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

International Nuclear Information System (INIS)

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

Deep Vadose Zone Treatability Test of Soil Desiccation for the Hanford Central Plateau: Final Report

Energy Technology Data Exchange (ETDEWEB)

Truex, Michael J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Chronister, Glen B. [CH2M Hill Plateau Remediation Co., Richland, WA (United States); Strickland, Christopher E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Johnson, Christian D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Tartakovsky, Guzel D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Oostrom, Martinus [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Clayton, Ray E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Johnson, Timothy C. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Freedman, Vicky L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Rockhold, Mark L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Greenwood, William J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Peterson, John E. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Hubbard, Susan S. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Ward, Anderson L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

2018-02-20

Some of the inorganic and radionuclide contaminants in the deep vadose zone at the Hanford Site are at depths where direct exposure pathways are not of concern, but may need to be remediated to protect groundwater. The Department of Energy developed a treatability test program for technologies to address Tc-99 and uranium in the deep vadose zone. These contaminants are mobile in the subsurface environment, have been detected at high concentrations deep in the vadose zone, and at some locations have reached groundwater. The treatability test of desiccation described herein was conducted as an element of the deep vadose zone treatability test program. Desiccation was shown to be a potentially effective vadose zone remediation technology to protect groundwater when used in conjunction with a surface infiltration barrier.

Demonstration testing and evaluation of in situ soil heating. Treatability study work plan (Revision 2)

International Nuclear Information System (INIS)

Sresty, G.C.

1994-01-01

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. 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 degrees to 95 degrees 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. This document is a Treatability Study Work Plan for the demonstration program. The document contains a description of the proposed treatability study, background of the EM heating process, description of the field equipment, and demonstration test design

Hanford 100-D Area Biostimulation Treatability Test Results

Energy Technology Data Exchange (ETDEWEB)

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.

Soil washing treatability study

International Nuclear Information System (INIS)

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

Firm contracts for treatability tests on contaminated soils

International Nuclear Information System (INIS)

Anon.

1989-01-01

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

Apatite Biominerals

Directory of Open Access Journals (Sweden)

Christèle Combes

2016-04-01

Full Text Available Calcium phosphate apatites offer outstanding biological adaptability that can be attributed to their specific physico-chemical and structural properties. The aim of this review is to summarize and discuss the specific characteristics of calcium phosphate apatite biominerals in vertebrate hard tissues (bone, dentine and enamel. Firstly, the structural, elemental and chemical compositions of apatite biominerals will be summarized, followed by the presentation of the actual conception of the fine structure of synthetic and biological apatites, which is essentially based on the existence of a hydrated layer at the surface of the nanocrystals. The conditions of the formation of these biominerals and the hypothesis of the existence of apatite precursors will be discussed. Then, we will examine the evolution of apatite biominerals, especially during bone and enamel aging and also focus on the adaptability of apatite biominerals to the biological function of their related hard tissues. Finally, the diagenetic evolution of apatite fossils will be analyzed.

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

International Nuclear Information System (INIS)

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

In situ respiration testing: A field treatability test for bioventing

International Nuclear Information System (INIS)

Kittel, J.A.; Hinchee, R.E.; Miller, R.; Vogel, C.; Hoeppel, R.

1993-01-01

Bioventing is the process of aerating subsurface soils to stimulate in situ biological activity and promote bioremediation. Bioventing differs from soil venting in remedial approach. Soil venting is designed and operated to maximize the volatilization of low-molecular-weight compounds, with some biodegradation occurring. In contrast, bioventing is designed to maximize biodegradation of aerobically biodegradable compounds, regardless of their molecular weight, with some volatilization occurring. Bioventing is gaining wide acceptance as a remediation alternative at petroleum-contaminated sites. However, site variability usually requires that a short term treatability test be conducted in situ at potential sites to determine the applicability of bioventing. Battelle has worked with the US Air Force and the US Navy to develop a simple and inexpensive field test to evaluate bioventing potential-contaminated sites. This test has been used to evaluate the applicability of bioventing at over 50 sites. The in situ respiration test consists of injecting air and an inert tracer gas (helium) over a 24-hour period to aerate soils at an oxygen-deficient, petroleum-contaminated site. Soil vapor samples are collected to determine oxygen utilization rates and carbon dioxide production rates. The stoichiometric relationship for the oxidation of hexane is used to calculate the biodegradation rate. The tracer gas is monitored to estimate the effect of diffusion on changes in soil-gas concentrations

Evaporative oxidation treatability test report

International Nuclear Information System (INIS)

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

In situ vitrification program treatability investigation progress report

International Nuclear Information System (INIS)

Arrenholz, D.A.

1991-02-01

This document presents a summary of the efforts conducted under the in situ vitrification treatability study during the period from its initiation in FY-88 until FY-90. In situ vitrification is a thermal treatment process that uses electrical power to convert contaminated soils into a chemically inert and stable glass and crystalline product. Contaminants present in the soil are either incorporated into the product or are pyrolyzed during treatment. The treatability study being conducted at the Idaho National Engineering Laboratory by EG ampersand G Idaho is directed at examining the specific applicability of the in situ vitrification process to buried wastes contaminated with transuranic radionuclides and other contaminants found at the Subsurface Disposal Area of the Radioactive Waste Management Complex. This treatability study consists of a variety of tasks, including engineering tests, field tests, vitrified product evaluation, and analytical models of the in situ vitrification process. 6 refs., 4 figs., 3 tabs

Soil washing treatability testing for rad-waste material

International Nuclear Information System (INIS)

Leis, K.S.; Lear, P.R.

1997-01-01

Soil washing treatability testing was successfully completed on soil contaminated with Ra-226 and Th-232. The objective of the soil washing study was to determine if the radiologically contaminated fraction of the soil could be separated from the bulk of the soil material. The cleanup criteria was 38 microm) fraction was allowed to settle and was washed to separate it from the highly contaminated fine (< 38 microm) fraction. The clean coarse fraction comprised 85.7% of the total solids and had less than 15 pCi/g of Ra-226 and Th-232. This material was to be disposed at a RCRA Subtitle D disposal facility. The suspended fines were flocculated and dewatered to minimize the amount of highly contaminated material produced by the soil washing. The dewatered fines would require disposal at a low-level radiological disposal facility. Mass balance calculations were made to determine production rates and chemical and equipment requirements for the full-scale soil washing treatment

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

Science.gov (United States)

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

Laboratory treatability studies preparatory to field testing a resting-cell in situ microbial filter bioremediation strategy

International Nuclear Information System (INIS)

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

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

Energy Technology Data Exchange (ETDEWEB)

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.

LABORATORY SCALE STEAM INJECTION TREATABILITY STUDIES

Science.gov (United States)

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...

Preparation of mica/apatite glass-ceramics biomaterials

International Nuclear Information System (INIS)

Liu Yong; Sheng Xiaoxian; Dan Xiaohong; Xiang Qijun

2006-01-01

Glass-ceramics have become more and more important biomaterials. In this work mica glass/apatite composites with various compositions were prepared by casting and subsequent heat treatments. The effects of composition, phase constitution and crystallinity on mechanical properties, including elastic modulus and transverse rupture strength (TRS), were investigated by using X-ray diffraction analyses (XRD), scanning electron microscopy (SEM) and mechanical tests. Results show that addition of apatite composition in mica glass accelerates the crystallization process and induces the formation of fluoroapatite phase, and the nucleation of apatite crystals occurs before that of mica crystals. The fuoroapatite in this work is needle-like, which is almost the same to that in human bone. The transverse rupture strength increases with the content of fluoroapatite and the crystallinity increasing, except that at a low apatite content the mechanical properties are lower than those of mica glass under the same processing conditions. The transverse rupture strength and elastic modulus obtained in this work fall in the range of those of human bone. SBF immersion test demonstrates good bioactivity of this biomaterial

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

Energy Technology Data Exchange (ETDEWEB)

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.

Treatability study sample exemption: update

International Nuclear Information System (INIS)

1997-01-01

This document is a RCRA Information Brief intended to update the information in the 1991 Small-Scale Treatability Study Information Brief, and to address questions about the waste and treatability study sample exemptions that have arisen since References 3 and 5 were published

Iodine immobilization in apatites

International Nuclear Information System (INIS)

Audubert, F.; Lartigue, J.E.

2000-01-01

In the context of a scientific program on long-lived radionuclide conditioning, a matrix for iodine 129 immobilization has been studied. A lead vanado-phosphate apatite was prepared from the melt of lead vanado-phosphate Pb 3 (VO 4 ) 1.6 (PO 4 ) 0.4 and lead iodide PbI 2 in stoichiometric proportions by calcination at 700 deg. C during 3 hours. Natural sintering of this apatite is not possible because the product decomposition occurs at 400 deg. C. Reactive sintering is the solution. The principle depends on the coating of lead iodide with lead vanado-phosphate. Lead vanado-phosphate coating is used as iodo-apatite reactant and as dense covering to confine iodine during synthesis. So the best condition to immobilize iodine during iodo-apatite synthesis is a reactive sintering at 700 deg. C under 25 MPa. We obtained an iodo-apatite surrounded with dense lead vanadate. Leaching behaviour of the matrix synthesized by solid-solid reaction is under progress in order to determine chemical durability, basic mechanisms of the iodo-apatite alteration and kinetic rate law. Iodo-apatite dissolution rates were pH and temperature dependent. We obtained a rate of 2.5 10 -3 g.m -2 .d -1 at 90 deg. C in initially de-ionised water. (authors)

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

Energy Technology Data Exchange (ETDEWEB)

Truex, Michael J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Oostrom, Martinus [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Strickland, Christopher E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Johnson, Timothy C. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Johnson, Christian D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Clayton, Ray E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Chronister, Glen B. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

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.

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

Directory of Open Access Journals (Sweden)

van Karnebeek Clara D M

2012-07-01

Full Text Available Abstract 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

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

Science.gov (United States)

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

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

Energy Technology Data Exchange (ETDEWEB)

Truex, Michael J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Strickland, Christopher E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Oostrom, Martinus [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Johnson, Christian D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Tartakovsky, Guzel D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Johnson, Timothy C. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Clayton, Ray E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Chronister, Glen B. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

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.

Treatability Test Report For The Removal Of Chromium From Groundwater At 100-D Area Using Electrocoagulation

International Nuclear Information System (INIS)

Petersen, S.W.

2009-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

Apatite glass-ceramics: a review

Science.gov (United States)

Duminis, Tomas; Shahid, Saroash; Hill, Robert Graham

2016-12-01

This article is a review of the published literature on apatite glass-ceramics (GCs). Topics covered include crystallization mechanisms of the various families of the apatite GCs and an update on research and development on apatite GCs for applications in orthopedics, dentistry, optoelectronics and nuclear waste management. Most apatite GCs crystallize through a homogenous nucleation and crystallization mechanism, which is aided by a prior liquid-liquid phase separation. Careful control of the base glass composition and heat-treatment conditions, which determine the nature and morphology of the crystal phases in the GC can produce GC materials with exceptional thermal, mechanical, optical and biological properties. The GCs reviewed for orthopedic applications exhibit suitable mechanical properties and can chemically bond to bone and stimulate its regeneration. The most commercially successful apatite GCs are those developed for dental veneering. These materials exhibit excellent translucency and clinical esthetics, and mimic the natural tooth mineral. Due to the ease of solid solution of the apatite lattice, rare earth doped apatite GCs are discussed for potential applications in optoelectronics and nuclear waste management. One of the drawbacks of the commercial apatite GCs used in orthopedics is the lack of resorbability, therefore the review provides a direction for future research in the field.

In situ vitrification program treatability investigation progress report

International Nuclear Information System (INIS)

Arrenholz, D.A.

1990-12-01

This document presents a summary of the efforts conducted under the in situ vitrification treatability study during the period from its initiation in FY-88 until FY-90. In situ vitrification is a thermal treatment process that uses electrical power to convert contaminated soils into a chemically inert and stable glass and crystalline product. Contaminants present in the soil are either incorporated into the product or are pyrolyzed during treatment. The treatability study being conducted at the Idaho National Engineering Laboratory by EG ampersand G Idaho is directed at examining the specific applicability of the in situ vitrification process to buried wastes contaminated with transuranic radionuclides and other contaminants found at the Subsurface Disposal Area of the Radioactive Waste Management Complex. This treatability study consists of a variety of tasks, including engineering tests, field tests, vitrified product evaluation, and analytical models of the ISV process. The data collected in the course of these efforts will address the nine criteria set forth in the Comprehensive Environmental Response, Compensation, and Liability Act, which will be used to identify and select specific technologies to be used in the remediation of the buried wastes at the Subsurface Disposal Area. 6 refs., 4 figs., 3 tabs

Safety assessment for the 118-B-1 Burial Ground excavation treatability tests. Revision 2

International Nuclear Information System (INIS)

Zimmer, J.J.; Frain, J.M.

1994-12-01

This revision of the Safety Assessment provides an auditable safety analysis of the hazards for the proposed treatability test activities per DOE-EM-STD-5502-94, DOE Limited Standard, Hazard Baseline Documentation (DOE 1994). The proposed activities are classified as radiological activities and as such, no longer require Operational Safety Limits (OSLs). The OSLS, Prudent Actions, and Institutional and Organization Controls have been removed from this revision and replaced with ''Administrative Actions Important to Safety,'' as determined by the hazards analysis. Those Administrative Actions Important to Safety are summarized in Section 1.1, ''Assessment Summary.''

Evaluation of fall chinook salmon spawning adjacent to the In-Situ Redox Manipulation treatability test site, Hanford Site, Washington

International Nuclear Information System (INIS)

Mueller, R.P.; Geist, D.R.

1998-10-01

The In Situ Redox Manipulation (ISRM) experiment is being evaluated as a potential method to remove contaminants from groundwater adjacent to the Columbia River near the 100-D Area. The ISRM experiment involves using sodium dithionate (Na 2 O 6 S 2 ) to precipitate chromate from the groundwater. The treatment will likely create anoxic conditions in the groundwater down-gradient of the ISRM treatability test site; however, the spatial extent of this anoxic plume is not exactly known. Surveys were conducted in November 1997, following the peak spawning of fall chinook salmon. Aerial surveys documented 210 redds (spawning nests) near the downstream island in locations consistent with previous surveys. Neither aerial nor underwater surveys documented fall chinook spawning in the vicinity of the ISRM treatability test site. Based on measurements of depth, velocity, and substrate, less than 1% of the study area contained suitable fall chinook salmon spawning habitat, indicating low potential for fall chinook salmon to spawn in the vicinity of the ISRM experiment

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

Science.gov (United States)

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

2015-12-01

higher temperatures than fission-track damage and the impact on coupled apatite He and AFT dates is magnified for protracted cooling histories. Further experimental and field-based tests are important for refining radiation damage and fission-track annealing parameters for accurate interpretation of apatite He- and AFT-derived thermal histories.

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

Energy Technology Data Exchange (ETDEWEB)

Deng, Yi [Department of Oral and Maxillofacial Surgery, Laboratory of Interdisciplinary Studies, School and Hospital of Stomatology, Peking University, Beijing 100081 (China); Center for Biomedical Materials and Tissue Engineering, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871 (China); Sun, Yuhua [Department of Oral and Maxillofacial Surgery, Laboratory of Interdisciplinary Studies, School and Hospital of Stomatology, Peking University, Beijing 100081 (China); Chen, Xiaofang [Center for Biomedical Materials and Tissue Engineering, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871 (China); Zhu, Peizhi, E-mail: pzzhu@umich.edu [Center for Biomedical Materials and Tissue Engineering, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871 (China); Department of Chemistry, University of Michigan, Ann Arbor, MI 48109-1055 (United States); Wei, Shicheng, E-mail: sc-wei@pku.edu.cn [Department of Oral and Maxillofacial Surgery, Laboratory of Interdisciplinary Studies, School and Hospital of Stomatology, Peking University, Beijing 100081 (China); Center for Biomedical Materials and Tissue Engineering, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871 (China)

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. - Highlights: • Heparin was used as a template to synthesize needle-shaped nano-apatite. • Changing the pH value and concentration led to different properties of apatite. • Apatite prepared by heparin was more favorable to the osteogenic differentiation. • Possible synthesis mechanism of apatite templated by heparin was described.

Calcium phosphate nuclear materials: apatitic ceramics for separated wastes

International Nuclear Information System (INIS)

Carpena, J.; Lacout, J.L.

2005-01-01

Is it feasible to elaborate conditioning materials for separated high activity nuclear wastes, as actinides or fission products? Specific materials have been elaborated so that the waste is incorporated within the crystalline structure of the most stable calcium phosphate, i.e. apatite. This mineral is able to sustain high irradiation doses assuming a well chosen chemical composition. Mainly two different ways of synthesis have been developed to produce hard apatite ceramics that can be used to condition nuclear wastes. Here we present a data synthesis regarding the elaboration of these apatite nuclear materials that includes experiments on crystallo-chemistry, chemical analysis, leaching and irradiation tests performed for the past fifteen years. (authors)

Draft Technical Protocol: A Treatability Test for Evaluating the Potential Applicability of the Reductive Anaerobic Biological in Situ Treatment Technology (Rabitt) to Remediate Chloroethenes

National Research Council Canada - National Science Library

Morse, Jeff

1998-01-01

This draft, unvalidated protocol describes a comprehensive approach for conducting a phased treatability test to determine the potential for employing the Reductive Anaerobic Biological In Situ Treatment Technology (RABITT...

Bench-scale treatability testing of biological, UV oxidation, distillation, and ion-exchange treatment of trench water from a low-level radioactive waste disposal area at West Valley, New York

Energy Technology Data Exchange (ETDEWEB)

Sundquist, J.A.; Gillings, J.C. [Ecology and Environment, Inc. (United States); Sonntag, T.L. [New York State Energy Research and Development Authority (United States); Denault, R.P. [Pacific Nuclear, Inc. (United States)

1993-03-01

Ecology and Environment, Inc. (E and E), under subcontract to Pacific Nuclear Services (PNS), conducted for the New York State Energy Research and Development Authority (NYSERDA) treatability tests to support the selection and design of a treatment system for leachate from Trench 14 of the West Valley State-Licensed, Low-Level Radioactive Waste Disposal Area (SDA). In this paper E and E presents and discusses the treatability test results and provides recommendations for the design of the full-scale treatment system.

Pad A Treatability Study long-range project plan

International Nuclear Information System (INIS)

Mousseau, J.D.

1991-08-01

The purpose of the Pad A Treatability Study Project is to identify and demonstrate through lab- and pilot-scale testing, technologies for treating plutonium-contaminated salt waste. This document presents proposed objectives and schedules, scope of work and breakdown structure, cost elements, deployment, benefits, and change controls for the project

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

Energy Technology Data Exchange (ETDEWEB)

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

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

International Nuclear Information System (INIS)

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

Treatability Study Operational Testing Program and Implementation Plan for the Gunite and Associated Tanks at the Oak Ridge National Laboratory, Oak Ridge, Tennessee

International Nuclear Information System (INIS)

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

Treatability Study Operational Testing Program and Implementation Plan for the Gunite and Associated Tanks at the Oak Ridge National Laboratory, Oak Ridge, Tennessee

Energy Technology Data Exchange (ETDEWEB)

NONE

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.

WASTE TREATMENT PLANT (WTP) LIQUID EFFLUENT TREATABILITY EVALUATION

International Nuclear Information System (INIS)

LUECK, K.J.

2004-01-01

A forecast of the radioactive, dangerous liquid effluents expected to be produced by the Waste Treatment Plant (WTP) was provided by Bechtel National, Inc. (BNI 2004). The forecast represents the liquid effluents generated from the processing of Tank Farm waste through the end-of-mission for the WTP. The WTP forecast is provided in the Appendices. The WTP liquid effluents will be stored, treated, and disposed of in the Liquid Effluent Retention Facility (LERF) and the Effluent Treatment Facility (ETF). Both facilities are located in the 200 East Area and are operated by Fluor Hanford, Inc. (FH) for the US. Department of Energy (DOE). The treatability of the WTP liquid effluents in the LERF/ETF was evaluated. The evaluation was conducted by comparing the forecast to the LERF/ETF treatability envelope (Aromi 1997), which provides information on the items which determine if a liquid effluent is acceptable for receipt and treatment at the LERF/ETF. The format of the evaluation corresponds directly to the outline of the treatability envelope document. Except where noted, the maximum annual average concentrations over the range of the 27 year forecast was evaluated against the treatability envelope. This is an acceptable approach because the volume capacity in the LERF Basin will equalize the minimum and maximum peaks. Background information on the LERF/ETF design basis is provided in the treatability envelope document

Pilot-scale treatability test plan for the 100-HR-3 operable unit

International Nuclear Information System (INIS)

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

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

Energy Technology Data Exchange (ETDEWEB)

Iafisco, Michele, E-mail: michele.iafisco@istec.cnr.it; 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, CO{sub 3} 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 CO{sub 3} 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–CO{sub 3}-apatite. Indeed, incorporation of lower quantity of Sr did not induce considerable variations in the chemical structure of Mg–CO{sub 3}-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 PO{sub 4}. 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. - Highlights: • Biomimetic nanocrystalline apatites co-substituted with Mg, CO{sub 3} and Sr were prepared. • Biological-like amounts of Mg and CO{sub 3} were inserted to mimic the composition of bone apatite. • The addition of increasing

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

International Nuclear Information System (INIS)

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

2014-01-01

The present work investigates the preparation of biomimetic nanocrystalline apatites co-substituted with Mg, CO 3 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 CO 3 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–CO 3 -apatite. Indeed, incorporation of lower quantity of Sr did not induce considerable variations in the chemical structure of Mg–CO 3 -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 PO 4 . 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. - Highlights: • Biomimetic nanocrystalline apatites co-substituted with Mg, CO 3 and Sr were prepared. • Biological-like amounts of Mg and CO 3 were inserted to mimic the composition of bone apatite. • The addition of increasing quantities of Sr (from 0 to 12

BIOMINERALOGICAL INVESTIGATION OF APATITE PIEZOELECTRICITY

Directory of Open Access Journals (Sweden)

M. Pawlikowski

2016-01-01

Full Text Available Investigation of apatite piezoelectricity was conducted in order to assess piezoelectric properties of bone. In the first stage, mineralogical analysis of different apatite crystals, regarding their purity and fitness for the experiments was performed. After the crystals had been chosen, 0.8 mm-thick plates were cut, perpendicular and parallel to the crystallographic Z axis. The plates were then polished and dusted with gold. Electrodes were attached to the opposite surfaces of the plates with conductive glue. So prepared plates were hooked up to the EEG machine used for measuring electrical activity in the brain. The plates were then gently tapped to observe and register currents generated in them. Acquired data was processed by subtracting from the resulting graphs those generated by a hand movement, without tapping the plate. Results indicate that apatite plates have weak piezoelectric properties. Observed phenomenon may be translated to bone apatite, which would explain, at least partially, piezoelectric properties of bone. Acquired results suggest that there is a relation between the mechanical workload of bones (bone apatite and theirelectrical properties. Considering the massive internal surface of bones, they may be treated as a kind of internal “antenna” reacting not only to mechanical stimuli, but to changes in electromagnetic field as well. Observed phenomena no doubt significantly influence the biological processes occurring in bones and the whole human body.

Preliminary characterization of calcium chemical environment in apatitic and non-apatitic calcium phosphates of biological interest by X-ray absorption spectroscopy

International Nuclear Information System (INIS)

Eichert, D.; Salome, M.; Banu, M.; Susini, J.; Rey, C.

2005-01-01

Several reports have mentioned the existence of non-apatitic environments of phosphate and carbonate ions in synthetic and biological poorly crystalline apatites. However there were no direct spectroscopic evidences for the existence of non-apatitic environment of calcium ions. X-ray Absorption Spectroscopy, at the K-edge of calcium, allows the discrimination between different calcium phosphates of biological interest despite great spectral similarities. A primary analysis of the spectra reveals the existence, in synthetic poorly crystalline apatites, of variable features related to the maturation stage of the sample and corresponding to the existence of non-apatitic environments of calcium ions. Although these features can also be found in several other calcium phosphate salts, and do not allow a clear identification of the ionic environments of calcium ions, they give a possibility to directly determine the maturity of poorly crystalline apatite from calcium X-ray Absorption Near Edge Structure spectra

Drinking Water Treatability Database (TDB)

Data.gov (United States)

U.S. Environmental Protection Agency — The Drinking Water Treatability Database (TDB) presents referenced information on the control of contaminants in drinking water. It allows drinking water utilities,...

Waste Treatment Plant Liquid Effluent Treatability Evaluation

International Nuclear Information System (INIS)

LUECK, K.J.

2001-01-01

Bechtel National, Inc. (BNI) provided a forecast of the radioactive, dangerous liquid effluents expected to be generated by the Waste Treatment Plant (WTP). The forecast represents the liquid effluents generated from the processing of 25 distinct batches of tank waste through the WTP. The WTP liquid effluents will be stored, treated, and disposed of in the Liquid Effluent Retention Facility (LERF) and the Effluent Treatment Facility (ETF). Fluor Hanford, Inc. (FH) evaluated the treatability of the WTP liquid effluents in the LERFIETF. The evaluation was conducted by comparing the forecast to the LERFIETF treatability envelope, which provides information on the items that determine if a liquid effluent is acceptable for receipt and treatment at the LERFIETF. The WTP liquid effluent forecast is outside the current LERFlETF treatability envelope. There are several concerns that must be addressed before the WTP liquid effluents can be accepted at the LERFIETF

RBS and RNRA studies on sorption of europium by apatite

Energy Technology Data Exchange (ETDEWEB)

Ohnuki, Toshihiko; Kozai, Naofumi; Isobe, Hiroshi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Murakami, Takashi; Yamamoto, Shunya; Aoki, Yasushi; Naramoto, Hiroshi

1997-03-01

The sorption mechanism of europium, alternative of trivalent TRU has been studied based on the depth profiles of elements obtained by Rutherford Backscattering Spectroscopy (RBS) and Resonant Nuclear Reaction Analysis (RNRA). The positive peak for Eu and the negative peak for Ca were observed in the subtracted RBS spectra of the apatites on which Eu was sorbed from that of the fresh apatite. This indicates that Eu was sorbed on apatite, while a fraction of Ca was released from apatite. The peak height for Eu in the RBS spectrum of the apatite obtained at 75degC was higher than that of the apatite at 40degC. The depth profile of hydrogen of the apatite on which Eu was sorbed was similar to that of the fresh apatite. The concentration of Eu in the solution decreased with increasing temperature. On the contrary, the concentration of Ca increased with increasing temperature. Thus, it is concluded that a fraction of Eu is exchanged for Ca in the structure of apatite. (author)

Waste treatability guidance program. User's guide. Revision 0

International Nuclear Information System (INIS)

Toth, C.

1995-01-01

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

Insight into Biological Apatite: Physiochemical Properties and Preparation Approaches

Directory of Open Access Journals (Sweden)

Quan Liu

2013-01-01

Full Text Available 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.

Bio-inspired citrate functionalized apatite coating on rapid prototyped titanium scaffold

Energy Technology Data Exchange (ETDEWEB)

Yu, Peng [National engineering research center for tissue restoration and reconstruction, South China University of Technology, Guangzhou 510641 (China); Lu, Fang [School of Chinese Materia Medica, Guangzhou University of Chinese Medicine, Guangzhou 510006 (China); Zhu, Wenjun [Department of Prosthodontics, Guanghua School of Stomatology, Guang Dong Key Laboratory of Stomatology, Sun Yat-sen University, Guangzhou 510055 (China); Wang, Di [National engineering research center for tissue restoration and reconstruction, South China University of Technology, Guangzhou 510641 (China); Zhu, Xiaojing [Department of Prosthodontics, Guanghua School of Stomatology, Guang Dong Key Laboratory of Stomatology, Sun Yat-sen University, Guangzhou 510055 (China); Tan, Guoxin, E-mail: tanguoxin@126.com [Institute of Chemical Engineering and Light Industry, Guangdong University of Technology, Guangzhou 510006 (China); Wang, Xiaolan [National engineering research center for tissue restoration and reconstruction, South China University of Technology, Guangzhou 510641 (China); Zhang, Yu; Li, Lihua [General Hospital of Guangzhou Military Command of PLA, Guangzhou 510010 (China); Ning, Chengyun, E-mail: imcyning@scut.edu.cn [National engineering research center for tissue restoration and reconstruction, South China University of Technology, Guangzhou 510641 (China)

2014-09-15

Highlights: • Designed and reproducible porous titanium scaffolds were produced. • Hydrophilic nanoporous film was built on scaffold. • Apatite coating was deposited on scaffold under the modulation of citrate ions. • Citrate ions could affect CO{sub 3}{sup 2−} incorporation in apatite coatings. - Abstract: Scaffold functionalized with appropriate osteogenic coatings can significantly improve implant-bone response. In this study, with designed model and optimized manufacture parameters, reproducible and precise titanium scaffolds were produced. Reconstructed three-dimensional image and sectional structure of the scaffold were examined by micro-computed tomography and relative software. Alkali treatment was carried out on these manufactured porous scaffolds to produce nanoporous hydrophilic film. After 6 days deposition in simulated body fluid (SBF) containing sodium citrate (SC-SBF), plate-like amorphous calcium phosphate (ACP) coating was deposited on scaffold surface. Ultrasonication tests qualitatively indicated an enhanced adhesion force of apatite coatings deposited in SC-SBF compared to that deposited in SBF. And the effect of citrate ions on the CO{sub 3}{sup 2−} incorporation rate in apatite coating was quantitatively examined by bending vibration of CO{sub 3}{sup 2−} at ∼874 cm{sup −1}. Results indicated the highest carbonate content was obtained at the citrate ion concentration of 6 × 10{sup −5} mol/L in SC-SBF. These three-dimensional porous titanium-apatite hybrid scaffolds are expected to find application in bone tissue regeneration.

The oxidation state of sulfur in apatite: A new oxybarometer?

Science.gov (United States)

Fiege, A.; Konecke, B.; Kim, Y.; Simon, A. C.; Becker, U.; Parat, F.

2016-12-01

Oxygen fugacity (fO2) of magmatic and hydrothermal systems influences, for instance, crystallization and degassing processes as well as metal solubilities in melts and fluids. Apatite is a ubiquitous mineral in magmatic and hydrothermal environments that can record and preserve volatile zonation. It can contain several thousand μg/g of the redox sensitive element sulfur (S), making S-in-apatite a potential fO2 sensor. Despite the polyvalent properties of S (e.g., S2-, S4+, S6+), the oxidation state and incorporation mechanisms of S in the apatite structure are poorly understood. In this study, the oxidation state of S-in-apatite as a function of fO2 is investigated using X-ray absorption near-edge structures (XANES) spectroscopy at the S K-edge. Apatites crystallized from lamproitic melts at 1000°C, 300 MPa and over a broad range of fO2 and sulfur fugacities (fS2) were measured. Peaks corresponding to S6+ ( 2482 eV), S4+ ( 2478 eV) and S2- ( 2470 eV) were identified in apatite. The integrated S6+/STotal (STotal = S6+ + S4+ + S2-) peak area ratios show a distinct positive correlation with fO2, increasing from 0.17 at FMQ+0 to 0.96 at FMQ+3. Ab-initio calculations were performed to further understand the energetics and geometry of incorporation of S6+, S4+ and S2- into the apatite (F-, Cl-, OH-) end-members. The results confirm that apatite can contain three different oxidations states of S (S6+, S4+, S2-) as a function of fO2. This makes apatite probably the first geologically relevant mineral to incorporate reduced (S2-), intermediate (S4+), and oxidized (S6+) S in variable proportions. We emphasize that the strong dependence of the S oxidation state in apatite as a function of fO2 is also coupled with changing S content of apatite and co-existing melt (i.e., with changing fS2), resulting in a complex correlation between [1] apatite-melt (or fluid) partitioning, [2] redox conditions and [3] the melt and/or fluid composition, making the application of previously

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

Energy Technology Data Exchange (ETDEWEB)

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.

Polycrystalline apatite synthesized by hydrothermal replacement of calcium carbonates

Science.gov (United States)

Kasioptas, Argyrios; Geisler, Thorsten; Perdikouri, Christina; Trepmann, Claudia; Gussone, Nikolaus; Putnis, Andrew

2011-06-01

Aragonite and calcite single crystals can be readily transformed into polycrystalline hydroxyapatite pseudomorphs by hydrothermal treatment in a (NH 4) 2HPO 4 solution. Scanning electron microscopy of the reaction products showed that the transformation of aragonite to apatite is characterised by the formation of a sharp interface between the two phases and by the development of intracrystalline porosity in the hydroxyapatite phase. In addition, electron backscattered diffraction (EBSD) imaging showed that the c-axis of apatite is predominantly oriented perpendicular to the reaction front with no crystallographic relationship to the aragonite lattice. However, the Ca isotopic composition of the parent aragonite, measured by thermal ionization mass spectrometry was inherited by the apatite product. Hydrothermal experiments conducted with use of phosphate solutions prepared with water enriched in 18O (97%) further revealed that the 18O from the solution is incorporated in the product apatite, as measured by micro-Raman spectroscopy. Monitoring the distribution of 18O with Raman spectroscopy was possible because the incorporation of 18O in the PO 4 group of apatite generates four new Raman bands at 945.8, 932, 919.7 and 908.8 cm -1, in addition to the ν1(PO 4) symmetric stretching band of apatite located at 962 cm -1, which can be assigned to four 18O-bearing PO 4 species. The relative intensities of these bands reflect the 18O content in the PO 4 group of the apatite product. By using equilibrated and non-equilibrated solutions, with respect to the 18O distribution between aqueous phosphate and water, we could show that the concentration of 18O in the apatite product is linked to the degree of 18O equilibration in the solution. The textural and chemical observations are indicative of a coupled mechanism of aragonite dissolution and apatite precipitation taking place at a moving reaction interface.

Influence of agitation intensity on flotation rate of apatite particles

Directory of Open Access Journals (Sweden)

Francisco Gregianin Testa

Full Text Available Abstract The agitation intensity has a directly influence on flotation performance, lifting the particles and promoting the contact of bubbles and particles. In this paper, the energy input by the agitation on apatite flotation was investigated. The influence of pulp agitation in the flotation rate of particles with different sizes and two dosage levels was evaluated by batch testing. The flotation tests were conducted in an oscillating grid flotation cell (OGC, developed to promote a near isotropic turbulence environment. The cell is able to control the intensity of agitation and measure the energy transferred to the pulp phase. A sample of pure apatite was crushed (P80=310µm, characterized and floated with sodium oleate as collector. Four levels of energy dissipation, from 0.1 to 2 kWm-3, and two levels of collector dosage are used during the tests. The flotation kinetics by particle size were determined in function of the energy transferred. The results show a strong influence of the agitation intensity on the apatite flotation rate with both low and high dosage. For fine particles, when increasing the energy input, the flotation rate increase too, and this fact can be attributed to elevation of bubble-particle collisions. The kinetic result for the coarse particles demonstrated a reduction of the flotation rate whenever the energy input for this particle size was increased, whereby the turbulence caused by the agitation promotes the detachment of bubble-particle.

The function of Sn(II)-apatite as a Tc immobilizing agent

Energy Technology Data Exchange (ETDEWEB)

Asmussen, R. Matthew, E-mail: matthew.asmussen@pnnl.gov [Energy and Environment Directorate, Pacific Northwest National Laboratory, 902 Battelle Blvd, Richland, WA, 99352 (United States); Neeway, James J.; Lawter, Amanda R.; Levitskaia, Tatiana G. [Energy and Environment Directorate, Pacific Northwest National Laboratory, 902 Battelle Blvd, Richland, WA, 99352 (United States); Lukens, Wayne W. [Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720 (United States); Qafoku, Nikolla P. [Energy and Environment Directorate, Pacific Northwest National Laboratory, 902 Battelle Blvd, Richland, WA, 99352 (United States)

2016-11-15

At the U.S. Department of Energy Hanford Site, Tc-99 is a component of low-activity waste (LAW) fractions of the nuclear tank waste and removal of Tc from LAW streams would greatly benefit the site remediation process. In this study, we investigated the removal of Tc(VII), as pertechnetate, from deionized water (DIW) and a LAW simulant through batch sorption testing and solid phase characterization using tin (II) apatite (Sn-A) and SnCl{sub 2}. Sn-A showed higher levels of Tc removal from both DIW and LAW simulant. Scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/XEDS) and X-ray absorption spectroscopy (XAS) of reacted Sn-A in DIW showed that TcO4- is reduced to Tc(IV) on the Sn-A surface. The performance of Sn-A in the LAW simulant was lowered due to a combined effect of the high alkalinity, which lead to an increased dissolution of Sn from the Sn-A, and a preference for the reduction of Cr(VI). - Highlights: • Sn(II)-Apatite shows high proficiency in removing Tc(VII) from neutral solutions. • The removal of the Tc(VII) by Sn(II)-apatite is done via reduction to Tc(IV)O{sub 2} × H{sub 2}O. • In LAW Sn(II)-apatite is less efficient in removing Tc(VII). • Interference in LAW due to a preference for the reduction of Cr(VI) and the high pH. • Sn(II)-apatite can remove Tc(VII) from LAW effectively through increasing material added.

Structurally bound sulfide and sulfate in apatite from the Philips Mine iron oxide - apatite deposit, New York, USA: A tracer of redox changes

Science.gov (United States)

Sadove, G.; Konecke, B.; Fiege, A.; Simon, A. C.

2017-12-01

Multiple competing hypotheses attempt to explain the genesis of iron oxide-apatite (IOA) ore deposits. Many studies have investigated the chemistry of apatite because the abundances of F and Cl can distinguish magmatic vs. hydrothermal processes. Recent experiments demonstrate that apatite incorporates S6+, S4+, and S2-, and that total sulfur (∑S) as well as the S6+/∑S ratio in apatite vary systematically as a function of oxygen fugacity [1], providing information about sulfur budget and redox. Here, we present results from X-ray absorption near-edge structure (XANES) spectroscopy at the S K-edge, electron microprobe analyses, cathodoluminescence (CL) imaging, and element mapping of apatite from the Philip's Mine IOA deposit, southern Adirondack Mountains, USA. The Philip's Mine apatite contains inclusions of pyrite and pyrrhotite, where the latter includes iron oxide and Ni-rich domains. The apatite also contains inclusions of monazite, and exhibits complex CL zonation coincident with variations in the abundances of REE and S. The presence of monazite fingerprints fluid-mediated dissolution-reprecipitation of originally REE-enriched apatite [2]. The S XANES spectra reveal varying proportions of structurally bound S6+ and S2-, as the S6+/∑S ratio ranges from sulfide-only to sulfate-only. Notably, sulfide-dominated domains contain higher S contents than sulfate-dominated regions. These observations are consistent with co-crystallization of apatite and monosulfide solid solution (MSS) at reducing conditions, followed by decomposition of MSS to pyrrhotite, pyrite and intermediate solid solution (ISS, which is not preserved; [3]). Metasomatism of that assemblage by an oxidized fluid resulted in formation of monazite in apatite and iron oxide domains in pyrrhotite. We conclude that the deposit formed by a H2S-Fe-rich volatile phase, possibly evolved from a rather primitive magmatic source, which is consistent with the low Ti content of magnetite. The deposit was

Data management implementation plan for the Bear Creek Valley treatability study phase 2 hydraulic performance testing, Oak Ridge Y-12 Plant, Oak Ridge, Tennessee

International Nuclear Information System (INIS)

1997-12-01

The overall objective of the Bear Creek Valley treatability study is to provide site-specific data defining potential treatment 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, the Bear Creek Valley treatability study Phase 2 hydraulic performance testing, directly supports the Bear Creek Valley Feasibility Study. Specific project objectives include (1) installing monitoring and extraction wells, (2) installing a groundwater extraction trench, (3) performing pumping tests of the extraction wells and trench, (4) determining hydraulic gradients, and (5) collecting water quality parameters. The primary purpose of environmental data management is to provide a system for generating and maintaining technically defensible data. To meet current regulatory requirements for the Environmental Restoration Program, complete documentation of the information flow must be established. To do so, each step in the data management process (collection, management, storage, and analysis) must be adequately planned and documented. This document will serve to identify data management procedures, expected data types and flow, and roles and responsibilities for all data management activities associated with this project

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

International Nuclear Information System (INIS)

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

Can Polyphosphate Biochemistry Affect Biological Apatite Saturation?

Science.gov (United States)

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

Immobilization of uranium in contaminated soil by natural apatite addition

International Nuclear Information System (INIS)

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

2007-01-01

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 2 O 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 2 O 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)

Treatability of stabilize landfill leachate by using pressmud ash as an adsorbent

Science.gov (United States)

Azme, N. N. Mohd; Murshed, M. F.

2018-04-01

Leachate is a liquid produced from the landfill that contains high concentration of heavy metals, chemicals and nutrient loading. The treatability of these contaminants are complicated since the current treatment technology are costly and site specific. Therefore, this study was conducted to evaluate the treatability of stabilized landfill leachate by using waste (pressmud ash) as an absorbent. Pressmud ash was prepared by burning at different temperature from 100 to 700 degree Celsius and test at 24 hours shaking time, pH 8, and 4000 rpm. Leachate samples were collected from municipal solid waste (MSW) Pulau Burung Sanitary Landfill (PBSL) and were analyzed for heavy metal, COD, ammonia and colour. This study was performed in two phases i) leachate characteristic, ii) treatability assessment by using pressmud ash. Pressmud was sampled from the sugar mill, Malaysian Sugar Manufacturing (MSM) Sdn Bhd, Seberang Perai, Pulau Pinang. The pressmud with 400°C are highly potential material with a low cost which can be a good adsorbent was capable reducing efficiencies of COD (60.76%), ammonia (64.37%) and colour (35.78%) from real wastewater leachate. Pressmud showed good sorption capability. Surface modification with burning greatly enhanced the reducing efficiency of sugar waste based adsorbent with adsorption efficiency.

Sampling and analysis plan for phase II of the Bear Creek Valley treatability study Oak Ridge Y-12 Plant, Oak Ridge, Tennessee

International Nuclear Information System (INIS)

1997-05-01

The Bear Creek Valley (BCV) Treatability Study is intended to provide site-specific data defining potential treatment technologies applicable to contaminated groundwater and surface water. This project directly supports Alternative 5 of the base action in the BCV Feasibility Study, and indirectly supports other alternatives through proof of concept. In that role, the ultimate goal is to install a treatment system that will remove uranium and nitrate from groundwater before it reaches Bear Creek. A secondary goal is the concurrent removal of technetium and several metals that impact ecological risk. This project is intended to produce hydraulic and treatment performance data required to design the treatment system to reach those goals. This project will also generate information that can be applied at other facilities within the Oak Ridge Reservation. This report is the sampling and analysis plan (SAP) for the field work component of Phase II of the BCV Treatability Study. Field work for this phase of the BCV Treatability Study consists of media testing. In-field continuous flow tests will be conducted over an extended time period (5 weeks) to generate data on long-term treatment effects on potential treatment media including sorbents and zero valent iron, over 28 weeks for constructed wetlands treatment, and over 24 weeks for algal mats treatment. The SAP addresses environmental sampling at the S-3 Site at the Oak Ridge Y-12 Plant. Samples will be taken from groundwater, effluent from test columns, effluent from an algal mat reactor, and effluent from a pilot-scale wetlands. This plan will be implemented as part of the BCV Phase II Treatability Study Best Management Practices Plan and in conjunction with the BCV Phase II Treatability Study Health and Safety Plan and the BCV Phase II Treatability Study Waste Management Plan

Apatite mineralization in elasmobranch skeletons via a polyphosphate intermediate

Science.gov (United States)

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

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

Energy Technology Data Exchange (ETDEWEB)

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.

Bioceramics of apatites: an option for bone regeneration

International Nuclear Information System (INIS)

Arxer, Eliana Alves; Almeida Filho, Edson de; Guastaldi, Antonio Carlos

2011-01-01

The bioceramics of calcium phosphate called apatite, are widely used as material for bone replacement and regeneration, due to its similarity to the mineral component of bones and teeth. The apatites are biocompatible, bioactive and integrate with living tissue by the same active process of physiological bone remodeling. These bioceramics may be used in medical, dental and orthopedic applications. In this research, it was used the wet method for the synthesis of the powder and biomimetic method for coating the surface. The Solubility study was performed in the layer deposited, apatite, for possible application as a platform for inorganic drug delivery. The bioceramics were characterized by MEV, DRX, and EDS. The curves of solubility of apatite in coatings showed that the OCP phase had a higher rate of release in the short term (4 days) while the HA phase showed a gradual release throughout the experiment (16 days). (author)

Study of the auto-irradiation effects in apatites structure materials

International Nuclear Information System (INIS)

Soulet, St.

2000-11-01

The incorporation of an actinide in a material puts it to the action of an alpha particle, of some MeV always followed by the recoil of the residual nucleus. This last ones, with an energy of about a hundred of keV produces the greatest part of the irradiation damages. The study of the natural analogues has allowed to identify the fluoro-apatites which have a high amount of phosphates groups, as potential actinides conditioning matrices. Former works, simulating the alpha decay in the monocrystalline phospho-calcic fluoro-apatite have revealed an exfoliation phenomenon and an annealing of the defects which are formed by the recoil nuclei by the helium ions. This work has shown that the exfoliation can not be produced on polycrystalline apatitic materials (phospho-calcic fluoro-apatite and fluoro-apatite with one silicate) probably on account of the removal of helium outside the grains and by the diffusion of helium inside the grain boundaries. On the other hand, these helium removal ways decrease the chemical resistance of the fluoro-apatite. In the same way, the dissolution velocity of the apatite is strongly increased above the damage threshold corresponding to the percolation of the isolated defects and especially in the case of total amorphization. Concerning the effect of the recoil and annealing nuclei by the alpha particles, an original study method including the use of a transmission electron microscope coupled with a ions implanter has been carried out. This device has allowed to make irradiations simulating the alpha decay and to follow in situ the evolution of polycrystalline samples disorder. It has been shown that for all the solid solution of phospho-silicated fluoro-apatites, the amorphization is produced directly in series. In the same way, on account of this technique, the efficiency of the annealing by alpha has been measured on different apatite compositions. The main result shows that the efficiency of the annealing by alpha in the fluoro-apatite

Survey of commercial firms with mixed-waste treatability study capability

International Nuclear Information System (INIS)

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

1996-01-01

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 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

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

Energy Technology Data Exchange (ETDEWEB)

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

Study on apatite compounds; Apataitokei kagobutsu ni kansuru kenkyu

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-11-28

To clarify the material properties of apatite compounds, the synthesis method, and the evaluation of physical properties of material and elementary technology were investigated. For the study on synthesis and crystal growth, a method of precipitating calcium phosphate on the surface of metal was investigated by means of relatively mild electrolytic method using liquid phase system. A new molding method of Ca defective apatite was established. Composite similar to vital bone was prepared by means of a new low-temperature sintering. For the study on chemical properties, from the model experiments, it was found that the self-organizing phenomenon, which is observed in the composite of apatite and collagen, happened between the organic single molecular film and crystal of apatite. For the study on evaluation of physical properties and elementary technology, the surface and interface of ceramics such as apatite were investigated by means of spectroscopy, the electronic state was analyzed by the quantum chemical calculation, and the crystalline structure was analyzed using X-ray equipment. 270 refs., 102 figs., 10 tabs.

Joint refinery selenium treatability study

International Nuclear Information System (INIS)

Meyer, C.L.; Folwarkow, S.

1993-01-01

The San Francisco Regional Water Quality Control Board recently established mass limits on discharges of selenium to the San Francisco Bay from several petroleum refineries. The refineries had been working independently to develop control strategies, including both source control and treatment options, for removal of selenium from their discharges. By January 1992, over fifty different combinations of treatment technologies, wastewater streams, and pretreatment steps had been investigated to determine their effectiveness and feasibility as selenium removal processes. No treatment process studied could achieve the required mass limits without serious negative environmental consequences, such as generation of large amounts of hazardous sludge. To better facilitate the development of a feasible selenium treatment process, the six Bay Area refineries shared results of their studies and identified several technologies that, with further work, could be developed further. This additional work is currently being carried out as part of a joint selenium treatability study sponsored by the Western States Petroleum Association. A review of the previous source control and treatment studies, along with a description of the current treatability studies will be discussed

DOE Waste Treatability Group Guidance

International Nuclear Information System (INIS)

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

DOE Waste Treatability Group Guidance

Energy Technology Data Exchange (ETDEWEB)

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.

300 Area Treatability Test: Laboratory Development of Polyphosphate Remediation Technology for In Situ Treatment of Uranium Contamination in the Vadose Zone and Capillary Fringe

Energy Technology Data Exchange (ETDEWEB)

Wellman, Dawn M.; Pierce, Eric M.; Bacon, Diana H.; Oostrom, Martinus; Gunderson, Katie M.; Webb, Samuel M.; Bovaird, Chase C.; Cordova, Elsa A.; Clayton, Eric T.; Parker, Kent E.; Ermi, Ruby M.; Baum, Steven R.; Vermeul, Vincent R.; Fruchter, Jonathan S.

2008-09-30

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 stabilize uranium within the 300 Area vadose and smear zones of the Hanford Site. The general treatability testing approach consisted of conducting studies with site sediment and under site conditions, to develop an effective chemical formulation and infiltration approach for the polyphosphate amendment under site conditions. Laboratory-scale dynamic column tests were used to 1) quantify the retardation of polyphosphate and its degradation products as a function of water content, 2) determine the rate of polyphosphate degradation under unsaturated conditions, 3) develop an understanding of the mechanism of autunite formation via the reaction of solid phase calcite-bound uranium and aqueous polyphosphate remediation technology, 4) develop an understanding of the transformation mechanism, the identity of secondary phases, and the kinetics of the reaction between uranyl-carbonate and -silicate minerals with the polyphosphate remedy under solubility-limiting conditions, and 5) quantify the extent and rate of uranium released and immobilized based on the infiltration rate of the polyphosphate remedy and the effect of and periodic wet-dry cycling on the efficacy of polyphosphate remediation for uranium in the vadose zone and smear zone.

UV photofunctionalization promotes nano-biomimetic apatite deposition on titanium

Directory of Open Access Journals (Sweden)

Saita M

2016-01-01

Full Text Available Makiko Saita,1 Takayuki Ikeda,1,2 Masahiro Yamada,1,3 Katsuhiko Kimoto,4 Masaichi Chang-Il Lee,5 Takahiro Ogawa1 1Division of Advanced Prosthodontics, Weintraub Center for Reconstructive Biotechnology, UCLA School of Dentistry, Los Angeles, CA, USA; 2Department of Complete Denture Prosthodontics, Nihon University School of Dentistry, Yokosuka, Japan; 3Division of Molecular and Regenerative Prosthodontics, Tohoku University Graduate School of Dentistry, Sendai, Miyagi, Japan; 4Department of Prosthodontics and Oral Rehabilitation, 5Yokosuka-Shonan Disaster Health Emergency Research Center and ESR Laboratories, Kanagawa Dental University Graduate School of Dentistry, Yokosuka, Japan 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

Determination of palaeotemperatures of apatite with the fission-track method

International Nuclear Information System (INIS)

Bertagnolli, E.; Maerk, E.; Bertel, E.; Pahl, M.; Maerk, T.D.

1981-01-01

As a consequence of thermal fading of fission tracks in minerals, the fission-track dating method can be used to obtain a sensitive geothermometer for unfolding thermal events in the history of rocks, especially if it is possible to determine the temperature associated with a measured fission-track age, i.e., yielding a temperature age. Based on the concept of a minimum fission-track length the differential annealing equation has been solved for apatite, taking into account the fact that the annealing coefficient depends also on the degree of fission-track reduction. This allows us to calculate an improved age-temperature relationship for apatite, which gives for a measured corrected fission-track age the corresponding temperature, assuming either linear or exponential time-dependence of the temperature. The present results for apatite are compared with previous calculations in apatite and sphene. As expected, a fission-track age of apatite dates a younger (lower temperature) point in the thermal-cooling history than a fission-track age of sphene. (author)

Apatite-mediated actin dynamics in resorbing osteoclasts.

Science.gov (United States)

Saltel, Frédéric; Destaing, Olivier; Bard, Frédéric; Eichert, Diane; Jurdic, Pierre

2004-12-01

The actin cytoskeleton is essential for osteoclasts main function, bone resorption. Two different organizations of actin have been described in osteoclasts, the podosomes belt corresponding to numerous F-actin columns arranged at the cell periphery, and the sealing zone defined as a unique large band of actin. To compare the role of these two different actin organizations, we imaged osteoclasts on various substrata: glass, dentin, and apatite. Using primary osteoclasts expressing GFP-actin, we found that podosome belts and sealing zones, both very dynamic actin structures, were present in mature osteoclasts; podosome belts were observed only in spread osteoclasts adhering onto glass, whereas sealing zone were seen in apico-basal polarized osteoclasts adherent on mineralized matrix. Dynamic observations of several resorption cycles of osteoclasts seeded on apatite revealed that 1) podosomes do not fuse together to form the sealing zone; 2) osteoclasts alternate successive stationary polarized resorption phases with a sealing zone and migration, nonresorption phases without any specific actin structure; and 3) apatite itself promotes sealing zone formation though c-src and Rho signaling. Finally, our work suggests that apatite-mediated sealing zone formation is dependent on both c-src and Rho whereas apico-basal polarization requires only Rho.

An evaluation by midwives and gynecologists of treatability of cervical lesions by cryotherapy among human papillomavirus-positive women.

Science.gov (United States)

Gage, Julia C; Rodriguez, Ana Cecilia; Schiffman, Mark; Adadevoh, Sydney; Larraondo, Manuel J Alvarez; Chumworathayi, Bandit; Lejarza, Sandra Vargas; Araya, Luis Villegas; Garcia, Francisco; Budihas, Scott R; Long, Rodney; Katki, Hormuzd A; Herrero, Rolando; Burk, Robert D; Jeronimo, Jose

2009-05-01

To estimate efficacy of a visual triage of human papillomavirus (HPV)-positive women to either immediate cryotherapy or referral if not treatable (eg, invasive cancer, large precancers). We evaluated visual triage in the HPV-positive women aged 25 to 55 years from the 10,000-woman Guanacaste Cohort Study (n = 552). Twelve Peruvian midwives and 5 international gynecologists assessed treatability by cryotherapy using digitized high-resolution cervical images taken at enrollment. The reference standard of treatability was determined by 2 lead gynecologists from the entire 7-year follow-up of the women. Women diagnosed with histologic cervical intraepithelial neoplasia grade 2 or worse or 5-year persistence of carcinogenic HPV infection were defined as needing treatment. Midwives and gynecologists judged 30.8% and 41.2% of women not treatable by cryotherapy, respectively (P cryotherapy. The proportion of women judged not treatable by a reviewer varied widely and ranged from 18.6% to 61.1%. Interrater agreement was poor with mean pairwise overall agreement of 71.4% and 66.3% and kappa's of 0.33 and 0.30 for midwives and gynecologists, respectively. In future "screen-and-treat" cervical cancer prevention programs using HPV testing and cryotherapy, practitioners will visually triage HPV-positive women. The suboptimal performance of visual triage suggests that screen-and-treat programs using cryotherapy might be insufficient for treating precancerous lesions. Improved, low-technology triage methods and/or improved safe and low-technology treatment options are needed.

Effects of Metal Ions on the Flotation of Apatite, Dolomite and Quartz

Directory of Open Access Journals (Sweden)

Yaoyang Ruan

2018-04-01

Full Text Available The effects of Ca2+, Mg2+, Al3+, and Fe3+ on the flotation behaviors of apatite, dolomite and quartz were investigated through a micro-flotation test, and the influence of calcium ions on the flotation of these minerals was further elucidated by solution chemistry study, zeta potential measurement, and X-ray photoelectron spectroscopy (XPS analyses. The results indicate that an appropriate amount of Ca2+ and Mg2+ can improve the floatability of apatite but had a negligible effect on the flotation performance of dolomite, whereas Al3+, Fe3+, and excessive amounts of Ca2+ decreased the recovery of apatite and dolomite. The studied metal cations can activate quartz at a particular pH. It can be inferred from solution chemistry and zeta potential measurement that the influence of metal ions on the flotation of different minerals should be attributed to the adsorption of various hydrolysis species on the mineral surfaces. XPS analyses reveal that calcium ions can enhance the adsorption of anionic collector on apatite and quartz surfaces, and there are no apparent changes to be observed on the surface of dolomite in the absence and presence of calcium ions at a concentration of 2.5 × 10−3 M, which was in good agreement with the micro-flotation results.

Mineralogical and geochemical studies on apatites and phosphate host rocks of Esfordi deposit, Yazd province, to determine the origin and geological setting of the apatite

Directory of Open Access Journals (Sweden)

Mohammad Ali Rajabzadeh

2014-10-01

Full Text Available Introduction Iron-apatite ore deposits well known as Kiruna iron type formed in association with calc-alkaline volcanism from Proterozoic to Tertiary (Hitzman et al., 1992. Liquid immiscibility in an igneous system was proposed to explain the formation of the iron oxides accompanying apatite in mineralized zones (Förster and Jafarzadeh, 1994; Daliran, 1999. The mode of ore formation however, is a matter in debate. Bafq region in Central Iran is one of the greatest iron mining regions in Iran with 750 million tons of reservoir. The majority of the iron deposits contains apatite as minor mineral and underwent metamorphism-alteration in varying degrees. The mode of formation and geological setting of Esfordi iron-apatite deposit in this region with an average of 13.9 wt% apatite are discussed using geochemical and mineralogical data along with field description. Materials and methods Fifty-three samples of mineralized zones and host rocks collected from 7 cross sections were studied by conventional microscopic methods. Seven representative samples were determined by XRD at Department of Physics, Shiraz University. Fifteen and six samples were also analyzed for major and trace elements using XRF at Binaloud Co. Iran, and ICP-MS at Labwest Minerals Analysis, Australia, respectively. Microprobe analyses were carried out on apatite in Geo Forschungs Zentrum Telegrafenberg at Potsdam University, Germany. Results Field observation shows that igneous host rocks in Esfordi were intensively altered by hydrothermal fluids. The ores are surrounded by wide altered halos. Petrographic investigation indicated that the most important alterations are of potassic, carbonatitic and silicification types. Magnetite and apatite occur as major minerals, accompanied by minor hematite and goethite in the mineralized zones. Rare Earth Element (REE minerals are present as minor phases in the ores. Three apatite mineralization types (vein, massive, and disseminated were

Tooth apatite as a bone substitute: an experimental study and clinical applications

International Nuclear Information System (INIS)

Eun-Seok Kim; Pill-Hoon Choung

1999-01-01

The purpose of this study is to evaluate the usefulness of calcined teeth powder as biological apatite. The animal experiment was performed in 36 rabbits aging 6 weeks and weighing 1.6 kg. In experimental group, tooth apatite powder was implanted to 10 mm bony defects in diameter made on the cranial bone of the rabbits. As control groups, synthetic porous hydroxyapatite and resorbable type calcium carbonate were implanted to the defects of same size. Each group was sacrificed in 1, 2, 4, 6, 8, 12 weeks after the surgery. Specimens were prepared for decalcified samples and observed by a light microscope. And we also performed quantitative analysis of new bone formation through image analysis using computer. In clinical applications, we used tooth apatite alone or mixed with decalcified freeze-dried bone for reconstruction of bony defects in 15 patients undergone enucleation of cyst or ameloblastoma. The obtained results were as follows; 1) The powder of the calcined teeth was called as 'tooth apatite' and it seemed to have biocompatibility in rabbits and human. 2) In group of tooth apatite, after 4 weeks of operation, new bone directly bonded to the particles was observed. And in 12 weeks of it, new bone occupied most of the bony defects. In 6 weeks, resorption of the tooth apatite particles was observed. Thus the tooth apatite was regarded as one of resorbable apatite. 3) The group of tooth apatite showed new bone formation similar to the group of porous hydroxyapatite, but they were inferior to the group of resorbable calcium carbonate. 4) In clinical application, tooth apatite had biocompatibility and new bone formation was observed without any complication except for 1 case. So we think it is a useful bone substitute with osteoconductivity

Effect of radiation damage on the infrared properties of apatite

International Nuclear Information System (INIS)

Anis Faridah Md Nori; Yusof Mohd Amin; Rosli Mahat; Burhanuddin Kamaluddin

1991-01-01

Apatites are known to contain radioactive elements such as uranium and thorium at a few ppm in concentration. These elements decay and produce fission tracks inside the crystals. The presence of such tracks have been known to affect the thermoluminescence (TL) properties of apatites. These fission tracks can be removed by annealing the crystals in air. In this paper we present the result of a preliminary study on the effect of radiation damage on the infrared transmission of apatites

Pyrophosphate-Inhibition of Apatite Formation Studied by In Situ X-Ray Diffraction

Directory of Open Access Journals (Sweden)

Casper Jon Steenberg Ibsen

2018-02-01

Full Text Available The pathways to crystals are still under debate, especially for materials relevant to biomineralization, such as calcium phosphate apatite known from bone and teeth. Pyrophosphate is widely used in biology to control apatite formation since it is a potent inhibitor of apatite crystallization. The impacts of pyrophosphate on apatite formation and crystallization kinetics are, however, not fully understood. Therefore, we studied apatite crystallization in water by synchrotron in situ X-ray diffraction. Crystallization was conducted from calcium chloride (0.2 M and sodium phosphate (0.12 M at pH 12 where hydrogen phosphate is the dominant phosphate species and at 60 °C to allow the synchrotron measurements to be conducted in a timely fashion. Following the formation of an initial amorphous phase, needle shaped crystals formed that had an octacalcium phosphate-like composition, but were too small to display the full 3D periodic structure of octacalcium phosphate. At later growth stages the crystals became apatitic, as revealed by changes in the lattice constant and calcium content. Pyrophosphate strongly inhibited nucleation of apatite and increased the onset of crystallization from minute to hour time scales. Pyrophosphate also reduced the rate of growth. Furthermore, when the pyrophosphate concentration exceeded ~1% of the calcium concentration, the resultant crystals had reduced size anisotropy suggesting that pyrophosphate interacts in a site-specific manner with the formation of apatite crystals.

Rare earth elements materials production from apatite ores

International Nuclear Information System (INIS)

Anufrieva, A V; Buynovskiy, A S; Makaseev, Y N; Mazov, I N; Nefedov, R A; Sachkov, V I; Valkov, A V; Andrienko, O S; Stepanova, O B

2016-01-01

The paper deals with the study of processing apatite ores with nitric acid and extraction of the rare earth elements. The rare earth elements can be successfully separated and recovered by extraction from the nitrate- phosphate solution, being an tributyl phosphate as extraction agent. The developed scheme of the processing apatite concentrate provides obtaining rare earth concentrates with high qualitative characteristics. (paper)

An Evaluation by Midwives and Gynecologists of Treatability of Cervical Lesions by Cryotherapy Among Human Papillomavirus–Positive Women

Science.gov (United States)

Gage, Julia C.; Rodriguez, Ana Cecilia; Schiffman, Mark; Adadevoh, Sydney; Alvarez Larraondo, Manuel J.; Chumworathayi, Bandit; Lejarza, Sandra Vargas; Araya, Luis Villegas; Garcia, Francisco; Budihas, Scott R.; Long, Rodney; Katki, Hormuzd A.; Herrero, Rolando; Burk, Robert D.; Jeronimo, Jose

2010-01-01

Objectives To estimate efficacy of a visual triage of human papillomavirus (HPV)– positive women to either immediate cryotherapy or referral if not treatable (eg, invasive cancer, large precancers). Methods We evaluated visual triage in the HPV-positive women aged 25 to 55 years from the 10,000-woman Guanacaste Cohort Study (n = 552). Twelve Peruvian midwives and 5 international gynecologists assessed treatability by cryotherapy using digitized high-resolution cervical images taken at enrollment. The reference standard of treatability was determined by 2 lead gynecologists from the entire 7-year follow-up of the women. Women diagnosed with histologic cervical intraepithelial neoplasia grade 2 or worse or 5-year persistence of carcinogenic HPV infection were defined as needing treatment. Results Midwives and gynecologists judged 30.8% and 41.2% of women not treatable by cryotherapy, respectively (P cryotherapy. The proportion of women judged not treatable by a reviewer varied widely and ranged from 18.6%to 61.1%. Interrater agreement was poor with mean pairwise overall agreement of 71.4% and 66.3% and κ ’s of 0.33 and 0.30 for midwives and gynecologists, respectively. Conclusions In future “screen-and-treat” cervical cancer prevention programs using HPV testing and cryotherapy, practitioners will visually triage HPV-positive women. The suboptimal performance of visual triage suggests that screen-and-treat programs using cryotherapy might be insufficient for treating precancerous lesions. Improved, low-technology triage methods and/or improved safe and low-technology treatment options are needed. PMID:19509579

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

Science.gov (United States)

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.

Understanding the evolution of S- and I-type granitic plutons through analysis of apatite.

Science.gov (United States)

Hess, B. L.; Fiege, A.; Tailby, N.

2017-12-01

The major and trace element composition of apatites from the Lachlan fold belt (LFB) S- and I-type granitoids (Australia) and the Central French Massif (CFM) S-type leucogranites (France) were analyzed to investigate their compositional and redox variation. Apatite is a common accessory mineral in magmatic systems that can incorporate a variety of trace elements, including the polyvalent elements sulfur (S), iron (Fe), and manganese (Mn). It was recently discovered that apatite can incorporate three oxidation states of S (S6+, S4+, S2-) into its structure as a function of oxygen fugacity [1]. However, the oxidation states of Mn and Fe in apatite are essentially unknown (2+ and/or 3+). In this study, we collected many electron probe line transects across apatites in several different host phases from a variety of S- and I-type plutons. The F-H-Cl contents of the S- and I-type LFB samples were similar ( 2.9 wt% F, 0.4 wt% Cl, 0.5 wt% OH). The CFM S-types contained virtually no Cl and ranged from near-endmember OH-apatite to near-endmember F-apatite. The apatites of all studied the S- and I-type plutons are characterized by similar ranges of Fe content (X-ray absorption near-edge structure (XANES) spectroscopy. The spectra show variability in S oxidation states ranging from mostly sulfate down to nearly equal S6+/S2- ratios, indicating redox variations during apatite formation. The S-type Mn + Fe content plots in a 1:1 ratio against calcium (Ca) in atoms per formula unit, while the I-type apatites have too low Mn and Fe to show a clear trend. Thus, divalent Mn and Fe probably replace Ca2+ in the S-types' apatite structure, while the incorporation of trivalent Mn or Fe in apatite is rather unlikely. We suggest that Mn and Fe contents in apatite may become a useful tracer of melt evolution once the distributions coefficients are experimentally calibrated. [1] Konecke et al. (2017), Am Mineral

Developing biogeochemical tracers of apatite weathering by ectomycorrhizal fungi

Science.gov (United States)

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

Phosphate-induced metal stabilization: Use of apatite and bone char for the removal of soluble radionuclides in authentic and simulated DOE groundwater

International Nuclear Information System (INIS)

Bostick, W.D.; Jarabek, R.J.; Conca, J.L.

1999-01-01

The apatite group of minerals is a family of calcium phosphate phases. Apatite is the principal component of bone tissue, and it also occurs naturally as mineral deposits in the geosphere. Bone char is calcined (coked) animal bone, containing activated carbon as well as calcium phosphate mineral phases. Apatite IItrademark is a more reactive form of apatite, supplied by UFA Ventures, Inc., at a cost of approximately 1/4 that of commercial bone char. Apatite is shown to be effective for the removal of select heavy metal impurities in groundwater. Previous investigations have demonstrated that apatite is an effective medium for the stabilization of soluble lead, cadmium, and zinc from mine waste leachate by the formation of highly insoluble precipitate phases. The performance of bone char and apatite II are compared with other candidate sorption media (including granular activated carbon and anion exchange resin) for the removal of soluble uranyl ion in synthetic DOE Site groundwater supplemented with varying levels of interfering nitrate ion. Apatite II has a greater affinity for U(VI), especially in the presence of nitrate ion, as evidenced by a larger value for the conditional distribution coefficient (Kd) in batch test experiments. Contact of uranyl nitrate solution with apatite II is shown to produce highly insoluble mineral phases of the autunite group (calcium uranyl phosphate hydrates). Apatite II is also demonstrated to be moderately effective for the removal of soluble radioactive isotopes of strontium, but not cesium, when these ions are supplemented into authentic DOE Site groundwater

Lead Speciation and Bioavailability in Apatite-Amended Sediments

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Kirk G. Scheckel

2011-01-01

Full Text Available The in situ sequestration of lead (Pb in sediment with a phosphate amendment was investigated by Pb speciation and bioavailability. Sediment Pb in preamendment samples was identified as galena (PbS with trace amounts of absorbed Pb. Sediment exposed to atmospheric conditions underwent conversion to hydrocerussite and anglesite. Sediments mixed with apatite exhibited limited conversion to pyromorphite, the hypothesized end product. Conversion of PbS to pyromorphite is inhibited under reducing conditions, and pyromorphite formation appears limited to reaction with pore water Pb and PbS oxidation products. Porewater Pb values were decreased by 94% or more when sediment was amended with apatite. The acute toxicity of the sediment Pb was evaluated with Hyalella azteca and bioaccumulation of Pb with Lumbriculus variegatus. The growth of H. azteca may be mildly inhibited in contaminated sediment, with apatite-amended sediments exhibiting on average a higher growth weight by approximately 20%. The bioaccumulation of Pb in L. variegatus tissue decreased with increased phosphate loading in contaminated sediment. The study indicates limited effectiveness of apatite in sequestering Pb if present as PbS under reducing conditions, but sequestration of porewater Pb and stabilization of near-surface sediment may be a feasible and alternative approach to decreasing potential toxicity of Pb.

Radiation damage studies of mineral apatite, using fission tracks and thermoluminescence techniques

International Nuclear Information System (INIS)

Al-Khalifa, I.J.M.

1988-01-01

In a uranium (/thorium)-rich mineral sample which has not suffered a recent geological high-temperature excursion, the fossil fission track density (FFTD) will give a good indication of its natural radiation damage, provided that its U/Th ratio is known. From our studies of FFTD and thermoluminescence (TL) properties of several samples of apatite from different locations, and containing varying degrees of natural-radiation damage, an anti-correlation is observed between FFTD and TL sensitivity. It is also found that an anti-correlation exists between TL sensitivity and the amount of damage produced artificially by bombarding apatite crystals with different fluences of ∼30 MeV α-particles from a cyclotron. These results indicate that the presence of radiation damage in this mineral (viz., fluorapatite) can severely affect its TL sensitivity (i.e. TL output per unit test dose). The effect of crystal composition on the thermoluminescence and fission track annealing properties of mineral apatite is also reported. We have found that fission track annealing sensitivity and TL sensitivity are both significantly lower in samples of chlorapatite than in samples consisting predominantly of fluorapatite. (author)

Pad A treatability study long-range project plan

International Nuclear Information System (INIS)

Mousseau, J.D.

1991-06-01

This plan addresses the work to be accomplished by the Pad A Treatability Study Project. The purpose of this project is to investigate potential treatment and separation technologies, identify the best technologies, and to demonstrate by both lab- and pilot-scale demonstration, the most applicable remedial technologies for treating plutonium-contaminated salts at the Pad A site located at the Subsurface Disposal Area (SDA) at the Radioactive Waste Management Complex (RWMC) a the Idaho National Engineering Laboratory (INEL). The conduct of this project will be supported by other DOE laboratories, universities, and private industries, who will provide support for near-term demonstrations of treatment and separation technologies. The purpose of this long-range planning document is to present the detailed plan for the implementation of the Pad A Treatability Study Project

Biomimetic nanocrystalline apatite coatings synthesized by Matrix Assisted Pulsed Laser Evaporation for medical applications

Energy Technology Data Exchange (ETDEWEB)

Visan, A. [National Institute for Lasers, Plasma, and Radiation Physics, 409 Atomistilor Street, RO-77125, MG-36, Magurele-Ilfov (Romania); Grossin, D. [CIRIMAT – Carnot Institute, University of Toulouse, ENSIACET, 4 Allée Emile Monso, 31030 Toulouse Cedex 4 (France); Stefan, N.; Duta, L.; Miroiu, F.M. [National Institute for Lasers, Plasma, and Radiation Physics, 409 Atomistilor Street, RO-77125, MG-36, Magurele-Ilfov (Romania); Stan, G.E. [National Institute of Materials Physics, RO-077125, Magurele-Ilfov (Romania); Sopronyi, M.; Luculescu, C. [National Institute for Lasers, Plasma, and Radiation Physics, 409 Atomistilor Street, RO-77125, MG-36, Magurele-Ilfov (Romania); Freche, M.; Marsan, O.; Charvilat, C. [CIRIMAT – Carnot Institute, University of Toulouse, ENSIACET, 4 Allée Emile Monso, 31030 Toulouse Cedex 4 (France); Ciuca, S. [Politehnica University of Bucharest, Faculty of Materials Science and Engineering, Bucharest (Romania); Mihailescu, I.N., E-mail: ion.mihailescu@inflpr.ro [National Institute for Lasers, Plasma, and Radiation Physics, 409 Atomistilor Street, RO-77125, MG-36, Magurele-Ilfov (Romania)

2014-02-15

Highlights: • We report the deposition by MAPLE of biomimetic apatite coatings on Ti substrates. • This is the first report of MAPLE deposition of hydrated biomimetic apatite films. • Biomimetic apatite powder was synthesized by double decomposition process. • Non-apatitic environments, of high surface reactivity, are preserved post-deposition. • We got the MAPLE complete transfer as thin film of a hydrated, delicate material. -- Abstract: We report the deposition by Matrix Assisted Pulsed Laser Evaporation (MAPLE) technique of biomimetic nanocrystalline apatite coatings on titanium substrates, with potential application in tissue engineering. The targets were prepared from metastable, nanometric, poorly crystalline apatite powders, analogous to mineral bone, synthesized through a biomimetic approach by double decomposition process. For the deposition of thin films, a KrF* excimer laser source was used (λ = 248 nm, τ{sub FWHM} ≤ 25 ns). The analyses revealed the existence, in synthesized powders, of labile non-apatitic mineral ions, associated with the formation of a hydrated layer at the surface of the nanocrystals. The thin film analyses showed that the structural and chemical nature of the nanocrystalline apatite was prevalently preserved. The perpetuation of the non-apatitic environments was also observed. The study indicated that MAPLE is a suitable technique for the congruent transfer of a delicate material, such as the biomimetic hydrated nanohydroxyapatite.

Biomimetic nanocrystalline apatite coatings synthesized by Matrix Assisted Pulsed Laser Evaporation for medical applications

International Nuclear Information System (INIS)

Visan, A.; Grossin, D.; Stefan, N.; Duta, L.; Miroiu, F.M.; Stan, G.E.; Sopronyi, M.; Luculescu, C.; Freche, M.; Marsan, O.; Charvilat, C.; Ciuca, S.; Mihailescu, I.N.

2014-01-01

Highlights: • We report the deposition by MAPLE of biomimetic apatite coatings on Ti substrates. • This is the first report of MAPLE deposition of hydrated biomimetic apatite films. • Biomimetic apatite powder was synthesized by double decomposition process. • Non-apatitic environments, of high surface reactivity, are preserved post-deposition. • We got the MAPLE complete transfer as thin film of a hydrated, delicate material. -- Abstract: We report the deposition by Matrix Assisted Pulsed Laser Evaporation (MAPLE) technique of biomimetic nanocrystalline apatite coatings on titanium substrates, with potential application in tissue engineering. The targets were prepared from metastable, nanometric, poorly crystalline apatite powders, analogous to mineral bone, synthesized through a biomimetic approach by double decomposition process. For the deposition of thin films, a KrF* excimer laser source was used (λ = 248 nm, τ FWHM ≤ 25 ns). The analyses revealed the existence, in synthesized powders, of labile non-apatitic mineral ions, associated with the formation of a hydrated layer at the surface of the nanocrystals. The thin film analyses showed that the structural and chemical nature of the nanocrystalline apatite was prevalently preserved. The perpetuation of the non-apatitic environments was also observed. The study indicated that MAPLE is a suitable technique for the congruent transfer of a delicate material, such as the biomimetic hydrated nanohydroxyapatite

Certain distribution characteristics of uranium and thorium in apatite-carbonate ores

Energy Technology Data Exchange (ETDEWEB)

Kharitonova, R Sh; Faizullin, R N; Kozlov, E N; Berman, I B

1979-01-01

A study of the total radioactivity, uranium content, thorium content, U/Th ratio, and the spatial distribution of uranium by the f-radiographic method has demonstrated that the apatite ores of the deposit contain elevated concentrations of radioactive elements that are essentially of thorium origin. The main concentration of uranium and thorium is in the cinnemon-brown apatite. Elevated uranium concentrations are also found in hematite and accessory minerals (monacite, zirconium, titanite). Dolomite, quartz, martite, and second generation apatite were found to be weakly radioactive. The uranium and thorium concentration is correlated to the concentration of phosphorus and other petrogenic elements. An analysis of uranium, thorium, and Th/U distribution indicates that the concentration of radioactive elements is not caused by their primary content in carbonate rock but by the outside introduction of these elements together with phosphorus. The cited analyses confirm the chemogenic-sedimentary origin of the dolomite substrate and the metamorphogenic hydrothermal genesis of apatite mineralization. The data on radioactivity may be used as a reliable exploratory criterion for apatite potential. 3 references, 3 figures.

Amelogenin as a promoter of nucleation and crystal growth of apatite

Science.gov (United States)

Uskoković, Vuk; Li, Wu; Habelitz, Stefan

2011-02-01

Human dental enamel forms over a period of 2-4 years by substituting the enamel matrix, a protein gel mostly composed of a single protein, amelogenin with fibrous apatite nanocrystals. Self-assembly of amelogenin and the products of its selective proteolytic digestion are presumed to direct the growth of apatite fibers and their organization into bundles that eventually comprise the mature enamel, the hardest tissue in the mammalian body. This work aimed to establish the physicochemical and biochemical conditions for the growth of apatite crystals under the control of a recombinant amelogenin matrix (rH174) in combination with a programmable titration system. The growth of apatite substrates was initiated in the presence of self-assembling amelogenin particles. A series of constant titration rate experiments was performed that allowed for a gradual increase of the calcium and/or phosphate concentrations in the protein suspensions. We observed a significant amount of apatite crystals formed on the substrates following the titration of rH174 sols that comprised the initial supersaturation ratio equal to zero. The protein layers adsorbed onto the substrate apatite crystals were shown to act as promoters of nucleation and growth of calcium phosphates subsequently formed on the substrate surface. Nucleation lag time experiments have showed that rH174 tends to accelerate precipitation from metastable calcium phosphate solutions in proportion to its concentration. Despite their mainly hydrophobic nature, amelogenin nanospheres, the size and surface charge properties of which were analyzed using dynamic light scattering, acted as a nucleating agent for the crystallization of apatite. The biomimetic experimental setting applied in this study proves as convenient for gaining insight into the fundamental nature of the process of amelogenesis.

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

Science.gov (United States)

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

2013-06-01

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

Hydrophobic agglomeration of apatite fines induced by sodium oleate in aqueous solutions

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Bingqiao Yang

2018-06-01

Full Text Available In this work, the hydrophobic agglomeration of apatite fines induced by sodium oleate in aqueous solutions has been investigated through the measurement of agglomeration degree and fractal dimension. The results showed that the agglomeration degree of apatite fines and agglomerates morphology was strongly depended on sodium oleate concentration, pH, stirring speed and time. Better agglomeration degree and more regular agglomerates were achieved at sodium oleate concentration of 5 × 10−5 mol/L under neutral condition. The critical stirring speed for agglomerates rupture was 1000 rev/min, above which, prolonged stirring time would cause breakage and restructure of the agglomerates after a certain stirring time, resulting in lower agglomeration degree and more regular agglomerates. The agglomeration degree of apatite fines could be greatly enhanced with the addition of emulsified kerosene, but only if the apatite surface was hydrophobic enough. Keywords: Hydrophobic agglomeration, Apatite fines, Agglomeration degree, Fractal dimension, Sodium oleate

Geochemistry and genesis of apatite bearing Fe oxide Dizdaj deposit, SE Zanjan

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Ghasem Nabatian

2009-09-01

Full Text Available Sorkheh-Dizaj apatite-iron oxide deposit is located 32 km southeast of Zanjan. The area is situated within the Tarom subzone of Western Alborz-Azarbaijan structural zone. The oldest units at the Sorkheh-Dizaj area are Eocene trachyte, trachyandesite, olivine basalt and volcanoclastic brecciate tuff and lapilli tuff which intruded by a quartz-monzonite, monzonite and granite subvolcanic pluton of Upper Eocene- Early Oligocene age. Subvolcanic plutonic rocks in the area show characteristics of the I-type granites. Magmatism of the area is of synorogenic to postorogenic related to magmatic arc environments. Mineralization at the area is divided into three main zones (A, B and C that all of which are located in the host subvolcanic pluton. These three zones are similar in terms of host rock, mineralogy, alteration, structure, texture and metal content. Mineralization in the volcanic rocks occurs as veins similar to those in three main zones, but less abundant. Geometry of the ore bodies is of vein type and their textures are stockwork, massive, banded, brecciate and vein-veinlet. The most important minerals at Sorkheh-Dizaj deposit are magnetite (low Ti and apatite that associated with them minor sulfide minerals such as chalcopyrite, bornite and pyrite. Minerals such as ilmenite, spinel (titanium magnetite, galena and sphalerite occur in low contents. The supergene minerals like chalcocite, malachite, azurite, covellite, hematite and goethite have been formed due to weathering and supergene processes. The main alterations at the deposit are K-feldspar metasomatism, actinolitization, argillic, sericitization, silicification, tourmalinization, and chlorite-epidotic. Rare earth elements (REE studies demonstrate that the deposit is more enriched in LREE than in HREE. The REE patterns in the apatite, magnetite and host rocks are similar suggesting a magmatic relationship. The REE contents of the apatites are higher than those of the host rocks and

Preparation of a non-woven poly(ε-caprolactone) fabric with partially embedded apatite surface for bone tissue engineering applications by partial surface melting of poly(ε-caprolactone) fibers.

Science.gov (United States)

Kim, In Ae; Rhee, Sang-Hoon

2017-07-01

This article describes a novel method for the preparation of a biodegradable non-woven poly(ε-caprolactone) fabric with a partially embedded apatite surface designed for application as a scaffold material for bone tissue engineering. The non-woven poly(ε-caprolactone) fabric was generated by the electro-spinning technique and then apatite was coated in simulated body fluid after coating the PVA solution containing CaCl 2 ·2H 2 O. The apatite crystals were partially embedded or fully embedded into the thermoplastic poly(ε-caprolactone) fibers by controlling the degree of poly(ε-caprolactone) fiber surface melting in a convection oven. Identical apatite-coated poly(ε-caprolactone) fabric that did not undergo heat-treatment was used as a control. The features of the embedded apatite crystals were evaluated by FE-SEM, AFM, EDS, and XRD. The adhesion strengths of the coated apatite layers and the tensile strengths of the apatite coated fabrics with and without heat-treatment were assessed by the tape-test and a universal testing machine, respectively. The degree of water absorbance was assessed by adding a DMEM droplet onto the fabrics. Moreover, cell penetrability was assessed by seeding preosteoblastic MC3T3-E1 cells onto the fabrics and observing the degrees of cell penetration after 1 and 4 weeks by staining nuclei with DAPI. The non-woven poly(ε-caprolactone) fabric with a partially embedded apatite surface showed good water absorbance, cell penetrability, higher apatite adhesion strength, and higher tensile strength compared with the control fabric. These results show that the non-woven poly(ε-caprolactone) fabric with a partially embedded apatite surface is a potential candidate scaffold for bone tissue engineering due to its strong apatite adhesion strength and excellent cell penetrability. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 1973-1983, 2017. © 2017 Wiley Periodicals, Inc.

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

Science.gov (United States)

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

Formation of an ascorbate-apatite composite layer on titanium

Energy Technology Data Exchange (ETDEWEB)

Ito, Atsuo [National Institute of Advanced Industrial Science and Technology (AIST), Institute for Human Science and Biomedical Engineering, Central 6, Higashi 1-1-1, Tsukuba, Ibaraki 305-8566 (Japan); Sogo, Yu [National Institute of Advanced Industrial Science and Technology (AIST), Institute for Human Science and Biomedical Engineering, Central 6, Higashi 1-1-1, Tsukuba, Ibaraki 305-8566 (Japan); Ebihara, Yuko [School of Science and Technology, Waseda University, 3-4-1 Okubo, Sinjuku-ku, Tokyo 169-8050 (Japan); Onoguchi, Masahiro [School of Science and Technology, Waseda University, 3-4-1 Okubo, Sinjuku-ku, Tokyo 169-8050 (Japan); Oyane, Ayako [National Institute of Advanced Industrial Science and Technology (AIST), Nanotechnology Research Institute, Central 4, Higashi 1-1-1, Tsukuba, Ibaraki 305-8562 (Japan); Ichinose, Noboru [School of Science and Technology, Waseda University, 3-4-1 Okubo, Sinjuku-ku, Tokyo 169-8050 (Japan)

2007-09-15

An ascorbate-apatite composite layer was successfully formed on NaOH- and heat-treated titanium by coprecipitating L-ascorbic acid phosphate and low-crystalline apatite in a supersaturated calcium phosphate solution at 37 {sup 0}C for 48 h. The supersaturated calcium phosphate solutions used have chemical compositions attainable by mixing infusion fluids officially approved for clinical use. The amount of immobilized L-ascorbic acid phosphate ranged from 1.0 to 2.3 {mu}g mm{sup -2}, which is most likely to be sufficient for the in vitro osteogenic differentiation of mesenchymal stem cells on titanium. Since ascorbate is important for the collagen synthesis and subsequent osteogenesis of mesenchymal stem cells, titanium coated with the ascorbate-apatite composite layer would be useful as a scaffold in bone tissue engineering and as a bone substitute.

Formation of an ascorbate-apatite composite layer on titanium

International Nuclear Information System (INIS)

Ito, Atsuo; Sogo, Yu; Ebihara, Yuko; Onoguchi, Masahiro; Oyane, Ayako; Ichinose, Noboru

2007-01-01

An ascorbate-apatite composite layer was successfully formed on NaOH- and heat-treated titanium by coprecipitating L-ascorbic acid phosphate and low-crystalline apatite in a supersaturated calcium phosphate solution at 37 0 C for 48 h. The supersaturated calcium phosphate solutions used have chemical compositions attainable by mixing infusion fluids officially approved for clinical use. The amount of immobilized L-ascorbic acid phosphate ranged from 1.0 to 2.3 μg mm -2 , which is most likely to be sufficient for the in vitro osteogenic differentiation of mesenchymal stem cells on titanium. Since ascorbate is important for the collagen synthesis and subsequent osteogenesis of mesenchymal stem cells, titanium coated with the ascorbate-apatite composite layer would be useful as a scaffold in bone tissue engineering and as a bone substitute

High spatial resolution U-Pb geochronology and Pb isotope geochemistry of magnetite-apatite ore from the Pea Ridge iron oxide-apatite deposit, St. Francois Mountains, southeast Missouri, USA

Science.gov (United States)

Neymark, Leonid; Holm-Denoma, Christopher S.; Pietruszka, Aaron; Aleinikoff, John N.; Fanning, C. Mark; Pillers, Renee M.; Moscati, Richard J.

2016-01-01

The Pea Ridge iron oxide-apatite (IOA) deposit is one of the major rhyolite-hosted magnetite deposits of the St. Francois Mountains terrane, which is located within the Mesoproterozoic (1.5–1.3 Ga) Granite-Rhyolite province in the U.S. Midcontinent. Precise and accurate determination of the timing and duration of oreforming processes in this deposit is crucial for understanding its origin and placing it within a deposit-scale and regional geologic context. Apatite and monazite, well-established U-Pb mineral geochronometers, are abundant in the Pea Ridge orebody. However, the potential presence of multiple generations of dateable minerals, processes of dissolution-reprecipitation, and occurrence of micrometer-sized intergrowths and inclusions complicate measurements and interpretations of the geochronological results. Here, we employ a combination of several techniques, including ID-TIMS and high spatial resolution geochronology of apatite and monazite using LA-SC-ICPMS and SHRIMP, and Pb isotope geochemistry of pyrite and magnetite to obtain the first direct age constraints on the formation and alteration history of the Pea Ridge IOA deposit. The oldest apatite TIMS 207Pb*/206Pb* dates are 1471 ± 1 and 1468 ± 1 Ma, slightly younger than (but within error of) the ~1474 to ~1473 Ma U-Pb zircon ages of the host rhyolites. Dating of apatite and monazite inclusions within apatite provides evidence for at least one younger metasomatic event at ~1.44 Ga, and possibly multiple superimposed metasomatic events between 1.47 and 1.44 Ga. Lead isotop analyses of pyrite show extremely radiogenic 206Pb/204Pb ratios up to ~80 unsupported by in situ U decay. This excess radiogenic Pb in pyrite may have been derived from the spatially associated apatite as apatite recrystallized several tens of million years after its formation. The low initial 206Pb/204Pb ratio of ~16.5 and 207Pb/204Pb ratio of ~15.4 for individual magnetite grains indicate closed U-Pb system behavior in

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

Energy Technology Data Exchange (ETDEWEB)

NONE

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.

Assessment of copper removal from highway stormwater runoff using Apatite II(TM) and compost : laboratory and field testing.

Science.gov (United States)

2015-03-01

-Stormwater runoff introduces heavy metals to surface waters that are harmful to aquatic organisms, : including endangered salmon. This work evaluates Apatite II, a biogenic fish bone based adsorbent, for removing metal : from stormwater. The meta...

Study on removal effect and mechanism of uranium by hydroxyapatite and natural apatite

International Nuclear Information System (INIS)

Zhang Xiaofeng; Chen Diyun; Tu Guoqing; Huang Xiaozhui

2014-01-01

By the static experiments, the effects of reaction time, pH value, initial concentration of uranium, dosage of apatite on adsorption of hydroxyapatite and natural apatite for uranium were studied respectively. The adsorption process was analyzed by thermodynamics and kinetics, and the adsorption mechanism was analyzed by infrared spectroscopy, X-ray diffraction and scanning electron microscope. The results of hydroxyapatite show that the removal capacity of uranium increases with the initial concentration of uranium, and the adsorption rate of hydroxyapatite on UO_2"2"+ reaches 85%, when the pH value is 4 to 5 and dosage of hydroxyapatite is 0.75 g. The results of natural apatite show that the removal capacity of uranium increases with the initial concentration of uranium, and the adsorption rate of natural apatite on UO_2"2"+ is up to 80%, when the pH value is 3 and dosage of hydroxyapatite is l.0 g. Similarly, at 120 minutes both of the removal reactions by hydroxyapatite and natural apatite substantially reach equilibrium. Moreover, both of the reactions by hydroxyapatite and natural apatite are in line with quasi secondary dynamics equation, and follow the Langmuir adsorption isotherm. Infrared spectra indicate that the removal of hydroxyapatite for uranium depends on the complexation of phosphate, which is almost the same as that of natural apatite. X-ray diffraction analysis shows that hydroxyapatite has the composition and structure of pure material, whereas the natural apatite is mainly composed of Ca_5H_2(PO_4)_3F and Ca_8H_2(PO_4)_6H_2O. In addition, scanning electron microscope demonstrates that hydroxyapatite has the appearance of spherical with a hole and the hole has a cavity containing a large amount of floc, while the surface becomes smooth and pores are closed after removal of uranium, which is due to the adsorption of UO_2"2"+ leading a link between molecules on hydroxyapatite surface. But for natural apatite, it depicts the angular mineral shape

Sub-µm structure and volatile distribution of shocked lunar apatite

Science.gov (United States)

Cernok, A.; White, L. F.; Darling, J.; Dunlop, J.; Fougerouse, D.; William, R. D. A.; Reddy, S.; Saxey, D. W.; Zhao, X.; Franchi, I.; Anand, M.

2017-12-01

Apatite is a key mineral broadly used for studying volatiles in planetary materials. Most studies in this recent frontier of planetary exploration focus on volatile content and respective isotopic composition in apatite. However, there is an imperative to contextualize geochemical data with impact-induced features, given that most planetary materials experienced at least some shock deformation. This study aims at understanding the effect of high-level shock deformation on volatile distribution in apatite from lunar highlands samples. Combining Electron Backscatter Diffraction (EBSD), NanoSIMS and Atom Probe Microscopy (APM) analyses we are gaining an insight into the µm- and nm-scale structural variation in apatite from a shocked, maskelynite- and impact-melt-bearing norite. EBSD revealed degraded crystallinity, high density of low angle grain boundaries and domains of sub-µm granular features that appear amorphous at this length scales ( 80 x 40 nm). Texture component maps show up to 25° misorientation within a single grain - evidence of severe crystal-plastic deformation, but with no obvious evidence of recrystallization. APM revealed complex microstructure of the apparently amorphous domains defined by well developed, straight to slightly curved grain boundaries meeting at 120° triple junctions. This equilibrium texture is probably accommodated by annealing and recrystallization of apatite due to the post-shock heating. Crystallites range in size from 50 to 100 nm. Grain boundaries are defined by segregation of Mg, Si and Fe impurities, which possibly originate from surrounding phases. Cl and F show homogenous distribution over the length scale of the APM analysis (1 to 500 nm). H2O content measurements of 250-600 ppm by NanoSIMS are consistent with the lower range of previously reported values for this rock, with no obvious correlation with the level of crystallinity. δD values are confirmed to be terrestrial-like and relatively constant. These preliminary

Influence of Common Bean (Phaseolus vulgaris) Grown in Elevated CO2 on Apatite Dissolution

Science.gov (United States)

Olsen, A. A.; Morra, B.

2016-12-01

We ran a series of experiments to test the hypothesis that release of plant nutrients contained in apatite will be accelerated by the growth of Langstrath Stringless green bean in the presence of atmospheric CO2 meant to simulate possible future atmospheric conditions due a higher demand of nutrients and growth rate caused by elevated CO2. We hypothesize that elevated atmospheric CO2 will lead to both increased root growth and organic acid exudation. These two traits will lead to improved acquisition of P derived from apatite. Experiments were designed to investigate the effect of these changes on soil mineral weathering using plants grown under two conditions, ambient CO2 (400ppm) and elevated CO2 (1000ppm). Plants were grown in flow-through microcosms consisting of a mixture of quartz and apatite sands. Mini-greenhouses were utilized to control CO2 levels. Plant growth was sustained by a nutrient solution lacking in Ca and P. Calcium and P content of the leachate and plant tissue served as a proxy for apatite dissolution. Plants were harvested biweekly during the eight-week experiment and analyzed for Ca and P to calculate apatite dissolution kinetics. Preliminary results suggest that approximately four times more P and Ca are present in the leachate from experiments containing plants under both ambient and elevated CO2 levels than in abiotic experiments; however, the amounts of both P and Ca released in experiments conducted under both ambient and elevated CO2 levels are similar. Additionally, the amount of P in plant tissue grown under ambient and elevated CO2 conditions is similar. Plants grown in elevated CO2 had a greater root to shoot ratio. The planted microcosms were found to have a lower pH than abiotic controls most likely due to root respiration and exudation of organic acids.

Rare Earth Element Behaviour in Apatite from the Olympic Dam Cu–U–Au–Ag Deposit, South Australia

Directory of Open Access Journals (Sweden)

Sasha Krneta

2017-08-01

Full Text Available Apatite is a common magmatic accessory in the intrusive rocks hosting the giant ~1590 Ma Olympic Dam (OD iron-oxide copper gold (IOCG ore system, South Australia. Moreover, hydrothermal apatite is a locally abundant mineral throughout the altered and mineralized rocks within and enclosing the deposit. Based on compositional data for zoned apatite, we evaluate whether changes in the morphology and the rare earth element and Y (REY chemistry of apatite can be used to constrain the fluid evolution from early to late hydrothermal stages at OD. The ~1.6 Ga Roxby Downs granite (RDG, host to the OD deposit, contains apatite as a magmatic accessory, locally in the high concentrations associated with mafic enclaves. Magmatic apatite commonly contains REY-poor cores and REY-enriched margins. The cores display a light rare earth element (LREE-enriched chondrite-normalized fractionation pattern with a strong negative Eu anomaly. In contrast, later hydrothermal apatite, confined to samples where magmatic apatite has been obliterated due to advanced hematite-sericite alteration, displays a conspicuous, convex, middle rare earth element (MREE-enriched pattern with a weak negative Eu anomaly. Such grains contain abundant inclusions of florencite and sericite. Within high-grade bornite ores from the deposit, apatite displays an extremely highly MREE-enriched chondrite-normalized fractionation trend with a positive Eu anomaly. Concentrations of U and Th in apatite mimic the behaviour of ∑REY and are richest in magmatic apatite hosted by RDG and the hydrothermal rims surrounding them. The shift from characteristic LREE-enriched magmatic and early hydrothermal apatite to later hydrothermal apatite displaying marked MREE-enriched trends (with lower U, Th, Pb and ∑REY concentrations reflects the magmatic to hydrothermal transition. Additionally, the strong positive Eu anomaly in the MREE-enriched trends of apatite in high-grade bornite ores are attributable to

Field Implementation Plan for the In-Situ Bioremediation Treatability Study at the Technical Area-V Groundwater Area of Concern

Energy Technology Data Exchange (ETDEWEB)

Li, Jun [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2016-10-31

This Field Implementation Plan (FIP) was prepared by Sandia National Laboratories, New Mexico (SNL/NM) and provides instruction on conducting a series of in-situ bioremediation (ISB) tests as described in the Revised Treatability Study Work Plan for In-Situ Bioremediation at the Technical Area-V Groundwater Area of Concern, referred to as the Revised Work Plan in this FIP. The Treatability Study is designed to gravity inject an electron-donor substrate and bioaugmentation bacteria into groundwater via three injection wells to perform bioremediation of the constituents of concern (COCs), nitrate and trichloroethene (TCE), in the regions with the highest concentrations at the Technical Area-V Groundwater (TAVG) Area of Concern (AOC). The Treatability Study will evaluate the effectiveness of bioremediation solution delivery and COC treatment over time. This FIP is designed for SNL/NM work planning and management. It is not intended to be submitted for regulator’s approval. The technical details presented in this FIP are subject to change based on field conditions, availability of equipment and materials, feasibility, and inputs from Sandia personnel and Aboveground Injection System contractor.

Field Implementation Plan for the In-Situ Bioremediation Treatability Study at the Technical Area-V Groundwater Area of Concern

International Nuclear Information System (INIS)

Li, Jun

2016-01-01

This Field Implementation Plan (FIP) was prepared by Sandia National Laboratories, New Mexico (SNL/NM) and provides instruction on conducting a series of in-situ bioremediation (ISB) tests as described in the Revised Treatability Study Work Plan for In-Situ Bioremediation at the Technical Area-V Groundwater Area of Concern, referred to as the Revised Work Plan in this FIP. The Treatability Study is designed to gravity inject an electron-donor substrate and bioaugmentation bacteria into groundwater via three injection wells to perform bioremediation of the constituents of concern (COCs), nitrate and trichloroethene (TCE), in the regions with the highest concentrations at the Technical Area-V Groundwater (TAVG) Area of Concern (AOC). The Treatability Study will evaluate the effectiveness of bioremediation solution delivery and COC treatment over time. This FIP is designed for SNL/NM work planning and management. It is not intended to be submitted for regulator's approval. The technical details presented in this FIP are subject to change based on field conditions, availability of equipment and materials, feasibility, and inputs from Sandia personnel and Aboveground Injection System contractor.

Process and equipment development for hot isostatic pressing treatability study

Energy Technology Data Exchange (ETDEWEB)

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.

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

Science.gov (United States)

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...

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

Science.gov (United States)

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. Copyright © 2015 Elsevier Ltd. All rights reserved.

Study of damage and helium diffusion in fluoro-apatites

International Nuclear Information System (INIS)

Miro, S.

2004-12-01

This work lies within the scope of the study of the radionuclides containment matrices. The choice of the fluoro-apatites as potential matrices of containment was suggested by the notable properties of these latter (thermal and chemical stability even under radioactive radiation). By irradiations with heavy ions and a helium implantation we simulated the effects related to the alpha radioactivity and to the spontaneous nuclear fission of the radionuclides. Thanks to the study of Durango fluoro-apatite single crystals and fluoro-apatite sintered ceramics, we evidenced that the damage fraction as well as the unit cell deformations increase with the electronic energy loss and with the substitution. These effects are followed at high fluences by a phenomenon of re-crystallization. The study of the helium diffusion points out that the thermal diffusion process improves with the substitution and strongly increases with heavy ions irradiation. (author)

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

Science.gov (United States)

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.

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

Energy Technology Data Exchange (ETDEWEB)

Chowdhury, E.H., E-mail: md.ezharul.hoque@med.monash.edu.my [Jeffrey Cheah School of Medicine and Health Sciences, Monash University Sunway Campus, Jalan Lagoon Selatan, Bandar Sunway, Selangor Darul Ehsan (Malaysia)

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.

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

International Nuclear Information System (INIS)

Chowdhury, E.H.

2011-01-01

Highlights: → Cytoplasmic stability of plasmid DNA is enhanced by fluoride incorporation into carbonate apatite carrier. → Fluoridated carbonate apatite promotes a robust increase in transgene expression. → 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.

Improvement of RVNRL film properties by adding fumed silica and hydroxy apatite

Directory of Open Access Journals (Sweden)

Adul Thiangchanya

2003-01-01

Full Text Available The effect of adding fumed silica and hydroxy apatite to Radiation Vulcanized Natural Rubber Latex (RVNRL for improving tear strength, aging properties, degradability and water-soluble protein content of rubber films has been investigated. The addition of fumed silica and hydroxy apatite in RVNRL improves tear strength and aging properties of rubber films, whereas tensile strength and degradability of rubber films were unchanged during storage at room temperature. The water-soluble protein content in rubber films was reduced by immobilization of the fumed silica and hydroxy apatite and enhanced by addition of ZnO. This may reduce allergy problems of natural rubber latex products caused by water-soluble protein. The MST of the RVNRL with fumed silica and hydroxy apatite indicated that the latex must be used within two months after mixing because of its stability.

Bone tissue engineering on amorphous carbonated apatite and crystalline octacalcium phosphate-coated titanium discs

NARCIS (Netherlands)

Dekker, Robert J.; de Bruijn, Joost Dick; Stigter, Martin; Barrère, F.; Layrolle, Pierre; van Blitterswijk, Clemens

2005-01-01

Poor fixation of bone replacement implants, e.g. the artificial hip, in implantation sites with inferior bone quality and quantity may be overcome by the use of implants coated with a cultured living bone equivalent. In this study, we tested, respectively, amorphous carbonated apatite (CA)- and

Dispersion of uranium in accessory apatite in crystalline rocks and its possible petrogenetic meaning

International Nuclear Information System (INIS)

Kral, J.; Burchart, J.

1983-01-01

The coefficient of variation for grain-by-grain fission track uranium analysis of apatites from igneous rocks seems to reflect the temperature of crystallization and the cooling rate. For metamorphic rocks the coefficient represents a complex record of the homogeneity of the source and of metamorphic neocrystallization. As a test case 41 West Carpathian rocks have been examined and the coefficients of variation for U in apatites found to be: granitic rocks 0.30-0.79, paragneisses 0.35-0.95, migmatites 0.55-0.87, and volcanic rocks 0.30-0.40. Most of the frequency distributions are lognormal, though for some cases a normal distribution gives a better fit, and some are incompatible with either of the two distributions. (orig.)

Apatite in carbonatitic rocks: Compositional variation, zoning, element partitioning and petrogenetic significance

Science.gov (United States)

Chakhmouradian, Anton R.; Reguir, Ekaterina P.; Zaitsev, Anatoly N.; Couëslan, Christopher; Xu, Cheng; Kynický, Jindřich; Mumin, A. Hamid; Yang, Panseok

2017-03-01

Apatite-group phosphates are nearly ubiquitous in carbonatites, but our understanding of these minerals is inadequate, particularly in the areas of element partitioning and petrogenetic interpretation of their compositional variation among spatially associated rocks and within individual crystals. In the present work, the mode of occurrence, and major- and trace-element chemistry of apatite (sensu lato) from calcite and dolomite carbonatites, their associated cumulate rocks (including phoscorites) and hydrothermal parageneses were studied using a set of 80 samples from 50 localities worldwide. The majority of this set represents material for which no analytical data are available in the literature. Electron-microprobe and laser-ablation mass-spectrometry data ( 600 and 400 analyses, respectively), accompanied by back-scattered-electron and cathodoluminescence images and Raman spectra, were used to identify the key compositional characteristics and zoning patterns of carbonatitic apatite. These data are placed in the context of phosphorus geochemistry in carbonatitic systems and carbonatite evolution, and compared to the models proposed by previous workers. The documented variations in apatite morphology and zoning represent a detailed record of a wide range of evolutionary processes, both magmatic and fluid-driven. The majority of igneous apatite from the examined rocks is Cl-poor fluorapatite or F-rich hydroxylapatite (≥ 0.3 apfu F) with 0.2-2.7 wt.% SrO, 0-4.5 wt.% LREE2O3, 0-0.8 wt.% Na2O, and low levels of other cations accommodated in the Ca site (up to 1000 ppm Mn, 2300 ppm Fe, 200 ppm Ba, 150 ppm Pb, 700 ppm Th and 150 ppm U), none of which show meaningful correlation with the host-rock type. Silicate, (SO4)2 - and (VO4)3 - anions, substituting for (PO4)3 -, tend to occur in greater abundance in crystals from calcite carbonatites (up to 4.2 wt.% SiO2, 1.5 wt.% SO3 and 660 ppm V). Although (CO3)2 - groups are very likely present in some samples, Raman micro

Thermodynamic Mixing Behavior Of F-OH Apatite Crystalline Solutions

Science.gov (United States)

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

Magnetite-apatite-dolomitic rocks of Ust-Chulman (Aldan shield, Russia): Seligdar-type carbonatites?

Science.gov (United States)

Prokopyev, Ilya R.; Doroshkevich, Anna G.; Redina, Anna A.; Obukhov, Andrey V.

2018-04-01

The Ust-Chulman apatite ore body is situated within the Nimnyrskaya apatite zone at the Aldan shield in Russia. The latest data confirm the carbonatitic origin of the Seligdar apatite deposit (Prokopyev et al. in Ore Geol Rev 81:296-308, 2017). The results of our investigations demonstrate that the magnetite-apatite-dolomitic rocks of the Ust-Chulman are highly similar to Seligdar-type dolomitic carbonatites in terms of the mineralogy and the fluid regime of formation. The ilmenite and spinel mineral phases occur as solid solutions with magnetite, and support the magmatic origin of the Ust-Chulman ores. The chemical composition of REE- and SO3-bearing apatite crystals and, specifically, monazite-(Ce) mineralisation and the formation of Nb-rutile, late hydrothermal sulphate minerals (barite, anhydrite) and haematite are typical for carbonatite complexes. The fluid inclusions study revealed similarities to the evolutionary trend of the Seligdar carbonatites that included changes of the hydrothermal solutions from highly concentrated chloride to medium-low concentrated chloride-sulphate and oxidized carbonate-ferrous.

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

Energy Technology Data Exchange (ETDEWEB)

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.

IN SITU LEAD IMMOBILIZATION BY APATITE

Science.gov (United States)

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...

Effect of white mineral trioxide aggregate compared with biomimetic carbonated apatite on dentine bridge formation and inflammatory response in a dental pulp model.

Science.gov (United States)

Danesh, F; Vahid, A; Jahanbani, J; Mashhadiabbas, F; Arman, E

2012-01-01

  To evaluate the effects of apatite precipitation on the biocompatibility and hard tissue induction properties of white mineral trioxide aggregate (WMTA) in a dental pulp model.   Pulp exposures were created on the axial walls of 32 sound canine teeth of eight dogs. Four additional sound teeth served as controls. The pulps were capped either with WMTA or apatite derivatives [biomimetic carbonated apatite (BCAp)] in the interaction of WMTA with a synthetic tissue fluid and restored with zinc oxide-eugenol cement. After 7 and 70 days, the animals were killed, and the histological specimens taken from the teeth were stained with haematoxylin and eosin for histomorphological evaluation. The Brown and Brenn technique was employed to stain bacteria. The data were subjected to nonparametric Kruskall-Wallis analysis and Mann-Whitney U_tests.   Biomimetic carbonated apatite did not induce hard tissue bridge formation. WMTA performed significantly better than BCAp in this respect at both periods (P 0.05).   White mineral trioxide aggregate induced hard tissue formation via a mechanism other than that postulated via apatite formation. © 2011 International Endodontic Journal.

A potentially treatable cause of dementia | Katsidzira | Central ...

African Journals Online (AJOL)

A potentially treatable cause of dementia. L Katsidzira, T Machiridza, A Ndlovu. Abstract. No Abstract. Full Text: EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT · AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors · FAQ's · More about ...

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

Science.gov (United States)

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

Evaluation of apatite silicates as solid oxide fuel cell electrolytes

Energy Technology Data Exchange (ETDEWEB)

Marrero-Lopez, D. [Dpto. de Fisica Aplicada I, Laboratorio de Materiales y Superficies (Unidad Asociada al C.S.I.C.), Universidad de Malaga, 29071 Malaga (Spain); Dpto. de Quimica Inorganica, Universidad de La Laguna, 38200 La Laguna, Tenerife (Spain); Martin-Sedeno, M.C.; Aranda, M.A.G. [Dpto. de Quimica Inorganica, Universidad Malaga, 29071 Malaga (Spain); Pena-Martinez, J. [Dpto. de Quimica Inorganica, Universidad de La Laguna, 38200 La Laguna, Tenerife (Spain); Instituto de Energias Renovables, Parque Tecnologico, Universidad de Castilla La Mancha, 02006 Albacete (Spain); Ruiz-Morales, J.C.; Nunez, P. [Dpto. de Quimica Inorganica, Universidad de La Laguna, 38200 La Laguna, Tenerife (Spain); Ramos-Barrado, J.R. [Dpto. de Fisica Aplicada I, Laboratorio de Materiales y Superficies (Unidad Asociada al C.S.I.C.), Universidad de Malaga, 29071 Malaga (Spain)

2010-05-01

Apatite-type silicates have been considered as promising electrolytes for Solid Oxide Fuel Cells (SOFC); however studies on the potential use of these materials in SOFC devices have received relatively little attention. The lanthanum silicate with composition La{sub 10}Si{sub 5.5}Al{sub 0.5}O{sub 26.75} has been evaluated as electrolyte with the electrode materials commonly used in SOFC, i.e. manganite, ferrite and cobaltite as cathode materials and NiO-CGO composite, chromium-manganite and Sr{sub 2}MgMoO{sub 6} as anode materials. Chemical compatibility, area-specific resistance and fuel cell studies have been performed. X-ray powder diffraction (XRPD) analysis did not reveal any trace of reaction products between the apatite electrolyte and most of the aforementioned electrode materials. However, the area-specific polarisation resistance (ASR) of these electrodes in contact with apatite electrolyte increased significantly with the sintering temperature, indicating reactivity at the electrolyte/electrode interface. On the other hand, the ASR values are significantly improved using a ceria buffer layer between the electrolyte and electrode materials to prevent reactivity. Maximum power densities of 195 and 65 mWcm{sup -2} were obtained at 850 and 700 C, respectively in H{sub 2} fuel, using an 1 mm-thick electrolyte, a NiO-Ce{sub 0.8}Gd{sub 0.2}O{sub 1.9} composite as anode and La{sub 0.6}Sr{sub 0.4}Co{sub 0.8}Fe{sub 0.2}O{sub 3-{delta}} as cathode materials. This fuel cell was tested for 100 h in 5%H{sub 2}-Ar atmosphere showing stable performance. (author)

Naturally etched tracks in apatites and the correction of fission track dating

CERN Document Server

Tien, J L

1999-01-01

Naturally etched tracks have been found in apatites from the rapid cooled, high-level Kunon pluton in the Zhangzhou Igneous Complex, SE China. This is manifested by the fact that the apatite fission track (FT) age derived from conventional counting of spontaneous and induced tracks yields a result of 140.6+-6.5 Ma, which is much older than the ages determined using other methods on different minerals from the same rock. When tracks are observed after etching the polished inner sections of the apatite grains, the naturally etched tracks characterized by having hazy boundaries can be distinguished from the normal tracks with sharp boundaries. The age obtained by omitting these fading-resistant hazy tracks, 76.5+-4.0 Ma, indicates the time of the Kunon pluton cooling down to approx 100 deg. C. The corrected peak age (73.8 Ma) is consistent with the other apatite FT peak ages (79.2 to 70.2 Ma) of the nearly contemporaneous plutons in the same igneous complex.

The impact of bacteria of circulating water on apatite-nepheline ore flotation.

Science.gov (United States)

Evdokimova, G A; Gershenkop, A Sh; Fokina, N V

2012-01-01

A new phenomenon has been identified and studied-the impact of bacteria on the benefication process of non-sulphide ores using circulating water supply-a case study of apatite-nepheline ore. It is shown that bacteria deteriorate the floatability of apatite due to their interaction with active centres of calcium-containing minerals and intense flocculation, resulting in a decrease of the flotation process selectivity thus deteriorating the quality of concentrate. Based on the comparative analysis of primary sequences of 16S rRNA genes, there have been identified dominating bacteria species, recovered from the circulating water used at apatite-nepheline concentrating mills, and their phylogenetic position has been determined. All the bacteria were related to γ-Proteobacteria, including the Acinetobacter species, Pseudomonas alcaliphila, Ps. plecoglossicida, Stenotrophomonas rhizophila. A method of non-sulphide ores flotation has been developed with consideration of the bacterial factor. It consists in use of small concentrations of sodium hypochlorite, which inhibits the development of bacteria in the flotation of apatite-nepheline ores.

[Apatite-forming ability of pure titanium implant after micro-arc oxidation treatment].

Science.gov (United States)

Tian, Zhihui; Zhang, Yu; Wang, Lichao; Nan, Kaihui

2013-10-01

To investigate the apatite forming ability of pure titanium implant after micro-arc oxidation treatment in simulated body fluid (SBF) and obtain implants with calcium phosphate (Ca-P) layers. The implants were immersed in (SBF) after micro-arc oxidation treatment for different time lengths, and their apatite forming ability and the morphology and constituents of the Ca-P layers formed on the sample surface were analyzed using X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, and energy dispersive electron probe. After immersion in SBF, large quantities of Ca-P layers were induced on the surface of the samples. The Ca-P layers were composed of octacalcium phosphate and carbonated hydroxyapatite, and the crystals showed a plate-like morphology with an oriented growth. The implants with micro-arc oxidation treatment show good apatite forming ability on the surface with rich calcium and phosphorus elements. The formed layers are composed of bone-like apatite including octacalcium phosphate and carbonated hydroxyapatite.

Theoretical stability assessment of uranyl phosphates and apatites: Selection of amendments for in situ remediation of uranium

International Nuclear Information System (INIS)

Raicevic, S.; Wright, J.V.; Veljkovic, V.; Conca, J.L.

2006-01-01

Addition of an amendment or reagent to soil/sediment is a technique that can decrease mobility and reduce bioavailability of uranium (U) and other heavy metals in the contaminated site. According to data from literature and results obtained in field studies, the general mineral class of apatites was selected as a most promising amendment for in situ immobilization/remediation of U. In this work we presented theoretical assessment of stability of U(VI) in four apatite systems (hydroxyapatite (HAP), North Carolina Apatite (NCA), Lisina Apatite (LA), and Apatite II) in order to determine an optimal apatite soil amendment which could be used for in situ remediation of uranium. In this analysis we used a theoretical criterion which is based on calculation of the ion-ion interaction potential, representing the main term of the cohesive energy of the matrix/pollutant system. The presented results of this analysis indicate (i) that the mechanism of immobilization of U by natural apatites depends on their chemical composition and (ii) that all analyzed apatites represent, from the point of view of stability, promising materials which could be used in field remediation of U-contaminated sites

An extensive apatite fission-track study throughout the Northern Apennines Nappe belt

International Nuclear Information System (INIS)

Abbate, E.; Balestrieri, M.L.; Bigazzi, G.; Ventura, B.; Zattin, M.; Zuffa, G.G.

1999-01-01

This paper takes into consideration more than 100 apatite fission-track analyses on samples coming from an approximately west-east cross-section throughout the Northern Apennines. This collisional chain is made of structural units and nappes (Ligurian and Tuscan Nappe) accreted to the Adriatic Foreland during the Neogene, which overthrust the Miocene turbiditic successions of the Cervarola and Marnoso-arenacea Formations. Different cooling ages and degrees of annealing delineate different evolution histories for these units. Exhumation of the western outcrops of the Ligurian Nappe can be placed at 8 Ma and follows a first denudation event occurred in Eocene times. Timing of exhumation decreases eastwards. A break in this general trend is shown by the Apuan Alps, that occupy an intermediate position and yielded the youngest cooling ages. In the external part of the Marnoso-arenacea foredeep deposits this tendency could not be tested because total annealing of the apatite system has not been reached. In this case, modeling of data allows evaluating maximum burial temperatures

Dural arteriovenous fistula as a treatable dementia.

Science.gov (United States)

Enofe, Ikponmwosa; Thacker, Ike; Shamim, Sadat

2017-04-01

Dementia is a chronic loss of neurocognitive function that is progressive and irreversible. Although rare, dural arteriovenous fistulas (DAVFs) could present with a rapid decline in neurocognitive function with or without Parkinson-like symptoms. DAVFs represent a potentially treatable and reversible cause of dementia. Here, we report the case of an elderly woman diagnosed with a DAVF after presenting with new-onset seizures, deteriorating neurocognitive function, and Parkinson-like symptoms.

Compositional Variation of Terrestrial Mantle Apatites and Implications for the Halogen and Water Budgets of the Terrestrial Mantle

Science.gov (United States)

Roden, M.; Patino Douce, A. E.; Chaumba, J. B.; Fleisher, C.; Yogodzinski, G. M.

2011-12-01

Apatite in ultramafic xenoliths from various tectonic enviroments including arc (Kamchatka), plume (Hawaii), and intraplate (Lunar Crater, Nunivak, Colorado Plateau) were analyzed by electron microprobe with the aim of characterizing the Cl and F contents, and from these measured compositions to infer the nature of fluids/melts that the apatites equilibrated with. The impetus for the study derived from the generalization of O'Reilly and Griffin (1) that mantle-derived metasomatic apatites tend to be Cl-rich and mantle-derived igneous apatites tend to be F-rich. Our work largely corroborates their generalization with Cl- and/or H2O-rich compositions characterizing the apatites from Nunivak and Kamchatka while apatites from igneous or Group II xenoliths tend to be Cl-poor and be either nearly pure fluorapatite or a mix of hydroxylapatite and fluorapatite. We attribute the Cl-rich nature of the Kamchatka apatites to formation from Cl-rich fluids generated from subducted lithosphere; however the Nunivak occurrence is far removed from subducted lithosphere and may reflect a deep seated source for Cl as also indicated by brine inclusions in diamonds, Cl-rich apatites in carbonate-bearing xenoliths and a Cl-rich signature in some plumes such as Iceland, Azores and Samoa. One curious aspect of mantle-derived apatite compositions is that xenoliths with evidence of carbonatitic metasomatism commonly have Cl-rich apatites while apatites from carbonatites are invariably Cl-poor - perhaps reflecting loss of Cl in fluids evolved from the carbonatitic magma. Apatites from Group II xenoliths at Hawaii are solid solutions between fluorapatite and hydroxylapatite and show no evidence for deep-seated Cl at Hawaii. Samples of the terrestrial mantle are almost uniformly characterized by mineral assemblages with a single Ca-rich phosphate phase but the mantles of Mars, Vesta and the Moon have two Ca-rich phosphates, apatite and volatile-poor merrillite - apatite compositions existing

100 Area soil washing bench-scale test procedures

International Nuclear Information System (INIS)

Freeman, H.D.; Gerber, M.A.; Mattigod, S.V.; Serne, R.J.

1993-03-01

This document describes methodologies and procedures for conducting soil washing treatability tests in accordance with the 100 Area Soil Washing Treatability Test Plan (DOE-RL 1992, Draft A). The objective of this treatability study is to evaluate the use of physical separation systems and chemical extraction methods as a means of separating chemically and radioactively contaminated soil fractions from uncontaminated soil fractions. These data will be primarily used for determining feasibility of the individual unit operations and defining the requirements for a system, or systems, for pilot-scale testing

Compression and rupture cycles as tools for compressibility characterization application to apatitic calcium phosphates

Energy Technology Data Exchange (ETDEWEB)

Pontier, C. [S.P.C.T.S., Faculte des Sciences, Limoges (France); G.E.F., Faculte de Pharmacie, Limoges (France); Viana, M.; Chulia, D. [G.E.F., Faculte de Pharmacie, Limoges (France); Champion, E.; Bernache-Assollant, D. [S.P.C.T.S., Faculte des Sciences, Limoges (France)

2002-07-01

Measurement of the cycles of compression and rupture helps to understand the phenomena occurring during compaction. Different parameters are deduced from the cycles, such as the packing of the material and energies used during compression. The ratio between the energy of rupture and the energy of compaction defines the efficacy of compaction of the materials. This technique is applied to ceramic materials using apatitic calcium phosphates with a Ca/P molar ratio of 1.5 (apatitic tricalcium phosphate and {beta}-tricalcium phosphate) and 1.667 (stoichiometric hydroxyapatite). The methodology uses a uniaxial instrumented press to plot the cycles of compaction and rupture. The results point out the good compaction and cohesion properties of apatitic tricalcium phosphate, compared to the other apatitic materials. (orig.)

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

Science.gov (United States)

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

The study of geochemical behavior of rare earth elements in apatites from the Hormoz Island, Persian Gulf

Directory of Open Access Journals (Sweden)

Ali Rostami

2014-04-01

Full Text Available The study area is located about 3 km southwest of the Hormoz Island in the Hormozgan province, in the Persian Gulf. The main rock units in the region consist of a highly altered acidic pluton cratophyre, which is responsible for apatite formation, diabasic dike, marl and altered basalt. Apatite is the only phosphate mineral in the Hormoz Island, which has accumulated REE in its crystal structure. The amount of Na2O and SiO2 oxides in apatite are high and the average content of the main elements Fe, Mg, Al, Ca are 7.5 ppm, 365 ppm, 2880 ppm and 27.8%, respectively. The Y, Mn, Rb contents increase and Sr decreases with increasing magmatic differentiation. It shows that a moderate magmatic differentiation occurred during the crystallization of apatite. The total REE content in the Hormoz apatite is high (1.22-2.25%. LREE/HREE ratio is also high. This means that Hormoz apatites are enriched in light rare earth elements. The REE normalized pattern shows a negative slope with a negative Eu anomaly. According to various diagrams based on apatite composition, it is deduced that the Hormoz apatites belong to mafic I-type granitoids with high oxidation state (Fe2O3/FeO>1.

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

International Nuclear Information System (INIS)

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

1996-01-01

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 -14 to 10 -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)

Atomic substitutions in synthetic apatite; Insights from solid-state NMR spectroscopy

Science.gov (United States)

Vaughn, John S.

Apatite, Ca5(PO4)3X (where X = F, Cl, or OH), is a unique mineral group capable of atomic substitutions for cations and anions of varied size and charge. Accommodation of differing substituents requires some kind of structural adaptation, e.g. new atomic positions, vacancies, or coupled substitutions. These structural adaptations often give rise to important physicochemical properties relevant to a range of scientific disciplines. Examples include volatile trapping during apatite crystallization, substitution for large radionuclides for long-term storage of nuclear fission waste, substitution for fluoride to improve acid resistivity in dental enamel composed dominantly of hydroxylapatite, and the development of novel biomaterials with enhanced biocompatibility. Despite the importance and ubiquity of atomic substitutions in apatite materials, many of the mechanisms by which these reactions occur are poorly understood. Presence of substituents at dilute concentration and occupancy of disordered atomic positions hinder detection by bulk characterization methods such as X-ray diffraction (XRD) and infrared (IR) spectroscopy. Solid-state nuclear magnetic resonance (NMR) spectroscopy is an isotope-specific structural characterization technique that does not require ordered atomic arrangements, and is therefore well suited to investigate atomic substitutions and structural adaptations in apatite. In the present work, solid-state NMR is utilized to investigate structural adaptations in three different types of apatite materials; a series of near-binary F, Cl apatite, carbonate-hydroxylapatite compositions prepared under various synthesis conditions, and a heat-treated hydroxylapatite enriched in 17O. The results indicate that hydroxyl groups in low-H, near binary F,Cl apatite facilitate solid-solution between F and Cl via column reversals, which result in average hexagonal symmetry despite very dilute OH concentration ( 2 mol percent). In addition, 19F NMR spectra indicate

Deep Vadose Zone Treatability Test for the Hanford Central Plateau: Interim Post-Desiccation Monitoring Results, Fiscal Year 2014

Energy Technology Data Exchange (ETDEWEB)

Truex, Michael J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Strickland, Christopher E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Johnson, Christian D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Johnson, Timothy C. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Clayton, Ray E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Chronister, Glen B. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

2014-09-01

Over decades of operation, the U.S. Department of Energy (DOE) and its predecessors have released nearly 2 trillion L (450 billion gal.) of liquid into the vadose zone at the Hanford Site. Much of this discharge of liquid waste into the vadose zone occurred in the Central Plateau, a 200 km² (75 mi²) area that includes approximately 800 waste sites. Some of the inorganic and radionuclide contaminants in the deep vadose zone at the Hanford Site are at depths below the limit of direct exposure pathways, but may need to be remediated to protect groundwater. The Tri-Party Agencies (DOE, U.S. Environmental Protection Agency, and Washington State Department of Ecology) established Milestone M 015 50, which directed DOE to submit a treatability test plan for remediation of technetium-99 (Tc-99) and uranium in the deep vadose zone. These contaminants are mobile in the subsurface environment and have been detected at high concentrations deep in the vadose zone, and at some locations have reached groundwater. Testing technologies for remediating Tc-99 and uranium will also provide information relevant for remediating other contaminants in the vadose zone. A field test of desiccation is being conducted as an element of the DOE test plan published in March 2008 to meet Milestone M 015 50. 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 3 years of post-desiccation monitoring data. The DOE field test plan proscribes a total of 5 years of post-desiccation monitoring.

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

Directory of Open Access Journals (Sweden)

Ayako Oyane

2013-09-01

Full Text Available 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.

LOSS OF ORGANIC CHEMICALS IN SOIL: PURE COMPOUND TREATABILITY STUDIES

Science.gov (United States)

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 ...

Preparation and Characterization of Apatitic Biphasic Calcium Phosphate

International Nuclear Information System (INIS)

Thin Thin Nwe; Kyaw Naing; Khin Mar Tun; Nyunt Wynn

2005-09-01

The apatitic biphasic calcium phosphate (ABcp) consisting of hydroxyapatite (HA) and -tricalcium phosphate ( -Tcp) has been prepared by precipitation technique using slaked lime and orthophosphoric acid. The X-ray diffraction analysis of the product I (hydroxyapatite) revealed that ABcp was partially crystalline state. However, on heating at 800 C for 8 hrs, XRD pattern indicated a perfectly crystalline form of ABcp. This observation was supported by FT-IR measurement. The change in morphology regarding in the functional nature was infered by the shift in the FT-IR frequency. The optimization of the apatitic biphasic calcium phosphate was done by the variation of disodium hydrogen phosphate concentration, setting time, hardening time as well as compressive strength. The perpared cement may be used as an artificial substitution bone

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

International Nuclear Information System (INIS)

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

2015-01-01

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, –PO 4 H 2 , –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. - Highlights: • –PO 4 H 2 , –COOH and –OH groups were successfully introduced onto PEEK surface via tailored silanization layer technique. • Bone-like apatite formed uniformly on surface-functionalized PEEK after immersion in SBF, and tightly adhered to the PEEK. • SEM, EDS, FTIR, XPS and XRD results showed that apatite layer is composed of low-crystalline bone-like apatite. • Bone-like apatite coating remarkably enhanced pre

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

International Nuclear Information System (INIS)

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)

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

Science.gov (United States)

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.

Characterization of damaging in apatitic materials irradiated with heavy ions and thermally annealed

International Nuclear Information System (INIS)

Tisserand, R.

2004-12-01

Some minerals belonging to the family of apatite are seen to be potential candidates for use as conditioning matrices or transmutation targets for high level nuclear waste management. Indeed, studies of natural nuclear reactors (Oklo) highlighted the strong ability of these minerals to anneal irradiation damage. In order to determine the global behaviour of these materials, we performed a fundamental study on the evolution of irradiation damage induced by various heavy ions in two apatites: a natural phospho-calcic fluor-apatite from Durango and a synthetic sintered mono-silicated fluor-apatite, called britholite. The damage in these materials was measured by using channelling R.B.S. and X-ray diffraction respectively and by determining an amorphization effective radius Re. The results revealed a similar behaviour for both apatites according to the electronic energy deposit at the entrance of the material. In addition, the effect of an isothermal annealing at 300 C was quantified on a mono-silicated britholite previously irradiated with Kr ions. We highlighted in this case the return of the lattice parameters to their initial values, followed by a partial and slow rebuilding of the crystalline lattice versus the annealing time. Finally, we followed the changes in the morphology of etch pits in the Durango fluor-apatite after acid dissolution as a function of the energy deposit by the ions. We showed that the influence of crystallography leads quickly to opening angles close to 30 degrees. The calculation of etching velocities within the irradiated material highlighted that there is a range of deposit energy where the velocity ratio increases strongly before becoming constant. (author)

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

Science.gov (United States)

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.

Safety assessment for the proposed pilot-scale treatability tests for the 200-UP-1 and 200-ZP-1 groundwater operable units. Revision 1

International Nuclear Information System (INIS)

1994-12-01

This safety assessment provides an analysis of the proposed pilot-scale treatability test activities to be and conducted within the 200 Area groundwater operable units on the Hanford Site. The 200-UP-1 and 200-ZP-1 operable units are located in the 200 West Area of the Hanford Site. These tests will evaluate an ion exchange (IX) water purification treatment system and granular activated carbon (GAC). A detailed engineering analysis of (GAC) adsorption for remediation of groundwater contamination. A detailed engineering analysis of the IX treatment system. The principal source of information for this assessment, states that the performance objective of the treatment systems is to remove 90% of the uranium and technetium-99 ( 99 Tc) from the extracted groundwater at the 200-UP-1 site. The performance objective for 200-ZP-1 is to remove 90% of the carbon tetrachloride (CCl 4 ), chloroform, and trichloroethylene (TCE) from the extracted groundwater

Growth of apatite on chitosan-multiwall carbon nanotube composite membranes

Energy Technology Data Exchange (ETDEWEB)

Yang Jun; Yao Zhiwen [State Key Laboratory of Oral Diseases, West China College of Stomatology, Sichuan University, No 14, 3rd Section South People' s Road, Chengdu 610041 (China); Tang Changyu [Department of Polymer Science and Materials, Sichuan University (China); Darvell, B.W. [Dental Materials Science, Faculty of Dentistry, University of Hong Kong (Hong Kong); Zhang Hualin; Pan Lingzhan; Liu Jingsong [State Key Laboratory of Oral Diseases, West China College of Stomatology, Sichuan University, No 14, 3rd Section South People' s Road, Chengdu 610041 (China); Chen Zhiqing, E-mail: yangj0710@gmail.com [State Key Laboratory of Oral Diseases, West China College of Stomatology, Sichuan University, No 14, 3rd Section South People' s Road, Chengdu 610041 (China)

2009-07-30

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.

Composition dependent thermal annealing behaviour of ion tracks in apatite

Energy Technology Data Exchange (ETDEWEB)

Nadzri, A., E-mail: allina.nadzri@anu.edu.au [Department of Electronic Materials Engineering, Research School of Physics and Engineering, Australian National University, Canberra, ACT 2601 (Australia); Schauries, D.; Mota-Santiago, P.; Muradoglu, S. [Department of Electronic Materials Engineering, Research School of Physics and Engineering, Australian National University, Canberra, ACT 2601 (Australia); Trautmann, C. [GSI Helmholtz Centre for Heavy Ion Research, Planckstrasse 1, 64291 Darmstadt (Germany); Technische Universität Darmstadt, 64287 Darmstadt (Germany); Gleadow, A.J.W. [School of Earth Science, University of Melbourne, Melbourne, VIC 3010 (Australia); Hawley, A. [Australian Synchrotron, 800 Blackburn Road, Clayton, VIC 3168 (Australia); Kluth, P. [Department of Electronic Materials Engineering, Research School of Physics and Engineering, Australian National University, Canberra, ACT 2601 (Australia)

2016-07-15

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.

Fission-track dating of apatite from deep borehole ATK-1 at Atikokan, Ontario

International Nuclear Information System (INIS)

Naeser, C.W.; Crowley, K.D.

1990-01-01

Fission-track age and lengths have been determined on apatite separated from core recovered from the ATK-1 deep borehole at Atikokan, Ontario. The apatite ages decrease down the borehole, from 515 ± 72 Ma at the top to 376 ± 46 Ma at a depth of 993 m. The mean confined track length for fossil fission tracks in the apatite is 12.4 μm. Within the limits of the measurement the track lengths are the same for all the samples. The results of this study indicate that the rocks found currently at the surface have never been heated above ∼100C since Upper Cambrian time

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

Science.gov (United States)

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

Crystal growth of carbonate apatite using a CaCO3 flux.

Science.gov (United States)

Suetsugu, Y; Tanaka, J

1999-09-01

Single crystals of carbonate apatite were grown using a CaCO3 flux under an Ar gas pressure of 55 MPa. The crystals obtained were observed by scanning electron microscopy, optical microscopy and X-ray diffraction. Electron probe microanalyses and thermal analyses were performed. CO3 ions in planar triangle form replaced both OH sites and PO4 tetrahedral sites in the apatite structure: in particular, the OH sites were perfectly substituted by CO3 ions using this method.

The relationship between fission track length and track density in apatite

International Nuclear Information System (INIS)

Laslett, G.M.; Gleadow, A.J.W.; Duddy, I.R.

1984-01-01

Fission track dating is based upon an age equation derived from a random line segment model for fission tracks. This equation contains the implicit assumption of a proportional relationship between the true mean length of fission tracks and their track density in an isotropic medium. Previous experimental investigation of this relationship for both spontaneous and induced tracks in apatite during progressive annealment model in an obvious fashion. Corrected equations relating track length and density for apatite, an anisotropic mineral, show that the proportionality in this case is between track density and a length factor which is a generalization of the mean track length combining the actual length and crystallographic orientation of the track. This relationship has been experimentally confirmed for induced tracks in Durango apatite, taking into account bias in sampling of the track lengths, and the effect of the bulk etching velocity. (author)

Aboveground Injection Sytem Construction and Mecahnical Integrity Test Plan

Energy Technology Data Exchange (ETDEWEB)

Li, Jun [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2017-10-01

An In-Situ Bioremediation (ISB) Pilot Test Treatability Study is planned at Sandia National Laboratories, New Mexico (SNL/NM) Technical Area-V (TA-V) Groundwater Area of Concern. The Treatability Study is designed to gravity inject an electron-donor substrate and bioaugmentation bacteria into groundwater using an injection well. The constituents of concern (COCs) are nitrate and trichloroethene (TCE). The Pilot Test Treatability Study will evaluate the effectiveness of bioremediation and COC treatment over a prescribed period of time. Results of the pilot test will provide data that will be used to evaluate the cost and effectiveness of a fullscale system.

Theoretical basis of remediation of heavy metal contamination by apatite

International Nuclear Information System (INIS)

Raicevic, S.; Mandic, M.; Kaludjerovic, T.

2001-01-01

Recently we have demonstrated the connection between stability of the products of the in situ remediation processes and their values of the ion-ion interaction potential, representing the main term of the cohesive energy. Using this approach, the stability of the products of remediation of Pb and Cd by hydroxyapatite (HAP) was investigated. It has been demonstrated that incorporation of Pb ions from pyromorphite into HAP is followed by a decrease of the cohesive energy, indicating that in remediation of Pb, HAP serves as a source of components necessary for formation of a stabile Pb-apatite phase which is precipitated on the surface of the HAP particles. Contrary, incorporation of Cd from the Cd-apatite into HAP increases the cohesive energy of the system, suggesting that the precipitated Cd-apatite phase is later transformed into a more stabile HAP/Cd solid solution. The presented results of theoretical analysis are in good accordance with the reported experimental results. Based on the results of this analysis, the general criterion for estimation of stability of the products of the in situ remediation processes was proposed. (author)

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

Science.gov (United States)

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.

Apatite and sodalite based glass-bonded waste forms for immobilization of 129I and mixed halide radioactive wastes

Energy Technology Data Exchange (ETDEWEB)

Goel, Ashutosh [Rutgers Univ., New Brunswick, NJ (United States); McCloy, John S. [Washington State Univ., Pullman, WA (United States); Riley, Brian J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Matyas, Josef [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

2017-12-30

The goal of the project was to utilize the knowledge accumulated by the team, in working with minerals for chloride wastes and biological apatites, toward the development of advanced waste forms for immobilizing 129I and mixed-halide wastes. Based on our knowledge, experience, and thorough literature review, we had selected two minerals with different crystal structures and potential for high chemical durability, sodalite and CaP/PbV-apatite, to form the basis of this project. The focus of the proposed effort was towards: (i) low temperature synthesis of proposed minerals (iodine containing sodalite and apatite) leading to the development of monolithic waste forms, (ii) development of a fundamental understanding of the atomic-scale to meso-scale mechanisms of radionuclide incorporation in them, and (iii) understanding of the mechanism of their chemical corrosion, alteration mechanism, and rates. The proposed work was divided into four broad sections. deliverables. 1. Synthesis of materials 2. Materials structural and thermal characterization 3. Design of glass compositions and synthesis glass-bonded minerals, and 4. Chemical durability testing of materials.

Removal of cadmium, copper, nickel, cobalt and mercury from water by Apatite IITM: Column experiments

International Nuclear Information System (INIS)

Oliva, Josep; De Pablo, Joan; Cortina, Jose-Luis; Cama, Jordi; Ayora, Carlos

2011-01-01

Highlights: → The efficiency of Apatite II TM increases as the acidity decreases, then the application of apatite-based materials for metal removal treatments should be restricted to slightly acid to neutral waters. → Because of the preferred process of using phosphate ions to form metal-phosphate precipitates, the mixture with other sources of alkalinity, such as limestone, is proposed to extend the duration of Apatite II TM . → Compared with other reactive materials such as limestone and caustic magnesia that exhibit a reduction of porosity Apatite II TM showed stable hydraulic performance. → The extrapolation of the column durabilities to a 1-m-thick passive treatment suggests that the Apatite II TM filling can be active between 5 and 10 years for an inflow pH exceeding 5. - Abstract: Apatite II TM , a biogenic hydroxyapatite, was evaluated as a reactive material for heavy metal (Cd, Cu, Co, Ni and Hg) removal in passive treatments. Apatite II TM reacts with acid water by releasing phosphates that increase the pH up to 6.5-7.5, complexing and inducing metals to precipitate as metal phosphates. The evolution of the solution concentration of calcium, phosphate and metals together with SEM-EDS and XRD examinations were used to identify the retention mechanisms. SEM observation shows low-crystalline precipitate layers composed of P, O and M. Only in the case of Hg and Co were small amounts of crystalline phases detected. Solubility data values were used to predict the measured column experiment values and to support the removal process based on the dissolution of hydroxyapatite, the formation of metal-phosphate species in solution and the precipitation of metal phosphate. Cd 5 (PO 4 ) 3 OH(s), Cu 2 (PO 4 )OH(s), Ni 3 (PO 4 ) 2 (s), Co 3 (PO 4 ) 2 8H 2 O(s) and Hg 3 (PO 4 ) 2 (s) are proposed as the possible mineral phases responsible for the removal processes. The results of the column experiments show that Apatite II TM is a suitable filling for permeable

Simultaneous incorporation of carbonate and fluoride in synthetic apatites: Effect on crystallographic and physico-chemical properties.

Science.gov (United States)

Yao, Fang; LeGeros, John P; LeGeros, Racquel Z

2009-07-01

The mineral in bone is an impure hydroxyapatite, with carbonate as the chief minor substituent. Fluoride has been shown to stimulate osteoblastic activity and inhibit osteoclastic resorption in vitro. CO(3)- and F-substituted apatite (CFA) has been considered as potential bone graft material for orthopedic and dental applications. The objective of this study was to determine the effects of simultaneously incorporated CO(3) and F on the crystallographic physico-chemical properties of apatite. The results showed that increasing CO(3) and Na content in apatites with relatively constant F concentration caused a decrease in crystallite size and an increase in the extent of calcium release; increasing F content in apatites with relatively constant CO(3) concentration caused an increase in crystallite size and a decrease in the extent of Ca release. These findings suggest that CFAs as bone graft materials of desired solubility can be prepared by manipulating the relative concentrations of CO(3) and F incorporated in the apatite.

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

International Nuclear Information System (INIS)

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

1999-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

Zheng, Yanyan [Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences, Chengdu 610041 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Xiong, Chengdong; Zhang, Shenglan [Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences, Chengdu 610041 (China); Li, Xiaoyu [State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610041 (China); Zhang, Lifang, E-mail: zhanglfcioc@163.com [Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences, Chengdu 610041 (China)

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, –PO{sub 4}H{sub 2}, –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. - Highlights: • –PO{sub 4}H{sub 2}, –COOH and –OH groups were successfully introduced onto PEEK surface via tailored silanization layer technique. • Bone-like apatite formed uniformly on surface-functionalized PEEK after immersion in SBF, and tightly adhered to the PEEK. • SEM, EDS, FTIR, XPS and XRD results showed that apatite layer is composed of low-crystalline bone-like apatite. • Bone-like apatite coating

Treatability Study Report for In SITU Lead Immobilization Using Phosphate-Based Binders

National Research Council Canada - National Science Library

Bricka, R. M; Marwaha, Anirudha; Fabian, Gene L

2008-01-01

.... The treatability study described in this report was designed to develop the information necessary to support the immobilization of lead contaminants in soil by in situ treatment with phosphate-based binders...

Preparation of an apatite-based matrix for the confinement of iodine 129

International Nuclear Information System (INIS)

Audubert, F.

1995-01-01

The aim of this thesis is the study of the conditioning of iodine 129 from the reprocessing of nuclear wastes. Because of its long half life (1.57 10 7 years), the conditioning of iodine 129 requires a matrix stable during several thousands of years. The study of natural minerals allows the selection of mineral phases having a good long term behaviour. In the first part the policy of nuclear wastes management, and in particular of iodine, is recalled. A naturalistic approach is used to define the best conditioning material and the remarkable properties of apatite in this way are described. In the second part, the preparation and physical-chemical characterization of iodo-apatites are described. A demonstration is made that iodine can penetrate inside vanadate or lead phospho-vanadate apatite-based compounds. The third part deals with the preparation of the conditioning material. The sintering reaction under pressure allows the preparation of composite ceramics including iodo-apatite. A multi-layer coating process is defined: coating of PbI 2 with a Pb 3 (VO 4 ) 1.6 (PO 4 ) 0.4 layer and a Ca 10 (PO 4 ) 6 F 2 layer. Sintering is performed at 700 deg. celsius under a 25 MPa pressure. (J.S.)

Physico-chemical and thermochemical studies of the hydrolytic conversion of amorphous tricalcium phosphate into apatite

International Nuclear Information System (INIS)

Somrani, Saida; Banu, Mihai; Jemal, Mohamed; Rey, Christian

2005-01-01

The conversion of amorphous tricalcium phosphate with different hydration ratio into apatite in water at 25 deg. C has been studied by microcalorimetry and several physical-chemical methods. The hydrolytic transformation was dominated by two strong exothermic events. A fast, relatively weak, wetting process and a very slow but strong heat release assigned to a slow internal rehydration and the crystallization of the amorphous phase into an apatite. The exothermic phenomenon related to the rehydration exceeded the crystalline transformation enthalpy. Rehydration occurred before the conversion of the amorphous phase into apatite and determined the advancement of the hydrolytic reaction. The apatitic phases formed evolved slightly with time after their formation. The crystallinity increased whereas the amount of HPO 4 2- ion decreased. These data allow a better understanding of the behavior of biomaterials involving amorphous phases such as hydroxyapatite plasma-sprayed coatings

Sampling and analysis plan for Phase II of the Bear Creek Valley Treatability Study, Oak Ridge Y-12 Plant, Oak Ridge, Tennessee

International Nuclear Information System (INIS)

1997-09-01

The Bear Creek Valley (BCV) Treatability Study is intended to provide site-specific data defining potential treatment technologies applicable to contaminated groundwater and surface water. This project directly supports Alternative 5 of the base action in the BCV Feasibility Study and indirectly supports other alternatives through proof of concept. In that role, the ultimate goal is to install a treatment system that will remove uranium and nitrate from groundwater before it reaches Bear Creek. A secondary goal is the concurrent removal of technetium and several metals that affect ecological risk. This project is intended to produce hydraulic and treatment performance data required to design the treatment system to reach those goals. This project will also generate information that can be applied at other facilities within the Oak Ridge Reservation. This report is the sampling and analysis plan (SAP) for the field work component of Phase II of the BCV Treatability Study. Field work for this phase of the BCV Treatability Study consists of environmental and media testing. The SAP addresses environmental sampling at the S-3 Site at the Oak Ridge Y-12 Plant. Samples will be taken from groundwater, surface water, seeps, effluent from test columns, effluent from an algal mat reactor, and effluent from a pilot-scale wetland. Groundwater, surface water, and seeps will be monitored continuously for field parameters and sampled for analytical parameters during pump tests conducted periodically during the investigation. In-field continuous flow tests will be conducted over an extended time period (5 weeks) to generate data on long-term treatment effects on potential treatment effects on potential treatment media including sorbents and zero valent iron, over 28 weeks for constructed wetlands treatment, and over 24 weeks for algal mats treatment

Waste management plan for phase II of the Bear Creek Valley Treatability study Oak Ridge Y-12 Plant, Oak Ridge, Tennessee

International Nuclear Information System (INIS)

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

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

International Nuclear Information System (INIS)

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-principleclose 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.)

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

Energy Technology Data Exchange (ETDEWEB)

Gilliam, T.M. [Oak Ridge National Lab., TN (United States); Hutchins, D.A. [Martin Marietta Energy Systems, Inc., Oak Ridge, TN (United States); Chodak, P. III [Massachusetts Institute of Technology (United States)

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.).

Quantitative analysis from limited sampling: influence of the chemical composition of apatites on their resistance to irradiation damage

International Nuclear Information System (INIS)

Ribet, I.; Petit, J.C.; CEA Cadarache, 13 - Saint-Paul-lez-Durance

1998-01-01

Apatites are investigated as possible high performance radioactive waste matrices for specific actinides. In this paper, we have quantified the influence of the chemical composition of apatites on their fission-track annealing behaviour. We aimed to evaluate the capability of apatites to self-anneal high densities of radiation damages produced during disposal. The thermal annealing kinetics, at 280 deg. C, of induced fission tracks has been determined for six different apatite compositions. We show that the chemical composition of apatites is a critical parameter with respect to their annealing behaviour. A mathematical treatment of the data, based upon the methodology of optimum design of experiments, allowed the quantification of the role of substitution for two major elements, of the apatite structure (Ca, P), for chlorine and for the two groups of minor elements, actinides (U+Th) and lanthanides (La+Ce+Y), which are relevant in the nuclear waste disposal context. A high actinide content enhances the annealing of fission-tracks in apatites, which is a very favourable feature of these minerals as radioactive waste matrices. This work also points to a new strategy for the best use of information provided by geological samples. In particular, the mathematical methodology proposed here allows, first, to evaluate the 'quality' of the information obtained and, second, to improve it by a proper choice of additional samples to investigate. (authors)

The thermal history of the Bowen Basin: a comparison of apatite fission track analysis and vitrinite reflectance

International Nuclear Information System (INIS)

Marshallsea, S.J.

1987-01-01

Vitrinite reflectance and apatite fission-track analysis (AFTA) are two techiques widely used to assess paleotemperatures of the order of 20-120 deg.C. in sedimentary basins. Whereas vitrinite reflectance is essentially a qualitative technique that gives an integrated measure of the entire thermal history, AFTA can reveal information on the variation of paleotemperatures through time because fission-tracks in apatite are continually produced throughout geological time. An apatite fission track study of the Upper Permian units of the Bowen Basin has offered the opportunity to compare the two paleotemperature indicators and place constraints on the timing of maximum paleotemperatures. The regional pattern of apatite fission-track ages closely coincides with the vitrinite reflectance indicating that maximum paleotemperatures have varied across the Basin with the central region of the Bowen Basin experiencing highest paleotemperatures. The reduction in apatite reflectance fission-track age with increasing reflectance represents the progressive annealing at temperatures around 60-120 deg. C. of those fission-tracks formed prior to the time of maximum temperatures. In those samples giving the youngest apatite fission-track ages all tacks were totally annealed at this time, and the fission-track age in these samples, in the range 90-120 Myr, indicate the time of cooling from the thermal maximum in the Early Cretaceous. 1 ref

BMP4 Expression Following Stem Cells from Human Exfoliated Deciduous and Carbonate Apatite Transplantation on Rattus norvegicus

Directory of Open Access Journals (Sweden)

Tania Saskianti

2018-04-01

Full Text Available Background: Alveolar bone defects in children still have a high incidence. Conventional bone graft technique that has been used as a defect therapy is still not effective, so new techniques with tissue engineering approach are needed. Bone Morphogenetic Protein 4 (BMP4 as one of the indicators of osteogenic differentiation has not been widely studied, especially in the transplantation with combination of Stem Cells from Human Exfoliated Deciduous (SHED and carbonate apatite. Aim and Objectives: This research aimed to determine the expression of BMP4 after SHED and carbonate apatite transplantation on Rattus norvegicus. Material and Methods: The combinations of SHED and carbonate apatite were transplanted on alveolar bone defects of 4 rats (Rattus norvegicus as the treatment groups and another 4 rats were transplanted with carbonate apatite as the control groups. After 21 days, staining with Hematoxylin Eosin (HE and Immunohistochemistry (IHC BMP4 was performed. Results: BMP4 expression in the treatment groups was significantly higher when compared to the control groups. Discussion: Carbonate apatite has low crystallization rate and high osteoconductivity that produce more osteoblasts and increased BMP4 expression. Conclusion: The transplantation of SHED and carbonate apatite increased BMP4 expression as an indicator of osteogenic differentiation in rats.

Sulfur concentration and isotopic variation in apatites from granitic to granodioritic plutons of a Cretaceous Cordilleran Batholith

Science.gov (United States)

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

Solidifications/stabilization treatability study of a mixed waste sludge

International Nuclear Information System (INIS)

Spence, R.D.; Stine, E.F.

1996-01-01

The Department of Energy Oak Ridge Operations Office signed a Federal Facility Compliance Agreement with the US Environmental Protection Agency Region IV regarding mixed wastes from the Oak Ridge Reservation (ORR) subject to the land disposal restriction provisions of the Resource Conservation and Recovery Act (RCRA). This agreement required treatability studies of solidification/stabilization (S/S) on mixed wastes from the ORR. This paper reports the results of the cementitious S/S studies conducted on a waste water treatment sludge generated from biodenitrification and heavy metals precipitation. For the cementitious waste forms, the additives tested were Portland cement, ground granulated blast furnace slag, Class F fly ash, and perlite. The properties measured on the treated waste were density, free-standing liquid, unconfined compressive strength, and TCLP performance. Spiking up to 10,000, 10,000, and 4,400 mg/kg of nickel, lead, and cadmium, respectively, was conducted to test waste composition variability and the stabilization limitations of the binding agents. The results indicated that nickel, lead and cadmium were stabilized fairly well in the high pH hydroxide-carbonate- ''bug bones'' sludge, but also clearly confirmed the established stabilization potential of cementitious S/S for these RCRA metals

Identifying Medical Diagnoses and Treatable Diseases by Image-Based Deep Learning.

Science.gov (United States)

Kermany, Daniel S; Goldbaum, Michael; Cai, Wenjia; Valentim, Carolina C S; Liang, Huiying; Baxter, Sally L; McKeown, Alex; Yang, Ge; Wu, Xiaokang; Yan, Fangbing; Dong, Justin; Prasadha, Made K; Pei, Jacqueline; Ting, Magdalene Y L; Zhu, Jie; Li, Christina; Hewett, Sierra; Dong, Jason; Ziyar, Ian; Shi, Alexander; Zhang, Runze; Zheng, Lianghong; Hou, Rui; Shi, William; Fu, Xin; Duan, Yaou; Huu, Viet A N; Wen, Cindy; Zhang, Edward D; Zhang, Charlotte L; Li, Oulan; Wang, Xiaobo; Singer, Michael A; Sun, Xiaodong; Xu, Jie; Tafreshi, Ali; Lewis, M Anthony; Xia, Huimin; Zhang, Kang

2018-02-22

The implementation of clinical-decision support algorithms for medical imaging faces challenges with reliability and interpretability. Here, we establish a diagnostic tool based on a deep-learning framework for the screening of patients with common treatable blinding retinal diseases. Our framework utilizes transfer learning, which trains a neural network with a fraction of the data of conventional approaches. Applying this approach to a dataset of optical coherence tomography images, we demonstrate performance comparable to that of human experts in classifying age-related macular degeneration and diabetic macular edema. We also provide a more transparent and interpretable diagnosis by highlighting the regions recognized by the neural network. We further demonstrate the general applicability of our AI system for diagnosis of pediatric pneumonia using chest X-ray images. This tool may ultimately aid in expediting the diagnosis and referral of these treatable conditions, thereby facilitating earlier treatment, resulting in improved clinical outcomes. VIDEO ABSTRACT. Copyright © 2018 Elsevier Inc. All rights reserved.

Fission track ages and uranium concentration of apatites of different rocks of South India

International Nuclear Information System (INIS)

Nand Lal; Nagpaul, K.K.; Nagpal, M.K.

1975-01-01

The uranium concentration and ages of apatite grains of various rocks of South India have been measured by fission track technique. The ages range from 100 m.y. to 730 m.y. whereas uranium concentrations vary from 0.5 to 23.8 atom/million atoms of the apatite mineral. The ages agree well with the Deccan volcanic and Ocean Cycle activities. (author)

Preparation of rare earth fluorides from apatite concentrate

International Nuclear Information System (INIS)

Mulyarchuk, I.F.; Voloshchenko, M.V.; Zen'kovich, E.G.; Sumenkova, V.V.; AN Ukrainskoj SSR, Kiev. Inst. Problem Lit'ya)

1980-01-01

The processes of preparation of the rare earths element sum from apatite concentrate of the Khibins, connected with preliminary extraction of rare earth phosphates from nitric acid extract using solvent extraction or direct precipitation from the extract by solution of potassium and ammonium fluorides. The sequence of the processes of the first variant is the following: solvent extraction of rare earths by tributylphosphate from clarified nitric acid extract of apatite with subsequent reextraction of rare earths with water and precipitation of rare earth phosphates from aqueous solution during neutralization by ammonia. In case of fluoride preparation from rare earth phosphate the main attention is paid to precipitation and filtration of fluorides. Technological scheme and cost price of industry for the production of 1800 t of rare earth trifluorides a year are calculated. When taking account of TBP losses according to its solubility the industry cost price is 1O times lower the modern cost of rare earth fluorides

Apatite-brannerite-pitchblende association in hydrothermal quartz veins

International Nuclear Information System (INIS)

Brodin, B.V.; Mel'nikova, A.M.; Osipov, B.S.; Pavlov, E.G.

1976-01-01

A study into the vein quartz mineralization confined to the tectonic zones of crush and silicification in sedimentary-igneous rocks of the lower Paleozoic has been made. The physicochemical characteristics of minerals were studied by way of optical and electron microscopy, chemical, laser-microspectral and X-ray structural analyses, microprobing and alpha-microradiography. 3 mineral associations have been discriminated, representative of the sequence of hydrothermal mineralization. An unusual parogenesis of pitchblende and brannerite with apatite, xenotime and more recent goethite has been revealed. The results are indicative of a medium-low-temperature hydrothermal process occurring at the final stages of formation of uraniferrous quartz veins. By composition and mineralization sequence, the latters are close to low- and medium-temperature uranium-quartz-chlorite-hydromica formations with apatite, coffinite, brannerite and pitchblende. The weak initial metamictization of goethite in veins 80 to 100 million years old is due to the radioactive effect of the submicroscopic radioactive mineral impurity on the crystalline lattice

Apatite Formation and Biocompatibility of a Low Young's Modulus Ti-Nb-Sn Alloy Treated with Anodic Oxidation and Hot Water.

Directory of Open Access Journals (Sweden)

Hidetatsu Tanaka

Full Text Available Ti-6Al-4V alloy is widely prevalent as a material for orthopaedic implants because of its good corrosion resistance and biocompatibility. However, the discrepancy in Young's modulus between metal prosthesis and human cortical bone sometimes induces clinical problems, thigh pain and bone atrophy due to stress shielding. We designed a Ti-Nb-Sn alloy with a low Young's modulus to address problems of stress disproportion. In this study, we assessed effects of anodic oxidation with or without hot water treatment on the bone-bonding characteristics of a Ti-Nb-Sn alloy. We examined surface analyses and apatite formation by SEM micrographs, XPS and XRD analyses. We also evaluated biocompatibility in experimental animal models by measuring failure loads with a pull-out test and by quantitative histomorphometric analyses. By SEM, abundant apatite formation was observed on the surface of Ti-Nb-Sn alloy discs treated with anodic oxidation and hot water after incubation in Hank's solution. A strong peak of apatite formation was detected on the surface using XRD analyses. XPS analysis revealed an increase of the H2O fraction in O 1s XPS. Results of the pull-out test showed that the failure loads of Ti-Nb-Sn alloy rods treated with anodic oxidation and hot water was greater than those of untreated rods. Quantitative histomorphometric analyses indicated that anodic oxidation and hot water treatment induced higher new bone formation around the rods. Our findings indicate that Ti-Nb-Sn alloy treated with anodic oxidation and hot water showed greater capacity for apatite formation, stronger bone bonding and higher biocompatibility for osteosynthesis. Ti-Nb-Sn alloy treated with anodic oxidation and hot water treatment is a promising material for orthopaedic implants enabling higher osteosynthesis and lower stress disproportion.

Bioceramics of apatites: an option for bone regeneration; Bioceramica de apatitas: uma opcao para regeneracao ossea

Energy Technology Data Exchange (ETDEWEB)

Arxer, Eliana Alves; Almeida Filho, Edson de; Guastaldi, Antonio Carlos, E-mail: iarxer@iq.unesp.br [Universidade Estadual Paulista Julio de Mesquita Filho (UNESP), Araraquara, SP (Brazil). Instituto de Quimica

2011-07-01

The bioceramics of calcium phosphate called apatite, are widely used as material for bone replacement and regeneration, due to its similarity to the mineral component of bones and teeth. The apatites are biocompatible, bioactive and integrate with living tissue by the same active process of physiological bone remodeling. These bioceramics may be used in medical, dental and orthopedic applications. In this research, it was used the wet method for the synthesis of the powder and biomimetic method for coating the surface. The Solubility study was performed in the layer deposited, apatite, for possible application as a platform for inorganic drug delivery. The bioceramics were characterized by MEV, DRX, and EDS. The curves of solubility of apatite in coatings showed that the OCP phase had a higher rate of release in the short term (4 days) while the HA phase showed a gradual release throughout the experiment (16 days). (author)

Trace-element and Nd-isotope systematics in detrital apatite of the Po river catchment: Implications for provenance discrimination and the lag-time approach to detrital thermochronology

Science.gov (United States)

Malusà, Marco G.; Wang, Jiangang; Garzanti, Eduardo; Liu, Zhi-Chao; Villa, Igor M.; Wittmann, Hella

2017-10-01

Detrital thermochronology is often employed to assess the evolutionary stage of an entire orogenic belt using the lag-time approach, i.e., the difference between the cooling and depositional ages of detrital mineral grains preserved in a stratigraphic succession. The impact of different eroding sources to the final sediment sink is controlled by several factors, including the short-term erosion rate and the mineral fertility of eroded bedrock. Here, we use apatite fertility data and cosmogenic-derived erosion rates in the Po river catchment (Alps-Apennines) to calculate the expected percentage of apatite grains supplied to the modern Po delta from the major Alpine and Apenninic eroding sources. We test these predictions by using a cutting-edge dataset of trace-element and Nd-isotope signatures on 871 apatite grains from 14 modern sand samples, and we use apatite fission-track data to validate our geochemical approach to provenance discrimination. We found that apatite grains shed from different sources are geochemically distinct. Apatites from the Lepontine dome in the Central Alps show relative HREE enrichment, lower concentrations in Ce and U, and higher 147Sm/144Nd ratios compared to apatites derived from the External Massifs. Derived provenance budgets point to a dominant apatite contribution to the Po delta from the high-fertility Lepontine dome, consistent with the range independently predicted from cosmonuclide and mineral-fertility data. Our results demonstrate that the single-mineral record in the final sediment sink can be largely determined by high-fertility source rocks exposed in rapidly eroding areas within the drainage. This implies that the detrital thermochronology record may reflect processes affecting relatively small parts of the orogenic system under consideration. A reliable approach to lag-time analysis would thus benefit from an independent provenance discrimination of dated mineral grains, which may allow to proficiently reconsider many

Field demonstration of ex situ biological treatability of contaminated groundwater at the Strachan gas plant

International Nuclear Information System (INIS)

Kurz, M.D.; Stepan, D.J.

1997-03-01

A multi-phase study was conducted to deal with the issues of groundwater and soil contamination by sour gas processing plants in Alberta. Phase One consisted of a review of all soil and groundwater monitoring data submitted to Alberta Environment by sour gas plants in accordance with the Canadian Clean Water Act. The current phase involves the development, evaluation and demonstration of selected remediation technologies to address subsurface contamination of sediments and groundwater at sour gas treatment plants with special attention to the presence of natural gas condensate in the subsurface. Results are presented from a pilot-scale biological treatability test that was performed at the Gulf Strachan Natural Gas Processing Plant in Rocky Mountain House, Alberta, where contaminated groundwater from the plant was being pumped to the surface through many recovery wells to control contaminant migration. The recovered groundwater was directed to a pump-and-treat system that consisted of oil-water separation, iron removal, hardness removal, and air stripping, before being reinjected. The pilot-scale biological treatability testing was conducted to evaluate process stability in treating groundwater without pretreatment for iron and hardness reduction and to evaluate the removal of organic contaminants. Results of a groundwater characterization analysis are discussed. Chemical characteristics of the groundwater at the Strachan Gas Plant showed that an ex situ remediation technology would address the dissolved volatile and semi-volatile organic contamination from natural gas condensates, as well as the nitrogenous compounds resulting from the use of amine-based process chemicals. 4 refs., 5 tabs., 4 figs

Enhancement of the ALP activity of C3H10T1/2 cells by the combination of an oxysterol and apatite

International Nuclear Information System (INIS)

Son, Kyung Mi; Park, Hee Chul; Kim, Na Ryoung; Yang, Hyeong-Cheol; Lee, In-Seop

2010-01-01

Biomimetic apatite coating has been used to load osteogenic biomolecules onto the surface of titanium implants. Apatite on the surface of biomaterials is thought to function as a reservoir of biomolecules as well as enhancing osteoconductivity. In this study, 20α-hydroxycholesterol (20α-HC), an osteogenic oxysterol, was used to induce differentiation of a mouse embryo fibroblast cell line (C3H10T1/2) by loading the oxysterol on biomimetically coated apatite of titanium discs. We found that the phosphatase (alkaline phosphatase (ALP)) activity of 20α-HC was significantly higher with ascorbic acid than alone, suggesting a need for ascorbic acid as a co-factor. When 20α-HC was added into the apatite coating solution, the ALP activity of the C3H10T1/2 cells did not increase on the apatite surface, even in the presence of ascorbic acid. However, ALP activity increased dramatically when 20α-HC was loaded by volatilization of EtOH from the apatite coat after dipping discs in 20α-HC-dissolved EtOH. Interestingly, ascorbic acid was not needed for this increase in ALP activity, suggesting a synergistic effect of 20α-HC and apatite. The concentration of calcium ions, a major component of apatite, affected the osteogenic effect of 20α-HC, and the increase in ALP activity was attenuated by L-type calcium channel inhibitors, verapamil and nifedipine. These results demonstrate that calcium ions released from apatite are important in the synergistic effect of 20α-HC and apatite.

Lead orthovanadate and some vanadium-lead compounds with the apatite structure

Energy Technology Data Exchange (ETDEWEB)

Baran, E J; Botto, I L; Aymonino, P J [La Plata Univ. Nacional (Argentina). Facultad de Ciencias Exactas

1976-06-01

The infrared and Raman spectra of Pb/sub 3/(VO/sub 4/)/sub 2/ are recorded and discussed with the aid of the 'site symmetry' rules. The i.r. spectra of the compounds Pb/sub 5/(VO/sub 4/)/sub 3/X (X=F, Cl, Br), Pb/sub 5/(VO/sub 4/)/sub 2/GeO/sub 4/, Pb/sub 5/(VO/sub 4/)/sub 2/SiO/sub 4/ (all with apatite structure) are also measured and briefly discussed. The X-ray, spectroscopic and analytical investigation of the lead vanadates precipitated from solutions, shows that in this cases mixed crystals of complicated nature, with the apatite structure, are obtained.

Comparative study for the removal of Sr2+ and Pb2+ from waste solutions using synthetic and natural cow bone apatite

International Nuclear Information System (INIS)

Ezz El-Din, M.R.

2007-01-01

The aim of this study is to develop the cow bone derived apatite as a new sorbent for Sr 2+ and Pb 2+ ions from their aqueous waste solutions. In this respect, four different types of apatite (Ca 10 (PO 4 )6(OH) 2 ) were investigated. The first was natural cow bone apatite (raw bone). The second was cow bone derived apatite after treatment at 700 degree C. The third was synthetic apatite and the last was commercial apatite supplied from Bio Rad company, USA. Removal of Sr 2+ and Pb 2+ by the studied samples was investigated using batch experiments. The different parameters affecting sorption process such as contact time, metal ion concentration and hydrogen ion concentration of the aqueous phase were studied. Desorption of the investigated ions from the loaded samples was also studied. The results obtained showed that the raw cow bone was more effective than the other investigated HAP for adsorbing both Sr 2+ and Pb 2+ ions since the removal percentage of Sr 2+ and Pb 2+ by natural cow bone apatite were 85% and 98%, respectively, while the removal of Sr 2+ and Pb 2+ by the synthetic apatite were 71% and 62%, respectively. From the obtained data, it can be concluded that the natural (raw) cow bone apatite can be used as an ion exchanger for removal of some radioactive elements that may present in radioactive waste solutions as well as it could be considered as a new competitor of the other natural absorbents. Therefore, it is recommended that the natural cow bone apatite could be used for removal of both Sr 2+ and Pb 2+ from radioactive waste solutions as well as other wastewater

Nucleation and growth of apatite on NaOH-treated PEEK, HDPE and UHMWPE for artificial cornea materials.

Science.gov (United States)

Pino, M; Stingelin, N; Tanner, K E

2008-11-01

The skirt of an artificial cornea must integrate the implant to the host sclera, a major failure of present devices. Thus, it is highly desirable to encourage the metabolic activity of the cornea by using more bioactive, flexible skirt materials. Here we describe attempts to increase the bioactivity of polyether ether ketone (PEEK), high-density polyethylene (HDPE) and ultra-high molecular weight polyethylene (UHMWPE) films. The effectiveness of different strength NaOH pre-treatments to initiate apatite deposition on PEEK, HDPE and UHMWPE is investigated. We find that exposure of PEEK, HDPE and UHMWPE films to NaOH solutions induces the formation of potential nuclei for apatite (calcium phosphate), from which the growth of an apatite coating is stimulated when subsequently immersing the polymer films in 1.5 strength Simulated Body Fluid (SBF). As immersion time in SBF increases, further nucleation and growth produces a thicker and more compact apatite coating that can be expected to be highly bioactive. Interestingly, the apatite growth is found to also be dependent on both the concentration of NaOH solution and the structure of the polymer surface.

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

Energy Technology Data Exchange (ETDEWEB)

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.

Bioactive coatings on Portland cement substrates: Surface precipitation of apatite-like crystals

International Nuclear Information System (INIS)

Gallego, Daniel; Higuita, Natalia; Garcia, Felipe; Ferrell, Nicholas; Hansford, Derek J.

2008-01-01

We report a method for depositing bioactive coatings onto cement materials for bone tissue engineering applications. White Portland cement substrates were hydrated under a 20% CO 2 atmosphere, allowing the formation of CaCO 3 . The substrates were incubated in a calcium phosphate solution for 1, 3, and 6 days (CPI, CPII, and CPIII respectively) at 37 deg. C to induce the formation of carbonated apatite. Cement controls were prepared and hydrated with and without CO 2 atmosphere (C+ and C- respectively). The presence of apatite-like crystals was verified by Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopy (EDS). The substrate cytocompatibility was evaluated via SEM after 24 hour cell cultures. SEM revealed the presence Ca(OH) 2 on C-, and CaCO 3 on C+. Apatite-like crystals were detected only on CPIII, confirmed by phosphorus EDS peaks only for CPIII. Cells attached and proliferated similarly well on all the substrates except C-. These results prove the feasibility of obtaining biocompatible and bioactive coatings on Portland cement for bone tissue engineering applications

Treatability study operational testing program and implementation plan for the Gunite and Associated Tanks at Oak Ridge National Laboratory, Oak Ridge, Tennessee

International Nuclear Information System (INIS)

1996-03-01

This Treatability Study (TS) Operational Testing Program and Implementation Plan identifies operational testing to be performed to: (1) Demonstrate the technical feasibility of methods proposed for the removal of radiochemical sludge heels from the underground storage tanks located at Oak Ridge National Laboratory (ORNL), known as the Gunite and Associated Tanks (GAAT) Operable Unit (OU). (The bulk of the radiochemical waste, which was previously stored in the tanks, was removed during the 1980s, and only a sludge heel remains.) (2) Reduce the uncertainty in meeting the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) requirements for the GAAT OU. (3) Minimize the overall costs to accomplish the first two objectives. An initial Feasibility Study (FS) effort identified uncertainties in the evaluation of various alternatives for addressing the remediation of the GAAT OU. To support future decision making, the US. Department of Energy is performing a TS to identify cost-effective remediation approaches for the GAAT OU by providing information to reduce cost and technical uncertainty and better define acceptable remediation strategies. The testing activities will be initially conducted in a nonradioactive environment at the Tanks Technology Cold Test Facility (TTCTF) at ORNL. This will permit the design and initial performance testing and training activities to be completed while minimizing the risk, employee exposure, and costs associated with the testing effort. The component design and functional testing and initial system performance testing will be completed in the TTCTF. After the component and initial system performance testing have been completed, the operations testing will continue in the North Tank Farm (NTF). This testing has an associated higher cost and risk, but is necessary to provide results for actual waste heel removal

Apatite Formation and Biocompatibility of a Low Young’s Modulus Ti-Nb-Sn Alloy Treated with Anodic Oxidation and Hot Water

Science.gov (United States)

Tanaka, Hidetatsu; Mori, Yu; Noro, Atsushi; Kogure, Atsushi; Kamimura, Masayuki; Yamada, Norikazu; Hanada, Shuji; Masahashi, Naoya; Itoi, Eiji

2016-01-01

Ti-6Al-4V alloy is widely prevalent as a material for orthopaedic implants because of its good corrosion resistance and biocompatibility. However, the discrepancy in Young’s modulus between metal prosthesis and human cortical bone sometimes induces clinical problems, thigh pain and bone atrophy due to stress shielding. We designed a Ti-Nb-Sn alloy with a low Young’s modulus to address problems of stress disproportion. In this study, we assessed effects of anodic oxidation with or without hot water treatment on the bone-bonding characteristics of a Ti-Nb-Sn alloy. We examined surface analyses and apatite formation by SEM micrographs, XPS and XRD analyses. We also evaluated biocompatibility in experimental animal models by measuring failure loads with a pull-out test and by quantitative histomorphometric analyses. By SEM, abundant apatite formation was observed on the surface of Ti-Nb-Sn alloy discs treated with anodic oxidation and hot water after incubation in Hank’s solution. A strong peak of apatite formation was detected on the surface using XRD analyses. XPS analysis revealed an increase of the H2O fraction in O 1s XPS. Results of the pull-out test showed that the failure loads of Ti-Nb-Sn alloy rods treated with anodic oxidation and hot water was greater than those of untreated rods. Quantitative histomorphometric analyses indicated that anodic oxidation and hot water treatment induced higher new bone formation around the rods. Our findings indicate that Ti-Nb-Sn alloy treated with anodic oxidation and hot water showed greater capacity for apatite formation, stronger bone bonding and higher biocompatibility for osteosynthesis. Ti-Nb-Sn alloy treated with anodic oxidation and hot water treatment is a promising material for orthopaedic implants enabling higher osteosynthesis and lower stress disproportion. PMID:26914329

Beta transmutations in apatites with ferric iron as an electron acceptor - implication for nuclear waste form development.

Science.gov (United States)

Yao, Ge; Zhang, Zelong; Wang, Jianwei

2017-09-27

Apatite-structured materials have been considered for the immobilization of a number of fission products from reprocessing nuclear fuel because of their chemical durability as well as compositional and structural flexibility. It is hypothesized that the effect of beta decay on the stability can be mitigated by introducing an appropriate electron acceptor at the neighboring sites in the structure. The decay series 137 Cs → 137 Ba and 90 Sr → 90 Y → 90 Zr were investigated using a spin-polarized DFT approach to test the hypothesis. Apatites with compositions of Ca 10 (PO 4 ) 6 F 2 and Ca 4 Y 6 (SiO 4 ) 6 F 2 were selected as model systems for the incorporation of radionuclides Cs and Sr, respectively. Ferric iron was introduced in the structure as an electron acceptor. Electron density of states, crystal and defect structures, and energies before and after beta decay were calculated. The calculated electron density of states suggests that the extra electron is localized at the ferric iron, which changes its oxidation state and becomes ferrous iron. The crystal and defect structures were analyzed based on the volume, lattice parameters, radial distribution functions, metal cation to coordinating oxygen distances, and the metaprism twist angle of the apatite crystal structure. The results show that there are minor changes in the crystal and defect structures of CsFeCa 8 (PO 4 ) 6 F 2 with Cs + and Fe 3+ substitutions undergoing the Cs → Ba transmutation, and of Ca 3 SrY 4 Fe 2 (SiO 4 ) 6 F 2 with Sr 2+ and Fe 3+ substitutions undergoing the Sr → Y → Zr transmutations. The last decay change, from Y 3+ → Zr 4+ , causes relatively larger changes in the local defect structure around Zr involving the coordination environment but the change is not significant to the crystal structure. The results on calculated cohesive energy suggest that the transmutations Cs + → Ba 2+ and Sr 2+ → Y 3+ → Zr 4+ in both apatite compositions are energetically favorable

Thermal annealing of fission tracks in fluorapatite, chlorapatite, manganoanapatite, and Durango apatite: experimental results

International Nuclear Information System (INIS)

Ravenhurst, C.E.; Roden-Tice, M.K.; Miller, D.S.

2003-01-01

It is well known that the optically measured lengths of fission tracks in apatite crystals are a function of etching conditions, crystallographic orientation of the track, composition of the crystal, and the state of thermal annealing. In this study we standardize etching conditions and optimize track length measurability by etching until etch pits formed at the surface of each apatite crystal reached widths of about 0.74 μm. Etching times using 5M HNO 3 at 21 o C were 31 s for Otter Lake, Quebec, fluorapatite; 47 s for Durango, Mexico, apatite; 33 s for Portland, Connecticut, manganoanapatite; and 11 s for Bamle, Norway, chlorapatite. An etching experiment using two etchant strengths (5M and 1.6M HNO 3 ) revealed that, despite significant differences in etch pit shape, fission-track length anisotropy with respect to crystallographic orientation of the tracks is not a chemical etching effect. A series of 227 constant-temperature annealing experiments were carried out on nuclear reactor induced tracks in oriented slices of the apatites. After etching, crystallographic orientations of tracks were measured along with their lengths. The 200-300 track lengths measured for each slice were ellipse-fitted to give the major (c crystallographic direction) and minor (a crystallographic direction) semi-axes used to calculate equivalent isotropic lengths. The equivalent isotropic length is more useful than mean length for thermal history analysis because the variation caused by anisotropy has been removed. Using normalized etching procedures and equivalent isotropic length data, we found that the fluorapatite anneals most readily, followed by Durango apatite, manganoanapatite, and lastly chlorapatite. (author)

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

International Nuclear Information System (INIS)

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

2011-01-01

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 3 PO 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.

Cationic polymers in water treatment: Part 1: Treatability of water with cationic polymers

Czech Academy of Sciences Publication Activity Database

Polasek, P.; Mutl, Silvestr

2002-01-01

Roč. 28, č. 1 (2002), s. 69-82 ISSN 0378-4738 R&D Projects: GA AV ČR KSK2067107 Keywords : cationic polymers * treatability * water quality Subject RIV: BK - Fluid Dynamics Impact factor: 0.481, year: 2002

Removal of cadmium, copper, nickel, cobalt and mercury from water by Apatite II{sup TM}: Column experiments

Energy Technology Data Exchange (ETDEWEB)

Oliva, Josep [Department of Mining Engineering and Natural Resou-rces, Universitat Politecnica de Catalunya, Bases de Manresa 61-73, 08242 Manresa, Catalonia (Spain); De Pablo, Joan [Department of Chemical Engineering, Universitat Politecnica de Catalunya, Diagonal 647, 08028 Barcelona, Catalonia (Spain); Cortina, Jose-Luis, E-mail: jose.luis.cortina@upc.edu [Department of Chemical Engineering, Universitat Politecnica de Catalunya, Diagonal 647, 08028 Barcelona, Catalonia (Spain); Water Technology Center, CETaqua, Paseo de los Tilos 3, 08034 Barcelona, Catalonia (Spain); Cama, Jordi; Ayora, Carlos [Institute of Environmental Assessment and Water Research, IDAEA, CSIC, Jordi Girona 18, 08034 Barcelona, Catalonia (Spain)

2011-10-30

Highlights: {yields} The efficiency of Apatite II{sup TM} increases as the acidity decreases, then the application of apatite-based materials for metal removal treatments should be restricted to slightly acid to neutral waters. {yields} Because of the preferred process of using phosphate ions to form metal-phosphate precipitates, the mixture with other sources of alkalinity, such as limestone, is proposed to extend the duration of Apatite II{sup TM}. {yields} Compared with other reactive materials such as limestone and caustic magnesia that exhibit a reduction of porosity Apatite II{sup TM} showed stable hydraulic performance. {yields} The extrapolation of the column durabilities to a 1-m-thick passive treatment suggests that the Apatite II{sup TM} filling can be active between 5 and 10 years for an inflow pH exceeding 5. - Abstract: Apatite II{sup TM}, a biogenic hydroxyapatite, was evaluated as a reactive material for heavy metal (Cd, Cu, Co, Ni and Hg) removal in passive treatments. Apatite II{sup TM} reacts with acid water by releasing phosphates that increase the pH up to 6.5-7.5, complexing and inducing metals to precipitate as metal phosphates. The evolution of the solution concentration of calcium, phosphate and metals together with SEM-EDS and XRD examinations were used to identify the retention mechanisms. SEM observation shows low-crystalline precipitate layers composed of P, O and M. Only in the case of Hg and Co were small amounts of crystalline phases detected. Solubility data values were used to predict the measured column experiment values and to support the removal process based on the dissolution of hydroxyapatite, the formation of metal-phosphate species in solution and the precipitation of metal phosphate. Cd{sub 5}(PO{sub 4}){sub 3}OH(s), Cu{sub 2}(PO{sub 4})OH(s), Ni{sub 3}(PO{sub 4}){sub 2}(s), Co{sub 3}(PO{sub 4}){sub 2}8H{sub 2}O(s) and Hg{sub 3}(PO{sub 4}){sub 2}(s) are proposed as the possible mineral phases responsible for the removal

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

Science.gov (United States)

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

Biomimetic growth and substrate dependent mechanical properties of bone like apatite nucleated on Ti and magnetron sputtered TiO2 nanostructure

Science.gov (United States)

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.

Biomimetic growth and substrate dependent mechanical properties of bone like apatite nucleated on Ti and magnetron sputtered TiO2 nanostructure

International Nuclear Information System (INIS)

Sarma, Bimal K; Das, Apurba; Barman, Pintu; Pal, Arup R

2016-01-01

This report presents findings on biomimetic growth of hydroxyapatite (HAp) nanocrystals on Ti and sputtered TiO 2 substrates. The possibility of TiO 2 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-TiO 2 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-TiO 2 /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-TiO 2 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. (paper)

Experimental Plan: 300 Area Treatability Test: In Situ Treatment of the Vadose Zone and Smear Zone Uranium Contamination by Polyphosphate Infiltration

International Nuclear Information System (INIS)

Wellman, Dawn M.; Pierce, Eric M.; Oostrom, Mart; Fruchter, Jonathan S.

2007-01-01

The overall objectives of the treatability test is to evaluate and optimize polyphosphate remediation technology for infiltration either from ground surface, or some depth of excavation, providing direct stabilization of uranium within the deep vadose and capillary fringe above the 300 Area aquifer. Expected result from this experimental plan is a data package that includes: (1) quantification of the retardation of polyphosphate, (2) the rate of degradation and the retardation of degradation products as a function of water content, (3) an understanding of the mechanism of autunite formation via the reaction of solid phase calcite-bound uranium and aqueous polyphosphate remediation technology, (4) an understanding of the transformation mechanism, identity of secondary phases, and the kinetics of the reaction between uranyl-carbonate and silicate minerals with the polyphosphate remedy under solubility-limiting conditions, (5) quantification of the extent and rate of uranium released and immobilized based on the infiltration rate of the polyphosphate remedy and the effect of and periodic wet-dry cycling on the efficacy of polyphosphate remediation for uranium in the vadose zone and capillary fringe, and (6) quantification of reliable equilibrium solubility values for autunite under hydraulically unsaturated conditions allowing accurate prediction of the long-term stability of autunite. Moreover, results of intermediate scale testing will quantify the transport of polyphosphate and degradation products, and yield degradation rates, at a scale that is bridging the gap between the small-scale UFA studies and the field scale. These results will be used to test and verify a site-specific, variable saturation, reactive transport model and to aid in the design of a pilot-scale field test of this technology. In particular, the infiltration approach and monitoring strategy of the pilot test would be primarily based on results from intermediate-scale testing. Results from this

Calcium phosphate composite cements based on simple mixture of brushite and apatite phases

Science.gov (United States)

Egorov, A. A.; Fedotov, A. Yu; Pereloma, I. S.; Teterina, A. Yu; Sergeeva, N. S.; Sviridova, I. K.; Kirsanova, V. A.; Akhmedova, S. A.; Nesterova, A. V.; Reshetov, I. V.; Barinov, S. M.; Komlev, V. S.

2018-04-01

The composite cements based on simple mixtures brishite and apatite with ratio 70/30, 50/50, 30/70 were developed. The processes of phase formation, microstructure and mechanical properties were studied. The kinetics of degradation in simulated body fluid depending on the microstructure and the materials phase composition was carried out. The biological test in vitro were performed using the MTT-test on the human fibroblast immortalized (hFB) cell line and the human osteosarcoma cell line MG-63. The materials didn’t have acute cytoxicity and possessed surface matrix properties. It was determined that the both line of cells actively proliferated, with viable cells values higher 20-60 % then control at all observation periods.

Framework 'interstitial' oxygen in La10(GeO4)5-(GeO5)O2 apatite electrolyte

International Nuclear Information System (INIS)

Pramana, S.S.; White, T.J.

2007-01-01

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. (orig.)

Cd2+ and Zn2+ sorption on apatite in the presence of EDTA and humic substance

Directory of Open Access Journals (Sweden)

Viipsi K.

2013-04-01

Full Text Available The sorption of Cd2+ and Zn2+ on hydroxyapatite [HAP- Ca10(PO46(OH2] and fluorapatite [FAP- Ca10( PO46(F2] with different specific surface area and stoichiometry was investigated in batch experiments in the pH range 4 to 11 (25 ◦C; 0.1 M KNO3. The impact of different conditions was concerned: solution pH, the presence of complexing ligands (EDTA and humic substance and competing metal ions, as well as reaction kinetic and equilibrium conditions. To evaluate the reversibility of Cd2+ sorption onto HAP, desorption characteristics in water, Ca, EDTA, and HUM-solutions were determined. Additionally to solution analysis the surface composition of solid phases was analysed by X-Ray Photoelectron Spectroscopy XPS. The information from the chemical analyses was used to design an equilibration model that takes into account dissolution, surface potential, solution and surface complexation, as well as possible phase transformations. It was revealed that apatites effectively sorb Cd2+ and Zn2+ by ion exchange reactions on surface by formation of new surface phases. Using XPS the formation of a Me-enriched HAP surface was found, which was interpreted as the formation of a solid solution with the general formula: Ca8.4-xMex(HPO41.6(PO44.4(OH0.4. In a binary solution (Cd+Zn the competition of metals reduced individual sorbed amount compared with the single component solutions but the total adsorption maximum was approximately constant. The presence of EDTA reduces the metal sorption on apatite due to [CdEDTA]2- and [ZnEDTA]2- complexes and increases apatite solubility due to [CaEDTA]2- complex formation. The dissolved humic substance was bound on apatite in suspensions but the amount of Cd2+ bound was not changed. The results showed that the solution pH and the presence of complexing ligands have a significant effect on heavy metal sorption on apatite and must be considered if apatites are used as remediation agent. The proposed model can be used to predict

Work plan for the treatability study for PCB dehalogenation by Agent 313 in Waste Area Grouping 11 at Oak Ridge National Laboratory, Oak Ridge, Tennessee

International Nuclear Information System (INIS)

1994-08-01

This work Plan describes the treatability study for Polychlorinated biphenyl (PCB) debalogenation by Agent 313 (a registered trademark of the A.L. Sandpiper Corporation of Columbus, ohio) to be conducted at Waste Area Grouping (WAG) 11 on the Oak Ridge Reservation. The study will be conducted at WAG 11 as a result of the contamination of several small areas of soil by leaking capacitors. The primary purpose of this treatability study is to demonstrate the effectiveness of Agent 313 in remediating PCB-contaminated soil. However, the WAG 11 soils to be treated may also contain radionuclides and metals. In addition to providing the procedures to be followed during the treatability study, the work plan briefly describes the project background and technology, lists applicable or relevant and appropriate requirements for the project, and delineates project goals and objectives. This document also follows the general suggested outline for treatability study work plans shown in the 1992 report Guide for conducting Treatability Studies Under CERCLA: Final, EPA;540/R-92-071a, published by the US Environmental Protection Agency

Evaluation of the Ca ion release, pH and surface apatite formation of a prototype tricalcium silicate cement.

Science.gov (United States)

Yamamoto, S; Han, L; Noiri, Y; Okiji, T

2017-12-01

To evaluate the Ca 2+ -releasing, alkalizing and apatite-like surface precipitate-forming abilities of a prototype tricalcium silicate cement, which was mainly composed of synthetically prepared tricalcium silicate and zirconium oxide radiopacifier. The prototype tricalcium silicate cement, white ProRoot MTA (WMTA) and TheraCal LC (a light-cured resin-modified calcium silicate-filled material) were examined. The chemical compositions were analysed with a wavelength-dispersive X-ray spectroscopy electron probe microanalyser with an image observation function (SEM-EPMA). The pH and Ca 2+ concentrations of water in which the set materials had been immersed were measured, and the latter was assessed with the EDTA titration method. The surface precipitates formed on the materials immersed in phosphate-buffered saline (PBS) were analysed with SEM-EPMA and X-ray diffraction (XRD). Kruskal-Wallis tests followed by Mann-Whitney U-test with Bonferroni correction were used for statistical analysis (α = 0.05). The prototype cement contained Ca, Si and Zr as major elemental constituents, whereas it did not contain some metal elements that were detected in the other materials. The Ca 2+ concentrations and pH of the immersion water samples exhibited the following order: WMTA = prototype cement > TheraCal LC (P prototype cement and WMTA. The prototype tricalcium silicate cement exhibited similar Ca 2+ -releasing, alkalizing and apatite-like precipitate-forming abilities to WMTA. The Ca 2+ -releasing, alkalizing and apatite-like precipitate-forming abilities of TheraCal LC were lower than those of the other materials. © 2016 International Endodontic Journal. Published by John Wiley & Sons Ltd.

Treatability study for removal of leachable mercury in crushed fluorescent lamps

International Nuclear Information System (INIS)

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

Treatability study for removal of leachable mercury in crushed fluorescent lamps

Energy Technology Data Exchange (ETDEWEB)

Bostick, W.D.; Beck, D.E.; Bowser, K.T. [and others

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.

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

Energy Technology Data Exchange (ETDEWEB)

Wei Jie [Center for Biomedical Materials and Tissue Engineering, Academy for Advanced Inter-disciplinary Studies, Peking University, Beijing 100871 (China); Key Laboratory for Ultrafine Materials of Ministry of Education, East China University of Science and Technology, Shanghai 200237 (China); Wang Jiecheng; Liu Xiaochen [Center for Biomedical Materials and Tissue Engineering, Academy for Advanced Inter-disciplinary Studies, Peking University, Beijing 100871 (China); Ma Jian [Hospital of Stomatology, Tongji University, Shanghai 200072 (China); Liu Changsheng [Key Laboratory for Ultrafine Materials of Ministry of Education, East China University of Science and Technology, Shanghai 200237 (China); Fang Jing, E-mail: biomater2006@yahoo.com.cn [Center for Biomedical Materials and Tissue Engineering, Academy for Advanced Inter-disciplinary Studies, Peking University, Beijing 100871 (China); Wei Shicheng, E-mail: nic7505@263.net [Center for Biomedical Materials and Tissue Engineering, Academy for Advanced Inter-disciplinary Studies, Peking University, Beijing 100871 (China) and School and Hospital of Stomatology, Peking University, Beijing 100081 (China)

2011-06-15

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{sub 3}PO{sub 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.

Calibration of the Fluorine, Chlorine and Hydrogen Content of Apatites With the ChemCam LIBS Instrument

Science.gov (United States)

Meslin, P.-Y.; Cicutto, L.; Forni, O.; Drouet, C.; Rapin, W.; Nachon, M.; Cousin, A.; Blank, J. G.; McCubbin, F. M.; Gasnault, O.;

Characterization and potential application of pataua vegetable oil in apatite flotation

International Nuclear Information System (INIS)

Oliveira, P.S. de; Mansur, H.S.; Peres, A.E.C.

2016-01-01

The present research characterizes the Pataua palm (Oenocarpus bataua) oil regarding to its fatty acids profile and acidity index, and evaluates its use for apatite flotation. The Pataua oil evaluated is unsaturated e predominantly composed of cis-9-octadecenoic acid (oleic acid). The mineral sample characterization revealed a material composed by a fluoroapatite deficient in fluorine, a possibly result of isomorphic substitution, and with quartz and monazite inclusions. The analysis of the mineral after reagent conditioning, by Fourier Transform Infrared Spectroscopy (FTIR), pointed to the presence of characteristic bands of carbon chains and carboxylate group, suggesting the collector adsorption through the mechanisms of chemisorption and insoluble calcium salts precipitation. Thus, it is proposed the Pataua oil potential use in flotation systems aiming apatite recovery. (author)

Apatite fission track evidence on the uplifting of eastern Kunlun mountains

International Nuclear Information System (INIS)

Yuang Wanming; Dong Jinquan; Tang Yunhui; Wang Shicheng

2004-01-01

A series of samples were collected from about south-north section through Buqingshan and Dulan, eastern Kunlun mountains, China. The 41 apatite fission track ages (FTA) of these samples lie between 25.2 and 130.4 Ma, all of the apatite fission track ages are significantly younger than the host rocks. There are similar evolution trends for Middle-Kunlun zone and North-Kunlun zone, i.e. the FTA becomes less with slow increase of elevations and their uplifting rates are about 2.22 m/Ma. Differently, the FTA in South-Kunlun zone positively correlates to elevation, decreasing 11 m/Ma. It may be shown that South-Kunlun fault play a different and/or more important role on incontinent evolution than Middle-Kunlun fault. (author)

The increase of apatite layer formation by the poly(3-hydroxybutyrate) surface modification of hydroxyapatite and β-tricalcium phosphate

Energy Technology Data Exchange (ETDEWEB)

Szubert, M., E-mail: mm.szubert@gmail.com [Faculty of Chemical Technology, Poznan University of Technology, Poznan (Poland); Adamska, K. [Faculty of Chemical Technology, Poznan University of Technology, Poznan (Poland); Szybowicz, M. [Faculty of Technical Physics, Poznan University of Technology, Poznan (Poland); Jesionowski, T. [Faculty of Chemical Technology, Poznan University of Technology, Poznan (Poland); Buchwald, T. [Faculty of Technical Physics, Poznan University of Technology, Poznan (Poland); Voelkel, A. [Faculty of Chemical Technology, Poznan University of Technology, Poznan (Poland)

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. - Highlights: • Surface modification of HA and β-TCP was performed by PHB grafting. • The growth of apatite layer on materials was examined in simulated body fluid (SBF). • The bioactivity of obtained materials was proved. • The replacement of SBF solution plays an important role in the process of apatite formation.

The increase of apatite layer formation by the poly(3-hydroxybutyrate) surface modification of hydroxyapatite and β-tricalcium phosphate

International Nuclear Information System (INIS)

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. - Highlights: • Surface modification of HA and β-TCP was performed by PHB grafting. • The growth of apatite layer on materials was examined in simulated body fluid (SBF). • The bioactivity of obtained materials was proved. • The replacement of SBF solution plays an important role in the process of apatite formation

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

International Nuclear Information System (INIS)

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

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 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

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

Energy Technology Data Exchange (ETDEWEB)

Spalding, B.P.; Naney, M.T.; Cline, S.R.; Bogle, M.A. [Oak Ridge National Lab., TN (United States). Environmental Sciences Div.; Tixier, J.S. [Pacific Northwest National Lab., Richland, WA (United States)

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.

Formation of apatite layers on modified canasite glass-ceramics in simulated body fluid.

Science.gov (United States)

Miller, C A; Kokubo, T; Reaney, I M; Hatton, P V; James, P F

2002-03-05

Canasite glass-ceramics were modified by either increasing the concentration of calcium in the glass, or by the addition of P2O5. Samples of these novel materials were placed in simulated body fluid (SBF), along with a control material (commercial canasite), for periods ranging from 12 h to 28 days. After immersion, surface analysis was performed using thin film X-ray diffraction, Fourier transform infrared reflection spectroscopy, and scanning electron microscopy equipped with energy dispersive X-ray detectors. The concentrations of sodium, potassium, calcium, silicon, and phosphorus in the SBF solution were measured using inductively coupled plasma emission spectroscopy. No apatite was detected on the surface of commercial canasite, even after 28 days of immersion in SBF. A crystalline apatite layer was formed on the surface of a P2O5-containing canasite after 5 days, and after 3 days for calcium-enriched canasite. Ion release data suggested that the mechanism for apatite deposition was different for P2O5 and non-P2O5-containing glass-ceramics. Copyright 2001 John Wiley & Sons, Inc.

On the reproducibility of apatite fission-track plateau-age dating

International Nuclear Information System (INIS)

Poupeau, G.; Baitelli, R.; Berbert, M.; Fonseca, A.

1985-01-01

Duplicate measurements as well as published data show that plateau-age measurements on apatites have a reproducibility - when made in optical microscopy - generally better than +- 5%, which may be accounted for by statistical errors on track density measurement. (Author) [pt

Syntheses and characterizations of rare earth doped phospho-silicated apatites: application to nuclear waste confinement

International Nuclear Information System (INIS)

Boyer, Laurent

1998-01-01

Apatite matrices have been developed for the conditioning of actinides from spent fuels of PWR reactors. Silicated apatites (britholites) containing actinides and lanthanides have been discovered in the natural environment. Synthetic analogues of these britholites can be obtained by solid-solid reaction at high temperature. The compounds of the solid solution of fluorinated britholites are synthesized by the double substitution of (Ca 2+ , PO 4 3- ) by (Ln 3+ , SiO 4 4- ). Trivalent lanthanides are chemical analogues of trivalent actinides. The synthesis was performed with La, Nd and Eu. This study allows to demonstrate that the chemical immobilization comes from the fixation of rare earths at the atomic scale, thanks to their participation to the mineral structure. In part 1, the criteria for the formulation of a matrix for the conditioning of separate radionuclides are given. The structure and the different methods of apatite preparation are shown. Part 2 treats of the study of the solid solution, of the elaboration of the Ca 9 Nd 1 (SiO 4 ) 5 F 2 ceramic and of its physico chemical characterization. The last part deals with the localization of rare earths in the apatite structure, determined by europium luminescence and X-ray diffraction on monocrystal. (J.S.) [fr

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

Science.gov (United States)

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. Copyright © 2013 Elsevier B.V. All rights reserved.

Genesis of rare-metal pegmatites and alkaline apatite-fluorite rocks of Burpala massi, Northern Baikal folded zone

Science.gov (United States)

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

Study of retention properties of fluoro-apatite carbonate relative to Ni(II), Am(III) and Th(IV)

International Nuclear Information System (INIS)

Perrone, Jane

1999-01-01

Apatite minerals and particularly the carbonated species (francolites), are characterized by their chemical and geological stability and also by their capacity to retain durably a large number of elements. Therefore, they should be able to improve the retention properties of the engineered barriers of a deep geological nuclear waste repository. But there is a wide variety of francolites, so we focused our study on a synthetic carbonate fluoro-apatite of formula: Ca 10 (PO 4 ) 5 (CO 3 )(F,OH) 3 and on a natural apatite. We first studied their solubility which is an important criterion for the choice of the materials. A particular attention was also paid to the determination of their surface characteristics and to the study of the radionuclide/solution interactions. Sorption experiments have been performed for the three radionuclides and the influence of various parameters has been investigated. The modelling of the sorption isotherms with surface complexation models leads us to estimate the values of the constants associated to the equilibria under consideration. We have also demonstrated that the phosphate ions of the solution participate to the immobilization of americium as the AmPO 4 ,xH 2 O compound. Both apatites show high retention levels for the actinides: the sorption is quite total over all the pH range studied and the Kd values are close to 10 4 m 3 kg -1 . Consequently, the use of apatites could be considered as a specific solution for the immobilisation of heavy elements, specially actinides. Moreover, the results indicate that high amounts of carbonates and impurities do not alter the retention properties of francolites. This bears out the feasibility of the use of natural apatites as additives for the engineered barrier materials. (author)

Waste management plan for Phase II of the Bear Creek Valley treatability study Oak Ridge Y-12 Plant, Oak Ridge, Tennessee

International Nuclear Information System (INIS)

1997-05-01

This Waste Management Plant (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 denitrifying capacity and metal uptake capacity of a wetland system; and the long-term denitrifying capacity and metal uptake capacity of algal mats. 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: (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

Visualization of structural organization of ventral membranes of sheared-open resorbing osteoclasts attached to apatite pellets.

Science.gov (United States)

Akisaka, Toshitaka; Yoshida, Atsushi

2015-05-01

Osteoclasts are highly polarized cells from both morphological and functional points of view. Using quick-freeze, rotary-replication methods combined with cell-shearing, we clarified the variability of cytoplasmic surface of the polarized membranes of osteoclasts seeded on apatite. As to the organization of actin filaments and clathrin sheets, we confirmed almost the same ventral membrane specializations of osteoclasts on apatite as seen on glass plates. The organized actin filaments and membrane-associated particles supported the ruffled border membranes. Inside the actin sealing zone, membrane specializations were not always occupied with the ruffled border but also with other types of membranes. Some osteoclasts formed an actin ring but lacked the ruffled border projections. We report a unique and distinctive membrane modification of apatite-attached osteoclasts, i.e., the presence of dense aggregates of membrane-associated particles and related structures not found in the osteoclasts seeded on glass plates. Actin filament polarity in the podosomes was determined by decoration with myosin S1. The actin filament polarity within podosome appears to be oriented predominantly with its barbed ends toward the core, whereas the interconnecting F-actin appears to be mixed oriented. Two different types of clathrin plaques displayed different distributions: clathrin-dependent endocytosis was observed in the ruffled border regions, whereas flat clathrin sheets were found in the leading edge of lamellipodia and near podosomes. The clathrin sheets adhered to the apatite surface tightly on the ventral membranes overlaying the resorption lacunae. All these membrane specializations as mentioned above may indicate the functional variability of osteoclasts seeded on apatite.

Hanford 100N Area Apatite Emplacement: Laboratory Results of Ca-Citrate-PO4 Solution Injection and Sr-90 Immobilization in 100N Sediments

Energy Technology Data Exchange (ETDEWEB)

Szecsody, James E.; Burns, Carolyn A.; Moore, Robert C.; Fruchter, Jonathan S.; Vermeul, Vincent R.; Williams, Mark D.; Girvin, Donald C.; McKinley, James P.; Truex, Michael J.; Phillips, Jerry L.

2007-10-01

This report summarizes laboratory scale studies investigating the remediation of Sr-90 by Ca-citrate-PO4 solution injection/infiltration to support field injection activities in the Hanford 100N area. This study is focused on experimentally testing whether this remediation technology can be effective under field scale conditions to mitigate Sr-90 migration 100N area sediments into the Columbia River. Sr-90 is found primarily adsorbed to sediments by ion exchange (99% adsorbed, < 1% in groundwater) in the upper portion of the unconfined aquifer and lower vadose zone. Although primarily adsorbed, Sr-90 is still considered a high mobility risk as it is mobilized by seasonal river stage increases and by plumes of higher ionic strength relative to groundwater. This remediation technology relies upon the Ca-citrate-PO4 solution forming apatite precipitate [Ca6(PO4)10(OH)2], which incorporates some Sr-90 during initial precipitation and additionally slowly incorporates Sr-90 by solid phase substitution for Ca. Sr substitution occurs because Sr-apatite is thermodynamically more stable than Ca-apatite. Once the Sr-90 is in the apatite structure, Sr-90 will decay to Y-90 (29.1 y half-life) then Zr-90 (64.1 h half-life) without the potential for migration into the Columbia River. For this technology to be effective, sufficient apatite needs to be emplaced in sediments to incorporate Sr and Sr-90 for 300 years (~10 half-lives of Sr-90), and the rate of incorporation needs to exceed the natural groundwater flux rate of Sr in the 100N area. A primary objective of this study is to supply an injection sequence to deliver sufficient apatite into subsurface sediments that minimizes initial mobility of Sr-90, which occurs because the injection solution has a higher ionic strength compared to groundwater. This can be accomplished by sequential injections of low, then high concentration injection of Ca-citrate-PO4 solutions. Assessment of low concentration Ca-citrate-PO4, citrate-PO4

Solubility of apatite in H2O-NaCl and silicate-bearing solutions at 0.7-3.0 GPa, 800° C

Science.gov (United States)

Antignano, A.; Manning, C. E.

2004-12-01

Apatite is a major reservoir for the rare-earth elements (REE) in the earth's crust. However, little is known about its solubility in metamorphic fluids. We measured the solubility of apatite in H2O-NaCl and silicate bearing fluids at 800° C and 1.0-2.0 GPa using a piston-cylinder apparatus with NaCl-graphite furnaces. A single Durango fluor-apatite crystal was loaded into a 1.6 mm OD Pt inner capsule, which was crimped and then placed in a 3.5 OD Pt outer capsule with ultra pure H2O and NaCl or powdered albite. Solubility was determined by the weight loss of the apatite grain after 24 hrs. In the H2O-NaCl experiments, total dissolved solids (TDS) were initially below detection (0.4 millimolal) between XNaCl= 0 and XNaCl= 0.025. At XNaCl= 0.035, solubility was 3.3(0.2) millimolal (errors are 1s), and it increased to 57.5(0.4) millimolal at XNaCl= 0.526. Our results show that there is an enhancement in apatite solubility with increasing pressure in pure H2O. Solubility is initially below detection at bearing solutions. This probably explains textures in which monazite mantles apatite, which are common in granulite metamorphic terranes, such as the Kiirunavaara magnetite-apatite ore.

About the Genetic Mechanisms of Apatites: A Survey on the Methodological Approaches

Directory of Open Access Journals (Sweden)

Linda Pastero

2017-08-01

Full Text Available Apatites are properly considered as a strategic material owing to the broad range of their practical uses, primarily biomedical but chemical, pharmaceutical, environmental and geological as well. The apatite group of minerals has been the subject of a huge number of papers, mainly devoted to the mass crystallization of nanosized hydroxyapatite (or carboapatite as a scaffold for osteoinduction purposes. Many wet and dry methods of synthesis have been proposed. The products have been characterized using various techniques, from the transmission electron microscopy to many spectroscopic methods like IR and Raman. The experimental approach usually found in literature allows getting tailor made micro- and nano- crystals ready to be used in a wide variety of fields. Despite the wide interest in synthesis and characterization, little attention has been paid to the relationships between bulk structure and corresponding surfaces and to the role plaid by surfaces on the mechanisms involved during the early stages of growth of apatites. In order to improve the understanding of their structure and chemical variability, close attention will be focused on the structural complexity of hydroxyapatite (HAp, on the richness of its surfaces and their role in the interaction with the precursor phases, and in growth kinetics and morphology.

U-Th-He dating of apatite: A potential thermochronometer

International Nuclear Information System (INIS)

Zeitler, P.K.; Herczeg, A.L.; McDougall, I.; Honda, M.

1987-01-01

The authors found a gem quality crystal of Durango fluorapatite to have a 4 He content consistent with complete retention of radiogenic helium since its formation at about 31 Ma. Isothermal heating and step-heating analysis reveal 4 He loss to occur systematically by volume diffusion at low temperatures. The linear, low-temperature portion of the diffusion data yields an activation energy of 38.5 ± 8.1 kcal/mol and a frequency factor of 1n (D 0 /a 2 ) = 16.4 ± 2.8 sec -1 , corresponding to a closure temperature of 105 degree C ± 30 degree C (cooling rate 10 degree C/m.y.). It appears that U-Th-He dating of apatite might represent a useful new thermochronometer with a range similar to that of fission-track dating of apatite. From these results, they infer that a number of the too-young U-Th-He dates reported in the literature on minerals such as zircon and magnetite may in fact represent valuable records of the low-temperature thermal history of their host rocks

Atomistic modelling study of lanthanide incorporation in the crystal lattice of an apatite

International Nuclear Information System (INIS)

Louis-Achille, V.

1999-01-01

Studies of natural and synthetic apatites allow to propose such crystals as matrix for nuclear waste storage. The neodymium substituted britholite, Ca 9 Nd(PO 4 ) 5 (SiO 4 )F 2 . is a model for the trivalent actinide storage Neodymium can be substituted in two types of sites. The aim of this thesis is to compare the chemical nature of this two sites in fluoro-apatite Ca 9 (PO 4 ) 6 F 2 and then in britholite, using ab initio atomistic modeling. Two approaches are used: one considers the infinite crystals and the second considers clusters. The calculations of the electronic structure for both were performed using Kohn and Sham density functional theory in the local approximation. For solids, pseudopotentials were used, and wave functions are expanded in plane waves. For clusters, a frozen core approximation was used, and the wave functions are expanded in a linear combination of Slater type atomic orbitals. The pseudopotential is semi-relativistic for neodymium, and the Hamiltonian is scalar relativistic for the clusters. The validation of the solid approach is performed using two test cases: YPO 4 and ScPO 4 . Two numerical tools were developed to compute electronic deformation density map, and calculate partial density of stases. A full optimisation of the lattice parameters with a relaxation of the atomic coordinates leads to correct structural and thermodynamic properties for the fluoro-apatite, compared to experience. The electronic deformation density maps do not show any significant differences. between the two calcium sites. but Mulliken analysis on the solid and on the clusters point out the more ionic behavior of the calcium in site 2. A neodymium substituted britholite is then studied. Neodymium location only induces local modifications in; the crystalline structure and few changes in the formation enthalpy. The electronic study points out an increase of the covalent character the bonding involving neodymium compared with the one related to calcium

Comparison of hardenability calculation methods of the heat-treatable constructional steels

Energy Technology Data Exchange (ETDEWEB)

Dobrzanski, L.A.; Sitek, W. [Division of Tool Materials and Computer Techniques in Metal Science, Silesian Technical University, Gliwice (Poland)

1995-12-31

Evaluation has been made of the consistency of calculation of the hardenability curves of the selected heat-treatable alloyed constructional steels with the experimental data. The study has been conducted basing on the analysis of present state of knowledge on hardenability calculation employing the neural network methods. Several calculation examples and comparison of the consistency of calculation methods employed are included. (author). 35 refs, 2 figs, 3 tabs.

Inhibition of precipitation of carbonate apatite by trisodium citrate analysed in base of the formation of chemical complexes in growth solution

Energy Technology Data Exchange (ETDEWEB)

Prywer, Jolanta, E-mail: jolanta.prywer@p.lodz.pl [Institute of Physics, Lodz University of Technology, ul. Wólczańska 219, 93-005 Łódź (Poland); Olszynski, Marcin [Institute of Physics, Lodz University of Technology, ul. Wólczańska 219, 93-005 Łódź (Poland); Mielniczek-Brzóska, Ewa [Institute of Chemistry, Environment Protection and Biotechnology, Jan Długosz University of Częstochowa, ul. Armii Krajowej 13/15, 42-200 Częstochowa (Poland)

2015-11-15

Effect of trisodium citrate on the precipitation of carbonate apatite is studied. The experimental series are performed in the solution of artificial urine. The investigations are related to infectious urinary stones formation as carbonate apatite is one of the main components of this kind of stones. To mimic a real infection in urinary tract the aqueous ammonia solution was added to the solution of artificial urine. The spectrophotometric results demonstrate that trisodium citrate increases induction time with respect to carbonate apatite formation and decreases the efficiency of carbonate apatite precipitation. The inhibitory effect of trisodium citrate on the precipitation of carbonate apatite is explained in base of chemical speciation analysis. Such an analysis demonstrates that the inhibitory effect is mainly related with the fact that trisodium citrate binds Ca{sup 2+} ions and causes the formation of CaCit{sup −} and Ca{sub 10}(PO{sub 4}){sub 6}CO{sub 3} complexes. Trisodium citrate binds Ca{sup 2+} ions in the range of pH from 6 to 9.5 for which carbonate apatite is favored to be formed. - Highlights: • Trisodium citrate (TC) increases induction time of carbonate apatite (CA) formation. • TC decreases the efficiency of CA precipitation. • The inhibitory effect of TC is explained in base of chemical speciation analysis. • The inhibitory effect is mainly related with the fact that TC binds Ca{sup 2+} ions. • TC binds Ca{sup 2+} ions in the range of pH from 6 to 9.5 for which CA is formed.

In-situ Strontium Isotopes Analysis on Single Conodont Apatite by LA-MC-ICP-MS

Science.gov (United States)

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 CAIextinction 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., 2009 Earth Science J. of CUG [5] Zhao et al., 2013 GPC.

Study of the auto-irradiation effects in apatites structure materials; Etude des effets d'auto-irradiation dans des materiaux a structure apatitique

Energy Technology Data Exchange (ETDEWEB)

Soulet, St

2000-11-15

The incorporation of an actinide in a material puts it to the action of an alpha particle, of some MeV always followed by the recoil of the residual nucleus. This last ones, with an energy of about a hundred of keV produces the greatest part of the irradiation damages. The study of the natural analogues has allowed to identify the fluoro-apatites which have a high amount of phosphates groups, as potential actinides conditioning matrices. Former works, simulating the alpha decay in the monocrystalline phospho-calcic fluoro-apatite have revealed an exfoliation phenomenon and an annealing of the defects which are formed by the recoil nuclei by the helium ions. This work has shown that the exfoliation can not be produced on polycrystalline apatitic materials (phospho-calcic fluoro-apatite and fluoro-apatite with one silicate) probably on account of the removal of helium outside the grains and by the diffusion of helium inside the grain boundaries. On the other hand, these helium removal ways decrease the chemical resistance of the fluoro-apatite. In the same way, the dissolution velocity of the apatite is strongly increased above the damage threshold corresponding to the percolation of the isolated defects and especially in the case of total amorphization. Concerning the effect of the recoil and annealing nuclei by the alpha particles, an original study method including the use of a transmission electron microscope coupled with a ions implanter has been carried out. This device has allowed to make irradiations simulating the alpha decay and to follow in situ the evolution of polycrystalline samples disorder. It has been shown that for all the solid solution of phospho-silicated fluoro-apatites, the amorphization is produced directly in series. In the same way, on account of this technique, the efficiency of the annealing by alpha has been measured on different apatite compositions. The main result shows that the efficiency of the annealing by alpha in the fluoro-apatite

An EPR spectrum decomposition study of precipitated carbonated apatites (NCAP) dried at 25 deg C: adsorption of molecules from the atmosphere on the apatite powders

International Nuclear Information System (INIS)

Moens, P.D.W.; Callens, F.J.; Verbeeck, R.M.H.; Naessens, D.E.

1993-01-01

The effect of storage under ambient conditions on the Electron Paramagnetic Resonance (EPR) spectrum of X-irradiated sodium and carbonate containing synthetic apatites has been studied. A first series of samples was X-irradiated shortly after preparation and drying at 25 o C and investigated by means of EPR. The observed spectra were decomposed in terms of five theoretical curves representing an O - radical, two CO 3 - radicals (surface and bulk) and two CO 2 - radicals (surface and bulk). Afterwards, a second series of the same samples which was stored under ambient conditions for a long period, was also X-irradiated and examined with EPR. The same five radicals were found, but in different relative amounts. It appeared that the relative contributions of the two carbon containing surface radicals increased in comparison with the corresponding bulk radicals. This is explained by an adsorption of molecules from the atmosphere on the surface of the apatite powder. (author)

In vitro biomimetic deposition of apatite on alkaline and heat treated ...

Indian Academy of Sciences (India)

WINTEC

materials of choice for most dental and orthopedic appli- .... treatment on the surface of the substrate and the structure of the titanium substrate, gel layer and bone-like apatite coatings obtained were analysed by thin film X-ray dif-.

Bone apatite composition of necrotic trabecular bone in the femoral head of immature piglets.

Science.gov (United States)

Aruwajoye, Olumide O; Kim, Harry K W; Aswath, Pranesh B

2015-04-01

Ischemic osteonecrosis of the femoral head (IOFH) can lead to excessive resorption of the trabecular bone and collapse of the femoral head as a structure. A well-known mineral component to trabecular bone is hydroxyapatite, which can be present in many forms due to ionic substitution, thus altering chemical composition. Unfortunately, very little is known about the chemical changes to bone apatite following IOFH. We hypothesized that the apatite composition changes in necrotic bone possibly contribute to increased osteoclast resorption and structural collapse of the femoral head. The purpose of this study was to assess the macroscopic and local phosphate composition of actively resorbed necrotic trabecular bone to isolate differences between areas of increased osteoclast resorption and normal bone formation. A piglet model of IOFH was used. Scanning electron microscopy (SEM), histology, X-ray absorbance near edge structure (XANES), and Raman spectroscopy were performed on femoral heads to characterize normal and necrotic trabecular bone. Backscattered SEM, micro-computed tomography and histology showed deformity and active resorption of necrotic bone compared to normal. XANES and Raman spectroscopy obtained from actively resorbed necrotic bone and normal bone showed increased carbonate-to-phosphate content in the necrotic bone. The changes in the apatite composition due to carbonate substitution may play a role in the increased resorption of necrotic bone due to its increase in solubility. Indeed, a better understanding of the apatite composition of necrotic bone could shed light on osteoclast activity and potentially improve therapeutic treatments that target excessive resorption of bone.

Incorporation of cesium into phosphates of apatitic and rhabdophane lattices. Application to the conditioning of separated radionuclides

International Nuclear Information System (INIS)

Campayo, L.

2003-04-01

Two phosphate-based materials were investigated for cesium immobilization after its partitioning from spent nuclear fuel: apatites and rhabdophanes. The incorporation of cesium into the apatitic lattice creates steric stresses. These stresses induce the formation of secondary phases which are rapidly leached. The effectiveness of the cesium immobilization in this material is not therefore validated. A second phosphate CsCaNd(PO 4 ) 2 was consistently found at the end of the leach test and its properties were further characterized. The structure of CsCaNd(PO 4 ) 2 , which is rhabdophane-like, is made of large channels which enable the incorporation of the largest alkaline cations. The synthesis involves two intermediates: the monazite, NdPO 4 , and a soluble phosphate, CsCaPO 4 . The study of a rhabdophane with 10 wt.% of cesium reveals satisfactory intrinsic properties: a thermal stability up to 1100 C and a leach rate of 10 -2 g/(m 2 .d). The next step will be to improve the reaction yield. (author)

He, U, and Th Depth Profiling of Apatite and Zircon Using Laser Ablation Noble Gas Mass Spectrometry and SIMS

Science.gov (United States)

Monteleone, B. D.; van Soest, M. C.; Hodges, K. V.; Hervig, R.; Boyce, J. W.

2008-12-01

Conventional (U-Th)/He thermochronology utilizes single or multiple grain analyses of U- and Th-bearing minerals such as apatite and zircon and does not allow for assessment of spatial variation in concentration of He, U, or Th within individual crystals. As such, age calculation and interpretation require assumptions regarding 4He loss through alpha ejection, diffusive redistribution of 4He, and U and Th distribution as an initial condition for these processes. Although models have been developed to predict 4He diffusion parameters, correct for the effect of alpha ejection on calculated cooling ages, and account for the effect of U and Th zonation within apatite and zircon, measurements of 4He, U, and Th distribution have not been combined within a single crystal. We apply ArF excimer laser ablation, combined with noble gas mass spectrometry, to obtain depth profiles within apatite and zircon crystals in order to assess variations in 4He concentration with depth. Our initial results from pre-cut, pre-heated slabs of Durango apatite, each subjected to different T-t schedules, suggest a general agreement of 4He profiles with those predicted by theoretical diffusion models (Farley, 2000). Depth profiles through unpolished grains give reproducible alpha ejection profiles in Durango apatite that deviate from alpha ejection profiles predicted for ideal, homogenous crystals. SIMS depth profiling utilizes an O2 primary beam capable of sputtering tens of microns and measuring sub-micron resolution variation in [U], [Th], and [Sm]. Preliminary results suggest that sufficient [U] and [Th] zonation is present in Durango apatite to influence the form of the 4He alpha ejection profile. Future work will assess the influence of measured [U] and [Th] zonation on previously measured 4He depth profiles. Farley, K.A., 2000. Helium diffusion from apatite; general behavior as illustrated by Durango fluorapatite. J. Geophys. Res., B Solid Earth Planets 105 (2), 2903-2914.

Multiple Stage Ore Formation in the Chadormalu Iron Deposit, Bafq Metallogenic Province, Central Iran: Evidence from BSE Imaging and Apatite EPMA and LA-ICP-MS U-Pb Geochronology

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Hassan Heidarian

2018-02-01

Full Text Available The Chadormalu magnetite-apatite deposit in Bafq metallogenic province, Central Iran, is hosted in the late Precambrian-lower Cambrian volcano-sedimentary rocks with sodic, calcic, and potassic alterations characteristic of iron oxide copper-gold (IOCG and iron oxide-apatite (IOA ore systems. Apatite occurs as scattered irregular veinlets and disseminated grains, respectively, within and in the marginal parts of the main ore-body, as well as apatite-magnetite veins in altered wall rocks. Textural evidence (SEM-BSE images of these apatites shows primary bright, and secondary dark areas with inclusions of monazite/xenotime. The primary, monazite-free fluorapatite contains higher concentrations of Na, Si, S, and light rare earth elements (LREE. The apatite was altered by hydrothermal events that led to leaching of Na, Si, and REE + Y, and development of the dark apatite. The bright apatite yielded two U-Pb age populations, an older dominant age of 490 ± 21 Ma, similar to other iron deposits in the Bafq district and associated intrusions, and a younger age of 246 ± 17 Ma. The dark apatite yielded a U-Pb age of 437 ± 12 Ma. Our data suggest that hydrothermal magmatic fluids contributed to formation of the primary fluorapatite, and sodic and calcic alterations. The primary apatite reequilibrated with basinal brines in at least two regional extensions and basin developments in Silurian and Triassic in Central Iran.

Atomistic modelling study of lanthanide incorporation in the crystal lattice of an apatite; Etude par modelisation atomistique de l'incorporation de lanthanides dans le reseau cristallin d'une apatite phosphocalcique

Energy Technology Data Exchange (ETDEWEB)

Louis-Achille, V

1999-07-01

Studies of natural and synthetic apatites allow to propose such crystals as matrix for nuclear waste storage. The neodymium substituted britholite, Ca{sub 9}Nd(PO{sub 4}){sub 5}(SiO{sub 4})F{sub 2}. is a model for the trivalent actinide storage Neodymium can be substituted in two types of sites. The aim of this thesis is to compare the chemical nature of this two sites in fluoro-apatite Ca{sub 9}(PO{sub 4}){sub 6}F{sub 2} and then in britholite, using ab initio atomistic modeling. Two approaches are used: one considers the infinite crystals and the second considers clusters. The calculations of the electronic structure for both were performed using Kohn and Sham density functional theory in the local approximation. For solids, pseudopotentials were used, and wave functions are expanded in plane waves. For clusters, a frozen core approximation was used, and the wave functions are expanded in a linear combination of Slater type atomic orbitals. The pseudopotential is semi-relativistic for neodymium, and the Hamiltonian is scalar relativistic for the clusters. The validation of the solid approach is performed using two test cases: YPO{sub 4} and ScPO{sub 4}. Two numerical tools were developed to compute electronic deformation density map, and calculate partial density of stases. A full optimisation of the lattice parameters with a relaxation of the atomic coordinates leads to correct structural and thermodynamic properties for the fluoro-apatite, compared to experience. The electronic deformation density maps do not show any significant differences. between the two calcium sites. but Mulliken analysis on the solid and on the clusters point out the more ionic behavior of the calcium in site 2. A neodymium substituted britholite is then studied. Neodymium location only induces local modifications in; the crystalline structure and few changes in the formation enthalpy. The electronic study points out an increase of the covalent character the bonding involving neodymium

Formation of A-type granites in the Lower Yangtze River Belt: A perspective from apatite geochemistry

Science.gov (United States)

Jiang, Xiao-Yan; Li, He; Ding, Xing; Wu, Kai; Guo, Jia; Liu, Ji-Qiang; Sun, Wei-Dong

2018-04-01

Apatite is ubiquitous in A-type granites, and can be used to elucidate the volatile contents of the silicate melt, which reflect its source characteristics. A-type granites have been recognized as a distinct group of granites. A1- and A2-type subgroups are produced under different extensional settings. However, the details of the mechanisms behind the distinctive geochemical characteristics of A1- and A2-type granites remain obscure. Belts of Cretaceous A1- and A2-type granites occur along the Lower Yangtze River Belt in eastern China. Here we investigated the major and trace element compositions of apatites from contemporary A1- and A2-type granites at different localities along the Lower Yangtze River Belt, in order to decipher their discrepant source processes. Apatites from A1- and A2-type granites show similar major and trace elements, but differ in their F and Cl concentrations. Apatites from A1-type granites in the eastern part of the Lower Yangtze River Belt have much lower F and higher Cl concentrations compared to A2-type granites in the western part. Moreover, from the east to the west, the F concentrations of apatites from A1-type granites increase, while the Cl concentrations decline. In a subducted plate, F is retained by amphibole, chlorite, serpentine and mica minerals through the amphibolite stage, and finally by phengite and lawsonite during the eclogite stage, whereas, Cl is controlled by amphibole, chlorite and serpentine. The high and varied Cl concentrations in A1 subgroup apatites, therefore, may be attributed to the breakdown of amphibole, chlorite and/or serpentine decomposition during partial melting of subducted oceanic crust releasing a large amount of Cl at shallower depth. In contrast, F is transported to deeper depths in the subducted oceanic crust, and released through breakdown of phengite and lawsonite, making an important contribution to the formation of A2-type granites. Apatites from A1- and A2-type granite samples show regular

CARWASH WASTEWATERS: CHARACTERISTICS, VOLUMES, AND TREATABILITY BY GRAVITY OIL SEPARATION

OpenAIRE

C. Fall

2007-01-01

The aim of this research was to determine the characteristics, volumes and treatability of Full-service carwash wastewaters in Toluca (Mexico State). The average water use for Exterior-only wash was 50 L per small-size car and 170 L per medium-size vehicle (pick up, van or light truck). The Full-service wash (exterior, engine and chassis) required 170 L per small-size car and 300 L per light truck. Wastewaters were generally emulsified and contained high contaminant loads (in average, 1100 mg...

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

KAUST Repository

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

2013-01-01

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±0.2A/m2 (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. © 2013 Elsevier Ltd.

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

KAUST Repository

Ren, Lijiao

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±0.2A/m2 (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. © 2013 Elsevier Ltd.

Adsorption of Pb(II) present in aqueous solution on calcium, strontium and barium hydroxy apatites

International Nuclear Information System (INIS)

Vilchis G, J.

2013-01-01

Calcium, strontium and barium hydroxy apatites were successfully synthesized by chemical precipitation method, the obtained powders were characterized by the techniques of X-ray diffraction (XRD), scanning electron microscopy (Sem), semi-quantitative elemental analysis (EDS), infrared spectroscopy (IR), and N 2 physisorption studies, complementary to these analytical techniques, was determined the surface fractal dimension (Df), and the amount of surface active sites of the materials, in order to know application as ceramic for water remediation. The ability of Pb(II) ion adsorption present in aqueous solution on the hydroxy apatites synthesized by batch type experiments was studied as a function of contact time, concentration of the adsorbate and temperature. The maximum lead adsorption efficiencies obtained were 0.31, 0.32 and 0.26 mg/g for calcium, strontium and barium hydroxy apatites respectively, achieved an equilibrium time of 20 minutes in the three solid-liquid systems studied. Experimental data were adequately adjusted at the adsorption kinetic model pseudo-second order, for the three cases. Moreover, experimental data of the strontium and calcium hydroxy apatites were adjusted to the Langmuir adsorption isotherm, indicating that the adsorption was through a monolayer, whereas barium hydroxyapatite was adjusted to the Freundlich adsorption isotherm, indicating a multilayer adsorption. The thermodynamic parameters obtained during adsorption studies as a function of temperature showed physisorption, exothermic and spontaneous processes respectively. The results showed that the calcium hydroxyapatite, strontium and barium are an alternative for the Pb(II) ion adsorption present in wastewaters. (Author)

Morphological and chemical evaluation of bone with apatite-coated Al2O3 implants as scaffolds for bone repair

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A. L. M. Maia F.

2013-12-01

Full Text Available The clinical challenge in the reconstruction of bone defects has stimulated several studies in search of alternatives to repair these defects. The ceramics are considered as synthetic scaffolds and are used in dentistry and orthopedics. This study aimed to evaluate by micro energy-dispersive X-ray fluorescence spectrometry (µ-EDXRF and scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS, the influence of uncoated and apatite-coated Al2O3 implants on bone regeneration. Twelve samples of Al2O3 implants were prepared and half of this samples (n = 6 were apatite-coated by the modified biomimetic method and then the ceramic material were implanted in the tibia of rabbits. Three experimental groups were tested: Group C - control, surgery procedure without ceramic implant, Group Ce - uncoated Al2O3 implants (n = 6 and Group CeHA - apatite-coated Al2O3 implants (n = 6. The deposition of bone tissue was determined by measuring the weight content of Ca and P through surface mapping of bone-implant interface by µ-EDXRF and through point analysis by EDS. It was observed after thirty days of treatment a greater deposition of Ca and P in the group treated with CeHA (p <0.001 compared to group C. The results suggest that ceramic coated with hydroxyapatite (CeHA can be an auxiliary to bone deposition in tibia defect model in rabbits.

The increase of apatite layer formation by the poly(3-hydroxybutyrate) surface modification of hydroxyapatite and β-tricalcium phosphate.

Science.gov (United States)

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. © 2013.

U-Pb Data On Apatites With Common Lead Correction : Exemples From The Scottish Caledonides

Science.gov (United States)

Jewison, E.; Deloule, E.; Villeneuve, J.; Bellahsen, N.; Labrousse, L.; Rosenberg, C.; Pik, R.; Chew, D.

2017-12-01

Apatite is a widely used mineral in low-temperature thermochronology (U-Th/He and AFT). The use of apatite in U-Pb geochronology has a great potential, given its closure temperature around 450°C, for orogen thermostructural evolution studies. However, since apatite can accumulate significant amount of initial Pb in its structure, its use can be hindered by the lack of 204 Pb estimations. To work around this, two options are commonly used : either use a ploting sytem that does not require corrected ratios, or use a proxy to estimate 204Pb and use it to correct the ratios. In this study we use a SIMS to mesure 204Pb in order to compare Tera-Wasserburg diagram and corrected ages to examine the cooling pattern in the northern Highlands of Scotland. The Highlands is an extensively studied caledonian collision wedge which results from the closure of the Iapétus Ocean during the Orodivician-Silurian. Two orogenic events are related to this closing, the grampian event (480-460Ma) and the scandian event (435-415 Ma) that culminated in the stacking of major ductile thrusts. The thermal history of thoses nappes are hence complex and the cooling pattern poorly constrained. Corrected apatite U-Pb ages provide new constrains on ductile wedge building and improve our understanding of mid to lower-crustal deformation and orogenic exhumation. Thoses corrected ages yield equivalent errors and mean ages from the classic method. Those data suggest a global cooling younger than previously thought and a sequence departing from a simple forward sequence. We thus present a refined thermal evolution and conceptualize a model of ductile wedge evolution.

Project Work Plan: Sequestration of Strontium-90 Subsurface Contamination in the Hanford 100-N Area by Surface Infiltration of an Apatite Solution

Energy Technology Data Exchange (ETDEWEB)

Szecsody, Jim E.

2006-04-30

We propose to develop an infiltration strategy that defines the precipitation rate of an apatite-forming solution and Sr-90 sequestration processes under variably saturated (low water content) conditions. We will develop this understanding through small-scale column studies, intermediate-scale two-dimensional (2-D) experiments, and numerical modeling to quantify individual and coupled processes associated with apatite formation and Sr-90 transport during and after infiltration of the Ca-citrate-PO4 solution. Development of capabilities to simulate these coupled biogeochemical processes during both injection and infiltration will be used to determine the most cost-effective means to emplace an in situ apatite barrier with a longevity of 300 years to permanently sequester Sr-90 until it decays. Biogeochemical processes that will be investigated are citrate biodegradation and apatite precipitation rates at varying water contents as a function of water content. Coupled processes that will be investigated include the influence of apatite precipitation (which occupies pore space) on the hydraulic and transport properties of the porous media during infiltration.

In vivo bioactivity of titanium and fluorinated apatite coatings for orthopaedic implants: a vibrational study

Science.gov (United States)

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.

Age of hydrothermal processes in the central iberian zone (Spain according TO U-Pb dating of cassiterite and apatite

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Н. Г. Ризванова

2017-06-01

Full Text Available Results of isotope-geochemical studies by PbLS step-leaching method of cassiterite from greisens located in Logrosán granite massif (Central Iberian Zone, Spain and apatite from hydrothermal quartz-apatite vein on its exocontact indicate that in both cases a hydrothermal event is recorded in the interval of 114-126 Ma, which has been accompanied by lead supply. Within the limits of estimation error, the same age around 120 Ma corresponds to crystallization of hydrothermal apatite, formation of sticks and micro-inclusions in cassiterite from greisens and is suggested for Au-As-Sb-Pb ore mineralization, which calls for further confirmation. Xenogenous zircon from quartz-apatite vein does not react to this relatively low-temperature hydrothermal event either with building up new generations (sticks, areas of recrystallization or with rebalancing of U-Pb isotope system. The age of greisen formation has been confirmed to be around 305 Ma by PbLS method on final phases of cassiterite leaching. Earlier it was estimated with 40Ar/39Ar method on muscovite.

Apatite formation on organic polymers by biomimetic process using Na2O-SiO2 glasses as nucleating agent

Energy Technology Data Exchange (ETDEWEB)

Tanahashi, M; Yao, t; Kokubo, T [Kyoto University, Kyoto (Japan). Faculty of Engineering; Minoda, M; Miyamoto, T [Kyoto University, Kyoto (Japan). Institute for Chemical Research; Nakamura, T [Kyoto University, Kyoto (Japan). Research Center for Biomedical Engineering; Yamamuro, T [Kyoto University, Kyoto (Japan). Faculty of Medicine

1994-09-01

In this investigation, CaO-SiO2-based glass, which was previously used as the nucleating agent, was replaced by Na2O-SiO2 glasses, SiO2 glass, and SiO2 gel. The induction period for the apatite nucleation on various organic polymer substrates and the adhesive strength of the apatite layer to the substrates were examined. It was considered that the short induction period for the glasses with high Na2O contents was attributed to high dissolution rates of sodium and silicate ions from them. It was also considered that highly polar carboxyl or sulfinyl groups were formed on the polymer surfaces by the hydrolysis of their ester, amide or sulfonyl group in simulated body fluid with its pH increased by the Na{sup +} dissolution from the glass, and that these polar groups formed a strong bond with the apatite. It is suggested that thus formed apatite-organic polymer composites are useful as the bone-repairing as well as soft tissue-repairing materials. 11 refs., 13 figs., 3 tabs.

Quantum-mechanical calculations of the electronic structure of calcium and cadmium vanadate apatites

International Nuclear Information System (INIS)

Karbovskij, V.L.; Soroka, A.P.; Kasiyanenko, V.Kh.; Shpak, A.P.

2011-01-01

Electronic structures of compounds Me 10 (VO 4 ) 6 X 2 , where Me = Ca or Cd and X = F, Cl, OH are investigated using the full potential APW + lo method. The degrees of distortions of VO 4- tetrahedra with respect to the Td point group are analyzed using a relaxation of atomic positions. Apatites in the form of Ca 10 (VO 4 ) 6 X 2 , where X = F, Cl, OH, are established to decrease the band gap by 0.5-1.0 eV under the isomorphic substitution of calcium for cadmium. Apatites Ca 10 (VO 4 ) 6 X 2 , where X = F, Cl, OH are proven to decrease the degree of covalency of the oxygen-halogen bond under the isomorphic substitution of calcium for cadmium.

Biological Apatite Formed from Polyphosphate and Alkaline Phosphatase May Exchange Oxygen Isotopes from Water through Carbonate

Science.gov (United States)

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

Development and functioning of microorganisms in concentration cycles of sulfide copper-nickel and non-sulfide apatite-nepheline ores

Directory of Open Access Journals (Sweden)

Fokina N. V.

2017-03-01

Full Text Available The number and trophic diversity of bacteria in flotation samples of apatite-nepheline and sulfide copper-nickel ores at the concentration plants of JSC "Apatite" and Kola Mining and Metallurgical Company have been determined. The study of the size and diversity of the microbiota has been conducted by culture on selective nutrient media. The total number and biomass of bacteria have been considered by fluorescence microscopy using Cyclopore polycarbonate membrane filters. Bacteria have been identified by molecular genetic methods. The least amount of both saprotrophic and other trophic groups of bacteria has been observed in the samples of ore and recycled water as at the concentrating factory of Apatit JSC, and also at the plant "Pechenganikel". It has been found out that the bacteria contained in the ore and recycling water flowing from the tailings increased their number during the flotation process due to coming of the nutrients with the flotation reagents, aeration and increased temperature. Strains which occurrence is more than 60 % have been extracted from recycled water and basic flotation products and classified as Pseudomonas. Two strains with occurrence of more than 60 % have been discovered at Apatit JSC and classified as Stenotrophomonas and Acinetobacter. The number of fungi in the cycle of apatite-nepheline ore enrichment at the factories is very low (1 to 24 CFU / 1 ml or 1 g of ore. Fungi of the genus Penicillium have been dominated, fungi of the genera Acremonium, Aureobasidium, Alternaria, Chaetomium have also been detected. At the plant "Pechenganikel" species Aspergillus fumigatus, Penicillium aurantiogriseum and P. glabrum have been extracted. It has been shown that the bacteria deteriorate the apatite flotation as a result of their interaction with active centers of calcium-containing minerals and intensive flocculation decreasing the floatation selectivity. Also some trend of copper and nickel recovery change has been

Apatite ore mine tailings as an amendment for remediation of a lead-contaminated shooting range soil.

Science.gov (United States)

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, Øremediation technique at polluted sites. Copyright © 2011 Elsevier B.V. All rights reserved.

Crystal Structure Studies of Human Dental Apatite as a Function of Age

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Th. Leventouri

2009-01-01

Full Text Available Studies of the average crystal structure properties of human dental apatite as a function of age in the range of 5–87 years are reported. The crystallinity of the dental hydroxyapatite decreases with the age. The a-lattice constant that is associated with the carbonate content in carbonate apatite decreases with age in a systematic way, whereas the c-lattice constant does not change significantly. Thermogravimetric measurements demonstrate an increase of the carbonate content with the age. FTIR spectroscopy reveals both B and A-type carbonate substitutions with the B-type greater than the A-type substitution by a factor up to ~5. An increase of the carbonate content as a function of age can be deduced from the ratio of the 2CO3 to the 1PO4 IR modes.

Apatite formability of boron nitride nanotubes

International Nuclear Information System (INIS)

Lahiri, Debrupa; Keshri, Anup K; Agarwal, Arvind; Singh, Virendra; Seal, Sudipta

2011-01-01

This study investigates the ability of boron nitride nanotubes (BNNTs) to induce apatite formation in a simulated body fluid environment for a period of 7, 14 and 28 days. BNNTs, when soaked in the simulated body fluid, are found to induce hydroxyapatite (HA) precipitation on their surface. The precipitation process has an initial incubation period of ∼ 4.6 days. The amount of HA precipitate increases gradually with the soaking time. High resolution TEM results indicated a hexagonal crystal structure of HA needles. No specific crystallographic orientation relationship is observed between BNNT and HA, which is due to the presence of a thin amorphous HA layer on the BNNT surface that disturbs a definite orientation relationship.

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

Energy Technology Data Exchange (ETDEWEB)

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.

A note on frequency distributions of fission tracks in apatite

International Nuclear Information System (INIS)

He, Z.; Lerche, I.

1989-01-01

Two different formulae, both purportedly describing track length reduction in apatite, are converted to forms useful in prediction of track length distributions along sedimentary burial history paths. Using the formalism, track length distribution data from four NW Canning Basin wells are inverted to determine the physical (chemical) parameters associated with the models as well as the heat flux variation with time. For each formula the resulting physical parameters are consistent among the wells tested but differ from laboratory-derived parameter values, and the thermal histories are consistent with those inferred from geological data. Comparison of the two models shows no evidence that one model should be favored over the other based on the data available. It is also shown that the resolution of the parameters is dependent not only on the quantity of the data but also on the ''quality'' -explicitly upon the variation and distribution with depth. (author)

Treatability of volatile chlorinated hydrocarbon-contaminated soils of different textures along a vertical profile by mechanical soil aeration: A laboratory test.

Science.gov (United States)

Ma, Yan; Shi, Yi; Hou, Deyi; Zhang, Xi; Chen, Jiaqi; Wang, Zhifen; Xu, Zhu; Li, Fasheng; Du, Xiaoming

2017-04-01

Mechanical soil aeration is a simple, effective, and low-cost soil remediation technology that is suitable for sites contaminated with volatile chlorinated hydrocarbons (VCHs). Conventionally, this technique is used to treat the mixed soil of a site without considering the diversity and treatability of different soils within the site. A laboratory test was conducted to evaluate the effectiveness of mechanical soil aeration for remediating soils of different textures (silty, clayey, and sandy soils) along a vertical profile at an abandoned chloro-alkali chemical site in China. The collected soils were artificially contaminated with chloroform (TCM) and trichloroethylene (TCE). Mechanical soil aeration was effective for remediating VCHs (removal efficiency >98%). The volatilization process was described by an exponential kinetic function. In the early stage of treatment (0-7hr), rapid contaminant volatilization followed a pseudo-first order kinetic model. VCH concentrations decreased to low levels and showed a tailing phenomenon with very slow contaminant release after 8hr. Compared with silty and sandy soils, clayey soil has high organic-matter content, a large specific surface area, a high clay fraction, and a complex pore structure. These characteristics substantially influenced the removal process, making it less efficient, more time consuming, and consequently more expensive. Our findings provide a potential basis for optimizing soil remediation strategy in a cost-effective manner. Copyright © 2016. Published by Elsevier B.V.

Combination of Slag, Limestone and Sedimentary Apatite in Columns for Phosphorus Removal from Sludge Fish Farm Effluents

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Florent Chazarenc

2010-08-01

Full Text Available Laboratory scale studies have repeatedly reported high P-retention in slag, a by-product of the steel manufacturing industry. Thus, it has emerged as a potential material to increase P-removal from constructed wetlands (CWs. However, several limitations were highlighted by field experiments, including the high pH of treated water and clogging. We hypothesized that the addition of sedimentary rocks to slag would preserve P-removal properties while reducing the pH of treated water. Four 2.5 L-columns were filled with 100% apatite (column A; a 50% weight each mixture of limestone with apatite (column B; 10% steel slag located at the inlet, plus 45% limestone mixed with 45% apatite (column C; and a mixture of steel slag (10%, limestone (45% apatite (45% (column D. A synthetic effluent (26 mg P/L and a reconstituted sludge fish farm effluent containing 97 mg/L total suspended solids (TSS, 220 mg/L chemical oxygen demand (COD and 23.5 mg P/L phosphorus (P were applied sequentially during 373 and 176 days, under saturated flow conditions and 12–24 hours hydraulic residence time (HRT, respectively. Treatment performance, P-removal, pH and calcium (Ca2+ were monitored. Results indicated that columns that contained 10% weight steel slag resulted in a higher P retention capacity than the columns without steel slag. The highest P removal was achieved in column C, containing a layer of slag in the inlet zone, 45% apatite and 45% limestone. Feeding the columns with a reconstituted fish farm effluent led to biofilm development, but this had little effect on the P-removal. A combination of slag and sedimentary rocks represents a promising filtration material that could be useful downstream of CWs to further increase P-removal.

Nano-beta-tricalcium phosphates synthesis and biodegradation: 2. Biodegradation and apatite layer formation on nano-{beta}-TCP synthesized via microwave treatment

Energy Technology Data Exchange (ETDEWEB)

Abdel-Fattah, Wafa I; Elkhooly, Tarek A, E-mail: nrcfifi@yahoo.co [Department of Biomaterials, National Research Center, Cairo (Egypt)

2010-06-01

The degradation and/or apatite layer precipitation ability of porous {beta}-tricalcium phosphate ({beta}-TCP) samples treated and untreated with microwave radiation during synthesis is investigated. Microwave heating was used to accelerate the formation of CDHA with the Ca/P ratio 1.5 in a shorter processing time which later forms {beta}-TCP at around 650 {sup 0}C. Soaking in simulated body fluid (SBF) for several periods (4, 8, 12, 24, 36, 48, 60 and 72 h) is performed in a cumulative manner. The deposition of an apatite layer is followed through diffuse reflected FT-IR, SEM and EDS. A microwave-treated sample having a smaller particle size than its parent induces the formation of a homogeneous carbonated apatite layer on its surface. On the other hand, the parent {beta}-TCP sample exhibited less ability to induce Ca-P formation after being soaked in SBF. The formation of an apatite layer is attributed to the increase in surface area consequent to reduced particle and grain sizes besides the presence of a minor amount of hydroxyapatite phase in the microwave-treated {beta}-TCP sample. The results prove that it is possible to control the biodegradation and apatite layer formation on sintered {beta}-TCP porous disks through controlling the particle size.

Treatability study of pesticide-based industrial wastewater.

Science.gov (United States)

Shah, Kinnari; Chauhan, L I; Galgale, A D

2012-10-01

This paper finds out appropriate treatment methods for wastewater of an Organophosphorus viz, chloropyrifos pesticide manufacturing industry. The characterization of wastewater generated during trial production of chloropyrifos was carried out. Based on the characterization of wastewater, various treatability studies were conducted. The most desirable results were obtained with treatment scheme employing acidification, chlorination with NaOCl, suspended growth biological treatment, chemical precipitation for phosphorous removal and activated carbon treatment. Acidification of wastewater helps in by-product recovery as well as reduction in COD upto 36.26%. Chlorination followed by biological treatment was found to be effective to reduce the COD level by 62.06%. To comply with permissible limits prescribed by Effluent Channel Project Ltd.(ECPL)* and Gujarat Pollution Control Board (GPCB) for discharge of industrial effluent into channel, further treatment in the form of chemical precipitation (for phosphorous removal) and granular activated carbon is suggested.

Apatite intergrowths in clinopyroxene megacrysts from the Ostrzyca Proboszczowicka (SW Poland) basanite

Science.gov (United States)

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

The influence of channel anion identity on the high-pressure crystal structure, compressibility, and stability of apatite

Science.gov (United States)

Skelton, Richard; Walker, Andrew M.

2018-03-01

The material properties of the common phosphate mineral apatite are influenced by the identity of the channel anion, which is usually F-, Cl-, or (OH)-. Density functional theory calculations have been used to determine the effect of channel anion identity on the compressibility and structure of apatite. Hydroxyapatite and fluorapatite are found to have similar zero pressure bulk moduli, of 79.2 and 82.1 GPa, respectively, while chlorapatite is considerably more compressible, with K 0 = 55.0 GPa. While the space groups of hydroxyapatite and fluorapatite do not change between 0 and 25 GPa, symmetrization of the Cl- site in chlorapatite at 7.5 GPa causes the space group to change from P2 1 /b to P6 3 /m. Examination of the valence electron density distribution in chlorapatite reveals that this symmetry change is associated with a change in the coordination of the Cl- anion from threefold to sixfold coordinated by Ca. We also calculate the pressure at which apatite decomposes to form tuite, a calcium orthophosphate mineral, and find that the transition pressure is sensitive to the identity of the channel anion, being lowest for fluorapatite (13.8 GPa) and highest for chlorapatite (26.9 GPa). Calculations are also performed within the DFT-D2 framework to investigate the influence of dispersion forces on the compressibility of apatite minerals.

Increase of apatite dissolution rate by Scots pine roots associated or not with Burkholderia glathei PML1(12)Rp in open-system flow microcosms

Science.gov (United States)

Calvaruso, Christophe; Turpault, Marie-Pierre; Frey-Klett, Pascale; Uroz, Stéphane; Pierret, Marie-Claire; Tosheva, Zornitza; Kies, Antoine

2013-04-01

The release of nutritive elements through apatite dissolution represents the main source of phosphorus, calcium, and several micronutrients (e.g., Zn, Cu) for organisms in non-fertilized forest ecosystems. The aim of this study was to quantify, for the first time, the dissolution rate of apatite grains by tree roots that were or were not associated with a mineral weathering bacterial strain, and by various acids known to be produced by tree roots and soil bacterial strains in open-system flow microcosms. In addition, we explored whether the mobilization of trace elements (including rare earth elements) upon apatite dissolution was affected by the presence of trees and associated microorganisms. The dissolution rate of apatite by Scots pine plants that were or were not inoculated with the strain Burkholderia glathei PML1(12)Rp, and by inorganic (nitric) and organic (citric, oxalic and gluconic) acids at pH 5.5, 4.8, 3.8, 3.5, 3.0, and 2.0 was monitored in two controlled experiments: "plant-bacteria interaction" and "inorganic and organic acids". Analyses of the outlet solutions in the "plant-bacteria interaction" experiment showed that Scots pine roots and B. glathei PML1(12)Rp produced protons and organic acids such as gluconate, oxalate, acetate, and lactate. The weathering budget calculation revealed that Scots pines (with or without PML1(12)Rp) significantly increased (factor > 10) the release of Ca, P, As, Sr, Zn, U, Y, and rare earth elements such as Ce, La, Nd from apatite, compared to control abiotic treatment. Scanning electron microscopy observation confirmed traces of apatite dissolution in contact of roots. Most dissolved elements were taken up by Scots pine roots, i.e., approximately 50% of Ca, 70% of P, 30% of As, 70% of Sr, 90% of Zn, and 100% of U, Y, and rare earth elements. Interestingly, no significant additional effect due to the bacterial strain PML1(12)Rp on apatite dissolution and Scots pine nutrition and growth was observed. The "inorganic

Study of the dissolution of three synthetic minerals: zirconolite, Y-britholite and mono-silicate fluor-apatite; Etude de la solubilite de trois mineraux synthetiques: la zirconolite, la britholite-Y et la fluorapatite monosilicatee

Energy Technology Data Exchange (ETDEWEB)

Kamel, N.E.H.; Telmoune, S.A. [Centre de Recherche Nucleaire d' Alger, Div. des Techniques Nucleaires, Alger (Algeria); Ait-Amar, H. [Unitersite des Sciences et de la Technologie Houari Boumediene, Dept. de Genie des Procedes, Alger (Algeria)

2007-11-15

In this study, we were interested in the synthesis by natural sintering of three minerals analogue of natural rocks: zirconolite, Y-britholite and mono-silicated fluor-apatite. Cerium was used as an actinide surrogate. A simple physical characterization of the materials was made by X-ray diffraction and by measuring both densities and hardnesses. A static leaching test allowed determining the cerium immobilization capacity of the minerals. The most stable mineral was mono-silicated fluor-apatite, with a maximum amount of released cerium less than 2 %. For zirconolite and Y-britholite, this amount reached 15 and 18 % of the total cerium in the minerals, respectively. For the latter compounds, the cerium content in the materials was too weak, and the chosen synthesis method gave less satisfactory physicochemical mineral properties compared to those obtained for mono-silicated fluor-apatite. (authors)

Carbonate loss from two magnesium-substituted carbonated apatites prepared by different synthesis techniques

International Nuclear Information System (INIS)

Barinov, S.M.; Rau, J.V.; Fadeeva, I.V.; Cesaro, S. Nunziante; Ferro, D.; Trionfetti, G.; Komlev, V.S.; Bibikov, V.Yu.

2006-01-01

This study was aimed at the investigation of the thermal stability of Mg-substituted carbonated apatites over the wide temperature range. Two different apatites were studied, which were prepared by either precipitation from aqueous solution or by solid-liquid interaction. The following methods were employed: FTIR spectroscopy of the condensed gas phase to evaluate the CO and CO 2 release with increasing temperature, FTIR of the solid residue after heating, XRD analysis, thermogravimetry and scanning electron microscopy. Decomposition behavior was shown to depend significantly on the synthesis method. Wet-synthesized powders are significantly less thermally stable compared with those prepared by solid-liquid interaction. Intensive release of carbon oxides from the former was observed at 300 deg. C, whereas the latter powder was relatively stable up to temperature about 1000 deg. C

Development of guidance for preparing treatability variance petitions from the RCRA Land Disposal Restrictions for DOE [Department of Energy] mixed-waste streams

International Nuclear Information System (INIS)

Harms, T.; Scheuer, N.; Martin, R.; Van Epp, T.; Triplett, M.

1990-01-01

In response to the Department of Energy's (DOE) anticipated need for variances from the Resource Conservation and Recovery Act (RCRA) Land Disposal Restriction (LDR) treatment requirements, a treatability variance guidance document is being prepared for use by DOE facilities and operations offices. The guidance document, although applicable to non-mixed hazardous waste streams, provides specific guidance regarding radioactive mixed-waste streams. Preparation of the guidance manual has involved developing an overview of the Land Disposal Restrictions, as well as an overview of the petition preparation process. The DOE internal review requirements are specifically addressed in the manual. Specific data requirements and engineering analyses are also described. A discussion of EPA's criteria for granting a treatability variance is also provided. A checklist for completeness of the petition is provided. Model language for use in DOE treatability variance petitions will be provided in a petition for a DOE waste stream as an appendix to the document

Formation of apatite on hydrogenated amorphous silicon (a-Si:H) film deposited by plasma-enhanced chemical vapor deposition

International Nuclear Information System (INIS)

Liu Xuanyong; Chu, Paul K.; Ding Chuanxian

2007-01-01

Hydrogenated amorphous silicon films were fabricated on p-type, 100 mm diameter silicon wafers by plasma-enhanced chemical vapor deposition (PECVD) using silane and hydrogen. The structure and composition of the hydrogenated amorphous silicon films were investigated using micro-Raman spectroscopy and cross-sectional transmission electron microscopy (XTEM). The hydrogenated amorphous silicon films were subsequently soaked in simulated body fluids to evaluate apatite formation. Carbonate-containing hydroxyapatite (bone-like apatite) was formed on the surface suggesting good bone conductivity. The amorphous structure and presence of surface Si-H bonds are believed to induce apatite formation on the surface of the hydrogenated amorphous silicon film. A good understanding of the surface bioactivity of silicon-based materials and means to produce a bioactive surface is important to the development of silicon-based biosensors and micro-devices that are implanted inside humans

Formation of apatite on hydrogenated amorphous silicon (a-Si:H) film deposited by plasma-enhanced chemical vapor deposition

Energy Technology Data Exchange (ETDEWEB)

Liu Xuanyong [Shanghai Institute of Ceramics, Chinese Academy of Sciences, 1295 Dingxi Road, Shanghai 200050 (China) and Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong (China)]. E-mail: xyliu@mail.sic.ac.cn; Chu, Paul K. [Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong (China)]. E-mail: paul.chu@cityu.edu.hk; Ding Chuanxian [Shanghai Institute of Ceramics, Chinese Academy of Sciences, 1295 Dingxi Road, Shanghai 200050 (China)

2007-01-15

Hydrogenated amorphous silicon films were fabricated on p-type, 100 mm diameter <1 0 0> silicon wafers by plasma-enhanced chemical vapor deposition (PECVD) using silane and hydrogen. The structure and composition of the hydrogenated amorphous silicon films were investigated using micro-Raman spectroscopy and cross-sectional transmission electron microscopy (XTEM). The hydrogenated amorphous silicon films were subsequently soaked in simulated body fluids to evaluate apatite formation. Carbonate-containing hydroxyapatite (bone-like apatite) was formed on the surface suggesting good bone conductivity. The amorphous structure and presence of surface Si-H bonds are believed to induce apatite formation on the surface of the hydrogenated amorphous silicon film. A good understanding of the surface bioactivity of silicon-based materials and means to produce a bioactive surface is important to the development of silicon-based biosensors and micro-devices that are implanted inside humans.

Treatability of PCB-contaminated soils with quicklime (CaO)

International Nuclear Information System (INIS)

Mauro, D.; Taylor, B.B.

1992-12-01

The possibility that quicklime (calcium oxide, CaO) can destroy PCBs has received much attention over the past year. Observations at an EPA remediation site, where lime-containing kiln dusts were used for interim stabilization of PCB-containing wastes prompted the EPA to sponsor a small research project to investigate quicklime-PCB interactions. That study reported decreases in PCB content in synthetic, PCB-spiked soil following the application of quicklime and heat. META Environmental, Inc., as a contractor to EPRI, recently completed research designed to evaluate the effectiveness of quicklime for treating PCBs in soil and sand matrices under several reaction conditions, and to examine the underlying dechlorination chemistry involved, if any. Experiments were run with PCB-spiked sand and with actual PCB-contaminated soil. A variety of experimental conditions were employed including tests in open and closed containers, at ambient and elevated temperatures, and over a range of one hour to four days. Granular quicklime, fly ash, and kiln dust were all tested for reaction with PCBs. Early experiments showed that a mixture of sand/quicklime/water at 1:3:1.5 by weight, placed in an insulated container reached a maximum temperature of 216 degree C. Treatability experiments were subsequently run under controlled heat at room temperature, at 80 degree C, and at 200 degree C (following the initial temperature increase which occurs when water is added to quicklime). Little or no loss of PCBs was observed in open or closed containers at ambient or at 800 degree C over any period of time studied. A significant decrease of PCBs levels was observed only in the high temperature experiments (above 200 degree C), however the fate of the PCBs in those experiments was not determined. The conditions and the results of the PCB treatment tests are presented in this report, as well as recommendations for further studies

The effect of secondary apatite on the initial 87Sr/86Sr ratio determination in granitic rocks: a case study of the Tadamigawa pluton, northeastern Japan

Science.gov (United States)

Wakasugi, Y.; Ichino, K.; Tanioka, Y.; Wakaki, S.; Tsuboi, M.; Ishikawa, T.

2017-12-01

Apatite is a major accessory mineral in igneous rocks. Because Rb contents in apatite are very low, 87Sr/86Sr ratios of magmatic apatite are useful to estimate the initial 87Sr/86Sr ratio (SrI) of igneous rocks. Secondary post-magmatic event such as hydrothermal alteration may also crystallize secondary apatite, which may inhibit the estimation of SrI of igneous rocks. In this study, we examine the effects of secondary apatite on the initial 87Sr/86Sr ratio determination of granitic rocks by using acid leaching technique. Leached apatite samples were first separated from the whole rock powder as a heavy mineral fraction by heavy liquid technique, and the heavy mineral fraction was then leached by 3 M HNO3. The isotopic ratios of Sr and the concentrations of Rb and Sr were analyzed by TIMS and ICP-MS at Kochi Core Center, respectively. The Tadamigawa Older-stage granites, which locate in the Taishaku Mountains at the northeastern part of Japan, intrude into the Ashio Jurassic complex, and the ages of these rocks are late Cretaceous to Paleogene. The U-Pb ages of zircon and the K-Ar ages of biotite for these rocks are c. 100 Ma [1, 2]. Rb-Sr whole-rock isochron age of the pluton is 96.5 ± 1.3 Ma (SrI = 0.70534 ± 0.00003) and it is concordant with other radiometric ages. Rb-Sr mineral isochron ages range from 84.4 to 97.3 Ma and these ages are relatively younger than the Rb-Sr whole-rock isochron age. The difference among radiometric ages may reflect the difference of the closure temperature in each isotopic system. The Tadamigawa Older-stage granites have SrI for Rb-Sr mineral isochron range from 0.7053 to 0.7061 and are very similar to that (0.70534) for Rb-Sr whole-rock isochron. These may suggest that the Tadamigawa Older-stage granites are generated from same parental magma. However, 87Sr/86Sr ratios of the leached apatite samples were 0.70544-0.70856 and are relatively higher than SrI obtained from the Rb-Sr mineral isochrons (0.7053-0.7061). This result

A new hydrometallurgical process for extracting rare earths from apatite using solvent extraction with P35

International Nuclear Information System (INIS)

Li Hongfei; Guo Fuqiang; Zhang Zhifeng; Li Deqian; Wang Zhonghuai

2006-01-01

In this paper, a new process is proposed to recover rare earths from nitric acid leaching of apatite without interfering with the normal route for fertilizer production using solvent extraction with dimethyl heptyl methyl phosphonate CH 3 P(O)(OC 8 H 17 ) 2 (P 35 , B). In the present work, the leaching conditions are studied. In selected condition, apatite was dissolved in 20% (v/v) nitric acid solution at 60-70 deg. C while agitating. The most suitable acidity for extraction is 0.4 M HNO 3 . More than 98% of rare earths in apatite can be recovered using countercurrent extraction process with six stages when phase ratio = 0.5, and defluorination is unnecessary. The influences of phase ratio, stage number, acidity and salting-out agent on extractabilities of P 35 are studied. The results show that rare earths can be separated with P 35 from Ca, P, Fe and other impurities. Mixed rare earth oxides (REO) of which purity is more than 95% with yield over 98% can be obtained

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

Directory of Open Access Journals (Sweden)

Okonkwo Kevin O

2009-02-01

Full Text Available Abstract 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

In-Situ Grouting Treatability Study for the Idaho National Engineering and Environmental Laboratory Subsurface Disposal Area-Transuranic Pits and Trenches

International Nuclear Information System (INIS)

Loomis, G. G.; Jessmore, J. J.; Sehn, A. L.; Miller, C. M.

2002-01-01

At the Idaho National Engineering and Environmental Laboratory (INEEL), a Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) treatability study is being performed to examine the technology of in situ grouting for final in situ disposal of buried mixed transuranic (TRU) waste. At the INEEL, there is over 56,000 cubic meters of waste commingled with a similar amount of soil in a shallow (3-5 m) land burial referred to as Waste Area Group 7-13/14. Since this buried waste has been declared on the National Priorities List under CERCLA, it is being managed as a superfund site. Under CERCLA, options for this waste include capping and continued monitoring, retrieval and ex situ management of the retrieved waste, in situ stabilization by vitrification or grouting, in situ thermal dissorption, or some combination of these options. In situ grouting involves injecting grout at high pressures (400 bars) directly into the waste to create a solid monolith. The in situ grouting process is expected to both stabilize the waste against subsidence and provide containment against migration of waste to the Snake River Plain Aquifer lying 150-200 m below the waste. The treatability study involves bench testing, implementability testing, and field testing. The bench testing was designed to pick three grouts from six candidate grouts for the implementability field testing in full scale which were designed to down-select from those three grouts to one grout for use in a full-scale field demonstration of the technology in a simulated test pit. During the bench testing, grouts were evaluated for durability using American Nuclear Society 16.1 Leach Protocol as well as evaluating the effect on physical parameters such as hydraulic conductivity and compressive strength due to the presence of interferences such as soil, organic sludge, and nitrate salts. During full-scale implementability testing, three grouts were evaluated for groutability and monolith formation

Apatite fission track dating and thermal history of Qing-He region in Altay Mountains

International Nuclear Information System (INIS)

Bao Zengkuan; Chinese Academy of Sciences, Beijing; Yuan Wanming; Dong Jinquan; Gao Shaokai

2005-01-01

Fission track ages (FTA) and track lengths of apatite from Qing-He diorite intrusion in Altay Mountains are measured. Apatite fission track ages of three diorite samples is range from (78±5) Ma to (95 ± 5) Ma, and the lengths of horizontal confined spontaneous fission tracks are (13.2 ± 1.2)-(13.5 ±1.3) μm. The distribution of the track length is narrow and symmetrical with a mean length of approximately 13.3 μm and a standard deviation of around 0.1 μm. The inverse modeling results show that thermal history of this region has four stages, two rapid uplift of this region still existed magmatic intrusion and tectonic movements in Yanshanian. (authors)

Development of layered anode structures supported over Apatite-type Solid Electrolytes

Directory of Open Access Journals (Sweden)

Pandis P.

2016-01-01

Full Text Available Apatite-type lanthanum silicates (ATLS materials have attracted interest in recent literature as solid electrolytes for SOFCs. The fabrication of an ATLS based fuel cell with the state-of-art electrodes (NiO/YSZ as anode and LSCF or LSM as cathode can show degradation after long operation hours due to Si diffusion mainly towards the anode. In this work, we report a “layer-by-layer anodic electrodes” fabrication by means of spin coating and physical spraying. The overall aim of this work is the successful fabrication of such a layered structure including suitable blocking layers towards the inhibition of Si interdiffusion from the apatite electrolyte to the anode. The results showed that the deposition of 3 layers of LFSO/GDC (3μm, NiO/GDC (4μm and the final NiO/YSZ anode layer provided a stable half-cell, with no solid state reaction occurring among the electrodes and no Si diffusion observed towards the anode after thermal treatment at 800°C for 120h.

Thermal and exhumation history of Sakhalin Island (Russia) constrained by apatite U-Pb and fission track thermochronology

Science.gov (United States)

Glorie, Stijn; Alexandrov, Igor; Nixon, Angus; Jepson, Gilby; Gillespie, Jack; Jahn, Bor-Ming

2017-08-01

Sakhalin Island represents a key locality to study the tectonic evolution of the western Pacific. The island is located at the Amur-Okhotsk plate margin and records a complex thermotectonic history. Apatite double dating (U-Pb and fission track) and thermal history modelling were applied to three late Eocene granitoid massifs within central and southern Sakhalin: the Aniva, Okhotsk and Langeri complexes. Apatite U-Pb results yield consistent late Eocene (∼40-37 Ma) ages, suggesting rapid post-magmatic cooling. Apatite fission track results reveal bimodal age distributions with late Eocene - early Oligocene (∼38-33 Ma) and early Miocene (∼20-17 Ma) age populations that can be correlated with variations in Uranium and Chlorine concentrations. Thermal history modelling translates the AFT age bimodality into two-phase cooling histories. The timing of the early cooling phase (∼38-33 Ma) corresponds with the apatite U-Pb ages, indicating rapid cooling to at least ∼100 °C during the late Oligocene. The second cooling phase at ∼20-17 Ma cooled the samples to near-surface temperatures. Both cooling phases correspond with regional unconformities and subsequent accelerations in sedimentation rate, suggesting that cooling was a response to rapid exhumation. In addition, our data suggests that the studied terranes record differential exhumation with respect to the structural architecture. The Miocene exhumation pulse is coeval with the timing of transpressional fault displacement and the subsequent opening of the Kuril Basin.

300 Area Uranium Stabilization Through Polyphosphate Injection: Final Report

Energy Technology Data Exchange (ETDEWEB)

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

2009-06-30

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. This report summarizes the work on the polyphosphate injection project, including bench-scale laboratory studies, a field injection test, and the subsequent analysis and interpretation of the results. Previous laboratory tests have demonstrated that when a soluble form of polyphosphate is injected into uranium-bearing saturated porous media, immobilization of uranium occurs due to formation of an insoluble uranyl phosphate, autunite [Ca(UO2)2(PO4)2•nH2O]. These tests were conducted at conditions expected for the aquifer and used Hanford soils and groundwater containing very low concentrations of uranium (10-6 M). Because autunite sequesters uranium in the oxidized form U(VI) rather than forcing reduction to U(IV), the possibility of re-oxidation and subsequent re-mobilization is negated. Extensive testing demonstrated the very low solubility and slow dissolution kinetics of autunite. In addition to autunite, excess phosphorous may result in apatite mineral formation, which provides a long-term source of treatment capacity. Phosphate arrival response data indicate that, under site conditions, the polyphosphate amendment could be effectively distributed over a relatively large lateral extent, with wells located at a radial distance of 23 m (75 ft) reaching from between 40% and 60% of the injection concentration. Given these phosphate transport characteristics, direct treatment of uranium through the formation of uranyl-phosphate mineral phases (i.e., autunite) could likely be effectively implemented at full field scale. However, formation of calcium-phosphate mineral phases using the selected three-phase approach was problematic. Although

Oxygen isotope variations in phosphate of biogenic apatites. Pt. 2. Phosphorite rocks

Energy Technology Data Exchange (ETDEWEB)

Kolodny, Y; Luz, B; Shemesh, A [Hebrew Univ., Jerusalem (Israel). Dept. of Geology

1983-09-01

Phosphorites from sedimentary sequences ranging in age from Archaen to Recent were analysed for delta/sup 18/O in both the PO/sub 4/ (delta/sup 18/Osub(p)) and CO/sub 3/ (delta/sup 18/Osub(c)) in the apatite lattice. The oxygen isotope record is considerably better preserved in phosphates than in either carbonates or cherts. The use of the Longinelli and Nuti temperature equation yields temperatures for Recent phosphorites that are in good agreement with those measured in the field. The delta/sup 18/Osub(p) values of ancient phosphorites decrease with increasing age. These changes with time are not likely to be due to post-depositional exchange. Changes in delta/sup 18/O values of seawater and variations of temperatures with time can account for the delta/sup 18/Osub(p) time trend, but the latter explanation is preferred. In Ancient phosphorites delta/sup 18/Osub(c) in structurally bound carbonate in apatite is not a reliable geochemical indicator.

Development of a treatability variance guidance document for US DOE mixed-waste streams

International Nuclear Information System (INIS)

Scheuer, N.; Spikula, R.; Harms, T.

1990-03-01

In response to the US Department of Energy's (DOE's) anticipated need for variances from the Resource Conservation and Recovery Act (RCRA) Land Disposal Restrictions (LDRs), a treatability variance guidance document was prepared. The guidance manual is for use by DOE facilities and operations offices. The manual was prepared as a part of an ongoing effort by DOE-EH to provide guidance for the operations offices and facilities to comply with the RCRA (LDRs). A treatability variance is an alternative treatment standard granted by EPA for a restricted waste. Such a variance is not an exemption from the requirements of the LDRs, but rather is an alternative treatment standard that must be met before land disposal. The manual, Guidance For Obtaining Variance From the Treatment Standards of the RCRA Land Disposal Restrictions (1), leads the reader through the process of evaluating whether a variance from the treatment standard is a viable approach and through the data-gathering and data-evaluation processes required to develop a petition requesting a variance. The DOE review and coordination process is also described and model language for use in petitions for DOE radioactive mixed waste (RMW) is provided. The guidance manual focuses on RMW streams, however the manual also is applicable to nonmixed, hazardous waste streams. 4 refs

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

Science.gov (United States)

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...

In situ vitrification laboratory-scale test work plan

International Nuclear Information System (INIS)

Nagata, P.K.; Smith, N.L.

1991-05-01

The Buried Waste Program was established in October 1987 to accelerate the studies needed to develop a long-term management plan for the buried mixed waste at the Radioactive Waste Management Complex at Idaho 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 mixed buried waste. To support the overall feasibility study, the situ vitrification treatability investigations are proceeding along the three parallel paths: laboratory-scale tests, intermediate field tests, and field tests. Laboratory-scale tests are being performed to provide data to mathematical modeling efforts, which, in turn, will support design of the field tests and to the health and safety risk assessment. This laboratory-scale test work plan provides overall testing program direction to meet the current goals and objectives of the in situ vitrification treatability investigation. 12 refs., 1 fig., 7 tabs

Contribution to the study of sorption mechanisms at solid-liquid interfaces: application to the cases of apatites and oxy-hydroxides; Contribution a l'etude des mecanismes de sorption aux interfaces solide-liquide: application aux cas des apatites et des oxy-hydroxydes

Energy Technology Data Exchange (ETDEWEB)

Duc, M

2002-11-15

Sorption-desorption phenomena play an important role in the transport of toxic and radioactive elements in surface and underground water in contact with solid matter. Selenium, which is one of the long-lived radionuclides present in radioactive waste, is characterized by several oxidation states and by anionic species in aqueous solutions. In order to predict its transport, we need a good knowledge of its sorption processes. We have studied the sorption of Se(IV) and Se(VI) on two types of solids present in natural media or which have been proposed as additives to active barriers: hydroxy-apatites, fluoro-apatite and iron oxi-hydroxides (goethite and hematite). Sorption mechanisms have been studied through an approach including several different and complementary methods: titrimetry, zeta-metry, scanning and transmission electron microscopy, infrared spectroscopy, X-ray diffraction, X-ray photo electron spectroscopy, etc... Results showed that Se(VI) is much less sorbed than Se(VI) on both types of solids. For Se(IV) the sorption mechanisms are different for iron oxides and apatites. On oxides, sorption increases when pH decreases. It can be interpreted by a surface complexation model, essentially through an inner sphere complex (monodentate or bidentate). Modelling of Se sorption curves was performed after the determination of acido-basic properties of oxides. However, the determination of the intrinsic properties of oxides is disturbed by several parameters identified as impurities, evolution of the solid in solution, kinetic and solubility of the solid. For apatites, selenium sorption proceeds by exchange with superficial groups, with a maximum of fixation at approximately pH 8. Thanks to XPS measurements and the elaboration of a mathematical model, we could determine the depth of penetration of both selenium and cadmium on apatites. (author)

Genesis of iron-apatite ores in Posht-e-Badam Block (Central Iran ...

Indian Academy of Sciences (India)

Central Iran; iron-apatite ore; Kiruna-type; Posht-e-Badam Block; REE geochemistry. J. Earth Syst ... ferent ore genesis models have been proposed for ...... volatile-rich magma systems stress the important .... Laco magnetite flow deposits, northern Chile: An up-to- ... economic report on iron ore prevision of the Esfahan steel.

Treatability studies of alternative wastewaters for Metal Finishing Effluent Treatment Facility

International Nuclear Information System (INIS)

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

1994-01-01

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

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

International Nuclear Information System (INIS)

1998-01-01

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 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 limits

High temperature (>350 °C) thermal histories of the long lived (>500 Ma) active margin of Ecuador and Colombia: Apatite, titanite and rutile U-Pb thermochronology

Science.gov (United States)

Paul, Andre N.; Spikings, Richard A.; Ulianov, Alexey; Ovtcharova, Maria

2018-05-01

Quantitative reconstruction of thermal histories can be a powerful tool to study numerous natural processes such as tectonic plate interaction, cratonic stability and extra-terrestrial phenomena such as asteroid ejection. A majority of thermochronological studies have focused on temperatures lower than 300 °C. Few previous studies have demonstrated that U-Pb data from apatite and other accessory phases can be used to recover thermal history information at T > 350 °C. We present U-Pb data from apatite, to constrain the thermal histories of Triassic peralluminous anatectites from the Northern Andes between the temperatures of ∼350-550 °C. The accuracy of the thermal history models is assessed by comparisons with previous geological models, and comparisons with pre-existing and newly acquired U/Pb (titanite and rutile), 40Ar/39Ar (muscovite) and low temperature thermochronological data. This study also examines the feasibility of using a large, regionally dispersed apatite U-Pb data set to obtain continuous thermal history paths along a long-lived (>500 Ma) active margin. A second aim of this study is to further test the hypothesis that the dominant mechanism for Pb displacement through apatite is volume diffusion, as opposed to aqueous fluid interaction. The thermal history models derived from the Triassic anatectites exposed in the Andes of Colombia and Ecuador are entirely consistent with lower temperature thermochronological constraints, and previously established geochronological and geochemical constraints. They reveal and quantify trench parallel changes in the amount of Jurassic - Early Cretaceous extension, significantly bolstering and adding to previous tectonic interpretations. Confirmation of the utility of U-Pb thermochronology provides geologists with a powerful tool for investigating the high-temperature thermal evolution of accessory minerals.

Highly porous polymer-derived wollastonite-hydroxycarbonate apatite ceramics for bone regeneration.

Science.gov (United States)

Fiocco, L; Li, S; Bernardo, E; Stevens, M M; Jones, J R

2016-04-12

A novel strategy was employed to synthesize highly porous wollastonite-hydroxycarbonate apatite ceramic scaffolds for bone regeneration. A commercial liquid preceramic polymer filled with micro-CaCO3 powders was foamed at low temperature (at 350 °C), using the decomposition of a hydrazine additive, and then converted into ceramic by a treatment at 700 °C. Hydroxycarbonate apatite was later developed by a phosphatization treatment of ceramized foams, in a P-rich solution, while wollastonite was obtained by a second firing, at 900 °C. The effectiveness of the method was proven by x-ray diffraction analysis, showing the presence of the two expected crystalline phases. Porosity, interconnect size distribution and mechanical strength were in the range that is thought to be suitable for bone regeneration in non-load bearing sites (compressive strength ≈ 3 MPa, porosity ≈ 90%, modal interconnect diameter ≈ 130-160 μm). In addition, bioactivity and ion release rate were assessed in simulated body fluid (SBF). MC3T3 osteoblast precursor cells were able to colonize the material in vitro through the pore architecture and expressed osteogenic markers.

Devonian climate and reef evolution: Insights from oxygen isotopes in apatite

Science.gov (United States)

Joachimski, M. M.; Breisig, S.; Buggisch, W.; Talent, J. A.; Mawson, R.; Gereke, M.; Morrow, J. R.; Day, J.; Weddige, K.

2009-07-01

Conodonts, microfossils composed of carbonate-fluor apatite, are abundant in Palaeozoic-Triassic sediments and have a high potential to preserve primary oxygen isotope signals. In order to reconstruct the palaeotemperature history of the Devonian, the oxygen isotope composition of apatite phosphate was measured on 639 conodont samples from sequences in Europe, North America and Australia. The Early Devonian (Lochkovian; 416-411 Myr) was characterized by warm tropical temperatures of around 30 °C. A cooling trend started in the Pragian (410 Myr) with intermediate temperatures around 23 to 25 °C reconstructed for the Middle Devonian (397-385 Myr). During the Frasnian (383-375 Myr), temperatures increased again with temperatures to 30 °C calculated for the Frasnian-Famennian transition (375 Myr). During the Famennian (375-359 Myr), surface water temperatures slightly decreased. Reconstructed Devonian palaeotemperatures do not support earlier views suggesting the Middle Devonian was a supergreenhouse interval, an interpretation based partly on the development of extensive tropical coral-stromatoporoid communities during the Middle Devonian. Instead, the Devonian palaeotemperature record suggests that Middle Devonian coral-stromatoporoid reefs flourished during cooler time intervals whereas microbial reefs dominated during the warm to very warm Early and Late Devonian.

Sorption behavior of Zn(II) ions on synthetic apatitic calcium phosphates

Science.gov (United States)

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.

Treatability of a Highly-Impaired, Saline Surface Water for Potential Urban Water Use

Directory of Open Access Journals (Sweden)

Frederick Pontius

2018-03-01

Full Text Available As freshwater sources of drinking water become limited, cities and urban areas must consider higher-salinity waters as potential sources of drinking water. The Salton Sea in the Imperial Valley of California has a very high salinity (43 ppt, total dissolved solids (70,000 mg/L, and color (1440 CU. Future wetlands and habitat restoration will have significant ecological benefits, but salinity levels will remain elevated. High salinity eutrophic waters, such as the Salton Sea, are difficult to treat, yet more desirable sources of drinking water are limited. The treatability of Salton Sea water for potential urban water use was evaluated here. Coagulation-sedimentation using aluminum chlorohydrate, ferric chloride, and alum proved to be relatively ineffective for lowering turbidity, with no clear optimum dose for any of the coagulants tested. Alum was most effective for color removal (28 percent at a dose of 40 mg/L. Turbidity was removed effectively with 0.45 μm and 0.1 μm microfiltration. Bench tests of Salton Sea water using sea water reverse osmosis (SWRO achieved initial contaminant rejections of 99 percent salinity, 97.7 percent conductivity, 98.6 percent total dissolved solids, 98.7 percent chloride, 65 percent sulfate, and 99.3 percent turbidity.

Geodynamic risk magnitude as an objective indicator of rockburst prevention effectiveness (in terms of apatite mines in Khibiny)

Science.gov (United States)

Fedotova Panin, YuV, VI

2018-03-01

The results of the statistical retrospective analysis of the officially recorded geodynamic events in mines of Apatit Company within the Khibiny Massif are presented. The risks and aftereffects of geodynamic events have been calculated. Under discussion are the results of three calculation variants taking into account the scale of human impact on rock mass. The analysis shows that the main damage due to geodynamic events is different-degree destruction of mine workings while the remaining aftereffects account for less than ten percent. That is, the geodynamic risk in apatite mines can be identified as technological.

Normal-pressure hydrocephalus and the saga of the treatable dementias

International Nuclear Information System (INIS)

Friedland, R.P.

1989-01-01

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

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

Science.gov (United States)

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. Copyright © 2015 Elsevier B.V. All rights reserved.

Denudation history of the Snowy Mountains: constraints from apatite fission track thermochronology

International Nuclear Information System (INIS)

Kohn, B.P.; Gleadow, A.J.W.; Cox, S.J.D.

1999-01-01

Apatite fission track thermo chronology from Early Palaeozoic granitoids centred around the Kosciuszko massif of the Snowy Mountains, records a denudation history that was episodic and highly variable. The form of the apatite fission track age profile assembled from vertical sections and hydro-electric tunnels traversing the mountains, together with numerical forward modelling, provide strong evidence for two episodes of accelerated denudation, commencing in Late Permian - Early Triassic (ca 270 250 Ma) and mid-Cretaceous (ca 110-100 Ma) times, and a possible third episode in the Cenozoic. Denudation commencing in the Late Permian - Early Triassic wins widespread in the eastern and Central Snowy Mountains area, continued through much of the Triassic, and amounted to at least ∼2.0-2,4 km. This episode was probably the geomorphic response to the Hunter-Bowen Orogeny. Post-Triassic denudation to the present in these areas amounted to ∼2.0-2.2 km. Unambiguous evidence for mid-Cretaceous cooling and possible later cooling is confined to a north-south-trending sinuous belt, up to ∼15km wide by at least 35km long, of major reactivated Palaeozoic faults on the western side of the mountains. This zone is the most deeply exposed area of the Kosciuszko block. Denudation accompanying these later events totalled up to ∼1.8-2.0 km and ∼2.0 2.25 km respectively. Mid-Cretaceous denudation marks the onset of renewed tectonic activity in the south-eastern highlands following a period of relative quiescence since the Late Triassic, and establishes a temporal link with the onset of extension related to the opening of the Tasman Sea. Much of the present day relief of the mountains resulted from surface uplift which disrupted the post-mid-Cretaceous apatite fission track profile by variable offsets on faults. Copyright (1999) Geological Society of Australia

Fluids in the Siilinjärvi carbonatite complex, eastern Finland: Fluid inclusion evidence for the formation conditions of zircon and apatite

Directory of Open Access Journals (Sweden)

Poutiainen, M.

1995-06-01

Full Text Available In the studied zircon and apatite crystals, data recorded two different compositional types of fluid inclusions: Type 1 H2O-CO2, low salinity inclusions (XCO2 = 0.42 to 0.87; XNaCl = 0.001 to 0.005 with bulk densities of 0.73 to 0.87 g/cm3, and Type 2 H2O moderate salinity (XNaCl = 0.03 to 0.06 inclusions with densities of 0.83 to 1.02 g/cm3. The Type 1 inclusions are not present in apatite. In zircon, the observed fluid inclusion types occur in separate domains: around (Type 1 and outside (Type 2 the apparent core. Fluid inclusions are further subdivided into pseudosecondary and secondary inclusions. Using a combination of SEM-EDS, optical characteristics and crushing-stage, various daughter and captive minerals were identified. The fluid inclusion data suggest that the pseudosecondary Type 1 and Type 2 inclusions in zircon and apatite were trapped during the pre-emplacement evolution of the carbonatite at mid-crustal conditions (P≥4 kbar, T≥625°C. The Type 1 fluid was depleted in CO2, during crystal fractionation and cooling leading to a fluid phase enriched in water and alkalies. Fenitization was obviously induced by these saline aqueous fluids. During emplacement of the carbonatite to the present level, zircon phenocrysts were intensively fractured, some Type 1 inclusions were re-equilibrated, and multiphase Type 2 inclusions were trapped. It is assumed that all these inclusions in zircon and the pseudosecondary Type 2 inclusions in apatite have a magmatic origin. In apatite, calcite inclusions occur side-by-side with the secondary Type 2 inclusions. These calcites co-existed with the aqueous fluid during fracturing and metamorphic re-crystallization of apatites. Probably, this metamorphic fluid also is responsible for the transport and deposition of at least some of the calcite at low temperatures (200-350°C.

Carbonate substitution in the mineral component of bone: Discriminating the structural changes, simultaneously imposed by carbonate in A and B sites of apatite

Science.gov (United States)

Madupalli, Honey; Pavan, Barbara; Tecklenburg, Mary M. J.

2017-11-01

The mineral component of bone and other biological calcifications is primarily a carbonate substituted calcium apatite. Integration of carbonate into two sites, substitution for phosphate (B-type carbonate) and substitution for hydroxide (A-type carbonate), influences the crystal properties which relate to the functional properties of bone. In the present work, a series of AB-type carbonated apatites (AB-CAp) having varying A-type and B-type carbonate weight fractions were prepared and analyzed by Fourier transform infrared spectroscopy (FTIR), powder X-ray diffraction (XRD), and carbonate analysis. A detailed characterization of A-site and B-site carbonate assignment in the FTIR ν3 region is proposed. The mass fractions of carbonate in A-site and B-site of AB-CAp correlate differently with crystal axis length and crystallite domain size. In this series of samples reduction in crystal domain size correlates only with A-type carbonate which indicates that carbonate in the A-site is more disruptive to the apatite structure than carbonate in the B-site. High temperature methods were required to produce significant A-type carbonation of apatite, indicating a higher energy barrier for the formation of A-type carbonate than for B-type carbonate. This is consistent with the dominance of B-type carbonate substitution in low temperature synthetic and biological apatites.

Project management plan for the gunite and associated tanks treatability studies project at Oak Ridge National Laboratory, Oak Ridge, Tennessee

International Nuclear Information System (INIS)

1995-12-01

This plan for the Gunite and Associated Tanks (GAAT) Treatability Studies Project satisfies the requirements of the program management plan for the Oak Ridge National Laboratory (ORNL) Environmental Restoration (ER) Program as established in the Program Management Plan for the Martin Marietta Energy Systems, Inc., Oak Ridge National Laboratory Site Environmental Restoration Program. This plan is a subtier of several other ER documents designed to satisfy the US Department of Energy (DOE) Order 4700.1 requirement for major systems acquisitions. This project management plan identifies the major activities of the GAAT Treatability Studies Project; establishes performance criteria; discusses the roles and responsibilities of the organizations that will perform the work; and summarizes the work breakdown structure, schedule, milestones, and cost estimate for the project

H-Isotopic Composition of Apatite in Northwest Africa 7034

Science.gov (United States)

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.

Impact of Surface Potential on Apatite Formation in Ti Alloys Subjected to Acid and Heat Treatments.

Science.gov (United States)

Yamaguchi, Seiji; Hashimoto, Hideki; Nakai, Ryusuke; Takadama, Hiroaki

2017-09-24

Titanium metal (Ti) and its alloys are widely used in orthopedic and dental fields. We have previously shown that acid and heat treatment was effective to introduce bone bonding, osteoconduction and osteoinduction on pure Ti. In the present study, acid and heat treatment with or without initial NaOH treatment was performed on typical Ti-based alloys used in orthopedic and dental fields. Dynamic movements of alloying elements were developed, which depended on the kind of treatment and type of alloy. It was found that the simple acid and heat treatment enriched/remained the alloying elements on Ti-6Al-4V, Ti-15Mo-5Zr-3Al and Ti-15Zr-4Nb-4Ta, resulting in neutral surface charges. Thus, the treated alloys did not form apatite in a simulated body fluid (SBF) within 3 days. In contrast, when the alloys were subjected to a NaOH treatment prior to an acid and heat treatment, alloying elements were selectively removed from the alloy surfaces. As a result, the treated alloys became positively charged, and formed apatite in SBF within 3 days. Thus, the treated alloys would be useful in orthopedic and dental fields since they form apatite even in a living body and bond to bone.

Endoscopic treatment of vesicoureteral reflux using calcium hydroxyl apatite in dogs

Directory of Open Access Journals (Sweden)

Tavakoli Azin

2011-01-01

Full Text Available Abstract Background Injection of biomaterial to suburetral region, using minimally invasive procedure, has become an interesting topic for urologists to treat vesicoureteral reflux. The objective of this study was to evaluate the feasibility of injecting newly introduced calcium hydroxyl apatite to suburetral region, for treating an experimentally induced vesicoureteral reflux in dogs. Findings Bilateral vesicoureteral refluxed (VUR mixed breed dogs (n = 12; 10-15 kg live weight, 3-6 months of age were selected for this study. The presence and grade of the reflux were determined using cystography. Accordingly, 6 dogs displayed grade 1 & 2 and the other 6 showed grade 3 & 4 bilateral VUR. Every single dog, with bilateral VUR, underwent endoscopic treatment and received an injection of calcium hydroxyl apatite (an Iranian made product into the left (treated side and an injection of the similar volume of normal saline in to the right (control side subureteric space. One week, 3 and 6 months after treatment, cystography was performed. On each occasion, 4 dogs were euthanized by gas inhalation and biopsy samples were collected for histopathological study from ureter, bladder, kidney, lung and spleen in order to investigate the biomaterial migration into different organs. Data were analyzed using Chi-squared test. In control sides, radiographs confirmed the same grade of VUR, found at the initiation of the study. VUR was resolved in 100% (6/6 of Grade 1 & 2 and 83.33% (5/6 of Grade 3 & 4 in treated side. Therefore, the total success rate of this study was 91.67% (11/12. Macroscopic examination of the vesicouretral region of the treated side revealed a firm and consistent biomaterial mass at the site of injection. Histological findings confirmed inflammation at treated side. In contrast, there was no tissue reaction on control side. There was no evidence for biomaterial migration in macroscopic and microscopic observations in this study. Conclusion In

Contribution to the study of sorption mechanisms at solid-liquid interfaces: application to the cases of apatites and oxy-hydroxides

International Nuclear Information System (INIS)

Duc, M.

2002-11-01

Sorption-desorption phenomena play an important role in the transport of toxic and radioactive elements in surface and underground water in contact with solid matter. Selenium, which is one of the long-lived radionuclides present in radioactive waste, is characterized by several oxidation states and by anionic species in aqueous solutions. In order to predict its transport, we need a good knowledge of its sorption processes. We have studied the sorption of Se(IV) and Se(VI) on two types of solids present in natural media or which have been proposed as additives to active barriers: hydroxy-apatites, fluoro-apatite and iron oxi-hydroxides (goethite and hematite). Sorption mechanisms have been studied through an approach including several different and complementary methods: titrimetry, zeta-metry, scanning and transmission electron microscopy, infrared spectroscopy, X-ray diffraction, X-ray photo electron spectroscopy, etc... Results showed that Se(VI) is much less sorbed than Se(VI) on both types of solids. For Se(IV) the sorption mechanisms are different for iron oxides and apatites. On oxides, sorption increases when pH decreases. It can be interpreted by a surface complexation model, essentially through an inner sphere complex (monodentate or bidentate). Modelling of Se sorption curves was performed after the determination of acido-basic properties of oxides. However, the determination of the intrinsic properties of oxides is disturbed by several parameters identified as impurities, evolution of the solid in solution, kinetic and solubility of the solid. For apatites, selenium sorption proceeds by exchange with superficial groups, with a maximum of fixation at approximately pH 8. Thanks to XPS measurements and the elaboration of a mathematical model, we could determine the depth of penetration of both selenium and cadmium on apatites. (author)

Treatability study of absorbent polymer waste form for mixed waste treatment

International Nuclear Information System (INIS)

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

2000-01-01

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

Apatite fission-track dating of erosion in the eastern Andes, Bolivia

International Nuclear Information System (INIS)

Crough, S.T.

1983-01-01

Three samples from a Triassic-age batholith in the eastern Andes northeast of La Paz, Bolivia yield apatitic fission-track ages of 11-13 Ma. Interpreting these young ages as due to uplift and erosion requires approximately 2.5-5.0 km of erosion in the past 12 Ma, an amount which is consistent with the known geology and which is typical of many active mountain ranges. (orig.)

Using apatite to discriminate synchronous ore-associated and barren granitoid rocks: A case study from the Edong metallogenic district, South China

Science.gov (United States)

Duan, Deng-Fei; Jiang, Shao-Yong

2018-06-01

In order to find criteria to discriminate the synchronous ore-associated and barren granitoid rocks, we have determined apatite chemistry associated with ore-associated (Cu-Au) and barren granitoid rocks in the Edong district of the Middle and Lower Yangtze River metallogenic belt, South China. Both rock types give zircon U-Pb ages between 135.0 and 138.7 Ma. Apatite has a higher volatile and Li content (Cl: 0.19-0.57 wt%, average 0.35 wt%, SO3: 0.08-0.71 wt%, average 0.32 wt%, Li: 0.49-7.99 ppm, average 3.23 ppm) in ore-associated rocks than those in barren rocks (Cl: 0.09-0.31 wt%, average 0.16 wt%, SO3: 0.06-0.28 wt%, average 0.16 wt%, Li: 0.15-0.89 ppm, average 0.36 ppm). Apatite (La/Yb)N ratios and Eu/Eu* values are relatively high and show wider variation in ore-associated rocks than those in barren rocks. Apatite (La/Sm)N and (Yb/Sm)N show positive correlation in ore-associated rocks but negative in barren rocks. The higher volatile content occurs in ore-associated magma, favoring Cu-Au transportation and deposition. Furthermore, amphibole fractional crystallization in ore-associated magma further enriched the ore elements in the residual melt. Barren rocks may have undergone fluid exsolution before emplacement, which makes it barren in Cl, S and ore elements (Cu, S). These signatures emphases the significance of volatile and magma evolution in mineralization and indicate that analyses of magmatic apatite can serve to distinguish ore-associated from barren intrusions.

An ab-initio study of the energetics and geometry of sulfide, sulfite and sulfate incorporation into apatite: The thermodynamic basis for using this system as an oxybarometer

Science.gov (United States)

Kim, Y.; Konecke, B.; Fiege, A.; Simon, A. C.; Becker, U.

2017-12-01

We use ab-initio calculations to investigate the energetics and geometry of incorporation of S with its oxidation states S6+, S4+, and S2- into the apatite end-members fluor-, chlor-, and hydroxylapatite, [Ca10(PO4)6(F,Cl,OH)2]. The reaction energy of the balanced equation indicates the stability of the modeled S-incorporated apatite relative to the host apatite, the source, and sink phases. One possible coupled substitution mechanism involves the replacement of La3+ + PO43- ↔ Ca2+ + SO42-. Our results show that the incorporation of SO42- into La- and Na-bearing apatite, Ca8NaLa(PO4)6(F,Cl,OH)2, is energetically favored over the incorporation into La- and Si-bearing apatite, Ca9La(PO4)5(SiO4)(F,Cl,OH)2. Co-incorporation of SO42- and SO32- is energetically favored when the lone pair electrons of SO32- face towards the anion column site, compared to facing away from it. Full or partial incorporation of S2- is favored on the column anion site in the form of [Ca10(PO4)6S] and [Ca20(PO4)12SX2)], where X = F, Cl, or OH. Upon full incorporation (i.e., replacing all column ions by sulfide ions), S2- is positioned in the anion column at z = 0.5 (half way between the mirror planes at z = 1/4 and z = 3/4) in the energy-optimized structure. The calculated energies for partial incorporation of S2- demonstrate that in an energy-optimized structure, S2- is displaced from the mirror plane at z = 1/4 or 3/4, by 1.0 to 1.6 Å, depending on the surrounding species (F-, Cl- or OH-); however, the probability for S2- to be incorporated into the apatite structure is highest for chlorapatite end-members. Our results describe energetically feasible incorporation mechanisms for all three oxidations states of S (S6+, S4+, S2-) in apatite, along with structural distortion and concurring electronic structure changes. These observations are consistent with recently published experimental results (Konecke et al. 2017) that demonstrate S6+, S4+ and S2- incorporation into apatite, where the

Treatability study work plan for in situ vitrification of seepage pit 1 in Waste Area Grouping 7 at Oak Ridge National Laboratory, Oak Ridge, Tennessee

International Nuclear Information System (INIS)

Spalding, B.P.

1994-07-01

A treatability study is described that encompasses the application of in situ vitrification (ISV) to at least two segments of Oak Ridge National Laboratory (ORNL) seepage pit 1 by the end of fiscal year 1995. This treatability study will 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 overlapping melt settings that are necessary to achieve fused melt segments; (3) demonstrating off-gas handling technology for accommodating and minimizing the volatilization of 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. The initial step of this treatability study will be to gather the required site characterization data about pit 1 so that the in situ vitrification can be effectively and safely planned. The second phase will be the field ISV operations at pit 1 employing at least two settings to achieve overlapping and fused melts. Such field operations are likely to require 6 to 8 weeks. Following termination of ISV melting operations at pit 1 and demobilization of portable ISV equipment and the off-gas hood, posttest characterization activities will begin

Trace Element Geochemistry of Magnetite and Accesory Phases from El Romeral Iron Oxide-Apatite Deposit, Northern Chile

Science.gov (United States)

Barra, F.; Rojas, P.; Reich, M.; Deditius, A.; Simon, A. C.

2017-12-01

Iron oxide-apatite (IOA) or "Kiruna-type" deposits are an important source of Fe, P, REE, among other essential elements for society. Three main hypotheses have been proposed to explain the genesis of these controversial deposits, which invoke liquid immiscibility, hydrothermal replacement or a magmatic-hydrothermal origin driven by flotation of magnetite-bubble pairs. Here we focus on the El Romeral, one of the largest IOA deposits located in the southernmost part of the Cretaceous Chilean Iron Belt. We combined SEM observations and EMPA analyses of magnetite, actinolite, pyrite, and apatite, with micro-Raman determinations of mineral inclusions within magnetite grains. Two textural types of magnetite were identified at El Romeral: (i) inclusion-rich magnetite (Mag I), and (ii) inclusion-poor magnetite (Mag II) that are commonly surrounding the inclusion-rich Mag I grains. Mag I is characterized by high V ( 2500-2800 ppm) and Ti (300-1000 ppm) contents with high-temperature mineral inclusions such as ilmenite, Ti-pargasite and clinochlore at depth, and quartz and phlogopite inclusions in shallower samples. These characteristics are consistent with a magmatic origin for Mag I. Inclusion-poor magnetite (Mag II) have high V (2400-2600 ppm) and lower Ti (70-200 ppm) contents than Mag I, which point to chemical changes of the mineralizing fluid(s). An increase in thermal gradient with depth is evidenced by the presence of high-temperature (low #Fe) actinolite, as well as F-rich apatite and pyrite with high Co:Ni (>1) in the deep zones. In contrast, lower Co:Ni ratios (<0.5) in pyrite and higher Cl contents in OH-rich apatite are detected in samples from shallower levels. This vertical chemical variation supports a magmatic-hydrothermal origin for the El Romeral deposit, and point to compositional changes driven by decompression of a magnetite-fluid suspension.

Chemical, physical, and histologic studies on four commercial apatites used for alveolar ridge augmentation

DEFF Research Database (Denmark)

Pinholt, E M; Ruyter, I E; Haanaes, H R

1992-01-01

The purpose of this study was to evaluate four commercial apatite products. Subperiosteal alveolar ridge augmentation was performed on the maxilla of rats by implantation of granules of two dense products and of two porous products, and the tissue response was compared with the material character...

The shape of ion tracks in natural apatite

Science.gov (United States)

Schauries, D.; Afra, B.; Bierschenk, T.; Lang, M.; Rodriguez, M. D.; Trautmann, C.; Li, W.; Ewing, R. C.; Kluth, P.

2014-05-01

Small angle X-ray scattering measurements were performed on natural apatite of different thickness irradiated with 2.2 GeV Au swift heavy ions. The evolution of the track radius along the full ion track length was estimated by considering the electronic energy loss and the velocity of the ions. The shape of the track is nearly cylindrical, slightly widening with a maximum diameter approximately 30 μm before the ions come to rest, followed by a rapid narrowing towards the end within a cigar-like contour. Measurements of average ion track radii in samples of different thicknesses, i.e. containing different sections of the tracks are in good agreement with the shape estimate.

The shape of ion tracks in natural apatite

International Nuclear Information System (INIS)

Schauries, D.; Afra, B.; Bierschenk, T.; Lang, M.; Rodriguez, M.D.; Trautmann, C.; Li, W.; Ewing, R.C.; Kluth, P.

2014-01-01

Small angle X-ray scattering measurements were performed on natural apatite of different thickness irradiated with 2.2 GeV Au swift heavy ions. The evolution of the track radius along the full ion track length was estimated by considering the electronic energy loss and the velocity of the ions. The shape of the track is nearly cylindrical, slightly widening with a maximum diameter approximately 30 μm before the ions come to rest, followed by a rapid narrowing towards the end within a cigar-like contour. Measurements of average ion track radii in samples of different thicknesses, i.e. containing different sections of the tracks are in good agreement with the shape estimate

Quantitative Identification of the Annealing Degree of Apatite Fission Tracks Using Terahertz Time Domain Spectroscopy (THz-TDS).

Science.gov (United States)

Wu, Hang; Wu, Shixiang; Qiu, Nansheng; Chang, Jian; Bao, Rima; Zhang, Xin; Liu, Nian; Liu, Shuai

2018-01-01

Apatite fission-track (AFT) analysis, a widely used low-temperature thermochronology method, can provide details of the hydrocarbon generation history of source rocks for use in hydrocarbon exploration. The AFT method is based on the annealing behavior of fission tracks generated by 238 U fission in apatite particles during geological history. Due to the cumbersome experimental steps and high expense, it is imperative to find an efficient and inexpensive technique to determinate the annealing degree of AFT. In this study, on the basis of the ellipsoid configuration of tracks, the track volume fraction model (TVFM) is established and the fission-track volume index is proposed. Furthermore, terahertz time domain spectroscopy (THz-TDS) is used for the first time to identify the variation of the AFT annealing degree of Durango apatite particles heated at 20, 275, 300, 325, 450, and 500 ℃ for 10 h. The THz absorbance of the sample increases with the degree of annealing. In addition, the THz absorption index is exponentially related to annealing temperature and can be used to characterize the fission-track volume index. Terahertz time domain spectroscopy can be an ancillary technique for AFT thermochronological research. More work is urgently needed to extrapolate experimental data to geological conditions.

Cellular Adaptation: Culture conditions of R. opacus and bioflotation of apatite and quartz

Directory of Open Access Journals (Sweden)

Antonio Gutiérrez Merma

Full Text Available Abstract It is well known that the culture conditions of microorganisms may affect their surface properties, zeta potential and hydrophobicity via the modification of the cell wall functional groups or metabolic products. The R. opacus bacteria strain was separately adapted to the presence of apatite and quartz, after which a cellular adaptation procedure was developed by repeated sub-culturing with a successive increase in the mineral content. Zeta potential, surface tension, FTIR and microflotation studies were used to evaluate the behavior of the cells that were developed under defined culture conditions. The cellular adaptation induced a modification of the bacterial surface charge. The FTIR results showed a modification of its functional groups. The surface tension results suggested that longer growing time promoted a higher production of metabolites. The use of mineral-adapted cells promoted an improvement in the flotability of both minerals, but it was more significant for apatite flotation. Additionally, the mineral flotability remained unchanged when the cells developed under a longer culture time. Nevertheless, there was a reduction in the surface tension.

Strontium ranelate changes the composition and crystal structure of the biological bone-like apatite produced in osteoblast cell cultures.

Science.gov (United States)

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.

Soil washing physical separations test procedure - 300-FF-1 operable unit

Energy Technology Data Exchange (ETDEWEB)

Belden, R.D.

1993-10-08

This procedure provides the operations approach, a field sampling plan, and laboratory procedures for a soil washing test to be conducted by Alternative Remedial Technologies, Inc. (ART) in the 300-FF-1 area at the Hanford site. The {open_quotes}Quality Assurance Project Plan for the Soil Washing Physical Separations Test, 300-FF-1 Operable Unit,{close_quotes} Hanford, Washington, Alternative Remedial Technologies, Inc., February 1994 (QAPP) is provided in a separate document that presents the procedural and organizational guidelines for this test. This document describes specifications, responsibilities, and general procedures to be followed to conduct physical separation soil treatability tests in the North Process Pond of the 300-FF-1 Operable Unit (OU) at the Hanford Site. These procedures are based on the {open_quotes}300-FF-1 Physical Separations CERCLA Treatability Test Plan, DOE/RL 92-2l,{close_quotes} (DOE-RL 1993).

Soil washing physical separations test procedure - 300-FF-1 operable unit

International Nuclear Information System (INIS)

Belden, R.D.

1993-01-01

This procedure provides the operations approach, a field sampling plan, and laboratory procedures for a soil washing test to be conducted by Alternative Remedial Technologies, Inc. (ART) in the 300-FF-1 area at the Hanford site. The open-quotes Quality Assurance Project Plan for the Soil Washing Physical Separations Test, 300-FF-1 Operable Unit,close quotes Hanford, Washington, Alternative Remedial Technologies, Inc., February 1994 (QAPP) is provided in a separate document that presents the procedural and organizational guidelines for this test. This document describes specifications, responsibilities, and general procedures to be followed to conduct physical separation soil treatability tests in the North Process Pond of the 300-FF-1 Operable Unit (OU) at the Hanford Site. These procedures are based on the open-quotes 300-FF-1 Physical Separations CERCLA Treatability Test Plan, DOE/RL 92-2l,close quotes (DOE-RL 1993)

Phosphorous availability influences the dissolution of apatite by soil fungi

Science.gov (United States)

Rosling, A.; Suttle, K. B.; Johansson, E.; van Hees, P. W.; Banfield, J. F.

2007-12-01

We conducted mineral dissolution experiments using fungi isolated from a grassland soil in northern California to determine the response of fungi to different levels of phosphorus availability and to identify pathways of apatite dissolution by fungal exudates. Fluorapatite dissolution experiments were performed either with fungi present or under abiotic conditions using cell-free liquid media conditioned by fungal growth at different phosphorus and calcium availabilities. Among biogeochemically active soil fungal isolates apatite dissolution was either active in response to phosphorus limiting growth conditions or passive as a result of mycelial growth. Zygomycete isolates in the order of Mucorales acidify their growth media substrate in the presence of phosphorus, mainly through production of oxalic acid. Cell-free exudates induced fluorapatite dissolution at a rate of 10 -0.9 ± 0.14 and 10 -1.2 ± 0.22 mmol P/m2/s. The Ascomycete isolate, in the family Trichocomaceae, induced fluorapatite dissolution at a rate of 10 - 1.1 ± 0.05 mmol P/m2/s by lowering the pH of the media under phosphorus-limited conditions, without producing significant amounts of low molecular weight organic acids (LMWOAs). Oxalate strongly etches fluorapatite along channels parallel to [001], forming needle like features, while exudates from Trichocomaceae induced surface rounding. We conclude that while LMWOAs are well-studied weathering agents these does not appear to be produced by fungi in response to phosphorus limiting growth conditions.

Magmatic apatite - a window into melt evolution of the Dalgety pluton.

Science.gov (United States)

Pope, M. D.; Tailby, N.; Webster, J. D.

2017-12-01

The Dalgety Pluton is located in the Lachlan Fold Belt in southeastern Australia, and is a coarse grained, peraluminous, S-type, biotite granodiorite. Historically, pluton emplacement has been thought of as cooling from a single, large body of magma over a geologically quick period. Current studies suggest issues with this model and propose a slower, incremental model of emplacement in some settings (Glazner et al., 2004). This work proposes that the emplacement of the Dalgety Pluton occurred in incremental phases demonstrated through halogen, minor, and trace element concentrations in apatites. Apatites from 13 samples collected along a north-south transect of the pluton were analyzed using a 5-spectrometer Cameca SX-100 calibrated for seventeen elements (F, Na, Cl, P, Mg, Al, Si, Ca, S, K, Ti, Mn, Fe, Sr, Ba, La, and Ce) at the American Museum of Natural History. The majority of apatites are fluorapatites, having >50 % F, <15 % Cl, and <25 % OH (calculated from Ketchum et al., 2015). However, the concentrations of the halogens vary throughout the pluton with the highest Cl concentrations near the southern edge. Two of the minor elements, Mn and Fe, also show distinct variation with the lowest concentrations being 0.35 wt% in Mn and 0.25 wt% in Fe and the highest being 1.10 wt% and 0.95 wt%, respectively. Trace elements Ce and La vary as well with their highest concentrations being 0.29 wt% and 0.11 wt% and their lowest for both being below the detection limit of the electron probe. Elemental variation across the pluton is seen in the concentration of minor elements and halogens with a sharp increases at 10,000 meters and again at 21,000 meters from the southern rim of the pluton. Similar shifts in concentration are also seen in the trace elements, however the concentrations decrease at these distances. These wholesale elemental fluctuations in composition are indicative of a dramatic shift in melt composition supporting the hypothesis of multiple melt injection

Neonatal screening for treatable congenital disorders

International Nuclear Information System (INIS)

Charoensiriwatana, W.; Janejai, N.; Boonwanich, W.; Krasao, P.; Waiyasilp, S.

2001-01-01

Congenital hypothyroidism is a treatable disease if detected at the early stage of life. It is one of the most frequent cause of mental retardation in children. In 85 % of cases, congenital hypothyroidism is a consequence of thyroid disgenesis, in which the gland is either absent, located ectopically and/or severely reduced in size. Early detection and treatment with thyroid hormone supplement can significantly reduce mental damage. In 1996, Thailand initiated a neonatal screening programme for congenital hypothyroidism (CHT) and phenylketonuria (PKU), with the objective of bringing a better quality of life to people throughout the country, but especially in the remote areas. The programme involves implementing routine screening nationwide. The plan of action was designed with the goal of having public health service units throughout the country provide neonatal screening by year 2002 for the 1.2 million babies born per annum in Thailand. The government supported the programme by allocating a five-year budget of approximately US$15 million. The programme received additional assistance through technical support and human resource development from the International Atomic Energy Agency (IAEA) and the US Centers for Disease Control. This assistance promoted self-sustainability and strengthened the programme's technical base. The programme is on track. It is expected that by year 2002 all new born babies in Thailand will be screened for CHT and PKU

Evaluation of Plasma Spray hydroxy Apatite Coatings on Metallic Materials

International Nuclear Information System (INIS)

Take, S.; Mitsul, K.; Kasahara, M.; Sawal, R.; Izawa, S.; Nakayama, M.; Itoi, Y.

2007-01-01

Biocompatible Hydroxy apatite (HAp) coatings on metallic substrate by plasma spray techniques have been developed. Long-term credibility of plasma spray HAp coatings has been evaluated in physiological saline by electrochemical measurements. It was found that the corrosion resistance of SUS316L based HAp/Ti combined coatings was excellent even after more than 10 weeks long-term immersion. It was shown that postal heat treatment improved both the crystallinity and corrosion resistance of HAp. By lowering cooling rate during heat treatment process, less cracks produced in HAp coating layer, which lead to higher credibility of HAp during immersion in physiological saline. The ICP results showed that the dissolution level of substrate metallic ions was low and HAp coatings produced in this research can be acceptable as biocompatible materials. Also, the concentration of dissolved ions from HAp coatings with postal heat treatment was lower compared to those from samples without postal heat treatment. The adherence of HAp coatings with Ti substrate and other mechanical properties were also assessed by three-point bending test. The poor adhesion of HAp coating to titanium substrate can be improved by introducing a plasma spray titanium intermediate layer

Test plan for ISV laboratory-pyrolysis testing

Energy Technology Data Exchange (ETDEWEB)

McAtee, R.E.

1991-09-01

The objective of the laboratory-pyrolysis studies is to obtain information on the high temperature (< 1200{degree}C) degradation and alteration of organic chemicals and materials similar to those found in the Radioactive Waste Management Complex, Pit 9. This test plan describes experimental procedures, sampling and analysis strategy, sampling procedures, sample control, and document management. It addresses safety issues in the experimental apparatus and procedures, personal training, and hazardous waste disposal. Finally, it describes the data quality objectives using the EPA tiered approach to treatability studies to define where research/scoping tests fit into these studies and the EPA analytical levels required for the tests.

100 Area soil washing: Bench scale tests on 116-F-4 pluto crib soil

International Nuclear Information System (INIS)

Field, J.G.

1994-01-01

The Pacific Northwest Laboratory conducted a bench-scale treatability study on a pluto crib soil sample from 100 Area of the Hanford Site. The objective of this study was to evaluate the use of physical separation (wet sieving), treatment processes (attrition scrubbing, and autogenous surface grinding), and chemical extraction methods as a means of separating radioactively-contaminated soil fractions from uncontaminated soil fractions. The soil washing treatability study was conducted on a soil sample from the 116-F-4 Pluto Crib that had been dug up as part of an excavation treatability study. Trace element analyses of this soil showed no elevated concentrations above typically uncontaminated soil background levels. Data on the distribution of radionuclide in various size fractions indicated that the soil-washing tests should be focused on the gravel and sand fractions of the 116-F-4 soil. The radionuclide data also showed that 137 Cs was the only contaminant in this soil that exceeded the test performance goal (TPG). Therefore, the effectiveness of subsequent soil-washing tests for 116-F-4 soil was evaluated on the basis of activity attenuation of 137 Cs in the gravel- and sand-size fractions

100 Area soil washing: Bench scale tests on 116-F-4 pluto crib soil

Energy Technology Data Exchange (ETDEWEB)

Field, J.G.

1994-06-10

The Pacific Northwest Laboratory conducted a bench-scale treatability study on a pluto crib soil sample from 100 Area of the Hanford Site. The objective of this study was to evaluate the use of physical separation (wet sieving), treatment processes (attrition scrubbing, and autogenous surface grinding), and chemical extraction methods as a means of separating radioactively-contaminated soil fractions from uncontaminated soil fractions. The soil washing treatability study was conducted on a soil sample from the 116-F-4 Pluto Crib that had been dug up as part of an excavation treatability study. Trace element analyses of this soil showed no elevated concentrations above typically uncontaminated soil background levels. Data on the distribution of radionuclide in various size fractions indicated that the soil-washing tests should be focused on the gravel and sand fractions of the 116-F-4 soil. The radionuclide data also showed that {sup 137}Cs was the only contaminant in this soil that exceeded the test performance goal (TPG). Therefore, the effectiveness of subsequent soil-washing tests for 116-F-4 soil was evaluated on the basis of activity attenuation of {sup 137}Cs in the gravel- and sand-size fractions.

Application of apatite fission tract analysis to problems of Mississippi Valley-type Pb-Zn ore genesis

International Nuclear Information System (INIS)

Arne, D.C.; Duddy, I.R.; Green, P.F.; Lambert, I.B.

1987-01-01

Epigenetic, carbonate-hosted Pb-Zn mineralization of the Mississippi Valley-Type (MVT) is considered to form from warm basinal brines in the temperature range 50-200 deg.C. A variety of genetic fluid flow models have been proposed to explain MVT mineralization, but all suffer from a lack of constraint concerning the timing of ore formation. Fission tracks in apatite resulting from the spontaneous decay of trace amounts of 238 U are thermally unstable over the range of temperatures proposed for MVT ore formation, and may therefore record thermal events related to Pb-Zn mineralization provided sufficient time is allowed for track annealing to occur. Zinc mineralization in Devonian carbonates of the Lennard Shelf, northwest Australia is also considered to be of the Mississippi Valley-type. Mean apatite ages from Precambrian basement and from Devonian carbonates generally average 300Ma. Studies of well sequences indicate a period of uplift for the Lennard Shelf area around the Late Triassic/Early Jurassic. For carbonate outcrop samples, a thermal history is proposed involving burial in the Late Paleozoic/Early Mesozoic followed by uplift and cooling from peak temperatures around 70 deg.C. No difference in apatite annealing effects are observed in the vicinity of zinc mineralization. Coupled with other evidence, this suggests that the mineralizing episode was of short duration given temperatures of ore formation in the range 70-110 deg.C indicated by fluid inclusion homogenization temperatures. 3 refs

Screening apatites for (U-Th)/He thermochronometry via continuous ramped heating: He age components and implications for age dispersion

Science.gov (United States)

McDannell, Kalin T.; Zeitler, Peter K.; Janes, Darwin G.; Idleman, Bruce D.; Fayon, Annia K.

2018-02-01

Old slowly-cooled apatites often yield dispersed (U-Th)/He ages for a variety of reasons, some well understood and some not. Analytical protocols like careful grain selection can reduce the impact of this dispersion but add costs in time and resources and too often have proven insufficient. We assess a new analytical protocol that utilizes static-gas measurement during continuous ramped heating (CRH) as a means to rapidly screen apatite samples. In about the time required for a conventional total-gas analysis, this method can discriminate between samples showing expected volume-diffusion behavior and those showing anomalous release patterns inconsistent with their direct use in thermochronologic applications. This method also appears able to discriminate between the radiogenic and extraneous 4He fractions released by a sample, potentially allowing ages to be corrected. Well-behaved examples such as the Durango standard and other apatites with good age reproducibility show the expected smooth, sigmoidal gas-release curves predicted for volume diffusion using typical apatite kinetics, with complete exhaustion by ∼900 °C for linear heating at 20 °C/min. Secondary factors such as U and Th zoning and alpha-loss distribution have a relatively minor impact on such profiles. In contrast, samples having greater age dispersion show significant He release in the form of outgassing spikes and He release deferred to higher temperatures. Screening results for a range of samples permit us to assess the degree to which CRH screening can identify misbehaving grains, give insight into the source of extraneous He, and suggest that in some cases it may be possible to correct ages for the presence of such components.

The Columbia River Protection Supplemental Technologies Quality Assurance Project Plan

International Nuclear Information System (INIS)

Fix, Anne

2007-01-01

The U.S. Department of Energy (DOE) has conducted interim groundwater remedial activities on the Hanford Site since the mid-1990s for several groundwater contamination plumes. DOE established the Columbia River Protection Supplemental Technologies Project (Technologies Project) in 2006 to evaluate alternative treatment technologies. The objectives for the technology project are as follows: develop a 300 Area polyphosphate treatability test to immobilize uranium, design and test infiltration of a phosphate/apatite technology for Sr-90 at 100-N, perform carbon tetrachloride and chloroform attenuation parameter studies, perform vadose zone chromium characterization and geochemistry studies, perform in situ biostimulation of chromium studies for a reducing barrier at 100-D, and perform a treatability test for phytoremediation for Sr-90 at 100-N. This document provides the quality assurance guidelines that will be followed by the Technologies Project. This Quality Assurance Project Plan is based on the quality assurance requirements of DOE Order 414.1C, Quality Assurance, and 10 CFR 830, Subpart A--Quality Assurance Requirements as delineated in Pacific Northwest National Laboratory?s Standards-Based Management System. In addition, the technology project is subject to the Environmental Protection Agency (EPA) Requirements for Quality Assurance Project Plans (EPA/240/B-01/003, QA/R-5). The Hanford Analytical Services Quality Assurance Requirements Documents (HASQARD, DOE/RL-96-68) apply to portions of this project and to the subcontractors. HASQARD requirements are discussed within applicable sections of this plan.

δ18O of apatite phosphate in small pelagic fish: insights from wild-caught and tank-grown specimens

Science.gov (United States)

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.

Kinetics of apatite formation on a calcium-silicate cement for root-end filling during ageing in physiological-like phosphate solutions.

Science.gov (United States)

Gandolfi, Maria Giovanna; Taddei, Paola; Tinti, Anna; De Stefano Dorigo, Elettra; Rossi, Piermaria Luigi; Prati, Carlo

2010-12-01

The bioactivity of calcium silicate mineral trioxide aggregate (MTA) cements has been attributed to their ability to produce apatite in presence of phosphate-containing fluids. This study evaluated surface morphology and chemical transformations of an experimental accelerated calcium-silicate cement as a function of soaking time in different phosphate-containing solutions. Cement discs were immersed in Dulbecco's phosphate-buffered saline (DPBS) or Hank's balanced salt solution (HBSS) for different times (1-180 days) and analysed by scanning electron microscopy connected with an energy dispersive X-ray analysis (SEM-EDX) and micro-Raman spectroscopy. SEM-EDX revealed Ca and P peaks after 14 days in DPBS. A thin Ca- and P-rich crystalline coating layer was detected after 60 days. A thicker multilayered coating was observed after 180 days. Micro-Raman disclosed the 965-cm(-1) phosphate band at 7 days only on samples stored in DPBS and later the 590- and 435-cm(-1) phosphate bands. After 60-180 days, a layer approximately 200-900 μm thick formed displaying the bands of carbonated apatite (at 1,077, 965, 590, 435 cm(-1)) and calcite (at 1,088, 713, 280 cm(-1)). On HBSS-soaked, only calcite bands were observed until 90 days, and just after 180 days, a thin apatite-calcite layer appeared. Micro-Raman and SEM-EDX demonstrated the mineralization induction capacity of calcium-silicate cements (MTAs and Portland cements) with the formation of apatite after 7 days in DPBS. Longer time is necessary to observe bioactivity when cements are immersed in HBSS.

Vapor vacuum extraction treatability study at the Idaho National Engineering Laboratory

International Nuclear Information System (INIS)

Herd, M.D.; Matthern, G.; Michael, D.L.; Spang, N.; Downs, W.; Weidner, J.; Cleary, P.

1993-01-01

During the 1960s and early 1970s, barreled mixed waste containing volatile organic compounds (VOCS) and radioactive waste was buried at the Subsurface Disposal Area (SDA) at the Idaho National Engineering Laboratory (INEL) Radioactive Waste Management Complex (RWMC). Over time, some of the barrels have deteriorated allowing, VOC vapors to be released into the vadose zone. The primary VOC contaminates of concern are CCl 4 and trichloroethylene; however, chloroform, tetrachloroethylene, and 1,1,1-trichloroethane have also been detected. Vapor Vacuum Extraction (VVE) is one alternative being considered for remediation of the RWMC SDA vadose zone. A proposed pilot-scale treatability study (TS) will provide operation and maintenance costs for the design of the potential scale-up of the system

Enhanced apatite-forming ability and antibacterial activity of porous anodic alumina embedded with CaO-SiO2-Ag2O bioactive materials.

Science.gov (United States)

Ni, Siyu; Li, Xiaohong; Yang, Pengan; Ni, Shirong; Hong, Feng; Webster, Thomas J

2016-01-01

In this study, to provide porous anodic alumina (PAA) with bioactivity and anti-bacterial properties, sol-gel derived bioactive CaO-SiO2-Ag2O materials were loaded onto and into PAA nano-pores (termed CaO-SiO2-Ag2O/PAA) by a sol-dipping method and subsequent calcination of the gel-glasses. The in vitro apatite-forming ability of the CaO-SiO2-Ag2O/PAA specimens was evaluated by soaking them in simulated body fluid (SBF). The surface microstructure and chemical property before and after soaking in SBF were characterized. Release of ions into the SBF was also measured. In addition, the antibacterial properties of the samples were tested against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). The results showed that CaO-SiO2-Ag2O bioactive materials were successfully decorated onto and into PAA nano-pores. In vitro SBF experiments revealed that the CaO-SiO2-Ag2O/PAA specimens dramatically enhanced the apatite-forming ability of PAA in SBF and Ca, Si and Ag ions were released from the samples in a sustained and slow manner. Importantly, E. coli and S. aureus were both killed on the CaO-SiO2-Ag2O/PAA (by 100%) samples compared to PAA controls after 3 days of culture. In summary, this study demonstrated that the CaO-SiO2-Ag2O/PAA samples possess good apatite-forming ability and high antibacterial activity causing it to be a promising bioactive coating candidate for implant materials for orthopedic applications. Copyright © 2015 Elsevier B.V. All rights reserved.

Experimental study of kinetic and mechanism of dissolution of apatite structured minerals. Application to the prediction of the long term behavior of an actinides storage host matrix

International Nuclear Information System (INIS)

Chairat, C.

2005-11-01

The motivation for this study is to assess the potential of using apatite structured ceramics as long-lived actinide storage hosts. To assess their ability to resist aqueous corrosion, the dissolution of natural fluoro-apatite and synthetic Nd-britholite (neodymium is a proxy for the trivalent actinides) was studied. Mineral surfaces were characterized using a combined spectrometric, electrokinetic and potentiometric approach and dissolution rates were measured in closed and open system reactors as a function of solution composition. Experimental results suggest apatitic minerals dissolve via distinct step sequence: 1) fluoride release, 2) release of the calcium situated in the M1, and 3) the simultaneous removal of phosphate and calcium II via the breaking of only Ca-O bonds. TST based rate equations based in this mechanism accurately describe fluoro-apatite and synthetic britholite dissolution rates as a function of solution composition. Nd release rates are limited by precipitation of Nd-rhabdophane. (author)

A novel simple strategy for in situ deposition of apatite layer on AZ31B magnesium alloy for bone tissue regeneration

Energy Technology Data Exchange (ETDEWEB)

Mousa, Hamouda M. [Department of Bionanosystem Engineering, Chonbuk National University, Jeonju, Jeonbuk 561-756 (Korea, Republic of); Department of Engineering Materials and Mechanical Design, Faculty of Engineering, South Valley University, Qena 83523 (Egypt); Lee, Do Hee [Department of Bionanosystem Engineering, Chonbuk National University, Jeonju, Jeonbuk 561-756 (Korea, Republic of); Park, Chan Hee, E-mail: biochan@jbnu.ac.kr [Department of Bionanosystem Engineering, Chonbuk National University, Jeonju, Jeonbuk 561-756 (Korea, Republic of); Division of Mechanical Design Engineering, Chonbuk National University, Jeonju, Jeonbuk 561-756 (Korea, Republic of); Kim, Cheol Sang, E-mail: chskim@jbnu.ac.kr [Department of Bionanosystem Engineering, Chonbuk National University, Jeonju, Jeonbuk 561-756 (Korea, Republic of); Division of Mechanical Design Engineering, Chonbuk National University, Jeonju, Jeonbuk 561-756 (Korea, Republic of)

2015-10-01

Graphical abstract: - Highlights: • Anodizing process was used for the surface modification of AZ31B magnesium alloy. • An appetite-like film was deposited on the surface of AZ31B magnesium alloy. • Ceramic film was investigated by XRD and XPS. • Nano-plates growth are observed though the implemented experimental design. • Significant increase in the substrate hardness and surface roughness was observed. - Abstract: In this study, for the first time, the degradation performance of AZ31B Mg alloy was tuned by an in situ deposition of apatite thin layer within a short time in one step. Using Taguchi method for experimental design, anodization process was designed under control conditions (time and voltage), and simulated body fluid (SBF) was used as the electrolyte to nucleate apatite-like compounds. The coated alloy was characterized through field emission scanning electron microscopy (FE-SEM), EDS, X-ray diffraction and XPS analysis. The results show that the applied voltage has a significant effect on the formation of apatite-like layers. Compared to the uncoated samples, microhardness and surface roughness of the coated samples showed remarkably different values. The potentiodynamic polarization results demonstrate that the polarization resistance of the anodized samples is higher than the substrate polarization resistance, thus improving the alloy corrosion resistant. Based on the experimental results, the proposed nanostructure apatite-like coating can offer a promising way to improve the biocompatibility and degradability properties of the Mg alloy for bone tissue regeneration.

Apatite/Melt Partitioning Experiments Reveal Redox Sensitivity to Cr, V, Mn, Ni, Eu, W, Th, and U

Science.gov (United States)

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.

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

Directory of Open Access Journals (Sweden)

Valentina Imperatore

2016-02-01

Full Text Available 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.

Effect of Alkali-Acid-Heat Chemical Surface Treatment on Electron Beam Melted Porous Titanium and Its Apatite Forming Ability.

Science.gov (United States)

Bsat, Suzan; Yavari, Saber Amin; Munsch, Maximilian; Valstar, Edward R; Zadpoor, Amir A

2015-04-08

Advanced additive manufacturing techniques such as electron beam melting (EBM), can produce highly porous structures that resemble the mechanical properties and structure of native bone. However, for orthopaedic applications, such as joint prostheses or bone substitution, the surface must also be bio-functionalized to promote bone growth. In the current work, EBM porous Ti6Al4V alloy was exposed to an alkali acid heat (AlAcH) treatment to bio-functionalize the surface of the porous structure. Various molar concentrations (3, 5, 10M) and immersion times (6, 24 h) of the alkali treatment were used to determine optimal parameters. The apatite forming ability of the samples was evaluated using simulated body fluid (SBF) immersion testing. The micro-topography and surface chemistry of AlAcH treated samples were evaluated before and after SBF testing using scanning electron microscopy and energy dispersive X-ray spectroscopy. The AlAcH treatment successfully modified the topographical and chemical characteristics of EBM porous titanium surface creating nano-topographical features ranging from 200-300 nm in size with a titania layer ideal for apatite formation. After 1 and 3 week immersion in SBF, there was no Ca or P present on the surface of as manufactured porous titanium while both elements were present on all AlAcH treated samples except those exposed to 3M, 6 h alkali treatment. An increase in molar concentration and/or immersion time of alkali treatment resulted in an increase in the number of nano-topographical features per unit area as well as the amount of titania on the surface.

Effect of Alkali-Acid-Heat Chemical Surface Treatment on Electron Beam Melted Porous Titanium and Its Apatite Forming Ability

Directory of Open Access Journals (Sweden)

Suzan Bsat

2015-04-01

Full Text Available Advanced additive manufacturing techniques such as electron beam melting (EBM, can produce highly porous structures that resemble the mechanical properties and structure of native bone. However, for orthopaedic applications, such as joint prostheses or bone substitution, the surface must also be bio-functionalized to promote bone growth. In the current work, EBM porous Ti6Al4V alloy was exposed to an alkali acid heat (AlAcH treatment to bio-functionalize the surface of the porous structure. Various molar concentrations (3, 5, 10M and immersion times (6, 24 h of the alkali treatment were used to determine optimal parameters. The apatite forming ability of the samples was evaluated using simulated body fluid (SBF immersion testing. The micro-topography and surface chemistry of AlAcH treated samples were evaluated before and after SBF testing using scanning electron microscopy and energy dispersive X-ray spectroscopy. The AlAcH treatment successfully modified the topographical and chemical characteristics of EBM porous titanium surface creating nano-topographical features ranging from 200–300 nm in size with a titania layer ideal for apatite formation. After 1 and 3 week immersion in SBF, there was no Ca or P present on the surface of as manufactured porous titanium while both elements were present on all AlAcH treated samples except those exposed to 3M, 6 h alkali treatment. An increase in molar concentration and/or immersion time of alkali treatment resulted in an increase in the number of nano-topographical features per unit area as well as the amount of titania on the surface.

In situ Sr/Sr investigation of igneous apatites and carbonates using laser-ablation MC-ICP-MS

DEFF Research Database (Denmark)

Bizzarro, Martin; Simonetti, A.; Stevenson, R.K.

2003-01-01

In situ Sr isotopic compositions of coexisting apatite and carbonate for carbonatites from the Sarfartoq alkaline complex, Greenland, have been determined by laser-ablation multicollector inductively coupled plasma mass spectrometry. This study is the first to examine the extent of Sr isotopic ho...

Behaviors of MC3T3-E1 cells on carbonated apatite films, with a characteristic network structure, fabricated on a titanium plate by aqueous spray coating

International Nuclear Information System (INIS)

Mochizuki, Chihiro; Hara, Hiroki; Oya, Kei; Aoki, Shun; Hayakawa, Tohru; Fujie, Hiromichi; Sato, Mitsunobu

2014-01-01

Four carbonated apatite films having average thicknesses of 1.3–0.11 μm, proportions of network sizes above 10 μm of 41–68%, and average border heights of the characteristic network structure of 0.98–0.29 μm were fabricated on a titanium plate by aqueous spray coating. These carbonated apatite films after heat treatment showed good mineralization ability in Hanks' balanced salt solution. Assessment of initial cell attachment and calcination on these films and on the Ti plate using osteoblastic MC3T3-E1 indicated that the carbonated apatite film heat treated at 600 °C, whose film thickness, proportion of network sizes above 10 μm, and border height were 0.11 μm, 61%, and 0.31 μm, respectively, was most preferred by osteoblastic cells. Field emission scanning electron microscopic observation of the cells attached to the films showed that the wide network and low border height of the network structure on the carbonated apatite film play an important role in the development of the filopodia of the osteoblastic cells. - Highlights: • Osteoblastic MC3T3-E1 behaviors on aqueous spray coating-derived carbonated apatite (CA) films • The network size of CA films is important. • CA films having a low network border height are better for cell proliferation

Behaviors of MC3T3-E1 cells on carbonated apatite films, with a characteristic network structure, fabricated on a titanium plate by aqueous spray coating

Energy Technology Data Exchange (ETDEWEB)

Mochizuki, Chihiro; Hara, Hiroki [Division of Liberal Arts, Kogakuin University, 2665-1 Nakano, Hachioji, Tokyo 192-0015 (Japan); Oya, Kei [Research Institute for Science and Technology, Kogakuin University, 2665-1 Nakano, Hachioji, Tokyo 192-0015 (Japan); School of Engineering, Tokai University, 4-1-1 Kitakanane, Hiratsuka, Kanagawa 259-1292 (Japan); Aoki, Shun [Faculty of System Design, Tokyo Metropolitan University, 6-6 Asahigaoka, Hino, Tokyo 191-0065 (Japan); Hayakawa, Tohru [Department of Dental Engineering, Tsurumi University School of Dental Medicine, 2-1-3 Tsurumi, Yokohama City, Kanagawa 230-8501 (Japan); Fujie, Hiromichi [Faculty of System Design, Tokyo Metropolitan University, 6-6 Asahigaoka, Hino, Tokyo 191-0065 (Japan); Sato, Mitsunobu, E-mail: lccsato@cc.kogakuin.ac.jp [Division of Liberal Arts, Kogakuin University, 2665-1 Nakano, Hachioji, Tokyo 192-0015 (Japan)

2014-06-01

Four carbonated apatite films having average thicknesses of 1.3–0.11 μm, proportions of network sizes above 10 μm of 41–68%, and average border heights of the characteristic network structure of 0.98–0.29 μm were fabricated on a titanium plate by aqueous spray coating. These carbonated apatite films after heat treatment showed good mineralization ability in Hanks' balanced salt solution. Assessment of initial cell attachment and calcination on these films and on the Ti plate using osteoblastic MC3T3-E1 indicated that the carbonated apatite film heat treated at 600 °C, whose film thickness, proportion of network sizes above 10 μm, and border height were 0.11 μm, 61%, and 0.31 μm, respectively, was most preferred by osteoblastic cells. Field emission scanning electron microscopic observation of the cells attached to the films showed that the wide network and low border height of the network structure on the carbonated apatite film play an important role in the development of the filopodia of the osteoblastic cells. - Highlights: • Osteoblastic MC3T3-E1 behaviors on aqueous spray coating-derived carbonated apatite (CA) films • The network size of CA films is important. • CA films having a low network border height are better for cell proliferation.

Strontium isotope systematics of scheelite and apatite from the Felbertal tungsten deposit, Austria - results of in-situ LA-MC-ICP-MS analysis

Science.gov (United States)

Kozlik, Michael; Gerdes, Axel; Raith, Johann G.

2016-02-01

The in-situ Sr isotopic systematics of scheelite and apatite from the Felbertal W deposit and a few regional Variscan orthogneisses ("Zentralgneise") have been determined by LA-MC-ICP-MS. The 87Sr/86Sr ratios of scheelite and apatite from the deposit are highly radiogenic and remarkably scattering. In the early magmatic-hydrothermal scheelite generations (Scheelite 1 and 2) the 87Sr/86Sr ratios range from 0.72078 to 0.76417 and from 0.70724 to 0.76832, respectively. Metamorphic Scheelite 3, formed by recrystallisation and local mobilisation of older scheelite, is characterised by even higher 87Sr/86Sr values between 0.74331 and 0.80689. Statistics allows discriminating the three scheelite generations although there is considerable overlap between Scheelite 1 and 2; they could be mixtures of the same isotopic reservoirs. The heterogeneous and scattering 87Sr/86Sr ratios of the two primary scheelite generations suggest modification of the Sr isotope system due to fluid-rock interaction and isotopic disequilibrium. Incongruent release of 87Sr from micas in the Early Palaeozoic host rocks of the Habach Complex contributed to the solute budget of the hydrothermal fluids and may explain the radiogenic Sr isotope signature of scheelite. Spatially resolved analyses revealed isotopic disequilibrium even on a sub-mm scale within zoned Scheelite 2 crystals indicating scheelite growth in an isotopic dynamical hydrothermal system. Zoned apatite from the W mineralised Early Carboniferous K1-K3 orthogneiss in the western ore field yielded 87Sr/86Sr of 0.72044-0.74514 for the cores and 0.74535-0.77937 for the rims. Values of magmatic apatite cores from the K1-K3 orthogneiss are comparable to those of primary Scheelite 1; they are too radiogenic to be magmatic. The Sr isotopic composition of apatite cores was therefore equally modified during the hydrothermal mineralisation processes, therefore supporting the single-stage genetic model in which W mineralisation is associated with

Effect of strontium addition and chitosan concentration variation on cytotoxicity of chitosan-alginate-carbonate apatite based bone scaffold

Science.gov (United States)

Perkasa, Rilis Eka; Umniati, B. Sri; Sunendar, Bambang

2017-09-01

Bone scaffold is one of the most important component in bone tissue engineering. Basically, bone scaffold is a biocompatible structure designed to replace broken bone tissue temporarily. Unlike conventional bone replacements, an advanced bone scaffold should be bioactive (e.g: supporting bone growth) and biodegradable as new bone tissue grow, while retain its mechanical properties similarity with bone. It is also possible to add more bioactive substrates to bone scaffold to further support its performance. One of the substrate is strontium, an element that could improve the ability of the bone to repair itself. However, it must be noted that excessive consumption of strontium could lead to toxicity and diseases, such as osteomalacia and hypocalcemia. This research aimed to investigate the effect of strontium addition to the cytotoxic property of chitosan-alginate-carbonate apatite bone scaffold. The amount of strontium added to the bone scaffold was 5% molar of the carbonate apatite content. As a control, bone scaffold without stronsium (0% molar) were also made. The effect of chitosan concentration variation on the cytotoxicity were also observed, where the concentration varies on 1% and 3% w/v of chitosan solution. The results showed an optimum result on bone scaffold sample with 5% molar of strontium and 3% chitosan, where 87.67% cells in the performed MTS-Assay cytotoxicity testing survived. This showed that the use of up to 5% molar addition of strontium and 3% chitosan could enhance the survivability of the cell.

Preparation and properties of calcium-silicate filled resins for dental restoration. Part I: chemical-physical characterization and apatite-forming ability.

Science.gov (United States)

Profeta, Andrea Corrado

2014-11-01

The aim of this study was to measure dimensional changes due to hygroscopic expansion and the bioactivity of two experimental methacrylate-based dental adhesives either incorporating Bioglass 45S5 (3-E&RA/BG) or MTA (3-E&RA/WMTA). 3-E&RA/BG, 3-E&RA/WMTA and a control filler-free resin blend (3-E&RA) were formulated from commercially available monomers. Water sorption (WS) and solubility (SL) behaviour were evaluated by weighing material disks at noted intervals; the relationship between degree of hydration and the glass transition temperature (Tg) was investigated by using differential scanning calorimetry (DSC). In vitro apatite-forming ability as a function of soaking time in phosphate-containing solutions was also determined. Kruskal-Wallis analysis of variance (ANOVA) was used to evaluate differences between groups for maximum WS, SL, net water uptake and the percentage change in Tg values. Post-ANOVA pair-wise comparisons were conducted using Mann-Whitney-U tests. 3-E&RA/BG and 3-E&RA/WMTA exhibited values of maximum WS and net water uptake that were significantly higher when compared to 3-E&RA. However, no statistically significant differences were observed in terms of SL between all the adhesives. The addition of the Bioglass 45S5 and MTA to the 3-E&RA showed no reduction of the Tg after 60 days of storage in deionized water. ATR Fourier Transform Infrared Spectroscopy (ATR-FTIR) of the filled resin disks soaked in DPBS for 60 days showed the presence of carbonate ions in different chemical phases. Dentine bonding agents comprising calcium-silicates are not inert materials in a simulated oral environment and apatite formation may occur in the intra-oral conditions. A bioactive dental material which forms apatite on the surface would have several benefits including closure of gaps forming at the resin-dentine interface and potentially better bond strength over time (less degradation of bond).

The Thermal Evolution of the Southeast Baffin Island Continental Margin: An Integrated Apatite Fission Track and Apatite (U-Th)/He Study

Science.gov (United States)

Jess, S.; Stephenson, R.; Brown, R. W.

2017-12-01

The elevated continental margins of the North Atlantic continue to be a focus of considerable geological and geomorphological debate, as the timing of major tectonic events and the age of topographic relief remain controversial. The West Greenland margin, on the eastern flank of Baffin Bay, is believed by some authors to have experienced tectonic rejuvenation and uplift during the Neogene. However, the opposing flank, Baffin Island, is considered to have experienced a protracted erosional regime with little tectonic activity since the Cretaceous. This work examines the thermal evolution of the Cumberland Peninsula, SE Baffin Island, using published apatite fission track (AFT) data with the addition of 103 apatite (U-Th)/He (AHe) ages. This expansion of available thermochronological data introduces a higher resolution of thermal modelling, whilst the application of the newly developed `Broken Crystals' technique provides a greater number of thermal constraints for an area dominated by AHe age dispersion. Results of joint thermal modelling of the AFT and AHe data exhibit two significant periods of cooling across the Cumberland Peninsula: Devonian/Carboniferous to the Triassic and Late Cretaceous to present. The earliest phase of cooling is interpreted as the result of major fluvial systems present throughout the Paleozoic that flowed across the Canadian Shield to basins in the north and south. The later stage of cooling is believed to result from rift controlled fluvial systems that flowed into Baffin Bay during the Mesozoic and Cenozoic during the early stages and culmination of rifting along the Labrador-Baffin margins. Glaciation in the Late Cenozoic has likely overprinted these later river systems creating a complex fjordal distribution that has shaped the modern elevated topography. This work demonstrates how surface processes, and not tectonism, can explain the formation of elevated continental margins and that recent methodological developments in the field of

Biomineral processing of high apatite containing low-grade indian uranium ore

International Nuclear Information System (INIS)

Abhilash; Mehta, K.D.; Pandey, B.D.; Ray, L.; Tamrakar, P.K.

2010-01-01

Microbial species isolated from source mine water, primarily an enriched culture of Acidithiobacillus ferrooxidans was employed for bio-leaching of uranium from a low-grade apatite rich uranium ore of Narwapahar Mines, India while varying pH, pulp density (PD), particle size, etc. The ore (0.047% U_3O_8), though of Singhbhum area (richest deposit of uranium ores in India), due to presence of some refractory minerals and high apatite (5%) causes a maximum 78% recovery through conventional processing. Bioleaching experiments were carried out by varying pH at 35"oC using 20%(w/v) PD and <76μm size particles resulting in 83.5% and 78% uranium bio-recovery at 1.7 and 2.0 pH in 40 days as against maximum recovery of 46% and 41% metal in control experiments respectively. Finer size (<45μm) ore fractions exhibited higher uranium dissolution (96%) in 40 days at 10% (w/v) pulp density (PD), 1.7 pH and 35"oC. On increasing the pulp density from 10% to 20% under the same conditions, the biorecovery of uranium fell down from 96% to 82%. The higher uranium dissolution during bioleaching at 1.7 pH with the fine size particles (<45μm) can be correlated with increase in redox potential from 598 mV to 708 mV and the corresponding variation of Fe(III) ion concentration in 40 days. (author)

Development of nanosized silver-substituted apatite for biomedical applications: A review.

Science.gov (United States)

Lim, Poon Nian; Chang, Lei; Thian, Eng San

2015-08-01

The favorable biocompatibility of hydroxyapatite (HA) makes it a popular bone graft material as well as a coating layer on metallic implant. To reduce implant-related infections, silver ions were either incorporated into the apatite during co-precipitation process (AgHA-CP) or underwent ion-exchange with the calcium ions in the apatite (AgHA-IE). However, the distribution of silver ions in AgHA-CP and AgHA-IE was different, thus affecting the antibacterial action. Several studies reported that nanosized AgHA-CP containing 0.5 wt.% of silver provided an optimal trade-off between antibacterial properties and cytotoxicity. Nevertheless, nanosized AgHA and AgHA nanocoatings could not function ideally due to the compromise in the bone differentiation of mesenchymal stem cells, as evidenced in the reduced alkaline phosphatase, type I collagen and osteocalcin. Preliminary studies showed that biological responses of nanosized AgHA and AgHA nanocoatings could be improved with the addition of silicon. This review will discuss on nanosized AgHA and AgHA nanocoatings. In many patients needing bone graft material, hydroxyapatite (HA) has proven to be a popular choice. Nonetheless, implant-related infections remain a major concern. Hence, effective preventive measures are needed. In this review article, the authors discussed the application of incorporating silver nanoparticles in HA and its use as bone graft biomaterials together with the addition of silica. Copyright © 2015 Elsevier Inc. All rights reserved.

Mg substituted apatite coating from alkali conversion of acidic calcium phosphate

Energy Technology Data Exchange (ETDEWEB)

Navarro da Rocha, Daniel, E-mail: dnr.navarro@gmail.com [Military Institute of Engineering-IME, Pça. Gen. Tiburcio, 80, P. Vermelha, Urca, Rio de Janeiro, R.J. (Brazil); Cruz, Leila Rosa de Oliveira [Military Institute of Engineering-IME, Pça. Gen. Tiburcio, 80, P. Vermelha, Urca, Rio de Janeiro, R.J. (Brazil); Campos, José Brant de [Rio de Janeiro State University - UERJ, Rio de Janeiro, R.J. (Brazil); Marçal, Rubens L. Santana Blazutti [Military Institute of Engineering-IME, Pça. Gen. Tiburcio, 80, P. Vermelha, Urca, Rio de Janeiro, R.J. (Brazil); Mijares, Dindo Q.; Coelho, Paulo G. [Department of Biomaterials and Biomimetics, New York University College of Dentistry (NYU), New York, NY (United States); Prado da Silva, Marcelo H. [Military Institute of Engineering-IME, Pça. Gen. Tiburcio, 80, P. Vermelha, Urca, Rio de Janeiro, R.J. (Brazil)

2017-01-01

In this work, two solutions were developed: the first, rich in Ca{sup 2+}, PO{sub 4}{sup 3−} ions and the second, rich in Ca{sup 2+}, PO{sub 4}{sup 3−} and Mg{sup 2+}, defined as Mg-modified precursor solution. For each Mg-modified precursor solution, the concentrations of Mg{sup 2+} ions were progressively increased by 5%, 10% and 15%wt. The aims of this research were to investigate the influence of magnesium ions substitution in calcium phosphate coatings on titanium surface and to evaluate these coatings by bioactivity assay in McCoy culture medium. The obtained coatings were characterized by X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) analysis, and the presence of Mg ions was confirmed by the inductively coupled plasma atomic emission spectroscopy (ICP) analysis. In vitro bioactivity assay in McCoy culture medium showed bioactivity after 14 days in incubation for the HA and 10% Mg-monetite coatings. The high chemical stability of Mg-HA coatings was verified by the bioactivity assays, and no bone-like apatite deposition, characteristic of bioactivity, was observed for Mg-HA coatings, for the time period used in this study. - Highlights: • The presence of Mg ions influenced the final apatite phase present in the produced coatings. • A lower efficiency in heterogeneous deposition and an exposure of Ti substrate in 5% Mg-monetite coatings was soon verified. • McCoy culture medium was effective in predicting the coatings bioactivity.

Biomineral processing of high apatite containing low-grade indian uranium ore

Energy Technology Data Exchange (ETDEWEB)

Abhilash; Mehta, K.D.; Pandey, B.D., E-mail: biometnml@gmail.com [National Metallurgical Laboratory (CSIR), Jamshedpur (India); Ray, L. [Jadavpur Univ., FTBE Dept., Kolkata (India); Tamrakar, P.K. [Uranium Corp. of India Limited, CR& D Dept., Jaduguda (India)

2010-07-01

Microbial species isolated from source mine water, primarily an enriched culture of Acidithiobacillus ferrooxidans was employed for bio-leaching of uranium from a low-grade apatite rich uranium ore of Narwapahar Mines, India while varying pH, pulp density (PD), particle size, etc. The ore (0.047% U{sub 3}O{sub 8}), though of Singhbhum area (richest deposit of uranium ores in India), due to presence of some refractory minerals and high apatite (5%) causes a maximum 78% recovery through conventional processing. Bioleaching experiments were carried out by varying pH at 35{sup o}C using 20%(w/v) PD and <76μm size particles resulting in 83.5% and 78% uranium bio-recovery at 1.7 and 2.0 pH in 40 days as against maximum recovery of 46% and 41% metal in control experiments respectively. Finer size (<45μm) ore fractions exhibited higher uranium dissolution (96%) in 40 days at 10% (w/v) pulp density (PD), 1.7 pH and 35{sup o}C. On increasing the pulp density from 10% to 20% under the same conditions, the biorecovery of uranium fell down from 96% to 82%. The higher uranium dissolution during bioleaching at 1.7 pH with the fine size particles (<45μm) can be correlated with increase in redox potential from 598 mV to 708 mV and the corresponding variation of Fe(III) ion concentration in 40 days. (author)

Abnormal arrangement of a collagen/apatite extracellular matrix orthogonal to osteoblast alignment is constructed by a nanoscale periodic surface structure.

Science.gov (United States)

Matsugaki, Aira; Aramoto, Gento; Ninomiya, Takafumi; Sawada, Hiroshi; Hata, Satoshi; Nakano, Takayoshi

2015-01-01

Morphological and directional alteration of cells is essential for structurally appropriate construction of tissues and organs. In particular, osteoblast alignment is crucial for the realization of anisotropic bone tissue microstructure. In this article, the orientation of a collagen/apatite extracellular matrix (ECM) was established by controlling osteoblast alignment using a surface geometry with nanometer-sized periodicity induced by laser ablation. Laser irradiation induced self-organized periodic structures (laser-induced periodic surface structures; LIPSS) with a spatial period equal to the wavelength of the incident laser on the surface of biomedical alloys of Ti-6Al-4V and Co-Cr-Mo. Osteoblast orientation was successfully induced parallel to the grating structure. Notably, both the fibrous orientation of the secreted collagen matrix and the c-axis of the produced apatite crystals were orientated orthogonal to the cell direction. To the best of our knowledge, this is the first report demonstrating that bone tissue anisotropy is controllable, including the characteristic organization of a collagen/apatite composite orthogonal to the osteoblast orientation, by controlling the cell alignment using periodic surface geometry. Copyright © 2014 Elsevier Ltd. All rights reserved.

Citrate- and Succinate-Modified Carbonate Apatite Nanoparticles with Loaded Doxorubicin Exhibit Potent Anticancer Activity against Breast Cancer Cells

Directory of Open Access Journals (Sweden)

Sultana Mehbuba Hossain

2018-03-01

Full Text Available Biodegradable inorganic apatite-based particle complex is popular for its pH-sensitivity at the endosomal acidic environment to facilitate drug release following cellular uptake. Despite being a powerful anticancer drug, doxorubicin shows severe off-target effects and therefore would need a carrier for the highest effectiveness. We aimed to chemically modify carbonate apatite (CA with Krebs cycle intermediates, such as citrate and succinate in order to control the growth of the resultant particles to more efficiently carry and transport the anticancer drug into the cancer cells. Citrate- or succinate-modified CA particles were synthesized with different concentrations of sodium citrate or sodium succinate, respectively, in the absence or presence of doxorubicin. The drug loading efficiency of the particles and their cellular uptake were observed by quantifying fluorescence intensity. The average diameter and surface charge of the particles were determined using Zetasizer. Cell viability was assessed by MTT assay. Citrate-modified carbonate apatite (CMCA exhibited the highest (31.38% binding affinity for doxorubicin and promoted rapid cellular uptake of the drug, leading to the half-maximal inhibitory concentration 1000 times less than that of the free drug in MCF-7 cells. Hence, CMCA nanoparticles with greater surface area enhance cytotoxicity in different breast cancer cells by enabling higher loading and more efficient cellular uptake of the drug.

Iron and oxygen isotope signatures of the Pea Ridge and Pilot Knob magnetite-apatite deposits, southeast Missouri, USA

Science.gov (United States)

Childress, Tristan; Simon, Adam C.; Day, Warren C.; Lundstrom, Craig C.; Bindeman, Ilya N.

2016-01-01

New O and Fe stable isotope ratios are reported for magnetite samples from high-grade massive magnetite of the Mesoproterozoic Pea Ridge and Pilot Knob magnetite-apatite ore deposits and these results are compared with data for other iron oxide-apatite deposits to shed light on the origin of the southeast Missouri deposits. The δ18O values of magnetite from Pea Ridge (n = 12) and Pilot Knob (n = 3) range from 1.0 to 7.0 and 3.3 to 6.7‰, respectively. The δ56Fe values of magnetite from Pea Ridge (n = 10) and Pilot Knob (n = 6) are 0.03 to 0.35 and 0.06 to 0.27‰, respectively. These δ18O and the δ56Fe values suggest that magnetite crystallized from a silicate melt (typical igneous δ56Fe ranges 0.06–0.49‰) and grew in equilibrium with a magmatic-hydrothermal aqueous fluid. We propose that the δ18O and δ56Fe data for the Pea Ridge and Pilot Knob magnetite-apatite deposits are consistent with the flotation model recently proposed by Knipping et al. (2015a), which invokes flotation of a magmatic magnetite-fluid suspension and offers a plausible explanation for the igneous (i.e., up to ~15.9 wt % TiO2 in magnetite) and hydrothermal features of the deposits.

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

International Nuclear Information System (INIS)

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

Biomimetic scaffolds based on hydroxyapatite nanorod/poly(D,L) lactic acid with their corresponding apatite-forming capability and biocompatibility for bone-tissue engineering.

Science.gov (United States)

Nga, Nguyen Kim; Hoai, Tran Thanh; Viet, Pham Hung

2015-04-01

This study presents a facile synthesis of biomimetic hydroxyapatite nanorod/poly(D,L) lactic acid (HAp/PDLLA) scaffolds with the use of solvent casting combined with a salt-leaching technique for bone-tissue engineering. Field emission scanning electron microscopy, Fourier transform infrared spectroscopy, and energy-dispersive X-ray spectroscopy were used to observe the morphologies, pore structures of synthesized scaffolds, interactions between hydroxyapatite nanorods and poly(D,L) lactic acid, as well as the compositions of the scaffolds, respectively. Porosity of the scaffolds was determined using the liquid substitution method. Moreover, the apatite-forming capability of the scaffolds was evaluated through simulated body fluid (SBF) incubation tests, whereas the viability, attachment, and distribution of human osteoblast cells (MG 63 cell line) on the scaffolds were determined through alamarBlue assay and confocal laser microscopy after nuclear staining with 4',6-diamidino-2-phenylindole and actin filaments of a cytoskeleton with Oregon Green 488 phalloidin. Results showed that hydroxyapatite nanorod/poly(D,L) lactic acid scaffolds that mimic the structure of natural bone were successfully produced. These scaffolds possessed macropore networks with high porosity (80-84%) and mean pore sizes ranging 117-183 μm. These scaffolds demonstrated excellent apatite-forming capabilities. The rapid formation of bone-like apatites with flower-like morphology was observed after 7 days of incubation in SBFs. The scaffolds that had a high percentage (30 wt.%) of hydroxyapatite demonstrated better cell adhesion, proliferation, and distribution than those with low percentages of hydroxyapatite as the days of culture increased. This work presented an efficient route for developing biomimetic composite scaffolds, which have potential applications in bone-tissue engineering. Copyright © 2015 Elsevier B.V. All rights reserved.

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

International Nuclear Information System (INIS)

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

1996-01-01

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

Using the chemical analysis of magnetite to constrain various stages in the formation and genesis of the Kiruna-type chadormalu magnetite-apatite deposit, Bafq district, Central Iran

Science.gov (United States)

Heidarian, Hassan; Lentz, David; Alirezaei, Saeed; Peighambari, Sima; Hall, Douglas

2016-12-01

Textural and compositional data are presented for different types of magnetite in the Chadormalu iron deposit to discern the genesis of various styles of mineralization. Samples were chosen according to their paragenetic relations to apatite and their host setting: magnetite-apatite veins in the altered host rocks, disseminated magnetite-apatite assemblages in the marginal parts of the main ore body, and massive magnetite associated with irregular apatite veinlets from internal part of the main ore body. Scanning electron microscopy - back scatter electron (SEM-BSE) images reveal that there are three main generations of magnetite in each of the different magnetite-apatite assemblages. Primary magnetite (Mag1) features abundant porosity and a dark appearance. A second generation of magnetite (Mag2) replacing Mag1 shows a lighter appearance with both sharp and gradational contacts with the primary magnetite crystals. The two magnetite types are related to dissolution-precipitation processes due to changing physico-chemical parameters of the ore fluids. A third type of magnetite (Mag3) with a recrystallized appearance and foam-like triple junctions was mostly observed in magnetite-apatite veins in the main ore body and in veins hosted by altered rocks. Electron probe microanalyses (EPMA) were utilized to discriminate the various magnetite generations in the different magnetite-apatite assemblages. Applying published elemental discrimination diagrams shows that most primary magnetites fall into the hydrothermal- and Kiruna-type fields. Primary magnetite contains lower FeO (88.77-93.65 wt.%; average 91.5 wt.%), and higher SiO2 (0.21-2.26 wt.%; ave. 0.32 wt.%), Al2O3 (0.001-0.45 wt.%; ave. 0.053 wt.%), and CaO (0.002-0.48 wt.%; ave. 0.078 wt.%) contents, which might be related to magmatically derived fluids. Secondary magnetites have higher FeO (89.23-93.49 wt.%; ave. 92.11 wt.%), lower SiO2 (0.037-0.189 wt.%; ave. 0.072 wt.%), Al2O3 (0.004-0.072 wt.%; ave. 0.019 wt

SUPERFUND TREATABILITY CLEARINGHOUSE: FULL SCALE ROTARY KILN INCINERATOR FIELD TRIAL: PHASE I, VERIFICATION TRIAL BURN ON DIOXIN/HERBICIDE ORANGE CONTAMINATED SOIL

Science.gov (United States)

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...

Treatability and scale-up protocols for polynuclear aromatic hydrocarbon bioremediation of manufactured-gas-plant soils. Final report, September 1987-July 1991

International Nuclear Information System (INIS)

Blackburn, J.W.; DiGrazia, P.M.; Sanseverino, J.

1991-07-01

The report describes activities to develop a framework to reliably scale-up and apply challenging bioremediation processes to polynuclear aromatic hydrocarbons in Manufactured Gas Plant (MGP) soils. It includes: a discussion of the accuracy needed for competitive application of bioremediation; a framework and examples for treatability and scale-up protocols for selection, design and application of these processes; both batch and continuous testing protocols for developing predictive rate data; and special predictive relationships that may be used in process selection/scale-up. The work, coupled with subsequent work (as recommended) to develop an MGP soil desorption/diffusion protocol and new scale-up methods, and with subsequent scale-up testing should lead to the capability for improved selection of MGP sites for bioremediation and improved performance, success, and reliability of field applications. With this greater predictive reliability, bioremediation will be used more often in the field on the most favorable applications and its cost advantages over other remediation options will be realized

Understanding the uplift pattern in Mesozoic and Cenozoic,, eastern Dabie area, China using fission track dating of apatite

International Nuclear Information System (INIS)

Wu Qianhong; Liu Shunsheng

2002-01-01

By using the fission track dating technique, a preliminary study was carried out on the fission track ages (FTA) of apatite, their distribution patterns and hints over the tectonics activities during Mesozoic and Cenozoic in the east Dabie area. Attempts were also made to improve the conventional statistical method for the tracks. Ranging from 59.4 +- 3.4 Ma to 105.6 +- 9.8 Ma, the FTA results of apatite spread in the wide range and increased rapidly from the east to the west area. Sine 95 Ma, the uplift rate has been quite slow and asymmetry. The FTA value in the middle area of Xiaotian-Mozitan Fault may imply its uplift in Cretaceous. The faulting should be the main control factor for the uplift of this area

Alternate dipping preparation of biomimetic apatite layers in the presence of carbonate ions

International Nuclear Information System (INIS)

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

2014-01-01

The classical simulated body fluids method cannot be employed to prepare biomimetic apatites encompassing metallic ions that lead to very stable phosphates. This is the case for heavy metals such as uranium, whose presence in bone mineral after contamination deserves toxicological study. We have demonstrated that existing methods, based on alternate dipping into calcium and phosphate ions solutions, can be adapted to achieve this aim. We have also especially studied the impact of the presence of carbonate ions in the medium as these are necessary to avoid hydrolysis of the contaminating metallic cations. Both the apatite–collagen complex method and a standard chemical (STD) method employing only mineral solutions lead to biomimetic apatites when calcium and carbonate ions are introduced simultaneously. The obtained materials were fully characterized and we established that the STD method tolerates the presence of carbonate ions much better, and this leads to homogeneous samples. Emphasis was set on the repeatability of the method to ensure the relevancy of further work performed on series of samples. Finally, osteoblasts cultured on these samples also proved a similar yield and standard-deviation in their adenosine triphosphate content when compared to commercially available substrates designed to study of such cell cultures. (paper)

Bony defect repair in rabbit using hybrid rapid prototyping polylactic co glycolic acid/β tricalciumphosphate collagen I/apatite scaffold and bone marrow mesenchymal stem cells

Directory of Open Access Journals (Sweden)

Long Pang

2013-01-01

Full Text Available Background: In bone tissue engineering, extracellular matrix exerts critical influence on cellular interaction with porous biomaterial and the apatite playing an important role in the bonding process of biomaterial to bone tissue. The aim of this study was to observe the therapeutic effects of hybrid rapid prototyping (RP scaffolds comprising polylactic-co-glycolic acid (PLGA, β-tricalciumphosphate (β-TCP, collagen I and apatite (PLGA/β-TCP-collagen I/apatite on segmental bone defects in conjunction with combination with bone marrow mesenchymal stem cells (BMSCs. Materials and Methods: BMSCs were seeded into the hybrid RP scaffolds to repair 15 mm defect in the radius of rabbits. Radiograph, microcomputed tomography and histology were used to evaluate new bone formation. Results: Radiographic analysis done from 12 to 36 weeks postoperative period demonstrated that new bone formed at the radial defect site and continues to increase until the medullary cavity is recanalized and remodelling is complete. The bone defect remained unconnected in the original RP scaffolds (PLGA/β-TCP during the whole study. Histological observations conformed to the radiographic images. In hybrid RP scaffold group, woven bone united the radial defect at 12 weeks and consecutively remodeled into lamellar bone 24 weeks postoperation and finally matured into cortical bone with normal marrow cavity after another 12 weeks. No bone formation but connective tissue has been detected in RP scaffold at the same time. Conclusion: Collagen I/apatite sponge composite coating could improve new bone formation in vivo. The hybrid RP scaffold of PLGA/β-TCP skeleton with collagen I/apatite sponge composite coating is a promising candidate for bone tissue engineering.

Role of endorectal MR imaging and MR spectroscopic imaging in defining treatable intraprostatic tumor foci in prostate cancer: Quantitative analysis of imaging contour compared to whole-mount histopathology

International Nuclear Information System (INIS)

Anwar, Mekhail; Westphalen, Antonio C.; Jung, Adam J.; Noworolski, Susan M.; Simko, Jeffry P.; Kurhanewicz, John; Roach, Mack; Carroll, Peter R.; Coakley, Fergus V.

2014-01-01

Purpose: To investigate the role of endorectal MR imaging and MR spectroscopic imaging in defining the contour of treatable intraprostatic tumor foci in prostate cancer, since targeted therapy requires accurate target volume definition. Materials and methods: We retrospectively identified 20 patients with prostate cancer who underwent endorectal MR imaging and MR spectroscopic imaging prior to radical prostatectomy and subsequent creation of detailed histopathological tumor maps from whole-mount step sections. Two experienced radiologists independently reviewed all MR images and electronically contoured all suspected treatable (⩾0.5 cm 3 ) tumor foci. Deformable co-registration in MATLAB was used to calculate the margin of error between imaging and histopathological contours at both capsular and non-capsular surfaces and the treatment margin required to ensure at least 95% tumor coverage. Results: Histopathology showed 17 treatable tumor foci in 16 patients, of which 8 were correctly identified by both readers and an additional 2 were correctly identified by reader 2. For all correctly identified lesions, both readers accurately identified that tumor contacted the prostatic capsule, with no error in contour identification. On the non-capsular border, the median distance between the imaging and histopathological contour was 1.4 mm (range, 0–12). Expanding the contour by 5 mm at the non-capsular margin included 95% of tumor volume not initially covered within the MR contour. Conclusions: Endorectal MR imaging and MR spectroscopic imaging can be used to accurately contour treatable intraprostatic tumor foci; adequate tumor coverage is achieved by expanding the treatment contour at the non-capsular margin by 5 mm

Magnetic apatite for structural insights on the plasma membrane

International Nuclear Information System (INIS)

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

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. (paper)

Magnetic apatite for structural insights on the plasma membrane

Science.gov (United States)

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.

Hydrogen Isotopic Composition of Apatite in Northwest Africa 7034: A Record of the "Intermediate" H-Isotopic Reservoir in the Martian Crust?

Science.gov (United States)

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 visible-infrared reflectance spectra of the martian surface measured from orbit [2]. The composition of the fine-grained matrix within NWA 7034 bears a striking resemblance to the major element composition estimated for the martian crust, with several exceptions. The NWA 7034 matrix is depleted in Fe, Ti, and Cr and enriched in Al, Na, and P [3]. The differences in Al and Fe are the most substantial, but the Fe content of NWA 7034 matrix falls within the range reported for the southern highlands crust [6]. It was previously suggested by [4] that NWA 7034 was sourced from the southern highlands based on the ancient 4.4 Ga ages recorded in NWA 7034/7533 zircons [4, 5]. In addition, the NWA 7034 matrix material is enriched in incompatible trace elements by a factor of 1.2-1.5 [7] relative to estimates of the bulk martian crust. The La/Yb ratio of the bulk martian crust is estimated to be approximately 3 [7], and the La/Yb of the NWA 7034 matrix materials ranges from approximately 3.9 to 4.4 [3, 8], indicating a higher degree of LREE enrichment in the NWA 7034 matrix materials. This elevated La/Yb ratio and enrichment in incompatible lithophile trace elements is consistent with NWA 7034 representing a more geochemically enriched crustal terrain than is represented by the bulk martian crust, which would be expected if NWA 7034 represents the bulk crust from the southern highlands. Given the similarities between NWA 7034 and the martian crust, NWA 7034 may represent an important sample for constraining the composition of the martian crust, particularly the ancient highlands. In the present study, we seek to constrain the H isotopic composition of the martian crust using Cl-rich apatite in NWA 7034. Usui et al., [9] recently proposed that a H isotopic reservoir exists within the martian crust that has

Treatability studies in support of the nonradiological wastewater treatment project

Energy Technology Data Exchange (ETDEWEB)

Begovich, J.M.; Brown, C.H. Jr.; Villiers-Fisher, J.F.; Fowler, V.L.

1986-07-01

The Nonradiological Wastewater Treatment Project (NRWTP) will treat nonradiological wastewaters generated at the Oak Ridge National Laboratory (ORNL) to pollutant levels acceptable under restrictions imposed by the effluent limits of best available technology (BAT) regulations of the US Environmental Protection Agency (EPA), according to the goals established by the Clean Water Act. A three-phase treatability study was conducted to resolve many of the uncertainties facing the NRWTP. The first phase consisted of batch simulation of the proposed NRWTP flowsheet in the laboratory. The Phase I results revealed no major problems with the proposed flowsheet. Phase II consisted of more-detailed parametric studies of the flowsheet processes at a bench-scale level in the laboratory. The Phase II results were used to guide the planning and design of the Phase III study, which consisted of flowsheet simulation on a continuous basis using a mini-pilot plant (MPP) facility. This facility is contained within two connected semitrailer vans and an analytical trailer.

Production and in vitro characterization of 3D porous scaffolds made of magnesium carbonate apatite (MCA)/anionic collagen using a biomimetic approach

International Nuclear Information System (INIS)

Sader, Marcia S.; Martins, Virginia C.A.; Gomez, Santiago; LeGeros, Racquel Z.; Soares, Gloria A.

2013-01-01

3D porous scaffolds are relevant biomaterials to bone engineering as they can be used as templates to tissue reconstruction. The aim of the present study was to produce and characterize in vitro 3D magnesium-carbonate apatite/collagen (MCA/col) scaffolds. They were prepared by using biomimetic approach, followed by cross-linking with 0.25% glutaraldehyde solution (GA) and liofilization. Results obtained with Fourier-transform infrared spectroscopy (FT-IR) confirmed the type-B carbonate substitution, while by X-ray diffraction (XRD), a crystallite size of ∼ 10 nm was obtained. Optical and electron microscopy showed that the cylindrical samples exhibited an open-porous morphology, with apatite nanocrystals precipitated on collagen fibrils. The cross-linked 3D scaffolds showed integrity when immersed in culture medium up to 14 days. Also, the immersion of such samples into an acid buffer solution, to mimic the osteoclastic resorption environment, promotes the release of important ions for bone repair, such as calcium, phosphorus and magnesium. Bone cells (SaOs2) adhered, and proliferated on the 3D composite scaffolds, showing that synthesis and the cross-linking processes did not induce cytotoxicity. Highlights: • 3D scaffolds of Mg-carbonate–apatite and anionic-collagen were produced. • The biomimetic approach and the cross-linking with 0.25% GA solution were employed. • The scaffolds showed open-porous structure and apatite crystals on collagen fibrils. • The cross-linked scaffolds exhibited integrity when immersed in culture medium. • SaOs2 cells adhered and proliferated on the cross-linked scaffolds confirming no cytotoxicity

Production and in vitro characterization of 3D porous scaffolds made of magnesium carbonate apatite (MCA)/anionic collagen using a biomimetic approach

Energy Technology Data Exchange (ETDEWEB)

Sader, Marcia S., E-mail: msader@metalmat.ufrj.br [Prog. Engenharia Metalúrgica e Materiais, COPPE/UFRJ, RJ (Brazil); Martins, Virginia C.A. [Depto. de Química e Física Molecular, IQSC/USP, SP (Brazil); Gomez, Santiago [Dept. Anatomía Patológica, Universidad de Cádiz, Cadiz (Spain); LeGeros, Racquel Z. [Department of Biomaterials and Biomimetics, New York University College of Dentistry, NY (United States); Soares, Gloria A. [Prog. Engenharia Metalúrgica e Materiais, COPPE/UFRJ, RJ (Brazil)

2013-10-15

3D porous scaffolds are relevant biomaterials to bone engineering as they can be used as templates to tissue reconstruction. The aim of the present study was to produce and characterize in vitro 3D magnesium-carbonate apatite/collagen (MCA/col) scaffolds. They were prepared by using biomimetic approach, followed by cross-linking with 0.25% glutaraldehyde solution (GA) and liofilization. Results obtained with Fourier-transform infrared spectroscopy (FT-IR) confirmed the type-B carbonate substitution, while by X-ray diffraction (XRD), a crystallite size of ∼ 10 nm was obtained. Optical and electron microscopy showed that the cylindrical samples exhibited an open-porous morphology, with apatite nanocrystals precipitated on collagen fibrils. The cross-linked 3D scaffolds showed integrity when immersed in culture medium up to 14 days. Also, the immersion of such samples into an acid buffer solution, to mimic the osteoclastic resorption environment, promotes the release of important ions for bone repair, such as calcium, phosphorus and magnesium. Bone cells (SaOs2) adhered, and proliferated on the 3D composite scaffolds, showing that synthesis and the cross-linking processes did not induce cytotoxicity. Highlights: • 3D scaffolds of Mg-carbonate–apatite and anionic-collagen were produced. • The biomimetic approach and the cross-linking with 0.25% GA solution were employed. • The scaffolds showed open-porous structure and apatite crystals on collagen fibrils. • The cross-linked scaffolds exhibited integrity when immersed in culture medium. • SaOs2 cells adhered and proliferated on the cross-linked scaffolds confirming no cytotoxicity.

Application of neutron activation analysis to control P2O5 content in ore and ore concentrates of ''Apatit'' works

International Nuclear Information System (INIS)

Belyakov, M.A.; Terent'eV, Eh.P.; Frolov, V.A.

1982-01-01

A technique for a neutron activation rapid analysis of fluorine is described. A mean-square error of the analysis makes up 0,g3 per cent F. The investigation has been carried out and a close correlation has been established for the Hibine massif exploited apatite deposits on the basis of the neutron activation analysis of fluorine and chemical analysis of P 2 O 5 . Possibilities are shown of using the neutron activation analysis of P 2 O 5 in ores and certain ore con-- centrates of ''Apatit'' works from the radioactivity induced in fluorine. A mean-square error of the analysis makes up 0,35 per cent P 2 O 5

The effect of ZrO2 and TiO 2 on solubility and strength of apatite-mullite glass-ceramics for dental applications.

Science.gov (United States)

Fathi, Hawa M; Miller, Cheryl; Stokes, Christopher; Johnson, Anthony

2014-03-01

The effect of ZrO2 and TiO2 on the chemical and mechanical properties of apatite-mullite glass-ceramics was investigated after sample preparation according to the ISO (2768:2008) recommendations for dental ceramics. All materials were characterized using differential thermal analysis, X-ray diffraction, scanning electron microscopy and energy dispersive spectroscopy. X-ray fluorescence spectroscopy was used to determine the concentrations of elements present in all materials produced. The chemical solubility test and the biaxial flexural strength (BFS) test were then carried out on all the samples. The best solubility value of 242 ± 61 μg/cm(2) was obtained when HG1T was heat-treated for 1 h at the glass transition temperature plus 20 °C (Tg + 20 °C) followed by 5 h at 1200 °C. The highest BFS value of 174 ± 38 MPa was achieved when HG1Z and HG1Z+T were heat-treated for 1 h at the Tg + 20 °C followed by 7 h at 1200 °C. The present study has demonstrated that the addition of TiO2 to the reference composition showed promise in both the glass and heat-treated samples. However, ZrO2 is an effective agent for developing the solubility or the mechanical properties of an apatite-mullite glass-ceramic separately but does not improve the solubility and the BFS simultaneously.

Risk score for identifying adults with CSF pleocytosis and negative CSF Gram stain at low risk for an urgent treatable cause

NARCIS (Netherlands)

Hasbun, Rodrigo; Bijlsma, Merijn; Brouwer, Matthijs C.; Khoury, Nabil; Hadi, Christiane M.; van der Ende, Arie; Wootton, Susan H.; Salazar, Lucrecia; Hossain, Md Monir; Beilke, Mark; van de Beek, Diederik

2013-01-01

We aimed to derive and validate a risk score that identifies adults with cerebrospinal fluid (CSF) pleocytosis and a negative CSF Gram stain at low risk for an urgent treatable cause. Patients with CSF pleocytosis and a negative CSF Gram stain were stratified into a prospective derivation (n = 193)

Revisiting the localization of Zn2+ cations sorbed on pathological apatite calcifications made through X-ray absorption spectroscopy

Energy Technology Data Exchange (ETDEWEB)

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.

Study of damage and helium diffusion in fluoro-apatites; Etude de l'endommagement et de la diffusion de l'helium dans des fluoroapatites

Energy Technology Data Exchange (ETDEWEB)

Miro, S

2004-12-15

This work lies within the scope of the study of the radionuclides containment matrices. The choice of the fluoro-apatites as potential matrices of containment was suggested by the notable properties of these latter (thermal and chemical stability even under radioactive radiation). By irradiations with heavy ions and a helium implantation we simulated the effects related to the alpha radioactivity and to the spontaneous nuclear fission of the radionuclides. Thanks to the study of Durango fluoro-apatite single crystals and fluoro-apatite sintered ceramics, we evidenced that the damage fraction as well as the unit cell deformations increase with the electronic energy loss and with the substitution. These effects are followed at high fluences by a phenomenon of re-crystallization. The study of the helium diffusion points out that the thermal diffusion process improves with the substitution and strongly increases with heavy ions irradiation. (author)

Mechanism and Kinetics for the Dissolution of Apatitic Materials in Acid Solutions

Directory of Open Access Journals (Sweden)

Calmanovici C.E.

1997-01-01

Full Text Available Abstract - This work concerns the study of the digestion step in the production process of phosphoric acid. Some qualitative experiments indicate that the difference between the pH at the surface of the phosphate and that in the bulk of the solution is negligible and that the dissolution is controlled by diffusion of products away from the phosphate particle. In further experiments, to isolate the dissolution phenomenon from the formation of calcium sulfate, the sulfuric acid normally used industrially is replaced by hydrochloric acid. The phosphate material used in our experiments is a model apatitic material: synthetic hydroxyapatite (HAP. The dissolution of calcium hydroxyapatite was studied with increasing amounts of calcium and phosphate at different temperatures. A simple method was developed for this observation based on the time required for complete dissolution of the HAP powder. The results confirm that the dissolution is controlled by a diffusional process through an interface of calcium and phosphate ions released from the solid surface. A kinetic model for the dissolution of apatitic materials is proposed which assumes a shrinking particle behaviour controlled by diffusion of calcium ions. The experimental results are fitted to this model to determine the mass transfer constant for HAP dissolution in acid solutions. The activation energy of the reaction is about 14kJ/mol. This study was carried on in conditions similar to the industrial ones for the production of phosphoric acid by the dihydrate-process

Effect of surface silanol groups on the deposition of apatite onto silica surfaces: a computer simulation study

CSIR Research Space (South Africa)

Mkhonto, D

2008-01-01

Full Text Available the surface silicon and oxygen species rearrange to form O–Si–O links. Any dangling silicon and oxygen bonds at the silica surfaces are saturated by coordination to oxygen and calcium atoms in the apatite layer, but the extra reactivity afforded by these under...

Effect of ozonation on the biological treatability of a textile mill effluent.

Science.gov (United States)

Karahan, O; Dulkadiroglu, H; Kabdasli, I; Sozen, S; Babuna, F Germirli; Orhon, D

2002-12-01

Ozonation applied prior to biological processes, has proved to be a very effective chemical treatment step mostly for colour removal when soluble dyes are used in textile finishing operations. Its impact on biological treatability however has not been fully evaluated yet. This study evaluates the effect of ozonation on the quality of wastewater from a textile mill involving bleaching and reactive dyeing of cotton and synthetic knit fabric. The effect of ozonation on COD fractionation and kinetic coefficients defining major biological processes is emphasised. The results indicate that the extent of ozone applied greatly affects the remaining organic carbon composition in the wastewater. The relative magnitude of different COD fractions varies as a function of the ozone dose. Ozonation does not however exert a measurable impact on the rate of major biological processes.

Local structure and oxide-ion conduction mechanism in apatite-type lanthanum silicates.

Science.gov (United States)

Masson, Olivier; Berghout, Abid; Béchade, Emilie; Jouin, Jenny; Thomas, Philippe; Asaka, Toru; Fukuda, Koichiro

2017-01-01

The local structure of apatite-type lanthanum silicates of general formula La 9.33+x (SiO 4 ) 6 O 2+3x/2 has been investigated by combining the atomic pair distribution function (PDF) method, conventional X-ray and neutron powder diffraction (NPD) data and density functional theory (DFT) calculations. DFT was used to build structure models with stable positions of excess oxide ions within the conduction channel. Two stable interstitial positions were obtained in accordance with literature, the first one located at the very periphery of the conduction channel, neighbouring the SiO 4 tetrahedral units, and the second one closer to the channel axis. The corresponding PDFs and average structures were then calculated and tested against experimental PDFs obtained by X-ray total scattering and NPD Rietveld refinements results gathered from literature. It was shown that of the two stable interstitial positions obtained with DFT only the second one located within the channel is consistent with experimental data. This result consolidates one of the two main conduction mechanisms along the c-axis reported in the literature, namely the one involving cooperative movement of O4 and Oi ions.

Remediation of lead, cadmium and uranium contaminated water and soil by apatite amendment

International Nuclear Information System (INIS)

Raicevic, S.; Plecas, I.; Kaludjerovic, T.

2002-01-01

During the past years as a consequence of war and some accidents in neighboring countries large areas in Serbia were contaminated by toxic heavy metals, including lead, cadmium and uranium. For example, the concentrations of Pb, Cd, Cu and Cr have been doubled above the allowed maximum value in the Romanian part of the Danube while sediments near the border in Bulgaria have higher concentrations of Pb 3 times, Cu 1400 times and Cd 30 times more than the average long-standing levels. Furthermore, an estimated 10 tons of depleted uranium (DU) was spread mainly throughout the territory of Kosovo. This contamination is a potential source of different chronic diseases including malignant diseases and represents a long-term threat for the population living in the affected areas. For this reason, remediation of contaminated sites represents an urgent need and priority. The standard remediation procedure which includes soil removal, treatment (washing, chelating), conditioning etc. is costly, disruptive and not sustainable. This study was carried out to evaluate apatite from the Lisina deposit as soil amendment for in situ stabilization of toxic heavy metals. Preliminary theoretical and experimentally results presented here point out this natural apatite as an ecological, nontoxic material which can be used for efficient and cost-effective remediation of large areas contaminated with Pb, Cd and U. (author)

Preparation and biocompatibility evaluation of apatite/wollastonite-derived porous bioactive glass ceramic scaffolds

International Nuclear Information System (INIS)

Zhang Hua; Ye Xiaojian; Li Jiashun

2009-01-01

An apatite/wollastonite-derived (A/W) porous glass ceramic scaffold with highly interconnected pores was successfully fabricated by adding a plastic porosifier. The morphology, porosity and mechanical strength were characterized. The results showed that the glass ceramic scaffold with controllable pore size and porosity displayed open macropores. In addition, good in vitro bioactivity was found for the scaffold obtained by soaking it in simulated body fluid. Mesenchymal stem cells (MSCs) were cultured, expanded and seeded on the scaffold, and the adhesion and proliferation of MSCs were determined using MTT assay and environmental scanning electron microscopy (ESEM). The results revealed that the scaffold was biocompatible and had no negative effects on the MSCs in vitro. The in vivo biocompatibility and osteogenicity were investigated by implanting both the pure scaffold and the MSC/scaffold construct in rabbit mandibles and studying histologically. The results showed that the glass ceramic scaffold exhibited good biocompatibility and osteoconductivity. Moreover, the introduction of MSCs into the scaffold observably improved the efficiency of new bone formation, especially at the initial stage after implantation. However, the glass ceramic scaffold showed the same good biocompatibility and osteogenicity as the hybrid one at the later stage. These results indicate that porous bioactive scaffolds based on the original apatite-wollastonite glass ceramic fulfil the basic requirements of a bone tissue engineering scaffold.

Apatite formation on bioactive calcium-silicate cements for dentistry affects surface topography and human marrow stromal cells proliferation.

Science.gov (United States)

Gandolfi, Maria Giovanna; Ciapetti, Gabriela; Taddei, Paola; Perut, Francesca; Tinti, Anna; Cardoso, Marcio Vivan; Van Meerbeek, Bart; Prati, Carlo

2010-10-01

The effect of ageing in phosphate-containing solution of bioactive calcium-silicate cements on the chemistry, morphology and topography of the surface, as well as on in vitro human marrow stromal cells viability and proliferation was investigated. A calcium-silicate cement (wTC) mainly based on dicalcium-silicate and tricalcium-silicate was prepared. Alpha-TCP was added to wTC to obtain wTC-TCP. Bismuth oxide was inserted in wTC to prepare a radiopaque cement (wTC-Bi). A commercial calcium-silicate cement (ProRoot MTA) was tested as control. Cement disks were aged in DPBS for 5 h ('fresh samples'), 14 and 28 days, and analyzed by ESEM/EDX, SEM/EDX, ATR-FTIR, micro-Raman techniques and scanning white-light interferometry. Proliferation, LDH release, ALP activity and collagen production of human marrow stromal cells (MSC) seeded for 1-28 days on the cements were evaluated. Fresh samples exposed a surface mainly composed of calcium-silicate hydrates CSH (from the hydration of belite and alite), calcium hydroxide, calcium carbonate, and ettringite. Apatite nano-spherulites rapidly precipitated on cement surfaces within 5 h. On wTC-TCP the Ca-P deposits appeared thicker than on the other cements. Aged cements showed an irregular porous calcium-phosphate (Ca-P) coating, formed by aggregated apatite spherulites with interspersed calcite crystals. All the experimental cements exerted no acute toxicity in the cell assay system and allowed cell growth. Using biochemical results, the scores were: fresh cements>aged cements for cell proliferation and ALP activity (except for wTC-Bi), whereas fresh cementsapatite nano-spherulites; (2) the alpha-TCP doped cement aged for 28 days displayed the highest bioactivity and cell proliferation; (3) the deleterious effect of bismuth on cell

An early cretaceous phase of accelerated erosion on the south-western margin of Africa: evidence from apatite fission track analysis and the offshore sedimentary record

International Nuclear Information System (INIS)

Brown, R.W.; Gleadow, A.J.W.; Rust, D.J.; Summerfield, M.A.; De Wit, M.C.J.

1990-01-01

Apatite fission track ages and confined track length distributions have been determined for rock samples from the south-western continental margin of Africa. The apatite ages fall into two groups, one having early Cretaceous ages and mean confined track lengths of ∼ 14 μm with very few short tracks, and the other having older ages with confined track length distributions containing a significant proportion of strongly annealed tracks (<10 μm). In any particular area the older apatite ages only occur above a critical threshold elevation, forming a regional pattern in the data and indicating cooling of the upper few kilometres of the crust during the early cretaceous. This episode of cooling is shown to have been the consequence of an accelerated phase of erosion associated with the early stages of rifting and break-up of Gondwana, and correlates with sedimentation patterns derived from borehole data for the adjacent offshore basin. (author)

An early cretaceous phase of accelerated erosion on the south-western margin of Africa: evidence from apatite fission track analysis and the offshore sedimentary record

Energy Technology Data Exchange (ETDEWEB)

Brown, R.W.; Gleadow, A.J.W. (La Trobe Univ., Bundoora (Australia)); Rust, D.J.; Summerfield, M.A. (Edinburgh Univ. (UK)); De Wit, M.C.J. (De Beers Consolidated Mines Ltd., Kimberley (South Africa))

1990-01-01

Apatite fission track ages and confined track length distributions have been determined for rock samples from the south-western continental margin of Africa. The apatite ages fall into two groups, one having early Cretaceous ages and mean confined track lengths of {approx} 14 {mu}m with very few short tracks, and the other having older ages with confined track length distributions containing a significant proportion of strongly annealed tracks (<10 {mu}m). In any particular area the older apatite ages only occur above a critical threshold elevation, forming a regional pattern in the data and indicating cooling of the upper few kilometres of the crust during the early cretaceous. This episode of cooling is shown to have been the consequence of an accelerated phase of erosion associated with the early stages of rifting and break-up of Gondwana, and correlates with sedimentation patterns derived from borehole data for the adjacent offshore basin. (author).

Protein-free formation of bone-like apatite: New insights into the key role of carbonation.

Science.gov (United States)

Deymier, Alix C; Nair, Arun K; Depalle, Baptiste; Qin, Zhao; Arcot, Kashyap; Drouet, Christophe; Yoder, Claude H; Buehler, Markus J; Thomopoulos, Stavros; Genin, Guy M; Pasteris, Jill D

2017-05-01

The nanometer-sized plate-like morphology of bone mineral is necessary for proper bone mechanics and physiology. However, mechanisms regulating the morphology of these mineral nanocrystals remain unclear. The dominant hypothesis attributes the size and shape regulation to organic-mineral interactions. Here, we present data supporting the hypothesis that physicochemical effects of carbonate integration within the apatite lattice control the morphology, size, and mechanics of bioapatite mineral crystals. Carbonated apatites synthesized in the absence of organic molecules presented plate-like morphologies and nanoscale crystallite dimensions. Experimentally-determined crystallite size, lattice spacing, solubility and atomic order were modified by carbonate concentration. Molecular dynamics (MD) simulations and density functional theory (DFT) calculations predicted changes in surface energy and elastic moduli with carbonate concentration. Combining these results with a scaling law predicted the experimentally observed scaling of size and energetics with carbonate concentration. The experiments and models describe a clear mechanism by which crystal dimensions are controlled by carbonate substitution. Furthermore, the results demonstrate that carbonate substitution is sufficient to drive the formation of bone-like crystallites. This new understanding points to pathways for biomimetic synthesis of novel, nanostructured biomaterials. Copyright © 2017 Elsevier Ltd. All rights reserved.

A first report of hydroxylated apatite as structural biomineral in Loasaceae - plants’ teeth against herbivores

Science.gov (United States)

Ensikat, Hans-Jürgen; Geisler, Thorsten; Weigend, Maximilian

2016-05-01

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.

Plasma-based water treatment: development of a general mechanistic model to estimate the treatability of different types of contaminants

International Nuclear Information System (INIS)

Mededovic Thagard, Selma; Stratton, Gunnar R; Paek, Eunsu; Dai, Fei; Holsen, Thomas M; Bellona, Christopher L; Bohl, Douglas G; Dickenson, Eric R V

2017-01-01

To determine the types of applications for which plasma-based water treatment (PWT) is best suited, the treatability of 23 environmental contaminants was assessed through treatment in a gas discharge reactor with argon bubbling, termed the enhanced-contact reactor. The contaminants were treated in a mixture to normalize reaction conditions and convective transport limitations. Treatability was compared in terms of the observed removal rate constant ( k obs ). To characterize the influence of interfacial processes on k obs , a model was developed that accurately predicts k obs for each compound, as well as the contributions to k obs from each of the three general degradation mechanisms thought to occur at or near the gas–liquid interface: ‘sub-surface’, ‘surface’ and ‘above-surface’. Sub-surface reactions occur just underneath the gas–liquid interface between the contaminants and dissolved plasma-generated radicals, contributing significantly to the removal of compounds that lack surfactant-like properties and so are not highly concentrated at the interface. Surface reactions occur at the interface between the contaminants and dissolved radicals, contributing significantly to the removal of surfactant-like compounds that have high interfacial concentrations. The contaminants’ interfacial concentrations were calculated using surface-activity parameters determined through surface tension measurements. Above-surface reactions are proposed to take place in the plasma interior between highly energetic plasma species and exposed portions of compounds that extend out of the interface. This mechanism largely accounts for the degradation of surfactant-like contaminants that contain highly hydrophobic perfluorocarbon groups, which are most likely to protrude from the interface. For a few compounds, the degree of exposure to the plasma interior was supported by new and previously reported molecular dynamics simulations results. By reviewing the predicted

Lu-Hf isotope systematics of fossil biogenic apatite and their effects on geochronology

Science.gov (United States)

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

From waste to high-value product: Jackfruit peel derived pectin/apatite bionanocomposites for bone healing applications.

Science.gov (United States)

Govindaraj, Dharman; Rajan, Mariappan; Hatamleh, Ashraf A; Munusamy, Murugan A

2018-01-01

Public requirements encouraged by the current asset framework drive industry to expand its general effectiveness by enhancing existing procedures or finding new uses for waste. Thus, the aim of this study was the isolation, fabrication, and characterization of pectin derived from jackfruit (Artocarpus heterophyllus) peels and the generation of hybrid of pectin (P)/apatite (HA) (P/HA) bionanocomposites. In this process, the natural pectin polymer derived from the peel of jackfruits was used in different concentrations for the fabrication of HA bionanocomposites. Characterization of the isolated pectin and bionanocomposites samples was performed with 1 H NMR and 13 C NMR, FTIR, XRD, SEM-EDX, and HR-TEM. Cytocompatibility, ALP, fibroblast stem cells, anti-inflammatory and cell adhesion testing of the fabricated bionanocomposites was showed good biocompatibility. Our results signify that the fabricated bionanocomposites might be applicable as bone graft materials. Copyright © 2017 Elsevier B.V. All rights reserved.

Preparation of an apatite-based matrix for the confinement of iodine 129; Mise au point d`une matrice apatitique pour le confinement de l`iode 129

Energy Technology Data Exchange (ETDEWEB)

Audubert, F

1995-11-08

The aim of this thesis is the study of the conditioning of iodine 129 from the reprocessing of nuclear wastes. Because of its long half life (1.57 10{sup 7} years), the conditioning of iodine 129 requires a matrix stable during several thousands of years. The study of natural minerals allows the selection of mineral phases having a good long term behaviour. In the first part the policy of nuclear wastes management, and in particular of iodine, is recalled. A naturalistic approach is used to define the best conditioning material and the remarkable properties of apatite in this way are described. In the second part, the preparation and physical-chemical characterization of iodo-apatites are described. A demonstration is made that iodine can penetrate inside vanadate or lead phospho-vanadate apatite-based compounds. The third part deals with the preparation of the conditioning material. The sintering reaction under pressure allows the preparation of composite ceramics including iodo-apatite. A multi-layer coating process is defined: coating of PbI{sub 2} with a Pb{sub 3}(VO{sub 4}){sub 1.6}(PO{sub 4}){sub 0.4} layer and a Ca{sub 10}(PO{sub 4}){sub 6}F{sub 2} layer. Sintering is performed at 700 deg. celsius under a 25 MPa pressure. (J.S.). 131 refs.

Radionuclide Incorporation and Long Term Performance of Apatite Waste Forms

Energy Technology Data Exchange (ETDEWEB)

Wang, Jianwei [Louisiana State Univ., Baton Rouge, LA (United States); Lian, Jie [Rensselaer Polytechnic Inst., Troy, NY (United States); Gao, Fei [Univ. of Michigan, Ann Arbor, MI (United States)

2016-01-04

This project aims to combines state-of-the-art experimental and characterization techniques with atomistic simulations based on density functional theory (DFT) and molecular dynamics (MD) simulations. With an initial focus on long-lived I-129 and other radionuclides such as Cs, Sr in apatite structure, specific research objectives include the atomic scale understanding of: (1) incorporation behavior of the radionuclides and their effects on the crystal chemistry and phase stability; (2) stability and microstructure evolution of designed waste forms under coupled temperature and radiation environments; (3) incorporation and migration energetics of radionuclides and release behaviors as probed by DFT and molecular dynamics (MD) simulations; and (4) chemical durability as measured in dissolution experiments for long term performance evaluation and model validation.

Expanded newborn screening by mass spectrometry: New tests, future perspectives.

Science.gov (United States)

Ombrone, Daniela; Giocaliere, Elisa; Forni, Giulia; Malvagia, Sabrina; la Marca, Giancarlo

2016-01-01

Tandem mass spectrometry (MS/MS) has become a leading technology used in clinical chemistry and has shown to be particularly sensitive and specific when used in newborn screening (NBS) tests. The success of tandem mass spectrometry is due to important advances in hardware, software and clinical applications during the last 25 years. MS/MS permits a very rapid measurement of many metabolites in different biological specimens by using filter paper spots or directly on biological fluids. Its use in NBS give us the chance to identify possible treatable metabolic disorders even when asymptomatic and the benefits gained by this type of screening is now recognized worldwide. Today the use of MS/MS for second-tier tests and confirmatory testing is promising especially in the early detection of new disorders such as some lysosomal storage disorders, ADA and PNP SCIDs, X-adrenoleucodistrophy (X-ALD), Wilson disease, guanidinoacetate methyltransferase deficiency (GAMT), and Duchenne muscular dystrophy. The new challenge for the future will be reducing the false positive rate by using second-tier tests, avoiding false negative results by using new specific biomarkers and introducing new treatable disorders in NBS programs. © 2015 Wiley Periodicals, Inc.

Hydrothermal calcium modification of 316L stainless steel and its apatite forming ability in simulated body fluid.

Science.gov (United States)

Valanezahad, Alireza; Ishikawa, Kunio; Tsuru, Kanji; Maruta, Michito; Matsuya, Shigeki

2011-01-01

To understand the feasibility of calcium (Ca) modification of type 316L stainless steel (316L SS) surface using hydrothermal treatment, 316L SS plates were treated hydrothermally in calcium chloride (CaCl(2)) solution. X-ray photoelectron spectroscopic analysis revealed that the surface of 316L SS plate was modified with Ca after hydrothermal treatment at 200°C. And the immobilized Ca increased with CaCl(2) concentration. However no Ca-modification was occurred for 316L SS plates treated at 100°C. When Ca-modified 316L SS plate was immersed in simulated body fluid (SBF) with ion concentrations nearly equal to those of human blood plasma, low crystalline apatite was precipitated on its surface whereas no precipitate was observed on non Ca-modified 316L SS. The results obtained in the present study indicated that hydrothermal treatment at 200°C in CaCl(2) solution is useful for Ca-modification of 316L SS, and Ca-modification plays important role for apatite precipitation in SBF.

Fluoro-apatite surface composition in aqueous solution deduced from potentiometric, electrokinetic, and solubility measurements, and spectroscopic observations

International Nuclear Information System (INIS)

Chairat, C.; Oelkers, E.H.; Schott, J.; Lartigue, J.E.

2007-01-01

The surface chemistry of fluoro-apatite in aqueous solution was investigated using electrokinetic techniques, potentiometric titrations, solubility measurements, and attenuated total reflection infrared spectroscopy. All methods indicate the formation of Ca/F depleted, P enriched altered layer via exchange reactions between H + and Ca 2+ , and OH - and F - at the fluoro-apatite (FAP) surface. Observations suggest that this leached layer has a di-calcium phosphate (CaHPO 4 ) composition and that it controls the apparent solubility of FAP. Electrokinetic measurements yield an iso-electric point value of 1 ± 0.5 consistent with a negatively charged FAP surface at pH ≥ 1. In contrast, surface titrations give an apparent pH of point of zero charge of similar to 7.7, consistent with a positively charged surface at pH ≤ 7.7. These differences are shown to stem from proton consumption by both proton exchange and dissolution reactions at the FAP surface. After taking account for these effects, FAP surface charge is shown to be negative to at least pH 4 by surface titration analysis. (authors)

Fission track ages on apatite of Bergell rocks from central Alps and Bergell boulders in Oligocene sediments

International Nuclear Information System (INIS)

Wagner, G.A.; Miller, D.S.

1979-01-01

Previous radiometric dating studies indicated that the Bergell region, in contrast to other regions of the Central Alps, experienced an early, rapid uplift, but with decreasing rate. Furthermore, there is also a geological record of the early uplift history of the Bergell granite by the existence of boulders which were derived from this granite and which occur in the Late Oligocene sediments of the Po plain. In this work the uplift history of the Bergell is studied in more detail by fission track dating of additional apatites from the Bergell region. Secondly, by determining apatite fission track ages the granitic boulders of the Po plain can be re-assigned to their original vertical position within the Bergell intrusive before erosion removed them in Late Oligocene time. A rather conservative estimate replaces them 6 km above the present morphology of the Bergell massif. Thus, the thickness of the Bergell granite must have been at least 8 km. Generally, fission track studies on boulders may become an important tool to study the vertical extent of mountain chains during the geological past. (Auth.)

Nanodimensional and Nanocrystalline Apatites and Other Calcium Orthophosphates in Biomedical Engineering, Biology and Medicine

Directory of Open Access Journals (Sweden)

Sergey V. Dorozhkin

2009-11-01

Full Text Available Recent developments in biomineralization have already demonstrated that nanosized particles play an important role in the formation of hard tissues of animals. Namely, the basic inorganic building blocks of bones and teeth of mammals are nanodimensional and nanocrystalline calcium orthophosphates (in the form of apatites of a biological origin. In mammals, tens to hundreds nanocrystals of a biological apatite were found to be combined into self-assembled structures under the control of various bioorganic matrixes. In addition, the structures of both dental enamel and bones could be mimicked by an oriented aggregation of nanosized calcium orthophosphates, determined by the biomolecules. The application and prospective use of nanodimensional and nanocrystalline calcium orthophosphates for a clinical repair of damaged bones and teeth are also known. For example, a greater viability and a better proliferation of various types of cells were detected on smaller crystals of calcium orthophosphates. Thus, the nanodimensional and nanocrystalline forms of calcium orthophosphates have a great potential to revolutionize the field of hard tissue engineering starting from bone repair and augmentation to the controlled drug delivery devices. This paper reviews current state of knowledge and recent developments of this subject starting from the synthesis and characterization to biomedical and clinical applications. More to the point, this review provides possible directions of future research and development.

Phase 1 report on the Bear Creek Valley treatability study, Oak Ridge Y-12 Plant, Oak Ridge, Tennessee

International Nuclear Information System (INIS)

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

Phase 1 report on the Bear Creek Valley treatability study, Oak Ridge Y-12 Plant, Oak Ridge, Tennessee

Energy Technology Data Exchange (ETDEWEB)

NONE

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.

Biomimetically grown apatite spheres from aggregated bioglass nanoparticles with ultrahigh porosity and surface area imply potential drug delivery and cell engineering applications.

Science.gov (United States)

El-Fiqi, Ahmed; Buitrago, Jennifer O; Yang, Sung Hee; Kim, Hae-Won

2017-09-15

Here we communicate the generation of biomimetically grown apatite spheres from aggregated bioglass nanoparticles and the potential properties applicable for drug delivery and cell/tissue engineering. Ion releasing nanoparticulates of bioglass (85%SiO 2 -15%CaO) in a mineralizing medium show an intriguing dynamic phenomenon - aggregation, mineralization to apatite, integration and growth into micron-sized (1.5-3μm) spheres. During the progressive ionic dissolution/precipitation reactions, nano-to-micro-morphology, glass-to-crystal composition, and the physico-chemical properties (porosity, surface area, and charge) change dynamically. With increasing reaction period, the apatite becomes more crystallized with increased crystallinity and crystal size, and gets a composition closer to the stoichiometry. The developed microspheres exhibit hierarchical surface nanostructure, negative charge (ς-potential of -20mV), and ultrahigh mesoporosity (mesopore size of 6.1nm, and the resultant surface area of 63.7m 2 /g and pore volume of 0.153cm 3 /g) at 14days of mineralization, which are even higher than those of its precursor bioglass nanoparticles. Thanks to these properties, the biomimetic mineral microspheres take up biological molecules effectively, i.e., loading capacity of positive-charged protein is over 10%. Of note, the release is highly sustainable at a constant rate, i.e., profiling almost 'zero-order' kinetics for 4weeks, suggesting the potential usefulness as protein delivery systems. The biomimetic mineral microspheres hold some remnant Si in the core region, and release calcium, phosphate, and silicate ions over the test period, implying the long-term ionic-related therapeutic functions. The mesenchymal stem cells favour the biomimetic spheres with an excellent viability. Due to the merit of sizes (a few micrometers), the spheres can be intercalated into cells, mediating cellular interactions in 3D cell-spheroid engineering, and also can stimulate osteogenic

Mesozoic-Cenozoic tectonic evolution and its relation to sandstone-type uranium mineralization in northern Tarim area--Evidence from apatite fission track

International Nuclear Information System (INIS)

Liu Hongxu; Dong Wenming; Liu Zhangyue; Chen Xiaolin

2009-01-01

The apatite fission track dating and inversion result of geological thermal history of four rock specimens from Sawafuqi area and Talike area in northern Tarim Basin show that two areas uplifted at different ages. The apatite fission track ages of Sawafuqi range from 3.5 to 3.9 Ma, while the ages of Talike range from 53 to 59 Ma. The thermal history recorded by rock samples reveals that there are at least three prominent cooling phases since Late Cretaceous epoch. Detailed study was made on the division of uplifting stages during Mesozoic and Cenozoic tectonic evolution with the existing data in northern Tarim area. And new ideas on tectonic evolution and sandstone-type uranium mineralization have been put forward by combining with the sandstone-type uranium mineralization ages in this area.(authors)

Plasma-based water treatment: development of a general mechanistic model to estimate the treatability of different types of contaminants

Science.gov (United States)

Mededovic Thagard, Selma; Stratton, Gunnar R.; Dai, Fei; Bellona, Christopher L.; Holsen, Thomas M.; Bohl, Douglas G.; Paek, Eunsu; Dickenson, Eric R. V.

2017-01-01

To determine the types of applications for which plasma-based water treatment (PWT) is best suited, the treatability of 23 environmental contaminants was assessed through treatment in a gas discharge reactor with argon bubbling, termed the enhanced-contact reactor. The contaminants were treated in a mixture to normalize reaction conditions and convective transport limitations. Treatability was compared in terms of the observed removal rate constant (k obs). To characterize the influence of interfacial processes on k obs, a model was developed that accurately predicts k obs for each compound, as well as the contributions to k obs from each of the three general degradation mechanisms thought to occur at or near the gas-liquid interface: ‘sub-surface’, ‘surface’ and ‘above-surface’. Sub-surface reactions occur just underneath the gas-liquid interface between the contaminants and dissolved plasma-generated radicals, contributing significantly to the removal of compounds that lack surfactant-like properties and so are not highly concentrated at the interface. Surface reactions occur at the interface between the contaminants and dissolved radicals, contributing significantly to the removal of surfactant-like compounds that have high interfacial concentrations. The contaminants’ interfacial concentrations were calculated using surface-activity parameters determined through surface tension measurements. Above-surface reactions are proposed to take place in the plasma interior between highly energetic plasma species and exposed portions of compounds that extend out of the interface. This mechanism largely accounts for the degradation of surfactant-like contaminants that contain highly hydrophobic perfluorocarbon groups, which are most likely to protrude from the interface. For a few compounds, the degree of exposure to the plasma interior was supported by new and previously reported molecular dynamics simulations results. By reviewing the predicted

Lanthanum germanate-based apatites as electrolyte for SOFCs

Energy Technology Data Exchange (ETDEWEB)

Marrero-Lopez, D.; Diaz-Carrasco, P.; Ramos-Barrado, J.R. [Departamento de Fisica Aplicada I, Laboratorio de Materiales y Superficies (Unidad Asociada al C.S.I.C.), Universidad de Malaga, 29071 Malaga (Spain); Pena-Martinez, J. [Instituto de Energias Renovables, Parque Tecnologico, Universidad de Castilla La Mancha, 02006 Albacete (Spain); Ruiz-Morales, J.C. [Departamento de Quimica Inorganica, Universidad de La Laguna, 38200 La Laguna, Tenerife (Spain)

2011-02-15

Germanate apatites with composition La{sub 10-x}Ge{sub 5.5}Al{sub 0.5}O{sub 26.75-3x/2} have been evaluated for the first time as possible electrolytes for solid oxide fuel cells (SOFCs). Different electrode materials have been considered in this study, i.e. manganite, ferrite, nickelates and cobaltite as cathode materials; and NiO-CGO composite and chromium-manganite as anodes. The chemical compatibility and electrochemical performance of these electrodes with La{sub 9.8}Ge{sub 5.5}Al{sub 0.5}O{sub 26.45} have been studied by X-ray powder diffraction (XRPD) and impedance spectroscopy. The XRPD analysis did not reveal appreciable bulk reactivity with the formation of reaction products between the germanate electrolyte and these electrodes up to 1,200 C. However, a significant cation interdiffusion was observed by energy dispersive spectroscopy (EDS) at the electrode/electrolyte interface, which leads to a significant decrease of the performance of these electrodes. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Monomer conversion, dimensional stability, strength, modulus, surface apatite precipitation and wear of novel, reactive calcium phosphate and polylysine-containing dental composites.

Directory of Open Access Journals (Sweden)

Kanokrat Kangwankai

Full Text Available The aim was to assess monomer conversion, dimensional stability, flexural strength / modulus, surface apatite precipitation and wear of mono / tri calcium phosphate (CaP and polylysine (PLS-containing dental composites. These were formulated using a new, high molecular weight, fluid monomer phase that requires no polymerisation activator.Urethane and Polypropylene Glycol Dimethacrylates were combined with low levels of an adhesion promoting monomer and a light activated initiator. This liquid was mixed with a hybrid glass containing either 10 wt% CaP and 1 wt% PLS (F1 or 20 wt% CaP and 2 wt% PLS (F2. Powder to liquid mass ratio was 5:1. Commercial controls included Gradia Direct Posterior (GD and Filtek Z250 (FZ. Monomer conversion and polymerisation shrinkage were calculated using Fourier Transform Infrared (FTIR. Subsequent volume increases in water over 7 weeks were determined using gravimetric studies. Biaxial flexural strength (BFS / modulus (BFM reduction and surface apatite precipitation upon 1 and 4 weeks immersion in water versus simulated body fluid (SBF were assessed using a mechanical testing frame and scanning electron microscope (SEM. Mass / volume loss and surface roughness (Ra following 7 weeks water immersion and subsequent accelerated tooth-brush abrasion were examined using gravimetric studies and profilometer.F1 and F2 exhibited much higher monomer conversion (72% than FZ (54% and low calculated polymerization shrinkage (2.2 vol%. Final hygroscopic expansions decreased in the order; F2 (3.5 vol% > F1 (1.8 vol% ~ Z250 (1.6 vol% > Gradia (1.0 vol%. BFS and BFM were unaffected by storage medium type. Average BFS / BFM upon 4 weeks immersion reduced from 144 MPa / 8 GPa to 107 MPa / 5 GPa for F1 and 105 MPa / 6 GPa to 82 MPa / 4 GPa for F2. Much of this change was observed in the first week of immersion when water sorption rate was high. Surface apatite layers were incomplete at 1 week, but around 2 and 15 micron thick for F1 and

On-line sampling of apatite-nepheline ore using apron feeders by gamma-gamma method

Energy Technology Data Exchange (ETDEWEB)

Bliznyuk, G.I.

1981-01-01

The yield flow of an underground mine equipped with a crushing complex was investigated. /sup 241/Am source and 20x20 mm NaI(Tl) crystal were used; the lump size of apatite-nepheline ore was 200 mm, P/sub 2/O/sub 5/ content varied from 10 to 22%. The mean-square error was 1% P/sub 2/O/sub 5/ in 100-ton portions of mined ore. The method can be also applied for sampling iron, copper-nickel, and polymetallic ores.

Reconstructing Post-Carboniferous History of the Krkonoše Piedmont Basin Using Detrital Apatite Fission-Track Data

Czech Academy of Sciences Publication Activity Database

Martínek, K.; Svojtka, Martin; Filip, Jiří

2006-01-01

Roč. 20, - (2006), s. 91-92 ISSN 1210-9606. [Meeting of the Central European Tectonic Studies Group /4./. Zakopane, 19.04.2006-22.04.2006] Institutional research plan: CEZ:AV0Z30130516 Keywords : fission-track * Krkonoše * apatite Subject RIV: DB - Geology ; Mineralogy http://geolines.gli.cas.cz/fileadmin/volumes/volume20/G20-091b.pdf

Surface-Modification of Carbonate Apatite Nanoparticles Enhances Delivery and Cytotoxicity of Gemcitabine and Anastrozole in Breast Cancer Cells

Directory of Open Access Journals (Sweden)

Fitya Syarifa Mozar

2017-06-01

Full Text Available pH sensitive nanoparticles of carbonate apatite (CA have been proven to be effective delivery vehicles for DNA, siRNAs and proteins. More recently, conventional anti-cancer drugs, such as doxorubicin, methotrexate and cyclophosphamide have been successfully incorporated into CA for intracellular delivery to breast cancer cells. However, physical and chemical properties of drug molecules appeared to affect their interactions with CA, with hydrophillic drug so far exhibiting better binding affinity and cellular uptakes compared to hydrophobic drugs. In this study, anastrozole, a non-steroidal aromatase inhibitor which is largely hydrophobic, and gemcitabine, a hydrophilic nucleoside inhibitor were used as solubility models of chemotherapy drug. Aggregation tendency of poorly soluble drugs resulting in larger particle-drug complex size might be the main factor hindering their delivery effectiveness. For the first time, surface modification of CA with poly(ethylene glycol (PEG has shown promising result to drastically reduce anastrozole- loaded CA particle size, from approximately 1000 to 500 nm based on zeta sizer analysis. Besides PEG, a cell specific ligand, in this case fibronectin, was attached to the particles in order to facilitate receptor mediated endocytosis based on fibronectin–integrin interaction. High-performance liquid chromatography (HPLC was performed to measure uptake of the drugs by breast cancer cells, revealing that surface modification increased the drug uptake, especially for the hydrophobic drug, compared to the uncoated particles and the free drug. In vitro chemosensitivity assay and in vivo tumor regression study also showed that coated apatite/drug nanoparticle complexes presented higher cytotoxicity and tumor regression effects than uncoated apatite/drug nanoparticles and free drugs, indicating that surface modification successfully created optimum particles size with the consequence of more effective uptake along with

Probing the limit of magnesium uptake by β-tricalcium phosphate in biphasic mixtures formed from calcium deficient apatites

Energy Technology Data Exchange (ETDEWEB)

Kumar, P. Nandha; Mishra, Sandeep K.; Kannan, S., E-mail: para_kanna@yahoo.com

2015-11-15

A series of magnesium doped non-stoichiometric calcium deficient apatites were synthesized through an aqueous precipitation route. The resultant structural changes during heat treatment were investigated by X-ray diffraction, Raman and FT-IR spectroscopy and Rietveld refinement. The results confirmed the formation of biphasic mixtures comprising Ca{sub 10}(PO{sub 4}){sub 6}(OH){sub 2} and β-Ca{sub 3}(PO{sub 4}){sub 2} after heat treatment at 1000 °C with the preferential occupancy of Mg{sup 2+} at the crystal lattice of β-Ca{sub 3}(PO{sub 4}){sub 2}. The concentration of Mg{sup 2+} uptake in β-Ca{sub 3}(PO{sub 4}){sub 2} is limited till reaching the stoichiometric ratio of (Ca+Mg)/P=1.67 and beyond this stoichiometric value [(Ca+Mg)/P>1.67], Mg{sup 2+} precipitates as Mg(OH){sub 2} and thereafter gets converted to MgO during heat treatment. Any kind of Mg{sup 2+} uptake in the crystal lattice of Ca{sub 10}(PO{sub 4}){sub 6}(OH){sub 2} is discarded from the investigation. - Highlights: • Aqueous co-precipitation of calcium deficient apatites with excess magnesium (Mg{sup 2+}) additions. • Heat treatments beyond 800 °C results in the formation of biphasic apatite mixtures. • Mg{sup 2+} gets accommodated at the β-Ca{sub 3}(PO{sub 4}){sub 2} lattice of biphasic mixtures. • Mg{sup 2+} additions exceeding stoichiometric value (Ca/P>1.67) results in its formation as MgO. • Mg{sup 2+} occupancy at β-Ca{sub 3}(PO{sub 4}){sub 2} lattice delays its allotropic conversion α-Ca{sub 3}(PO{sub 4}){sub 2} till 1350 °C.

A hardenability test proposal

Energy Technology Data Exchange (ETDEWEB)

Murthy, N.V.S.N. [Ingersoll-Rand (I) Ltd., Bangalore (India)

1996-12-31

A new approach for hardenability evaluation and its application to heat treatable steels will be discussed. This will include an overview and deficiencies of the current methods and discussion on the necessity for a new approach. Hardenability terminology will be expanded to avoid ambiguity and over-simplification as encountered with the current system. A new hardenability definition is proposed. Hardenability specification methods are simplified and rationalized. The new hardenability evaluation system proposed here utilizes a test specimen with varying diameter as an alternative to the cylindrical Jominy hardenability test specimen and is readily applicable to the evaluation of a wide variety of steels with different cross-section sizes.

Reconciling Conflicting Geologic and Thermochronologic Interpretations Via Multiple Apatite Thermochronometers (AHe, AFT, and 4He/3He): 6 Ma Incision of the Westernmost Grand Canyon

Science.gov (United States)

Winn, C.; Karlstrom, K. E.; Shuster, D. L.; Kelley, S.; Fox, M.

2017-12-01

The application of low-temperature apatite thermochronology to the incision history of the Grand Canyon has led to conflicting hypotheses of either a 70 Ma ("old") or conflict with these lines of evidence and indicate a much older ( 70 Ma) westernmost Grand Canyon. We reconcile this conflict by applying apatite (U-Th)/He ages (AHe), 4He/3He thermochronometry, and apatite fission track ages and lengths (AFT) to the same sample at a key location. Using HeFTy, t-T paths that predict these data show cooling from ˜100 °C to 40-60 °C at 70-50 Ma, long-term residence at 40-60 °C from 50-10 Ma, and cooling to surface temperatures after 10 Ma, indicating young incision. New AFT (5) and AHe (3) datasets are also presented here. When datasets are examined separately, AHe data show t-T paths that cool to surface temperatures during the Laramide, consistent with an "old" Canyon. When multiple methods are applied, t-T paths instead show young incision. This inconsistency demonstrates the age of the Grand Canyon controversy. Here we reconcile the difference in t-T paths by adjusting model parameters to account for uncertainty in the rate of radiation damage annealing in apatite during burial heating and the resulting variations in He retentivity. In this area, peak burial conditions during the Laramide were likely insufficient to fully anneal radiation damage that accumulated during prolonged near-surface residence prior to burial. We conclude that application of multiple thermochronometers from common rocks reconciles conflicting thermochronologic interpretations and these data are best explained by a "young" westernmost Grand Canyon.

Apatite fission track analysis for revealing tectonic events of the Bayinguole area in the west section of Eastern Kunlun Mountains, northern Qinghai-Tibet Plateau

International Nuclear Information System (INIS)

Chen Xiaoning; Yuan Wanming; Hao Nana; Duan Hongwei; Feng Yunlei; Zhang Aikui

2014-01-01

Background: Qimantage is an important tectonic metallogenic belt in western part of East Kunlun Mountain. It has experienced complex geological evolution, and significant mineralization. However, because of the plateau climate and inaccessibility, fewer research works have been done on this area, especially after Indo-sinian epoch. Purpose: Our work is to research tectonic activity, thermal history and uplifting around Bayinguole river in Qimantage belt. Methods: The apatite fission-track method was applied to research the tectonic setting, simulate the thermal history and calculate the uplift size and uplift speed. Results: A series of apatite fission track ages from granitoid samples in Bayinguole area of Eastern Kunlun Mountain were obtained, ranging from 120 Ma to 47 Ma that might be divided into three groups': 120-100 Ma, 67 Ma and 54-47 Ma. These ages reflected tectonic events in this area very well. Conclusions: The 120-100 Ma and 67 Ma ages present collision-convergences of Gangdese terrane and Himalayan terrane with their north-side terranes in Early Cretaceous and Late Cretaceous respectively. The ages of 54-47 Ma reflect post-orogenic stretching events in Eocene. Three stages of thermal evolution history are revealed by apatite fission track modeling in this area. Stage one 180-140 Ma is in the bottom temperature of apatite fission track anneal zone. Stage two 140-13 Ma records slow cooling. The last stage after 13 Ma records rapid cooling with temperature dropped 50℃. The uplifting ranges for these three stages are 1.0 km, 0.6 km and 1.4 km, respectively. The cumulative amount of uplift is about 3.0 km. The formula calculations for the 3 samples have their rock uplifts of 3623 m, 3317 m and 3769 m, respectively, averaging 3570 m, in accordance with the results based on the 3 stage thermal history. (authors)

Feasibility/treatability studies for removal of heavy metals from training range soils at the Grafenwoehr Training Area, Germany

Energy Technology Data Exchange (ETDEWEB)

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.

Manufacture of nanosized apatite coatings on titanium with different surface treatments using a supersaturated calcification solution

Directory of Open Access Journals (Sweden)

Adrian Paz Ramos

Full Text Available The biomimetic method is used for the deposition of calcium phosphate coatings (Ca - P on the surface of different biomaterials. However, the application of this method requires long exposure times in order to obtain a suitable layer thickness for its use in medical devices. In this paper, we present a fast approach to obtain apatite coatings on titanium, using a combination of supersaturated calcification solution (SCS with chemical modification of the titanium surface. Also, it was evaluated the effect of four different surface treatments on the apatite deposition rate. Commercially pure titanium plates were activated by chemical or thermochemical treatments. Then, the activated samples were immersed in a solution with high content of calcium and phosphate ions at 37 ºC for 24 h, mimicking the physiological conditions. The coatings were studied by Fourier transform infrared spectroscopy (FTIR, X-ray diffraction (XRD, scanning electron microscopy (SEM and energy dispersive X-ray spectroscopy (EDX. The use of SCS solutions allowed the formation of crystalline hydroxyapatite coatings within a period of 24 h with a thickness between 1 and 5.3 µm. Besides, precipitates of hydroxyapatite nanoparticles with a globular configuration, forming aggregates with submicrometer size, were found in SCS solutions.

Apatite layer growth on glassy Zr{sub 48}Cu{sub 36}Al{sub 8}Ag{sub 8} sputtered titanium for potential biomedical applications

Energy Technology Data Exchange (ETDEWEB)

Thanka Rajan, S.; Karthika, M. [Electrochemical Materials Science Division, CSIR-Central Electrochemical Research Institute, Karaikudi 630003 (India); Bendavid, Avi [Plasma Processing & Deposition Team, CSIRO Manufacturing Flagship, LindField, 2070, Sydney (Australia); Subramanian, B., E-mail: subramanianb3@gmail.com [Plasma Processing & Deposition Team, CSIRO Manufacturing Flagship, LindField, 2070, Sydney (Australia); Electrochemical Materials Science Division, CSIR-Central Electrochemical Research Institute, Karaikudi 630003 (India)

2016-04-30

Graphical abstract: - Highlights: • Metallic biomaterials are surface modified by Zr based TFMGs. • A bone-like apatite layer was grown on a Ni-free Zr-based TFMG in vitro. • Apatite layer growth confirmed by XRD and XPS analysis indicates its bioactivity. • Electrochemical response of the TFMGs in SBF possesses good corrosion resistance. - Abstract: The bioactivity of magnetron sputtered thin film metallic glasses (TFMGs) of Zr{sub 48}Cu{sub 36}Al{sub 8}Ag{sub 8} (at.%) on titanium substrates was tested for bio implant applications. The structural and elemental compositions of TFMGs were analyzed by XRD, XPS and EDAX. X-ray diffraction analysis displayed a broad hump around the incident angle of 30–50°, suggesting that the coatings possess a glassy structure. An in situ crystal growth of hydroxyapatite was observed by soaking the sputtered specimen in simulated body fluid (SBF). The nucleation and growth of a calcium phosphate (Ca–P) bone-like hydroxyapatite on Zr{sub 48}Cu{sub 36}Al{sub 8}Ag{sub 8} (at.%) TFMG from SBF was investigated by using XRD, AFM and SEM. The presence of calcium and phosphorus elements was confirmed by EDAX and XPS. In vitro electrochemical corrosion studies indicated that the Zr-based TFMG coating sustain in the stimulated body-fluid (SBF), exhibiting superior corrosion resistance with a lower corrosion penetration rate and electrochemical stability than the bare crystalline titanium substrate.

Treatability studies

DEFF Research Database (Denmark)

Bennedsen, Lars Rønn; Studds, Phil

developed a mobile test unit including equipment for both standard and more advanced oxidation test directly on the site. The remediation techniques included are electrochemical oxidation, photochemical/photocatalytic oxidation, ozone, Fenton’s, permanganate, and persulfate among others. A versatile...

Vacuum-sintered body of a novel apatite for artificial bone

Science.gov (United States)

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

The effect of serum proteins on apatite growth for 45S5 Bioglass and common sol-gel derived glass in SBF

Directory of Open Access Journals (Sweden)

Lin Sen

2018-02-01

Full Text Available The inhibitive effects of serum proteins on apatite growth was compared between melt-derived 45S5 Bioglass® and sol-gel derived bioactive glass of the 70S30C (70 mol% SiO2, 30 mol% CaO. By using techniques of XRD, TEM and Raman spectroscopy, the transformation of amorphous calcium phosphate to crystalline apatite, and the resulting size and aspect ratio of the crystals, in simulated body fluid (SBF, was seen to decrease in the presence of serum. XRD showed more rapid HA formation on Bioglass particles, compared to that forming on 70S30C particles, however TEM showed similar size and frequency of the needle-like crystals. Phosphate reduction in SBF was similar for Bioglass and 70S30C. Calcium carbonate formation was more likely on the phosphate-free sol-gel glass than on Bioglass.

Comparison of two bond strength testing methodologies for bilayered all-ceramics

NARCIS (Netherlands)

Dundar, Mine; Ozcan, Mutlu; Gokce, Bulent; Comlekoglu, Erhan; Leite, Fabiola; Valandro, Luiz Felipe

Objectives. This study compared the shear bond strength (SBS) and microtensile (MTBS) testing methodologies for core and veneering ceramics in four types of all-ceramic systems. Methods. Four different ceramic veneer/core combinations, three of which were feldspathic and the other a fluor-apatite to

LA-ICP-MS U-Pb apatite dating of Lower Cretaceous rocks from teschenite-picrite association in the Silesian Unit (southern Poland

Directory of Open Access Journals (Sweden)

Szopa Krzysztof

2014-08-01

Full Text Available The main products of volcanic activity in the teschenite-picrite association (TPA are shallow, sub-volcanic intrusions, which predominate over extrusive volcanic rocks. They comprise a wide range of intrusive rocks which fall into two main groups: alkaline (teschenite, picrite, syenite, lamprophyre and subalkaline (dolerite. Previous 40Ar/39Ar and 40K/40Ar dating of these rocks in the Polish Outer Western Carpathians, performed on kaersutite, sub-silicic diopside, phlogopite/biotite as well as on whole rock samples has yielded Early Cretaceous ages. Fluorapatite crystals were dated by the U-Pb LA-ICP-MS method to obtain the age of selected magmatic rocks (teschenite, lamprophyre from the Cieszyn igneous province. Apatite-bearing samples from Boguszowice, Puńców and Lipowa yield U-Pb ages of 103± 20 Ma, 119.6 ± 3.2 Ma and 126.5 ± 8.8 Ma, respectively. The weighted average age for all three samples is 117.8 ± 7.3 Ma (MSWD = 2.7. The considerably smaller dispersion in the apatite ages compared to the published amphibole and biotite ages is probably caused by the U-Pb system in apatite being less susceptible to the effects of hydrothermal alternation than the 40Ar/39Ar or 40K/40Ar system in amphibole and/or biotite. Available data suggest that volcanic activity in the Silesian Basin took place from 128 to 103 Ma with the the main magmatic phase constrained to 128-120 Ma.

Multiple cooling episodes in the Central Tarim (Northwest China) revealed by apatite fission track analysis and vitrinite reflectance data

Science.gov (United States)

Chang, Jian; Qiu, Nansheng; Song, Xinying; Li, Huili

2016-06-01

Apatite fission track and vitrinite reflectance are integrated for the first time to study the cooling history in the Central Tarim, northwest China. The paleo-temperature profiles from vitrinite reflectance data of the Z1 and Z11 wells showed a linear relationship with depth, suggesting an approximately 24.8 °C/km paleo-geothermal gradient and 2700-3900 m of erosion during the Early Mesozoic. The measured apatite fission track ages from well Z2 in the Central Tarim range from 39 to 159 Ma and effectively record the Meso-Cenozoic cooling events that occurred in Central Tarim. Moreover, two cooling events at 190-140 Ma in the Early Jurassic-Early Cretaceous and 80-45 Ma in the Late Cretaceous-Paleocene revealed by measured AFT data and thermal modeling results are related to the collisions of the Qiangtang-Lhasa terranes and the Greater India Plate with the southern margin of the Eurasian Plate, respectively. This study provides new insights into the tectonic evolution of the Tarim Basin (and more broadly Central Asia) and for hydrocarbon generation and exploration in the Central Tarim.

Characterization and potential application of pataua vegetable oil in apatite flotation; Caracterizacao e potencial aplicacao do oleo vegetal de pataua na floracao de apatita

Energy Technology Data Exchange (ETDEWEB)

Oliveira, P.S. de; Mansur, H.S.; Peres, A.E.C., E-mail: eng.priscila.oliveira@gmail.com [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil)

2016-07-01

The present research characterizes the Pataua palm (Oenocarpus bataua) oil regarding to its fatty acids profile and acidity index, and evaluates its use for apatite flotation. The Pataua oil evaluated is unsaturated e predominantly composed of cis-9-octadecenoic acid (oleic acid). The mineral sample characterization revealed a material composed by a fluoroapatite deficient in fluorine, a possibly result of isomorphic substitution, and with quartz and monazite inclusions. The analysis of the mineral after reagent conditioning, by Fourier Transform Infrared Spectroscopy (FTIR), pointed to the presence of characteristic bands of carbon chains and carboxylate group, suggesting the collector adsorption through the mechanisms of chemisorption and insoluble calcium salts precipitation. Thus, it is proposed the Pataua oil potential use in flotation systems aiming apatite recovery. (author)

Bioremediation of petroleum hydrocarbons in soil: Activated sludge treatability study

International Nuclear Information System (INIS)

Rue-Van Es, J.E. La.

1993-05-01

Batch activated sludge treatability studies utilizing petroleum hydrocarbon contaminated soils (diesel oil and leaded gasoline) were conducted to determine: initial indigenous biological activity in hydrocarbon-contaminated soils; limiting factors of microbiological growth by investigating nutrient addition, chemical emulsifiers, and co-substrate; acclimation of indigenous population of microorganisms to utilize hydrocarbons as sole carbon source; and temperature effects. Soil samples were taken from three different contaminated sites and sequencing batch reactors were run. Substrate (diesel fuel) and nutrient were added as determined by laboratory analysis of orthophosphate, ammonia nitrogen, chemical oxygen demand, and total organic carbon. Substrate was made available to the bacterial mass by experimenting with four different chemical emulsifiers. Indigenous microorganisms capable of biotransforming hydrocarbons seem to be present in all the contaminated soil samples received from all sites. Microscopic analysis revealed no visible activity at the beginning of the study and presence of flagellated protozoa, paramecium, rotifers, and nematodes at the end of the year. Nutrient requirements and the limiting factors in microorganism growth were determined for each site. An emulsifier was initially necessary to make the substrate available to the microbial population. Decreases in removal were found with lowered temperature. Removal efficiencies ranged from 50-90%. 95 refs., 11 figs., 13 tabs

Bioremediation of petroleum hydrocarbons in soil: Activated sludge treatability study

Energy Technology Data Exchange (ETDEWEB)

Rue-Van Es, J.E. La.

1993-05-01

Batch activated sludge treatability studies utilizing petroleum hydrocarbon contaminated soils (diesel oil and leaded gasoline) were conducted to determine: initial indigenous biological activity in hydrocarbon-contaminated soils; limiting factors of microbiological growth by investigating nutrient addition, chemical emulsifiers, and co-substrate; acclimation of indigenous population of microorganisms to utilize hydrocarbons as sole carbon source; and temperature effects. Soil samples were taken from three different contaminated sites and sequencing batch reactors were run. Substrate (diesel fuel) and nutrient were added as determined by laboratory analysis of orthophosphate, ammonia nitrogen, chemical oxygen demand, and total organic carbon. Substrate was made available to the bacterial mass by experimenting with four different chemical emulsifiers. Indigenous microorganisms capable of biotransforming hydrocarbons seem to be present in all the contaminated soil samples received from all sites. Microscopic analysis revealed no visible activity at the beginning of the study and presence of flagellated protozoa, paramecium, rotifers, and nematodes at the end of the year. Nutrient requirements and the limiting factors in microorganism growth were determined for each site. An emulsifier was initially necessary to make the substrate available to the microbial population. Decreases in removal were found with lowered temperature. Removal efficiencies ranged from 50-90%. 95 refs., 11 figs., 13 tabs.

Extraction and characterisation of apatite- and tricalcium phosphate-based materials from cod fish bones

International Nuclear Information System (INIS)

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 (Ca 10 (PO 4 ) 6 (OH) 2 and β-Ca(PO 4 ) 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 (Ca 10 (PO 4 ) 6 Cl 2 ) and fluorapatite (Ca 10 (PO 4 ) 6 F 2 ) were obtained using CaCl 2 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. - Highlights: ► Apatite and calcium phosphate compounds extraction from cod fish bones ► Bone calcination: biphasic material hydroxyapatite-calcium phosphate production ► Bone pre-treatments in solution change the material composition. ► Single phase materials (hydroxy-, chloro- or fluoroapatite) are obtained. ► Concentration of other elements (Na, F, Cl) suitable for biomedical applications

Study of retention properties of fluoro-apatite carbonate relative to Ni(II), Am(III) and Th(IV); Etude des proprietes de retention des carbonate fluoroapatites vis-a-vis de Ni(II), Am(III) et Th(IV)

Energy Technology Data Exchange (ETDEWEB)

Perrone, Jane [Inst. de Physique Nucleaire, Paris-11 Univ., 91 - Orsay (France)

1999-07-12

Apatite minerals and particularly the carbonated species (francolites), are characterized by their chemical and geological stability and also by their capacity to retain durably a large number of elements. Therefore, they should be able to improve the retention properties of the engineered barriers of a deep geological nuclear waste repository. But there is a wide variety of francolites, so we focused our study on a synthetic carbonate fluoro-apatite of formula: Ca{sub 10}(PO{sub 4}){sub 5}(CO{sub 3})(F,OH){sub 3} and on a natural apatite. We first studied their solubility which is an important criterion for the choice of the materials. A particular attention was also paid to the determination of their surface characteristics and to the study of the radionuclide/solution interactions. Sorption experiments have been performed for the three radionuclides and the influence of various parameters has been investigated. The modelling of the sorption isotherms with surface complexation models leads us to estimate the values of the constants associated to the equilibria under consideration. We have also demonstrated that the phosphate ions of the solution participate to the immobilization of americium as the AmPO{sub 4},xH{sub 2}O compound. Both apatites show high retention levels for the actinides: the sorption is quite total over all the pH range studied and the Kd values are close to 10{sup 4} m{sup 3} kg{sup -1}. Consequently, the use of apatites could be considered as a specific solution for the immobilisation of heavy elements, specially actinides. Moreover, the results indicate that high amounts of carbonates and impurities do not alter the retention properties of francolites. This bears out the feasibility of the use of natural apatites as additives for the engineered barrier materials. (author)

Photoluminescence in the characterization and early detection of biomimetic bone-like apatite formation on the surface of alkaline-treated titanium implant: state of the art.

Science.gov (United States)

Sepahvandi, Azadeh; Moztarzadeh, Fathollah; Mozafari, Masoud; Ghaffari, Maryam; Raee, Nahid

2011-09-01

Photoluminescence (PL) property is particularly important in the characterization of materials that contain significant proportions of noncrystalline components, multiple phases, or low concentrations of mineral phases. In this research, the ability of biomimetic bone-like apatite deposition on the surface of titanium alloy (Ti6Al4V) substrates in simulated body fluid (SBF) right after alkaline-treatment and subsequent heat-treatment was studied by the inherent luminescence properties of apatite. For this purpose, the metallic substrates were treated in 5 M NaOH solution at 60 °C. Subsequently, the substrates were heat-treated at 600 °C for 1 h for consolidation of the sodium titanate hydrogel layer. Then, they were soaked in SBF for different periods of time. Finally, the possibility to use of PL monitoring as an effective method and early detection tool is discussed. According to the obtained results, it was concluded that the PL emission peak did not have any significant shift to the shorter or higher wavelengths, and the PL intensity increased as the exposure time increased. This research proved that the observed inherent PL of the newly formed apatite coatings might be of specific interest for histological probing and bone remodelling monitoring. Copyright © 2011 Elsevier B.V. All rights reserved.

Taking Stock and Taking Steps: The Case for an Adolescent Version of the Short-Assessment of Risk and Treatability.

Science.gov (United States)

Viljoen, Jodi L; Cruise, Keith R; Nicholls, Tonia L; Desmarais, Sarah L; Webster, Christopher

2012-01-01

The field of violence risk assessment has matured considerably, possibly advancing beyond its own adolescence. At this point in the field's evolution, it is more important than ever for the development of any new device to be accompanied by a strong rationale and the capacity to provide a unique contribution. With this issue in mind, we first take stock of the field of adolescent risk assessment in order to describe the rapid progress that this field has made, as well as the gaps that led us to adapt the Short-Term Assessment of Risk and Treatability (START; Webster, Martin, Brink, Nicholls, & Desmarais, 2009) for use with adolescents. We view the Short-Term Assessment of Risk and Treatability: Adolescent Version (START:AV; Nicholls, Viljoen, Cruise, Desmarais, & Webster, 2010; Viljoen, Cruise, Nicholls, Desmarais, & Webster, in progress) as complementing other risk measures in four primary ways: 1) rather than focusing solely on violence risk, it examines broader adverse outcomes to which some adolescents are vulnerable (including self-harm, suicide, victimization, substance abuse, unauthorized leave, self-neglect, general offending); 2) it places a balanced emphasis on adolescents' strengths; 3) it focuses on dynamic factors that are relevant to short-term assessment, risk management, and treatment planning; and 4) it is designed for both mental health and justice populations. We describe the developmentally-informed approach we took in the adaptation of the START for adolescents, and outline future steps for the continuing validation and refinement of the START:AV.

Appearance of cell-adhesion factor in osteoblast proliferation and differentiation of apatite coating titanium by blast coating method.

Science.gov (United States)

Umeda, Hirotsugu; Mano, Takamitsu; Harada, Koji; Tarannum, Ferdous; Ueyama, Yoshiya

2017-08-01

We have already reported that the apatite coating of titanium by the blast coating (BC) method could show a higher rate of bone contact from the early stages in vivo, when compared to the pure titanium (Ti) and the apatite coating of titanium by the flame spraying (FS) method. However, the detailed mechanism by which BC resulted in satisfactory bone contact is still unknown. In the present study, we investigated the importance of various factors including cell adhesion factor in osteoblast proliferation and differentiation that could affect the osteoconductivity of the BC disks. Cell proliferation assay revealed that Saos-2 could grow fastest on BC disks, and that a spectrophotometric method using a LabAssay TM ALP kit showed that ALP activity was increased in cells on BC disks compared to Ti disks and FS disks. In addition, higher expression of E-cadherin and Fibronectin was observed in cells on BC disks than Ti disks and FS disks by relative qPCR as well as Western blotting. These results suggested that the expression of cell-adhesion factors, proliferation and differentiation of osteoblast might be enhanced on BC disks, which might result higher osteoconductivity.

Incorporation of cesium into phosphates of apatitic and rhabdophane lattices. Application to the conditioning of separated radionuclides; Incorporation du cesium dans des phosphates de structure apatitique et rhabdophane. Application au conditionnement des radionucleides separes

Energy Technology Data Exchange (ETDEWEB)

Campayo, L

2003-04-01

Two phosphate-based materials were investigated for cesium immobilization after its partitioning from spent nuclear fuel: apatites and rhabdophanes. The incorporation of cesium into the apatitic lattice creates steric stresses. These stresses induce the formation of secondary phases which are rapidly leached. The effectiveness of the cesium immobilization in this material is not therefore validated. A second phosphate CsCaNd(PO{sub 4}){sub 2} was consistently found at the end of the leach test and its properties were further characterized. The structure of CsCaNd(PO{sub 4}){sub 2}, which is rhabdophane-like, is made of large channels which enable the incorporation of the largest alkaline cations. The synthesis involves two intermediates: the monazite, NdPO{sub 4}, and a soluble phosphate, CsCaPO{sub 4}. The study of a rhabdophane with 10 wt.% of cesium reveals satisfactory intrinsic properties: a thermal stability up to 1100 C and a leach rate of 10{sup -2} g/(m{sup 2}.d). The next step will be to improve the reaction yield. (author)

Demonstration testing and evaluation of in situ soil heating

International Nuclear Information System (INIS)

Sresty, G.C.

1994-01-01

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

Synthesis of functionally graded bioactive glass-apatite multistructures on Ti substrates by pulsed laser deposition

International Nuclear Information System (INIS)

Tanaskovic, D.; Jokic, B.; Socol, G.; Popescu, A.; Mihailescu, I.N.; Petrovic, R.; Janackovic, Dj.

2007-01-01

Functionally graded glass-apatite multistructures were synthesized by pulsed laser deposition on Ti substrates. We used sintered targets of hydroxyapatite Ca 10 (PO 4 ) 6 (OH) 2 , or bioglasses in the system SiO 2 -Na 2 O-K 2 O-CaO-MgO-P 2 O 5 with SiO 2 content of either 57 wt.% (6P57) or 61 wt.% (6P61). A UV KrF* (λ = 248 nm, τ > 7 ns) excimer laser source was used for the multipulse laser ablation of the targets. The hydroxyapatite thin films were obtained in H 2 O vapors, while the bioglass layers were deposited in O 2 . Thin films of 6P61 were deposited in direct contact with Ti, because Ti and this glass have similar thermal expansion behaviors, which ensure good bioglass adhesion to the substrate. This glass, however, is not bioactive, so yet more depositions of 6P57 bioglass and/or hydroxyapatite thin films were performed. All structures with hydroxyapatite overcoating were post-treated in a flux of water vapors. The obtained multistructures were characterized by various techniques. X-ray investigations of the coatings found small amounts of crystalline hydroxyapatite in the outer layers. The scanning electron microscopy analyses revealed homogeneous coatings with good adhesion to the Ti substrate. Our studies showed that the multistructures we had obtained were compatible with further use in biomimetic metallic implants with glass-apatite coating applications

Raman spectral, elemental, crystallinity, and oxygen-isotope variations in conodont apatite during diagenesis

Science.gov (United States)

Zhang, Lei; Cao, Ling; Zhao, Laishi; Algeo, Thomas J.; Chen, Zhong-Qiang; Li, Zhihong; Lv, Zhengyi; Wang, Xiangdong

2017-08-01

Conodont apatite has long been used in paleoenvironmental studies, often with minimal evaluation of the influence of diagenesis on measured elemental and isotopic signals. In this study, we evaluate diagenetic influences on conodonts using an integrated set of analytical techniques. A total of 92 points in 19 coniform conodonts from Ordovician marine units of South China were analyzed by micro-laser Raman spectroscopy (M-LRS), laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS), high-resolution X-ray microdiffraction (HXRD), and secondary ion mass spectrometry (SIMS). Each conodont element was analyzed along its full length, including the albid crown, hyaline crown, and basal body, in either a whole specimen (i.e., reflecting the composition of its outer layer) or a split specimen (i.e., reflecting the composition of its interior). In the conodonts of this study, the outer surfaces consist of hydroxyfluorapatite and the interiors of strontian hydroxyfluorapatite. Ionic substitutions resulted in characteristic Raman spectral shifts in the position (SS1) and width (SS2) of the ν1-PO43- stretching band. Although multiple elements were enriched (Sr2+, Mg2+) and depleted (Fe3+, Mn2+, Ca2+) during diagenesis, geochemical modeling constraints and known Raman spectral patterns suggest that Sr uptake was the dominant influence on diagenetic redshifts of SS1. All study specimens show lower SS2 values than modern bioapatite and synthetic apatite, suggesting that band width decreases with time in ancient bioapatite, possibly through an annealing process that produces larger, more uniform crystal domains. Most specimens consist mainly of amorphous or poorly crystalline apatite, which is inferred to represent the original microstructure of conodonts. In a subset of specimens, some tissues (especially albid crown) exhibit an increased degree of crystallinity developed through aggrading neomorphism. However, no systematic relationship was observed between

Incorporation of iodine into calcium phosphates with apatitic structure

International Nuclear Information System (INIS)

Coulon, Antoine

2014-01-01

In order to avoid the release of 129 I (long-lived intermediate-level waste) in the environment, we describe a novel material incorporating iodine under the form of iodate in a calcium phosphate based hydroxyapatite. This material is prepared by two synthetic processes: a wet precipitation route followed by a spark plasma sintering and a cementitious route. A high iodine content (with a maximum incorporation rate of 10 wt.%) is reached for both processes, by incorporation of the iodate in the apatitic structure. A monolith with relative density of 88.6% was obtained after shaping of the precipitated powders by spark plasma sintering. This material reveals satisfactory leaching properties, with an initial leaching rate in pure water at 50 C of 10 -2 g.m -2 .j -1 , and a residual leaching rate at 50 C of 10 -5 g.m -2 .j -1 in underground water of potential geological repositories. All in all, this material is a potential candidate for the conditioning of radioactive iodine. (author) [fr

Influence of surface modification on the apatite formation and corrosion behavior of Ti and Ti-15Mo alloy for biomedical applications

Energy Technology Data Exchange (ETDEWEB)

Sasikumar, Y. [Department of Chemistry, CEG Campus, Anna University, Chennai 600 025 (India); Rajendran, N., E-mail: nrajendran@annauniv.edu [Department of Chemistry, CEG Campus, Anna University, Chennai 600 025 (India)

2013-02-15

Commercially pure Ti and Ti-15Mo specimens were subjected to alkali-hydrogen peroxide and subsequent heat treatment to produce a nanoporous titanate gel layer with anatase phase. The surface morphology of the untreated, alkali-hydrogen peroxide treated and alkali-hydrogen peroxide heat treated specimens before and after 7 days of immersion in simulated body fluid was characterized using X-ray Diffractometer (XRD), Atomic Force Microscopy (AFM), Scanning Electron Microscopy (SEM) and Fourier Transform Infrared Spectroscopy (FT-IR). The formation of nanoporous titanate gel layer and the growth of apatite layer over the surface modified specimens after 7 days of immersion in simulated body fluid were confirmed. Further, the electrochemical corrosion behavior of all the specimens was examined using potentiodynamic polarization and electrochemical impedance spectroscopic techniques. - Highlights: ► Simple thermochemical process for Cp-Ti and Ti-15Mo alloy. ► Formation of nanoporous titanate layer on surface facilitate apatite formation. ► Hydroxyapatite coated sample exhibited improved corrosion resistance.

The dissolution kinetics and apparent solubility of natural apatite in closed reactors at temperatures from 5 to 50 degrees C and pH from 1 to 6

Energy Technology Data Exchange (ETDEWEB)

Harouiya, N.; Chairat, C.; Kohler, S.J.; Gout, R.; Oelkers, E.H. [Univ Toulouse 3, CNRS, UMR 5563, F-31400 Toulouse (France); Chairat, C. [CEA, LCLT SECM DTCD, Lab Etud Comportement Long Terme, F-30207 Bagnols Sur Ceze, (France)

2007-07-01

The apparent solubility and dissolution rates of natural apatite were measured in closed-system reactors as a function of temperature from 5 to 50 degrees C and pH from 1 to 6. The temporal release rates of Ca, P, and F during the experiments are approximately consistent with stoichiometric dissolution in all experiments. One advantage of closed-system experiments is that they allow determination of reactive fluid evolution and dissolution rates at far-from to near-to equilibrium conditions. Surface area normalized apatite dissolution rates, r, obtained in all experiments are consistent with r = A{sub A}a{sub H{sup +}}{sup n}exp(E{sub A}/RT)(1 -exp(-A/{sigma} RT)) where A{sub A} stands for a rate constant equal to 4 * 10{sup -3} mol/cm{sup 2}/s, a{sub H{sup +}}) denotes the activity of the aqueous H{sup +}, n designates a reaction order equal to 0.6, E{sub A} symbolizes an activation energy equal to 11.0 kcal/mol, A refers to the chemical affinity of the dissolving apatite, {sigma} stands for Temkin's average stoichiometric number equal to 5; R designates the gas constant, and T represents absolute temperature. Logarithms of apparent equilibrium constants obtained from experiments performed at 3 {<=} pH {<=} 5.6 for the apatite dissolution reaction: Ca{sub 5}(PO{sub 4}){sub 3}F + 3H{sup +} = 5Ca{sup 2+} + 3HPO{sub 4}{sup 2-} + F{sup -} are found to be - 29.5 {+-} 0.6, - 29.4 {+-} 0.9 and - 29.9 {+-} 1.3 at 5, 25, and 50 degrees C, respectively. (authors)

MECHANISMS CONTROLLING Ca ION RELEASE FROM SOL-GEL DERIVED IN SITU APATITE-SILICA NANOCOMPOSITE POWDER

Directory of Open Access Journals (Sweden)

Seyed Mohsen Latifi

2015-03-01

Full Text Available Ca ion release from bioactive biomaterials could play an important role in their bioactivity and osteoconductivity properties. In order to improve hydroxyapatite (HA dissolution rate, in situ apatite-silica nanocomposite powders with various silica contents were synthesized via sol-gel method and mechanisms controlling the Ca ion release from them were investigated. Obtained powders were characterized by X-ray diffraction (XRD and transmission electron spectroscopy (TEM techniques, acid dissolution test, and spectroscopy by atomic absorption spectrometer (AAS. Results indicated the possible incorporation of (SiO44- into the HA structure and tendency of amorphous silica to cover the surface of HA particles. However, 20 wt. % silica was the lowest amount that fully covered HA particles. All of the nanocomposite powders showed more Ca ion release compared with pure HA, and HA - 10 wt. % silica had the highest Ca ion release. The crystallinity, the crystallite size, and the content of HA, along with the integrity, thickness, and ion diffusion possibility through the amorphous silica layer on the surface of HA, were factors that varied due to changes in the silica content and were affected the Ca ion release from nanocomposite powders.

Adsorption of Pb(II) present in aqueous solution on calcium, strontium and barium hydroxy apatites; Adsorcion de Pb(II) presente en solucion acuosa sobre hidroxiapatitas de calcio, estroncio y bario

Energy Technology Data Exchange (ETDEWEB)

Vilchis G, J.

2013-07-01

Calcium, strontium and barium hydroxy apatites were successfully synthesized by chemical precipitation method, the obtained powders were characterized by the techniques of X-ray diffraction (XRD), scanning electron microscopy (Sem), semi-quantitative elemental analysis (EDS), infrared spectroscopy (IR), and N{sub 2} physisorption studies, complementary to these analytical techniques, was determined the surface fractal dimension (Df), and the amount of surface active sites of the materials, in order to know application as ceramic for water remediation. The ability of Pb(II) ion adsorption present in aqueous solution on the hydroxy apatites synthesized by batch type experiments was studied as a function of contact time, concentration of the adsorbate and temperature. The maximum lead adsorption efficiencies obtained were 0.31, 0.32 and 0.26 mg/g for calcium, strontium and barium hydroxy apatites respectively, achieved an equilibrium time of 20 minutes in the three solid-liquid systems studied. Experimental data were adequately adjusted at the adsorption kinetic model pseudo-second order, for the three cases. Moreover, experimental data of the strontium and calcium hydroxy apatites were adjusted to the Langmuir adsorption isotherm, indicating that the adsorption was through a monolayer, whereas barium hydroxyapatite was adjusted to the Freundlich adsorption isotherm, indicating a multilayer adsorption. The thermodynamic parameters obtained during adsorption studies as a function of temperature showed physisorption, exothermic and spontaneous processes respectively. The results showed that the calcium hydroxyapatite, strontium and barium are an alternative for the Pb(II) ion adsorption present in wastewaters. (Author)

Best management practices plan for Phase II of the Bear Creek Valley treatability study, Oak Ridge Y-12 Plant, Oak Ridge, Tennessee

International Nuclear Information System (INIS)

1997-09-01

The Oak Ridge Y-12 Plant is currently under a Federal Agreement to define soil and groundwater contamination and develop remedies to protect human health and the environment. The western end of the site is known to have a former nitric acid disposal pit that has been remediated and capped. Remedial investigation data indicate this pit was a source of nitrate, uranium, technetium, and other metals contamination in groundwater. The downgradient receptor of this contamination includes Bear Creek and its tributaries. A feasibility study is under way to develop a remedy to prevent further contaminant migration to this receptor. To support the feasibility study, the treatability study is being completed to examine groundwater treatment at the S-3 site. This document serves as the top-level command medium for Phase II of the Bear Creek Valley (BCV) Treatability Study and, as such, will be the primary resource for management and implementation of field activities. Many of the details and standard operating procedures referred to herein can be found in other Lockheed Martin Energy Systems, Inc. (Energy Systems), documents. Several supporting documents specific to this project are also cited. These include the Sampling and Analysis Plan (SAP), the Health and Safety Plan (HASP), and the Waste Management Plan (WMP)

Cooling and erosion history of the Krkonoše Piedmont Basin (Bohemian Massif, Czech Republic) interpreted from apatite fission-track analysis

Czech Academy of Sciences Publication Activity Database

Svojtka, Martin; Filip, Jiří; Martínek, K.

2005-01-01

Roč. 7, - (2005), s. 4925-4926 ISSN 1607-7962. [European Geosciences Union, General Assembly. 24.04.2005-29.04.2005, Wien] R&D Projects: GA AV ČR KJB3111305 Institutional research plan: CEZ:AV0Z30130516 Keywords : Krkonoše * apatite * fission-track Subject RIV: DB - Geology ; Mineralogy

Using Apatite to Model Chlorine Contents of High SiO2 Magmas: An Enhanced Methodological Approach

Science.gov (United States)

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"bearing magmatic systems.

Emplacement time of Salai Patai carbonatite, Malakand, Pakistan, from fission track dating of zircon and apatite

International Nuclear Information System (INIS)

Qureshi, A.A.; Khan, H.A.

1991-01-01

Based on fission track dating of zircon and apatite, the emplacement history of Salai Patai carbonatite has been traced. It has been estimated that the carbonatite was emplaced along the thrust plane associated with the Indian-Eurasian plate collision during the Oligocene period followed by some thermal/tectonic episode during Early Miocene. This negates the previous proposal that all carbonatites found in Pakistan are a part of a 200 km long alkaline province associated with the rifting of Peshawar Valley during Late Cretaceous or early tertiary. (author)

EPR dating CO2- sites in tooth enamel apatites by ENDOR and triple resonance

International Nuclear Information System (INIS)

Vugman, N.V.; Rigby, S.E.J.

1995-01-01

In this work we combine electron paramagnetic resonance (EPR), high-resolution electron nucleus double resonance (ENDOR) and general triple resonance (GTR) spectroscopies, to study the local environment of the CO 2 - groups created by ionizing radiation in fossil tooth enamel. We demonstrate that the CO 2 - groups occupy slightly modified phosphate sites in the hydroxyapatite lattice. In quaternary shark enamel we found these groups to be interacting with water molecules in the apatite channels. The absence of water molecules as first neighbours in mammalian samples indicate, however, that these molecules are not significantly responsible for the stabilization of CO 2 - dating centers in enamel. (author)

Crystallinity and compositional changes in carbonated apatites: Evidence from 31P solid-state NMR, Raman, and AFM analysis

Science.gov (United States)

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.

2013-10-01

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 31P NMR spectral parameters were investigated in a series of synthetic B-type carbonated apatites (CAps). Inverse 31P NMR linewidth and inverse Raman PO43-ν1 bandwidth were both correlated with powder XRD c-axis crystallinity over the 0.3-10.3 wt% CO32- 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 31P NMR chemical shift frequency and the Raman phosphate ν1 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.

Microchemical and structural regular variability of apatites in 'overbuilt' enamel and dentin of human molar teeth

International Nuclear Information System (INIS)

Kuczumow, A.; Nowak, J.; ChaLas, R.

2011-01-01

The aim of a recent paper was to recognize the chemical and structural changes in apatites, which form both the enamel and the dentin of the human tooth. The aim was achieved by scrutinizing the linear elemental profiles along the cross-sections of human molar teeth. Essentially, the task was accomplished with the application of the Electron Probe Microanalysis method and with some additional studies by Micro-Raman spectrometry. All the trends in linear profiles were strictly determined. In the enamel zone they were either increasing or decreasing curves of exponential character. The direction of the investigations was to start with the tooth surface and move towards the dentin-enamel junction (DEJ). The results of the elemental studies were more visible when the detected material was divided, in an arbitrary way, into the prevailing 'core' enamel (∼93.5% of the total mass) and the remaining 'overbuilt' enamel. The material in the 'core' enamel was fully stable, with clearly determined chemical and mechanical features. However, the case was totally different in the 'overbuilt enamel', with dynamic changes in the composition. In the 'overbuilt' layer Ca, P, Cl and F profiles present the decaying distribution curves, whereas Mg, Na, K and CO 3 2- present the growing ones. Close to the surface of the tooth the mixture of hydroxy-, chlor- and fluor-apatite is formed, which is much more resistant than the rest of the enamel. On passing towards the DEJ, the apatite is enriched with Na, Mg and CO 3 2- . In this location, three of six phosphate groups were substituted with carbonate groups. Simultaneously, Mg is associated with the hydroxyl groups around the hexad axis. In this way, the mechanisms of exchange reactions were established. The crystallographic structures were proposed for new phases located close to DEJ. In the dentin zone, the variability of elemental profiles looks different, with the most characteristic changes occurring in Mg and Na concentrations. Mg

Martensitic transformation and residual stresses after thermomechanical treatment of heat treatable steel 42CrMo4 (SAE 4140)

Energy Technology Data Exchange (ETDEWEB)

Weise, A. [Technische Univ. Chemnitz-Zwickau, Chemnitz (Germany). Fakultaet fuer Maschinenbau und Verfahrenstechnik; Fritsche, G. [Technische Univ. Chemnitz-Zwickau, Chemnitz (Germany). Fakultaet fuer Maschinenbau und Verfahrenstechnik

1996-01-01

The influence of thermomechanical deformation on the residual stresses caused by quenching in bar shaped specimens of heat treatable steel 42CrMo4 has been investigated using a mechanical method for determining the distribution of residual stresses of the first kind. The results obtained show that the residual stress distribution after quenching is affected by the strengthening and softening of the austenite as a result of deformation and recrystallization and the modified transformation behaviour in martensite stage. An attempt is made to discuss qualitatively the influence of these changes on the generation of residual stresses as compared to results obtained after conventional hardening. (orig.).

Martensitic transformation and residual stresses after thermomechanical treatment of heat treatable steel 42CrMo4 (SAE 4140)

International Nuclear Information System (INIS)

Weise, A.; Fritsche, G.

1996-01-01

The influence of thermomechanical deformation on the residual stresses caused by quenching in bar shaped specimens of heat treatable steel 42CrMo4 has been investigated using a mechanical method for determining the distribution of residual stresses of the first kind. The results obtained show that the residual stress distribution after quenching is affected by the strengthening and softening of the austenite as a result of deformation and recrystallization and the modified transformation behaviour in martensite stage. An attempt is made to discuss qualitatively the influence of these changes on the generation of residual stresses as compared to results obtained after conventional hardening. (orig.)

Possible Roles of Fluoride and Carbonate in Biochemical Carbonated Apatite Formation

Science.gov (United States)

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.

Using of natural radioactivity for determination of phosphorus content in phosphate rocks, apatites and superphosphates

Energy Technology Data Exchange (ETDEWEB)

Magas, S; Kasprzak, K S; Gorski, Z [Politechnika Poznanska (Poland). Inst. Chemii Podstawowej

1980-01-01

A quick radiometric method of determination of phosphorus content in natural phosphate rocks, apatites and phosphorus fertilizers, obtained from them has been developed on the basis of uranium and the products of its radioactive decay contained in these materials. The uranium content in these materials amounts to 0.01/0.02%, and is for a given deposit proportional to the phosphorus content. The method is well fitted for laboratory quick determination of phosphorus content in raw-materials and products in factories producing phosphorus fertilizers and makes possible the automation of process and proportioning of sulphuric acid in production of superphosphates.

Comparative in vitro studies on disodium EDTA effect with and without Proteus mirabilis on the crystallization of carbonate apatite and struvite

Science.gov (United States)

Prywer, Jolanta; Olszynski, Marcin; Torzewska, Agnieszka; Mielniczek-Brzóska, Ewa

2014-06-01

Effect of disodium EDTA (salt of ethylenediamine tetraacetic acid) on the crystallization of struvite and carbonate apatite was studied. To evaluate such an effect we performed an experiment of struvite and carbonate apatite growth from artificial urine. The crystallization process was induced by Proteus mirabilis to mimic the real urinary tract infection, which usually leads to urinary stone formation. The results demonstrate that disodium EDTA exhibits the effect against P. mirabilis retarding the activity of urease - an enzyme produced by these microorganisms. The spectrophotometric results demonstrate that, with and without P. mirabilis, the addition of disodium EDTA increases the induction time and decreases the growth efficiency compared to the baseline (without disodium EDTA). These results are discussed from the standpoint of speciation of complexes formed in the solution of artificial urine in the presence of disodium EDTA. The size of struvite crystals was found to decrease in the presence of disodium EDTA. However, struvite crystals are larger in the presence of bacteria while the crystal morphology and habit remain unchanged.

Urea cycle disorders: a life-threatening yet treatable cause of metabolic encephalopathy in adults.

Science.gov (United States)

Blair, Nicholas F; Cremer, Philip D; Tchan, Michel C

2015-02-01

Urea cycle disorders are inborn errors of metabolism that, in rare cases, can present for the first time in adulthood. We report a perplexing presentation in a woman 4 days postpartum of bizarre and out-of-character behaviour interspersed with periods of complete normality. Without any focal neurological signs or abnormality on initial investigations, the diagnosis became clear with the finding of a significantly elevated plasma ammonia level, just as she began to deteriorate rapidly. She improved following intravenous dextrose and lipid emulsion, together with sodium benzoate, arginine and a protein-restricted diet. She remains well 12 months later with no permanent sequelae. Whilst this is a rare presentation of an uncommon disease, it is a treatable disorder and its early diagnosis can prevent a fatal outcome. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Long-term landscape evolution of the South Atlantic "passive" continental margin in Eastern Argentina using apatite fission-track thermochronology

Science.gov (United States)

Pfister, Sabrina; Kollenz, Sebastian; Glasmacher, Ulrich A.

2015-04-01

spontaneous fission-tracks and were used to test geological t-T models against the AFT data set. These models will lead to a more detailed insight on the cooling history and tectonic activities in the research area. In addition there will be an outlook on further models including AFT, ZrFT and ZrHe data, which show that the Sierras Septentrionales seems to be influenced by the folding and wrenching of the neighboring Sierras Australes (Rosello et al. 1997). References Cingolani, C. A. The Tandilia System of Argentina as a southern extension of the Río de la Plata craton: an overview. International Journal of Earth Sciences 100, 221-242 (2011). Demoulin, A., Zarate, M., Rabassa, J. Longterm landscape development: a perspective from the southern Buenos Aires ranges of east central Argentina. Journal of South American Earth Sciences 19, 193-204 (2005). Ketcham, R. A. Forward and inverse modeling of low-temperature thermochronometry data, in Low-Temperature Thermochronology: Techniques, Interpretations, and Applications (eds. by Reiners, P. W. & Ehlers, T. A.) 275-314 (Mineralogical Society of America/Geochemical Society Reviews in Mineralogy and Geochemistry, Chantilly, Virginia, 2005). Ketcham, R. A., et al. Improved modeling of fission-track annealing in apatite. American Mineralogist, 92, 789-798 (2007). Ketcham, R. A., Donelick, R. A., Balestrieri, M. L., Zattin, M. Reproducibility of apatite fission-track length data and thermal history reconstruction, Earth and Planetary Science Letters 284, 504-515 (2009). Rossello, E.A.; Massabie, C.; Lopez- Gamundi, O.R.; Cobbold, P.R.; Gapais, d.; 1997: Late Paleozoic transpression in Buenos Aires and northeast Patagonia ranges, Argentina Journal of South American Earth Sciences, 10 (5-6), pp.389-402. Zalba, P. E., Manassero, M., La Verret, E., Beaufort, D., Meunier, A., Morosi, M., Segovia, L. Middle Permian telodiagenetic processes in Neoproterozoic sequences, Tandilia System, Argentina. Int. J. of Sed. Res. 77, 525-538 (2007).

Process evaluation and treatability study of wastewater in a textile dyeing industry

Energy Technology Data Exchange (ETDEWEB)

Mazumder, Debabrata [Civil Engineering Department, Bengal Engineering and Science University, Shibpur, P.O. - Botanic Garden, Horah, West Bengal - 711 103 (India)

2011-07-01

The process was investigated in a textile dying unit and subsequently wastewater generation profile was studied for the development of a viable treatment. The dyeing unit under the study generated a considerable volume of wastewater containing inorganic chemicals and organic reactive green dye. Chemical oxygen demand (COD) resulting from all the chemically oxidizible substances and the residual color of the dye were targeted for removal. The wastewater samples were collected from different sub-processes and then characterized for the parameters viz. pH, Total solid, Suspended solid, Dissolved solid, COD and Alkalinity. A composite wastewater sample was prepared according to the measured wastewater discharge from various unit operations and used for treatability study. In the first stage, coagulation-flocculation with alum and chemical oxidation with bleaching powder were performed separately. Subsequently, adsorption study was conducted with crushed burnt coal (C.B.C.) on the composite wastewater, initially treated with 10% bleaching powder solution. After several trials, this combination was found to be effective for a C.B.C. content of 10% under a contact period of 90 minutes, which showed 100% colour and about 95% COD removal.

Extraction and characterisation of apatite- and tricalcium phosphate-based materials from cod fish bones

Energy Technology Data Exchange (ETDEWEB)

Piccirillo, C.; Silva, M.F. [CBQF/Escola Superior de Biotecnologia, Universidade Catolica Portuguesa, Porto (Portugal); Pullar, R.C. [Dept. Engenharia de Materiais e Ceramica/CICECO, Universidade de Aveiro, Aveiro (Portugal); Braga da Cruz, I. [CBQF/Escola Superior de Biotecnologia, Universidade Catolica Portuguesa, Porto (Portugal); WeDoTech, CiDEB/Escola Superior de Biotecnologia, Universidade Catolica Portuguesa, Porto (Portugal); Jorge, R. [WeDoTech, CiDEB/Escola Superior de Biotecnologia, Universidade Catolica Portuguesa, Porto (Portugal); Pintado, M.M.E. [CBQF/Escola Superior de Biotecnologia, Universidade Catolica Portuguesa, Porto (Portugal); Castro, P.M.L., E-mail: plcastro@porto.ucp.pt [CBQF/Escola Superior de Biotecnologia, Universidade Catolica Portuguesa, Porto (Portugal)

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 Degree-Sign C, giving a biphasic material of hydroxyapatite and tricalcium phosphate (Ca{sub 10}(PO{sub 4}){sub 6}(OH){sub 2} and {beta}-Ca(PO{sub 4}){sub 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 (Ca{sub 10}(PO{sub 4}){sub 6}Cl{sub 2}) and fluorapatite (Ca{sub 10}(PO{sub 4}){sub 6}F{sub 2}) were obtained using CaCl{sub 2} 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. - Highlights: Black-Right-Pointing-Pointer Apatite and calcium phosphate compounds extraction from cod fish bones Black-Right-Pointing-Pointer Bone calcination: biphasic material hydroxyapatite-calcium phosphate production Black-Right-Pointing-Pointer Bone pre-treatments in solution change the material composition. Black-Right-Pointing-Pointer Single phase materials (hydroxy-, chloro- or fluoroapatite) are obtained. Black-Right-Pointing-Pointer Concentration of other elements (Na, F, Cl) suitable for biomedical applications.

Fabrication and Physical Evaluation of Gelatin-Coated Carbonate Apatite Foam

Directory of Open Access Journals (Sweden)

Kanae Hara

2016-08-01

Full Text Available Carbonate apatite (CO3Ap foam has gained much attention in recent years because of its ability to rapidly replace bone. However, its mechanical strength is extremely low for clinical use. In this study, to understand the potential of gelatin-reinforced CO3Ap foam for bone replacement, CO3Ap foam was reinforced with gelatin and the resulting physical characteristics were evaluated. The mechanical strength increased significantly with the gelatin reinforcement. The compressive strength of gelatin-free CO3Ap foam was 74 kPa whereas that of the gelatin-reinforced CO3Ap foam, fabricated using 30 mass % gelatin solution, was approximately 3 MPa. Heat treatment for crosslinking gelatin had little effect on the mechanical strength of the foam. The gelatin-reinforced foam did not maintain its shape when immersed in a saline solution as this promoted swelling of the gelatin; however, in the same conditions, the heat-treated gelatin-reinforced foam proved to be stable. It is concluded, therefore, that heat treatment is the key to the fabrication of stable gelatin-reinforced CO3Ap foam.

New bismuth calcium oxysilicate with apatite structure: Synthesis and structural characterization

International Nuclear Information System (INIS)

Uvarov, Vladimir; Shenawi-Khalil, Sanaa; Popov, Inna

2010-01-01

New bismuth calcium silicon oxide Ca 4 Bi 4.3 (SiO 4 )(HSiO 4 ) 5 O 0.95 , with apatite structure has been synthesized. The structure was refined from powder X-ray diffraction data. The refinement revealed that the phase has P6 3 /m (176) space group with unit cell parameters a=b=9.6090(7) A, c=7.0521(7) A, V=563.9 A 3 and c/a=0.734. The R wp factor at Rietveld refinement was equal to 0.082. The synthesized phase has an unusual quantity of cation vacancies in a crystal lattice. Mechanisms of compensation of the excess charge of a lattice are considered and checked experimentally using the FT-IR spectroscopy, the thermal analysis and the XPS analysis. - Graphical abstract: The fragment Ca 4 Bi 4.3 (SiO 4 )(HSiO 4 ) 5 O 0.95 structure along c-axis in polygonal mode.

The influence of parameters of A-type carbonated apatites synthesis on radiation dose response

International Nuclear Information System (INIS)

Oliveira, Liana Macedo de; Lopes, Ricardo Tadeu

2000-01-01

The aim of this work is the investigation of dose response of A-type carbonated apatites prepared in different conditions. Irradiated samples prepared with carbonate content of 1.45 to 4.84% are studied by using electron paramagnetic resonance (EPR). The EPR spectra are mainly constituted of lines associated to axial CO 2 - species (g perp = 2.0028 and g // = 1.9973) and CO 3 - species (g 1 = 2,0170, g 2 = 2,0090 e g 3 = 2,0041). The production of CO 2 - species on gamma irradiation depends on the carbonate concentration and the hydroxyapatite stoichiometry. The lowest dose detection limit was achieved with stoichiometric samples and carbonate content around of 3.7%. (author)

The dependence of thermoluminescence sensitivity upon the temperature of irradiation in meteorites and in terrestrial apatites

International Nuclear Information System (INIS)

Durrani, S.A.; Al-Khalifa, I.J.M.

1990-01-01

Measurements are reported on the TL sensitivity (i.e. TL glow output per unit γ ray test dose) of meteoritic specimens as well as terrestrial fluor- and chlor-apatites, as a function of irradiation temperature (T irr ). The irradiation temperatures ranged from liquid nitrogen to room temperature (77 - 293 K). A kilocurie 60 Co γ ray source was used to deliver test doses of 400 Gy (40 krad) and 40 (4 krad) to the various samples. A strong dependence of the TL sensitivity upon the temperature of irradiation was noted in the case of Kirin meteorite: its TL sensitivity (for the 493 K readout peak) decreased by a factor of ∼ 2 when T irr rose from liquid nitrogen (77 K) to dry ice in acetone (197 K) temperature, in the case of both 400 Gy and 40 Gy γ ray doses. In the case of the Antarctic meteorite specimen (ALHA 77182.13), there was a smaller effect, viz. a fall of ∼ 14% in the TL output corresponding to dry ice and higher irradiating temperatures as compared to the 77 K irradiation. For chlorapatite, the TL sensitivity decreased monotonically with increasing temperature for both the 563 K and the 448 K glow peaks. For the fluorapatite, the effect of reduced response was observed only between -17 0 C (256 K) and room temperature (293 K). Both the theoretical and the practical implications of these observations are discussed. (author)

Ionic conductivity and fuel cell properties of apatite-type lanthanum silicates doped with Mg and containing excess oxide ions

Energy Technology Data Exchange (ETDEWEB)

Yoshioka, Hideki [Hyogo Prefectural Institute of Technology, 3-1-12 Yukihira-cho, Suma-ku, Kobe 654-0037 (Japan); Nojiri, Yoshihiro [Kyushu University, Department of Mechanical Engineering Science, Faculty of Engineering, Motooka 744, Nishi-ku, Fukuoka 819-0935 (Japan); Tanase, Shigeo [National Institute of Advanced Industrial Science and Technology, 1-8-31 Midorigaoka, Ikeda, Osaka 563-8577 (Japan)

2008-11-30

Enhancement of the ionic conductivity of lanthanum silicate-based apatites is examined with emphasis on optimizing the La composition and the Mg doping level at the same time. La{sub 10}Si{sub 5.8}Mg{sub 0.2}O{sub 26.8} and La{sub 9.8}Si{sub 5.7}Mg{sub 0.3}O{sub 26.4} show the highest level of the ionic conductivities among apatite silicates, 8.8 and 7.4 x 10{sup -} {sup 2} S cm{sup -} {sup 1} at 800 C, respectively, with a very low level of activation energy (0.42-0.43 eV). Their conductivities are higher than yttria stabilized zirconia (YSZ) below 900 C and even comparable to Sr and Mg doped lanthanum gallate (LSGM) below 550 C. A solid oxide fuel cell using La{sub 9.8}Si{sub 5.7}Mg{sub 0.3}O{sub 26.4} as an electrolyte with Ni-ceria cermet anode and Sr doped lanthanum cobaltite cathode exhibits a remarkable improvement in power generation compared to previous data using Pt electrodes. Structural investigation by the Rietveld analysis on the powder X-ray diffraction pattern shows significant enlargement of the bottleneck triangle sizes of the conduction channel with the Mg doping. (author)

AMPD2 Regulates GTP Synthesis and is Mutated in a Potentially-Treatable Neurodegenerative Brainstem Disorder

Science.gov (United States)

Akizu, Naiara; Cantagrel, Vincent; Schroth, Jana; Cai, Na; Vaux, Keith; McCloskey, Douglas; Naviaux, Robert K.; Vleet, Jeremy Van; Fenstermaker, Ali G.; Silhavy, Jennifer L.; Scheliga, Judith S.; Toyama, Keiko; Morisaki, Hiroko; Sonmez, Fatma Mujgan; Celep, Figen; Oraby, Azza; Zaki, Maha S.; Al-Baradie, Raidah; Faqeih, Eissa; Saleh, Mohammad; Spencer, Emily; Rosti, Rasim Ozgur; Scott, Eric; Nickerson, Elizabeth; Gabriel, Stacey; Morisaki, Takayuki; Holmes, Edward W.; Gleeson, Joseph G.

2013-01-01

Purine biosynthesis and metabolism, conserved in all living organisms, is essential for cellular energy homeostasis and nucleic acids synthesis. The de novo synthesis of purine precursors is under tight negative feedback regulation mediated by adenosine and guanine nucleotides. We describe a new distinct early-onset neurodegenerative condition resulting from mutations in the adenosine monophosphate deaminase 2 gene (AMPD2). Patients have characteristic brain imaging features of pontocerebellar hypoplasia (PCH), due to loss of brainstem and cerebellar parenchyma. We found that AMPD2 plays an evolutionary conserved role in the maintenance of cellular guanine nucleotide pools by regulating the feedback inhibition of adenosine derivatives on de novo purine synthesis. AMPD2 deficiency results in defective GTP-dependent initiation of protein translation, which can be rescued by administration of purine precursors. These data suggest AMPD2-related PCH as a new, potentially treatable early-onset neurodegenerative disease. PMID:23911318

A Holistic Model That Physicochemically Links Iron Oxide - Apatite and Iron Oxide - Copper - Gold Deposits to Magmas

Science.gov (United States)

Simon, A. C.; Reich, M.; Knipping, J.; Bilenker, L.; Barra, F.; Deditius, A.; Lundstrom, C.; Bindeman, I. N.

2015-12-01

Iron oxide-apatite (IOA) and iron oxide-copper-gold deposits (IOCG) are important sources of their namesake metals and increasingly for rare earth metals in apatite. Studies of natural systems document that IOA and IOCG deposits are often spatially and temporally related with one another and coeval magmatism. However, a genetic model that accounts for observations of natural systems remains elusive, with few observational data able to distinguish among working hypotheses that invoke meteoric fluid, magmatic-hydrothermal fluid, and immiscible melts. Here, we use Fe and O isotope data and high-resolution trace element (e.g., Ti, V, Mn, Al) data of individual magnetite grains from the world-class Los Colorados (LC) IOA deposit in the Chilean Iron Belt to elucidate the origin of IOA and IOCG deposits. Values of d56Fe range from 0.08‰ to 0.26‰, which are within the global range of ~0.06‰ to 0.5‰ for magnetite formed at magmatic conditions. Values of δ18O for magnetite and actinolite are 2.04‰ and 6.08‰, respectively, consistent with magmatic values. Ti, V, Al, and Mn are enriched in magnetite cores and decrease systematically from core to rim. Plotting [Al + Mn] vs. [Ti + V] indicates that magnetite cores are consistent with magmatic and/or magmatic-hydrothermal (i.e., porphyry) magnetites. Decreasing Al, Mn, Ti, V is consistent with a cooling trend from porphyry to Kiruna to IOCG systems. The data from LC are consistent with the following new genetic model for IOA and IOCG systems: 1) magnetite cores crystallize from silicate melt; 2) these magnetite crystals are nucleation sites for aqueous fluid that exsolves and scavenges inter alia Fe, P, S, Cu, Au from silicate melt; 3) the magnetite-fluid suspension is less dense that the surrounding magma, allowing ascent; 4) as the suspension ascends, magnetite grows in equilibrium with the fluid and takes on a magmatic-hydrothermal character (i.e., lower Al, Mn, Ti, V); 5) during ascent, magnetite, apatite and

Multiphase cooling and exhumation of the Krkonoše Piedmont Basin during Mesozoic - Cenozoic basin inversion based on apatite fission track analysis

Czech Academy of Sciences Publication Activity Database

Martínek, K.; Svojtka, Martin; Filip, Jiří

2008-01-01

Roč. 34, 4/6 (2008), s. 1353003-1353003 ISSN 0161-6951. [International Geological Congress /33./. 06.08.2008-14.08.2008, Oslo] R&D Projects: GA AV ČR KJB3111305 Institutional research plan: CEZ:AV0Z30130516 Keywords : fission track * apatite * Krkonoše Piedmont basin Subject RIV: DB - Geology ; Mineralogy

A prolonged Cenozoic erosional period in East Kunlun (Western China): Constraints of detrital apatite (U-Th)/He ages on the onset of mountain building along the northern margin of the Tibetan Plateau