indentation process single crystals

    SciTech Connect

    Chaikina, Marina

    2014-11-14

    Using the method of scanning and high-resolution electron microscopy, the zones of indentation by scratching for apatite and quartz single crystals were investigated. The textural, structural and phase transformations revealed have been conventionally ascribed to “deformation” and “diffusion” processes of plastic deformation. In zones of indentation by scratching of single crystals there have been two levels of structural transformations revealed, with a sharp boundary between them, at a stress equal to the theoretical ultimate stress limit (σ{sub TSL}). In the top zone of scratches, within the range of stress from the microhardness value H{sub s} up to the σ{sub TSL} value the substance undergoes profound structural and phase transformations. In the bed of scratches at the stress value lower than σ{sub TSL} values, single crystal fragmentation occurs with the formation of blocks and steps.

  5. Intracrystalline rare earth element distributions in apatite: Surface structural influences on incorporation during growth

    NASA Astrophysics Data System (ADS)

    Rakovan, John; Reeder, Richard J.

    1996-11-01

    Intracrystalline REE distributions in fluorapatite have been studied using cathodoluminescence and synchrotron X-ray fluorescence microanalysis (SXRFMA). In the apatite samples studied the [ 10 1 bar 0 ] face grows by the spiral mechanism. As a result, polygonized growth hillocks with three vicinal faces occur on [ 10 1 bar 0 ]; Face symmetry, m, constrains the [011] and [ 01 1 bar ] growth steps to be equivalent. However, [001] steps are not symmetry related. REE and Mn cathodoluminescence qualitatively indicates a differential distribution of Mn 2+ Sm 3+, Eu 3+, Dy 3+, and Eu 2+ between subsectors associated with symmetrically nonequivalent vicinal faces (intrasectoral zoning). SXRFMA shows that the concentrations of all the REEs analyzed (La, Ce, Pr, Nd, Sm, Eu, Gd, Dy, Ho, and Y), except Eu, exhibit a sharp step function, with the change in concentration correlated directly to the boundary between nonequivalent vicinal faces and associated subsectors. Lanthanum, cerium, and praseodymium are enriched in the [001] vicinal subsector, and REEs heavier than Pr, except Eu, are enriched in the <011> vicinal subsectors. The distribution trend observed for Eu may be due to its presence in both the 2+ and 3+ oxidation states. The absence of evidence for anisotropies in step velocity that could influence incorporation supports the proposal of Rakovan and Reeder (1994) that differences in the atomic structure between [001] and <011> steps lead to differential incorporation in apatite. Atomic scale models of the structure of these steps show qualitative differences that are consistent with this proposal. The reversal in the REE partitioning trend between Pr and Nd suggests an ion size effect on the partitioning between nonequivalent steps. The differential distribution of REEs indicates nonequilibrium partitioning. Site specific controls on the partitioning of REEs indicate that partition coefficients can be a function of surface structure and dependent on the spatial

  6. Nanomedicine: Interaction of biomimetic apatite colloidal nanoparticles with human blood components.

    PubMed

    Choimet, Maëla; Hyoung-Mi, Kim; Jae-Min, Oh; Tourrette, Audrey; Drouet, Christophe

    2016-09-01

    This contribution investigates the interaction of two types of biomimetic-apatite colloidal nanoparticles (negatively-charged 47nm, and positively-charged 190nm NPs) with blood components, namely red blood cells (RBC) and plasma proteins, with the view to inspect their hemocompatibility. The NPs, preliminarily characterized by XRD, FTIR and DLS, showed low hemolysis ratio (typically lower than 5%) illustrating the high compatibility of such NPs with respect to RBC, even at high concentration (up to 10mg/ml). The presence of glucose as water-soluble matrix for freeze-dried and re-dispersed colloids led to slightly increased hemolysis as compared to glucose-free formulations. NPs/plasma protein interaction was then followed, via non-specific protein fluorescence quenching assays, by contact with whole human blood plasma. The amount of plasma proteins in interaction with the NPs was evaluated experimentally, and the data were fitted with the Hill plot and Stern-Volmer models. In all cases, binding constants of the order of 10(1)-10(2) were found. These values, significantly lower than those reported for other types of nanoparticles or molecular interactions, illustrate the fairly inert character of these colloidal NPs with respect to plasma proteins, which is desirable for circulating injectable suspensions. Results were discussed in relation with particle surface charge and mean particle hydrodynamic diameter (HD). On the basis of these hemocompatibility data, this study significantly complements previous results relative to the development and nontoxicity of biomimetic-apatite-based colloids stabilized by non-drug biocompatible organic molecules, intended for use in nanomedicine.

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

    NASA Astrophysics Data System (ADS)

    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.

  8. A Sequential Leach Method and Pb Isotope Approach to Studying Apatite Weathering in Granitoid Soils at Hubbard Brook Experimental Forest, NH, USA

    NASA Astrophysics Data System (ADS)

    Nezat, C. A.; Blum, J. D.

    2005-12-01

    Easily dissolved minerals such as calcite and apatite can be important in controlling stream and ground water chemistry even though these minerals are only present in trace amounts in granitoid rocks. Because of its solubility, apatite, a calcium phosphate mineral, may be a significant source of essential nutrients (especially phosphorous) for vegetation, and has been shown to strongly influence stream and soil water composition (e.g, calcium, strontium and rare earth elements). There are additional sources of Ca (e.g., feldspars, hornblende) and P (e.g., organic matter or bound to Fe and Al oxides) in granitoid soils. In order to distinguish the chemical constituents of apatite from other pools in the bulk soil, we selectively dissolved apatite with a dilute acid leach, and measured Pb isotopic ratios of apatite, feldspar, and leachates. We tested the leaching procedure on mineral separates and verified that a dilute nitric solution primarily dissolves apatite. Silicates were dissolved in subsequent steps by successively stronger acids. We then applied this method to bulk soils collected from several soil pits across a small watershed at the Hubbard Brook Experimental Forest (HBEF), New Hampshire, USA, to determine the spatial distribution of Ca and P pools, and determine the depth of apatite depletion in the soil. We also measured Pb isotope ratios in the soil leachates to distinguish among the various sources of Pb (e.g., apatite, feldspars and anthropogenic sources). We found that Pb in the dilute nitric leach of the HBEF organic soils is dominated by anthropogenic sources and that Pb from apatite becomes increasingly important with depth.

  9. Synthesis of trace element bearing single crystals of Chlor-Apatite (Ca5(PO4)3Cl) using the flux growth method

    PubMed Central

    2013-01-01

    We present a new strategy on how to synthesize trace-element bearing (REE, Sr) chlorapatites Ca5(PO4)3Cl using the flux growth method. Synthetic apatites were up to several mm long, light blue in colour. The apatites were characterized using XRD, electron microprobe and laser ablation ICP-MS (LA-ICPMS) techniques and contained several hundred μg/g La, Ce, Pr, Sm, Gd and Lu and about 1700 μg/g Sr. The analyses indicate that apatites were homogenous (within the uncertainties) for major and trace elements. PMID:23531340

  10. Treatability Study Operational Testing Program and Implementation Plan for the Gunite and Associated Tanks at the Oak Ridge National Laboratory, Oak Ridge, Tennessee

    SciTech Connect

    1996-09-01

    To support future decision making of the Gunite and Associated Tanks (GAAT) Operable Unit (OU) remedy selection, the Department of Energy (DOE) is performing a Treatability Study (TS), consistent with the EPA guidance for Comprehensive Environmental Response, compensation, and Liability Act (CERCLA) treatability studies. The study will inform stakeholders about various waste removal technologies and the cost of potential remediation approaches, particularly the cost associated with sluicing and the reduction in risk to human health and the environment from tank content removal. As part of the GAAT OU remedy, a series of studies and technology tests will be preformed. These may address one or more of the following areas, characterization, removal, treatment, and transfer of wastes stored in the GAAT OU.

  11. Reply to comment by Marks et al. (2016) on "Apatite: A new redox proxy for silicic magmas?" [Geochimica et Cosmochimica Acta 132 (2014) 101-119

    NASA Astrophysics Data System (ADS)

    Miles, Andrew; Graham, Colin; Hawkesworth, Chris; Gillespie, Martin; Hinton, Richard; Bromiley, Geoffrey

    2016-06-01

    Marks et al. (2016) investigate the applicability of the Mn-in-apatite oxybarometer proposed by Miles et al. (2014) across a range of magma compositions using published data on well-characterised samples. The authors show that for magma compositions outside of the calc-alkaline and intermediate to silicic range used in the preliminary calibration, fO2 values calculated from Mn-in-apatite vary significantly from independently constrained estimates. These data are used to reiterate our warnings that other controls that are additional to oxygen fugacity are likely to affect Mn partitioning into apatite in some rock types, and particularly so in magmas that lie outside of the range of compositions and conditions used in the calibration. Marks et al. (2016) highlight that temperature may have an especially important effect on Mn partitioning in apatite in some rock types.

  12. Lu-Hf isotope systematics of fossil biogenic apatite and their effects on geochronology

    NASA Astrophysics Data System (ADS)

    Herwartz, Daniel; Münker, Carsten; Tütken, Thomas; Hoffmann, J. Elis; Wittke, Andreas; Barbier, Bruno

    2013-01-01

    Reliable methods for direct dating of biogenic apatite from pre-Pleistocene fossils are currently not available, and recent attempts using the Lu-Hf decay system yielded highly inaccurate ages for both bones and teeth. The geological processes accounting for this poor accuracy of Lu-Hf chronometry are not yet understood. Here we explore Lu-Hf systematics in fossil bones and teeth in detail, by applying five different sample digestion techniques that are tested on bones and composites of bone and sediment. Our current dataset implies that dissolution methods only slightly affect the resulting Lu-Hf ages, while clear differences between the individual digestion techniques became apparent for element concentrations. By analysing the insoluble leftovers from incomplete sample dissolution, four main reservoirs of Hf in fossil bones were identified: (1) a radiogenic end-member associated with apatite; (2) an unradiogenic end-member represented by the authigenic minerals or the embedding sediment; (3) a highly unradiogenic end-member that can be attributed to detrital zircon; and (4) a moderately soluble phase (probably a Zr(Hf)-phosphate) that yielded very low Lu/Hf but a highly radiogenic Hf isotope composition at the same time. This Zr(Hf)-phase must have been precipitated within the fossil bone sample at a late stage of burial history, thereby incorporating radiogenic 176Hf released from apatite surfaces over geological timescales. A second focus of our study is the effect of different sediment matrices and of crystal size on the preservation of pristine Lu-Hf isotope compositions in bioapatite. Because near-depositional Lu-Hf ages of phosphate fossils have previously been reported for the London Clay (England) and a calcareous marl from Tendaguru (Tanzania), we herein investigate specimens fossilised in carbonate matrices (calcareous marl from Oker, Germany; carbonate concretions from the Santana Formation, Brazil; carbonate from the Eifel, Germany) and argillaceous

  13. Waste management plan for phase II of the Bear Creek Valley Treatability study Oak Ridge Y-12 Plant, Oak Ridge, Tennessee

    SciTech Connect

    1997-09-01

    This Waste Management Plan (WMP) for the Bear Creek Valley Treatability Study addresses waste management requirements for the Oak Ridge Y-12 Plant. The study is intended to produce treatment performance data required to design a treatment system for contaminated groundwater. The treatability study will consist of an evaluation of various treatment media including continuous column tests, with up to six columns being employed to evaluate the performance of different media in the treatment of groundwater; an evaluation of the dentrifying capacity and metal uptake capacity of a wetland system; and the long-term dentrifying capacity and metal uptake capacity of algal mats. Additionally, the treatability study involves installation of a trench and incline well to evaluate and assess hydraulic impacts of pumping groundwater. The Sampling and Analysis Plan (SAP) covers the project description, technical objectives, procedures, and planned work activities in greater detail. The Health and Safety Plan (HASP) addresses the health and safety concerns and requirements for the proposed sampling activities. This WMP identifies the types and estimates the volumes of various wastes that may be generated during the proposed treatability studies. The approach to managing waste outlined in this WMP emphasizes the following points: (1) management of the waste generated in a manner that is protective of human health and the environment; (2) minimization of waste generation, thereby reducing unnecessary costs and usage of limited permitted storage and disposal capacities; and (3) compliance with federal, state, and site requirements. Prior sampling at the site has detected organic, radioactive, and metals contamination in groundwater and surface water. Proposed field operations are not expected to result in worker exposures greater than applicable exposure or action limits.

  14. Apatite/Melt Partitioning Experiments Reveal Redox Sensitivity to Cr, V, Mn, Ni, Eu, W, Th, and U

    NASA Technical Reports Server (NTRS)

    Righter, K.; Yang, S.; Humayun, M.

    2016-01-01

    Apatite is a common mineral in terrestrial, planetary, and asteroidal materials. It is commonly used for geochronology (U-Pb), sensing volatiles (H, F, Cl, S), and can concentrate rare earth elements (REE) during magmatic fractionation and in general. Some recent studies have shown that some kinds of phosphate may fractionate Hf and W and that Mn may be redox sensitive. Experimental studies have focused on REE and other lithophile elements and at simplified or not specified oxygen fugacities. There is a dearth of partitioning data for chalcophile, siderophile and other elements between apatite and melt. Here we carry out several experiments at variable fO2 to study the partitioning of a broad range of trace elements. We compare to existing data and then focus on several elements that exhibit redox dependent partitioning behavior.

  15. Vacuum-sintered body of a novel apatite for artificial bone

    NASA Astrophysics Data System (ADS)

    Tamura, Kenichi; Fujita, Tatsushi; Morisaki, Yuriko

    2013-12-01

    We produced regenerative artificial bone material and bone parts using vacuum-sintered bodies of a novel apatite called "Titanium medical apatite (TMA®)" for biomedical applications. TMA was formed by chemically connecting a Ti oxide molecule with the reactive [Ca10(PO4)6] group of Hydroxyapatite (HAp). The TMA powders were kneaded with distilled water, and solid cylinders of compacted TMA were made by compression molding at 10 MPa using a stainless-steel vessel. The TMA compacts were dried and then sintered in vacuum (about 10-3 Pa) or in air using a resistance heating furnace in the temperature range 1073-1773 K. TMA compacts were sintered at temperatures greater than 1073 K, thus resulting in recrystallization. The TMA compact bodies sintered in the range 1273-1773 K were converted into mixtures composed of three crystalline materials: α-TCP (tricalcium phosphate), β-TCP, and Perovskite-CaTiO3. The Perovskite crystals were stable and hard. In vacuum-sintering, the Perovskite crystals were transformed into fibers (approximately 1 µm in diameter × 8 µm in length), and the fiber distribution was uniform in various directions. We refer to the TMA vacuum-sintered bodies as a "reinforced composite material with Perovskite crystal fibers." However, in atmospheric sintering, the Perovskite crystals were of various sizes and were irregularly distributed as a result of the effect of oxygen. After sintering temperature at 1573 K, the following results were obtained: the obtained TMA vacuum-sintered bodies (1) were white, (2) had a density of approximately 2300 kg/m3 (corresponding to that of a compact bone or a tooth), and had a thermal conductivity of approximately 31.3 W/(m·K) (corresponding to those of metal or ceramic implants). Further, it was possible to cut the TMA bodies into various forms with a cutting machine. An implant made of TMA and inserted into a rabbit jaw bone was covered by new bone tissues after just one month because of the high

  16. In-situ Strontium Isotopes Analysis on Single Conodont Apatite by LA-MC-ICP-MS

    NASA Astrophysics Data System (ADS)

    Zhao, L.; Zhang, L.; Chen, Z. Q.; Ma, D.; Qiu, H.; Lv, Z.; Hu, Z.; Wang, F.

    2014-12-01

    Strontium isotope played an important role in stratigraphic chronology and sedimentary geochemistry research (McArthur et al., 2001). Conodonts is a kind of extinct species of marine animals and widely distributed in marine sediments all over the world. Rich in radiogenic Sr contents and difficulty to be affected during diagenesis alteration makes conodonts a good choice in seawater Sr isotope composition studies (John et al., 2008). Conodont samples were collected from 24th to 39th layer across Permian-Triassic boundary at Meishan D section (GSSP), Zhejiang Province, South China (Yin et al., 2001). Conodonts was originated from fresh limestone and only conodont elements with CAI<2 were chosen for in-situ strontium isotope analysis using laser-ablation multi-collector inductively coupled plasma mass spectrometry (LA-MC-ICP-MS). Conodont samples are from totally 25 layers in seven conodont zones making it possible for a high resolution 87Sr/ 86Sr curve reconstruction during the Permian-Triassic transition. 87Sr/ 86Sr ratio kept a relatively high value (0.70752) in the middle part of the Clarkina yini zone and a lower value (0.70634) in the upperpart of Clarkina taylorae zone. Of which, 87Sr/ 86Sr ratio emerged a rapid decrease within the Clarkina taylorae zone. After a subsequent increase, 87Sr/ 86Sr ratio dropped to 0.70777 in the Isarcicella staeschei zone. These results helps providing reference data for the biological mass extinction events during the Permian-Triassic transition. Our study also makes is possible for high resolution 87Sr/ 86Sr ratio testing on the single conodont apatite and riched the in-situ studies on the conodont apatite, which of great significance for the future conodont Sr isotope research (Zhao et al., 2009; Zhao et al., 2013). Keywords: Conodonts, Strontium isotope, LA-MC-ICP-MS, Permian-Triassic transition, Meishan D section [1] John et al., 2008 3P[2] McArthur et al., 2001 J. of Geology [3] Yin et al., 2001 Episodes [4] Zhao et al

  17. Authigenic apatite and octacalcium phosphate formation due to adsorption-precipitation switching across estuarine salinity gradients

    NASA Astrophysics Data System (ADS)

    Oxmann, J. F.; Schwendenmann, L.

    2015-02-01

    Mechanisms governing phosphorus (P) speciation in coastal sediments remain largely unknown due to the diversity of coastal environments and poor analytical specificity for P phases. We investigated P speciation across salinity gradients comprising diverse ecosystems in a P-enriched estuary. To determine P load effects on P speciation we compared the high P site with a low P site. Octacalcium phosphate (OCP), authigenic apatite (carbonate fluorapatite, CFAP) and detrital apatite (fluorapatite) were quantitated in addition to Al/Fe-bound P (Al/Fe-P) and Ca-bound P (Ca-P). Gradients in sediment pH strongly affected P fractions across ecosystems and independent of the site-specific total P status. We found a pronounced switch from adsorbed Al/Fe-P to mineral Ca-P with decreasing acidity from land to sea. This switch occurred at near-neutral sediment pH and has possibly been enhanced by redox-driven phosphate desorption from iron oxyhydroxides. The seaward decline in Al/Fe-P was counterbalanced by the precipitation of Ca-P. Correspondingly, two location-dependent accumulation mechanisms occurred at the high P site due to the switch, leading to elevated Al/Fe-P at pH < 6.6 (landward; adsorption) and elevated Ca-P at pH > 6.6 (seaward; precipitation). Enhanced Ca-P precipitation by increased P loads was also evident from disproportional accumulation of metastable Ca-P (Ca-Pmeta) at the high P site. Here, sediments contained on average 6-fold higher Ca-Pmeta levels compared with the low P site, although these sediments contained only 2-fold more total Ca-P than the low P sediments. Phosphorus species distributions indicated that these elevated Ca-Pmeta levels resulted from transformation of fertilizer-derived Al/Fe-P to OCP and CFAP in nearshore areas. Formation of CFAP as well as its precursor, OCP, results in P retention in coastal zones and can thus lead to substantial inorganic P accumulation in response to anthropogenic P input.

  18. Safety analysis report for the North Tank Farm, Tank W-11, and the Gunite and Associated Tanks -- Treatability Study, Oak Ridge National Laboratory, Oak Ridge, Tennessee

    SciTech Connect

    Platfoot, J.H.

    1997-02-01

    The North Tank Farm (NTF) tanks consist of eight underground storage tanks which have been removed from service because of age and changes in liquid waste system needs and requirements. Tank W-11, which was constructed in 1943, has been removed from service, and contains several hundred gallons of liquid low-level waste (LLLW). The Gunite and Associated Tanks (GAAT) Treatability Study involves the demonstration of sludge removal techniques and equipment for use in other waste storage tanks throughout the Department of Energy (DOE) complex. The hazards associated with the NTF, Tank W-11, and the Treatability Study are identified in hazard identification table in Appendixes A, B, and C. The hazards identified for the NTF, Tank W-11, and the Treatability Study were analyzed in the preliminary hazards analyses (PHA) included as Appendices D and E. The PHA identifies potential accident scenarios and qualitatively estimates the consequences. Because of the limited quantities of materials present in the tanks and the types of energy sources that may result in release of the materials, none of the accidents identified are anticipated to result in significant adverse health effects to on-site or off-site personnel.

  19. Strontium ranelate changes the composition and crystal structure of the biological bone-like apatite produced in osteoblast cell cultures.

    PubMed

    Querido, William; Campos, Andrea P C; Martins Ferreira, Erlon H; San Gil, Rosane A S; Rossi, Alexandre M; Farina, Marcos

    2014-09-01

    We evaluate the effects of strontium ranelate on the composition and crystal structure of the biological bone-like apatite produced in osteoblast cell cultures, a system that gave us the advantage of obtaining mineral samples produced exclusively during treatment. Cells were treated with strontium ranelate at concentrations of 0.05 and 0.5 mM Sr(2+). Mineral substances were isolated and analyzed by using a combination of methods: Fourier transform infrared spectroscopy, solid-state (1)H nuclear magnetic resonance, X-ray diffraction, micro-Raman spectroscopy and energy dispersive X-ray spectroscopy. The minerals produced in all cell cultures were typical bone-like apatites. No changes occurred in the local structural order or crystal size of the minerals. However, we noticed several relevant changes in the mineral produced under 0.5 mM Sr(2+): (1) increase in type-B CO3 (2-) substitutions, which often lead to the creation of vacancies in Ca(2+) and OH(-) sites; (2) incorporation of Sr(2+) by substituting slightly less than 10 % of Ca(2+) in the apatite crystal lattice, resulting in an increase in both lattice parameters a and c; (3) change in the PO4 (3-) environments, possibly because of the expansion of the lattice; (4) the Ca/P ratio of this mineral was reduced, but its (Ca+Sr)/P ratio was the same as that of the control, indicating that its overall cation/P ratio was preserved. Thus, strontium ranelate changes the composition and crystal structure of the biological bone-like apatite produced in osteoblast cell cultures.

  20. Carbonatite melt inclusions in coexisting magnetite, apatite and monticellite in Kerimasi calciocarbonatite, Tanzania: melt evolution and petrogenesis

    NASA Astrophysics Data System (ADS)

    Guzmics, Tibor; Mitchell, Roger H.; Szabó, Csaba; Berkesi, Márta; Milke, Ralf; Abart, Rainer

    2011-02-01

    Kerimasi calciocarbonatite consists principally of calcite together with lesser apatite, magnetite, and monticellite. Calcite hosts fluid and S-bearing Na-K-Ca-carbonate inclusions. Carbonatite melt and fluid inclusions occur in apatite and magnetite, and silicate melt inclusions in magnetite. This study presents statistically significant compositional data for quenched S- and P-bearing, Ca-alkali-rich carbonatite melt inclusions in magnetite and apatite. Magnetite-hosted silicate melts are peralkaline with normative sodium-metasilicate. On the basis of our microthermometric results on apatite-hosted melt inclusions and forsterite-monticellite phase relationships, temperatures of the early stage of magma evolution are estimated to be 900-1,000°C. At this time three immiscible liquid phases coexisted: (1) a Ca-rich, P-, S- and alkali-bearing carbonatite melt, (2) a Mg- and Fe-rich, peralkaline silicate melt, and (3) a C-O-H-S-alkali fluid. During the development of coexisting carbonatite and silicate melts, the Si/Al and Mg/Fe ratio of the silicate melt decreased with contemporaneous increase in alkalis due to olivine fractionation, whereas the alkali content of the carbonatite melt increased with concomitant decrease in CaO resulting from calcite fractionation. Overall the peralkalinity of the bulk composition of the immiscible melts increased, resulting in a decrease in the size of the miscibility gap in the pseudoquaternary system studied. Inclusion data indicate the formation of a carbonatite magma that is extremely enriched in alkalis with a composition similar to that of Oldoinyo Lengai natrocarbonatite. In contrast to the bulk compositions of calciocarbonatite rocks, the melt inclusions investigated contain significant amount of alkalis (Na2O + K2O) that is at least 5-10 wt%. The compositions of carbonatite melt inclusions are considered as being better representatives of parental magma composition than those of any bulk rock.

  1. Changes to the Disordered Phase and Apatite Crystallite Morphology during Mineralization by an Acidic Mineral Binding Peptide from Osteonectin.

    PubMed

    Iline-Vul, Taly; Matlahov, Irina; Grinblat, Judith; Keinan-Adamsky, Keren; Goobes, Gil

    2015-09-14

    Noncollagenous proteins regulate the formation of the mineral constituent in hard tissue. The mineral formed contains apatite crystals coated by a functional disordered calcium phosphate phase. Although the crystalline phase of bone mineral was extensively investigated, little is known about the disordered layer's composition and structure, and less is known regarding the function of noncollagenous proteins in the context of this layer. In the current study, apatite was prepared with an acidic peptide (ON29) derived from the bone/dentin protein osteonectin. The mineral formed comprises needle-shaped hydroxyapatite crystals like in dentin and a stable disordered phase coating the apatitic crystals as shown using X-ray diffraction, transmission electron microscopy, and solid-state NMR techniques. The peptide, embedded between the mineral particles, reduces the overall phosphate content in the mineral formed as inferred from inductively coupled plasma and elemental analysis results. Magnetization transfers between disordered phase species and apatitic phase species are observed for the first time using 2D (1)H-(31)P heteronuclear correlation NMR measurements. The dynamics of phosphate magnetization transfers reveal that ON29 decreases significantly the amount of water molecules in the disordered phase and increases slightly their content at the ordered-disordered interface. The peptide decreases hydroxyl to disordered phosphate transfers within the surface layer but does not influence transfer within the bulk crystalline mineral. Overall, these results indicate that control of crystallite morphology and properties of the inorganic component in hard tissue by biomolecules is more involved than just direct interaction between protein functional groups and mineral crystal faces. Subtler mechanisms such as modulation of the disordered phase composition and structural changes at the ordered-disordered interface may be involved. PMID:26207448

  2. On the mechanism of apatite-induced precipitation on 45S5 glass pellets coated with a natural-derived polymer

    NASA Astrophysics Data System (ADS)

    Araújo, Marco; Miola, Marta; Bertone, Elisa; Baldi, Giovanni; Perez, Javier; Verné, Enrica

    2015-10-01

    In this work, the bioactive glass 45S5 (also known by its commercial name Bioglass®) was successfully dip-coated by a natural derived biopolymer, increasing its apatite-forming ability. The biopolymer was shown to accelerate the first stages of bioactivity, inducing a fast transition to step 4 (formation of amorphous Casbnd P layer) in the apatite-forming ability mechanism. The faster precipitation of Ca/P crystals in the coated samples resulted in the formation of an intermediate amorphous octacalcium phosphate, which later transforms into an apatite layer with high thickness. The effect of the thickness of the coating was also studied on samples coated with polymer suspensions of different concentrations (0.15% and 1.5%, w/v), revealing that the kinetics of formation of the final hydroxycarbonate apatite layer increases with the thickness of the coating. The mechanism by which this apatite-forming ability is accelerated was also investigated, revealing that certain functional groups present in the structure of the polymer allow it to act as an organic matrix and preferential nucleation site for the growth of the hydroxycarbonate apatite layer.

  3. Apatite ore mine tailings as an amendment for remediation of a lead-contaminated shooting range soil.

    PubMed

    Venäläinen, Salla H

    2011-10-01

    This study investigated the use of tailings from apatite ore beneficiation in the remediation of a heavily contaminated shooting range soil. The tailings originating in Siilinjärvi carbonatite complex, Finland, consist of apatite residues accompanied by phlogopite and calcite. In a pot experiment, organic top layer of a boreal forest soil predisposed to pellet-derived lead (Pb) was amended with tailings of various particle-sizes (Ø>0.2mm, Ø<0.2mm and unsieved material) differing in their mineralogical composition. After 9-, 10-, 14- and 21-month incubation, the samples were monitored for tailings-induced changes in the different Pb pools by means of sequential fractionation. Following the incubation, the samples were extracted with water and the extracts were analyzed for Pb species distribution by means of a cation exchange resin. The results revealed that Pb was continuously released from the shotgun pellet fragments due to weathering. However, the apatite and calcite compartments in the tailings counteracted the mobility of the released Pb through the formation of sparingly soluble fluorpyromorphite and cerussite. Furthermore, the tailings efficiently reduced the bioavailability of Pb by transferring it from the water-soluble and exchangeable pools into the organic one. The material also increased the proportion of the less toxic non-cationic Pb to the total dissolved Pb from the initial level of 5% to 9-12%. The results suggest that the tailings-induced stabilization of Pb may be an environmentally sound remediation technique at polluted sites. PMID:21871651

  4. δ18O of apatite phosphate in small pelagic fish: insights from wild-caught and tank-grown specimens

    NASA Astrophysics Data System (ADS)

    Lambert, T.; Javor, B.; Paytan, A.

    2011-12-01

    Oxygen isotope ratios of mineralized structures in fish reflect the temperature and isotopic composition of the water in which they grow. For bulk samples (e.g., whole scales, bones, and otoliths), understanding how this signal is integrated across time and space is critical, especially for organisms exposed to high variability in growth conditions. Here, we assess the response of fish scale δ18O (from apatite phosphate) to experimentally manipulated water conditions. Wild-caught sardines were grown at controlled temperatures (13°C, 17°C, and 21°C) for 11 months. Higher growth temperatures correlated to lower δ18O values, representing a combination of scale apatite deposited before and after the temperature manipulation. Models that account for both biomineral allometry and exposure to varying water properties (e.g., by overlaying migration routes, isoscapes, and temperature maps) have the potential to quantify the varying contributions of minerals grown under different conditions. We use this method to predict δ18O of apatite phosphate for small pelagic fish found in California coastal waters, then compare expected values to those obtained from collected samples. Since phosphate oxygen is relatively resistant to diagenesis, this modern calibration establishes a framework for paleo studies.

  5. Quinone-rich polydopamine functionalization of yttria stabilized zirconia for apatite biomineralization: The effects of coating temperature

    NASA Astrophysics Data System (ADS)

    Zain, Norhidayu Muhamad; Hussain, Rafaqat; Abdul Kadir, Mohammed Rafiq

    2015-08-01

    The use of yttria stabilized zirconia (YSZ) as biomedical implants is often offset by its bioinert nature that prevents its osseointegration to occur. Therefore, the functionalization of YSZ surface by polydopamine to facilitate the biomineralization of apatite layer on top of the coated film has incessantly been studied. In this study YSZ discs were first immersed in 2 mg/mL of stirred dopamine solution at coating temperatures between 25 and 80 °C. The specimens were then incubated for 7d in 1.5 SBF. The effect of coating temperature on the properties (chemical compositions and wettability) and the apatite mineralization on top of the generated films was investigated. It was found that at 50 °C, the specimen displayed the highest intensity of Ca 2p peak (1.55 ± 0.42 cps) with Ca/P ratio of 1.67 due to the presence of abundant quinone groups (Cdbnd O). However, the hydrophilicity (40.9 ± 01.7°) was greatly improved at 60 °C accompanied by the highest film thickness of 306 nm. Therefore, it was concluded that the presence of high intensity of quinone groups (Cdbnd O) in polydopamine film at elevated temperature affects the chelation of Ca2+ ions and thus enhance the growth of apatite layer on top of the functionalized YSZ surface.

  6. Apatite ore mine tailings as an amendment for remediation of a lead-contaminated shooting range soil.

    PubMed

    Venäläinen, Salla H

    2011-10-01

    This study investigated the use of tailings from apatite ore beneficiation in the remediation of a heavily contaminated shooting range soil. The tailings originating in Siilinjärvi carbonatite complex, Finland, consist of apatite residues accompanied by phlogopite and calcite. In a pot experiment, organic top layer of a boreal forest soil predisposed to pellet-derived lead (Pb) was amended with tailings of various particle-sizes (Ø>0.2mm, Ø<0.2mm and unsieved material) differing in their mineralogical composition. After 9-, 10-, 14- and 21-month incubation, the samples were monitored for tailings-induced changes in the different Pb pools by means of sequential fractionation. Following the incubation, the samples were extracted with water and the extracts were analyzed for Pb species distribution by means of a cation exchange resin. The results revealed that Pb was continuously released from the shotgun pellet fragments due to weathering. However, the apatite and calcite compartments in the tailings counteracted the mobility of the released Pb through the formation of sparingly soluble fluorpyromorphite and cerussite. Furthermore, the tailings efficiently reduced the bioavailability of Pb by transferring it from the water-soluble and exchangeable pools into the organic one. The material also increased the proportion of the less toxic non-cationic Pb to the total dissolved Pb from the initial level of 5% to 9-12%. The results suggest that the tailings-induced stabilization of Pb may be an environmentally sound remediation technique at polluted sites.

  7. The structure, bond strength and apatite-inducing ability of micro-arc oxidized tantalum and their response to annealing

    NASA Astrophysics Data System (ADS)

    Wang, Cuicui; Wang, Feng; Han, Yong

    2016-01-01

    In this study, the tantalum oxide coatings were formed on pure tantalum (Ta) by micro-arc oxidation (MAO) in electrolytic solutions of calcium acetate and β-glycerophosphate disodium, and the effect of the applied voltage on the microstructure and bond strength of the MAO coatings was systematically investigated. The effect of annealing treatment on the microstructure, bond strength and apatite-inducing ability of the MAO coatings formed at 350 and 450 V was also studied. The study revealed that during the preparation of tantalum oxide coatings on Ta substrate by MAO, the applied voltage considerably affected the phase components, morphologies and bond strength of the coatings, but had little effect on surface chemical species. After annealing treatment, newly formed CaTa4O11 phase mainly contributed to the much more stronger apatite-inducing ability of the annealed tantalum oxide coatings than those that were not annealed. The better apatite-inducing ability of the MAO coatings formed at 450 V compared to those formed at 350 V was attributed to the less amorphous phase and more crystalline phase as well as more Ca and P contained in the MAO coatings with increasing the applied voltage.

  8. The chitosan prepared from crab tendons: II. The chitosan/apatite composites and their application to nerve regeneration.

    PubMed

    Yamaguchi, Isamu; Itoh, Soichiro; Suzuki, Masumi; Osaka, Akiyoshi; Tanaka, Junzo

    2003-08-01

    The chitosan tubes derived from crab tendons form a hollow tube structure, which is useful for nerve regeneration. However, in order to use the chitosan tubes effectively for nerve regeneration, there remain two problems to be solved. First, the mechanical strength of the tubes is quite high along the longitudinal axis, but is somewhat low for a pressure from side. Second, the chitosan tube walls swell to reduce the inner space of the tubes in vivo. These two problems limit the clinical use of the chitosan tubes. In this study, to solve the problems, apatite was made to react with the chitosan tubes to enhance the mechanical strength of the tube walls. Transmission electron microscopy showed that apatite crystals were formed in the walls of the chitosan tubes. The c-axis of the crystals aligned well in parallel with chitosan molecules. These results indicate that the apatite crystals grow in the tubes starting from the nucleation sites of the chitosan molecules, probably by forming complexes with amino groups of chitosan and calcium ions. Further, the tubes were thermally annealed at 120 degrees C to prevent from swelling, and simultaneously formed into a triangular shape to enhance the stabilization of the tube structure. By these treatments, the hollow tubes could keep their shape even in vivo after implantation. Animal tests using SD rats further showed that the chitosan tubes effectively induced the regeneration of nerve tissue, and were gradually degraded and absorbed in vivo.

  9. Revisiting the localization of Zn2+ cations sorbed on pathological apatite calcifications made through X-ray absorption spectroscopy

    SciTech Connect

    Bazin, D.; Carpentier, X.; Brocheriou, I.; Dorfmuller, P.; Aubert, S.; Chappard, C.; Thiaudiere, D.; Reguer, S.; Waychunas, G.; Jungers, P.; Daudon, M.

    2009-04-01

    The role of oligo-elements such as Zn in the genesis of pathological calcifications is widely debated in the literature. An essential element of discussion is given by their localization either at the surface or within the Ca apatite crystalline network. To determine the localization, X-ray absorption experiments have been performed at SOLEIL. The Exafs results suggest that Zn atoms, present in the Zn{sup 2+} form, are bound to about 4 O atoms at a distance of 2.00{angstrom}, while the interatomic distance R{sub CaO} ranges between 2.35 {angstrom} and 2.71 {angstrom}. Taking into account the content of Zn (around 1000 ppm) and the difference in ionic radius between Zn{sup 2+} (0.074 nm) and Ca{sup 2+} (0.099 nm), a significant longer interatomic distance would be expected in the case of Zn replacing Ca within the apatite crystalline network. We thus conclude that Zn atoms are localized at the surface and not in the apatite nanocrystal structure. Such structural result has essential biological implications for at least two reasons. Some oligoelements have a marked effect on the transformation of chemical phases, and may modify the morphology of crystals. These are both major issues because, in the case of kidney stones, the medical treatment depends strongly on the precise chemical phase and on the morphology of the biological entities at both macroscopic and mesoscopic scales.

  10. Biomimetic apatite sintered at very low temperature by spark plasma sintering: physico-chemistry and microstructure aspects.

    PubMed

    Grossin, David; Rollin-Martinet, Sabrina; Estournès, Claude; Rossignol, Fabrice; Champion, Eric; Combes, Christèle; Rey, Christian; Geoffroy, Chevallier; Drouet, Christophe

    2010-02-01

    Nanocrystalline apatites analogous to bone mineral are very promising materials for the preparation of highly bioactive ceramics due to their unique intrinsic physico-chemical characteristics. Their surface reactivity is indeed linked to the presence of a metastable hydrated layer on the surface of the nanocrystals. Yet the sintering of such apatites by conventional techniques, at high temperature, strongly alters their physico-chemical characteristics and biological properties, which points out the need for "softer" sintering processes limiting such alterations. In the present work a non-conventional technique, spark plasma sintering, was used to consolidate such nanocrystalline apatites at non-conventional, very low temperatures (T<300 degrees C) so as to preserve the surface hydrated layer present on the nanocrystals. The bioceramics obtained were then thoroughly characterized by way of complementary techniques. In particular, microstructural, nanostructural and other major physico-chemical features were investigated and commented on. This work adds to the current international concern aiming at improving the capacities of present bioceramics, in view of elaborating a new generation of resorbable and highly bioactive ceramics for bone tissue engineering.

  11. Conodont apatite δ18O signatures indicate climatic cooling as a trigger of the Late Devonian mass extinction

    NASA Astrophysics Data System (ADS)

    Joachimski, Michael M.; Buggisch, Werner

    2002-08-01

    The oxygen isotopic composition of conodont apatite from two Frasnian-Famennian boundary sections was measured in order to reconstruct variations in marine paleotemperatures during the late Frasnian mass-extinction event. The measured conodont apatite δ18O values reveal two positive excursions with maximum amplitudes of +1‰ to +1.5‰ that parallel positive excursions in the carbonate carbon isotopic composition. The +3‰ excursions in carbonate δ13C have been interpreted as consequences of enhanced organic carbon burial rate resulting in a decrease in atmospheric CO2 concentration. Climatic cooling as a potential consequence of lower atmospheric CO2 concentration is confirmed by the conodont apatite δ18O records, which translate into cooling of low-latitude surface waters by 5 7 °C. Repeated cooling of the low latitudes during the late Frasnian had a severe impact on the tropical shallow-water faunas that were probably adapted to warm surface-water temperatures and severely affected during the late Frasnian crisis. These prominent variations in ocean-water temperature were stressful to the tropical shallow-water fauna and potentially culminated in low origination rates of new species, one of the major factors of the decline in diversity during the latest Frasnian.

  12. In vitro mineralization of bioresorbable poly(ɛ-caprolactone)/apatite composites for bone tissue engineering: a vibrational and thermal investigation

    NASA Astrophysics Data System (ADS)

    Taddei, Paola; Tinti, Anna; Reggiani, Matteo; Fagnano, Concezio

    2005-06-01

    This study was aimed at evaluating the physico-chemical properties of a porous poly(ɛ-caprolactone)/carbonated-apatite (PCL/CAp 30/70 w/w) composite to be used as scaffold for bone tissue engineering. The in vitro degradation mechanism of this matrix in different media was evaluated as well as its bioactivity in a simulated body fluid (SBF) buffered at pH 7.4 (37 °C, 28 days). For this purpose, we used vibrational IR and Raman spectroscopy coupled to thermogravimetry (TG) and differential scanning calorimetry (DSC). The samples were analyzed before and after immersion in the above mentioned solution as well as in 0.01 M NaOH solution (pH=12), saline phosphate buffer at pH 7.4 (SPB) and esterase/SPB. A control PCL sample was analyzed before the addition of the apatitic component. As regards the untreated samples, the method of synthesis utilized for preparing the composite was found to lower the crystallinity degree. The CAp component revealed to be constituted of a B-type CAp with a 3% carbonate content. After immersion in SBF solution, vibrational analysis coupled to TG revealed the deposition of a significant amount of an apatite component on the surface of the PCL/CAp composite as well as in its interior, showing a good in vitro mineralization.

  13. Ca L2,3-edge XANES and Sr K-edge EXAFS study of hydroxyapatite and fossil bone apatite

    NASA Astrophysics Data System (ADS)

    Zougrou, I. M.; Katsikini, M.; Brzhezinskaya, M.; Pinakidou, F.; Papadopoulou, L.; Tsoukala, E.; Paloura, E. C.

    2016-08-01

    Upon burial, the organic and inorganic components of hard tissues such as bone, teeth, and tusks are subjected to various alterations as a result of interactions with the chemical milieu of soil, groundwater, and presence of microorganisms. In this study, simulation of the Ca L 2,3-edge X-ray absorption near edge structure (XANES) spectrum of hydroxyapatite, using the CTM4XAS code, reveals that the different symmetry of the two nonequivalent Ca(1) and Ca(2) sites in the unit cell gives rise to specific spectral features. Moreover, Ca L 2,3-edge XANES spectroscopy is applied in order to assess variations in fossil bone apatite crystallinity due to heavy bacterial alteration and catastrophic mineral dissolution, compared to well-preserved fossil apatite, fresh bone, and geologic apatite reference samples. Fossilization-induced chemical alterations are investigated by means of Ca L 2,3-edge XANES and scanning electron microscopy (SEM) and are related to histological evaluation using optical microscopy images. Finally, the variations in the bonding environment of Sr and its preference for substitution in the Ca(1) or Ca(2) sites upon increasing the Sr/Ca ratio is assessed by Sr K-edge extended X-ray absorption fine structure (EXAFS) spectroscopy.

  14. Apatite, SiO2, rutile and orthopyroxene precipitates in minerals of eclogite xenoliths from Yakutian kimberlites, Russia

    NASA Astrophysics Data System (ADS)

    Alifirova, T. A.; Pokhilenko, L. N.; Korsakov, A. V.

    2015-06-01

    Eclogite mantle xenoliths from the central part of Siberian craton (Udachnaya and Zarnitsa kimberlite pipes) as well as from the northeastern edge of the craton (Obnazhennaya kimberlite) were studied in detail. Garnet and clinopyroxene show evident exsolution textures. Garnet comprises rutile, ilmenite, apatite, and quartz/coesite oriented inclusions. Clinopyroxene contains rutile (± ilmenite) and apatite precipitates. Granular inclusions of quartz in kyanite and garnet usually retain features of their high-pressure origin. According to thermobarometric calculations, the studied eclogitic suite was equilibrated within lithospheric mantle at 3.2-4.9 GPa and 813-1080 °C. The precursor composition of garnets from Udachnaya and Zarnitsa eclogites suggests their stability at depths 210-260 km. Apatite precipitation in clinopyroxenes of Udachnaya and Zarnitsa allows us to declare that original pyroxenes could have been indicative of their high P-T stability. Raman spectroscopic study of quartz and coesite precipitates in garnet porphyroblasts confirms our hypothesis on the origin of the exsolution textures during pressure-temperature decrease. With respect to mineralogical data, we suppose the rocks to be subjected to stepwise decompression and cooling within mantle reservoir.

  15. Seasonal variation of organic matter concentration and characteristics in the Maji ya Chai River (Tanzania): Impact on treatability by ultrafiltration.

    PubMed

    Aschermann, Geert; Jeihanipour, Azam; Shen, Junjie; Mkongo, Godfrey; Dramas, Laure; Croué, Jean-Philippe; Schäfer, Andrea

    2016-09-15

    Many waters in Tanzania exhibit high concentrations of organic matter and dissolved contaminants such as fluoride. Due to bacteria and virus removal, ultrafiltration (UF) is an attractive option for drinking water treatment, and when coupled with adsorbents, may compete with other established processes like nanofiltration (NF) for lower contaminant concentrations. The results presented here examine the characteristics and treatability of tropical natural organic matter (NOM) by UF as a function of seasonal variation. The Tanzanian river Maji ya Chai was sampled monthly during one year. The composition of NOM in Maji ya Chai River is influenced strongly by precipitation. Total organic carbon (TOC), specific ultraviolet absorbance (SUVA) and concentration of allochthonous organics substances (such as humic substances (HS)) are elevated in periods following high precipitation, while TOC is lower and contains more biopolymers in the dry seasons. UF experiments with two regenerated cellulose membranes of different molecular weight cut-off (MWCO, 5 and 10 kDa) were conducted. UF is able to remove 50-95% of TOC with a seasonal variability of 10-20%. Due to the remaining NOM in the water that would contribute to disinfection by-product formation and bacterial regrowth, the physically disinfected water is more applicable for point of use systems than distribution or storage.

  16. Phase 1 report on the Bear Creek Valley treatability study, Oak Ridge Y-12 Plant, Oak Ridge, Tennessee

    SciTech Connect

    1997-04-01

    Bear Creek Valley (BCV) is located within the US Department of Energy (DOE) Oak Ridge Reservation and encompasses multiple waste units containing hazardous and radioactive wastes associated with past operations at the adjacent Oak Ridge Y-12 Plant. The BCV Remedial Investigation determined that disposal of wastes at the S-3 Site, Boneyard/Burnyard (BYBY), and Bear Creek Burial Grounds (BCBG) has caused contamination of both deep and shallow groundwater. The primary contaminants include uranium, nitrate, and VOCs, although other metals such as aluminum, magnesium, and cadmium persist. The BCV feasibility study will describe several remedial options for this area, including both in situ and ex situ treatment of groundwater. This Treatability Study Phase 1 Report describes the results of preliminary screening of treatment technologies that may be applied within BCV. Four activities were undertaken in Phase 1: field characterization, laboratory screening of potential sorbents, laboratory testing of zero valent iron products, and field screening of three biological treatment systems. Each of these activities is described fully in technical memos attached in Appendices A through G.

  17. Portraying mental illness and drug addiction as treatable health conditions: effects of a randomized experiment on stigma and discrimination.

    PubMed

    McGinty, Emma E; Goldman, Howard H; Pescosolido, Bernice; Barry, Colleen L

    2015-02-01

    Despite significant advances in treatment, stigma and discrimination toward persons with mental illness and drug addiction have remained constant in past decades. Prior work suggests that portraying other stigmatized health conditions (i.e., HIV/AIDS) as treatable can improve public attitudes toward those affected. Our study compared the effects of vignettes portraying persons with untreated and symptomatic versus successfully treated and asymptomatic mental illness and drug addiction on several dimensions of public attitudes about these conditions. We conducted a survey-embedded randomized experiment using a national sample (N = 3940) from an online panel. Respondents were randomly assigned to read one of ten vignettes. Vignette one was a control vignette, vignettes 2-5 portrayed individuals with untreated schizophrenia, depression, prescription pain medication addiction and heroin addiction, and vignettes 6-10 portrayed successfully treated individuals with the same conditions. After reading the randomly assigned vignette, respondents answered questions about their attitudes related to mental illness or drug addiction. Portrayals of untreated and symptomatic schizophrenia, depression, and heroin addiction heightened negative public attitudes toward persons with mental illness and drug addiction. In contrast, portrayals of successfully treated schizophrenia, prescription painkiller addiction, and heroin addiction led to less desire for social distance, greater belief in the effectiveness of treatment, and less willingness to discriminate against persons with these conditions. Portrayal of persons with successfully treated mental illness and drug addiction is a promising strategy for reducing stigma and discrimination toward persons with these conditions and improving public perceptions of treatment effectiveness.

  18. Feasibility/treatability studies for removal of heavy metals from training range soils at the Grafenwoehr Training Area, Germany

    SciTech Connect

    Peters, R.W.

    1995-05-01

    A feasibility/treatability study was performed to investigate the leaching potential of heavy metals (particularly lead) from soils at the Grafenw6hr Training Area (GTA) in Germany. The study included an evaluation of the effectiveness of chelant extraction to remediate the heavy-metal-contarninated soils. Batch shaker tests indicated that ethylenediaminetetraacetic acid (EDTA) (0.01M) was more effective than citric acid (0.01M) at removing cadmium, copper, lead, and zinc. EDTA and citric acid were equally effective in mobilizing chromium and barium from the soil. The batch shaker technique with chelant extraction offers promise as a remediation technique for heavy-metal-contaninated soil at the GTA. Columnar flooding tests conducted as part of the study revealed that deionized water was the least effective leaching solution for mobilization of the heavy metals; the maximum solubilization obtained was 3.72% for cadmium. EDTA (0.05M) achieved the greatest removal of lead (average removal of 17.6%). The difficulty of extraction using deionized water indicates that all of the heavy metals are very tightly bound to the soil; therefore, they are very stable in the GTA soils and do not pose a serious threat to the groundwater system. Columnar flooding probably does not represent a viable remediation technique for in-situ cleanup of heavy-metal-contaminated soils at the GTA.

  19. Portraying mental illness and drug addiction as treatable health conditions: effects of a randomized experiment on stigma and discrimination.

    PubMed

    McGinty, Emma E; Goldman, Howard H; Pescosolido, Bernice; Barry, Colleen L

    2015-02-01

    Despite significant advances in treatment, stigma and discrimination toward persons with mental illness and drug addiction have remained constant in past decades. Prior work suggests that portraying other stigmatized health conditions (i.e., HIV/AIDS) as treatable can improve public attitudes toward those affected. Our study compared the effects of vignettes portraying persons with untreated and symptomatic versus successfully treated and asymptomatic mental illness and drug addiction on several dimensions of public attitudes about these conditions. We conducted a survey-embedded randomized experiment using a national sample (N = 3940) from an online panel. Respondents were randomly assigned to read one of ten vignettes. Vignette one was a control vignette, vignettes 2-5 portrayed individuals with untreated schizophrenia, depression, prescription pain medication addiction and heroin addiction, and vignettes 6-10 portrayed successfully treated individuals with the same conditions. After reading the randomly assigned vignette, respondents answered questions about their attitudes related to mental illness or drug addiction. Portrayals of untreated and symptomatic schizophrenia, depression, and heroin addiction heightened negative public attitudes toward persons with mental illness and drug addiction. In contrast, portrayals of successfully treated schizophrenia, prescription painkiller addiction, and heroin addiction led to less desire for social distance, greater belief in the effectiveness of treatment, and less willingness to discriminate against persons with these conditions. Portrayal of persons with successfully treated mental illness and drug addiction is a promising strategy for reducing stigma and discrimination toward persons with these conditions and improving public perceptions of treatment effectiveness. PMID:25528557

  20. Seasonal variation of organic matter concentration and characteristics in the Maji ya Chai River (Tanzania): Impact on treatability by ultrafiltration.

    PubMed

    Aschermann, Geert; Jeihanipour, Azam; Shen, Junjie; Mkongo, Godfrey; Dramas, Laure; Croué, Jean-Philippe; Schäfer, Andrea

    2016-09-15

    Many waters in Tanzania exhibit high concentrations of organic matter and dissolved contaminants such as fluoride. Due to bacteria and virus removal, ultrafiltration (UF) is an attractive option for drinking water treatment, and when coupled with adsorbents, may compete with other established processes like nanofiltration (NF) for lower contaminant concentrations. The results presented here examine the characteristics and treatability of tropical natural organic matter (NOM) by UF as a function of seasonal variation. The Tanzanian river Maji ya Chai was sampled monthly during one year. The composition of NOM in Maji ya Chai River is influenced strongly by precipitation. Total organic carbon (TOC), specific ultraviolet absorbance (SUVA) and concentration of allochthonous organics substances (such as humic substances (HS)) are elevated in periods following high precipitation, while TOC is lower and contains more biopolymers in the dry seasons. UF experiments with two regenerated cellulose membranes of different molecular weight cut-off (MWCO, 5 and 10 kDa) were conducted. UF is able to remove 50-95% of TOC with a seasonal variability of 10-20%. Due to the remaining NOM in the water that would contribute to disinfection by-product formation and bacterial regrowth, the physically disinfected water is more applicable for point of use systems than distribution or storage. PMID:27288671

  1. Metallurgical Laboratory (MetLab) Treatability Study: An Analysis of Passive Soil Vapor Extraction Wells (PSVE) FY1999 Update

    SciTech Connect

    Riha, B.D.

    1999-10-20

    The results to date on the treatability study of the PSVE system at the MetLab of the Savannah River Site (SRS) indicate the technology is performing well. Well concentrations are decreasing and contour maps of the vadose zone soil gas plume show a decrease in the extent of the plume. In the 18 months of operation approximately 200 pounds of chlorinated organic contaminants have been removed by natural barometric pumping of wells fitted with BaroBall valves (low pressure check valves). The mass removal estimates are approximate since the flow rates are estimated, the concentration data is based on exponential fits of a limited data set, and the concentration data is normalized to the average CO2.The concentration values presented in this report should be taken as the general trend or order of magnitude of concentration until longer-term data is collected. These trends are of exponentially decreasing concentration showing the same characteristics as the concentration trends at the SRS Miscellaneous Chemical Basin after three years of PSVE (Riha et. al., 1999).

  2. Extraction and characterisation of apatite- and tricalcium phosphate-based materials from cod fish bones.

    PubMed

    Piccirillo, C; Silva, M F; Pullar, R C; Braga da Cruz, I; Jorge, R; Pintado, M M E; Castro, P M L

    2013-01-01

    Apatite- and tricalcium phosphate-based materials were produced from codfish bones, thus converting a waste by-product from the food industry into high added-valued compounds. The bones were annealed at temperatures between 900 and 1200 °C, giving a biphasic material of hydroxyapatite and tricalcium phosphate (Ca10(PO4)6(OH)2 and β-Ca(PO4)3) with a molar proportion of 75:25, a material widely used in biomedical implants. The treatment of the bones in solution prior to their annealing changed the composition of the material. Single phase hydroxyapatite, chlorapatite (Ca10(PO4)6Cl2) and fluorapatite (Ca10(PO4)6F2) were obtained using CaCl2 and NaF solutions, respectively. The samples were analysed by several techniques (X-ray diffraction, infrared spectroscopy, scanning electron microscopy and differential thermal/thermogravimetric analysis) and by elemental analyses, to have a more complete understanding of the conversion process. Such compositional modifications have never been performed before for these materials of natural origin to tailor the relative concentrations of elements. This paper shows the great potential for the conversion of this by-product into highly valuable compounds for biomedical applications, using a simple and effective valorisation process.

  3. In vivo biocompatibility of custom-fabricated apatite-wollastonite-mesenchymal stromal cell constructs.

    PubMed

    Lee, Jennifer A; Knight, Charlotte A; Kun, Xiao; Yang, Xuebin B; Wood, David J; Dalgarno, Kenneth W; Genever, Paul G

    2015-10-01

    We have used the additive manufacturing technology of selective laser sintering (SLS), together with post SLS heat treatment, to produce porous three dimensional scaffolds from the glass-ceramic apatite-wollastonite (A-W). The A-W scaffolds were custom-designed to incorporate a cylindrical central channel to increase cell penetration and medium flow to the center of the scaffolds under dynamic culture conditions during in vitro testing and subsequent in vivo implantation. The scaffolds were seeded with human bone marrow mesenchymal stromal cells (MSCs) and cultured in spinner flasks. Using confocal and scanning electron microscopy, we demonstrated that MSCs formed and maintained a confluent layer of viable cells on all surfaces of the A-W scaffolds during dynamic culture. MSC-seeded, with and without osteogenic pre-differentiation, and unseeded A-W scaffolds were implanted subcutaneously in MF1 nude mice where osteoid formation and tissue in-growth were observed following histological assessment. The results demonstrate that the in vivo biocompatibility and osteo-supportive capacity of A-W scaffolds can be enhanced by SLS-custom design, without the requirement for osteogenic pre-induction, to advance their potential as patient-specific bone replacement materials.

  4. Innovative Delivery of siRNA to Solid Tumors by Super Carbonate Apatite

    PubMed Central

    Wu, Xin; Yamamoto, Hirofumi; Nakanishi, Hiroyuki; Yamamoto, Yuki; Inoue, Akira; Tei, Mitsuyoshi; Hirose, Hajime; Uemura, Mamoru; Nishimura, Junichi; Hata, Taishi; Takemasa, Ichiro; Mizushima, Tsunekazu; Hossain, Sharif; Akaike, Toshihiro; Matsuura, Nariaki; Doki, Yuichiro; Mori, Masaki

    2015-01-01

    RNA interference (RNAi) technology is currently being tested in clinical trials for a limited number of diseases. However, systemic delivery of small interfering RNA (siRNA) to solid tumors has not yet been achieved in clinics. Here, we introduce an in vivo pH-sensitive delivery system for siRNA using super carbonate apatite (sCA) nanoparticles, which is the smallest class of nanocarrier. These carriers consist simply of inorganic ions and accumulate specifically in tumors, yet they cause no serious adverse events in mice and monkeys. Intravenously administered sCA-siRNA abundantly accumulated in the cytoplasm of tumor cells at 4 h, indicating quick achievement of endosomal escape. sCA-survivin-siRNA induced apoptosis in HT29 tumors and significantly inhibited in vivo tumor growth of HCT116, to a greater extent than two other in vivo delivery reagents. With innovative in vivo delivery efficiency, sCA could be a useful nanoparticle for the therapy of solid tumors. PMID:25738937

  5. Preferential orientation of biological apatite in normal and osteoporotic human vertebral trabeculae

    NASA Astrophysics Data System (ADS)

    Miyabe, S.; Ishimoto, T.; Nakano, T.

    2009-05-01

    The preferential orientation of biological apatite (BAp) is a possible bone quality parameter for the comparison of the bone mechanical property. The preferential BAp orientation undergoes sensitive changes according to the change in the in vivo stress distribution, bone turnover rate etc., resulting in a variation of bone function. Osteoporosis is a metabolic bone disease characterized by reduced bone mass and deterioration of bone microstructure. The effect of osteoporosis on the preferential BAp orientation is however unknown. In this study, a microbeam-X-ray diffraction (μXRD) study was carried out on a trabecula extracted from osteoporotic and normal human vertebral bones and the degree of orientation for the BAp c-axis along its craniocaudal axis was analysed based on our previous report. A micro-computed tomography (μCT) measurement was also performed to analyze trabecular density and structure. In osteoporotic human vertebra, the trabecular number is markedly lower than that in normal vertebra. To sustain increased stress because of bone loss, the primary trabeculae, which are aligned parallel to the craniocaudal axis, tend to selectively remain while the secondary trabeculae, which are perpendicular to the craniocaudal axis, mostly disappear. Moreover, the primary trabecula from osteoporotic vertebra showed a significantly higher degree of BAp prefe