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Sample records for boron enrichment plant

  1. Enrichment of boron 10

    International Nuclear Information System (INIS)

    Coutinho, C.M.M.; Rodrigues Filho, J.S.R.; Umeda, K.; Echternacht, M.V.

    1990-01-01

    A isotopic separation pilot plant with five ion exchange columns interconnected in series were designed and built in the IEN. The columns are charged with a strong anionic resin in its alkaline form. The boric acid solution is introduced in the separation columns until it reaches a absorbing zone length which is sufficient to obtain the desired boron-10 isotopic concentration. The boric acid absorbing zone movement is provided by the injection of a diluted hydrochloric acid solution, which replace the boric acid throughout the columns. The absorbing zone equilibrium length is proportional to its total length. The enriched boron-10 and the depleted boron are located in the final boundary and in the initial position of the absorbing zones, respectively. (author)

  2. Application of ICPMS for performance evaluation of boron enrichment plant at HWP, Manuguru

    International Nuclear Information System (INIS)

    Murthy, P.K.; Mohapatra, C.; Vithal, G.K.

    2011-01-01

    10 B enriched compounds are used in neutron control rod in Fast Breeder Reactors (FBR), Neutron Detector, Neutron Capture Therapy, and Neutron Shielding. Heavy Water Board (HWB) is given a mandate to produce enriched elemental boron which is being produced using Ion exchange chromatography and BF 3 - ether complex distillation methods. Ion Exchange Chromatography based Boron Enrichment Plant is operating at HWP, Manuguru. Ion Exchange Chromatography based process depends, besides other process parameters, on column run time and movement of band length. For effective process and quality control, it is necessary to analyze 10 B/ 11 B ratio in feed, process stream, waste and the product. 10 B/ 11 B ratio measurements are possible by Thermal Ionization Mass Spectrometer (TIMS) and Inductively Coupled Plasma Mass Spectrometer (ICPMS), the former offers better accuracy but takes longer analysis time whereas the later offers quick analysis of isotopic ratios and as well as trace metal impurities in the Boric acid

  3. Boron isotopic enrichment by displacement chromatography

    International Nuclear Information System (INIS)

    Mohapatra, K.K.; Bose, Arun

    2014-01-01

    10 B enriched boron is used in applications requiring high volumetric neutron absorption (absorption cross section- 3837 barn for thermal and 1 barn for 1 MeV fast neutron). It is used in fast breeder reactor (as control rod material), in neutron counter, in Boron Neutron Capture Therapy etc. Owing to very small separation factor, boron isotopic enrichment is a complex process requiring large number of separation stages. Heavy Water Board has ventured in industrial scale production of 10 B enriched boron using Exchange Distillation Process as well as Ion Displacement Chromatography Process. Ion Displacement Chromatography process is used in Boron Enrichment Plant at HWP, Manuguru. It is based on isotopic exchange between borate ions (B(OH) 4 - ) on anion exchange resin and boric acid passing through resin. The isotopic exchange takes place due to difference in zero point energy of 10 B and 11 B

  4. Boron enrichment in martian clay.

    Directory of Open Access Journals (Sweden)

    James D Stephenson

    Full Text Available We have detected a concentration of boron in martian clay far in excess of that in any previously reported extra-terrestrial object. This enrichment indicates that the chemistry necessary for the formation of ribose, a key component of RNA, could have existed on Mars since the formation of early clay deposits, contemporary to the emergence of life on Earth. Given the greater similarity of Earth and Mars early in their geological history, and the extensive disruption of Earth's earliest mineralogy by plate tectonics, we suggest that the conditions for prebiotic ribose synthesis may be better understood by further Mars exploration.

  5. Boron Enrichment in Martian Clay

    Science.gov (United States)

    Nagashima, Kazuhide; Freeland, Stephen J.

    2013-01-01

    We have detected a concentration of boron in martian clay far in excess of that in any previously reported extra-terrestrial object. This enrichment indicates that the chemistry necessary for the formation of ribose, a key component of RNA, could have existed on Mars since the formation of early clay deposits, contemporary to the emergence of life on Earth. Given the greater similarity of Earth and Mars early in their geological history, and the extensive disruption of Earth's earliest mineralogy by plate tectonics, we suggest that the conditions for prebiotic ribose synthesis may be better understood by further Mars exploration. PMID:23762242

  6. Boron Isotopes Enrichment via Continuous Annular Chromatography

    OpenAIRE

    Sağlam, Gonca

    2016-01-01

    ABSTRACT Boron has two stable isotopes namely 10B and 11B isotopes. The large cross section of 10B isotope for thermal neutrons is used for reactor control in nuclear fission reactors. The thermal neutrons absorption cross sections of pure 10B and 11B are 3837 and 0.005 barns respectively. In the literature, amongst others, batch elution chromatography techniques are reported for 10B isotope enrichment. This work focuses on continuous chromatographic 10B isotope separation system via continuo...

  7. Laser-induced photochemical enrichment of boron isotopes

    International Nuclear Information System (INIS)

    Freund, S.M.; Ritter, J.J.

    1976-01-01

    A boron trichloride starting material containing both boron-10 isotopes and boron-11 isotopes is selectively enriched in one or the other of these isotopes by a laser-induced photochemical method involving the reaction of laser-excited boron trichloride with either H 2 S or D 2 S. The method is carried out by subjecting a low pressure gaseous mixture of boron trichloride starting material and the sulfide to infrared radiation from a carbon dioxide TE laser. The wave length of the radiation is selected so as to selectively excite one or the other of boron-10 BCl 3 molecules or boron-11 BCl 3 molecules, thereby making them preferentially more reactive with the sulfide. The laser-induced reaction produces both a boron-containing solid phase reaction product and a gaseous phase containing mostly unreacted BCl 3 and small amounts of sulfhydroboranes. Pure boron trichloride selectively enriched in one of the isotopes is recovered as the primary product of the method from the gaseous phase by a multi-step recovery procedure. Pure boron trichloride enriched in the other isotope is recovered as a secondary product of the method by the subsequent chlorination of the solid phase reaction product followed by separation of BCl 3 from the mixture of gaseous products resulting from the chlorination

  8. Appraisal of SIMS applicability to boron studies in plants.

    Science.gov (United States)

    Dérue, Cedric; Gibouin, David; Verdus, Marie-Claire; Lefebvre, Fabrice; Demarty, Maurice; Ripoll, Camille; Thellier, Michel

    2002-07-15

    In the search for a new methodological approach applicable to the determination of the still poorly known primary role of boron in plant physiology, we have undertaken to appraise the potential of the SIMS method for the analytical imaging of the boron isotopes, (10)B and (11)B, at physiological concentrations in plants. With our own, CAMECA IMS4F SIMS ion analyser, and using O(2)(+) as primary ions for the detection of B(+) (plus (12)C(+) and (40)Ca(+)) secondary ions, we have been able to map quantitatively the two boron isotopes in control and boron-enriched plants, to evaluate boron concentrations at the level of individual cells and to determine boron isotopic ratios. This provides the opportunity to carry out the simultaneous labeling and imaging of boron, using enrichment with the stable isotopes, (10)B and (11)B. The method has also the potential for the simultaneous, quantitative detection of the boron isotopes and of the borate-binding sites in plant cells. Copyright 2002 Wiley-Liss, Inc.

  9. Isotopic Enrichment of Boron in the Sputtering of Boron Nitride with Xenon Ions

    Science.gov (United States)

    Ray, P. K.; Shutthanandan, V.

    1998-01-01

    An experimental study is described to measure the isotopic enrichment of boron. Xenon ions from 100 eV to 1.5 keV were used to sputter a boron nitride target. An ion gun was used to generate the ion beam. The ion current density at the target surface was approximately 30 microA/sq cm. Xenon ions impinged on the target surface at 50 deg angle to the surface normal. Since boron nitride is an insulator, a flood electron gun was used in our experiments to neutralize the positive charge buildup on the target surface. The sputtered secondary ions of boron were detected by a quadrupole mass spectrometer. The spectrometer entrance aperture was located perpendicular to the ion beam direction and 10 mm away from the target surface. The secondary ion flux was observed to be enriched in the heavy isotopes at lower ion energies. The proportion of heavy isotopes in the sputtered secondary ion flux was found to decrease with increasing primary ion energy from 100 to 350 eV. Beyond 350 eV, light isotopes were sputtered preferentially. The light isotope enrichment factor was observed to reach an asymptotic value of 1.27 at 1.5 keV. This trend is similar to that of the isotopic enrichment observed earlier when copper was sputtered with xenon ions in the same energy range.

  10. Atmospheric contribution to boron enrichment in aboveground wheat tissues.

    Science.gov (United States)

    Wang, Cheng; Ji, Junfeng; Chen, Mindong; Zhong, Cong; Yang, Zhongfang; Browne, Patrick

    2017-05-01

    Boron is an essential trace element for all organisms and has both beneficial and harmful biological functions. A particular amount of boron is discharged into the environment every year because of industrial activities; however, the effects of environmental boron emissions on boron accumulation in cereals has not yet been estimated. The present study characterized the accumulation of boron in wheat under different ecological conditions in the Yangtze River Delta (YRD) area. This study aimed to estimate the effects of atmospheric boron that is associated with industrial activities on boron accumulation in wheat. The results showed that the concentrations of boron in aboveground wheat tissues from the highly industrialized region were significantly higher than those from the agriculture-dominated region, even though there was no significant difference in boron content in soils. Using the model based on the translocation coefficients of boron in the soil-wheat system, we estimated that the contribution of atmosphere to boron accumulation in wheat straw in the highly industrialized region exceeded that in the agriculture-dominated region by 36%. In addition, from the environmental implication of the model, it was estimated that the development of boron-utilizing industries had elevated the concentration of boron in aboveground wheat tissues by 28-53%. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. The effect of soluble boron on the burnup at different enrichments and assemblies

    International Nuclear Information System (INIS)

    Guenduez, G.; Ajwah, Y.

    1989-01-01

    The effect of boron on the optimum burnup was investigated at different assemblies for enriched fuels. As the enrichment increases, an alternation in the assembly type is needed for the optimum specific power. This alternation can be made at lower enrichments due to presence of boron. The optimum specific power is shifted toward the high enrichment fuel when the assembly number is increased. If a fuel of high enrichment is first burnt in a highly hardened neutron spectrum and later in a softer spectrum than an improvement in power is achieved. (orig.)

  12. A high boronate avidity monolithic capillary for the selective enrichment of trace glycoproteins.

    Science.gov (United States)

    Li, Daojin; Li, Yang; Li, Xinglin; Bie, Zijun; Pan, Xianghua; Zhang, Qian; Liu, Zhen

    2015-03-06

    Boronate affinity materials, as effective sample enrichment sorbents for glycoproteomic analysis, have attracted increasing attention in recent years. However, most of boronate affinity materials suffer from an apparent limitation, limited binding strength. As a result, extraction of glycoproteins of trace concentration is rather difficult or impossible. In this study, we present a high boronate avidity monolithic capillary. Branched polyethyleneimine (PEI) was used as a scaffold to amplify the number of boronic acid moieties. While 2,4-difluoro-3-formyl-phenylboronic acid (DFFPBA), which exhibited ultrahigh affinity toward cis-diol-containing compounds, was employed as an affinity ligand. Due to the PEI-assisted synergistic multivalent binding, the monolithic column exhibited high boronate avidity toward glycoproteins, with binding constants of 10(-6)-10(-7)M. Such binding strength was the highest among already reported boronic acid-functionalized materials that can be used for glycoproteomic analysis. Besides, the boronate avidity monolithic column exhibited one additional beneficial feature, lowered binding pH (≥6.5). These features greatly favored the selective enrichment of trace glycoproteins from real samples. The feasibility for practical applications was demonstrated with the selective enrichment of trace glycoproteins in human saliva. As compared with other boronate avidity/affinity materials, the boronate avidity monolithic capillary exhibited the best performance. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. Separation and Analysis of Boron Isotope in High Plant by Thermal Ionization Mass Spectrometry

    OpenAIRE

    Xu, Qingcai; Dong, Yuliang; Zhu, Huayu; Sun, Aide

    2015-01-01

    Knowledge of boron and its isotope in plants is useful to better understand the transposition and translocation of boron within plant, the geochemical behavior in the interface between soil and plant, and the biogeochemical cycle of boron. It is critical to develop a useful method to separate boron from the plant for the geochemical application of boron and its isotope. A method was developed for the extraction of boron in plant sample, whose isotope was determined by thermal ionization mass ...

  14. Inverse-Frontal Chromatography studies on enrichment of Boron-10 using quaternery 4-vinylpyridine-divinylbenzene resin

    International Nuclear Information System (INIS)

    Bejawada, Venki; Mohapatra, C.; Rao, A.S.; Prasad, K.L.; Murthy, P.K.; Rao, A.K.; Singh, H.P.; Vithal, G.K.; Kumar, Sangita D.

    2014-01-01

    In order to enrich 10 B, band migration of boric acid-mannitol with hydrochloric acid solution was performed by inverse frontal chromatography on a porous, 25% crosslinked, 38% quaternized 4-vinylpyridine-divinylbenzene resin (py-resin). The work was initiated to replace the existing strong base anion exchange resin type-II (SBA-II) which is used in Boron Enrichment Plant (BEP) of heavy water plant Manuguru. Before its application in BEP, it is mandatory to evaluate py-resin for its performance. The studies showed that maximum of 40% 10 B enrichment observed after 13 m band movement and there was no further improvement, hence profile sampling carried out after 28 m. (author)

  15. Radiological analysis of plutonium glass batches with natural/enriched boron

    International Nuclear Information System (INIS)

    Rainisch, R.

    2000-01-01

    The disposition of surplus plutonium inventories by the US Department of Energy (DOE) includes the immobilization of certain plutonium materials in a borosilicate glass matrix, also referred to as vitrification. This paper addresses source terms of plutonium masses immobilized in a borosilicate glass matrix where the glass components include both natural boron and enriched boron. The calculated source terms pertain to neutron and gamma source strength (particles per second), and source spectrum changes. The calculated source terms corresponding to natural boron and enriched boron are compared to determine the benefits (decrease in radiation source terms) for to the use of enriched boron. The analysis of plutonium glass source terms shows that a large component of the neutron source terms is due to (a, n) reactions. The Americium-241 and plutonium present in the glass emit alpha particles (a). These alpha particles interact with low-Z nuclides like B-11, B-10, and O-17 in the glass to produce neutrons. The low-Z nuclides are referred to as target particles. The reference glass contains 9.4 wt percent B 2 O 3 . Boron-11 was found to strongly support the (a, n) reactions in the glass matrix. B-11 has a natural abundance of over 80 percent. The (a, n) reaction rates for B-10 are lower than for B-11 and the analysis shows that the plutonium glass neutron source terms can be reduced by artificially enriching natural boron with B-10. The natural abundance of B-10 is 19.9 percent. Boron enriched to 96-wt percent B-10 or above can be obtained commercially. Since lower source terms imply lower dose rates to radiation workers handling the plutonium glass materials, it is important to know the achievable decrease in source terms as a result of boron enrichment. Plutonium materials are normally handled in glove boxes with shielded glass windows and the work entails both extremity and whole-body exposures. Lowering the source terms of the plutonium batches will make the handling

  16. DOE enrichment plants-safeguards means business

    International Nuclear Information System (INIS)

    Donnelly, R.

    1987-01-01

    The Portsmouth Gaseous Diffusion Plant, owned by the US Department of Energy (DOE) and operated by Martin Marietta Energy Systems, Inc., is a full service enrichment plant. Its long enriching cascade can process uranium hexafluoride (UF 6 ) feeds at almost any 235 U level and can produce UF 6 over the complete spectrum from depleted to very highly enriched uranium. The DOE uranium enrichment program is a government-owned enterprise operating as a business. The operating concerns of the DOE uranium enrichment plants and their safeguards programs have evolved together over the past three decades, and that evolution will likely continue. As the risk associated with possession, processing, and shipment of strategic nuclear material increased, the protection and control of it increased; as the value of the product grew with time, better ways were found to measure and conserve it. In each of these areas, safeguards objectives and the business requirements of the plant are complementary, and the progress made in one area has been reflected by progress in the other. The plant's material control and accountability program has become crucial to such business requirements as quantifying the enriched uranium (separative work units) produced in each monthly period and convincing financial auditors that the multibillion dollar enriched uranium assets located at the Portsmouth plant are properly stated

  17. Radiation shielding properties of high performance concrete reinforced with basalt fibers infused with natural and enriched boron

    Energy Technology Data Exchange (ETDEWEB)

    Zorla, Eyüp; Ipbüker, Cagatay [University of Tartu, Institute of Physics (Estonia); Biland, Alex [US Basalt Corp., Houston (United States); Kiisk, Madis [University of Tartu, Institute of Physics (Estonia); Kovaljov, Sergei [OÜ Basaltest, Tartu (Estonia); Tkaczyk, Alan H. [University of Tartu, Institute of Physics (Estonia); Gulik, Volodymyr, E-mail: volodymyr.gulik@gmail.com [Institute for Safety Problems of Nuclear Power Plants, Lysogirska 12, of. 201, 03028 Kyiv (Ukraine)

    2017-03-15

    Highlights: • Basalt fiber infused with natural and enriched boron in varying proportions. • Gamma-ray attenuation remains stable with addition of basalt-boron fiber. • Improvement in neutron shielding for nuclear facilities producing fast fission spectrum. • Basalt-boron fiber could decrease the shielding thickness in thermal spectrum reactors. - Abstract: The importance of radiation shielding is increasing in parallel with the expansion of the application areas of nuclear technologies. This study investigates the radiation shielding properties of two types of high strength concrete reinforced with basalt fibers infused with 12–20% boron oxide, containing varying fractions of natural and enriched boron. The gamma-ray shielding characteristics are analyzed with the help of the WinXCom, whereas the neutron shielding characteristics are modeled and computed by Monte Carlo Serpent code. For gamma-ray shielding, the attenuation coefficients of the studied samples do not display any significant variation due to the addition of basalt-boron fibers at any mixing proportion. For neutron shielding, the addition of basalt-boron fiber has negligible effects in the case of very fast neutrons (14 MeV), but it could considerably improve the neutron shielding of concrete for nuclear facilities producing a fast fission spectrum (e.g. with reactors as BN-800, FBTR) and thermal neutron spectrum (Light Water Reactors (LWR)). It was also found that basalt-boron fiber could decrease the thickness of radiation shielding material in thermal spectrum reactors.

  18. Use of inductively coupled plasma-mass spectrometry in boron-10 stable isotope experiments with plants, rats, and humans.

    Science.gov (United States)

    Vanderpool, R A; Hoff, D; Johnson, P E

    1994-11-01

    The commercial availability of inductively coupled plasma-mass spectrometry technology (ICP-MS) has presented the opportunity to measure the boron concentrations and isotope ratios in a large number of samples with minimal sample preparation. A typical analytical sequence for fecal samples consists of 25 acid blanks, 1 digestion blank, 5 calibration solutions, 4 standard reference material solutions, 10 samples, and 4 natural abundance bias standards. Boron detection limits (3 x 1 sigma) for acid blanks are 0.11 ppb for 10B, and 0.40 ppb for 11B. Isotope ratios were measured in fecal samples with 20 to 50 ppb boron with sample had a 1.0 ppb boron memory after a 6-min washout. Boron isotope ratios in geological materials are highly variable; apparently this variability is reflected in plants of a fixed natural abundance value for boron requires that a natural abundance ratio be determined for each sample or related data set. The natural abundance variability also prevents quantitation and calculation of isotope dilution by instrument-supplied software. To measure boron transport in animal systems, 20 micrograms of 10B were fed to a fasted rat. During the 3 days after a 10B oral dose, 95% of the 10B was recovered from the urine and 4% from the feces. Urinary isotope ratios, 11B/10B, changed from a natural abundance of 4.1140 to an enriched value of 0.95077, a 77% change.(ABSTRACT TRUNCATED AT 250 WORDS)

  19. Unattended safeguards instrumentation at centrifuge enrichment plants

    International Nuclear Information System (INIS)

    Smith, L. Eric; Lebrun, Alain R.; Labella, Rocco

    2014-01-01

    As global uranium enrichment capacity under international safeguards expands, the International Atomic Energy Agency (IAEA) is challenged to develop effective safeguards approaches at gaseous centrifuge enrichment plants, particularly high‑capacity plants, while working within budgetary constraints. New safeguards approaches should meet the high‑level verification objectives for such facilities (i.e., timely detection of: diversion of declared material, excess production beyond declared amounts, and production of enrichment levels higher than declared), but should also strive for efficiency advantages in implementation, for both the IAEA and operators. Under the Agency’s State- level approach to safeguards implementation, the Agency needs a flexible toolbox of technologies, allowing tailoring of safeguards measures for each individual enrichment facility. In this paper, the potential roles and development status for three different types of unattended measurement instrumentation are discussed. On‑Line Enrichment Monitors (OLEM) could provide continuous enrichment measurement for 100% of the declared gas flowing through unit header pipes. Unattended Cylinder Verification Stations (UCVS) could provide unattended verification of the declared uranium mass and enrichment of 100% of the cylinders moving through the plant, but also apply and verify an ‘NDA Fingerprint’ to preserve verification knowledge on the contents of each cylinder throughout its life in the facility. Sharing of the operator’s load cell signals from feed and withdrawal stations could count all cylinders introduced to the process and provide periodic monitoring of the uranium mass balance for in‑process material. The integration of load cell, OLEM and UCVS data streams offers the possibility for 100% verification of declared cylinder flow, and enables the periodic verification of the declared 235 U mass balance in the plant. These new capabilities would enhance the IAEA

  20. Integrated design of SIGMA uranium enrichment plants

    International Nuclear Information System (INIS)

    Rivarola, Martin E.; Brasnarof, Daniel O.

    1999-01-01

    In the present work, we describe a preliminary analysis of the design feedbacks in a Uranium Enrichment Plant, using the SIGMA concept. Starting from the result of this analysis, a computer code has been generated, which allows finding the optimal configurations of plants, for a fixed production rate. The computer code developed includes the model of the Thermohydraulic loop of a SIGMA module. The model contains numerical calculations of the main components of the circuit. During the calculations, the main components are dimensioned, for a posterior cost compute. The program also makes an estimation of the enrichment gain of the porous membrane, for each separation stage. Once the dimensions of the main components are known, using the enrichment cascade calculation, the capital and operation costs of the plant could be determined. At this point it is simple to calculate a leveled cost of the Separative Work Unit (SWU). A numerical optimizer is also included in the program. This optimizer finds the optimal cascade configuration, for a given set of design parameters. The whole-integrated program permits to investigate in detail the feedback in the component design. Therefore, the sensibility of the more relevant parameters can be computed, with respect of the economical variables of the plant. (author)

  1. Development and validation of a method to determine the boron isotopic composition of crop plants.

    Science.gov (United States)

    Rosner, Martin; Pritzkow, Wolfgang; Vogl, Jochen; Voerkelius, Susanne

    2011-04-01

    We present a comprehensive chemical and mass spectrometric method to determine boron isotopic compositions of plant tissue. The method including dry ashing, a three-step ion chromatographic boron-matrix separation, and (11)B/(10)B isotope ratio determinations using the Cs(2)BO(2)(+) graphite technique has been validated using certified reference and quality control materials. The developed method is capable to determine δ(11)B values in plant tissue down to boron concentrations of 1 mg/kg with an expanded uncertainty of ≤1.7‰ (k = 2). The determined δ(11)B values reveal an enormous isotopic range of boron in plant tissues covering three-quarters of the natural terrestrial occurring variation in the boron isotopic composition. As the local environment and anthropogenic activity mainly control the boron intake of plants, the boron isotopic composition of plants can be used for food provenance studies.

  2. Separation and Analysis of Boron Isotope in High Plant by Thermal Ionization Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Qingcai Xu

    2015-01-01

    Full Text Available Knowledge of boron and its isotope in plants is useful to better understand the transposition and translocation of boron within plant, the geochemical behavior in the interface between soil and plant, and the biogeochemical cycle of boron. It is critical to develop a useful method to separate boron from the plant for the geochemical application of boron and its isotope. A method was developed for the extraction of boron in plant sample, whose isotope was determined by thermal ionization mass spectrometry. The results indicated that this method of dry ashing coupled with two-step ion-exchange chromatography is powerful for the separation of boron in plant sample with large amounts of organic matters completely. The ratios of boron isotope composition in those plant tissue samples ranged from -19.45‰ to +28.13‰ (total range: 47.58‰ with a mean value of 2.61±11.76‰ SD. The stem and root isotopic compositions were lower than those in flower and leaf. The molecular mechanism of boron isotope may be responsible for the observed variation of boron isotopic composition and are considered as a useful tool for the better understanding of boron cycling process in the environment and for the signature of living systems.

  3. Separation and Analysis of Boron Isotope in High Plant by Thermal Ionization Mass Spectrometry.

    Science.gov (United States)

    Xu, Qingcai; Dong, Yuliang; Zhu, Huayu; Sun, Aide

    2015-01-01

    Knowledge of boron and its isotope in plants is useful to better understand the transposition and translocation of boron within plant, the geochemical behavior in the interface between soil and plant, and the biogeochemical cycle of boron. It is critical to develop a useful method to separate boron from the plant for the geochemical application of boron and its isotope. A method was developed for the extraction of boron in plant sample, whose isotope was determined by thermal ionization mass spectrometry. The results indicated that this method of dry ashing coupled with two-step ion-exchange chromatography is powerful for the separation of boron in plant sample with large amounts of organic matters completely. The ratios of boron isotope composition in those plant tissue samples ranged from -19.45‰ to +28.13‰ (total range: 47.58‰) with a mean value of 2.61 ± 11.76‰ SD. The stem and root isotopic compositions were lower than those in flower and leaf. The molecular mechanism of boron isotope may be responsible for the observed variation of boron isotopic composition and are considered as a useful tool for the better understanding of boron cycling process in the environment and for the signature of living systems.

  4. Economic evaluation of laser enrichment plant

    International Nuclear Information System (INIS)

    Arisawa, Takashi; Shiba, Koreyuki

    1983-08-01

    Operational characteristics of Laser Enrichment Plant are described based on the data available at present. And its economy is also discussed from the view point of investment and energy consumption. In the procedure of this estimation, the composition of the plant is firstly considered, secondly each component is designed, and thirdly the production cost of each component is estimated. Then the sensitivity of the component cost on the plant cost is analysed, which leads to the optimization of the product cost and the determination of the economic plant size, etc. The results shows that the power cost of the electric gun occupies the large majority of the total power cost, and that the capital cost of laser devices occupies most of the total capital cost. (author)

  5. Gas-phase UF6 enrichment monitor for enrichment plant safeguards

    International Nuclear Information System (INIS)

    Strittmatter, R.B.; Tape, J.W.

    1980-03-01

    An in-line enrichment monitor is being developed to provide real-time enrichment data for the gas-phase UF 6 feed stream of an enrichment plant. The nondestructive gamma-ray assay method can be used to determine the enrichment of natural UF 6 with a relative precision of better than 1% for a wide range of pressures

  6. Use of inductively coupled plasma-mass spectrometry in boron-10 stable isotope experiments with plants, rats, and humans.

    Science.gov (United States)

    Vanderpool, R A; Hoff, D; Johnson, P E

    1994-01-01

    The commercial availability of inductively coupled plasma-mass spectrometry technology (ICP-MS) has presented the opportunity to measure the boron concentrations and isotope ratios in a large number of samples with minimal sample preparation. A typical analytical sequence for fecal samples consists of 25 acid blanks, 1 digestion blank, 5 calibration solutions, 4 standard reference material solutions, 10 samples, and 4 natural abundance bias standards. Boron detection limits (3 x 1 sigma) for acid blanks are 0.11 ppb for 10B, and 0.40 ppb for 11B. Isotope ratios were measured in fecal samples with 20 to 50 ppb boron with boron biological sample had a 1.0 ppb boron memory after a 6-min washout. Boron isotope ratios in geological materials are highly variable; apparently this variability is reflected in plants of a fixed natural abundance value for boron requires that a natural abundance ratio be determined for each sample or related data set. The natural abundance variability also prevents quantitation and calculation of isotope dilution by instrument-supplied software. To measure boron transport in animal systems, 20 micrograms of 10B were fed to a fasted rat. During the 3 days after a 10B oral dose, 95% of the 10B was recovered from the urine and 4% from the feces. Urinary isotope ratios, 11B/10B, changed from a natural abundance of 4.1140 to an enriched value of 0.95077, a 77% change.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7889873

  7. Criticality analysis in uranium enrichment plant

    International Nuclear Information System (INIS)

    Okamoto, Tsuyoshi; Kiyose, Ryohei

    1977-01-01

    In a large scale uranium enrichment plant, uranium inventory in cascade rooms is not very large in quantity, but the facilities dealing with the largest quantity of uranium in that process are the UF 6 gas supply system and the blending system for controlling the product concentration. When UF 6 spills out of these systems, the enriched uranium is accumulated, and the danger of criticality accident is feared. If a NaF trap is placed at the forestage of waste gas treatment system, plenty of UF 6 and HF are adsorbed together in the NaF trap. Thus, here is the necessity of checking the safety against criticality. Various assumptions were made to perform the computation surveying the criticality of the system composed of UF 6 and HF adsorbed on NaF traps with WIMS code (transport analysis). The minimum critical radius resulted in about 53 cm in case of 3.5% enriched fuel for light water reactors. The optimum volume ratio of fissile material in the double salt UF 6 .2NaF and NaF.HF is about 40 vol. %. While, criticality survey computation was also made for the annular NaF trap having the central cooling tube, and it was found that the effect of cooling tube radius did not decrease the multiplication factor up to the cooling tube radius of about 5 cm. (Wakatsuki, Y.)

  8. Alleviation of Boron Stress through Plant Derived Smoke Extracts in Sorghum bicolor

    Directory of Open Access Journals (Sweden)

    Pirzada Khan

    2014-08-01

    Full Text Available Boron is an essential micronutrient necessary for plant growth at optimum concentration. However, at high concentrations boron affects plant growth and is toxic to cells. Aqueous extract of plant-derived smoke has been used as a growth regulator for the last two decades to improve seed germination and seedling vigor. It has been established that plant-derived smoke possesses some compounds that act like plant growth hormones. The present research was the first comprehensive attempt to investigate the alleviation of boron stress with plant-derived smoke aqueous extract on Sorghum (Sorghum bicolor seed. Smoke extracts of five plants, i.e. Cymbopogon jwarancusa, Eucalyptus camaldulensis, Peganum harmala, Datura alba and Melia azedarach each with six dilutions (Concentrated, 1:100, 1:200, 1:300, 1:400 and 1:500 were used. While boron solutions at concentrations of 5, 10, 15, 20 and 25 ppm were used for stress. Among the dilutions of smoke, 1:500 of E. camaldulensis significantly increased germination percentage, root and shoot length, number of secondary roots and fresh weight of root and shoot while, boron stress reduced growth of Sorghum. It was observed that combined effect of boron solution and E. camaldulensis smoke extract overcome inhibition and significantly improved plant growth. Present research work investigated that the smoke solution has the potential to alleviate boron toxicity by reducing the uptake of boron by maintaining integrity of plant cell wall. The present investigation suggested that plant derived smoke has the potential to alleviate boron stress and can be used to overcome yield losses caused by boron stress to plants.

  9. Numerical Boron mixing studies for Loviisa Nuclear Power Plant

    Energy Technology Data Exchange (ETDEWEB)

    Gango, P. [IVO International Ltd. (Finland)

    1995-09-01

    A program has been started for studying numerically boron mixing in the downcomer of Loviisa NPP (VVER-440). Mixing during the transport of a diluted slug from the loop to the core might serve as an inherent protection mechanism against severe reactivity accidents in inhomogenous boron dilution scenarios for PWRs. The commercial general purpose Computational Fluid Dynamics (CFD) core PHOENICS is used for solving the governing fluid flow equations in the downcomer geometry of VVER-440. So far numerical analyses have been performed for steady state operation conditions and two different pump driven transients. The steady state analyses focused on model development and validation against existing experimental data. The two pump driven transient scenarios reported are based on slug transport during the start of the sixth and first loop respectively. The results from the two transients show that mixing is case and plant specific; the high and open downcomer geometry of VVER-440 seems to be advantageous from mixing point of view. In addition the analyzing work for the {open_quotes}first pump start{close_quotes} scenario brought up some considerations about flow distribution in the existing experimental facilities.

  10. Evaluation of economical at a uranium enrichment demonstration plant

    International Nuclear Information System (INIS)

    Sugitsue, Noritake

    2001-01-01

    In this report, the economy of technical achievement apply in the uranium enrichment demonstration plant is evaluated. From the evaluation, it can be concluded that the expected purpose was achieved because there was a definite economic prospect to commercial plant. The benefit analysis of thirteen years operation of the uranium enrichment demonstration plant also provides a financial aspect of the uranium enrichment business. Therefore, the performance, price and reliability of the centrifuge is an important factor in the uranium enrichment business. And the continuous development of a centrifuge while considering balance with the development cost is necessary for the business in the future. (author)

  11. Extractability, plant yield and toxicity thresholds for boron in compost

    Energy Technology Data Exchange (ETDEWEB)

    Brinton, W.F.; Evans, E.; Blewett, C. [Woods End Labs Inc., Mt. Vernon, ME (United States)

    2008-04-01

    Boron (B) is a trace element essential to crop growth in small soil concentrations (0.2-1.5ppm), yet may produce plant toxicity symptoms readily as the amount in the soil solution increases over 2ppm. Our study examined commercial compost made with coal fly-ash used to prepare growing media for cultivars of varying sensitivity (corn, beans, cucumber, peas). We examined total vs. extractable boron content and relate final visual symptoms of B-toxicity to yields and tissue concentrations. Visual toxicity effects included tip burn (corn), leaf mottling and necrosis (beans and peas) and leaf mottling and cupping (cucumbers). Fly ash added to compost increased hot-water soluble (HWS) B in proportion to rate and in dependence on pH, with 30% and 10% of total-B expressed as HWS-B at a media pH of 6 and 7.5, respectively. Biomass for bean and cucumber was significantly reduced by 45 to 55%, respectively, by addition of 33% fly-ash compost to growing media (28ppm total-B) while plant tissue-B increased by 6- to 4-fold, respectively. Economic yield depressions in compost media are evident for all crops and appeared at levels of HWS-B in compost media exceeding 5 ppm. The study underscores the need for careful management of exogenous factors that may be present in composts and suggests detailed understanding of media-pH and cultivar preferences may be required in preparation of growing media in order to reduce potential negative growth effects.

  12. Neutron-induced autoradiography for determining the boron distribution in plant organs

    International Nuclear Information System (INIS)

    Kluge, R.; Podlesak, W.

    1982-01-01

    As could be shown in preliminary tests with potato leaves, the distribution of boron in plant organs can be displayed qualitatively and determined quantitatively by neutron-induced autoradiography using dielectric track detectors. The detection limit is some ppm B in absolutely dry plant tissue. Semiquantitative interpretation of the autoradiograms by classing track densities with the aid of the image processing instrument 'Densitron' offers favourable possibilities for survey analyses. In this way boron concentration ranges can be determined with the aid of standards and a justifiable effort, so that a sufficiently precise assessment of the boron distribution in plant organs becomes possible. (author)

  13. Differentiation analysis of boron isotopic fractionation in different forms within plant organ samples.

    Science.gov (United States)

    Sun, Aide; Xu, Qingcai; Wei, Gangjian; Zhu, Huayu; Chen, Xuefei

    2018-03-01

    As a critical micronutrient, boron (B) plays an important role in plant growth and embryonic development. To further understand the effects of B uptake, transportation and isotopic fractionation, the contents and isotopic compositions of hydro-soluble B in the sap and structural B fixed in the cell within individual plant tissues were investigated. The B isotope ratio was determined by multi-collector inductively coupled plasma mass spectrometry. The δ 11 B values in hydro-soluble and structural B in the investigated plant samples ranged from -1.57‰ to +11.30‰ and from +6.57‰ to +16.64‰, respectively. Different fractionation factors of the B isotopes, in the range of 0.9954-1.0150, were observed in these samples, indicating that in most plant tissues, the heavy isotope ( 11 B) was preferentially enriched in structural B, which was fixed into the cell. However, there was a reversal in the fractionation of B isotopic compositions in the fruit samples compared with the other plant tissue samples. It is more powerful to examine the molecular mechanisms of B transport, uptake and utilization than the use of limited plant organ samples containing a mixture of hydro-soluble and structural B within different intra-plant compartments and in inter-plant interactions. These isotopic shifts, which may be used as important isotopic indicators, contribute to the surface processes interactions in the plant-soil system and the knowledge of the molecular mechanisms of B in the uptake and absorption by different plant species in nature. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Structure and superconductivity of isotope-enriched boron-doped diamond.

    Science.gov (United States)

    Ekimov, Evgeny A; Sidorov, Vladimir A; Zoteev, Andrey V; Lebed, Julia B; Thompson, Joe D; Stishov, Sergey M

    2008-12-01

    Superconducting boron-doped diamond samples were synthesized with isotopes of 10 B, 11 B, 13 C and 12 C. We claim the presence of a carbon isotope effect on the superconducting transition temperature, which supports the 'diamond-carbon'-related nature of superconductivity and the importance of the electron-phonon interaction as the mechanism of superconductivity in diamond. Isotope substitution permits us to relate almost all bands in the Raman spectra of heavily boron-doped diamond to the vibrations of carbon atoms. The 500 cm -1 Raman band shifts with either carbon or boron isotope substitution and may be associated with vibrations of paired or clustered boron. The absence of a superconducting transition (down to 1.6 K) in diamonds synthesized in the Co-C-B system at 1900 K correlates with the small boron concentration deduced from lattice parameters.

  15. Development of particle induced gamma-ray emission methods for nondestructive determination of isotopic composition of boron and its total concentration in natural and enriched samples.

    Science.gov (United States)

    Chhillar, Sumit; Acharya, Raghunath; Sodaye, Suparna; Pujari, Pradeep K

    2014-11-18

    We report simple particle induced gamma-ray emission (PIGE) methods using a 4 MeV proton beam for simultaneous and nondestructive determination of the isotopic composition of boron ((10)B/(11)B atom ratio) and total boron concentrations in various solid samples with natural isotopic composition and enriched with (10)B. It involves measurement of prompt gamma-rays at 429, 718, and 2125 keV from (10)B(p,αγ)(7)Be, (10)B(p, p'γ)(10)B, and (11)B(p, p'γ)(11)B reactions, respectively. The isotopic composition of boron in natural and enriched samples was determined by comparing peak area ratios corresponding to (10)B and (11)B of samples to natural boric acid standard. An in situ current normalized PIGE method, using F or Al, was standardized for total B concentration determination. The methods were validated by analyzing stoichiometric boron compounds and applied to samples such as boron carbide, boric acid, carborane, and borosilicate glass. Isotopic compositions of boron in the range of 0.247-2.0 corresponding to (10)B in the range of 19.8-67.0 atom % and total B concentrations in the range of 5-78 wt % were determined. It has been demonstrated that PIGE offers a simple and alternate method for total boron as well as isotopic composition determination in boron based solid samples, including neutron absorbers that are important in nuclear technology.

  16. A hybrid monolithic column based on boronate-functionalized graphene oxide nanosheets for online specific enrichment of glycoproteins.

    Science.gov (United States)

    Zhou, Chanyuan; Chen, Xiaoman; Du, Zhuo; Li, Gongke; Xiao, Xiaohua; Cai, Zongwei

    2017-05-19

    A hybrid monolithic column based on aminophenylboronic acid (APBA)-functionalized graphene oxide (GO) has been developed and used for selective enrichment of glycoproteins. The APBA/GO composites were homogeneously incorporated into a polymer monolithic column with the help of oligomer matrix and followed by in situ polymerization. The effect of dispersion of APBA/GO composites in the polymerization mixture on the performance of the monolithic column was explored in detail. The presence of graphene oxide not only enlarged the BET surface area from 6.3m 2 /g to 169.4m 2 /g, but also provided abundant boronic acid moieties for glycoprotein extraction, which improved the enrichment selectivity and efficiency for glycoproteins. The APBA/GO hybrid monolithic column was incorporated into a sequential injection system, which facilitated online extraction of proteins. Combining the superior properties of extraordinary surface area of GO and the affinity interaction of APBA to glycoproteins, the APBA/GO hybrid monolithic column showed higher enrichment factors for glycoproteins than other proteins without cis-diol-containing groups. Also, under comparable or even shorter processing time and without the addition of any organic solvent, it showed higher binding capacity toward glycoproteins compared with the conventional boronate affinity monolithic column. The practical applicability of this system was demonstrated by processing of egg white samples for extraction of ovalbumin and ovotransferrin, and satisfactory results were obtained by assay with SDS-PAGE. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Structure and superconductivity of isotope-enriched boron-doped diamond

    OpenAIRE

    Evgeny A Ekimov, Vladimir A Sidorov, Andrey V Zoteev, Yury B Lebed, Joe D Thompson and Sergey M Stishov

    2008-01-01

    Superconducting boron-doped diamond samples were synthesized with isotopes of 10B, 11B, 13C and 12C. We claim the presence of a carbon isotope effect on the superconducting transition temperature, which supports the ‘diamond-carbon’-related nature of superconductivity and the importance of the electron–phonon interaction as the mechanism of superconductivity in diamond. Isotope substitution permits us to relate almost all bands in the Raman spectra of heavily boron-doped diamond to the vibrat...

  18. Genetic engineering of syringyl-enriched lignin in plants

    Science.gov (United States)

    Chiang, Vincent Lee; Li, Laigeng

    2004-11-02

    The present invention relates to a novel DNA sequence, which encodes a previously unidentified lignin biosynthetic pathway enzyme, sinapyl alcohol dehydrogenase (SAD) that regulates the biosynthesis of syringyl lignin in plants. Also provided are methods for incorporating this novel SAD gene sequence or substantially similar sequences into a plant genome for genetic engineering of syringyl-enriched lignin in plants.

  19. Boron-Mediated Plant Somatic Embryogenesis: A Provocative Model

    Directory of Open Access Journals (Sweden)

    Dhananjay K. Pandey

    2012-01-01

    Full Text Available A central question in plant regeneration biology concerns the primary driving forces invoking the acquisition of somatic embryogenesis. Recently, the role of micronutrient boron (B in the initiation and perpetuation of embryogenesis has drawn considerable attention within the scientific community. This interest may be due in part to the bewildering observation that the system-wide induction of embryogenic potential significantly varied in response to a minimal to optimal supply of B (minimal ≤ 0.1 mM, optimal = 0.1 mM. At the cellular level, certain channel proteins and cell wall-related proteins important for the induction of embryogenesis have been shown to be transcriptionally upregulated in response to minimal B supply suggesting the vital role of B in the induction of embryogenesis. At the molecular level, minimal to no B supply increased the endogenous level of auxin, which subsequently influenced the auxin-inducible somatic embryogenesis receptor kinases, suggesting the role of B in the induction of embryogenesis. Also, minimal B concentration may “turn on” other genetic and/or cellular transfactors reported earlier to be essential for cell-restructuring and induction of embryogenesis. In this paper, both the direct and indirect roles of B in the induction of somatic embryogenesis are highlighted and suggested for future validation.

  20. Boron deficiency in woody plants: various responses and tolerance mechanisms

    Directory of Open Access Journals (Sweden)

    Nannan eWang

    2015-10-01

    Full Text Available Boron (B is an essential microelement for higher plants, and its deficiency is widespread around the world and constrains the productivity of both agriculture and forestry. In the last decades, accumulating studies on model or herbaceous plants have contributed greatly to our understanding of the complex network of B-deficiency responses and mechanisms for tolerance. In woody plants, however, only a few studies have been conducted and they are not well synthesised. Trees have a larger body size, longer lifespan and more B reserves than do herbaceous plants, indicating that woody species might undergo long-term or mild B deficiency more commonly and that a more complicated B reserves must accordingly be developed to cope with B deficiency. In addition, the highly heterozygous genetic background of tree species suggests that they may have a more complicated mechanism of response and tolerance to B deficiency than do model plants.B-deficient trees usually exhibit two key visible symptoms: depression of growing points (root tip, bud, flower, and young leaf and deformity of organs (root, shoot, leaf, and fruit. These symptoms may be ascribed to B functioning in the cell wall and membrane, and B deficiency results in damage to vascular tissues and the suppression of both B and water transport. B deficiency also affects metabolic processes, such as increased lignin and phenol, and decreased leaf photosynthesis. These negative effects will influence the quality and quantity of wood, fruit and other agricultural products.B efficiency probably originates from a combined effect of three processes: B uptake, B translocation and retranslocation, and B utilization. Root morphology and mycorrhiza can affect the B uptake efficiency of trees. During B translocation from the root to shoot, differences in B concentration between root cell saps and xylem exudates, as well as water use efficiency, may play key roles in tolerance to B deficiency. In addition, B

  1. Enriched Boron-Doped Amorphous Selenium Based Position-Sensitive Solid-State Thermal Neutron Detector for MPACT Applications

    Energy Technology Data Exchange (ETDEWEB)

    Mandal, Krishna [Univ. of South Carolina, Columbia, SC (United States)

    2017-09-29

    High-efficiency thermal neutron detectors with compact size, low power-rating and high spatial, temporal and energy resolution are essential to execute non-proliferation and safeguard protocols. The demands of such detector are not fully covered by the current detection system such as gas proportional counters or scintillator-photomultiplier tube combinations, which are limited by their detection efficiency, stability of response, speed of operation, and physical size. Furthermore, world-wide shortage of 3He gas, required for widely used gas detection method, has further prompted to design an alternative system. Therefore, a solid-state neutron detection system without the requirement of 3He will be very desirable. To address the above technology gap, we had proposed to develop new room temperature solidstate thermal neutron detectors based on enriched boron (10B) and enriched lithium (6Li) doped amorphous Se (As- 0.52%, Cl 5 ppm) semiconductor for MPACT applications. The proposed alloy materials have been identified for its many favorable characteristics - a wide bandgap (~2.2 eV at 300 K) for room temperature operation, high glass transition temperature (tg ~ 85°C), a high thermal neutron cross-section (for boron ~ 3840 barns, for lithium ~ 940 barns, 1 barn = 10-24 cm2), low effective atomic number of Se for small gamma ray sensitivity, and high radiation tolerance due to its amorphous structure.

  2. BAD-lectins: boronic acid-decorated lectins with enhanced binding affinity for the selective enrichment of glycoproteins.

    Science.gov (United States)

    Lu, Ying-Wei; Chien, Chih-Wei; Lin, Po-Chiao; Huang, Li-De; Chen, Chang-Yang; Wu, Sz-Wei; Han, Chia-Li; Khoo, Kay-Hooi; Lin, Chun-Cheng; Chen, Yu-Ju

    2013-09-03

    The weak and variable binding affinities exhibited by lectin-carbohydrate interactions have often compromised the practical utility of lectin in capturing glycoproteins for glycoproteomic applications. We report here the development and applications of a new type of hybrid biomaterial, namely a boronic acid-decorated lectin (BAD-lectin), for efficient bifunctional glycoprotein labeling and enrichment. Our binding studies showed an enhanced affinity by BAD-lectin, likely to be mediated via the formation of boronate ester linkages between the lectin and glycan subsequent to the initial recognition process and thus preserving its glycan-specificity. Moreover, when attached to magnetic nanoparticles (BAD-lectin@MNPs), 2 to 60-fold improvement on detection sensitivity and enrichment efficiency for specific glycoproteins was observed over the independent use of either lectin or BA. Tested at the level of whole cell lysates for glycoproteomic applications, three different types of BAD-lectin@MNPs exhibited excellent specificities with only 6% overlapping among the 295 N-linked glycopeptides identified. As many as 236 N-linked glycopeptides (80%) were uniquely identified by one of the BAD-lectin@MNPs. These results indicated that the enhanced glycan-selective recognition and binding affinity of BAD-lectin@MNPs will facilitate a complementary identification of the under-explored glycoproteome.

  3. Improved verification methods for safeguards verifications at enrichment plants

    International Nuclear Information System (INIS)

    Lebrun, A.; Kane, S. C.; Bourva, L.; Poirier, S.; Loghin, N. E.; Langlands, D.

    2009-01-01

    The International Atomic Energy Agency (IAEA) has initiated a coordinated research and development programme to improve its verification methods and equipment applicable to enrichment plants. The programme entails several individual projects to meet the objectives of the IAEA Safeguards Model Approach for Gas Centrifuge Enrichment Plants updated in 2006. Upgrades of verification methods to confirm the absence of HEU (highly enriched uranium) production have been initiated and, in particular, the Cascade Header Enrichment Monitor (CHEM) has been redesigned to reduce its weight and incorporate an electrically cooled germanium detector. Such detectors are also introduced to improve the attended verification of UF 6 cylinders for the verification of the material balance. Data sharing of authenticated operator weighing systems such as accountancy scales and process load cells is also investigated as a cost efficient and an effective safeguards measure combined with unannounced inspections, surveillance and non-destructive assay (NDA) measurement. (authors)

  4. Nuclear material safeguards for enrichments plants: Part 4, Gas Centrifuge Enrichment Plant: Diversion scenarios and IAEA safeguards activities: Safeguards training course

    Energy Technology Data Exchange (ETDEWEB)

    1988-10-01

    This publication is Part 4 of a safeguards training course in Nuclear Material Safeguards for enrichment plants. This part of the course deals with diversion scenarios and safeguards activities at gas centrifuge enrichment plants.

  5. Measurement of the enrichment of uranium in the pipework of a gas centrifuge enrichment plant

    International Nuclear Information System (INIS)

    Packer, T.W.; Lees, E.W.; Close, D.; Nixon, K.V.; Pratt, J.C.; Strittmatter, R.

    1985-01-01

    The US and UK have been separately working on the development of a NDA instrument to determine the enrichment of gaseous UF 6 at low pressures in cascade header pipework in line with the conclusions of the Hexapartite Safeguards Project viz. the instrument is capable of making a ''go/no go'' decision of whether the enrichment is less than/greater than 20%. Recently, there has been a series of very useful technical exchanges of ideas and information between the two countries. This has led to a technical formulation for such an instrumentation based on γ-ray spectrometry which, although plant-specific in certain features, nevertheless is based on the same physical principles. Experimental results from commercially operating enrichment plants are very encouraging and indicate that a complete measurement including set up time on the pipe should be attainable in about 30 minutes when measuring pipes of diameter around 110 mm. 5 refs., 4 figs

  6. Boron reclamation

    International Nuclear Information System (INIS)

    Smith, R.M.

    1980-07-01

    A process to recover high purity 10 B enriched crystalline boron powder from a polymeric matrix was developed on a laboratory basis and ultimately scaled up to production capacity. The process is based on controlled pyrolysis of boron-filled scrap followed by an acid leach and dry sieving operation to return the powder to the required purity and particle size specifications. Typically, the recovery rate of the crystalline powder is in excess of 98.5 percent, and some of the remaining boron is recovered in the form of boric acid. The minimum purity requirement of the recovered product is 98.6 percent total boron

  7. Antioxidant responses of lentil and barley plants to boron toxicity ...

    African Journals Online (AJOL)

    Administrator

    2Muammer Tepe; High Biochemist, Celal Bayar University Science and Arts Faculty, Turkey. Accepted 2 June, 2011. In this study, the effects of different nitrogen ... for 7-day growth cycle under the conditions of boron stress via different nitrogen sources (10 mM nitrogen in NH4 Cl, KNO3 and urea). As a result of the changes ...

  8. Centrifuge enrichment plants. (Latest citations from the NTIS bibliographic database). Published Search

    International Nuclear Information System (INIS)

    1993-09-01

    The bibliography contains citations concerning the design, control, monitoring, and safety of centrifuge enrichment plants. Power supplies, enrichment plant safeguards, facility design, cascade heater test loops to monitor the enrichment process, inspection strategies, and the socioeconomic effects of centrifuge enrichment plants are examined. Radioactive waste disposal problems are considered. (Contains a minimum of 171 citations and includes a subject term index and title list.)

  9. Nuclear material safeguards for enrichment plants: Part 4, Gas Centrifuge Enrichment Plant: Diversion scenarios and IAEA safeguards activities: Safeguards training course

    International Nuclear Information System (INIS)

    1987-10-01

    This 5-day training course on nuclear material safeguards for uranium enrichment plants has been developed to train IAEA professionals who are responsible for safeguarding uranium enrichment facilties on the safeguards relevant principles of enrichment technology, particularly as related to centrifuge enrichment plants. This volume contains discussions of diversions of declared material at a centrifuge plant, centrifuge facility material balance verification activities, enriching beyond declared levels in a centrifuge facility, safeguards inspection techniques that may be used inside cascade areas, and demonstration of the enrichment verification measurement technique for cascade header pipes

  10. Quality of deli-style turkey enriched with plant sterols.

    Science.gov (United States)

    Grasso, S; Brunton, N P; Lyng, J G; Harrison, S M; Monahan, F J

    2016-12-01

    Low-fat meat products could be excellent carriers for plant sterols, known for their cholesterol-lowering properties. In this study, we developed a protocol for the manufacture of a deli-style turkey enriched with plant sterols (S) at a level sufficient to deliver the maximum plant sterols amount recommended for cholesterol reduction by the European Food Safety Authority (3 g of plant sterols per day) in a 70 g portion. We investigated the stability of the plant sterols and the effects of their addition on the product quality. Plant sterols remained stable during the seven-day storage period. The addition of plant sterols significantly affected some texture parameters, shear force, lipid oxidation, L values and water-holding capacity compared with control (C). Sensory analysis was carried out by an untrained panel (32) using the difference-from-control test between C and S samples to evaluate first the extent of the overall sensory difference and then the extent of sensory difference on colour, texture and flavour. Results indicated that panellists considered the intensity of the difference between C and S samples to be 'small'. Plant sterols could be used as a potential health-promoting meat ingredient with no effect on plant sterol stability but with some effects on texture and sensory characteristics. © The Author(s) 2016.

  11. Defining the needs for gas centrifuge enrichment plants advanced safeguards

    Energy Technology Data Exchange (ETDEWEB)

    Boyer, Brian David [Los Alamos National Laboratory; Erpenbeck, Heather H [Los Alamos National Laboratory; Miller, Karen A [Los Alamos National Laboratory; Swinhoe, Martyn T [Los Alamos National Laboratory; Ianakiev, Kiril [Los Alamos National Laboratory; Marlow, Johnna B [Los Alamos National Laboratory

    2010-04-05

    Current safeguards approaches used by the International Atomic Energy Agency (IAEA) at gas centrifuge enrichment plants (GCEPs) need enhancement in order to verify declared low-enriched (LEU) production, detect undeclared LEU production and detect highly enriched uranium (HEU) production with adequate detection probability using nondestructive assay (NDA) techniques. At present inspectors use attended systems, systems needing the presence of an inspector for operation, during inspections to verify the mass and {sup 235}U enrichment of declared UF{sub 6} containers used in the process of enrichment at GCEPs. In verifying declared LEU production, the inspectors also take samples for off-site destructive assay (DA) which provide accurate data, with 0.1% to 0.5% measurement uncertainty, on the enrichment of the UF{sub 6} feed, tails, and product. However, taking samples of UF{sub 6} for off-site analysis is a much more labor and resource intensive exercise for the operator and inspector. Furthermore, the operator must ship the samples off-site to the IAEA laboratory which delays the timeliness of results and interruptions to the continuity of knowledge (CofK) of the samples during their storage and transit. This paper contains an analysis of possible improvements in unattended and attended NDA systems such as process monitoring and possible on-site analysis of DA samples that could reduce the uncertainty of the inspector's measurements and provide more effective and efficient IAEA GCEPs safeguards. We also introduce examples advanced safeguards systems that could be assembled for unattended operation.

  12. Enhanced Boron Tolerance in Plants Mediated by Bidirectional Transport Through Plasma Membrane Intrinsic Proteins.

    Science.gov (United States)

    Mosa, Kareem A; Kumar, Kundan; Chhikara, Sudesh; Musante, Craig; White, Jason C; Dhankher, Om Parkash

    2016-02-23

    High boron (B) concentration is toxic to plants that limit plant productivity. Recent studies have shown the involvement of the members of major intrinsic protein (MIP) family in controlling B transport. Here, we have provided experimental evidences showing the bidirectional transport activity of rice OsPIP1;3 and OsPIP2;6. Boron transport ability of OsPIP1;3 and OsPIP2;6 were displayed in yeast HD9 mutant strain (∆fps1∆acr3∆ycf1) as a result of increased B sensitivity, influx and accumulation by OsPIP1;3, and rapid efflux activity by OsPIP2;6. RT-PCR analysis showed strong upregulation of OsPIP1;3 and OsPIP2;6 transcripts in roots by B toxicity. Transgenic Arabidopsis lines overexpressing OsPIP1;3 and OsPIP2;6 exhibited enhanced tolerance to B toxicity. Furthermore, B concentration was significantly increased after 2 and 3 hours of tracer boron ((10)B) treatment. Interestingly, a rapid efflux of (10)B from the roots of the transgenic plants was observed within 1 h of (10)B treatment. Boron tolerance in OsPIP1;3 and OsPIP2;6 lines was inhibited by aquaporin inhibitors, silver nitrate and sodium azide. Our data proved that OsPIP1;3 and OsPIP2;6 are indeed involved in both influx and efflux of boron transport. Manipulation of these PIPs could be highly useful in improving B tolerance in crops grown in high B containing soils.

  13. Phytotoxicity and Plant Productivity Analysis of Tar-Enriched Biochars

    Science.gov (United States)

    Keller, M. L.; Masiello, C. A.; Dugan, B.; Rudgers, J. A.; Capareda, S. C.

    2008-12-01

    Biochar is one of the three by-products obtained by the pyrolysis of organic material, the other two being syngas and bio-oil. The pyrolysis of biomass has generated a great amount of interest in recent years as all three by-products can be put toward beneficial uses. As part of a larger project designed to evaluate the hydrologic impact of biochar soil amendment, we generated a biochar through fast pyrolysis (less than 2 minutes) of sorghum stock at 600°C. In the initial biochar production run, the char bin was not purged with nitrogen. This inadvertent change in pyrolysis conditions produced a fast-pyrolysis biochar enriched with tars. We chose not to discard this batch, however, and instead used it to test the impact of tar-enriched biochars on plants. A suite of phytotoxicity tests were run to assess the effects of tar-rich biochar on plant germination and plant productivity. We designed the experiment to test for negative effects, using an organic carbon and nutrient-rich, greenhouse- optimized potting medium instead of soil. We used Black Seeded Simpson lettuce (Lactuca sativa) as the test organism. We found that even when tars are present within biochar, biochar amendment up to 10% by weight caused increased lettuce germination rates and increased biomass productivity. In this presentation, we will report the statistical significance of our germination and biomass data, as well as present preliminary data on how biochar amendment affects soil hydrologic properties.

  14. Study of boron behaviour in two spanish coal combustion power plants

    OpenAIRE

    Ochoa González, Raquel; Fuente Cuesta, Aida; Córdaba, Patricia; Díaz Somoano, Mercedes; Font, Oriol; López Antón, María Antonia; Querol, Xavier; Martínez Tarazona, María Rosa

    2011-01-01

    A full-scale field study was carried out at two Spanish coal-fired power plants equipped with electrostatic precipitator (ESP) and wet flue gas desulfurisation (FGD) systems to investigate the distribution of boron in coals, solid by-products, wastewater streams and flue gases. The results were obtained from the simultaneous sampling of solid, liquid and gaseous streams and their subsequent analysis in two different laboratories for purposes of comparison. Although the final aim of this study...

  15. Safeguards approaches for conversion and gas centrifuge enrichment plants

    International Nuclear Information System (INIS)

    Stanuch, C.; Whitaker, M.; Lockwood, D.; Boyer, B.

    2013-01-01

    This paper describes recent studies and investigations of new safeguards measures and inspection tools to strengthen international safeguards at GCEPs (Gas Centrifuge Enrichment Plants) and conversion plants. The IAEA has indicated that continuous, unattended process monitoring should play a central role in future safeguards approaches for conversion plants and GCEPs. Monitoring safeguards relevant information from accountancy scales, process load cells, and unit header pipes can make existing safeguards approaches more efficient by replacing repetitive, routine, labor-intensive inspection activities with automated systems. These systems can make the safeguards approach more effective by addressing more completely the safeguards objectives at these facilities. Automated collection and analysis of the data can further enable the IAEA to move towards a fully-information driven inspection regime with randomized (from the operator's perspective), short-notice inspections. The reduction in repetitive on-site inspection activities would also be beneficial to plant operators, but only if sensitive and proprietary information can be protected and the new systems prove to be reliable. New facilities that incorporate Safeguards by Design into the earliest design stages can facilitate the effective DIV (Design Information Verification) of the plant to allow the inspectors to analyze the capacity of the plant, to project maximum production from the plant, and to provide a focus on the areas in the plant where credible diversion scenarios could be attempted. Facilitating efficient nuclear material accountancy by simplifying process pipework and making flow measurement points more accessible can allow for easier estimation of plant holdup and a potential reduction in the number of person-days of inspection. Lastly, a universal monitoring standard that tracks the location, movement, and use of UF 6 cylinders may enhance the efficiency of operations at industry sites and would

  16. Proteomic analysis of naturally occurring boron tolerant plant Gypsophila sphaerocephala L. in response to high boron concentration.

    Science.gov (United States)

    Tombuloglu, Huseyin; Tombuloglu, Guzin; Sakcali, Mehmet Serdal; Turkan, Ali; Hakeem, Khalid Rehman; Alharby, Hesham F; Fahd, Shah; Abdul, Waseem Mohammed

    2017-09-01

    Gypsophila sphaerocephala is a naturally Boron (B) tolerant species that can grow around the B mining areas in Turkey, where the B concentration in soil reaches a lethal dose for plants (up to ∼8900mgkg -1 (∼140mM). While its interesting survival capacity in extremely B containing soils, any molecular research has been conducted to understand its high tolerance mechanism yet. In the present study, we have performed a proteomic analysis of this plant to understand its high tolerance towards B-stress. Seedlings of G. sphaerocephala were collected from B mining area and were adapted to greenhouse conditions. An excessive level of Boric acid (3mM)was applied to the plantlets for 24h. Total proteins were precipitated by using TCA/Acetone method. 2D-PAGE (two-dimensional polyacrylamide gel electrophoresis) analysis of the proteins was carried out. Out of 121 protein spots, 14 were differentially expressed between the control and B-exposed G. sphaerocephala roots. The peptide profile of each protein was determined by MALDI-TOF mass spectrometer after in-gel trypsin digestion. The identified proteins are involved in different mechanisms in the cell such as in antioxidant mechanism, energy metabolism, protein degradation, lipid biosynthesis and signaling pathways, indicating that G. sphaerocephala has multiple cooperating mechanisms to protect itself from high B levels. Overall, this study sheds light on to the possible regulatory switches (gene/s) controlling the B-tolerance proteins and their possible roles in plant's defense mechanism. Copyright © 2017 Elsevier GmbH. All rights reserved.

  17. Material surveillance and verification program at a uranium enriching plant

    International Nuclear Information System (INIS)

    DeVito, V.J.

    1975-01-01

    A license for a nuclear facility in the United States is approved only after a licensee demonstrates by procedure or practice that an adequate material control system exists. A license can specify acceptable material control practices. Therefore, processors in the United States receiving uranium hexafluoride (UF 6 ) from a U. S. Government-owned enriching plant can accept shipper's values for nuclear material accounting purposes if: there is surveillance during withdrawal of the UF 6 , an independent sample is obtained, and certain measurement verification is subsequently performed by the receiver or the receiver's agent. Because of the high equipment and operating costs, essentially all UF 6 processors have adopted a surveillance and verification program. A resident observer is employed to perform surveillance, obtain samples, and tamper-safe the shipping cylinders. Samples are analyzed by the receiver or by an independent laboratory. The observer determines by surveillance that withdrawals, or transfers of material, weighings, and sampling are accomplished in accordance with accepted procedures. Surveillance of the withdrawals includes observing the transfer of UF 6 from the enriching plant cylinder to the shipping cylinder(s) and the withdrawal of samples. In addition, it inclu []es observing the weighing of all cylinders associated with a sample lot of UF 6 . Following the surveillance of withdrawals, weighings, and sampling, the cylinders are made tamper-safe by the application of tamper-indicating devices. Statistics for the verification program have shown shipper and receiver measurements to be within the limits acceptable for adequate material control. (auth)

  18. Permit issued for expansion of the Gronau uranium enrichment plant

    International Nuclear Information System (INIS)

    2005-01-01

    Over the next few years, the Gronau Uranium Enrichment Plant (UAG) will be able to raise its capacity in steps from 1 800 tonnes to 4 500 tonnes SWU per annum. This development in steps depends on the extent to which demand on the world market can be turned into contracts for Urenco. After a procedure taking more than six years to complete, Urenco Deutschland GmbH was issued the required permit by the North Rhine-Westphalian State Ministry for Transport, Energy, and Planning on February 14 this year. The permit was preceded by the drafting and examination of two safety reports of several hundred pages each, and of over 1 000 detailed documents. The application documents were examined by a large number of expert consultants and public authorities from all over Germany acting on behalf of the nuclear licensing authority. Urenco Ltd. sells enrichment services worldwide, at present holding a share of approx. 19% of the world market for uranium separative work. Although this world market is not going to grow for a foreseeable period of time, Urenco is expanding its capacities. This is based on the latest centrifuge technology characterized by extremely low power consumption and high availability. It replaces diffusion technology, which currently holds a share of approx. 40% of the world market. (orig.)

  19. Long-term disposal of enrichment plant tails

    International Nuclear Information System (INIS)

    1979-08-01

    Approximately 97% of the uranium fed to the isotope separation plants is recovered as tails containing nominally 0.2 wt percent U-235. Essentially all this tails material produced in the past, as well as that currently being generated, is stored as solidified UF 6 in steel cylinders. This report describes a stand-alone, 10 tU/day facility for converting the UF 6 to a stable uranium oxide powder amenable to long-term storage in steel drums. The conversion is accomplished in a two-step process in which the UF 6 is first reduced to UF 4 with hydrogen in a tower reactor and then the UF 4 is pyrohydrolyzed to UO 2 with steam in a three-stage screw reactor. One reduction reactor supplies the feed for three pyrohydrolysis reactor lines. Included in the process flow sheets and reactor design details are descriptions of the major auxiliary components for vaporizing and feeding the UF 6 , a dissociator for ammonia used as a hydrogen source, a system for recovering anhydrous hydrogen fluoride, and a reactor system for the disposal of hydrous hydrogen fluoride. Two of the nominal 10 tU/day plants would be required to handle the tails produced in isotope separation plants supplying enriched uranium to a nuclear power industry with a generation capacity of 50 GWe per year

  20. Systems approach used in the Gas Centrifuge Enrichment Plant

    International Nuclear Information System (INIS)

    Rooks, W.A. Jr.

    1982-01-01

    A requirement exists for effective and efficient transfer of technical knowledge from the design engineering team to the production work force. Performance-Based Training (PBT) is a systematic approach to the design, development, and implementation of technical training. This approach has been successfully used by the US Armed Forces, industry, and other organizations. The advantages of the PBT approach are: cost-effectiveness (lowest life-cycle training cost), learning effectiveness, reduced implementation time, and ease of administration. The PBT process comprises five distinctive and rigorous phases: Analysis of Job Performance, Design of Instructional Strategy, Development of Training Materials and Instructional Media, Validation of Materials and Media, and Implementation of the Instructional Program. Examples from the Gas Centrifuge Enrichment Plant (GCEP) are used to illustrate the application of PBT

  1. Study of the boron distribution in pea and alfalfa plants using SSNTD

    International Nuclear Information System (INIS)

    Li Jianming; Inst. for Application of Atomic Energy)" data-affiliation=" (Chinese Academy of Agricultural Sciences, Beijing, BJ (China)> Inst. for Application of Atomic Energy)" >Deng Hongmin

    1988-01-01

    The distribution of boron in pea (Pisum sativum L.) and alfalfa (Medicago sativa L.) was determined by using SSNTD. The results show that boron concentrations in leaves are highest, furthermore boron concentrations of the base leaves are higher than those of the top leaves. Among flower tissues, calyx has the highest boron concentration

  2. 78 FR 30342 - United States Enrichment Corporation, Paducah Gaseous Diffusion Plant

    Science.gov (United States)

    2013-05-22

    ... COMMISSION United States Enrichment Corporation, Paducah Gaseous Diffusion Plant AGENCY: Nuclear Regulatory... Renewal of its Certificate of Compliance (CoC) for the Paducah Gaseous Diffusion Plant (PGDP). The existing CoC (No. GDP-1) authorizes operation of a uranium enrichment facility in Paducah, Kentucky. The...

  3. 78 FR 65389 - United States Enrichment Corporation, Paducah Gaseous Diffusion Plant

    Science.gov (United States)

    2013-10-31

    ... COMMISSION United States Enrichment Corporation, Paducah Gaseous Diffusion Plant AGENCY: Nuclear Regulatory...) for the Paducah Gaseous Diffusion Plant (PGDP). The current CoC for PGDP is set to expire on December... operation of a uranium enrichment facility in Paducah, Kentucky, using the gaseous ] diffusion process. PGDP...

  4. Facile synthesis of a boronate affinity sorbent from mesoporous nanomagnetic polyhedral oligomeric silsesquioxanes composite and its application for enrichment of catecholamines in human urine

    Energy Technology Data Exchange (ETDEWEB)

    He, Haibo, E-mail: hbhe2006@shu.edu.cn [Department of Chemistry, Shanghai University, Shanghai 200444 (China); Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), Department of Chemistry, Wuhan University, Wuhan 430072 (China); Zhou, Ziqing; Dong, Chen; Wang, Xin [Department of Chemistry, Shanghai University, Shanghai 200444 (China); Yu, Qiong-wei [Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), Department of Chemistry, Wuhan University, Wuhan 430072 (China); Lei, Yunyi; Luo, Liqiang [Department of Chemistry, Shanghai University, Shanghai 200444 (China); Feng, Yuqi [Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), Department of Chemistry, Wuhan University, Wuhan 430072 (China)

    2016-11-09

    A boronate-decorated nanomagnetic organic-inorganic hybrid material was facilely synthesized by utilizing the nanomagnetic polyhedral oligomeric silsesquioxanes (POSS) composite (Fe{sub 3}O{sub 4}@POSS) as the base platform. A simple copolymerization occurred between 3-acrylamidophenylboronic acid (AAPBA) and the residual end vinyl groups supplied by the substrate. Here the special emphasis was placed on the octavinyl POSS, which not only acted as the building blocks for a hybrid architecture but also facilitated the process of grafting boronate groups onto the surface of POSS based nanomagnetic composite (Fe{sub 3}O{sub 4}@POSS). The successful immobilization of affinity ligand-AAPBA on the Fe{sub 3}O{sub 4}@POSS was confirmed by Fourier transform infrared (FT-IR), elemental analysis, inductively coupled plasma atomic emission spectrometer (ICP-AES), field emission scanning electron microscope. A magnetic solid-phase extraction (MSPE) for cis-diols enrichment was developed using the as-prepared Fe{sub 3}O{sub 4}@POSS-AAPBA material as an affinity sorbent and three catecholamines (CAs), namely noradrenaline, epinephrine and isoprenaline, as model analytes. Under the optimal extraction conditions, sensitive and simultaneous analysis of three CAs from the urine sample was achieved by high-performance liquid chromatography with UV detection (HPLC-UV). The limits of detection (LOD, S/N = 3) and the limits of quantitation (LOQ, S/N = 10) for the target analytes were 0.81–1.32 ng mL{sup −1} and 2.70–4.40 ng mL{sup −1}, respectively. Also good recoveries (85.5–101.7%) and repeatability (RSD≤10.1%) were obtained by this method. This work not only showed a facility for the utilization of Fe{sub 3}O{sub 4}@POSS as a substrate for constructing a boronate functionalized nanomagnetic sorbent, but also demonstrated the capability of the derived material for recognition of trace amount of cis-diols biomolecules presented in complicated biological matrices

  5. Measurement of the enrichment of uranium-hexafluoride gas in product pipes in the centrifuge enrichment plant at Almelo

    International Nuclear Information System (INIS)

    Packer, T.W.; Lees, E.W.; Aaldijk, J.K.; Harry, R.J.S.

    1987-09-01

    One of the objectives of safeguarding centrifuge enrichment plants is to apply non-destructive measurements inside the cascade area to confirm that the enrichment level is in the low enriched uranium range. Research in the UK and USA has developed a NDA instrument which can confirm the presence of low enriched uranium on a rapid go/no go basis in cascade header pipework of their centrifuge enrichment plants. The instrument is based on a gamma spectroscopic measurement coupled with an X-ray fluorescence analysis. This report gives the results of measurements carried out at Almelo by the UKAEA Harwell, ECN Petten and KFA Juelich to determine if these techniques could be employed at Almelo and Gronau. The energy dispersive X-ray fluorescence analysis has been applied to determine the total mass of uranium in the gas phase, and the deposit correction technique and the two geometry technique have been applied at Almelo to correct the measured gamma intensities for those emitted by the deposit. After an executive summary the report discusses the principles of the two correction methods. A short description of the equipment precedes the presentation of the results of the measurements and the discussion. After the conclusions the report contains two appendices which contain the derivation of the formulae for the deposit correction technique and a discussion of the systematic errors of this technique. 8 figs.; 11 refs.; 6 tables

  6. Effects of foliar boron application on seed composition, cell wall boron, and seed δ(15)N and δ(13)C isotopes in water-stressed soybean plants.

    Science.gov (United States)

    Bellaloui, Nacer; Hu, Yanbo; Mengistu, Alemu; Kassem, My A; Abel, Craig A

    2013-01-01

    Limited information is available on the effects of foliar boron (B) application on soybean seed composition. The objective of this research was to investigate the effects of foliar B on seed composition (protein, oil, fatty acids, and sugars). Our hypothesis was that since B is involved in nitrogen and carbon metabolism, it may impact seed composition. A repeated greenhouse experiment was conducted where half of the soybean plants was exposed to water stress (WS) and the other half was well-watered. Foliar boron (FB) in the form of boric acid was applied twice at a rate of 1.1 kg ha(-1). The first application was during flowering stage, and the second application was during seed-fill stage. Treatments were water stressed plants with no FB (WS-B); water stressed plants with FB (WS+B); watered plants without FB (W-B), and watered plants with FB (W+B). The treatment W-B was used as a control. Comparing with WS-B plants, B concentration was the highest in leaves and seed of W+B plants (84% increase in leaves and 73% in seed). Seeds of W+B plants had higher protein (11% increase), oleic acid (27% increase), sucrose (up to 40% increase), glucose, and fructose comparing with W-B. However, seed stachyose concentrations increased by 43% in WS-B plants seed compared with W-B plants. Cell wall (structural) B concentration in leaves was higher in all plants under water stress, especially in WS-B plants where the percentage of cell wall B reached up to 90%. Water stress changed seed δ(15)N and δ(13)C values in both B applied and non-B applied plants, indicating possible effects on nitrogen and carbon metabolism. This research demonstrated that FB increased B accumulation in leaves and seed, and altered seed composition of well-watered and water stressed plants, indicating a possible involvement of B in seed protein, and oleic and linolenic fatty acids. Further research is needed to explain mechanisms of B involvement in seed protein and fatty acids.

  7. Effects of foliar boron application on seed composition, cell wall boron, and seed δ15N and δ13C isotopes in water-stressed soybean plants

    Science.gov (United States)

    Bellaloui, Nacer; Hu, Yanbo; Mengistu, Alemu; Kassem, My A.; Abel, Craig A.

    2013-01-01

    Limited information is available on the effects of foliar boron (B) application on soybean seed composition. The objective of this research was to investigate the effects of foliar B on seed composition (protein, oil, fatty acids, and sugars). Our hypothesis was that since B is involved in nitrogen and carbon metabolism, it may impact seed composition. A repeated greenhouse experiment was conducted where half of the soybean plants was exposed to water stress (WS) and the other half was well-watered. Foliar boron (FB) in the form of boric acid was applied twice at a rate of 1.1 kg ha−1. The first application was during flowering stage, and the second application was during seed-fill stage. Treatments were water stressed plants with no FB (WS–B); water stressed plants with FB (WS+B); watered plants without FB (W–B), and watered plants with FB (W+B). The treatment W–B was used as a control. Comparing with WS–B plants, B concentration was the highest in leaves and seed of W+B plants (84% increase in leaves and 73% in seed). Seeds of W+B plants had higher protein (11% increase), oleic acid (27% increase), sucrose (up to 40% increase), glucose, and fructose comparing with W–B. However, seed stachyose concentrations increased by 43% in WS–B plants seed compared with W–B plants. Cell wall (structural) B concentration in leaves was higher in all plants under water stress, especially in WS–B plants where the percentage of cell wall B reached up to 90%. Water stress changed seed δ15N and δ13C values in both B applied and non-B applied plants, indicating possible effects on nitrogen and carbon metabolism. This research demonstrated that FB increased B accumulation in leaves and seed, and altered seed composition of well-watered and water stressed plants, indicating a possible involvement of B in seed protein, and oleic and linolenic fatty acids. Further research is needed to explain mechanisms of B involvement in seed protein and fatty acids. PMID:23888163

  8. Deficiency and toxicity of boron: Alterations in growth, oxidative damage and uptake by citrange orange plants.

    Science.gov (United States)

    Shah, Asad; Wu, Xiuwen; Ullah, Abid; Fahad, Shah; Muhammad, Riaz; Yan, Lei; Jiang, Cuncang

    2017-11-01

    Boron (B) deficiency and toxicity are the major factors that affect plant growth and yield. The present study revealed the effect of B deficiency and toxicity on plant growth, morphology, physiology, and cell structure. A hydroponic culture experiment was conducted with five B levels, B deficient (B0), sufficient (B20, B10, B40) and toxic (B100). Our results show that both B deficient as well as excess level inhibit plant growth. In B deficiency, the major visible symptoms were appeared in roots, while B excess burned the leaf margin of older leaves. The antioxidant enzymes including superoxide dismutase (SOD), peroxidase (POD), catalase (CAT) and ascorbate peroxidase (APX) decreased at B deficiency and also decreased up to some extent at B excess, while in sufficient treatments, the higher antioxidant enzymes were found at B20. In addition, the MDA concentration decreased at B deficiency and increased with B concentration. Moreover, the photosynthetic rate, transpiration rate, stomatal conductance, leaf gas exchange and intercellular CO 2 were reduced at both B deficiency as well as excess and higher at sufficient B20 treatment significantly. The chlorophyll and carotenoid content increased at B20 treatment, while decreased at B deficiency and excess. The middle lamellae of cell wall were found thick at B excess and normal at B20. The current study revealed that B deficiency as well as excess concentration affect plant growth and various morpho-physiological processes. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. 76 FR 53494 - In the Matter of United States Enrichment Corporation; Paducah Gaseous Enrichment Plant...

    Science.gov (United States)

    2011-08-26

    ... removable contamination, unless otherwise authorized by Health Physics. USEC- Paducah is required by... involved in the routine activity of swapping cylinders from the enrichment cascade in the 337A feed...) regarding activities at the Paducah facility. The purpose of the investigation was to determine whether an...

  10. Hyb-Seq: combining target enrichment and genome skimming for plant phylogenomics

    Science.gov (United States)

    Kevin Weitemier; Shannon C.K. Straub; Richard C. Cronn; Mark Fishbein; Roswitha Schmickl; Angela McDonnell; Aaron. Liston

    2014-01-01

    • Premise of the study: Hyb-Seq, the combination of target enrichment and genome skimming, allows simultaneous data collection for low-copy nuclear genes and high-copy genomic targets for plant systematics and evolution studies. • Methods and Results: Genome and transcriptome assemblies for milkweed ( Asclepias syriaca ) were used to design enrichment probes for 3385...

  11. Boron compartmentation in roots of sunflower plants of different boron status: A study using the stable isotopes 10B and 11B adopting two independent approaches

    International Nuclear Information System (INIS)

    Pfeffer, H.; Dannel, F.; Roemheld, V.

    2001-01-01

    The intracellular compartmentation of boron (B) in roots of sunflower plants precultured with 100 μM B (high B) or 1 μM B (low B) was studied using two independent approaches. In the first approach, short-term efflux studies using the stable isotopes 11 B and 10 B were carried out. In roots of high B plants, the calculated concentrations of B (nmol g FW -1 ) were 52.6 in the cell wall, 7.5 in the vacuole, 27.1 in the cytosol and 48.0 in the free space. In roots of low B plants, the concentrations of B (nmol g FW -1 ) were 43.4 in the cell wall, 2.8 in the vacuole, 17.9 in the cytosol and almost zero in the free space. Although the B supply differed by a factor 100, the B concentrations in the cytosol and the vacuole of low B plants were 66 and 37% of the respective concentrations in high B plants. This suggests an additional role for B in plant metabolism, besides its function in the cell wall. In the second approach, root B pools (cell sap and water-insoluble residue) were determined for comparison, and found to be in good agreement with the results from the efflux study. (au)

  12. A combination of "thiol-ene" click chemistry and surface initiated atom transfer radical polymerization: Fabrication of boronic acid functionalized magnetic graphene oxide composite for enrichment of glycoproteins.

    Science.gov (United States)

    Su, Jie; He, Xiwen; Chen, Langxing; Zhang, Yukui

    2018-04-01

    An efficient glycoproteins enrichment platform is one of vital preprocessing steps in biomarker research and in particular glycoproteomics. In this work, a well-defined boronic acid functionalized magnetic graphene oxide nanocomposite (Fe 3 O 4 -GO@PAAPBA) was synthesized for the selective enrichment of glycoproteins from complex biological samples via a novel strategy based on the "thiol-ene" click chemistry and surface initiated atom transfer radical polymerization (SI-ATRP). The initiator of ATRP was anchored to the surface of substrate through "thiol-ene" click reaction. The product Fe 3 O 4 -GO@PAAPBA was successfully synthesized in following SI-ATRP. The Fe 3 O 4 -GO@PAAPBA nanocomposite was characterized by transmission electron microscopy (TEM), Fourier transform-infrared spectroscopy (FTIR), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), vibrating sample magnetometry (VSM) and thermogravimetric analysis. The adsorption capacity of Fe 3 O 4 -GO@PAAPBA towards ovalbumin (OVA) and transferrin (Trf) is 471mgg -1 and 450mgg -1 , respectively. The nanocomposite also featured good selectivity to glycoproteins in the mixture of glycoproteins and non-glycoproteins at alkaline (pH 9.0) and physiological conditions (pH 7.4). Furthermore, it can be applied to extract glycoproteins directly from egg white samples. These results have indicated that Fe 3 O 4 -GO@PAAPBA was a potential affinity material in glycoprotein analysis. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Targeted enrichment strategies for next-generation plant biology

    Science.gov (United States)

    Richard Cronn; Brian J. Knaus; Aaron Liston; Peter J. Maughan; Matthew Parks; John V. Syring; Joshua. Udall

    2012-01-01

    The dramatic advances offered by modem DNA sequencers continue to redefine the limits of what can be accomplished in comparative plant biology. Even with recent achievements, however, plant genomes present obstacles that can make it difficult to execute large-scale population and phylogenetic studies on next-generation sequencing platforms. Factors like large genome...

  14. FACE: Free-Air CO[sub 2] Enrichment for plant research in the field

    Energy Technology Data Exchange (ETDEWEB)

    Hendrey, G.R. (ed.)

    1992-08-01

    Research programs concerning the effects of Carbon Dioxide(CO)[sub 2] on cotton plants are described. Biological responses studied include foliage response to CO[sub 2] fluctuations; yield of cotton exposed to CO[sub 2] enrichment; responses of photosynthesis and stomatal conductance to elevated CO[sub 2] in field-grown cotton; cotton leaf and boll temperatures; root response to CO[sub 2] enrichment; and evaluations of cotton response to CO[sub 2] enrichment with canopy reflectance observations.

  15. FACE: Free-Air CO{sub 2} Enrichment for plant research in the field

    Energy Technology Data Exchange (ETDEWEB)

    Hendrey, G.R. [ed.

    1992-08-01

    Research programs concerning the effects of Carbon Dioxide(CO){sub 2} on cotton plants are described. Biological responses studied include foliage response to CO{sub 2} fluctuations; yield of cotton exposed to CO{sub 2} enrichment; responses of photosynthesis and stomatal conductance to elevated CO{sub 2} in field-grown cotton; cotton leaf and boll temperatures; root response to CO{sub 2} enrichment; and evaluations of cotton response to CO{sub 2} enrichment with canopy reflectance observations.

  16. Experimental tolerance to boron of the plant species Nicotiana glauca, Jacaranda mimosifolia, Tecoma stans, Medicago sativa y Spinacea oleracea in Argentina

    International Nuclear Information System (INIS)

    Viana, Marta L. de; Albarracin Franco, Silvia

    2008-01-01

    The activity of the borate deposits industries constitutes a point source and diffuse pollution of air, soil and water. Therefore, the study and experimentation on possible ways to offset this impact is a priority. A relatively new technique to decontaminate soils is phytoremediation, which uses plants and associated microorganisms. The first step is to identify tolerant plant species, which is the focus of this work. An experiment was conducted in the laboratory to evaluate the germination, survival and growth of different species in different concentrations of boron. At the beginning and end of the experiment was determined concentration of boron in the substrate for each treatment and for substrates with and without vegetation. Significant differences due to treatment, the species and species-treatment interaction. M. sativa, N. glauca and J. mimosifolia were the species most tolerant to boron. The other species showed a decrease in all variables-response function of the concentration of the contaminant. All had low survival in the highest concentration. The decrease of boron was highest in the treatment of 30 ppm of boron with M. sativa and the lowest was recorded in the treatment of 20 ppm of boron with J. mimosifolia and 30 ppm of boron with T. stans and S. oleracea. It is concluded that N. glauca, M. sativa and J. mimosifolia could be considered as promising remediation. (author) [es

  17. Research of boron concentration measurement of nuclear power plant based on SOPC

    International Nuclear Information System (INIS)

    Dai Hangyang; Deng Sheng; Cui Can

    2014-01-01

    According to the requirements of the integrated and miniaturization boron concentration measurement system, the data acquisition system based on SOPC (System on a programmable chip) achieves the acquisition of the pulse signals and temperature signals, and can decrease the transmitting interference and improve the accuracy of boron concentration measurement. According to the principle of boron concentration measurement, this paper firstly introduces the structure of the data acquisition system, and then carries on the detailed research on temperature acquisition module, pulse acquisition module, digital potentiometer, self-test control module, on-sit display module and telecommunication module. So the multifunctional data acquisition system is integrated into a more complete and flexible SOPC. At last, the testing results verify the reliability, accuracy and anti-jamming capability of boron concentration measurement system based on SOPC. (authors)

  18. A data transmission system for the centrifuge enrichment plant safeguards project

    International Nuclear Information System (INIS)

    Hesse, E.W.

    1987-04-01

    A novel data transmission system was developed to enable the Australian Safeguards Office (ASO) in Sydney to monitor remotely the running of an experimental enrichment facility at the Lucas Heights Reserch Laboratories, using Telecom telephone lines. The system allowed ASO to monitor the enrichment, flows and activity in sensitive areas of the plant by means of a master computer at ASO and a slave computer at Lucas Heights. The slave computer sent requested data and scanned video pictures to determine intrusive changes to the plant. Detailed descriptions of the transmission system and method of operation are given, together with an outline of experience obtained during a three-month surveillance of the facility

  19. Studies on Separation Process and Production Technology of Boron Isotope

    OpenAIRE

    LI Jian-ping

    2014-01-01

    The boron isotopes separation test was performed by chemical exchange reaction in the benzene ether -three boron fluoride system, which resulted to the boron isotopic enrichment of -10 in the liquid phase, the boron isotopic enrichment of -11 in the gas phase. After then, boron isotope separation trial production has been finished. In this process, the exchange column and complex tower normal operating parameters and the complex tower technology have been obtained, the problems of material di...

  20. [Experimental tolerance to boron of the plant species Nicotiana glauca, Jacaranda mimosifolia, Tecoma stans, Medicago sativa y Spinacea oleracea in Argentina].

    Science.gov (United States)

    de Viana, Marta L; Albarracín Franco, Silvia

    2008-09-01

    The activity of boron industries is a punctual and diffuse source of air, soil and water pollution. Therefore, it is a priority to study possible ways of reducing this impact. A relatively new technology for reducing soil pollution is phytoremediation, which uses plants and associate microorganisms. The first step in phytoremediation is to detect tolerant plant species, which is the objective of this work. A laboratory experiment to assess the germination, survival and growth of different species at different boron concentrations was carried out following a factorial design with two factors: plant species and boron concentration. Boron concentrations were determined at the beginning and the end of the experiment, taking into account substrates with and without vegetation. We found significant differences for treatment, species and the interaction species*treatment. N. glauca, M. sativa and J. mimosifolia were the most tolerant species. The other species had a decrease in the response variables, with the concentration of the pollutant. All the species had a low survival at the highest boron concentration. The reduction in boron concentration at the end of the experiment was higher in the 30 ppm treatment with M. sativa and the lower was registered in the 20 ppm treatment with J. mimosifolia and in 30 ppm with T. stans and S. oleraceae. We conclude that N. glauca, M. sativa and J. mimosifolia can be considered in remediation plans.

  1. Socioeconomic effects of the DOE Gas Centrifuge Enrichment Plant. Volume 1: methodology and analysis

    International Nuclear Information System (INIS)

    1979-01-01

    The socioeconomic effects of the Gas Centrifuge Enrichment Plant being built in Portsmouth, Ohio were studied. Chapters are devoted to labor force, housing, population changes, economic impact, method for analysis of services, analysis of service impacts, schools, and local government finance

  2. 78 FR 66779 - United States Enrichment Corporation, Paducah Gaseous Diffusion Plant, Including On-Site Leased...

    Science.gov (United States)

    2013-11-06

    ... DEPARTMENT OF LABOR Employment and Training Administration [TA-W-82,862] United States Enrichment... Consultants, Inbounds Engineering, Llc, Matrix Engineering, Manpower Inc., Bartlett Nuclear, Inc., C-Plant...-site leased workers from Diversified Management Consultants, Inbounds Engineering LLC, Matrix...

  3. Axial enrichment profile in advance nuclear energy power plant at supercritical-pressures

    Energy Technology Data Exchange (ETDEWEB)

    Tashakor, S. [Nuclear Science and Technology Research Institute (NSTRI), Tehran (Iran, Islamic Republic of). Reactor Research School; Islamic Azad Univ., Shiraz (Iran, Islamic Republic of). Dept. of Nuclear Engineering; Zarifi, E. [Nuclear Science and Technology Research Institute (NSTRI), Tehran (Iran, Islamic Republic of). Reactor Research School; Salehi, A.A. [Sharif University of Technology, Tehran (Iran, Islamic Republic of). Dept. of Nuclear Energy

    2015-12-15

    The High-Performance Light Water Reactor (HPLWR) is the European version of the advance nuclear energy power plant at Supercritical-pressure. A light water reactor at supercritical pressure, being currently under design, is the new generation of nuclear reactors. The aim of this study is to predict the HPLWR neutronic behavior of the axial enrichment profile with an average enrichment of 5 w/o U-235. Neutronic calculations are performed using WIMS and CITATION codes. Changes in neutronic parameter, such as Power Peaking Factor (PPF) are discussed in this paper.

  4. Elevated CO2 affects plant responses to variation in boron availability

    Science.gov (United States)

    Effects of elevated CO2 on N relations are well studied, but effects on other nutrients, especially micronutrients, are not. We investigated effects of elevated CO2 on response to variation in boron (B) availability in three unrelated species: geranium (Pelargonium x hortorum), barley (Hordeum vulga...

  5. Compression and Associated Properties of Boron Carbide

    Science.gov (United States)

    2008-12-01

    Klandadze, G.I., and Eristavi, A.M., 1999: IR- Active Phonons and Structure Elements of Isotope - Enriched Boron Carbide, J. Sol. State Chem. 154, 79- 86...COMPRESSION AND ASSOCIATED PROPERTIES OF BORON CARBIDE D. P. Dandekar*and J. A. Ciezak Army Research Laboratory, APG, MD 21005 M. Somayazulu...of the observed loss of shear strength in boron carbide under plane shock wave compression to amorphization in boron carbide under triaxial stress

  6. Preliminary analysis of 500 MWt MHD power plant with oxygen enrichment

    Science.gov (United States)

    1980-04-01

    An MHD Engineering Test Facility design concept is analyzed. A 500 MWt oxygen enriched MHD topping cycle integrated for combined cycle operation with a 400 MWe steam plant is evaluated. The MHD cycle uses Montana Rosebud coal and air enriched to 35 mole percent oxygen preheated to 1100 F. The steam plant is a 2535 psia/1000 F/1000 F reheat recycle that was scaled down from the Gilbert/Commonwealth Reference Fossil Plant design series. Integration is accomplished by blending the steam generated in the MHD heat recovery system with steam generated by the partial firing of the steam plant boiler to provide the total flow requirement of the turbine. The major MHD and steam plant auxiliaries are driven by steam turbines. When the MHD cycle is taken out of service, the steam plant is capable of stand-alone operation at turbine design throttle flow. This operation requires the full firing of the steam plant boiler. A preliminary feasibility assessment is given, and results on the system thermodynamics, construction scheduling, and capital costs are presented.

  7. Microsatellite markers isolated from the wild medicinal plant Centella asiatica (Apiaceae) from an enriched genomic library.

    Science.gov (United States)

    Rakotondralambo, Soaharin'ny Ony Raoseta; Lussert, Alexandra; Rivallan, Ronan; Danthu, Pascal; Noyer, Jean-Louis; Baurens, Franc-Christophe

    2012-04-01

    Microsatellite markers for Centella asiatica, an important medicinal herb, were developed and characterized to promote genetic and molecular studies. A GA/GT-enriched genomic library was constructed from an accession from Madagascar. Roughly 75% of the 768 clones of the enriched library contained microsatellites. Eighty sequences containing microsatellites were obtained from 96 positive clones. Specific primers were designed for 20 loci, and 17 of them displayed polymorphism when screened across 17 C. asiatica accessions, with an average of 4.3 alleles per locus. The observed and expected heterozygosity values averaged 0.114 and 0.379, respectively. This is the first report constructing an enriched genomic library and identifying microsatellite markers from C. asiatica. These 17 polymorphic microsatellite markers are a useful resource for this plant, applicable for diversity studies, pedigree analyses, and genetic mapping.

  8. Gas centrifuge enrichment plants inspection frequency and remote monitoring issues for advanced safeguards implementation

    Energy Technology Data Exchange (ETDEWEB)

    Boyer, Brian David [Los Alamos National Laboratory; Erpenbeck, Heather H [Los Alamos National Laboratory; Miller, Karen A [Los Alamos National Laboratory; Ianakiev, Kiril D [Los Alamos National Laboratory; Reimold, Benjamin A [Los Alamos National Laboratory; Ward, Steven L [Los Alamos National Laboratory; Howell, John [GLASGOW UNIV.

    2010-09-13

    Current safeguards approaches used by the IAEA at gas centrifuge enrichment plants (GCEPs) need enhancement in order to verify declared low enriched uranium (LEU) production, detect undeclared LEU production and detect high enriched uranium (BEU) production with adequate probability using non destructive assay (NDA) techniques. At present inspectors use attended systems, systems needing the presence of an inspector for operation, during inspections to verify the mass and {sup 235}U enrichment of declared cylinders of uranium hexafluoride that are used in the process of enrichment at GCEPs. This paper contains an analysis of how possible improvements in unattended and attended NDA systems including process monitoring and possible on-site destructive analysis (DA) of samples could reduce the uncertainty of the inspector's measurements providing more effective and efficient IAEA GCEPs safeguards. We have also studied a few advanced safeguards systems that could be assembled for unattended operation and the level of performance needed from these systems to provide more effective safeguards. The analysis also considers how short notice random inspections, unannounced inspections (UIs), and the concept of information-driven inspections can affect probability of detection of the diversion of nuclear material when coupled to new GCEPs safeguards regimes augmented with unattended systems. We also explore the effects of system failures and operator tampering on meeting safeguards goals for quantity and timeliness and the measures needed to recover from such failures and anomalies.

  9. Pscroph, a parasitic plant EST database enriched for parasite associated transcripts

    Directory of Open Access Journals (Sweden)

    Tomilov Alexey A

    2005-11-01

    Full Text Available Abstract Background Parasitic plants in the Orobanchaceae develop invasive root haustoria upon contact with host roots or root factors. The development of haustoria can be visually monitored and is rapid, highly synchronous, and strongly dependent on host factor exposure; therefore it provides a tractable system for studying chemical communications between roots of different plants. Description Triphysaria is a facultative parasitic plant that initiates haustorium development within minutes after contact with host plant roots, root exudates, or purified haustorium-inducing phenolics. In order to identify genes associated with host root identification and early haustorium development, we sequenced suppression subtractive libraries (SSH enriched for transcripts regulated in Triphysaria roots within five hours of exposure to Arabidopsis roots or the purified haustorium-inducing factor 2,6 dimethoxybenzoquinone. The sequences of over nine thousand ESTs from three SSH libraries and their subsequent assemblies are available at the Pscroph database http://pscroph.ucdavis.edu. The web site also provides BLAST functions and allows keyword searches of functional annotations. Conclusion Libraries prepared from Triphysaria roots treated with host roots or haustorium inducing factors were enriched for transcripts predicted to function in stress responses, electron transport or protein metabolism. In addition to parasitic plant investigations, the Pscroph database provides a useful resource for investigations in rhizosphere interactions, chemical signaling between organisms, and plant development and evolution.

  10. Enhancing the lead phytostabilization in wetland plant Juncus effusus L. through somaclonal manipulation and EDTA enrichment

    Directory of Open Access Journals (Sweden)

    Ullah Najeeb

    2017-05-01

    Full Text Available We investigated the role of ethylene diamine tetra-acetic acid (EDTA and somaclonal manipulation on improving lead (Pb phytostabilization in mat rush (Juncus effusus L.. Seedlings were raised from seeds and callus to study variations in Pb uptake and tolerance. The seedlings were treated with 0.5 and 1.0 mM Pb as alone, and each with 2.5 and 5.0 mM of EDTA. Plants grown from both sources accumulated relatively larger Pb contents in their root tissues that were further enhanced by EDTA supplementation in the hydroponics medium. The tendency of storing higher Pb contents in roots compared to shoots in J. effusus was also evident from lower translocation factor (TF value that facilitated the plants to avoid from Pb-induced shoot injury. Callus grown plants were more responsive to EDTA amendment showing improved growth, Pb uptake and chlorophyll contents under Pb stress. Both kinds of J. effusus plants tolerated Pb toxicity by modifying antioxidative enzyme activities. Enrichment of Pb-treated media with EDTA further elevated enzymic activities of plant roots contributing to defy Pb-induced oxidative burst. Thus, plant improvement through somaclonal manipulation in J. effusus along with EDTA enrichment could be an appropriate technique for phytostabilization of Pb-contaminated environments.

  11. Integrated Information Technology Framework for Analysis of Data from Enrichment Plants to Support the Safeguards Mission

    Energy Technology Data Exchange (ETDEWEB)

    Marr, Clifton T.; Thurman, David A.; Jorgensen, Bruce V.

    2008-07-15

    ABSTRACT Many examples of software architectures exist that support process monitoring and analysis applications which could be applied to enrichment plants in a fashion that supports the Safeguards Mission. Pacific Northwest National Laboratory (PNNL) has developed mature solutions that will provide the framework to support online statistical analysis of enrichment plans and the entire nuclear fuel cycle. Most recently, PNNL has developed a refined architecture and supporting tools that address many of the common problems analysis and modeling environments experience: pipelining, handling large data volumes, and real-time performance. We propose the architecture and tools may be successfully used in furthering the goals of nuclear material control and accountability as both an aid to processing plant owners and as comprehensive monitoring for oversight teams.

  12. Method for estimate the economic characteristics of an uranium enrichment plant by gaseous diffusion

    International Nuclear Information System (INIS)

    Berault, J.C.

    1975-01-01

    To estimate the economic characteristics of an uranium enrichment plant by gaseous diffusion is to determine the prospective price of the separative work unit to which leads the concerned technology, and to collect the data allowing to ascertain that this price remains in the area of development of the prices forecasted by the other projects. The prospective price estimated by the promoter is the synthesis of the components of the go decision and which are a potential market and a comprehensive industrially proven plant design, including the basic economic and technical data of the project. Procedures for estimating these components and their synthesis, exclusive of financing problems are reviewed [fr

  13. Development of a computer systems for operational data acquisition of uranium isotopic enrichment pilot plant

    International Nuclear Information System (INIS)

    Maia, W.M.C.

    1985-01-01

    A pilot plant for uranium enrichment using the jet nozzle process was transfered from Federal Republic of Germany to Brazil, to train Brazilian technicist in its operation and to improve the process. This pilot plant is monitored by a data acquisition system and the possibility of faulty events would cause serious dificulties, as far as maintenance is concerned (for instance, unvailable special components). It is described the development of a new system, which is proposed in order to minimize difficulties with maintenance that utilizes in the assembling integrated circuits of large scale of integration. It is controlled by a microcomputer. (Author) [pt

  14. Influence of sediment organic enrichment and water alkalinity on growth of aquatic isoetid and elodeid plants

    DEFF Research Database (Denmark)

    Raun, Ane-Marie Løvendahl; Borum, Jens; Jensen, Kaj Sand

    2010-01-01

    lakes, the vegetation has rarely regained its former composition and coverage. Patterns of recovery may depend on local alkalinity because HCO3- stimulates photosynthesis of elodeids and not of isoetids. In laboratory growth experiments with two isoetids (Lobelia dortmanna and Littorella uniflora......) and two elodeids (Potamogeton crispus and P. perfoliatus), we test whether organic enrichment of lake sediments has a long-lasting influence by: (i) reducing plant growth because of oxygen stress on plant roots and (ii) inhibiting growth more for isoetids than elodeids. We also test whether (iii...

  15. Irradiation program of slightly enriched fuel elements at the Atucha I nuclear power plant

    International Nuclear Information System (INIS)

    Casario, J.A.; Cesario, R.H.; Perez, R.A.; Sidelnik, J.I.

    1987-01-01

    An irradiation program of fuel elements with slightly enriched uranium is implemented, tending to the homogenization of core at Atucha I nuclear power plant. The main benefits of the enrichment program are: a) to extend the average discharge burnup of fuel elements, reducing the number of elements used to generate the same amount of energy. This implies a smaller annual consumption of elements and consequently the reduction of transport and replacement operations and of the storage pool systems as well as that of radioactive wastes; b) the saving of uranium and structural materials (Zircaloy and others). In the initial stage of program an homogeneous core enrichment of 0.85% by weight of U-235 is anticipated. The average discharge burnup of fuel elements, as estimated by previous studies, is approximately 11.6 MW d/kg U. The annual consumption of fuel elements is reduced from 396 of natural uranium to 205, with a load factor of 0.85. It is intended to reach the next equilibrium steps with an enrichment of 1.00 and 1.20% in U-235. (Author)

  16. Air strikes on uranium enrichment plants as potential sources of radioecological danger

    Directory of Open Access Journals (Sweden)

    Živanov Dragan

    2007-01-01

    Full Text Available According to the Non Proliferation Treaty (NPT, the signatory countries are not forbidden to preform uranium enrichment for peaceful purposes. However, if there is a justified doubt that the uranium enrichment is performed with the aim to produce nuclear weapons, this certainly causes great concern. In this case, the international community can apply pressure to a certain country if it determines that the country does not want to cease activities of making its own nuclear weapons. The international community pressure on the country can be intesified until its political leadership is not made to question and cease all activities of producing nuclear weapons. This pressure can be political, economic, and as a last resort-military. As a gesture of goodwill the country can stop the uranium enrichment process. In this way, the country shows that it finally gives up the intention to produce nuclear weapons. However, when military pressure is applied, i.e. military strikes (air strikes for example on nuclear plants used for uranium enrichment, this certainly creates a risk of releasing radioactivity into the environment. That is why the aim of this paper is to signal this very fact. Using military force in these cases leads to additional radioactive contamination of the environment, so this way of solving conflicts should be avoided within the international community.

  17. Enrichment of Gamma-Aminobutyric Acid in Bean Sprouts: Exploring Biosynthesis of Plant Metabolite Using Common Household Reagents

    Science.gov (United States)

    Rojanarata, Theerasak; Plianwong, Samarwadee; Opanasopit, Praneet; Ngawhirunpat, Tanasait

    2018-01-01

    The enrichment of plant foods with gamma-aminobutyric acid (GABA) is currently an interesting issue in the field of nutraceuticals and can be used as an experiment for upper-division undergraduate students. Here, an interdisciplinary hands-on experiment to produce GABA-enriched mung bean sprouts using common household reagents is described. Based…

  18. RADIO FREQUENCY IDENTIFICATION DEVICES: EFFECTIVENESS IN IMPROVING SAFEGUARDS AT GAS-CENTRIFUGE URANIUM-ENRICHMENT PLANTS

    International Nuclear Information System (INIS)

    JOE, J.

    2007-01-01

    Recent advances in radio frequency identification devices (RFIDs) have engendered a growing interest among international safeguards experts. Potentially, RFIDs could reduce inspection work, viz. the number of inspections, number of samples, and duration of the visits, and thus improve the efficiency and effectiveness of international safeguards. This study systematically examined the applications of RFIDs for IAEA safeguards at large gas-centrifuge enrichment plants (GCEPs). These analyses are expected to help identify the requirements and desirable properties for RFIDs, to provide insights into which vulnerabilities matter most, and help formulate the required assurance tests. This work, specifically assesses the application of RFIDs for the ''Option 4'' safeguards approach, proposed by Bruce Moran, U. S. Nuclear Regulatory Commission (NRC), for large gas-centrifuge uranium-enrichment plants. The features of ''Option 4'' safeguards include placing RFIDs on all feed, product and tails (F/P/T) cylinders, along with WID readers in all FP/T stations and accountability scales. Other features of Moran's ''Option 4'' are Mailbox declarations, monitoring of load-cell-based weighing systems at the F/P/T stations and accountability scales, and continuous enrichment monitors. Relevant diversion paths were explored to evaluate how RFIDs improve the efficiency and effectiveness of safeguards. Additionally, the analysis addresses the use of RFIDs in conjunction with video monitoring and neutron detectors in a perimeter-monitoring approach to show that RFIDs can help to detect unidentified cylinders

  19. Evaluation of two hybrid poplar clones as constructed wetland plant species for treating saline water high in boron and selenium, or waters only high in boron

    Science.gov (United States)

    Wetland mesocosms were constructed to assess two salt- and B-tolerant hybrid poplar clones (Populus trichocarpa ×P. deltoides×P. nigra '345-1' and '347-14') for treating saline water high in boron (B) and selenium (Se). In addition, a hydroponic experiment was performed to test the B tolerance and B...

  20. Enrichment of By-Product Materials from Steel Pickling Acid Regeneration Plants (TRP 9942)

    Energy Technology Data Exchange (ETDEWEB)

    Lu Swan, Delta Ferrites LLC

    2009-09-30

    A new process for manufacturing an enriched, iron-based product (strontium hexaferrite) in existing steel pickling acid regeneration facilities was evaluated. Process enhancements and equipment additions were made to an existing acid regeneration plant to develop and demonstrate (via pilot scale testing and partial-capacity production trials) the viability of a patented method to produce strontium-based compounds that, when mixed with steel pickling acid and roasted, would result in a strontium hexaferrite powder precursor which could then be subjected to further heat treatment in an atmosphere that promotes rapid, relatively low-temperature formation of discrete strontium hexaferrite magnetic domains yielding an enriched iron-based product, strontium hexaferrite, that can be used in manufacturing hard ferrite magnets.

  1. Subtle Gardeners: Inland Predators Enrich Local Topsoils and Enhance Plant Growth.

    Directory of Open Access Journals (Sweden)

    José M Fedriani

    Full Text Available Inland vertebrate predators could enrich of nutrients the local top soils in the area surrounding their nests and dens by depositing faeces, urine, and prey remains and, thus, alter the dynamics of plant populations. Surprisingly, and in contrast with convincing evidence from coastal habitats, whether and how this phenomenon occurs in inland habitats is largely uncertain even though these habitats represent a major fraction of the earth's surface. We investigated during two consecutive breeding seasons the potential enrichment of the top-soils associated with inland ground-nesting eagle owls Bubo bubo, as well as its possible consequences in the growth of two common annual grasses in southern Spain. Top-soils associated with owl nests differed strongly and significantly from control top-soils in chemical parameters, mainly fertility-related properties. Specifically, levels of available phosphorus, total nitrogen, organic matter, and available potassium were 49.1, 5.6, 3.1, and 2.7 times higher, respectively, in top-soils associated with owl nests as compared to control top-soils. Germination experiments in chambers indicated that nutrient enrichment by nesting owls enhanced seedling growth in both annual grasses (Phalaris canariensis and Avena sativa, with seedling size being 1.4-1.3 times higher in owl nest top-soils than in control top-soils. Our experimental study revealed that pervasive inland, predatory birds can profoundly enrich the topsoil around their nests and, thus, potentially enhance local vegetation growth. Because diverse inland vertebrate predators are widespread in most habitats they have a strong potential to enhance spatial heterogeneity, impinge on plant communities, and exert an overlooked effect on primary productivity worldwide.

  2. Assessment of phosphopeptide enrichment/precipitation method for LC-MS/MS based phosphoproteomic analysis of plant tissue

    DEFF Research Database (Denmark)

    Ye, Juanying; Rudashevskaya, Elena; Hansen, Thomas Aarup

    selectivity. The overlap between the 3 enrichment experiments was quite small. We are currently investigating further combination of enrichment methods: SIMAC enrichment and the combination of CPP and IMAC enrichment. Samples will be analyzed by LTQ-Orbitrap-ETD MS, and the behavior of phosphopeptides on CID...... is necessary. At present, numerous phosphopeptide enrichment approaches have been established and applied to complex biological samples. We and others have reported that multi-step phosphopeptide purification methods enable better recovery of phosphopeptide and achieve higher selectivity and sensitivity than...... stardand sample preparation protocols. Here, we combine 3 phosphpeptide enrichment methods (IMAC, TiO2 and Calcium Phosphate Precipitation (CPP)), and apply them to phosphoproteomic analysis of Arabidopsis thaliana plasma membrane preparation. Method Plant plasma membranes were isolated from Arabidopsis...

  3. Hyb-Seq: Combining Target Enrichment and Genome Skimming for Plant Phylogenomics

    Directory of Open Access Journals (Sweden)

    Kevin Weitemier

    2014-08-01

    Full Text Available Premise of the study: Hyb-Seq, the combination of target enrichment and genome skimming, allows simultaneous data collection for low-copy nuclear genes and high-copy genomic targets for plant systematics and evolution studies. Methods and Results: Genome and transcriptome assemblies for milkweed (Asclepias syriaca were used to design enrichment probes for 3385 exons from 768 genes (>1.6 Mbp followed by Illumina sequencing of enriched libraries. Hyb-Seq of 12 individuals (10 Asclepias species and two related genera resulted in at least partial assembly of 92.6% of exons and 99.7% of genes and an average assembly length >2 Mbp. Importantly, complete plastomes and nuclear ribosomal DNA cistrons were assembled using off-target reads. Phylogenomic analyses demonstrated signal conflict between genomes. Conclusions: The Hyb-Seq approach enables targeted sequencing of thousands of low-copy nuclear exons and flanking regions, as well as genome skimming of high-copy repeats and organellar genomes, to efficiently produce genome-scale data sets for phylogenomics.

  4. Approach to IAEA material-balance verification at the Portsmouth Gas Centrifuge Enrichment Plant

    International Nuclear Information System (INIS)

    Gordon, D.M.; Sanborn, J.B.; Younkin, J.M.; DeVito, V.J.

    1983-01-01

    This paper describes a potential approach by which the International Atomic Energy Agency (IAEA) might verify the nuclear-material balance at the Portsmouth Gas Centrifuge Enrichment Plant (GCEP). The strategy makes use of the attributes and variables measurement verification approach, whereby the IAEA would perform independent measurements on a randomly selected subset of the items comprising the U-235 flows and inventories at the plant. In addition, the MUF-D statistic is used as the test statistic for the detection of diversion. The paper includes descriptions of the potential verification activities, as well as calculations of: (1) attributes and variables sample sizes for the various strata, (2) standard deviations of the relevant test statistics, and (3) the detection sensitivity which the IAEA might achieve by this verification strategy at GCEP

  5. Using Process Load Cell Information for IAEA Safeguards at Enrichment Plants

    International Nuclear Information System (INIS)

    Laughter, Mark D.; Whitaker, J. Michael; Howell, John

    2010-01-01

    Uranium enrichment service providers are expanding existing enrichment plants and constructing new facilities to meet demands resulting from the shutdown of gaseous diffusion plants, the completion of the U.S.-Russia highly enriched uranium downblending program, and the projected global renaissance in nuclear power. The International Atomic Energy Agency (IAEA) conducts verification inspections at safeguarded facilities to provide assurance that signatory States comply with their treaty obligations to use nuclear materials only for peaceful purposes. Continuous, unattended monitoring of load cells in UF 6 feed/withdrawal stations can provide safeguards-relevant process information to make existing safeguards approaches more efficient and effective and enable novel safeguards concepts such as information-driven inspections. The IAEA has indicated that process load cell monitoring will play a central role in future safeguards approaches for large-scale gas centrifuge enrichment plants. This presentation will discuss previous work and future plans related to continuous load cell monitoring, including: (1) algorithms for automated analysis of load cell data, including filtering methods to determine significant weights and eliminate irrelevant impulses; (2) development of metrics for declaration verification and off-normal operation detection ('cylinder counting,' near-real-time mass balancing, F/P/T ratios, etc.); (3) requirements to specify what potentially sensitive data is safeguards relevant, at what point the IAEA gains on-site custody of the data, and what portion of that data can be transmitted off-site; (4) authentication, secure on-site storage, and secure transmission of load cell data; (5) data processing and remote monitoring schemes to control access to sensitive and proprietary information; (6) integration of process load cell data in a layered safeguards approach with cross-check verification; (7) process mock-ups constructed to provide simulated load

  6. The enrichment behavior of natural radionuclides in pulverized oil shale-fired power plants

    International Nuclear Information System (INIS)

    Vaasma, Taavi; Kiisk, Madis; Meriste, Tõnis; Tkaczyk, Alan Henry

    2014-01-01

    The oil shale industry is the largest producer of NORM (Naturally Occurring Radioactive Material) waste in Estonia. Approximately 11–12 million tons of oil shale containing various amounts of natural radionuclides is burned annually in the Narva oil shale-fired power plants, which accounts for approximately 90% of Estonian electricity production. The radionuclide behavior characteristics change during the fuel combustion process, which redistributes the radionuclides between different ash fractions. Out of 24 operational boilers in the power plants, four use circulating fluidized bed (CFB) technology and twenty use pulverized fuel (PF) technology. Over the past decade, the PF boilers have been renovated, with the main objective to increase the efficiency of the filter systems. Between 2009 and 2012, electrostatic precipitators (ESP) in four PF energy blocks were replaced with novel integrated desulphurization technology (NID) for the efficient removal of fly ash and SO 2 from flue gases. Using gamma spectrometry, activity concentrations and enrichment factors for the 238 U ( 238 U, 226 Ra, 210 Pb) and 232 Th ( 232 Th, 228 Ra) family radionuclides as well as 40 K were measured and analyzed in different PF boiler ash fractions. The radionuclide activity concentrations in the ash samples increased from the furnace toward the back end of the flue gas duct. The highest values in different PF boiler ash fractions were in the last field of the ESP and in the NID ash, where radionuclide enrichment factors were up to 4.2 and 3.3, respectively. The acquired and analyzed data on radionuclide activity concentrations in different PF boiler ashes (operating with an ESP and a NID system) compared to CFB boiler ashes provides an indication that changes in the fuel (oil shale) composition and boiler working parameters, as well as technological enhancements in Estonian oil shale fired power plants, have had a combined effect on the distribution patterns of natural radionuclides in

  7. Resolving phylogenetic relationships of the recently radiated carnivorous plant genus Sarracenia using target enrichment.

    Science.gov (United States)

    Stephens, Jessica D; Rogers, Willie L; Heyduk, Karolina; Cruse-Sanders, Jennifer M; Determann, Ron O; Glenn, Travis C; Malmberg, Russell L

    2015-04-01

    The North American carnivorous pitcher plant genus Sarracenia (Sarraceniaceae) is a relatively young clade (carnivorous plants; however, little is known regarding evolutionary relationships within the genus. Previous attempts at resolving the phylogeny have been unsuccessful, most likely due to few parsimony-informative sites compounded by incomplete lineage sorting. Here, we applied a target enrichment approach using multiple accessions to assess the relationships of Sarracenia species. This resulted in 199 nuclear genes from 75 accessions covering the putative 8-11 species and 8 subspecies/varieties. In addition, we recovered 42kb of plastome sequence from each accession to estimate a cpDNA-derived phylogeny. Unsurprisingly, the cpDNA had few parsimony-informative sites (0.5%) and provided little information on species relationships. In contrast, use of the targeted nuclear loci in concatenation and coalescent frameworks elucidated many relationships within Sarracenia even with high heterogeneity among gene trees. Results were largely consistent for both concatenation and coalescent approaches. The only major disagreement was with the placement of the purpurea complex. Moreover, results suggest an Appalachian massif biogeographic origin of the genus. Overall, this study highlights the utility of target enrichment using multiple accessions to resolve relationships in recently radiated taxa. Copyright © 2015 Elsevier Inc. All rights reserved.

  8. Boron isotopes and groundwater pollution

    International Nuclear Information System (INIS)

    Vengosh, A.

    1999-01-01

    Boron can be used as a tracer in ground water because of its high solubility in aqueous solutions, natural abundance in all waters, and the lack of effects by evaporation, volatilisation, oxidation-reduction reactions. Since the boron concentrations in pristine ground waters are generally low and contaminant sources are usually enriched in boron, the δ 11 B of groundwater is highly sensitive to the impact of contamination. The large isotopic variations of the potential sources can be used to trace the origin of the contamination and to reconstruct mixing and flow paths

  9. Enhanced binding capacity of boronate affinity adsorbent via surface modification of silica by combination of atom transfer radical polymerization and chain-end functionalization for high-efficiency enrichment of cis-diol molecules

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Wei; He, Maofang; Wang, Chaozhan; Wei, Yinmao, E-mail: ymwei@nwu.edu.cn

    2015-07-30

    Boronate affinity materials have been widely used for specific separation and preconcentration of cis-diol molecules, but most do not have sufficient capacity due to limited binding sites on the material surface. In this work, we prepared a phenylboronic acid-functionalized adsorbent with a high binding capacity via the combination of surface-initiated atom transfer radical polymerization (SI-ATRP) and chain-end functionalization. With this method, the terminal chlorides of the polymer chains were used fully, and the proposed adsorbent contains dense boronic acid polymers chain with boronic acid on the chain end. Consequently, the proposed adsorbent possesses excellent selectivity and a high binding capacity of 513.6 μmol g{sup −1} for catechol and 736.8 μmol g{sup −1} for fructose, which are much higher than those of other reported adsorbents. The dispersed solid-phase extraction (dSPE) based on the prepared adsorbent was used for extraction of three cis-diol drugs (i.e., epinephrine, isoprenaline and caffeic acid isopropyl ester) from plasma; the eluates were analyzed by HPLC-UV. The reduced amount of adsorbent (i.e., 2.0 mg) could still eliminate interferences efficiently and yielded a recovery range of 85.6–101.1% with relative standard deviations ranging from 2.5 to 9.7% (n = 5). The results indicated that the proposed strategy could serve as a promising alternative to increase the density of surface functional groups on the adsorbent; thus, the prepared adsorbent has the potential to effectively enrich cis-diol substances in real samples. - Highlights: • Boronate adsorbent is prepared via ATRP and chain-end functionalization. • The adsorbent has quite high binding capacity for cis-diols. • Binding capacity is easily manipulated by ATRP condition. • Chain-end functionalization can improve binding capacity significantly. • Reduced adsorbent is consumed in dispersed solid-phase extraction of cis-diols.

  10. The role of calcium, silicon and salicylic acid treatment in protection of canola plants against boron toxicity stress.

    Science.gov (United States)

    Metwally, Ashraf M; Radi, Abeer A; El-Shazoly, Rasha M; Hamada, Afaf M

    2018-01-22

    Boron (B) toxicity often limits crop yield and the quality of production in agricultural areas. Here, we investigated the effects of calcium (Ca), silicon (Si) and salicylic acid (SA) on development of B toxicity, B allocation in canola (Brassica napus cultivar Sarw 4) and its role in non-enzymatic antioxidants in relation to yield of this cultivar under B toxicity. Canola seedlings were subjected to four B levels induced by boric acid in the absence or presence of Ca, Si and SA. The results showed that Ca, Si and SA addition ameliorated the inhibition in canola growth, water content (WC), and improved siliqua number, siliqua weight and seed index. The B content in shoots and roots and total B accumulation in the whole plant were increased in control plants under B-toxicity-stress, and these parameters were significantly decreased by addition of Ca, Si and SA. The shoot ascorbate pool (ascorbate, AsA, and dehydroascorbate, DHA), α-tocopherol and phenolics (free and bound) were increased under B toxicity, and were significantly decreased in most cases by addition of Ca, Si and SA, except α-tocopherol, which increased at low B levels (0, 25 and 50 mg kg soil -1 ). The glutathione content did not obviously change by B stress, while added Ca, Si and SA inhibited its accumulation under B stress. In addition, B toxicity reduced the shoot flavonoids content; however, this reduction was not alleviated by the use of Ca, Si and SA treatments. It could be concluded that growth and yield of canola plants grown under high B concentration improved after external application of Ca, Si or SA.

  11. CO2 enrichment accelerates successional development of an understory plant community

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Lara [University of Tennessee, Knoxville (UTK); Belote, R. Travis Travis [Wilderness Society, The; Kardol, Paul [ORNL; Weltzin, Jake [ORNL; Norby, Richard J [ORNL

    2010-01-01

    Rising concentrations of atmospheric carbon dioxide ([CO{sub 2}]) may influence forest successional development and species composition of understory plant communities by altering biomass production of plant species of functional groups. Here, we describe how elevated [CO{sub 2}] (eCO{sub 2}) affects aboveground biomass within the understory community of a temperate deciduous forest at the Oak Ridge National Laboratory sweetgum (Liquidambar styraciflua) free-air carbon dioxide enrichment (FACE) facility in eastern Tennessee, USA. We asked if (i) CO{sub 2} enrichment affected total understory biomass and (ii) whether total biomass responses could be explained by changes in understory species composition or changes in relative abundance of functional groups through time. The FACE experiment started in 1998 with three rings receiving ambient [CO{sub 2}] (aCO{sub 2}) and two rings receiving eCO{sub 2}. From 2001 to 2003, we estimated species-specific, woody versus herbaceous and total aboveground biomass by harvesting four 1 x 0.5-m subplots within the established understory plant community in each FACE plot. In 2008, we estimated herbaceous biomass as previously but used allometric relationships to estimate woody biomass across two 5 x 5-m quadrats in each FACE plot. Across years, aboveground biomass of the understory community was on average 25% greater in eCO{sub 2} than in aCO{sub 2} plots. We could not detect differences in plant species composition between aCO{sub 2} and eCO{sub 2} treatments. However, we did observe shifts in the relative abundance of plant functional groups, which reflect important structural changes in the understory community. In 2001-03, little of the understory biomass was in woody species; herbaceous species made up 94% of the total understory biomass across [CO{sub 2}] treatments. Through time, woody species increased in importance, mostly in eCO{sub 2}, and in 2008, the contribution of herbaceous species to total understory biomass was

  12. Laboratory demonstration of a multi-sensor unattended cylinder verification station for uranium enrichment plant safeguards

    Energy Technology Data Exchange (ETDEWEB)

    Goodman, David I [Univ. of Michigan, Ann Arbor, MI (United States); Rowland, Kelly L [Univ. of California, Berkeley, CA (United States); Smith, Sheriden [Colorado State Univ., Fort Collins, CO (United States); Miller, Karen A. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Flynn, Eric B. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2014-01-10

    The objective of safeguards is the timely detection of the diversion of a significant quantity of nuclear materials, and safeguarding uranium enrichment plants is especially important in preventing the spread of nuclear weapons. The IAEA’s proposed Unattended Cylinder Verification Station (UCVS) for UF6 cylinder verification would combine the operator’s accountancy scale with a nondestructive assay system such as the Passive Neutron Enrichment Meter (PNEM) and cylinder identification and surveillance systems. In this project, we built a laboratory-scale UCVS and demonstrated its capabilities using mock UF6 cylinders. We developed a signal processing algorithm to automate the data collection and processing from four continuous, unattended sensors. The laboratory demonstration of the system showed that the software could successfully identify cylinders, snip sensor data at the appropriate points in time, determine the relevant characteristics of the cylinder contents, check for consistency among sensors, and output the cylinder data to a file. This paper describes the equipment, algorithm and software development, laboratory demonstration, and recommendations for a full-scale UCVS.

  13. Issues and recommendations related to replacement of CFC-114 at the uranium enrichment gaseous diffusion plant

    International Nuclear Information System (INIS)

    Anderson, B.L.; Banaghan, E.

    1993-01-01

    The operating uranium enrichment gaseous diffusion plants (GDPs) in Portsmouth, Ohio and Paducah, Kentucky, which are operated for the United States Department for Energy by Martin Marietta Energy Systems (MMES), currently use a chlorofluorocarbon (CFC-114) as the primary process stream coolant. Due to recent legislation embodied in the Clean Air Act, the production of this and other related chlorofluorocarbons (CFCS) are to be phased out with no production occurring after 1995. Since the plants lose approximately 500,000 pounds per year of this process stream coolant through various leaks, the GDPs are faced with the challenge of identifying a replacement coolant that will allow continued operation of the plants. MMES formed the CFC Task Team to identify and solve the various problems associated with identifying and implementing a replacement coolant. This report includes a review of the work performed by the CFC Task Team, and recommendations that were formulated based on this review and upon original work. The topics covered include; identifying a replacement coolant, coolant leak detection and repair efforts, coolant safety concerns, coolant level sensors, regulatory issues, and an analytical decision analysis

  14. Procedures for the retention of gaseous tritium released from a tritium enrichment plant

    International Nuclear Information System (INIS)

    Gutowski, H.; Bracha, M.

    1987-01-01

    General aim of the study is the comparison of two alternative processes for the retention of gaseous tritium which is released during normal operation and emergency operation in a tritium-enrichment-plant. Two processes for the retention of tritium were compared: 1. Oxidation-process. The hydrogen-gas containing HT will be burnt on an oxidation catalyst to H 2 O and HTO. In a subsequent step the water will be removed from the process by condensation, freezing and adsorption. 2. TROC-process (Tritium Removal by Organic Compounds). The tritium is added to an organic compound (acid) via catalyst. This reaction is irreversible and leads to solid products. (orig./RB) [de

  15. Optimization and Comparative Analysis of Plant Organellar DNA Enrichment Methods Suitable for Next-generation Sequencing.

    Science.gov (United States)

    Miller, Marisa E; Liberatore, Katie L; Kianian, Shahryar F

    2017-07-28

    Plant organellar genomes contain large, repetitive elements that may undergo pairing or recombination to form complex structures and/or sub-genomic fragments. Organellar genomes also exist in admixtures within a given cell or tissue type (heteroplasmy), and an abundance of subtypes may change throughout development or when under stress (sub-stoichiometric shifting). Next-generation sequencing (NGS) technologies are required to obtain deeper understanding of organellar genome structure and function. Traditional sequencing studies use several methods to obtain organellar DNA: (1) If a large amount of starting tissue is used, it is homogenized and subjected to differential centrifugation and/or gradient purification. (2) If a smaller amount of tissue is used (i.e., if seeds, material, or space is limited), the same process is performed as in (1), followed by whole-genome amplification to obtain sufficient DNA. (3) Bioinformatics analysis can be used to sequence the total genomic DNA and to parse out organellar reads. All these methods have inherent challenges and tradeoffs. In (1), it may be difficult to obtain such a large amount of starting tissue; in (2), whole-genome amplification could introduce a sequencing bias; and in (3), homology between nuclear and organellar genomes could interfere with assembly and analysis. In plants with large nuclear genomes, it is advantageous to enrich for organellar DNA to reduce sequencing costs and sequence complexity for bioinformatics analyses. Here, we compare a traditional differential centrifugation method with a fourth method, an adapted CpG-methyl pulldown approach, to separate the total genomic DNA into nuclear and organellar fractions. Both methods yield sufficient DNA for NGS, DNA that is highly enriched for organellar sequences, albeit at different ratios in mitochondria and chloroplasts. We present the optimization of these methods for wheat leaf tissue and discuss major advantages and disadvantages of each approach in

  16. On-Line Enrichment Monitor (OLEM) Phase II Final Report Techniques and Equipment for Safeguards at Gas Centrifuge Enrichment Plants

    Energy Technology Data Exchange (ETDEWEB)

    Younkin, James R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Garner, James R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2017-04-01

    Over the last five years, OLEM has been a collaborative development effort involving the IAEA, LANL, ORNL, URENCO, and the NNSA. The collective team has completed the following: design and modelling, software development, hardware integration, testing with the ORNL UF6 Flow Loop, a field trial at the Urenco facility in Almelo, the Netherlands, and a Demonstration at the Urenco USA facility in Eunice, New Mexico. This combined effort culminated in the deployment of several OLEM collection nodes in Iran. These OLEM units are one unattended monitoring system component of the Joint Comprehensive Plan of Action allowing the International Atomic Energy Agency to verify Iran’s compliance with the enrichment production aspects of the agreement.

  17. Effects of a Plant Sterol or Stanol Enriched Mixed Meal on Postprandial Lipid Metabolism in Healthy Subjects.

    Science.gov (United States)

    Baumgartner, Sabine; Mensink, Ronald P; Plat, Jogchum

    2016-01-01

    Evidence is increasing that plant sterols and stanols not only lower fasting serum low-density lipoprotein concentrations, but also those of triglycerides (TG). Insight into effects of these components on postprandial TG metabolism, an emerging risk factor for cardiovascular disease, is missing. Our objective was to examine the 8-hour postprandial response after consuming plant sterol or stanol enriched margarine as part of a mixed meal. This postprandial study was part of a randomized crossover study in which 42 subjects consumed plant sterol enriched (3 g/d plant sterols), plant stanol enriched (3 g/d plant stanols), and control margarines for 4 weeks. After each period, subjects consumed a shake enriched with 3g plant sterols (sterol period), 3g plant stanols (stanol period) or no addition (control period). Subjects received a second shake with no addition after 4 hours. TG and apoB48 incremental areas under the curves (iAUC) of the total (0-8h) and 1st meal response (0-4h) were comparable between the meals and in all age categories (I:18-35y, II:36-52y, III:53-69y). In subjects aged 53-69y, TG iAUC after the 2nd meal (4-8h) was higher in the stanol period as compared with the sterol (63.1±53.0 mmol/L/min; P postprandial responses may be due to reduced lipoprotein lipase activity, since postprandial apoCIII/II ratios were increased after stanol consumption compared with the control meal. Postprandial TG and apoB48 responses are age-dependently increased after plant stanol consumption, which might be related to a changed clearance of triglyceride-rich lipoproteins. ClinicalTrials.gov NCT01559428.

  18. Grazing damage to plants and gastropod and grasshopper densities in a CO 2-enrichment experiment on calcareous grassland

    Science.gov (United States)

    Ledergerber, Stephan; Thommen, G. Heinrich; Baur, Bruno

    Plant-herbivore interactions may change as atmospheric CO 2 concentrations continue to rise. We examined the effects of elevated atmospheric CO 2 and CO 2-exposure chambers on the grazing damage to plants, and on the abundances of potential herbivores (terrestrial gastropods and grasshoppers) in a calcareous grassland in the Jura mountains of Switzerland (village of Nenzlingen). Individuals of most plant species examined showed slight grazing damage. However, plots with CO 2 enrichment and plots with ambient atmosphere did not differ in the extent of grazing damage. Similarly, plots with CO 2 enrichment and plots with ambient atmosphere did not differ in either gastropod or grasshopper density. Experimental plots with and without chambers did not differ in the number of gastropods. However, the densities of gastropods and grasshoppers and extent of grazing damage to plants were generally lower in the experimental area than in the grassland outside the experimental field.

  19. Cholesterol lowering effect of a soy drink enriched with plant sterols in a French population with moderate hypercholesterolemia

    Directory of Open Access Journals (Sweden)

    Bard Jean-Marie

    2008-10-01

    Full Text Available Abstract Background Plant sterols are an established non-pharmacological means to reduce total and LDL blood cholesterol concentrations and are therefore recommended for cholesterol management by worldwide-renown health care institutions. Their efficacy has been proven in many types of foods with the majority of trials conducted in spreads or dairy products. As an alternative to dairy products, soy based foods are common throughout the world. Yet, there is little evidence supporting the efficacy of plant sterols in soy-based foods. The objective of this study was to investigate the effect of a soy drink enriched with plant sterols on blood lipid profiles in moderately hypercholesterolemic subjects. Methods In a randomized, placebo-controlled double-blind mono-centric study, 50 subjects were assigned to 200 ml of soy drink either enriched with 2.6 g plant sterol esters (1.6 g/d free plant sterol equivalents or without plant sterols (control for 8 weeks. Subjects were instructed to maintain stable diet pattern and physical activity. Plasma concentrations of lipids were measured at initial visit, after 4 weeks and after 8 weeks. The primary measurement was the change in LDL cholesterol (LDL-C. Secondary measurements were changes in total cholesterol (TC, non-HDL cholesterol (non-HDL-C, HDL cholesterol (HDL-C and triglycerides. Results Regular consumption of the soy drink enriched with plant sterols for 8 weeks significantly reduced LDL- C by 0.29 mmol/l or 7% compared to baseline (p 96%, and products were well tolerated. Conclusion Daily consumption of a plant sterol-enriched soy drink significantly decreased total, non-HDL and LDL cholesterol and is therefore an interesting and convenient aid in managing mild to moderate hypercholesterolemia.

  20. Containment and storage of uranium hexafluoride at US Department of Energy uranium enrichment plants

    Energy Technology Data Exchange (ETDEWEB)

    Barlow, C.R.; Alderson, J.H.; Blue, S.C.; Boelens, R.A.; Conkel, M.E.; Dorning, R.E.; Ecklund, C.D.; Halicks, W.G.; Henson, H.M.; Newman, V.S.; Philpot, H.E.; Taylor, M.S.; Vournazos, J.P. [Oak Ridge K-25 Site, TN (United States). UEO Enrichment Technical Operations Div.; Russell, J.R. [USDOE Oak Ridge Field Office, TN (United States); Pryor, W.A. [PAI Corp., Oak Ridge, TN (United States); Ziehlke, K.T. [MJB Technical Associates (United States)

    1992-07-01

    Isotopically depleted UF{sub 6} (uranium hexafluoride) accumulates at a rate five to ten times greater than the enriched product and is stored in steel vessels at the enrichment plant sites. There are approximately 55,000 large cylinders now in storage at Paducah, Kentucky; Portsmouth, Ohio; and Oak Ridge, Tennessee. Most of them contain a nominal 14 tons of depleted UF{sub 6}. Some of these cylinders have been in the unprotected outdoor storage environment for periods approaching 40 years. Storage experience, supplemented by limited corrosion data, suggests a service life of about 70 years under optimum conditions for the 48-in. diameter, 5/16-in.-wall pressure vessels (100 psi working pressure), using a conservative industry-established 1/4-in.-wall thickness as the service limit. In the past few years, however, factors other than atmospheric corrosion have become apparent that adversely affect the serviceability of small numbers of the storage containers and that indicate the need for a managed program to ensure maintenance ofcontainment integrity for all the cylinders in storage. The program includes periodic visual inspections of cylinders and storage yards with documentation for comparison with other inspections, a group of corrosion test programs to permit cylinder life forecasts, and identification of (and scheduling for remedial action) situations in which defects, due to handling damage or accelerated corrosion, can seriously shorten the storage life or compromise the containment integrity of individual cylinders. The program also includes rupture testing to assess the effects of certain classes of damage on overall cylinder strength, aswell as ongoing reviews of specifications, procedures, practices, and inspection results to effect improvements in handling safety, containment integrity, and storage life.

  1. Containment and storage of uranium hexafluoride at US Department of Energy uranium enrichment plants

    International Nuclear Information System (INIS)

    Barlow, C.R.; Alderson, J.H.; Blue, S.C.; Boelens, R.A.; Conkel, M.E.; Dorning, R.E.; Ecklund, C.D.; Halicks, W.G.; Henson, H.M.; Newman, V.S.; Philpot, H.E.; Taylor, M.S.; Vournazos, J.P.; Pryor, W.A.; Ziehlke, K.T.

    1992-07-01

    Isotopically depleted UF 6 (uranium hexafluoride) accumulates at a rate five to ten times greater than the enriched product and is stored in steel vessels at the enrichment plant sites. There are approximately 55,000 large cylinders now in storage at Paducah, Kentucky; Portsmouth, Ohio; and Oak Ridge, Tennessee. Most of them contain a nominal 14 tons of depleted UF 6 . Some of these cylinders have been in the unprotected outdoor storage environment for periods approaching 40 years. Storage experience, supplemented by limited corrosion data, suggests a service life of about 70 years under optimum conditions for the 48-in. diameter, 5/16-in.-wall pressure vessels (100 psi working pressure), using a conservative industry-established 1/4-in.-wall thickness as the service limit. In the past few years, however, factors other than atmospheric corrosion have become apparent that adversely affect the serviceability of small numbers of the storage containers and that indicate the need for a managed program to ensure maintenance ofcontainment integrity for all the cylinders in storage. The program includes periodic visual inspections of cylinders and storage yards with documentation for comparison with other inspections, a group of corrosion test programs to permit cylinder life forecasts, and identification of (and scheduling for remedial action) situations in which defects, due to handling damage or accelerated corrosion, can seriously shorten the storage life or compromise the containment integrity of individual cylinders. The program also includes rupture testing to assess the effects of certain classes of damage on overall cylinder strength, aswell as ongoing reviews of specifications, procedures, practices, and inspection results to effect improvements in handling safety, containment integrity, and storage life

  2. 10 CFR Appendix H to Part 110 - Illustrative List of Electromagnetic Enrichment Plant Equipment and Components Under NRC Export...

    Science.gov (United States)

    2010-01-01

    ... Equipment and Components Under NRC Export Licensing Authority H Appendix H to Part 110 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) EXPORT AND IMPORT OF NUCLEAR EQUIPMENT AND MATERIAL Pt. 110, App. H Appendix H to Part 110—Illustrative List of Electromagnetic Enrichment Plant Equipment and Components Under...

  3. 10 CFR Appendix G to Part 110 - Illustrative List of Plasma Separation Enrichment Plant Equipment and Components Under NRC Export...

    Science.gov (United States)

    2010-01-01

    ... Equipment and Components Under NRC Export Licensing Authority G Appendix G to Part 110 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) EXPORT AND IMPORT OF NUCLEAR EQUIPMENT AND MATERIAL Pt. 110, App. G Appendix G to Part 110—Illustrative List of Plasma Separation Enrichment Plant Equipment and Components...

  4. Boron nutrition and yield of alfalfa cultivar crioula in relation to boron supply

    Directory of Open Access Journals (Sweden)

    Santos Anacleto Ranulfo dos

    2004-01-01

    Full Text Available Alfalfa cultivar Crioula (Medicago sativa cv. Crioula is grown in South Brazil and only a few studies on the plants' boron requirement are available. A greenhouse experiment was carried out with alfalfa to measure boron acquisition, production and distribution in the plant; data on critical level and production potentials were recorded. Plants were grown in ground quartz added with 1 L of solution, with the following boron rates: 0, 0.0625, 0.125, 0.25, 0.50, 1.00, and 2.00 mg L-1. Plants were harvested at 46 days of growth. Forage dry mass was increased by boron supply and dry matter accumulation was considerably low in control. Boron concentration in the leaves was higher than in the stems or roots. Boron utilization from the external solution reached 90% at 0.0625 mg L-1 and sharply decreased with further increasing boron rates. Boron concentration and content in the leaves and in plant tops were at maximum when applied boron was between 1.5 and 1.6 mg L-1. Critical levels of boron in plant were 61 mg kg-1 in the leaves and 39 mg kg-1 in plant tops for this cultivar of alfalfa.

  5. Boron Isotope Fractionation in Bell Pepper

    OpenAIRE

    Geilert, Sonja; Vogl, Jochen; Rosner, Martin; Voerkelius, Susanne; Eichert, Thomas

    2015-01-01

    Various plant compartments of a single bell pepper plant were studied to verify the variability of boron isotope composition in plants and to identify possible intra-plant isotope fractionation. Boron mass fractions varied from 9.8 mg/kg in the fruits to 70.0 mg/kg in the leaves. Boron (B) isotope ratios reported as δ11B ranged from -11.0‰ to +16.0‰ (U ≤ 1.9‰, k=2) and showed a distinct trend to heavier δ11B values the higher the plant compartments were located in the plant. A fractionatio...

  6. Method of separating boron isotopes

    Science.gov (United States)

    Jensen, Reed J.; Thorne, James M.; Cluff, Coran L.; Hayes, John K.

    1984-01-01

    A method of boron isotope enrichment involving the isotope preferential photolysis of (2-chloroethenyl)dichloroborane as the feed material. The photolysis can readily be achieved with CO.sub.2 laser radiation and using fluences significantly below those required to dissociate BCl.sub.3.

  7. Solid sampling-graphite furnace atomic absorption spectrometry for the direct determination of boron in plant tissues

    International Nuclear Information System (INIS)

    Resano, M.; Briceno, J.; Aramendia, M.; Belarra, M.A.

    2007-01-01

    In this work, the potential of graphite furnace atomic absorption spectrometry for the direct determination of B in plant tissues has been investigated. Three certified reference materials (NIST SRM 1570a spinach leaves, NIST SRM 1573a tomato leaves and BCR CRM 679 white cabbage) were selected for this study, the goal always being to develop a fast procedure that could be robust enough to provide a satisfactory performance for all of them, without any modifications in the conditions applied. The use of a suitable chemical modifier was found to be essential for obtaining a reproducible and sufficiently sensitive signal for boron solutions. In this regard, the performance of the combination of citric acid plus W (added as a permanent modifier) was noteworthy, resulting in well-defined signal profiles, a remarkable analyte stabilization during the pyrolysis step (up to 2100 deg. C) and minimal memory effects. This mixture of modifiers provided a good performance for the direct analysis of solid samples as well, but only if a suitable temperature program, favoring the interaction between the analyte and the modifiers, was used. Thus, such a temperature program, with two pyrolysis steps and the addition of NH 4 NO 3 in order to carry out the in situ sample microdigestion, was optimized. Under these conditions, the peak areas obtained for both solid samples and aqueous standards were comparable. Finally, the analysis of the samples was carried out. In all cases, a good agreement with the certified values was obtained, while R.S.D. values ranged between 6 and 10%. It can be concluded that the method proposed shows significant advantages for the determination of this complicated element in solid samples such as the use of aqueous standards for calibration, a high sample throughput (20 min per sample), a suitable limit of detection (0.3 μg g -1 ) and reduced risk of analyte losses and contamination

  8. Plant and arthropod community sensitivity to rainfall manipulation but not nitrogen enrichment in a successional grassland ecosystem.

    Science.gov (United States)

    Lee, Mark A; Manning, Pete; Walker, Catherine S; Power, Sally A

    2014-12-01

    Grasslands provide many ecosystem services including carbon storage, biodiversity preservation and livestock forage production. These ecosystem services will change in the future in response to multiple global environmental changes, including climate change and increased nitrogen inputs. We conducted an experimental study over 3 years in a mesotrophic grassland ecosystem in southern England. We aimed to expose plots to rainfall manipulation that simulated IPCC 4th Assessment projections for 2100 (+15% winter rainfall and -30% summer rainfall) or ambient climate, achieving +15% winter rainfall and -39% summer rainfall in rainfall-manipulated plots. Nitrogen (40 kg ha(-1) year(-1)) was also added to half of the experimental plots in factorial combination. Plant species composition and above ground biomass were not affected by rainfall in the first 2 years and the plant community did not respond to nitrogen enrichment throughout the experiment. In the third year, above-ground plant biomass declined in rainfall-manipulated plots, driven by a decline in the abundances of grass species characteristic of moist soils. Declining plant biomass was also associated with changes to arthropod communities, with lower abundances of plant-feeding Auchenorrhyncha and carnivorous Araneae indicating multi-trophic responses to rainfall manipulation. Plant and arthropod community composition and plant biomass responses to rainfall manipulation were not modified by nitrogen enrichment, which was not expected, but may have resulted from prior nitrogen saturation and/or phosphorus limitation. Overall, our study demonstrates that climate change may in future influence plant productivity and induce multi-trophic responses in grasslands.

  9. The ecological risk assessment of heavy metals in the Kuihe River basin (Xuzhou section) and the characteristics of plant enrichment

    Science.gov (United States)

    Sun, Ling; Zheng, Lei

    2018-01-01

    In order to investigate Kuihe River basin of heavy metals (As, Cd, Cr, Cu, Mn, Ni, Pb and Zn) pollution, the determination of the Kuihe River water body, the bottom of the river silt, riparian soil plants and heavy metal content of 9 kinds of riparian plants, investigate the pollution situation, so as to screen out the plants that has potential of enrichment and rehabilitation of heavy metal pollution. The results showed that Cd and Mn in the water body exceed bid; The pollution of Zn and Cu in the bottom mud is serious, potential ecological risk of heavy metals is Zn>Cu>Pb>Ni>Cd>As>Cr>Mn Riparian soil affected by sewage and overflow of sediment has significant positive correlation with soil heavy metals, among them, the Zn and Cu are heavy pollution; The selective absorption of heavy metals by 9 kinds of dominant plant leads to its bio concentration factor (BCF) of Cr and Pb on the low side, are all less than 1, from the translocation factor (TF), Setcreasea purpurea and Poa annua showed obvious roots type hoarding. Poa annua and Lycium chinense have a resistance on the absorption of heavy metals, Lythrum salicaria, Photinia serrulata and Broussonetia papyrifera have a unique advantage on enrichment of heavy metals, Broussonetia papyri era on a variety of strong ability of enrichment and transfer of heavy metals suggests that the woody plants in the vast application prospect in the field of rehabilitation technology of heavy metals.

  10. Chronic N enrichment and drought alter plant cover and community composition in a Mediterranean-type semi-arid shrubland.

    Science.gov (United States)

    Vourlitis, George L

    2017-05-01

    Anthropogenic nitrogen (N) deposition has caused a decline in native plant species and an increase in exotic plant species in many terrestrial ecosystems; however, vegetation change depends on the rate and/or duration of N input, individual species responses, interactions with other resources, and ecosystem properties such as species richness and canopy cover, soil texture, pH, and/or disturbance regime. Native shrub and exotic forb responses to N enrichment were evaluated over a 13-year field experiment in a mature coastal sage scrub (CSS) shrubland of southern California to test the hypothesis that dry-season N input will cause a decline in native shrubs and an increase in exotic annuals. Nitrogen enrichment caused the dominant native shrubs, Artemisia californica and Salvia mellifera, to respond differently, with A. californica initially increasing with N input but declining thereafter and S. mellifera declining consistently over the 13-year-period. Both species exhibited higher canopy dieback during drought conditions, especially in N plots. Brassica nigra, an exotic annual, invaded N plots significantly more than control plots, but only after 10 years of N addition and a prolonged drought, which increased native shrub canopy dieback. These results indicate a possible synergism between N enrichment and drought on native shrub and exotic forb abundance, which would have important implications for plant diversity in semi-arid shrublands of southwest US that are anticipated to experience an increase in anthropogenic N enrichment and the frequency and duration of drought.

  11. Plant sterol-enriched fermented milk enhances the attainment of LDL-cholesterol goal in hypercholesterolemic subjects.

    Science.gov (United States)

    Plana, Nuria; Nicolle, Catherine; Ferre, Raimon; Camps, Jordi; Cos, Rosa; Villoria, Jesus; Masana, Luis

    2008-02-01

    The number of hypercholesterolemic individuals who do not meet their cholesterol recommended targets is inappropriately high. The use of plant sterol-enriched foods could help in this clinical setting. To evaluate the efficacy and side effects of plant sterol-enriched fermented milk in reducing LDL-cholesterol and increasing the number of patients who attain their therapeutic targets. This was a multicentre, randomised, double-blind, placebo-controlled, parallel clinical trial. Eighty-three hypercholesterolemic patients that were not at therapeutic goals were studied. The patients received one 100 ml serving of either plain (control) low-fat or phytosterol enriched (1.6 g of free sterol equivalents) drinkable yogurt per day along with the main meal for 42 days. The principal variables were variation on LDL cholesterol (LDL-C) concentration and the number of patients achieving therapeutic goals after intervention. Patients on phytosterols attained an average LDL-C reduction of more than 10% (12.2% after 3 weeks; 10.6% after 6 weeks) (P = 0.001; 95% CI: 4.03-19.00) regardless of statin therapy compared to the control group. About 50% of the subjects on phytosterols, as compared to 20% of controls, attained their LDL-C target values (cholesterol (HDL-C) did not change and triglycerides (TG) were decreased by 14% (P cholesterol ratio increased. Plant sterol-enriched fermented milk significantly reduced LDL-C and increased the number of moderately hypercholesterolemic patients achieving therapeutic targets.

  12. Russian ElectroKhimPribor integrated plant - producer and supplier of enriched stable isotopes

    International Nuclear Information System (INIS)

    Tatarinov, A.N.; Polyakov, L.A.

    1997-01-01

    Russian ElectroKhimPribor Integrated Plant, as well as ORNL, is a leading production which manufactures and supplied to the world market such specific products as stable isotopes. More than 200 isotopes of 44 elements can be obtained at its electromagnetic separator. Changes being underway for a few last years in Russia affected production and distribution of stable isotopes. There arose a necessity in a new approach to handling work in this field so as to create favourable conditions for both producers and customers. As a result, positive changes in calutron operation at ElectroKhimPribor has been reached; quality management system covering all stages of production has been set up; large and attractive stock of isotopes has been created; prospective scientific isotope-based developments are taken into account when planning separation F campaigns; executing the contracts is guaranteed; business philosophy has been changed to meet maximum of customer needs. For more than forty years ElectroKhimPribor have had no claim from customers as to quality of products or implementing contracts. Supplying enriched stable isotopes virtually to all the world's leading customers, ElectroKhimPribor cooperates successfully with Canadian company Trace Science since 1996

  13. In-Born Radio Frequency Identification Devices for Safeguards Use at Gas-Centrifuge Enrichment Plants

    International Nuclear Information System (INIS)

    Ward, R.; Rosenthal, M.

    2009-01-01

    Global expansion of nuclear power has made the need for improved safeguards measures at Gas Centrifuge Enrichment Plants (GCEPs) imperative. One technology under consideration for safeguards applications is Radio Frequency Identification Devices (RFIDs). RFIDs have the potential to increase IAEA inspector's efficiency and effectiveness either by reducing the number of inspection visits necessary or by reducing inspection effort at those visits. This study assesses the use of RFIDs as an integral component of the 'Option 4' safeguards approach developed by Bruce Moran, U.S. Nuclear Regulatory Commission (NRC), for a model GCEP [1]. A previous analysis of RFIDs was conducted by Jae Jo, Brookhaven National Laboratory (BNL), which evaluated the effectiveness of an RFID tag applied by the facility operator [2]. This paper presents a similar evaluation carried out in the framework of Jo's paper, but it is predicated on the assumption that the RFID tag is applied by the manufacturer at the birth of the cylinder, rather than by the operator. Relevant diversion scenarios are examined to determine if RFIDs increase the effectiveness and/ or efficiency of safeguards in these scenarios. Conclusions on the benefits offered to inspectors by using in-born RFID tagging are presented.

  14. Safeguards Guidance for Designers of Commercial Nuclear Facilities – International Safeguards Requirements for Uranium Enrichment Plants

    Energy Technology Data Exchange (ETDEWEB)

    Philip Casey Durst; Scott DeMuth; Brent McGinnis; Michael Whitaker; James Morgan

    2010-04-01

    For the past two years, the United States National Nuclear Security Administration, Office of International Regimes and Agreements (NA-243), has sponsored the Safeguards-by-Design Project, through which it is hoped new nuclear facilities will be designed and constructed worldwide more amenable to nuclear safeguards. In the course of this project it was recognized that commercial designer/builders of nuclear facilities are not always aware of, or understand, the relevant domestic and international safeguards requirements, especially the latter as implemented by the International Atomic Energy Agency (IAEA). To help commercial designer/builders better understand these requirements, a report was prepared by the Safeguards-by-Design Project Team that articulated and interpreted the international nuclear safeguards requirements for the initial case of uranium enrichment plants. The following paper summarizes the subject report, the specific requirements, where they originate, and the implications for design and construction. It also briefly summarizes the established best design and operating practices that designer/builder/operators have implemented for currently meeting these requirements. In preparing the subject report, it is recognized that the best practices are continually evolving as the designer/builder/operators and IAEA consider even more effective and efficient means for meeting the safeguards requirements and objectives.

  15. Boron removal from wastewater using adsorbents.

    Science.gov (United States)

    Kluczka, J; Trojanowska, J; Zolotajkin, M; Ciba, J; Turek, M; Dydo, P

    2007-01-01

    In the present study, boron adsorption on activated alumina and activated carbon impregnated with calcium chloride, tartaric acid and mannitol was investigated. The adsorbate in question was the wastewater from the chemical landfill in Tarnowskie Gory of 25-70 mg l(-1) boron content. The removal of boron from the above-described wastewater was examined in the static (batch) and dynamic (column) experiments. The static experiments were carried out to assess boron adsorption isotherms, based on which the most efficient adsorbent as well as the rough resin load was determined. On the basis of the dynamic experiment results, the boron adsorptive capacities of the examined resins were deduced. It was concluded that the use of the impregnants increased the ability of activated carbon to adsorb boron. Granulated activated carbon WG-12 impregnated with mannitol was found to be the most promising for the boron removal from wastewater of the Chemical Wastewater Plant in Tarnowskie Gory.

  16. Evaluation of two hybrid poplar clones as constructed wetland plant species for treating saline water high in boron and selenium, or waters only high in boron.

    Science.gov (United States)

    Zhu, Hui; Bañuelos, Gary

    2017-07-05

    Wetland mesocosms were constructed to assess two hybrid poplar clones (Populustrichocarpa×P. deltoides×P. nigra '345-1' and '347-14') for treating saline water high in boron (B) and selenium (Se), and a hydroponic experiment was performed to test the B tolerance and B accumulation in both clones. In the mesocosm experiment, clone 345-1 exhibited no toxic symptoms at an EC of 10mScm -1 , while clone 347-14 showed slight toxic symptoms at 7.5mScm -1 . The removal percentages of B, Se, sodium (Na), and chloride (Cl) ranged from 26.7-45.6%, 50-69.4%, 18.4-24.0%, and 15.8-23.2%, respectively, by clone 345-1, and from 22.9-29.4%, 31.7-43.8%, 16.5-24.2%, and 14.9-23.9%, respectively, by clone 347-1. In the hydroponic experiment, B toxic symptoms were observed at treatments of 150 and 200mg B L -1 for clones 345-1 and 347-14, respectively. The greatest leaf B concentrations of 3699 and 1913mgkg -1 were found in clone 345-1 and clone 347-14, respectively. The translocation factor (TF) of clone 347-14 was less than clone 345-1. Clone 345-1 only showed significantly greater (Premoval percentages than clone 347-14 when B treatment was removed B and Se in constructed wetlands. Copyright © 2017. Published by Elsevier B.V.

  17. One-Step Preparation of Phenyl Boron-Modified Magnetic Mesoporous Silica for Selective Enrichment of cis-Diol-Containing Substances

    Directory of Open Access Journals (Sweden)

    Hua Fu

    2018-03-01

    Full Text Available For enrichment and separation of cis-diol-containing compounds from biomatrix, a new type of magnetic nanoparticles named MS-48-PBSC, whichwas facilely prepared in a one-step heterogeneous reaction. The morphology results demonstrated that the MS-48-PBSC was a spherical nanomaterial containing a core of silica-coated magnetic particle with a diameter of about 200 nm, and a cover layer of mesoporous silica with a thickness of approximate 50 nm. The characterization results showed that MS-48-PBSC presented a pore size of 4.2 nm, a surface area of 548 m2·g−1, and a pore volume of 0.30 cm3·g−1. The MS-48-PBSC also exhibited magnetism of 42 emu·g−1 that contributed to the easy separation of magnetic nanomaterial within 30 s from the matrix with the aid of the external magnetic field. In addition, the MS-48-PBSC exhibited high adsorption capacity for adenosine, xanthosine, uridine, sialic acid, and teicoplanin with 0.60, 0.51, 0.42, 0.75, and 1.26 mg/g, respectively, and showed a high selectivity for the cis-diol structure compounds, relative to interferences of bovine serum albumin, guanine, uric acid, and xanthine. The recoveries of adenosine, xanthosine, uridine, sialic acid, and teicoplanin were 71.8–114.1% with relative standard deviation (RSD ≤ 8.6%, and the enrichment factors of them were 8–11. MS-48-PBSC exhibited quick separation capability from matrix, high adsorption capacity and size exclusion for bovine serum albumin, which could meet the requirements of separation and enrichment for substances with a cis-diol structure.

  18. Compton DIV: Using a Compton-Based Gamma-Ray Imager for Design Information Verification of Uranium Enrichment Plants

    International Nuclear Information System (INIS)

    Burks, M.; Verbeke, J.; Dougan, A.; Wang, T.; Decman, D.

    2009-01-01

    A feasibility study has been performed to determine the potential usefulness of Compton imaging as a tool for design information verification (DIV) of uranium enrichment plants. Compton imaging is a method of gamma-ray imaging capable of imaging with a 360-degree field of view over a broad range of energies. These systems can image a room (with a time span on the order of one hour) and return a picture of the distribution and composition of radioactive material in that room. The effectiveness of Compton imaging depends on the sensitivity and resolution of the instrument as well the strength and energy of the radioactive material to be imaged. This study combined measurements and simulations to examine the specific issue of UF 6 gas flow in pipes, at various enrichment levels, as well as hold-up resulting from the accumulation of enriched material in those pipes. It was found that current generation imagers could image pipes carrying UF 6 in less than one hour at moderate to high enrichment. Pipes with low enriched gas would require more time. It was also found that hold-up was more amenable to this technique and could be imaged in gram quantities in a fraction of an hour. another questions arises regarding the ability to separately image two pipes spaced closely together. This depends on the capabilities of the instrument in question. These results are described in detail. In addition, suggestions are given as to how to develop Compton imaging as a tool for DIV

  19. Criticality Calculations for a Typical Nuclear Fuel Fabrication Plant with Low Enriched Uranium

    International Nuclear Information System (INIS)

    Elsayed, Hade; Nagy, Mohamed; Agamy, Said; Shaat, Mohmaed

    2013-01-01

    The operations with the fissile materials such as U 235 introduce the risk of a criticality accident that may be lethal to nearby personnel and can lead the facility to shutdown. Therefore, the prevention of a nuclear criticality accident should play a major role in the design of a nuclear facility. The objectives of criticality safety are to prevent a self-sustained nuclear chain reaction and to minimize the consequences. Sixty criticality accidents were occurred in the world. These are accidents divided into two categories, 22 accidents occurred in process facilities and 38 accidents occurred during critical experiments or operations with research reactor. About 21 criticality accidents including Japan Nuclear Fuel Conversion Co. (JCO) accident took place with fuel solution or slurry and only one accident occurred with metal fuel. In this study the nuclear criticality calculations have been performed for a typical nuclear fuel fabrication plant producing nuclear fuel elements for nuclear research reactors with low enriched uranium up to 20%. The calculations were performed for both normal and abnormal operation conditions. The effective multiplication factor (k eff ) during the nuclear fuel fabrication process (Uranium hexafluoride - Ammonium Diuranate conversion process) was determined. Several accident scenarios were postulated and the criticalities of these accidents were evaluated. The computer code MCNP-4B which based on Monte Carlo method was used to calculate neutron multiplication factor. The criticality calculations Monte Carlo method was used to calculate neutron multiplication factor. The criticality calculations were performed for the cases of, change of moderator to fuel ratio, solution density and concentration of the solute in order to prevent or mitigate criticality accidents during the nuclear fuel fabrication process. The calculation results are analyzed and discussed

  20. Effects of a Plant Sterol or Stanol Enriched Mixed Meal on Postprandial Lipid Metabolism in Healthy Subjects.

    Directory of Open Access Journals (Sweden)

    Sabine Baumgartner

    Full Text Available Evidence is increasing that plant sterols and stanols not only lower fasting serum low-density lipoprotein concentrations, but also those of triglycerides (TG. Insight into effects of these components on postprandial TG metabolism, an emerging risk factor for cardiovascular disease, is missing.Our objective was to examine the 8-hour postprandial response after consuming plant sterol or stanol enriched margarine as part of a mixed meal.This postprandial study was part of a randomized crossover study in which 42 subjects consumed plant sterol enriched (3 g/d plant sterols, plant stanol enriched (3 g/d plant stanols, and control margarines for 4 weeks. After each period, subjects consumed a shake enriched with 3g plant sterols (sterol period, 3g plant stanols (stanol period or no addition (control period. Subjects received a second shake with no addition after 4 hours.TG and apoB48 incremental areas under the curves (iAUC of the total (0-8h and 1st meal response (0-4h were comparable between the meals and in all age categories (I:18-35y, II:36-52y, III:53-69y. In subjects aged 53-69y, TG iAUC after the 2nd meal (4-8h was higher in the stanol period as compared with the sterol (63.1±53.0 mmol/L/min; P < 0.01 and the control period (43.2±52.4 mmol/L/min; P < 0.05. ApoB48 iAUC after the 2nd meal was higher after the stanol than after the sterol period (67.1±77.0 mg/L/min; P < 0.05 and tended to be higher than after the control period (43.1±64.5 mg/L/min; P = 0.08 in subjects aged 53-69y. These increased postprandial responses may be due to reduced lipoprotein lipase activity, since postprandial apoCIII/II ratios were increased after stanol consumption compared with the control meal.Postprandial TG and apoB48 responses are age-dependently increased after plant stanol consumption, which might be related to a changed clearance of triglyceride-rich lipoproteins.ClinicalTrials.gov NCT01559428.

  1. Comparison of Six DNA Extraction Procedures and the Application of Plastid DNA Enrichment Methods in Selected Non-photosynthetic Plants

    Directory of Open Access Journals (Sweden)

    Shin-Yi Shyu

    2013-12-01

    Full Text Available Genomic DNA was isolated using three DNA extraction commercial kits and three CTAB-based methods for two non-photosynthetic plants, Balanophora japonica and Mitrastemon kanehirai. The quality of the isolated DNA was evaluated and subjected to following restriction enzyme digestions. All six procedures yielded DNA of sufficient quality for PCR, and the method described by Barnwell et al. (1998 performed well in isolating DNA from both species for restriction enzyme digestion. In addition, we succeeded to enrich plastid DNA content by using the methods depending on a high salt buffer to deplete nuclear material. The ‘high salt’ methods based on protocol presented by Milligan (1989 were able to increase plastid DNA effectively and significantly reduce nuclear DNA from M. kanehirai. The plastid DNA enrichment protocols are inexpensive and not time-consuming, and may be applicable to other non-photosynthetic plants.

  2. Crystalline boron nitride aerogels

    Energy Technology Data Exchange (ETDEWEB)

    Zettl, Alexander K.; Rousseas, Michael; Goldstein, Anna P.; Mickelson, William; Worsley, Marcus A.; Woo, Leta

    2017-12-12

    This disclosure provides methods and materials related to boron nitride aerogels. For example, one aspect relates to a method for making an aerogel comprising boron nitride, comprising: (a) providing boron oxide and an aerogel comprising carbon; (b) heating the boron oxide to melt the boron oxide and heating the aerogel; (c) mixing a nitrogen-containing gas with boron oxide vapor from molten boron oxide; and (d) converting at least a portion of the carbon to boron nitride to obtain the aerogel comprising boron nitride. Another aspect relates to a method for making an aerogel comprising boron nitride, comprising heating boron oxide and an aerogel comprising carbon under flow of a nitrogen-containing gas, wherein boron oxide vapor and the nitrogen-containing gas convert at least a portion of the carbon to boron nitride to obtain the aerogel comprising boron nitride.

  3. Effect of plant sterol-enriched diets on plasma and egg yolk cholesterol concentrations and cholesterol metabolism in laying hens.

    Science.gov (United States)

    Liu, X; Zhao, H L; Thiessen, S; House, J D; Jones, P J H

    2010-02-01

    Egg exists as a major dietary source of cholesterol in Western diets. In North America, laying hen diets are usually devoid of cholesterol when diets are formulated to exclude animal-based products. Hence, laying hens meet their physiological cholesterol requirement through de novo synthesis. Plant sterols exert a cholesterol-lowering effect in humans by interfering with intestinal sterol absorption. However, it is unknown whether plant sterol supplementation could be effective in reducing intestinal reabsorption of biliary cholesterol in laying hens, thus modulating whole body cholesterol in favor of lower plasma and yolk cholesterol content. The current study was designed to investigate the effect of diets enriched with 0, 0.5, 1, and 2% plant sterols on cholesterol absorption, synthesis, as well as plasma, liver, and egg yolk cholesterol concentrations in laying hens. After 8 wk of plant sterol intervention (first 2 wk were acclimatization), feed intake, BW, egg weight, egg yolk weight, egg production, Haugh units, liver mass, plasma, and hepatic cholesterol concentrations did not differ as a function of plant sterol supplementation. Egg cholesterol concentrations (mg/g) fluctuated during the 6-wk experimental period. At wk 6, a minor reduction in egg yolk cholesterol concentration (mg per g of yolk, Pcholesterol-enriched diets, respectively. However, such result failed to affect total egg cholesterol content. No statistical difference was observed across treatments over 6 wk. Neither cholesterol absorption rates nor synthesis differed as a function of treatment. Results suggested that overall cholesterol content in egg yolk was not affected by feeding hens plant sterol-enriched diets over 6 wk.

  4. XPS analysis of boron doped heterofullerenes

    Energy Technology Data Exchange (ETDEWEB)

    Schnyder, B.; Koetz, R. [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Muhr, H.J.; Nesper, R. [ETH Zurich, Zurich (Switzerland)

    1997-06-01

    Boron heterofullerenes were generated through arc-evaporation of doped graphite rods in a helium atmosphere. According to mass spectrometric analysis only mono-substituted fullerenes like C{sub 59}B, C{sub 69}B and higher homologues together with a large fraction of higher undoped fullerenes were extracted and enriched when pyridine was used as the solvent. XPS analysis of the extracts indicated the presence of two boron species with significantly different binding energies. One peak was assigned to borid acid. The second one corresponds to boron in the fullerene cage, which is mainly C{sub 59}B, according to the mass spectrum. This boron is in a somewhat higher oxidation state than that of ordinary boron-carbon compounds. The reported synthesis and extraction procedure opens a viable route for production of macroscopic amounts of these compounds. (author) 2 figs., 1 tab., 7 refs.

  5. Effects of dietary boron on performance, egg production, egg quality ...

    African Journals Online (AJOL)

    engin

    Body weight was not affected by dietary boron supplementation at 16 and 40 weeks of age. ... and human nutrition. In bone metabolism, boron interacts with Ca, vitamin D and Mg (Chapin et al., 1998). In animals and plants, boron affects at least 26 enzymes involved in substrate metabolism, insulin release, oxidation and.

  6. Communication dated 19 May 2011 received from the Resident Representative of the United Kingdom of Great Britain and Northern Ireland to the Agency regarding Assurance of Supply of Enrichment Services and Low Enriched Uranium for Use in Nuclear Power Plants

    International Nuclear Information System (INIS)

    2011-01-01

    The Secretariat has received a letter dated 19 May 2011 from the Resident Representative of the United Kingdom of Great Britain and Northern Ireland to the Agency, attaching the Proposal for the Assurance of Supply of Enrichment Services and Low Enriched Uranium for Use in Nuclear Power Plants, as described in document GOV/2011/10. As requested by the Resident Representative, the letter and its attachment are circulated herewith for information of all Member States [es

  7. Communication dated 19 May 2011 received from the Resident Representative of the United Kingdom of Great Britain and Northern Ireland to the Agency regarding Assurance of Supply of Enrichment Services and Low Enriched Uranium for Use in Nuclear Power Plants

    International Nuclear Information System (INIS)

    2011-01-01

    The Secretariat has received a letter dated 19 May 2011 from the Resident Representative of the United Kingdom of Great Britain and Northern Ireland to the Agency, attaching the Proposal for the Assurance of Supply of Enrichment Services and Low Enriched Uranium for Use in Nuclear Power Plants, as described in document GOV/2011/10. As requested by the Resident Representative, the letter and its attachment are circulated herewith for information of all Member States

  8. Uranium enrichment

    International Nuclear Information System (INIS)

    Rae, H.K.; Melvin, J.G.

    1988-06-01

    Canada is the world's largest producer and exporter of uranium, most of which is enriched elsewhere for use as fuel in LWRs. The feasibility of a Canadian uranium-enrichment enterprise is therefore a perennial question. Recent developments in uranium-enrichment technology, and their likely impacts on separative work supply and demand, suggest an opportunity window for Canadian entry into this international market. The Canadian opportunity results from three particular impacts of the new technologies: 1) the bulk of the world's uranium-enrichment capacity is in gaseous diffusion plants which, because of their large requirements for electricity (more than 2000 kW·h per SWU), are vulnerable to competition from the new processes; 2) the decline in enrichment costs increases the economic incentive for the use of slightly-enriched uranium (SEU) fuel in CANDU reactors, thus creating a potential Canadian market; and 3) the new processes allow economic operation on a much smaller scale, which drastically reduces the investment required for market entry and is comparable with the potential Canadian SEU requirement. The opportunity is not open-ended. By the end of the century the enrichment supply industry will have adapted to the new processes and long-term customer/supplier relationships will have been established. In order to seize the opportunity, Canada must become a credible supplier during this century

  9. Use of 15N enriched plant material for labelling of soil nitrogen in legume dinitrogen fixation experiments

    International Nuclear Information System (INIS)

    Jensen, E.S.

    1989-06-01

    The soil nitrogen in a field plot was labelled with nitrogen-15 (15N) by incorporating labelled plant material derived from previous experiments. The plot was used the following 3 years for determination of the amount of N2 fixed by different leguminous plants. The atom % 15N excess in grains of cereals grown as reference crops was 0.20, 0.05 and 0.03 in the 3 years, respectively. In the first year the level of enrichment was adequate for estimating symbiotic nitrogen fixation. In the second and third year lack of precision in determination of the 15N/14N ratios of legume N, may have caused an error in estimates of nitrogen fixation. About 23% of the labelled N was taken up by plants during the 3 years of cropping; after 4 years about 44% of the labelled N was found still to be present in the top soil. The labelling of the soil nitrogen with organic bound 15N, compared to adding mineral 15N at sowing, is advantageous because the labelled N is released by mineralization so that the enrichment of the plant available soil N pool become more uniform during the growth season; and high levels of mineral N, which may depress the fixation process, is avoided. (author) 7 tabs., 1 ill., 30 refs

  10. Plant sterols-enriched diet decreases small, dense LDL-cholesterol levels in children with hypercholesterolemia: a prospective study.

    Science.gov (United States)

    Garoufi, Anastasia; Vorre, Styliani; Soldatou, Alexandra; Tsentidis, Charalampos; Kossiva, Lydia; Drakatos, Antonios; Marmarinos, Antonios; Gourgiotis, Dimitrios

    2014-05-03

    Small dense low density lipoprotein-cholesterol (sdLDL-C) molecules are more atherogenic compared with large buoyant ones. Phytosterols-enriched diets are effective in decreasing total cholesterol (TC) and low density lipoprotein-cholesterol (LDL-C) concentrations in hyperlipidemic children without significant adverse effects. Limited data on the impact of such a diet on sdLDL-C levels is available in adults while there are no reports concerning children. The purpose of this study is to prospectively evaluate the effect of the daily consumption of 2 g of plant sterols on sdLDL-C levels in children with hypercholesterolemia. Fifty-nine children, 25 with LDL-C ≥ 3.4 mmol/l (130 mg/dl) and 34 with LDL-C yogurt-drink enriched with 2 g of plant sterols was added to the daily diet of hypercholesterolemic children and 6-12 months later lipid profiles were reassessed. Direct quantitative methods were used to measure LDL-C and sdLDL-C levels. The consumption of plant sterols reduced sdLDL-C significantly (p cholesterol (NonHDL-C) and apolipoprotein B (ApoB) levels also decreased significantly (p 10% in sixteen children (64%), independently from baseline levels, sex, age and body mass index (BMI). High density lipoprotein-cholesterol (HDL-C), lipoprotein a [Lp(a)], and triglycerides (TGs) levels remained unaffected. Plant sterols decrease sdLDL-C significantly and may be beneficial for children with hypercholesterolemia.

  11. The elimination of chlorinated, chlorofluorocarbon, and other RCRA hazardous solvents from the Y-12 Plant's enriched uranium operations

    International Nuclear Information System (INIS)

    Johnson, D.H.; Patton, R.L.; Thompson, L.M.

    1990-01-01

    A major driving force in waste minimization within the plant is the reduction of mixed radioactive wastes associated with operations on highly enriched uranium. High enriched uranium has a high concentration of the uranium-235 isotope (up to 97.5% enrichment) and is radioactive, giving off alpha and low level gamma radiation. The material is fissionable with as little as two pounds dissolved in water being capable of producing a spontaneous chain reaction. For these reasons the material is processed in small batches or small geometries. Additionally, the material is completely recycled because of its strategic and monetary value. Since the early eighties, the plant has had an active waste minimization program which has concentrated on substitution of less hazardous solvents wherever possible. The following paper summarizes efforts in two areas - development of a water-based machining coolant to replace perchloroethylene and substitution of an aliphatic solvent to replace solvents producing hazardous wastes as defined by the Resource, Conservation, and Recovery Act (RCRA)

  12. A novel 10B-enriched carboranyl-containing phthalocyanine as a radio- and photo-sensitising agent for boron neutron capture therapy and photodynamic therapy of tumours: in vitro and in vivo studies.

    Science.gov (United States)

    Friso, Elisabetta; Roncucci, Gabrio; Dei, Donata; Soncin, Marina; Fabris, Clara; Chiti, Giacomo; Colautti, Paolo; Esposito, Juan; De Nardo, Laura; Riccardo Rossi, Carlo; Nitti, Donato; Giuntini, Francesca; Borsetto, Lara; Jori, Giulio

    2006-01-01

    The synthesis of a Zn(ii)-phthalocyanine derivative bearing four 10B-enriched o-carboranyl units (10B-ZnB4Pc) and its natural isotopic abundance analogue (ZnB4Pc) in the peripheral positions of the tetraazaisoindole macrocycle is presented. The photophysical properties of ZnB4Pc, as tested against model biological systems, were found to be similar with those typical of other photodynamically active porphyrin-type photosensitisers, including a singlet oxygen quantum yield of 0.67. The carboranyl-carrying phthalocyanine was efficiently accumulated by B16F1 melanotic melanoma cells in vitro, appeared to be partitioned in at least some subcellular organelles and, upon red light irradiation, induced extensive cell mortality. Moreover, ZnB4Pc, once i.v.-injected to C57BL/6 mice bearing a subcutaneously transplanted pigmented melanoma, photosensitised an important tumour response, provided that the irradiation at 600-700 nm was performed 3 h after the phthalocyanine administration, when appreciable concentrations of ZnB4Pc were still present in the serum. Analogously, irradiation of the 10B-ZnB4Pc-loaded pigmented melanoma with thermal neutrons 24 h after injection led to a 4 day delay in tumour growth as compared with control untreated mice. These results open the possibility to use one chemical compound as both a photosensitising and a radiosensitising agent for the treatment of tumours by the combined application of photodynamic therapy and boron neutron capture therapy.

  13. Economical benefits for the use of slightly enriched fuel elements at the Atucha-I nuclear power plant

    International Nuclear Information System (INIS)

    Sidelnik, J.I.; Sosa, M.A.

    1987-01-01

    The fuel represents a very important factor in the operative cost of the Atucha I nuclear power plant. This cost is drastically reduced with the use of fuel elements of slightly enriched uranium. The annual saving is analyzed with actual values for fuel elements with an enrichment of 0.85% by weight of U-235. With the reactor core in equilibrium state the annual saving achieved is approximately 7.5-10 u$s. According to the present irradiation plan, the benefit for the transition period is studied. An analysis of the sensitivity to differential increments in factors determining the cost of fuel elements or to changes in manufacturing losses is also performed, calculating its effect on the waste, the storage of irradiated elements and the amount of UO 2 required. (Author)

  14. The technical feasibility of uranium enrichment for nuclear bomb construction at the parallel nuclear program plant

    International Nuclear Information System (INIS)

    Rosa, L.P.

    1990-01-01

    It is discussed the hole of the Parallel Nuclear Program is Brazil and the feasibility of uranium enrichment for nuclear bomb construction. This program involves two research centers, one belonging to the brazilian navy and another to the aeronautics. Some other brazilian institutes like CTA, IPEN, COPESP and CETEX and also taking part in the program. (A.C.A.S.)

  15. Determination of plant stanols and plant sterols in phytosterol enriched foods with a gas chromatographic-flame ionization detection method: NMKL collaborative study.

    Science.gov (United States)

    Laakso, Päivi H

    2014-01-01

    This collaborative study with nine participating laboratories was conducted to determine the total plant sterol and/or plant stanol contents in phytosterol fortified foods with a gas chromatographic method. Four practice and 12 test samples representing mainly commercially available foodstuffs were analyzed as known replicates. Twelve samples were enriched with phytosterols, whereas four samples contained only natural contents of phytosterols. The analytical procedure consisted of two alternative approaches: hot saponification method, and acid hydrolysis treatment prior to hot saponification. As a result, sterol/stanol compositions and contents in the samples were measured. The amounts of total plant sterols and total plant stanols varying from 0.005 to 8.04 g/100 g product were statistically evaluated after outliers were eliminated. The repeatability RSD (RSDr) varied from 1.34 to 17.13%. The reproducibility RSD (RSDR) ranged from 3.03 to 17.70%, with HorRat values ranging from 0.8 to 2.1. When only phytosterol enriched food test samples are considered, the RSDr ranged from 1.48 to 6.13%, the RSD, ranged from 3.03 to 7.74%, and HorRat values ranged from 0.8 to 2.1. Based on the results of this collaborative study, the study coordinator concludes the method is fit for its purpose.

  16. Nutrient enrichment effects on photosynthesis in the wetland plants Typha orientalis and Phormium tenax

    DEFF Research Database (Denmark)

    Sorrell, Brian Keith; Brix, Hans; Tanner, Chris

    chlorophyll in its leaf tissue than flax. Photosynthetic rates were significantly higher in raupo than flax in both field and experimental situations, except at very low nutrient availability, where they were similar. Photosynthesis in raupo increased strongly with N availability, whereas there was only...... a weak relationship between N and photosynthesis in flax in experimental cultures, and no effect at all of N on flax photosynthesis in the field. Both species had significantly higher photosynthesis rates in experimental cultures than in the field; for raupo this was due to N limitation in the field......Anthropogenic nutrient enrichment can allow fast-growing species with high photosynthetic capacity to out-compete less vigorous species in freshwater wetlands. We compared the effect of nutrient enrichment on photosynthetic gas exchange in two tall canopy dominants, the inherently fast...

  17. A phenol-enriched cuticle is ancestral to lignin evolution in land plants

    OpenAIRE

    Renault, Hugues; Alber, Annette; Horst, Nelly A.; Basilio Lopes, Alexandra; Fich, Eric A.; Kriegshauser, Lucie; Wiedemann, Gertrud; Ullmann, Pascaline; Herrgott, Laurence; Erhardt, Mathieu; Pineau, Emmanuelle; Ehlting, J?rgen; Schmitt, Martine; Rose, Jocelyn K. C.; Reski, Ralf

    2017-01-01

    Lignin, one of the most abundant biopolymers on Earth, derives from the plant phenolic metabolism. It appeared upon terrestrialization and is thought critical for plant colonization of land. Early diverging land plants do not form lignin, but already have elements of its biosynthetic machinery. Here we delete in a moss the P450 oxygenase that defines the entry point in angiosperm lignin metabolism, and find that its pre-lignin pathway is essential for development. This pathway does not involv...

  18. Enrichment of naturally occurring radionuclides and trace elements in Yatagan and Yenikoy coal-fired thermal power plants, Turkey.

    Science.gov (United States)

    Ozden, Banu; Guler, Erkan; Vaasma, Taavi; Horvath, Maria; Kiisk, Madis; Kovacs, Tibor

    2018-08-01

    Coal, residues and waste produced by the combustion of the coal contain naturally occurring radionuclides such as 238 U, 226 Ra, 210 Pb, 232 Th and 40 K and trace elements such as Cd, Cr, Pb, Ni and Zn. In this work, coal and its combustion residues collected from Yatagan and Yenikoy coal fired thermal power plants (CPPs) in Turkey were studied to determine the concentrations of natural radionuclides and trace elements, and their enrichments factors to better understand the radionuclide concentration processes within the combustion system. In addition, the utilization of coal fly ash as a secondary raw material in building industry was also studied in terms of radiological aspects. Fly ash samples were taken at different stages along the emission control system of the thermal power plants. Activity concentrations of naturally occurring radionuclides were determined with Canberra Broad Energy Germanium (BEGe) detector BE3830-P and ORTEC Soloist PIPS type semiconductor detector. The particle size distribution and trace elements contents were determined in various ash fractions by the laser scattering particle size distribution analyzer and inductively coupled plasma (ICP-OES). From the obtained data, natural radionuclides tend to condense on fly ash with and the activity concentrations increase as the temperature drop in CPPs. Measured 210 Pb and 210 Po concentration varied between 186 ± 20-1153 ± 44 Bq kg -1 , and 56 ± 5-1174 ± 45 Bq kg -1 , respectively. The highest 210 Pb and 210 Po activity concentrations were determined in fly ash taken from the temporary storage point as 1153 ± 44 Bq kg -1 and 1174 ± 45 Bq kg -1 , respectively. There were significant differences in the activity concentrations of some natural radionuclide and trace elements (Pb and Zn) contents in ash fractions among the sampling point inside both of the plants (ANOVA, p ash sample analysis showed an increase activity concentration and enrichment factors towards the

  19. Migration and Enrichment of Arsenic in the Rock-Soil-Crop Plant System in Areas Covered with Black Shale, Korea

    Directory of Open Access Journals (Sweden)

    Ji-Min Yi

    2003-01-01

    Full Text Available The Okchon black shale, which is part of the Guryongsan Formation or the Changri Formation of Cambro-Ordovician age in Korea provides a typical example of natural geological materials enriched with potentially toxic elements such as U, V, Mo, As, Se, Cd, and Zn. In this study, the Dukpyung and the Chubu areas were selected to investigate the migration and enrichment of As and other toxic elements in soils and crop plants in areas covered with black shale. Rock and soil samples digested in 4-acid solution (HCl+HNO3+HF+HClO4 were analyzed for As and other heavy metals by ICP-AES and ICP-MS, and plant samples by INAA. Mean concentration of As in Okchon black shale is higher than those of both world average values of shale and black shale. Especially high concentration of 23.2 mg As kg-1 is found in black shale from the Dukpyung area. Mean concentration of As is highly elevated in agricultural soils from the Dukpyung (28.2 mg kg-1 and the Chubu areas (32.6 mg kg-1. As is highly elevated in rice leaves from the Dukpyung (1.14 mg kg-1 and the Chubu areas (1.35 mg kg-1. The biological absorption coefficient (BAC of As in plant species decreases in the order of rice leaves > corn leaves > red pepper = soybean leaves = sesame leaves > corn stalks > corn grains. This indicates that leafy plants tend to accumulate As from soil to a greater degree than cereal products such as grains.

  20. The effect of plant sterol-enriched turkey meat on cholesterol bio-accessibility during in vitro digestion and Caco-2 cell uptake.

    Science.gov (United States)

    Grasso, S; Harrison, S M; Monahan, F J; Brayden, D; Brunton, N P

    2018-03-01

    This study evaluated the effect of a plant sterol-enriched turkey product on cholesterol bio-accessibility during in vitro digestion and cholesterol uptake by Caco-2 monolayers. Turkey products, one plant sterol-enriched (PS) and one plant sterol-free (C), were produced in an industrial pilot plant. Before simulated digestion, matrices were spiked with cholesterol (1:5 weight ratio of cholesterol to plant sterol). Plant sterols were included at a concentration equivalent to the minimum daily intake recommended by the European Food Safety Authority (EFSA) for cholesterol lowering. After simulated digestion, the percentage of cholesterol micellarization and uptake by Caco-2 cells in the presence of PS meat were measured. Compared to C meat, PS meat significantly inhibited cholesterol micellarization on average by 24% and Caco-2 cell accumulation by 10%. This study suggests that plant sterols in meat can reduce cholesterol uptake by intestinal epithelia and it encourages efforts to make new PS-based functional foods.

  1. Enrichment ratios of elements in selected plant species from black coal mine dumps in Lower Silesia (Poland)

    Energy Technology Data Exchange (ETDEWEB)

    Samecka-Cymerman, A.; Kempers, A.J. [University of Wroclaw, Wroclaw (Poland)

    2003-07-01

    Concentration of the metals Al, Ba, Cd, Co, Cr, Cu, Mn, Ni, Pb, Sr, Zn and V as well as N, P, K, Ca, Mg, Fe and S were measured in soils and in two tree species (leaves of Betula pendula and Salix caprea) and two herbs (whole above-ground parts of Solidago canadensis and Tanacetum vulgare) sampled from dumps in the Walbrzych coal mine area (Lower Silesia, SW Poland). These plants, as used to evaluate the distribution of elements in the examined dumps, contained elevated levels of Cd, Co, Cu, Mn, Ni, Pb and Zn. Especially the highest levels of Mn in Betula pendula seriously exceed background values. Betula pendula characterized also the highest enrichment ratio for Mn, Salix caprea for Ni and Sr and Tanacetum vulgare for Cu. Test-t indicated that from both herbs Tanace-tum vulgare accumulated much more K, N, S and Zn than Solidago canadensis and of both trees Salix caprea accumulated significantly more Cd, Cu, K and Ca than Betula pendula, while this last species accumulated significantly more Fe and Mn than Salix caprea. A post hoc LSD test indicated that all examined plants had similar enrichment ratios for Al, Pb and V.

  2. Association between Soil Fertility and Growth Performance of Planted Shorea macrophylla (de Vriese after Enrichment Planting at Rehabilitation Sites of Sampadi Forest Reserve, Sarawak, Malaysia

    Directory of Open Access Journals (Sweden)

    Mugunthan Perumal

    2017-01-01

    Full Text Available A study was conducted to determine the status of soil properties after enrichment planting in comparison to an adjacent secondary forest and to evaluate the effect of enrichment planting of Shorea macrophylla (de Vriese on the soil fertility status with special reference to Soil Fertility Index (SFI and Soil Evaluation Factor (SEF at Sampadi Forest Reserve, Sarawak. The study sites were stands rehabilitated in different years (1996: SM96; 1997: SM97; 1998: SM98; 1999: SM99 and secondary forest (SF. Findings indicated that the soils at rehabilitation sites and SF were strongly acidic in nature, with pH less than 5.50, poor soil exchangeable bases, and nutrient status. The soils were relatively of sandy clay loam to sandy clay. Principal Component Analysis revealed the three most significant components of the soil properties which explained 76.3% of the total variation. At surface soils, SFI was correlated with tree growth parameters of S. macrophylla, indicating that SFI is an applicable soil quality index as compared to SEF. Notwithstanding, a significant association was found between soil available phosphorus and planted S. macrophylla, indicating that soil phosphorus is a better indicator than SFI. Further studies on other environmental factors influencing tree growth performance, early establishment of experimental reforestation at nursery, and field should be implemented to obtain the initial data on seedling growth performance prior to outplanting.

  3. Combined effects of CO2 enrichment, changes in diurnal light level and water stress on foliar metabolites of potato plants grown in naturally sunlit controlled environment chambers

    Science.gov (United States)

    Potato plants (Solanum tuberosum L. cv Kennebec) were grown in outdoor, naturally sunlit, soil-plant-atmosphere research (SPAR) chambers. Drought treatments were imposed at post-tuber initiation stage to assess water stress effects on leaf metabolites, and interactions with enriched CO2 concentrati...

  4. The effect of boron deficiency on gene expression and boron compartmentalization in sugarbeet

    Science.gov (United States)

    NIP5, BOR1, NIP6, and WRKY6 genes were investigated for their role in boron deficiency in sugar beet, each with a proposed role in boron use in model plant species. All genes showed evidence of polymorphism in fragment size and gene expression in the target genomic DNA and cDNA libraries, with no co...

  5. Processing of irradiated, enriched uranium fuels at the Savannah River Plant

    International Nuclear Information System (INIS)

    Hyder, M.L.; Perkins, W.C.; Thompson, M.C.; Burney, G.A.; Russell, E.R.; Holcomb, H.P.; Landon, L.F.

    1979-04-01

    Uranium fuels containing 235 U at enrichments from 1.1% to 94% are processed and recovered, along with neptunium and plutonium byproducts. The fuels to be processed are dissolved in nitric acid. Aluminum-clad fuels are disssolved using a mercury catalyst to give a solution rich in aluminum. Fuels clad in more resistant materials are dissolved in an electrolytic dissolver. The resulting solutions are subjected to head-end treatment, including clarification and adjustment of acid and uranium concentration before being fed to solvent extraction. Uranium, neptunium, and plutonium are separated from fission products and from one another by multistage countercurrent solvent extraction with dilute tri-n-butyl phosphate in kerosene. Nitric acid is used as the salting agent in addition to aluminum or other metal nitrates present in the feed solution. Nuclear safety is maintained through conservative process design and the use of monitoring devices as secondary controls. The enriched uranium is recovered as a dilute solution and shipped off-site for further processing. Neptunium is concentrated and sent to HB-Line for recovery from solution. The relatively small quantities of plutonium present are normally discarded in aqueous waste, unless the content of 238 Pu is high enough to make its recovery desirable. Most of the 238 Pu can be recovered by batch extraction of the waste solution, purified by counter-current solvent extraction, and converted to oxide in HB-Line. By modifying the flowsheet, 239 Pu can be recovered from low-enriched uranium in the extraction cycle; neptunium is then not recovered. The solvent is subjected to an alkaline wash before reuse to remove degraded solvent and fission products. The aqueous waste is concentrated and partially deacidified by evaporation before being neutralized and sent to the waste tanks; nitric acid from the overheads is recovered for reuse

  6. Processing of irradiated, enriched uranium fuels at the Savannah River Plant

    Energy Technology Data Exchange (ETDEWEB)

    Hyder, M L; Perkins, W C; Thompson, M C; Burney, G A; Russell, E R; Holcomb, H P; Landon, L F

    1979-04-01

    Uranium fuels containing /sup 235/U at enrichments from 1.1% to 94% are processed and recovered, along with neptunium and plutonium byproducts. The fuels to be processed are dissolved in nitric acid. Aluminum-clad fuels are disssolved using a mercury catalyst to give a solution rich in aluminum. Fuels clad in more resistant materials are dissolved in an electrolytic dissolver. The resulting solutions are subjected to head-end treatment, including clarification and adjustment of acid and uranium concentration before being fed to solvent extraction. Uranium, neptunium, and plutonium are separated from fission products and from one another by multistage countercurrent solvent extraction with dilute tri-n-butyl phosphate in kerosene. Nitric acid is used as the salting agent in addition to aluminum or other metal nitrates present in the feed solution. Nuclear safety is maintained through conservative process design and the use of monitoring devices as secondary controls. The enriched uranium is recovered as a dilute solution and shipped off-site for further processing. Neptunium is concentrated and sent to HB-Line for recovery from solution. The relatively small quantities of plutonium present are normally discarded in aqueous waste, unless the content of /sup 238/Pu is high enough to make its recovery desirable. Most of the /sup 238/Pu can be recovered by batch extraction of the waste solution, purified by counter-current solvent extraction, and converted to oxide in HB-Line. By modifying the flowsheet, /sup 239/Pu can be recovered from low-enriched uranium in the extraction cycle; neptunium is then not recovered. The solvent is subjected to an alkaline wash before reuse to remove degraded solvent and fission products. The aqueous waste is concentrated and partially deacidified by evaporation before being neutralized and sent to the waste tanks; nitric acid from the overheads is recovered for reuse.

  7. Density separation of boron particles. Final report

    International Nuclear Information System (INIS)

    Smith, R.M.

    1980-04-01

    A density distribution much broader than expected was observed in lots of natural boron powder supplied by two different sources. The material in both lots was found to have a rhombohedral crystal structure, and the only other parameters which seemed to account for such a distribution were impurities within the crystal structure and varying isotopic ratios. A separation technique was established to isolate boron particles in narrow densty ranges. The isolated fractions were subsequently analyzed for B 10 and total boron content in an effort to determine whether selective isotopic enrichment and nonhomogeneous impurity distribution were the causes for the broad density distribution of the boron powders. It was found that although the B 10 content remained nearly constant around 18%, the total boron content varied from 37.5 to 98.7%. One of the lots also was found to contain an apparently high level of alpha rhombohedral boron which broadened the density distribution considerably. During this work, a capability for removing boron particles containing gross amounts of impurities and, thereby, improving the overall purity of the remaining material was developed. In addition, the separation technique used in this study apparently isolated particles with alpha and beta rhombohedral crystal structures, although the only supporting evidence is density data

  8. Boron affects the growth and ultrastructure of castor bean plants Boro afeta o crescimento e a ultra-estrutura da mamoneira

    Directory of Open Access Journals (Sweden)

    Denis Herisson da Silva

    2008-12-01

    Full Text Available The cultivation of oleaginous plants like the castor bean guarantees employment for agricultural families and can contribute in energy and chemical sectors, especially in the northeastern semi-arid regions of Brazil. Boron (B deficiency is a widespread nutritional disorder despite the fact that various anthropogenic sources with high B content may increase soil B to toxic levels for plants. The present study was designed to investigate the ultrastructural effects of boron deficiency and toxicity on castor bean plants which were grown under greenhouse condition using plastic containers with 10 L of nutrient solution. Boron treatments comprised: control (no B; 0.27 mg L-1, 5.40 mg L-1 B pots (one plant per pot, tested in a completely randomized design with three replicates. The dry matter of all plant parts and B concentration were determined. Cellular ultrastructure was evaluated by transmission and scanning electron microscopy on samples of leaves and petioles. Dry matter yield was affected by the B absence treatment but there was no difference for the 5.4 mg L-1 B (toxic conditions treatment. A marginal leaf burn at edge and tips of oldest leaves and absence of starch granules in chloroplasts were noted for the B toxicity treatment. The deformation of the youngest leaves, the death of the apical meristem as well as the swelling of the middle lamella, absence of starch granules in chloroplasts and petiole vessels untidily were observed in the B absent treatment. It is concluded that the production and development of castor bean plants is affected by boron deficiency, but not for boron toxicity conditions.A mamoneira é uma oleaginosa com grande potencial para a geração de renda na agricultura familiar e para produção de matéria prima para a indústria química e setor energético brasileiro, especialmente em regiões do semi-árido nordestino. A deficiência de boro (B ocorre de forma generalizada no Brasil e a aplicação excessiva deste

  9. A phenol-enriched cuticle is ancestral to lignin evolution in land plants.

    Science.gov (United States)

    Renault, Hugues; Alber, Annette; Horst, Nelly A; Basilio Lopes, Alexandra; Fich, Eric A; Kriegshauser, Lucie; Wiedemann, Gertrud; Ullmann, Pascaline; Herrgott, Laurence; Erhardt, Mathieu; Pineau, Emmanuelle; Ehlting, Jürgen; Schmitt, Martine; Rose, Jocelyn K C; Reski, Ralf; Werck-Reichhart, Danièle

    2017-03-08

    Lignin, one of the most abundant biopolymers on Earth, derives from the plant phenolic metabolism. It appeared upon terrestrialization and is thought critical for plant colonization of land. Early diverging land plants do not form lignin, but already have elements of its biosynthetic machinery. Here we delete in a moss the P450 oxygenase that defines the entry point in angiosperm lignin metabolism, and find that its pre-lignin pathway is essential for development. This pathway does not involve biochemical regulation via shikimate coupling, but instead is coupled with ascorbate catabolism, and controls the synthesis of the moss cuticle, which prevents desiccation and organ fusion. These cuticles share common features with lignin, cutin and suberin, and may represent the extant representative of a common ancestor. Our results demonstrate a critical role for the ancestral phenolic metabolism in moss erect growth and cuticle permeability, consistent with importance in plant adaptation to terrestrial conditions.

  10. RDX Biodegradation by a Methanogenic Enrichment Culture Obtained from an Explosives Manufacturing Wastewater Treatment Plant

    National Research Council Canada - National Science Library

    Adrian, Neal

    1998-01-01

    .... Serum bottles containing 100 ml of a basal salts medium amended with 10 percent (v/v) sludge from the anoxic filter at the plant were amended with RDX and incubated under methanogenic conditions...

  11. Evolutionary divergence of plant borate exporters and critical amino acid residues for the polar localization and boron-dependent vacuolar sorting of AtBOR1

    KAUST Repository

    Wakuta, Shinji

    2015-01-24

    Boron (B) is an essential micronutrient for plants but is toxic when accumulated in excess. The plant BOR family encodes plasma membrane-localized borate exporters (BORs) that control translocation and homeostasis of B under a wide range of conditions. In this study, we examined the evolutionary divergence of BORs among terrestrial plants and showed that the lycophyte Selaginella moellendorffii and angiosperms have evolved two types of BOR (clades I and II). Clade I includes AtBOR1 and homologs previously shown to be involved in efficient transport of B under conditions of limited B availability. AtBOR1 shows polar localization in the plasma membrane and high-B-induced vacuolar sorting, important features for efficient B transport under low-B conditions, and rapid down-regulation to avoid B toxicity. Clade II includes AtBOR4 and barley Bot1 involved in B exclusion for high-B tolerance. We showed, using yeast complementation and B transport assays, that three genes in S. moellendorffii, SmBOR1 in clade I and SmBOR3 and SmBOR4 in clade II, encode functional BORs. Furthermore, amino acid sequence alignments identified an acidic di-leucine motif unique in clade I BORs. Mutational analysis of AtBOR1 revealed that the acidic di-leucine motif is required for the polarity and high-B-induced vacuolar sorting of AtBOR1. Our data clearly indicated that the common ancestor of vascular plants had already acquired two types of BOR for low- and high-B tolerance, and that the BOR family evolved to establish B tolerance in each lineage by adapting to their environments. © The Author 2015. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists.

  12. Model for calculating the boron concentration in PWR type reactors

    International Nuclear Information System (INIS)

    Reis Martins Junior, L.L. dos; Vanni, E.A.

    1986-01-01

    A PWR boron concentration model has been developed for use with RETRAN code. The concentration model calculates the boron mass balance in the primary circuit as the injected boron mixes and is transported through the same circuit. RETRAN control blocks are used to calculate the boron concentration in fluid volumes during steady-state and transient conditions. The boron reactivity worth is obtained from the core concentration and used in RETRAN point kinetics model. A FSAR type analysis of a Steam Line Break Accident in Angra I plant was selected to test the model and the results obtained indicate a sucessfull performance. (Author) [pt

  13. A review of the Y-12 Plant discharge of enriched uranium to the sanitary sewer (DEUSS)

    Energy Technology Data Exchange (ETDEWEB)

    1991-09-01

    The Oak Ridge Y-12 Plant is situated adjacent to the Oak Ridge city limits and is operated by the United States Department of Energy (DOE). The Y-12 Plant is located on 4,860 acres, which is collectively referred to as the Y-12 Plant site. Among the missions for which the facility is in existence are producing nuclear weapons components, supporting weapon design laboratories, and processing special nuclear materials (SNM). The Y-12 Plant is under the regulatory guidance of DOE Order 5400.5 and has complied with the technical requirements governing SNM since its issue. However, an in-depth review with appropriate documentation had not been performed, prior to the effect presented herein, to substantiate this claim. As a result of the solid waste issue, it was determined that other types of waste should be formally reviewed for content with respect to SNM. Therefore, a project was formed to investigate the conveyance of SNM through the sanitary sewer system. It is emphasized that this project addresses only effluent from the sanitary sewer system and not the storm sewer system. The project reviewed sanitary sewer data both for the Y-12 Plant and the Y-12 Plant site.

  14. A review of the Y-12 Plant discharge of enriched uranium to the sanitary sewer (DEUSS)

    International Nuclear Information System (INIS)

    1991-09-01

    The Oak Ridge Y-12 Plant is situated adjacent to the Oak Ridge city limits and is operated by the United States Department of Energy (DOE). The Y-12 Plant is located on 4,860 acres, which is collectively referred to as the Y-12 Plant site. Among the missions for which the facility is in existence are producing nuclear weapons components, supporting weapon design laboratories, and processing special nuclear materials (SNM). The Y-12 Plant is under the regulatory guidance of DOE Order 5400.5 and has complied with the technical requirements governing SNM since its issue. However, an in-depth review with appropriate documentation had not been performed, prior to the effect presented herein, to substantiate this claim. As a result of the solid waste issue, it was determined that other types of waste should be formally reviewed for content with respect to SNM. Therefore, a project was formed to investigate the conveyance of SNM through the sanitary sewer system. It is emphasized that this project addresses only effluent from the sanitary sewer system and not the storm sewer system. The project reviewed sanitary sewer data both for the Y-12 Plant and the Y-12 Plant site

  15. Boron nitride composites

    Science.gov (United States)

    Kuntz, Joshua D.; Ellsworth, German F.; Swenson, Fritz J.; Allen, Patrick G.

    2017-02-21

    According to one embodiment, a composite product includes: a matrix material including hexagonal boron nitride and one or more borate binders; and a plurality of cubic boron nitride particles dispersed in the matrix material. According to another embodiment, a composite product includes: a matrix material including hexagonal boron nitride and amorphous boron nitride; and a plurality of cubic boron nitride particles dispersed in the matrix material.

  16. Boron Nitride Nanotubes

    Science.gov (United States)

    Smith, Michael W. (Inventor); Jordan, Kevin (Inventor); Park, Cheol (Inventor)

    2012-01-01

    Boron nitride nanotubes are prepared by a process which includes: (a) creating a source of boron vapor; (b) mixing the boron vapor with nitrogen gas so that a mixture of boron vapor and nitrogen gas is present at a nucleation site, which is a surface, the nitrogen gas being provided at a pressure elevated above atmospheric, e.g., from greater than about 2 atmospheres up to about 250 atmospheres; and (c) harvesting boron nitride nanotubes, which are formed at the nucleation site.

  17. No evidence that boron influences tree species distributions in lowland tropical forests of Panama.

    Science.gov (United States)

    Turner, Benjamin L; Zalamea, Paul-Camilo; Condit, Richard; Winter, Klaus; Wright, S Joseph; Dalling, James W

    2017-04-01

    It was recently proposed that boron might be the most important nutrient structuring tree species distributions in tropical forests. Here we combine observational and experimental studies to test this hypothesis for lowland tropical forests of Panama. Plant-available boron is uniformly low in tropical forest soils of Panama and is not significantly associated with any of the > 500 species in a regional network of forest dynamics plots. Experimental manipulation of boron supply to seedlings of three tropical tree species revealed no evidence of boron deficiency or toxicity at concentrations likely to occur in tropical forest soils. Foliar boron did not correlate with soil boron along a local scale gradient of boron availability. Fifteen years of boron addition to a tropical forest increased plant-available boron by 70% but did not significantly change tree productivity or boron concentrations in live leaves, wood or leaf litter. The annual input of boron in rainfall accounts for a considerable proportion of the boron in annual litterfall and is similar to the pool of plant-available boron in the soil, and is therefore sufficient to preclude boron deficiency. We conclude that boron does not influence tree species distributions in Panama and presumably elsewhere in the lowland tropics. No claim to original US government works New Phytologist © 2016 New Phytologist Trust.

  18. The benefits of enriched boric acid in PWRs

    International Nuclear Information System (INIS)

    Wiedenmann, Debra; Nordmann, Francis

    2012-09-01

    The economics of operating pressurized water reactors (PWRs) demand increased fuel economy which in turn places increasing demands on the primary coolant chemistry. Higher energy production can be achieved by using increased enrichment of the nuclear fuel, higher fuel burn up and longer fuel cycles, which in turn requires increased amounts of neutron poison to maintain reactivity control. In addition, greater amounts of chemical shim are required when utilizing alternative, high-reactivity fuels such as mixed uranium/plutonium oxide (MOX) fuels. The B-10 isotope of boron has a high cross section for the absorption of thermal neutrons. However, this isotope comprises only ∼19.6% to 20 % of natural boron. If the boric acid is enriched in the 10 B isotope, then the maximum amount of chemical shim can be increased without exceeding the chemistry limits set by the acidity of boric acid or the concentration limit of lithium (PWR) or potassium (VVER). With sufficient isotopic enrichment, it therefore becomes possible to operate the entire PWR fuel cycle with constant pH 300C at the favored value of 7.2-7.4. The use of Enriched Boric Acid (with ∼40% 10B instead of ∼ 20% in natural boron) consequently provides many advantages in enhancing operational safety and life time of several components, as well as facilitating dose rate reduction programs in PWRs and VVER Nuclear Power Plants. When lowering the total boron concentration in the primary coolant, it is possible to minimize: - dose rates during maintenance activities - optimal pH T from the beginning of the fuel cycle (BOC) can mitigate corrosion products that become activated; - the risk of corrosion of various materials of the Reactor Coolant System - allowing a lower lithium (or potassium) concentration mainly at BOC; the sensitive materials are fuel cladding (zirconium alloy), stainless steels (AISI 304 type), nickel-based Alloy 600; - the risk of Axial Offset Anomalies - resulting from precipitation of boron

  19. Remnant Trees in Enrichment Planted Gaps in Quintana Roo, Mexico: Reasons for Retention and Effects on Seedlings

    Directory of Open Access Journals (Sweden)

    Angélica Navarro-Martínez

    2017-07-01

    Full Text Available Natural forest management in the tropics is often impeded by scarcity of advanced regeneration of commercial species. To supplement natural regeneration in a forest managed by a community in the Selva Maya of Mexico, nursery-grown Swietenia macrophylla seedlings were planted in multiple-tree felling gaps, known as bosquetes. Remnant trees are often left standing in gaps for cultural and economic reasons or due to their official protected status. We focus on these purposefully retained trees and their impacts on planted seedlings. Sampled bosquetes were 400–1800 m2, of which remnant trees covered a mean of 29%. Seedling height growth rates over the first 18 months after out-planting more than doubled with increased canopy openness from 0.09 m year−1 under medium cover to 0.22 m year−1 in full sun. Liana infestations and shoot tip damage were most frequent on seedlings in the open, but, contrary to our expectations, height growth rates were 0.14 m year−1 faster for liana-infested seedlings than non-infested and did not differ between damaged and undamaged seedlings. Apparently the more rapid height growth of well-illuminated seedlings more than compensated for the effects of lianas or shoot tip damage. Despite the abundance of remnant trees and their negative effects on seedling growth, enrichment planting in bosquetes has potential for community-based natural forest management in the tropics in supplementing natural regeneration of commercial species. One obvious recommendation is to leave fewer remnant trees, especially those of commercial species that are non-merchantable due to stem defects and trees retained for no apparent reason, which together constituted half of the remnant crown cover in the sampled bosquetes. Finally, given the rapid growth of lianas and understory palms in large canopy gaps, at least the most vigorous of the planted seedlings should be tended for at least two years.

  20. Optimization and comparative analysis of plant organellar DNA enrichment methods suitable for next generation sequencing

    Science.gov (United States)

    Plant organellar genomes contain large repetitive elements that may undergo pairing or recombination to form complex structures and/or sub-genomic fragments. Organellar genomes also exist in admixtures within a given cell or tissue type (heteroplasmy) and abundance of sub-types may change through de...

  1. Methods of forming boron nitride

    Science.gov (United States)

    Trowbridge, Tammy L; Wertsching, Alan K; Pinhero, Patrick J; Crandall, David L

    2015-03-03

    A method of forming a boron nitride. The method comprises contacting a metal article with a monomeric boron-nitrogen compound and converting the monomeric boron-nitrogen compound to a boron nitride. The boron nitride is formed on the same or a different metal article. The monomeric boron-nitrogen compound is borazine, cycloborazane, trimethylcycloborazane, polyborazylene, B-vinylborazine, poly(B-vinylborazine), or combinations thereof. The monomeric boron-nitrogen compound is polymerized to form the boron nitride by exposure to a temperature greater than approximately 100.degree. C. The boron nitride is amorphous boron nitride, hexagonal boron nitride, rhombohedral boron nitride, turbostratic boron nitride, wurzite boron nitride, combinations thereof, or boron nitride and carbon. A method of conditioning a ballistic weapon and a metal article coated with the monomeric boron-nitrogen compound are also disclosed.

  2. Characterization of boron tolerant bacteria isolated from a fly ash dumping site for bacterial boron remediation.

    Science.gov (United States)

    Edward Raja, Chellaiah; Omine, Kiyoshi

    2013-08-01

    Boron is an essential micronutrient for plants, but can above certain concentrations be toxic to living organisms. A major environmental concern is the removal of boron from contaminated water and fly ash. For this purpose, the samples were collected from a fly ash dumping site, Nagasaki prefecture, Japan. The chemical characteristics and heavy metal concentration of the samples were performed by X-ray fluorescent analysis and leaching test. For bacterial analysis, samples were collected in sterile plastic sheets and isolation was carried out by serial dilution method. The boron tolerant isolates that showed values of maximum inhibitory concentration toward boron ranging from 100 to 260 mM level were screened. Based on 16S rRNA sequencing and phylogenetic analysis, the isolates were most closely related to the genera Bacillus, Lysinibacillus, Microbacterium and Ralstonia. The boron tolerance of these strains was also associated with resistant to several heavy metals, such as As (III), Cr (VI), Cd, Cu, Pb, Ni, Se (III) and Zn. Indeed, these strains were arsenic oxidizing bacteria confirmed by silver nitrate test. These strains exhibited their salt resistances ranging from 4 to 15 % were determined in Trypticase soy agar medium. The boron tolerant strains were capable of removing 0.1-2.0 and 2.7-3.7 mg l(-1) boron from the medium and fly ash at 168 h. Thus, we have successfully identified the boron tolerant and removal bacteria from a fly ash dumping site for boron remediation.

  3. pH dependent salinity-boron interactions impact yield, biomass, evapotranspiration and boron uptake in broccoli (Brassica oleracea L.)

    Science.gov (United States)

    Soil pH is known to influence many important biochemical processes in plants and soils, however its role in salinity - boron interactions affecting plant growth and ion relations has not been examined. The purpose of this research was to evaluate the interactive effects of salinity, boron and soil ...

  4. Photosynthesis and growth responses of mustard (Brassica juncea L. cv Pusa Bold) plants to free air carbon dioxide enrichment (FACE).

    Science.gov (United States)

    Ruhil, Kamal; Sheeba; Ahmad, Altaf; Iqbal, Muhammad; Tripathy, Baishnab C

    2015-07-01

    Increased atmospheric [CO2] is likely to affect photosynthesis, plant growth, and yield potential of plants. Mustard (Brassica juncea L.) is an important oil seed crop that is widely grown in India. Therefore, the impact of elevated [CO2] (585 μmol mol(-1)) on pigment and protein content, chlorophyll a fluorescence, photosynthetic electron transport reactions, CO2 assimilation, biomass production, and seed yield potential was measured in B. juncea cv Pusa Bold, grown inside free air carbon dioxide enrichment (FACE) rings installed on the campus of Jawaharlal Nehru University, New Delhi, India. Plants were grown for three consecutive winter seasons (2010-2013), in ambient (385 μmol mol(-1)) or elevated [CO2], in field conditions. Elevated [CO2] had no significant effect on the minimal chlorophyll fluorescence (F 0), while the quantum efficiency of Photosystem II, measured as variable fluorescence (F v = F m-F 0) to maximum fluoresence (F m), increased by 3 %. Electron transport rate, photosystem I, photosystem II, and whole chain electron transport rates increased by 8 % in elevated [CO2]. However, the net photosynthesis rate increased by ≈50 % in three growing seasons under elevated [CO2] condition. The stomatal conductance and transpiration rate decreased resulting in higher photosynthetic water use efficiency. The photosynthesizing surface, i.e., leaf area index substantially increased leading to higher biomass and seed yield under elevated [CO2] condition. Acclimatory downregulation of photosynthesis and plant productivity was not observed in three consecutive growing years suggesting that in the absence of nutrient limitation, B. juncea is highly responsive to elevated CO2 whose yield potential shall increase in changing climatic conditions.

  5. Effect of the enriched filter pie with natural phosphate and microorganisms on soil and plant in a Vermelho-Distrófico Latossolo

    Directory of Open Access Journals (Sweden)

    Leónides Castellanos González

    2016-03-01

    Full Text Available The objective of the research was to evaluate the use of filter pie and phosphate rock enriched with biofertilizer microorganisms on the population of microorganisms and phosphorus tenor in the soil and on plants. The experiment was conducted in a vegetation house with corn plants with Latossolo Red-Distrófico, containing seven treatments disposed in an entirely randomized design, where the treatments were: soil samples and filter pie with additions of phosphate of Araxá rock enriched with microorganisms coming from Biopack (1, Embrafos (2 and Azotofos (3, and without enrichment with microorganisms (4, and three controls, soil just with filter pie (5, soil just with phosphate rock (6 and only soil (7, with three repetitions. Height, stem diameter and number of leaves for plants were evaluated at 14, 28 and 42 days. At the 45 days the dry matters of leafs and roots were evaluated, as the same as populations of the microorganisms and phosphorus tenor in the soil and in the aerial part of the plant. The tenor of soluble phosphorus in the soil and accumulated phosphorous in the aerial part of corn plan were increased by the treatments with filter pie but not higher with filter pie enriched with biofertilizers, so its use isn’t justified. The pie treatments increase the fungus, total and solubilizers bacterial populations in the soil, provoking an increase of the height, diameter, number of leaves and dry matter of corn plants in a Red-Distrófico Latossolo.

  6. Characterization of Oxidative Stability of Fish Oil- and Plant Oil-Enriched Skimmed Milk

    DEFF Research Database (Denmark)

    Saga, Linda C.; Kristinova, Vera; Kirkhus, Bente

    2013-01-01

    oil was added to fish oil in only 5 and 10 %, whereas no protective effect of camelina oil was observed when evaluated by these methods. Moreover, fish oil blended with oat oil conferred the lowest PV and lower amounts of volatile compounds during the storage period of 14 days at 4 °C. Surprisingly......The objective of this research was to determine the oxidative stability of fish oil blended with crude plant oils rich in naturally occurring antioxidants, camelina oil and oat oil, respectively, in bulk and after supplementation of 1 wt% of oil blends to skimmed milk emulsions. Ability of crude...

  7. Response of vegetation to carbon dioxide. Growth, yield and plant water relationships in sweet potatoes in response to carbon dioxide enrichment 1986

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-08-01

    In the summer of 1985, under the joint program of US Department of Energy, Carbon Dioxide Division, and Tuskegee University, experiments were conducted to study growth, yield, photosynthesis and plant water relationships in sweet potato plants growth in an enriched CO{sub 2} environment. The main experiment utilized open top chambers to study the effects of CO{sub 2} and soil moisture on growth, yield and photosynthesis of field-grown plants. In addition, potted plants in open top chambers were utilized in a study of the effects of different CO{sub 2} concentrations on growth pattern, relative growth rate, net assimilation rate and biomass increment at different stages of development. The interaction effects of enriched CO{sub 2} and water stress on biomass production, yield, xylem potential, and stomatal conductance were also investigated. The overall results of the various studies are described.

  8. Plant species' origin predicts dominance and response to nutrient enrichment and herbivores in global grasslands.

    Science.gov (United States)

    Seabloom, Eric W; Borer, Elizabeth T; Buckley, Yvonne M; Cleland, Elsa E; Davies, Kendi F; Firn, Jennifer; Harpole, W Stanley; Hautier, Yann; Lind, Eric M; MacDougall, Andrew S; Orrock, John L; Prober, Suzanne M; Adler, Peter B; Anderson, T Michael; Bakker, Jonathan D; Biederman, Lori A; Blumenthal, Dana M; Brown, Cynthia S; Brudvig, Lars A; Cadotte, Marc; Chu, Chengjin; Cottingham, Kathryn L; Crawley, Michael J; Damschen, Ellen I; Dantonio, Carla M; DeCrappeo, Nicole M; Du, Guozhen; Fay, Philip A; Frater, Paul; Gruner, Daniel S; Hagenah, Nicole; Hector, Andy; Hillebrand, Helmut; Hofmockel, Kirsten S; Humphries, Hope C; Jin, Virginia L; Kay, Adam; Kirkman, Kevin P; Klein, Julia A; Knops, Johannes M H; La Pierre, Kimberly J; Ladwig, Laura; Lambrinos, John G; Li, Qi; Li, Wei; Marushia, Robin; McCulley, Rebecca L; Melbourne, Brett A; Mitchell, Charles E; Moore, Joslin L; Morgan, John; Mortensen, Brent; O'Halloran, Lydia R; Pyke, David A; Risch, Anita C; Sankaran, Mahesh; Schuetz, Martin; Simonsen, Anna; Smith, Melinda D; Stevens, Carly J; Sullivan, Lauren; Wolkovich, Elizabeth; Wragg, Peter D; Wright, Justin; Yang, Louie

    2015-07-15

    Exotic species dominate many communities; however the functional significance of species' biogeographic origin remains highly contentious. This debate is fuelled in part by the lack of globally replicated, systematic data assessing the relationship between species provenance, function and response to perturbations. We examined the abundance of native and exotic plant species at 64 grasslands in 13 countries, and at a subset of the sites we experimentally tested native and exotic species responses to two fundamental drivers of invasion, mineral nutrient supplies and vertebrate herbivory. Exotic species are six times more likely to dominate communities than native species. Furthermore, while experimental nutrient addition increases the cover and richness of exotic species, nutrients decrease native diversity and cover. Native and exotic species also differ in their response to vertebrate consumer exclusion. These results suggest that species origin has functional significance, and that eutrophication will lead to increased exotic dominance in grasslands.

  9. Assessment of enriched uranium storage safety issues at the Oak Ridge Y-12 Plant

    International Nuclear Information System (INIS)

    1996-08-01

    This document is an assessment of the technical safety issues pertaining to the storage of EU at the Oak Ridge Y-12 Plant. The purpose of the assessment is to serve as the basis for defining the technical standards for storage of EU at Y-12. A formal assessment of the Y-12 materials acceptance criteria for EU is currently being conducted by a task force cochaired by B. G. Eddy of DOE Oak Ridge Operations and S. 0. Cox of Y-12 Defense Programs. The mission of this technical assessment for storage is obviously dependent on results of the acceptance assessment. Clearly, the two efforts require coordination to avoid inconsistencies. In addition, both these Assessments must be consistent with the Environmental Assessment for EU storage at Y-12.1 Both the Storage Assessment and the Criteria for Acceptance must take cognizance of the fact that a portion of the EU to be submitted for storage in the future is expected to be derived from foreign sources and to include previously irradiated uranium containing significant levels of transuranics, radioactive daughter products, and unstable uranium isotopes that do not occur in the EU stream of the DOE weapons complex. National security considerations may dictate that these materials be accepted despite the fact that they fail to conform to the Acceptance Criteria. This document will attempt to address the complexities inherent in this situation

  10. Assessment of enriched uranium storage safety issues at the Oak Ridge Y-12 Plant

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-08-01

    This document is an assessment of the technical safety issues pertaining to the storage of EU at the Oak Ridge Y-12 Plant. The purpose of the assessment is to serve as the basis for defining the technical standards for storage of EU at Y-12. A formal assessment of the Y-12 materials acceptance criteria for EU is currently being conducted by a task force cochaired by B. G. Eddy of DOE Oak Ridge Operations and S. 0. Cox of Y-12 Defense Programs. The mission of this technical assessment for storage is obviously dependent on results of the acceptance assessment. Clearly, the two efforts require coordination to avoid inconsistencies. In addition, both these Assessments must be consistent with the Environmental Assessment for EU storage at Y-12.1 Both the Storage Assessment and the Criteria for Acceptance must take cognizance of the fact that a portion of the EU to be submitted for storage in the future is expected to be derived from foreign sources and to include previously irradiated uranium containing significant levels of transuranics, radioactive daughter products, and unstable uranium isotopes that do not occur in the EU stream of the DOE weapons complex. National security considerations may dictate that these materials be accepted despite the fact that they fail to conform to the Acceptance Criteria. This document will attempt to address the complexities inherent in this situation.

  11. Safeguards Guidance Document for Designers of Commercial Nuclear Facilities: International Nuclear Safeguards Requirements and Practices For Uranium Enrichment Plants

    Energy Technology Data Exchange (ETDEWEB)

    Robert Bean; Casey Durst

    2009-10-01

    This report is the second in a series of guidelines on international safeguards requirements and practices, prepared expressly for the designers of nuclear facilities. The first document in this series is the description of generic international nuclear safeguards requirements pertaining to all types of facilities. These requirements should be understood and considered at the earliest stages of facility design as part of a new process called “Safeguards-by-Design.” This will help eliminate the costly retrofit of facilities that has occurred in the past to accommodate nuclear safeguards verification activities. The following summarizes the requirements for international nuclear safeguards implementation at enrichment plants, prepared under the Safeguards by Design project, and funded by the U.S. Department of Energy (DOE) National Nuclear Security Administration (NNSA), Office of NA-243. The purpose of this is to provide designers of nuclear facilities around the world with a simplified set of design requirements and the most common practices for meeting them. The foundation for these requirements is the international safeguards agreement between the country and the International Atomic Energy Agency (IAEA), pursuant to the Treaty on the Non-proliferation of Nuclear Weapons (NPT). Relevant safeguards requirements are also cited from the Safeguards Criteria for inspecting enrichment plants, found in the IAEA Safeguards Manual, Part SMC-8. IAEA definitions and terms are based on the IAEA Safeguards Glossary, published in 2002. The most current specification for safeguards measurement accuracy is found in the IAEA document STR-327, “International Target Values 2000 for Measurement Uncertainties in Safeguarding Nuclear Materials,” published in 2001. For this guide to be easier for the designer to use, the requirements have been restated in plainer language per expert interpretation using the source documents noted. The safeguards agreement is fundamentally a

  12. Impact of Long-Term Forest Enrichment Planting on the Biological Status of Soil in a Deforested Dipterocarp Forest in Perak, Malaysia

    Directory of Open Access Journals (Sweden)

    D. S. Karam

    2012-01-01

    Full Text Available Deforestation leads to the deterioration of soil fertility which occurs rapidly under tropical climates. Forest rehabilitation is one of the approaches to restore soil fertility and increase the productivity of degraded areas. The objective of this study was to evaluate and compare soil biological properties under enrichment planting and secondary forests at Tapah Hill Forest Reserve, Perak after 42 years of planting. Both areas were excessively logged in the 1950s and left idle without any appropriate forest management until 1968 when rehabilitation program was initiated. Six subplots (20 m × 20 m were established within each enrichment planting (F1 and secondary forest (F2 plots, after which soil was sampled at depths of 0–15 cm (topsoil and 15–30 cm (subsoil. Results showed that total mean microbial enzymatic activity, as well as biomass C and N content, was significantly higher in F1 compared to F2. The results, despite sample variability, suggest that the rehabilitation program improves the soil biological activities where high rate of soil organic matter, organic C, N, suitable soil acidity range, and abundance of forest litter is believed to be the predisposing factor promoting higher population of microbial in F1 as compared to F2. In conclusion total microbial enzymatic activity, biomass C and biomass N evaluation were higher in enrichment planting plot compared to secondary forest. After 42 years of planting, rehabilitation or enrichment planting helps to restore the productivity of planted forest in terms of biological parameters.

  13. Boron nitride converted carbon fiber

    Science.gov (United States)

    Rousseas, Michael; Mickelson, William; Zettl, Alexander K.

    2016-04-05

    This disclosure provides systems, methods, and apparatus related to boron nitride converted carbon fiber. In one aspect, a method may include the operations of providing boron oxide and carbon fiber, heating the boron oxide to melt the boron oxide and heating the carbon fiber, mixing a nitrogen-containing gas with boron oxide vapor from molten boron oxide, and converting at least a portion of the carbon fiber to boron nitride.

  14. NEW ADVANCES IN BORON SOIL CHEMISTRY - Paper

    Science.gov (United States)

    Boron is an essential plant micronutrient for which the range between deficiency and toxicity is narrower than for any other nutrient element. Plants respond directly to the amount of B in soil solution and only indirectly to the amount of B adsorbed on soil particle surfaces. ...

  15. NEW ADVANCES IN BORON SOIL CHEMISTRY

    Science.gov (United States)

    Boron is an essential plant micronutrient for which the range between deficiency and toxicity is narrower than for any other nutrient element. Plants respond directly to the amount of B in soil solution and only indirectly to the amount of B adsorbed on soil particle surfaces. ...

  16. Recent ORNL experience in site performance prediction: the Gas Centrifuge Enrichment Plant and the Oak Ridge Central Waste Disposal Facility

    International Nuclear Information System (INIS)

    Pin, F.G.

    1985-01-01

    The suitability of the Portsmouth Gas Centrifuge Enrichment Plant Landfill and the Oak Ridge, Tennessee, Central Waste Disposal Facility for disposal of low-level radioactive waste was evaluated using pathways analyses. For these evaluations, a conservative approach was selected; that is, conservatism was built into the analyses when assumptions concerning future events had to be made or when uncertainties concerning site or waste characteristics existed. Data from comprehensive laboratory and field investigations were used in developing the conceptual and numerical models that served as the basis for the numerical simulations of the long-term transport of contamination to man. However, the analyses relied on conservative scenarios to describe the generation and migration of contamination and the potential human exposure to the waste. Maximum potential doses to man were calculated and compared to the appropriate standards. Even under this conservative framework, the sites were found to provide adequate buffer to persons outside the DOE reservations and conclusions concerning site capacity and site acceptability were drawn. Our experience through these studies has shown that in reaching conclusions in such studies, some consideration must be given to the uncertainties and conservatisms involved in the analyses. Analytical methods to quantitatively assess the probability of future events to occur and to quantitatively determine the sensitivity of the results to data uncertainty may prove useful in relaxing some of the conservatism built into the analyses. The applicability of such methods to pathways analyses is briefly discussed

  17. Application of the HGSYSTEM/UF6 model to simulate atmospheric dispersion of UF6 releases from uranium enrichment plants

    International Nuclear Information System (INIS)

    Goode, W.D. Jr.; Bloom, S.G.; Keith, K.D. Jr.

    1995-01-01

    Uranium hexafluoride is a dense, reactive gas used in Gaseous Diffusion Plants (GDPs) to make uranium enriched in the 235 U isotope. Large quantities of UF 6 exist at the GDPs in the form of in-process gas and as a solid in storage cylinders; smaller amounts exist as hot liquid during transfer operations. If liquid UF 6 is released to the environment, it immediately flashes to a solid and a dense gas that reacts rapidly with water vapor in the air to form solid particles of uranyl fluoride and hydrogen fluoride gas. Preliminary analyses were done on various accidental release scenarios to determine which scenarios must be considered in the safety analyses for the GDPS. These scenarios included gas releases due to failure of process equipment and liquid/gas releases resulting from a breach of transfer piping from a cylinder. A major goal of the calculations was to estimate the response time for mitigating actions in order to limit potential off-site consequences of these postulated releases. The HGSYSTEM/UF 6 code was used to assess the consequences of these release scenarios. Inputs were developed from release calculations which included two-phase, choked flow followed by expansion to atmospheric pressure. Adjustments were made to account for variable release rates and multiple release points. Superpositioning of outputs and adjustments for exposure time were required to evaluate consequences based on health effects due to exposures to uranium and HF at a specific location

  18. Uranium enrichment in South Africa: from the world-unique Z-plant to the use of high-technology lasers

    International Nuclear Information System (INIS)

    McDowell, M.W.

    1995-01-01

    A historical discussion of the technology used in South Africa for the enrichment of uranium, as well as other technological spin-offs for the country that followed from the construction of the Z-plant. The national energy strategy and objectives of the government during the Apartheid years resulted in the development of several large-scale energy projects. The pressure of sanctions forced the Z-plant to be rushed into operation at an uneconomical capacity of 250 000 SWU per annum. In 1994 this implied that enriched uranium was produced at a cost of $200 per SWU while the world market price was below $90. While the production of enriched uranium at the Z-plant ceased early in 1995, the expertise gained will not be lost entirely. As a result of the high energy and financial capital intensive current methods of producing enriched uranium, research started in the early 1970's into alternative production processes making use of lasers. South Africa has opted for the MLIS (molecular laser isotope separation) process, as a result of its vast experience gained from the Z-plant in the handling of the molecular input gas UF6 (uranium hexafluoride), and this has been under development since the early 1980's. During 1994 significant progress was made with MLIS, in particular with single-step enrichment from natural uranium to better than 4% uranium 235 on a macro scale. The Atomic Energy Corporation of South Africa's strategy is to licence the process internationally. 3 tabs., 3 figs

  19. [Preventive effects of 4 Se-enriched plants on rat stomach cancer induced by MNNG--3. Se accumulation and distribution in rats of different selenium resources for prevention of stomach cancer].

    Science.gov (United States)

    Yang, Wenije; Chen, Jing; Li, Weidong; Chen, Xiaobin

    2008-07-01

    To investigate the accumulation and distribution of blood and tissue Se in rats with long-term and high-dose of Se supplementation by four Se-enriched plants (Se-enriched garlic, Se-enriched broccoli, Se-enriched green kale and Se-enriched red kale) in the N-methyl-N'-nitro-N-nitrosoguanidine (MNNG)-induced stomach cancer model. Ninety rats were fed by basal diet for a week, divided equally into the control, MNNG and seven Se supplementation groups. Rats were daily given 15 mg/kg bw of MNNG for ten days except those in the control group, and rats in five Se-enriched plant treatment groups were daily given 150 or 300 microg Se/kg of bw of the plant suspension by gavage for 17 weeks. Rats were sacrificed at the end of 18th week, the Se contents of blood, red blood cell, plasma, liver, kidney, spleen, heart, brain and testicle were determined. The Se contents of liver and kidney in rats supplemented by Se-enriched garlic were significantly lower than those in rats supplemented by Se-enriched broccoli and two Se-enriched kales, and the Se contents of red blood cell and spleen higher than those in rats supplemented by Se-enriched broccoli and two Se-enriched kales. The data primarily shows that the differences of the accumulation and distribution of blood and tissue Se in rats are related to the supplemented plant Se components, and that lower Se accumulation of the liver and kidney in rats supplemented by Se-enriched garlic than by other plants may be one of Se safety indices of Se-enriched garlic.

  20. [Preventive effects of 4 Se-enriched plants on rat stomach cancer induced by MNNG 2. Safety of different selenium resources for prevention of stomach cancer].

    Science.gov (United States)

    Yang, Wenjie; Chen, Jing; Li, Weidong; Chen, Xiaobin

    2008-01-01

    To guide the application of selenium (Se) in the prevention of human chronic diseases, the safety of different Se resources (selenite, Se-enriched garlic, Se-enriched broccoli, Se-enriched green kale and Se-enriched red kale) was investigated. Ninety rats were fed the basal diet for a week, divided equally into the control, N-methyl- N'-nitro-N-nitrosoguanidine (MNNG) and seven Se treatment groups. Rats were daily given 15 mg/kg bw of MNNG for ten days except those in the control group, and rats in seven Se supplementation groups were daily given 75 microg/kg bw or 150 microg/kg bw sodium selenite solution, 150 or 300 microg/kg bw Se as of Se-enriched plant suspension by gavage for 17 weeks. Rats were sacrificed at the end of 18th week, the liver glutathione S-transferase (GST), serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities were detected. Rats were given with the basal diet and water freely during the experiment. The data was statistically analyzed by SPSS 12.0 software. All rats in Se 75 microg/kg bw of Se as sodium selenite group died within 6 weeks, the body weights of rats in 75 microg/kg bw of Se as sodium selenite group were significantly lower than those of rats in other groups, the serum AST and ALT activities of rats in 75 microg/kg bw of Se as sodium selenite group were significantly higher than those of rats in other groups, and only the Se supplementation of 75 microg/kg bw of Se as selenite led to rat liver pathological change. Selenite is at least 4 times as toxic as Se-enriched higher plants selected in this experiment.

  1. 10 CFR Appendix D to Part 110 - Illustrative List of Aerodynamic Enrichment Plant Equipment and Components Under NRC Export...

    Science.gov (United States)

    2010-01-01

    ... enrichment process by compressing and converting UF6 to a liquid or solid form; and (iv) “Product” or “tails... Export Licensing Authority Note—In aerodynamic enrichment processes, a mixture of gaseous UF6 and light... quantities can provide an important indication of end use. Because aerodynamic processes use UF6, all...

  2. Removal of Boron from Waste Waters by Ion- Exchange in a Batch System

    OpenAIRE

    Pelin Demirçivi; Gülhayat Nasün-Saygılı

    2008-01-01

    Boron minerals are very useful for various industrial activities, such as glass industry and detergent industry, due to its mechanical and chemical properties. During the production of boron compounds, many of these are introduced into the environment in the form of waste. Boron is also an important micro nutrient for the plants to vegetate but if it exists in high concentrations, it could have toxic effects. The maximum boron level in drinking water for human health is g...

  3. Boron removal from saline water by a microbial desalination cell integrated with donnan dialysis

    OpenAIRE

    Ping, Q.; Abu-Reesh, I.M.; He, Z.

    2015-01-01

    Boron has toxic effects on plant growth and thus its removal is necessary from desalinated saline water for irrigation application. Microbial desalination cells (MDCs) are a new approach for effective desalination but boron removal has not been addressed before. Herein, MDCs were studied for boron removal with aid of Donnan Dialysis (DD). The alkaline solution generated by the MDC cathode was used to ionize boric acid to facilitate boron removal. An MDC system with DD pretreatment removed 60 ...

  4. High performance ligands for the removal of aqueous boron species by continuous polymer enhanced ultrafiltration

    OpenAIRE

    Yürüm, Alp; Yurum, Alp; Taralp, Alpay; Bıçak, Niyazi; Bicak, Niyazi; Özbelge, Hilmi Önder; Ozbelge, Hilmi Onder; Yılmaz, Levent; Yilmaz, Levent

    2013-01-01

    Boron is an essential element for plant growth, but it may also result in toxicity when present in excessive amounts. In this study, continuous polymer enhanced ultrafiltration (PEUF) was developed to selectively recover aqueous boron species (collectively termed “boron” hereafter) from solution. The PEUF process consisted of complexing boron to a water-soluble polymer, removing all non-complexed solutes by UF, restoring the unloaded polymer, and isolating the newly freed boron by UF. Three d...

  5. Boron- and salt-tolerant trees and shrubs for northern Nevada

    Science.gov (United States)

    Heidi Kratsch

    2012-01-01

    Boron is a mineral that, in small quantities, is essential for plant growth and development , but becomes toxic at levels above 0.5 to 1 part per million (ppm) in the soil. Excess boron may be naturally present in the soil, and it can accumulate by irrigating with water high in boron. Boron occurs naturally in arid soils originating from geologically young deposits. It...

  6. Reclamation of abandoned ash pond of Neyveli thermal power plant by enrichment and its effect on growth and yield of gingelly

    Energy Technology Data Exchange (ETDEWEB)

    Sheela, A.M.; Shanmugasundaram, R.; Sundaram, M.D. [Annamalai Nagar University, Annamalai, Nagar (India). Dept. of Microbiology

    2003-07-01

    Ash ponds are the common disposal sites of ash generated from India's thermal power stations. An attempt was made to enrich the ash pond of Neyveli Lignite Corporation Ltd., Neyveli, using organic amendments and microbial inoculants to promote crop growth. The oil seed crop gingelly was grown in two seasons and more growth and yield was recorded in the second crop, which was enriched in the second time also. The inoculation effect of the crop with VAM fungus Glomus mosseae and the acid-tolerant Azospirillum isolate, A. lipoferum PAI-1 was studied. The co-inoculation of Azospirillum with VAM enhanced the rhizosphere dehydrogenase enzyme activity, growth, yield, N, and P content of the plant in the enriched ash pond. Hence, the nutritionally and biologically poor medium like ash ponds could be enriched successively to increase in the nutrient contents and microbial activity. Prolonged enrichment would be providing favourable conditions for the establishment of vegetation and the environmental pollution is greatly reduced by the vegetative cover on barren land. 30 refs., 6 tabs.

  7. Nothing Boring About Boron

    Science.gov (United States)

    Pizzorno, Lara

    2015-01-01

    The trace mineral boron is a micronutrient with diverse and vitally important roles in metabolism that render it necessary for plant, animal, and human health, and as recent research suggests, possibly for the evolution of life on Earth. As the current article shows, boron has been proven to be an important trace mineral because it (1) is essential for the growth and maintenance of bone; (2) greatly improves wound healing; (3) beneficially impacts the body’s use of estrogen, testosterone, and vitamin D; (4) boosts magnesium absorption; (5) reduces levels of inflammatory biomarkers, such as high-sensitivity C-reactive protein (hs-CRP) and tumor necrosis factor α (TNF-α); (6) raises levels of antioxidant enzymes, such as superoxide dismutase (SOD), catalase, and glutathione peroxidase; (7) protects against pesticide-induced oxidative stress and heavy-metal toxicity; (8) improves the brains electrical activity, cognitive performance, and short-term memory for elders; (9) influences the formation and activity of key biomolecules, such as S-adenosyl methionine (SAM-e) and nicotinamide adenine dinucleotide (NAD+); (10) has demonstrated preventive and therapeutic effects in a number of cancers, such as prostate, cervical, and lung cancers, and multiple and non-Hodgkin’s lymphoma; and (11) may help ameliorate the adverse effects of traditional chemotherapeutic agents. In none of the numerous studies conducted to date, however, do boron’s beneficial effects appear at intakes > 3 mg/d. No estimated average requirements (EARs) or dietary reference intakes (DRIs) have been set for boron—only an upper intake level (UL) of 20 mg/d for individuals aged ≥ 18 y. The absence of studies showing harm in conjunction with the substantial number of articles showing benefits support the consideration of boron supplementation of 3 mg/d for any individual who is consuming a diet lacking in fruits and vegetables or who is at risk for or has osteopenia; osteoporosis

  8. Efeitos do boro em algodoeiro cultivado em condições de casa de vegetação Effects of boron application to cotton plant in a greenhouse study

    Directory of Open Access Journals (Sweden)

    Nelson M. da Silva

    1979-01-01

    Full Text Available Visando obter subsídios para a instalação de futuros ensaios de campo com adubação boratada do algodoeiro, foi conduzido estudo em casa de vegetação, utilizando-se solo comprovadamente carente em boro para essa cultura. Foram usadas doses de 0, 133, 266 e 532mg de bórax por vaso contendo 5,0kg de terra. Em vasos extras, estudaram-se níveis mais elevados do produto. O efeito de boro sobre a altura média das plantas, peso de capulho, peso de sementes e comprimento de fibra foi significativo estatisticamente e de natureza quadrática. A concentração de B na matéria seca da parte aérea da planta ou da folha cresceu em proporção à dose utilizada. No caso da análise de folhas de plantas carentes, a concentração variou de 10 a 39ppm, com média de 19pmm de B, enquanto em plantas com grave sintoma de toxicidade foi obtido índice superior a 590ppm de B. Em plantas com carência de boro foi observado um ou vários dos seguintes sintomas: paralisação de crescimento, superbrotamento, intumescimento de nós com escurecimento de tecido, deformações do limbo e do pecíolo de cotilédones e de folhas verdadeiras, anéis concêntricos com necroses correspondentes da medula de pecíolos foliares e deformações das flores. Como sintoma de toxicidade, observou-se clorose marginal e internerval do cotilédone e/ou da folha verdadeira, que evoluiu ou não para necrose do tecido, permanecendo as nervuras com coloração verde normal.A greenhouse experiment of borax application to cotton cultivated on a boron deficient soil, was conducted in order to obtain data for development of future field trials. Borax was applied to pot containing 5,0kg of soil in amounts of 0, 133, 266 e 532mg. Additional treatments with higher levels of boron was applied to extra pots. The influence of boron on plant height, weight of bolls and seeds and on fiber lenght was statistically significant and of quadratic nature. The content of boron, determined either in

  9. Finding of no significant impact: Interim storage of enriched uranium above the maximum historical level at the Y-12 Plant Oak Ridge, Tennessee

    International Nuclear Information System (INIS)

    1995-01-01

    The US Department of Energy (DOE) has prepared an Environmental Assessment (EA) for the Proposed Interim Storage of Enriched Uranium Above the Maximum Historical Storage Level at the Y-12 Plant, Oak Ridge, Tennessee (DOE/EA-0929, September, 1994). The EA evaluates the environmental effects of transportation, prestorage processing, and interim storage of bounding quantities of enriched uranium at the Y-12 Plant over a ten-year period. The State of Tennessee and the public participated in public meetings and workshops which were held after a predecisional draft EA was released in February 1994, and after the revised pre-approval EA was issued in September 1994. Comments provided by the State and public have been carefully considered by the Department. As a result of this public process, the Department has determined that the Y-12 Plant-would store no more than 500 metric tons of highly enriched uranium (HEU) and no more than 6 metric tons of low enriched uranium (LEU). The bounding storage quantities analyzed in the pre-approval EA are 500 metric tons of HEU and 7,105.9 metric tons of LEU. Based on-the analyses in the EA, as revised by the attachment to the Finding of No Significant Impact (FONSI), DOE has determined that interim storage of 500 metric tons of HEU and 6 metric tons of LEU at the Y-12 Plant does not constitute a major Federal action significantly affecting the quality of the human environment, within the meaning of the National Environmental Policy Act (NEPA) of 1969. Therefore, an Environmental Impact Statement (EIS) is not required and the Department is issuing this FONSI

  10. Promotion of uranium enrichment business

    International Nuclear Information System (INIS)

    Kurushima, Morihiro

    1981-01-01

    The Committee on Nuclear Power has studied on the basic nuclear power policy, establishing its five subcommittees, entrusted by the Ministry of Nternational Trade and Industry. The results of examination by the subcommittee on uranium enrichment business are given along with a report in this connection by the Committee. In order to establish the nuclear fuel cycle, the aspect of uranium enrichment is essential. The uranium enrichment by centrifugal process has proceeded steadily in Power Reactor and Nuclear Fuel Development Corporation. The following matters are described: the need for domestic uranium enrichment, the outlook for overseas enrichment services and the schedule for establishing domestic enrichment business, the current state of technology development, the position of the prototype enrichment plant, the course to be taken to establish enrichment business the main organization operating the prototype and commercial plants, the system of supplying centrifuges, the domestic conversion of natural uranium the subsidies for uranium enrichment business. (J.P.N.)

  11. Indigenous Carbonaceous Matter and Boron Associated with Halite Crystals in Nakhla

    Science.gov (United States)

    Thomas-Keprta, K. L.; Clemett, S. J.; McKay, D. S.; Gibson, E. K.; Wentworth, S. J.

    2015-01-01

    We report here the observation of indigenous organic matter spatially associated with, and in several cases embedded within, halite crystals located in alteration veins inside the Martian meteorite Nakhla. Further-more, we have also detected enrichments of boron (B) in these halites far in excess of those previously reported in bulk Martian meteorites. Boron in Martian halites has not been detected previously.

  12. The Combined Action of Duplicated Boron Transporters Is Required for Maize Growth in Boron-Deficient Conditions.

    Science.gov (United States)

    Chatterjee, Mithu; Liu, Qiujie; Menello, Caitlin; Galli, Mary; Gallavotti, Andrea

    2017-08-01

    The micronutrient boron is essential in maintaining the structure of plant cell walls and is critical for high yields in crop species. Boron can move into plants by diffusion or by active and facilitated transport mechanisms. We recently showed that mutations in the maize boron efflux transporter ROTTEN EAR (RTE) cause severe developmental defects and sterility. RTE is part of a small gene family containing five additional members ( RTE2 - RTE6 ) that show tissue-specific expression. The close paralogous gene RTE2 encodes a protein with 95% amino acid identity with RTE and is similarly expressed in shoot and root cells surrounding the vasculature. Despite sharing a similar function with RTE , mutations in the RTE2 gene do not cause growth defects in the shoot, even in boron-deficient conditions. However, rte2 mutants strongly enhance the rte phenotype in soils with low boron content, producing shorter plants that fail to form all reproductive structures. The joint action of RTE and RTE2 is also required in root development. These defects can be fully complemented by supplying boric acid, suggesting that diffusion or additional transport mechanisms overcome active boron transport deficiencies in the presence of an excess of boron. Overall, these results suggest that RTE2 and RTE function are essential for maize shoot and root growth in boron-deficient conditions. Copyright © 2017 by the Genetics Society of America.

  13. The ten stages pilot plant: its utilization in the research of the dynamic behavior and regullating process of a jet nozzle cascade for uranium enrichment

    International Nuclear Information System (INIS)

    Yadoya, R.; Camara, A.S.; Consiglio, R.V.; Bley, P.; Hein, H.; Linder, G.

    1986-01-01

    A ten stage pilot plant to study experimentally dynamic behavior of a uranium enrichment plant based on separation nozzle process was developed and constructed at Karlsruhe Nuclear Research Center. This installation was transfered to the Development Center of Nuclear Technology (CDTN) of Nuclebras in Belo Horizonte, Brazil. The separation elements installed have a new design with higher efficiency, Known as double-deflections system. The power plant has been used to improve the control method and to prove the stability of separation nozzle cascade under pertubations produced artificially. The stabilization process of UF 6 quantity in cascade by UF 6 inventory regulation at bottom stage will have practication in the First Cascade, in Rezende, RJ, Brazil and may be uded i emonstration plant. The experimental results have shown to be comparable with those obtained by computer simulation. (Author) [pt

  14. Identification of proteins involved in excess boron stress in roots of ...

    African Journals Online (AJOL)

    Plants are constantly challenged by various biotic and abiotic stresses in nature. Boron toxicity have become one of the important abiotic stress factor for plants. Boron toxicity responses of plants is reflected by alterations in protein expression level, activity, location and concentration. In this study, we identified the proteins ...

  15. Resposta de brócolis, couve-flor e repolho à adubação com boro em solo arenoso Response of boron fertilization on broccoli, cauliflower and cabbage planted in sandy soil

    Directory of Open Access Journals (Sweden)

    Luiz Carlos Pizetta

    2005-03-01

    Full Text Available Foram avaliados em condições de campo, em solo arenoso, com baixo teor de boro, os efeitos da adubação com cinco doses de boro (0; 2; 4; 6 e 8 kg ha-1 de B na forma de bórax na produção de brócolis, couve-flor e repolho. O experimento obedeceu a um esquema fatorial com delineamento experimental de blocos ao acaso com três repetições. As adubações orgânica e química, inclusive o bórax, foram feitas no sulco antes do transplantio das mudas e a colheita foi feita entre 63 e 93 dias após o transplantio. A produtividade de brócolis variou de 16,9 a 20,5 t ha-1; a de couve-flor de 21,6 a 29,6 t ha-1 e a de repolho de 40,5 a 46,4 t ha-1. O aumento observado na produtividade de brócolis e de repolho foi linear e o efeito das doses de boro na produtividade de couve-flor foi quadrático, sendo necessários 5,1 kg ha-1 de B para atingir a produtividade máxima de 30 t ha-1. Brócolis e repolho mostraram-se menos sensíveis do que a couve-flor tanto à deficiência quanto ao excesso de boro. No caso da couve-flor, com a aplicação de 2 kg ha-1 ou de 6 kg ha-1 de B houve significativa perda de qualidade do produto.The effects of boron fertilization on yield of broccoli, cauliflower and cabbage were evaluated through a field experiment carried out on a sandy soil low in available boron. Five boron levels (0; 2; 4; 6; and 8 kg ha-1 B as borax were applied in broccoli, cauliflower and cabbage using a factorial scheme and a randomized block design with three replicates. Organic manure and chemical fertilizers, including borax, were applied in the planting furrow before seedlings transplant and plants were harvested 63 to 93 days after planting date. The yield intervals obtained with broccoli, cauliflower and cabbage varied according to the following intervals: 16.9 to 20.5 t ha-1, 21.6 to 29.6 t ha-1 and 40.5 to 46.3 t ha-1, respectively. The increase in production observed in broccoli and cabbage yield was linear with boron levels and the

  16. The isotopic enrichment of uranium in 1979

    International Nuclear Information System (INIS)

    Baron, M.

    1979-01-01

    The Eurodif uranium enrichment plant built on the Tricastin site is described. The uranium isotope separation plants in service abroad are presented. The main characteristics of the international enrichment market are defined [fr

  17. Differences in Copper Absorption and Accumulation between Copper-Exclusion and Copper-Enrichment Plants: A Comparison of Structure and Physiological Responses.

    Science.gov (United States)

    Fu, Lei; Chen, Chen; Wang, Bin; Zhou, Xishi; Li, Shuhuan; Guo, Pan; Shen, Zhenguo; Wang, Guiping; Chen, Yahua

    2015-01-01

    Differences in copper (Cu) absorption and transport, physiological responses and structural characteristics between two types of Cu-resistant plants, Oenothera glazioviana (Cu-exclusion type) and Elsholtzia haichowensis (Cu-enrichment type), were investigated in the present study. The results indicated the following: (1) After 50 μM Cu treatment, the Cu ratio in the xylem vessels of E. haichowensis increased by 60%. A Cu adsorption experiment indicated that O. glazioviana exhibited greater resistance to Cu, and Cu absorption and the shoot/root ratio of Cu were significantly lower in O. glazioviana than in E. haichowensis. (2) An analysis of the endogenous abscisic acid (ABA) variance and exogenous ABA treatment demonstrated that the ABA levels of both plants did not differ; exogenous ABA treatment clearly reduced Cu accumulation in both plants. (3) The leaf stomatal density of O. glazioviana was significantly less than that of E. haichowensis. Guard cells in E. haichowensis plants were covered with a thick cuticle layer, the epidermal hair was more numerous and longer, and the number of xylem conduits in the root was small. (4) The transpiration rate and the stomatal conductance of O. glazioviana were both significantly lower than those of E. haichowensis, regardless of whether the plants were treated with Cu. Taken together, these results indicate that the differences in the structural characteristics between these two plant species, particularly in the characteristics related to plant transpiration, are important factors that govern whether plants acquire or exclude Cu.

  18. Differences in Copper Absorption and Accumulation between Copper-Exclusion and Copper-Enrichment Plants: A Comparison of Structure and Physiological Responses.

    Directory of Open Access Journals (Sweden)

    Lei Fu

    Full Text Available Differences in copper (Cu absorption and transport, physiological responses and structural characteristics between two types of Cu-resistant plants, Oenothera glazioviana (Cu-exclusion type and Elsholtzia haichowensis (Cu-enrichment type, were investigated in the present study. The results indicated the following: (1 After 50 μM Cu treatment, the Cu ratio in the xylem vessels of E. haichowensis increased by 60%. A Cu adsorption experiment indicated that O. glazioviana exhibited greater resistance to Cu, and Cu absorption and the shoot/root ratio of Cu were significantly lower in O. glazioviana than in E. haichowensis. (2 An analysis of the endogenous abscisic acid (ABA variance and exogenous ABA treatment demonstrated that the ABA levels of both plants did not differ; exogenous ABA treatment clearly reduced Cu accumulation in both plants. (3 The leaf stomatal density of O. glazioviana was significantly less than that of E. haichowensis. Guard cells in E. haichowensis plants were covered with a thick cuticle layer, the epidermal hair was more numerous and longer, and the number of xylem conduits in the root was small. (4 The transpiration rate and the stomatal conductance of O. glazioviana were both significantly lower than those of E. haichowensis, regardless of whether the plants were treated with Cu. Taken together, these results indicate that the differences in the structural characteristics between these two plant species, particularly in the characteristics related to plant transpiration, are important factors that govern whether plants acquire or exclude Cu.

  19. Boron contents and isotope compositions of oceanic crusts from the Oman and Troodos ophiolites

    Science.gov (United States)

    Yamaoka, K.; Matsukura, S.; Ishikawa, T.; Kawahata, H.

    2011-12-01

    Boron is excellent tracer for elucidating crustal recycling in subduction zones because of the high concentration of boron in the upper part of the slab and the high mobility of boron during dehydration of the slab. However, fundamental data for vertical distribution of boron in hydrothermally altered oceanic crust are still limited. In this study, boron contents and isotopic compositions were determined for complete section of the oceanic crusts in the Oman and Troodos ophiolite. Although the boron contents of rocks decreased with depth in both the oceanic crusts, altered rocks from deep section showed obvious boron enrichment relative to fresh rocks. The pillow lavas in the Troodos ophiolite, which have been weathered on the seafloor for ~80 Myrs, was highly enriched in boron (>100 ppm), supporting that boron inventory of pillow lava section strongly depends on the crustal age. The δ11B of rocks in the Oman ophiolite systematically increased with depth and negatively correlate with the δ18O values, suggesting that the δ11B values are essentially controlled by alteration temperature. On the other hand, the δ11B profile in the Troodos ophiolite didn't show clear increase trend. The boron contents for the bulk oceanic crusts of the Oman and Troodos ophiolites are estimated to be 3.6 ppm and 12 ppm, respectively. About 8% of δ11B was estimated for both the bulk oceanic crusts. In contrast to previous views, hydrothermally altered gabbro section can be a large sink of boron. This boron-enriched, high-δ11B lower oceanic crust may impact on the estimate of the δ11B value for fluids librated from the subducted oceanic slab, which is believed to largely control the δ11B values of arc magmas generated in the mantle wedge.

  20. Re-assessment of plant carbon dynamics at the Duke free-air CO2 enrichment site: interactions of atmospheric [CO2] with nitrogen and water availability over stand development

    Science.gov (United States)

    Heather R. McCarthy; Ram Oren; Kurt H Johnsen; Anne Gallet-Budynek; Seth G. Pritchard; Charles W Cook; Shannon L. LaDeau; Robert B. Jackson; Adrien C. Finzi

    2010-01-01

    The potential for elevated [CO2]-induced changes to plant carbon (C) storage, through modifications in plant production and allocation of C among plant pools, is an important source of uncertainty when predicting future forest function. Utilizing 10 yr of data from the Duke free-air CO2 enrichment site, we evaluated the...

  1. Neutron sensitivity improvement in boron-lined proportional counters

    International Nuclear Information System (INIS)

    Dighe, P.M.; Prasad, K.R.; Kataria, S.K.

    2002-01-01

    Various techniques have been employed to improve the neutron sensitivity of boron-coated proportional counters developed indigenously. A boron-lined proportional counter (67 mm ID x 750 mm length) of 17 cps/nv thermal neutron sensitivity is developed by coating 92% enriched 10 B on the inner wall of the counter. This counter can be used for low thermal neutron flux (∼0.2 nv) at various applications such as neutron area monitoring, reactor start-up instrumentation, assay of fissile materials and detection of fuel failure. An improvement in sensitivity was also achieved by summing the output signals from four 10 B lined counters and two BF 3 proportional counters. The summation did not change the susceptibility of the device to gamma interference. In view of the scarcity of enriched 10 B isotope, indigenously available natural boron coated two prototype proportional counters are developed of 0.8 cps/nv and 1.1 cps/nv thermal neutron sensitivity. Efforts have been made to improve the sensitivity with boron coated 3-dimensional structures introduced into the sensitive volume. Tests in thermal neutron flux showed 50% improvement in the sensitivity due to the introduction of additional boron coated wires. Another counter with 51 boron-coated annular discs (23 mm OD X 10 mm ID X 1 mm thick) mounted perpendicular to the axis of the cathode showed 1.7 cps/nv neutron sensitivity, an improvement by a factor of 2.5. (author)

  2. Boron isotopes as an artificial tracer.

    Science.gov (United States)

    Quast, Konrad W; Lansey, Kevin; Arnold, Robert; Bassett, Randy L; Rincon, Martha

    2006-01-01

    A field study was conducted using a combination of intrinsic and artificial tracers to estimate travel times and dilution during transport of infiltrate from a reclaimed water infiltration basin to nearby monitoring wells. A major study objective was to validate boric acid enriched in (10)B as an artificial tracer. Basin 10E at the Rio Hondo Spreading Grounds in Whittier, California, was the site of the test. The basin normally receives a mixture of treated municipal waste water, purchased State Project water, and local runoff from the San Gabriel River. Approximately 3.5 kg of (10)B-enriched boric acid was dispersed among 2.05 x 10(5) m(3) of basin water to initiate the experiment. The resultant median delta(11)B in the infiltration basin was -71 per thousand. Prior to tracer addition, the basin water had an intrinsic delta(11)B of +2 per thousand. Local monitoring wells that were used to assess travel times had delta(11)B values of +5 per thousand and +8 per thousand at the time of tracer addition. Analytic results supported an assumption that boron is conserved during ground water transport and that boron enriched in (10)B is a useful artificial tracer. Several intrinsic tracers were used to reinforce the boric acid tracer findings. These included stable isotopes of oxygen (delta(18)O) and hydrogen (deltaD), sulfate concentration, and the boron to chloride ratio. Xenon isotopes, (136)Xe and (124)Xe, also supported boron isotope results. Xenon isotopes were added to the recharge basin as dissolved gases by investigators from the Lawrence Livermore National Laboratory.

  3. Has the impact of rising CO2 on plants been exaggerated by meta-analysis of free air CO2 enrichment studies?

    Directory of Open Access Journals (Sweden)

    Matthew Haworth

    2016-08-01

    Full Text Available Meta-analysis is extensively used to synthesise the results of free air CO2 enrichment (FACE studies to produce an average effect size, which is then used to model likely plant response to rising [CO2]. The efficacy of meta-analysis is reliant upon the use of data that characterises the range of responses to a given factor. Previous meta-analyses of the effect of FACE on plants have not incorporated the potential impact of reporting bias in skewing data. By replicating the methodology of these meta-analytic studies, we demonstrate that meta-analysis of FACE has likely exaggerated the effect size of elevated [CO2] on plants by 20 to 40%; having significant implications for predictions of food security and vegetation response to climate change. Incorporation of the impact of reporting bias did not affect the significance or the direction of the [CO2] effect.

  4. Designing your boron-charging system

    International Nuclear Information System (INIS)

    Miller, J.

    1979-01-01

    High-pressure positive-displacement pumps used in the boron-charging setups of pressurized-water (PWR) nuclear plants because of their inherently high efficiencies over a wide range of pressures and speeds are described. Hydrogen-saturated water containing 4-12% boric acid is fed to the pump from a volume-control tank under a gas blanket. Complicated piping and the pulsation difficulties associated with reciprocating pumps make hydrogen-saturated boron-charging systems a challenge to the designer. The article describes the unusual hydraulics of the systems to help assure a trouble-free design

  5. Development and application of a new in-line coupling of a miniaturized boronate affinity monolithic column with capillary zone electrophoresis for the selective enrichment and analysis of cis-diol-containing compounds.

    Science.gov (United States)

    Espina-Benitez, Maria Betzabeth; Randon, Jérôme; Demesmay, Claire; Dugas, Vincent

    2017-04-21

    An integrated, miniaturized and fully automated system was developed for the analysis (preconcentration/purification, separation and detection) of cis-diol containing molecules in complex matrices. This innovative in-line coupling system was achieved via the in-situ and localized synthesis of a short segment of silica-based monolith at the inlet of a 75-μm inner diameter fused silica capillary. The monolithic segment was locally functionalized with an acrylamide derivative of phenylboronic acid by free radical photopolymerization within 10min of irradiation time. Efficiency of the photopolymerization reaction was followed by frontal affinity chromatography of 1,2-dihydroxybenzene (catechol) as cis-diol model solute. An active-site amount of 0.43nmolcm -1 (9.8nmolμL -1 ) of phenylboronic acid moieties was obtained, with a K d value of about 290μM close to reported value for the phenyl boronate-catechol complex. The optimal conditions of use of the miniaturized boronate affinity monolithic column (μBAMC) were determined and adapted to the in-line coupling with capillary electrophoresis. Catechol was specifically preconcentrated in a pH 8.5 phosphate buffer/MeOH (80/20, v/v) mixture. A volume up to 20 times the monolith volume can be percolated with a quantitative recovery yield. Three catecholamines were purified, preconcentrated and in-line separated. Elution from the μBAMC was performed with a small plug of acidic solution, allowing field amplified sample stacking of solutes within the plug before their in-line electrophoretic separation at pH 8.75. This unique in-line coupling was successfully used for the fully automated analysis of catecholamines neurotransmitters in urine samples, highlighting the purification efficiency of the μBAMC and the potential of such a fully integrated approach. In addition to the low sample volume required (less than 2μL), the limits of detection (LOD) accomplished with this coupling were estimated at 9.0, 9.5 and 4.8ngmL -1

  6. Long term analysis of the biomass content in the feed of a waste-to-energy plant with oxygen-enriched combustion air.

    Science.gov (United States)

    Fellner, Johann; Cencic, Oliver; Zellinger, Günter; Rechberger, Helmut

    2011-10-01

    Thermal utilization of municipal solid waste and commercial wastes has become of increasing importance in European waste management. As waste materials are generally composed of fossil and biogenic materials, a part of the energy generated can be considered as renewable and is thus subsidized in some European countries. Analogously, CO(2) emissions of waste incinerators are only partly accounted for in greenhouse gas inventories. A novel approach for determining these fractions is the so-called balance method. In the present study, the implementation of the balance method on a waste-to-energy plant using oxygen-enriched combustion air was investigated. The findings of the 4-year application indicate on the one hand the general applicability and robustness of the method, and on the other hand the importance of reliable monitoring data. In particular, measured volume flows of the flue gas and the oxygen-enriched combustion air as well as corresponding O(2) and CO(2) contents should regularly be validated. The fraction of renewable (biogenic) energy generated throughout the investigated period amounted to between 27 and 66% for weekly averages, thereby denoting the variation in waste composition over time. The average emission factor of the plant was approximately 45 g CO(2) MJ(-1) energy input or 450 g CO(2) kg(-1) waste incinerated. The maximum error of the final result was about 16% (relative error), which was well above the error (<8%) of the balance method for plants with conventional oxygen supply.

  7. Combined effects of CO2 enrichment, diurnal light levels and water stress on foliar metabolites of potato plants grown in naturally sunlit controlled environment chambers.

    Science.gov (United States)

    Barnaby, Jinyoung Y; Fleisher, David; Reddy, Vangimalla; Sicher, Richard

    2015-02-01

    Experiments were conducted in outdoor, naturally sunlit, soil-plant-atmosphere research (SPAR) chambers using plants grown in pots. Drought treatments were imposed on potato plants (Solanum tuberosum cv. Kennebec) beginning 10 days after tuber initiation. A total of 23 out of 37 foliar metabolites were affected by drought when measured 11 days after initiating water stress treatments. Compounds that accumulated in response to drought were hexoses, polyols, branched chain amino acids (BCAAs) and aromatic amino acids, such as proline. Conversely, leaf starch, alanine, aspartate and several organic acids involved in respiratory metabolism decreased with drought. Depending upon harvest date, a maximum of 12 and 17 foliar metabolites also responded to either CO2 enrichment or diurnal treatments, respectively. In addition, about 20% of the measured metabolites in potato leaflets were simultaneously affected by drought, CO2 enrichment and diurnal factors combined. This group contained BCAAs, hexoses, leaf starch and malate. Polyols and proline accumulated in response to water stress but did not vary diurnally. Water stress also amplified diurnal variations of hexoses and starch in comparison to control samples. Consequently, specific drought responsive metabolites in potato leaflets were dramatically affected by daily changes of photosynthetic carbon metabolism. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.

  8. Consuming functional foods enriched with plant sterol or stanol esters for 85 weeks does not affect neurocognitive functioning or mood in statin-treated hypercholesterolemic individuals.

    Science.gov (United States)

    Schiepers, Olga J G; de Groot, Renate H M; van Boxtel, Martin P J; Jolles, Jelle; de Jong, Ariënne; Lütjohann, Dieter; Plat, Jogchum; Mensink, Ronald P

    2009-07-01

    Recent animal and human studies have shown that plant sterols and stanols, which are used as functional food ingredients to lower increased LDL cholesterol concentrations, pass the blood-brain barrier. Whether this affects neurocognitive functioning and mental well-being in humans has, to our knowledge, never been investigated. The aim of the present study was therefore to examine the effects of long-term plant sterol or stanol consumption on neurocognitive functioning and mood in a randomized, double-blind, placebo-controlled dietary intervention trial. To this end, hypercholesterolemic individuals, aged 43-69 y, receiving stable statin treatment were randomly assigned to an 85-wk supplementation with margarines enriched with plant sterol esters (2.5 g/d), plant stanol esters (2.5 g/d), or placebo. At baseline and at the end of the intervention period, all participants underwent a cognitive assessment. In addition, subjective cognitive functioning and mood were assessed by means of questionnaires (Cognitive Failure Questionnaire and depression subscale of the Symptom Checklist 90, respectively). Long-term supplementation with plant sterol or stanol esters did not affect cognitive performance (memory, simple information processing speed, complex information processing speed, Letter-Digit Substitution test performance), subjective cognitive functioning, or mood. In conclusion, the present results indicate that long-term use of plant sterols or stanols at recommended intakes of 2.5 g/d does not affect neurocognitive functioning or mood in hypercholesterolemic individuals receiving statin treatment.

  9. Pulverization of boron element and proportions of boron carbide in boron

    International Nuclear Information System (INIS)

    Lang, F.M.; Finck, C.

    1956-01-01

    It is possible to reduce boron element into fine powder by means of a mortar and pestle made of sintered boron carbide, the ratio of boron carbide introduced being less than one per cent. Boron element at our disposal is made of sharp edged, dark brown, little grains of average size greater than 5 μ. Grain sizes smaller than 1μ are required for applying thin layers of such boron. (author) [fr

  10. Removal of boron species by layered double hydroxides: a review.

    Science.gov (United States)

    Theiss, Frederick L; Ayoko, Godwin A; Frost, Ray L

    2013-07-15

    Boron, which is an essential element for plants, is toxic to humans and animals at high concentrations. Layered double hydroxides (LDHs) and thermally activated LDHs have shown good uptake of a range of boron species in laboratory scale experiments when compared to current available methods, which are for the most part ineffective or prohibitively expensive. LDHs were able to remove anions from water by anion exchange, the reformation (or memory) effect and direct precipitation. The main mechanism of boron uptake appeared to be anion exchange, which was confirmed by powder X-ray diffraction (XRD) measurements. Solution pH appeared to have little effect on boron sorption while thermal activation did not always significantly improve boron uptake. In addition, perpetration of numerous LDHs with varying boron anions in the interlayer region by direct co-precipitation and anion exchange have been reported by a number of groups. The composition and orientation of the interlayer boron ions could be identified with reasonable certainty by applying a number of characterisation techniques including: powder XRD, nuclear magnetic resonance spectroscopy (NMR), X-ray photoelectron spectroscopy (XPS) and infrared (IR) spectroscopy. There is still considerable scope for future research on the application of LDHs for the removal of boron contaminants. Copyright © 2013 Elsevier Inc. All rights reserved.

  11. Effect of boron on growth criteria of some wheat cultivars

    Directory of Open Access Journals (Sweden)

    Ashraf Metwally

    2012-01-01

    Full Text Available Introduction: Toxic soil concentrations of the essential micronutrient boron (B represent major limitations to crop production worldwide. Plants have a range of defense systems that might be involved in their affinity to resist and tolerate nutrients stress.Materials and methods: The experiments were carried out to study the differential responses in five wheat cultivars to boron toxicity. Results: The fresh and dry matter yield of the test wheat cultivars showed marked decrease as the concentration of boron was increased. Elevated concentration of boron had a notable inhibitory effect on the biosynthesis of pigments fractions in the test wheat cultivars as severely as dry matter gain. The adverse concentration effects of boron on some metabolic responses were clearly displayed by shoot and root systems, exhibited in the elevated rates of proline, hydrogen peroxide and malondialdehyde formation. Potassium leakage was severely affected by boron-stress in some cultivars at all tested concentrations, while in some others a moderate damage was manifested only at the higher boron concentrations.Conclusions: Sakha 93 out of all the different cultivars investigated was found to display the lowest sensitivity to boron-stress, while Gemmeza 9 was the most sensitive one.

  12. Prospecting plant growth promoting bacteria and cyanobacteria as options for enrichment of macro- and micronutrients in grains in rice–wheat cropping sequence

    Directory of Open Access Journals (Sweden)

    Anuj Rana

    2015-12-01

    Full Text Available The influence of plant growth promoting bacteria (PGPB and cyanobacteria, alone and in combination, was investigated on micronutrient enrichment and yield in rice–wheat sequence, over a period of two years. Analysis of variance (ANOVA in both crops indicated significant differences in soil dehydrogenase activity and micronutrient enrichment in grains (Fe, Zn in rice, and Cu, Mn in wheat. The combined inoculation of Anabaena oscillarioides CR3, Brevundimonas diminuta PR7, and Ochrobactrum anthropi PR10 (T6 significantly increased nitrogen, phosphorus, and potassium (NPK content and improved rice yield by 21.2%, as compared to the application of recommended dose of NPK fertilizers (T2. The treatment T5 (Providencia sp. PR3 + B. diminuta PR7 + O. anthropi PR10 recorded an enhancement of 13–16% in Fe, Zn, Cu, and Mn concentrations, respectively, in rice grains. In wheat, Providencia sp. PW5 (T6 recorded the highest yield (5.23 Mg ha−1 and significantly higher enrichment of Fe and Cu (44–45% in the grains. This study highlighted the promise of combinations of cyanobacteria/bacteria and their synergistic action in biofortification and providing savings of 40–60 kg N ha−1. Future focus needs to be towards integrating such promising environment-friendly and environmentally sustainable options in nutrient management strategies for this cropping sequence.

  13. The enrichment of natural radionuclides in oil shale-fired power plants in Estonia – The impact of new circulating fluidized bed technology

    International Nuclear Information System (INIS)

    Vaasma, Taavi; Kiisk, Madis; Meriste, Tõnis; Tkaczyk, Alan Henry

    2014-01-01

    Burning oil shale to produce electricity has a dominant position in Estonia's energy sector. Around 90% of the overall electric energy production originates from the Narva Power Plants. The technology in use has been significantly renovated – two older types of pulverized fuel burning (PF) energy production units were replaced with new circulating fluidized bed (CFB) technology. Additional filter systems have been added to PF boilers to reduce emissions. Oil shale contains various amounts of natural radionuclides. These radionuclides concentrate and become enriched in different boiler ash fractions. More volatile isotopes will be partially emitted to the atmosphere via flue gases and fly ash. To our knowledge, there has been no previous study for CFB boiler systems on natural radionuclide enrichment and their atmospheric emissions. Ash samples were collected from Eesti Power Plant's CFB boiler. These samples were processed and analyzed with gamma spectrometry. Activity concentrations (Bq/kg) and enrichment factors were calculated for the 238 U ( 238 U, 226 Ra, 210 Pb) and 232 Th ( 232 Th, 228 Ra) family radionuclides and for 40 K in different CFB boiler ash fractions. Results from the CFB boiler ash sample analysis showed an increase in the activity concentrations and enrichment factors (up to 4.5) from the furnace toward the electrostatic precipitator block. The volatile radionuclide ( 210 Pb and 40 K) activity concentrations in CFB boilers were evenly distributed in finer ash fractions. Activity balance calculations showed discrepancies between input (via oil shale) and output (via ash fractions) activities for some radionuclides ( 238 U, 226 Ra, 210 Pb). This refers to a situation where the missing part of the activity (around 20% for these radionuclides) is emitted to the atmosphere. Also different behavior patterns were detected for the two Ra isotopes, 226 Ra and 228 Ra. A part of 226 Ra input activity, unlike 228 Ra, was undetectable in the solid

  14. Boron Removal in Seawater Reverse Osmosis System

    KAUST Repository

    Rahmawati, Karina

    2011-07-01

    Reverse osmosis successfully proves to remove more than 99% of solute in seawater, providing fresh water supply with satisfied quality. Due to some operational constraints, however, some trace contaminants removal, such as boron, cannot be achieved in one pass system. The stringent criterion for boron from World Health Organization (WHO) and Saudi Arabia local standard (0.5 mg/l) is hardly fulfilled by single pass sea water reverse osmosis (SWRO) plants. Some design processes have been proposed to deal with boron removal, but they are not economically efficient due to high energy and chemical consumption. The objective of this study was to study boron removal by different reverse osmosis membranes in two pH conditions, with and without antiscalant addition. Thus, it was expected to observe the possibility of operating single pass system and necessity to operate two pass system using low energy membrane. Five membrane samples were obtained from two different manufacturers. Three types of feed water pH were used, pH 8, pH 10, and pH 10 with antiscalant addition. Experiment was conducted in parallel to compare membrane performance from two manufacturers. Filtration was run with fully recycle mode for three days. Sample of permeate and feed were taken every 12 hours, and analyzed for their boron and TDS concentration. Membrane samples were also tested for their surface charge. The results showed that boron rejection increases as the feed pH increases. This was caused by dissociation of boric acid to negatively charged borate ion and more negatively charged membrane surface at elevated pH which enhance boron rejection. This study found that single pass reverse osmosis system, with and without elevating the pH, may not be possible to be applied because of two reasons. First, permeate quality in term of boron, does not fulfill WHO and local Saudi Arabia regulations. Second, severe scaling occurs due to operation in alkaline condition, since Ca and Mg concentration are

  15. Influence of fine process particles enriched with metals and metalloids on Lactuca sativa L. leaf fatty acid composition following air and/or soil-plant field exposure

    International Nuclear Information System (INIS)

    Schreck, Eva; Laplanche, Christophe; Le Guédard, Marina; Bessoule, Jean-Jacques; Austruy, Annabelle; Xiong, Tiantian; Foucault, Yann; Dumat, Camille

    2013-01-01

    We investigate the effect of both foliar and root uptake of a mixture of metal(loid)s on the fatty acid composition of plant leaves. Our objectives are to determine whether both contamination pathways have a similar effect and whether they interact. Lactuca sativa L. were exposed to fine process particles enriched with metal(loid)s in an industrial area. Data from a first experiment were used to conduct an exploratory statistical analysis which findings were successfully cross-validated by using the data from a second one. Both foliar and root pathways impact plant leaf fatty acid composition and do not interact. Z index (dimensionless quantity), weighted product of fatty acid concentration ratios was built up from the statistical analyses. It provides new insights on the mechanisms involved in metal uptake and phytotoxicity. Plant leaf fatty acid composition is a robust and fruitful approach to detect and understand the effects of metal(loid) contamination on plants. -- Highlights: •The study compares foliar and root transfers of metal(loid)s and their effects on plants. •Field experiments are performed combining ecotoxicological and statistical analyses. •The use of leaf fatty acid composition is a relevant indicator of exposure pathway. •The uptake pathways are independent, with an additive effect in terms of phytotoxicity. -- Metal uptake via both foliar and root pathways alters in a distinctive manner the fatty acid composition of lettuce leaves

  16. Development of enrichment techniques

    International Nuclear Information System (INIS)

    Mohrhauer, H.; Krey, M.

    1993-01-01

    The experience accumulated in operating the older uranium enrichment plants in Almelo and Capenhurst was the basis for the construction of the Gronau centrifuge plant commissioned in August 1985 after three and a half years of construction. The total capacity of the three Urenco plants as of late 1992 is 2750 t SWU/a. The goal set at the beginning of centrifuge development, i.e. to achive troublefree operation of the centrifuges for more than ten years, has been attained. Enrichment by centrifuges on the whole consumes less than one permil of the electric power generated. Economic calculations show that a laser plant is hardly able to underrun the costs of separative work of a centrifuge plant. (orig.) [de

  17. Plant-RRBS, a bisulfite and next-generation sequencing-based methylome profiling method enriching for coverage of cytosine positions.

    Science.gov (United States)

    Schmidt, Martin; Van Bel, Michiel; Woloszynska, Magdalena; Slabbinck, Bram; Martens, Cindy; De Block, Marc; Coppens, Frederik; Van Lijsebettens, Mieke

    2017-07-06

    Cytosine methylation in plant genomes is important for the regulation of gene transcription and transposon activity. Genome-wide methylomes are studied upon mutation of the DNA methyltransferases, adaptation to environmental stresses or during development. However, from basic biology to breeding programs, there is a need to monitor multiple samples to determine transgenerational methylation inheritance or differential cytosine methylation. Methylome data obtained by sodium hydrogen sulfite (bisulfite)-conversion and next-generation sequencing (NGS) provide genome-wide information on cytosine methylation. However, a profiling method that detects cytosine methylation state dispersed over the genome would allow high-throughput analysis of multiple plant samples with distinct epigenetic signatures. We use specific restriction endonucleases to enrich for cytosine coverage in a bisulfite and NGS-based profiling method, which was compared to whole-genome bisulfite sequencing of the same plant material. We established an effective methylome profiling method in plants, termed plant-reduced representation bisulfite sequencing (plant-RRBS), using optimized double restriction endonuclease digestion, fragment end repair, adapter ligation, followed by bisulfite conversion, PCR amplification and NGS. We report a performant laboratory protocol and a straightforward bioinformatics data analysis pipeline for plant-RRBS, applicable for any reference-sequenced plant species. As a proof of concept, methylome profiling was performed using an Oryza sativa ssp. indica pure breeding line and a derived epigenetically altered line (epiline). Plant-RRBS detects methylation levels at tens of millions of cytosine positions deduced from bisulfite conversion in multiple samples. To evaluate the method, the coverage of cytosine positions, the intra-line similarity and the differential cytosine methylation levels between the pure breeding line and the epiline were determined. Plant

  18. The Genome of the Generalist Plant Pathogen Fusarium avenaceum Is Enriched with Genes Involved in Redox, Signaling and Secondary Metabolism

    DEFF Research Database (Denmark)

    Lysøe, Erik; Harris, Linda J.; Walkowiak, Sean

    2014-01-01

    Fusarium avenaceum is a fungus commonly isolated from soil and associated with a wide range of host plants. We present here three genome sequences of F. avenaceum, one isolated from barley in Finland and two from spring and winter wheat in Canada. The sizes of the three genomes range from 41...... during interaction with plant hosts....

  19. Efeitos da aplicação de bórax em cultura de batatinha, em várzea irrigada, no Vale do Paraíba Effects of addition of boron on potato plant production

    Directory of Open Access Journals (Sweden)

    Norberto Leite

    1970-01-01

    Full Text Available São relatados os efeitos produzidos pela aplicação de bórax na cultura da batatinha (Solatium tuberosum L., em solos de várzea irrigada do Vale do Paraíba. Quatro doses de bórax - 10, 20, 30 e 40 kg/ha - foram aplicadas de três maneiras distintas: no sulco de plantio, em cobertura (vinte dias após a germinação e parceladamente em 4 pulverizações foliares semanais. As melhores doses de bórax foram as de 10 e 20 kg/ha, aplicadas no sulco de plantio, em mistura com os demais adubos. As aplicações em pulverização provocaram sintomas de toxidez nas folhas, notadamente as de maiores doses.The production of potato plants (Solatium tuberosum L. grown in alluvial soils of the Rio Paraíba Valey in the State of São Paulo, is not always correlated with high N-P-K fertilization. This has been reported to be due to boron deficiency in these soils. The effect of addition of boron at different rates (10, 20, 30 and 40 kg of borax / ha applied in mixture with common NPK formulation in the furrow at planting time, as side dressing or by spraying, was studied in an area where symptoms of deficiency was observed in Aquila potato variety, in the previous year. An increase in the production of about 20 % was obtained with the addition of 10 or 20 kg of borax / ha in mixtures with NPK fertilizing formulation but not with the two higher doses. The same amount of borax applied by spraying also increased yield but at a lesser extent and the side dressing technique was less effective than the other two methods of application of borax.

  20. Boron and strontium isotopic characterization of coal combustion residuals: validation of new environmental tracers.

    Science.gov (United States)

    Ruhl, Laura S; Dwyer, Gary S; Hsu-Kim, Heileen; Hower, James C; Vengosh, Avner

    2014-12-16

    In the U.S., coal fired power plants produce over 136 million tons of coal combustion residuals (CCRs) annually. CCRs are enriched in toxic elements, and their leachates can have significant impacts on water quality. Here we report the boron and strontium isotopic ratios of leaching experiments on CCRs from a variety of coal sources (Appalachian, Illinois, and Powder River Basins). CCR leachates had a mostly negative δ(11)B, ranging from -17.6 to +6.3‰, and (87)Sr/(86)Sr ranging from 0.70975 to 0.71251. Additionally, we utilized these isotopic ratios for tracing CCR contaminants in different environments: (1) the 2008 Tennessee Valley Authority (TVA) coal ash spill affected waters; (2) CCR effluents from power plants in Tennessee and North Carolina; (3) lakes and rivers affected by CCR effluents in North Carolina; and (4) porewater extracted from sediments in lakes affected by CCRs. The boron isotopes measured in these environments had a distinctive negative δ(11)B signature relative to background waters. In contrast (87)Sr/(86)Sr ratios in CCRs were not always exclusively different from background, limiting their use as a CCR tracer. This investigation demonstrates the validity of the combined geochemical and isotopic approach as a unique and practical identification method for delineating and evaluating the environmental impact of CCRs.

  1. Mathematical modeling based evaluation and simulation of boron removal in bioelectrochemical systems

    Energy Technology Data Exchange (ETDEWEB)

    Ping, Qingyun [Department of Civil and Environmental Engineering, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061 (United States); Abu-Reesh, Ibrahim M. [Department of Chemical Engineering, College of Engineering, Qatar University, P.O. Box 2713, Doha (Qatar); He, Zhen, E-mail: zhenhe@vt.edu [Department of Civil and Environmental Engineering, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061 (United States)

    2016-11-01

    Boron removal is an arising issue in desalination plants due to boron's toxicity. As an emerging treatment concept, bioelectrochemical systems (BES) can achieve potentially cost-effective boron removal by taking advantage of cathodic-produced alkali. Prior studies have demonstrated successful removal of boron in microbial desalination cells (MDCs) and microbial fuel cells (MFCs), both of which are representative BES. Herein, mathematical models were developed to further evaluate boron removal by different BES and understand the key operating factors. The models delivered very good prediction of the boron concentration in the MDC integrated with Donnan Dialysis (DD) system with the lowest relative root-mean-square error (RMSE) of 0.00%; the predication of the MFC performance generated the highest RMSE of 18.55%. The model results of salt concentration, solution pH, and current generation were well fitted with experimental data for RMSE values mostly below 10%. The long term simulation of the MDC-DD system suggests that the accumulation of salt in the catholyte/stripping solution could have a positive impact on the removal of boron due to osmosis-driven convection. The current generation in the MDC may have little influence on the boron removal, while in the MFC the current-driven electromigration can contribute up to 40% of boron removal. Osmosis-induced convection transport of boron could be the major driving force for boron removal to a low level < 2 mg L{sup −} {sup 1}. The ratio between the anolyte and the catholyte flow rates should be kept > 22.2 in order to avoid boron accumulation in the anolyte effluent. - Highlights: • Mathematical models are developed to understand boron removal in BES. • Boron removal can be driven by electromigration induced by current generation. • Diffusion induced by a salt concentration gradient also contributes to boron removal. • Osmosis and current driven convection transport play diverse roles in different BES.

  2. Uranium enrichment

    International Nuclear Information System (INIS)

    1989-01-01

    GAO was asked to address several questions concerning a number of proposed uranium enrichment bills introduced during the 100th Congress. The bill would have restructured the Department of Energy's uranium enrichment program as a government corporation to allow it to compete more effectively in the domestic and international markets. Some of GAO's findings discussed are: uranium market experts believe and existing market models show that the proposed DOE purchase of a $750 million of uranium from domestic producers may not significantly increase production because of large producer-held inventories; excess uranium enrichment production capacity exists throughout the world; therefore, foreign producers are expected to compete heavily in the United States throughout the 1990s as utilities' contracts with DOE expire; and according to a 1988 agreement between DOE's Offices of Nuclear Energy and Defense Programs, enrichment decommissioning costs, estimated to total $3.6 billion for planning purposes, will be shared by the commercial enrichment program and the government

  3. Plant architecture, auxin homeostasis and phenol content in Arabidopsis thaliana grown in cadmium- and zinc-enriched media.

    Science.gov (United States)

    Sofo, Adriano; Bochicchio, Rocco; Amato, Mariana; Rendina, Nunzia; Vitti, Antonella; Nuzzaci, Maria; Altamura, Maria Maddalena; Falasca, Giuseppina; Rovere, Federica Della; Scopa, Antonio

    2017-09-01

    A screening strategy using micropropagation glass tubes with a gradient of distances between germinating seeds and a metal-contaminated medium was used for studying alterations in root architecture and morphology of Arabidopsis thaliana treated with cadmium (Cd) and zinc (Zn) at the concentration of 10-20μM and 100-200μM, respectively. Metal concentrations in plant shoots and roots were measured by quadrupole inductively coupled plasma mass spectrometry. After 21days from germination, all plants in the tubes were scanned at high resolution and the root systems analyzed. The localization of indole-3-acetic acid (IAA) in the primary root and lateral root apices was monitored using DR5:GUS, LAX3:GUS and AUX1:GUS Arabidopsis transgenic lines. Total phenol content in leaves was measured spectrophotometrically. Shoot and root dry weight and leaf area did not change in Zn-exposed plants and significantly decreased in Cd-exposed plants, compared to control plants. Cadmium induced a reduction of root length, of mean number of roots and of total root surface. Both Cd- and Zn-exposed plants showed a reduced specific root length. This morphological behavior, together with an observed increase in root diameter in metal-exposed plants could be interpreted as compensatory growth, and the observed thicker roots could act as a barrier to protect root from the metals. In comparison with the apical localization of the IAA signal in the control plants, Zn generally reinforced the intensity of IAA signal, without affecting its localization. In Cd-exposed plants, IAA localization remained apical but weaker compared to control plants. Total phenols decreased in plants exposed to Zn and Cd. Therefore, we propose that the remodelling of the root architecture and the production of some secondary metabolites, such as IAA and phenols could be two responses of plants subjected to metal stress. This knowledge can open the way to future phytoremediation strategies of contaminated sites

  4. Effect of boron on growth criteria of some wheat cultivars

    OpenAIRE

    Ashraf Metwally; Rasha El-Shazoly; Afaf Mohamed Hamada

    2012-01-01

    Introduction: Toxic soil concentrations of the essential micronutrient boron (B) represent major limitations to crop production worldwide. Plants have a range of defense systems that might be involved in their affinity to resist and tolerate nutrients stress.Materials and methods: The experiments were carried out to study the differential responses in five wheat cultivars to boron toxicity. Results: The fresh and dry matter yield of the test wheat cultivars showed marked decrease as the conc...

  5. The Boron Isotopic Composition of Elephant Dung: Inputs to the Global Boron Budget

    Science.gov (United States)

    Williams, L. B.; Hervig, R. L.

    2011-12-01

    A survey of boron in kerogen showed isotopically light δ11B values (0 to -50%) that are distinctly different from most mineral and natural water B reservoirs. Diagenesis releases this isotopically light B into pore fluids when hydrocarbons are generated, thus enriching oilfield brines in 10B. This observation suggests that borated biomolecules (BM) are primarily tetrahedral favoring 10B, whereas 11B is preferred in trigonal coordination. Plants, with optimal concentrations up to 100ppm, contribute more B than animal remains to sediment. Elephants are one of the largest herbivores on earth, consuming 200 - 250 kg of plant material/day and producing 50 kg of manure/day. They are inefficient at digestion, thus the manure contains >50% undigested plant material. Dung samples are therefore ideal for studying the δ11B of both the food input and digested output of a significant B supply to sedimentary systems. Horse and rabbit manure were studied for comparison to evaluate B isotope variations in the food supply and potential vital effects on the output. B-content and isotopic composition of dung plant material and digested fractions were measured in the solid state by secondary ion mass spectrometry. The digests were rinsed in 1.8% mannitol, a B-complexing agent, to remove surface adsorbed-B, then air dried and Au-coated for charge compensation. Results showed that the elephant diet contains 3-13 ppm B, with an average δ11B of -20 ± 0.8% (1σ), while rabbit food had 88 ppm B with a δ11B of -50 ± 1.3 %. The digested fraction of the elephant dung contains 4-10ppm B with average δ11B values of -12 ± 1.2%. In comparison, horse manure with 11-21 ppm B has a δ11B of -10.7 ± 0.5% and rabbit manure contains 2-3 ppm B with a δ11B of -8.8 ± 1%. Boron isotope compositions of these manures are indistinguishable (within error). Clearly plant material is a major contributor of isotopically light B to sediments. The herbivores studied fractionate their total B intake in

  6. The role of above-ground competition and nitrogen vs. phosphorus enrichment in seedling survival of common European plant species of semi-natural grasslands.

    Directory of Open Access Journals (Sweden)

    Tobias Ceulemans

    Full Text Available Anthropogenic activities have severely altered fluxes of nitrogen and phosphorus in ecosystems worldwide. In grasslands, subsequent negative effects are commonly attributed to competitive exclusion of plant species following increased above-ground biomass production. However, some studies have shown that this does not fully account for nutrient enrichment effects, questioning whether lowering competition by reducing grassland productivity through mowing or herbivory can mitigate the environmental impact of nutrient pollution. Furthermore, few studies so far discriminate between nitrogen and phosphorus pollution. We performed a full factorial experiment in greenhouse mesocosms combining nitrogen and phosphorus addition with two clipping regimes designed to relax above-ground competition. Next, we studied the survival and growth of seedlings of eight common European grassland species and found that five out of eight species showed higher survival under the clipping regime with the lowest above-ground competition. Phosphorus addition negatively affected seven plant species and nitrogen addition negatively affected four plant species. Importantly, the negative effects of nutrient addition and higher above-ground competition were independent of each other for all but one species. Our results suggest that at any given level of soil nutrients, relaxation of above-ground competition allows for higher seedling survival in grasslands. At the same time, even at low levels of above-ground competition, nutrient enrichment negatively affects survival as compared to nutrient-poor conditions. Therefore, although maintaining low above-ground competition appears essential for species' recruitment, for instance through mowing or herbivory, these management efforts are likely to be insufficient and we conclude that environmental policies aimed to reduce both excess nitrogen and particularly phosphorus inputs are also necessary.

  7. Plant sterol-enriched soy milk consumption modulates 5-lipoxygenase, 12-lipoxygenase, and myeloperoxidase activities in healthy adults - a randomized-controlled trial.

    Science.gov (United States)

    Ho, Xing Lin; Liu, Jonathan Jia He; Loke, Wai Mun

    2016-12-01

    A randomized, double blind, placebo-controlled and crossover study was conducted to simultaneously measure the effects, after 3-h and 4-week daily exposure to plant sterols-enriched food product, on inflammation, oxidative status, 5-lipoxygenase, 12-lipoxygenase, and myeloperoxidase activities in healthy adults. Eighteen healthy participants (67% female, 35.3 (mean) ± 9.5 (SD) years, mean body mass index 22.8 kg m -2 ) received two soy milk (20g) treatments daily: placebo and one containing 2.0 g free plant sterols equivalent of their palmitates (β-sitosterol, 55%; campesterol, 29%; stigmasterol, 23%). F 2 -isoprostanes, leukotriene B 4 , sitosterol, campesterol, and stigmasterol concentrations were measured in the blood plasma and urine, using stable isotope-labeled gas chromatography-mass spectrometry. High-sensitivity c-reactive protein, tumor necrosis factor- α , and lipoxin A 4 concentrations in blood serum were measured using commercially available enzyme immunoassays. Myeloperoxidase activity, serum lipid hydroperoxides, plasma and urinary F 2 -isoprostanes, plasma and urinary leukotriene B 4 , and plasma high-sensitivity c-reactive protein concentrations were significantly reduced, while circulating lipoxin A 4 concentrations were significantly elevated after 4-week plant sterols treatment. Plant sterols treatment decreased plasma leukotriene B 4 and increased plasma lipoxin A 4 concentrations acutely. Total plant sterols, β-sitosterol, campesterol, and stigmasterol concentrations were significantly elevated after 4-week treatments compared with the pre-treatment concentrations. Our results suggest that dietary plant sterols, in the combination used, can alleviate lipid peroxidation and inflammatory events in vivo. These effects are possibly exerted via the modulation of myeloperoxidase, 5-lipoxygenase, and 12-lipoxygenase activities.

  8. Boronated liposome development and evaluation

    International Nuclear Information System (INIS)

    Hawthorne, M.F.

    1995-01-01

    The boronated liposome development and evaluation effort consists of two separate tasks. The first is the development of new boron compounds and the synthesis of known boron species with BNCT potential. These compounds are then encapsulated within liposomes for the second task, biodistribution testing in tumor-bearing mice, which examines the potential for the liposomes and their contents to concentrate boron in cancerous tissues

  9. Cutback sensitivity test for boron-free small modular PWR

    Science.gov (United States)

    Choe, J.; Shin, H. C.; Jeong, J. E.; Lee, D.

    2016-08-01

    A soluble boron-free small modular pressurized water reactor (SMPWR) uses burnable absorbers (BA) instead of soluble boron to reduce excess reactivity. As a consequence, the fuel cycle length can be shortened by the residual penalty of BA. This paper performs cutback sensitivity tests to extend the cycle length. The influence of the height of the cutback, of the 235U enrichment rate, and of the BA material on the power peaking factor (Fq), the axial offset (AO) and the fuel cycle length is analyzed with the reactor core design system, CASMO-4E/SIMULATE-3 code system.

  10. Automated instruments for in-line accounting of highly enriched uranium at the Oak Ridge Y-12 Plant

    International Nuclear Information System (INIS)

    Russo, P.A.; Strittmatter, R.B.; Sandford, E.L.; Stephens, M.M.; Brumfield, T.L.; Smith, S.E.; McCullough, E.E.; Jeter, I.W.; Bowers, G.L.

    1985-02-01

    Two automated nondestructive assay instruments developed at Los Alamos in support of nuclear materials accounting needs are currently operating in-line at the Oak Ridge Y-12 facility for recovery of highly enriched uranium (HEU). One instrument provides the HEU inventory in the secondary solvent extraction system, and the other monitors HEU concentration in the secondary intermediate evaporator. Both instruments were installed in December 1982. Operational evaluation of these instruments was a joint effort of Y-12 and Los Alamos personnel. This evaluation included comparison of the solvent extraction system inventories with direct measurements performed on the dumped solution components of the solvent extraction system and comparison of concentration assay results with the external assays of samples withdrawn from the process. The function and design of the instruments and detailed results of the operational evaluation are reported

  11. Does leaf photosynthesis adapt to CO2-enriched environments? An experiment on plants originating from three natural CO2 springs.

    Science.gov (United States)

    Onoda, Yusuke; Hirose, Tadaki; Hikosaka, Kouki

    2009-01-01

    Atmospheric CO2 elevation may act as a selective agent, which consequently may alter plant traits in the future. We investigated the adaptation to high CO2 using transplant experiments with plants originating from natural CO2 springs and from respective control sites. We tested three hypotheses for adaptation to high-CO2 conditions: a higher photosynthetic nitrogen use efficiency (PNUE); a higher photosynthetic water use efficiency (WUE); and a higher capacity for carbohydrate transport from leaves. Although elevated growth CO2 enhanced both PNUE and WUE, there was no genotypic improvement in PNUE. However, some spring plants had a higher WUE, as a result of a significant reduction in stomatal conductance, and also a lower starch concentration. Higher natural variation (assessed by the coefficient of variation) within populations in WUE and starch concentration, compared with PNUE, might be responsible for the observed population differentiation. These results support the concept that atmospheric CO2 elevation can act as a selective agent on some plant traits in natural plant communities. Reduced stomatal conductance and reduced starch accumulation are highlighted for possible adaptation to high CO2.

  12. Structural characterization of electrodeposited boron

    Indian Academy of Sciences (India)

    mental phase contrast images and the diffraction pattern. Figure 3. (a) Bright field image of electrodeposited boron spec- imen showing a crystallite of size ∼10 × 5 nm; (b) phase contrast image of electrodeposited boron specimen showing a resolved la- ttice and (c) power spectrum of electrodeposited boron specimen.

  13. Enhanced boron removal by electricity generation in a microbial fuel cell

    OpenAIRE

    Ping, Qingyun; Abu-Reesh, Ibrahim M.; He, Zhen

    2016-01-01

    Boron needs to be removed during desalination, because excessive boron in the product water for irrigation can deteriorate plant growth. In this study, a microbial fuel cell (MFC) equipped with anion exchange membrane (AEM) was proposed and investigated to remove boron via two successive steps: boric acid is ionized to borate ions in the presence of high pH as a result of cathode reaction, and borate ions are transported across AEM driven by electricity generation. Two scenarios were examined...

  14. Influence of boron on the morphological and physiological growth parameters of bean

    International Nuclear Information System (INIS)

    Oliveira, S.A. de

    1982-01-01

    Effect of boron on Phaseolus vulgaris L. var. Cacahuate was studied in nutrient solutions containing 0.000; 0.005; 0.050 and 0.500 ppm of the element. The deficiency of boron affected root growth, leaf development and plant growth. Lower values of net assimilation rate (NAR) indicated reduced photosynthetic activity in the case of boron deficiency. (M.A.C.) [pt

  15. Standard specification for boron-Based neutron absorbing material systems for use in nuclear spent fuel storage racks

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2011-01-01

    1.1 This specification defines criteria for boron-based neutron absorbing material systems used in racks in a pool environment for storage of nuclear light water reactor (LWR) spent-fuel assemblies or disassembled components to maintain sub-criticality in the storage rack system. 1.2 Boron-based neutron absorbing material systems normally consist of metallic boron or a chemical compound containing boron (for example, boron carbide, B4C) supported by a matrix of aluminum, steel, or other materials. 1.3 In a boron-based absorber, neutron absorption occurs primarily by the boron-10 isotope that is present in natural boron to the extent of 18.3 ± 0.2 % by weight (depending upon the geological origin of the boron). Boron, enriched in boron-10 could also be used. 1.4 The materials systems described herein shall be functional – that is always be capable to maintain a B10 areal density such that subcriticality Keff <0.95 or Keff <0.98 or Keff < 1.0 depending on the design specification for the service...

  16. Energy and mass dependence of isotopic enrichment in sputtering

    CERN Document Server

    Shutthanandan, V; Ray, P

    2003-01-01

    Silver, copper, and boron (from a boron nitride target) were sputtered with xenon ions. The isotopic composition of secondary ions of silver was measured at ion energies ranging from 300 eV to 3 keV and, for copper and boron, at 2.0, 2.5, and 3.0 keV. An ion gun was used to generate the ion beam. The secondary ions were detected at a small emission angle by a quadrupole mass spectrometer. The secondary-ion flux of silver was found to be enriched in heavy isotopes at lower incident-ion energies. The heavy-isotope enrichment was observed to decrease with increasing primary-ion energy. Beyond 500 eV, light isotopes of silver were sputtered preferentially with the enrichment increasing to a constant value of 1.018. The sputtered flux of copper and boron also indicated constant enrichments (1.008 and 1.281 for copper and boron respectively) in light isotopes at high ion energies. (orig.)

  17. Uranium enrichment. 1980 annual report

    International Nuclear Information System (INIS)

    1981-05-01

    This report contains data and related information on the production of enriched uranium at the gaseous diffusion plants and an update on the construction and project control center for the gas centrifuge plant. Power usage at the gaseous diffusion plants is illustrated. The report contains several glossy color pictures of the plants and processes described. In addition to gaseous diffusion and the centrifuge process, three advanced isotope separation process are now being developed. The business operation of the enrichment plants is described; charts on revenue, balance sheets, and income statements are included

  18. Enrichment and distribution of 24 elements within the sub-sieve particle size distribution ranges of fly ash from wastes incinerator plants.

    Science.gov (United States)

    Raclavská, Helena; Corsaro, Agnieszka; Hartmann-Koval, Silvie; Juchelková, Dagmar

    2017-12-01

    The management of an increasing amount of municipal waste via incineration has been gaining traction. Fly ash as a by-product of incineration of municipal solid waste is considered a hazardous waste due to the elevated content of various elements. The enrichment and distribution of 24 elements in fly ash from three wastes incinerators were evaluated. Two coarse (>100 μm and sieve (12-16, 16-23, 23-34, 34-49, and 49-100 μm) particle size fractions separated on a cyclosizer system were analyzed. An enhancement in the enrichment factor was observed in all samples for the majority of elements in >100 μm range compared with sieve particle size ranges. These variations were attributed primarily to: (i) the vaporization and condensation mechanisms, (ii) the different design of incineration plants, (iii) incineration properties, (iv) the type of material being incinerated, and (v) the affinity of elements. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Feasibility studies to establish at the Kazakhstan Ulba metallurgical plant the manufacturing capability to produce low-enriched uranium certified reference materials

    Energy Technology Data Exchange (ETDEWEB)

    Kuzminski, Jozef [Los Alamos National Laboratory; Nesuhoff, J [NBL; Cratto, P [NBL; Pfennigwerth, G [Y12 NATIONAL SEC. COMPLEX; Mikhailenko, A [ULBA METALLURGICAL PLANT; Maliutina, I [ULBA METALLURGICAL PLANT; Nations, J [GREGG PROTECTION SERVICES

    2009-01-01

    One of the salient features of the transition plan that the United States Department of Energy/National Nuclear Security Administration (DOE/NNSA) is presently implementing in the Former Soviet Union countries is the availability of uranium certified reference materials for calibration of nondestructive assay (NDA) measurement equipment. To address this challenge, DOE/NNSA and U.S. national laboratories have focused their cooperative efforts on establishing a reliable source for manufacturing, certifying, and supplying of such standards. The Ulba Metallurgical Plant (UMP), Kazakhstan, which processes large quantities of low-enriched uranium to produce ceramic fuel pellets for nuclear-powered reactors, is well situated to become a key supplier of low-enriched uranium certified reference materials for the country and Central Asia region. We have recently completed Phase I of a feasibility study to establish at UMP capabilities of manufacturing these standards. In this paper we will discuss details of a proposed methodology for uranium down-blending, material selection and characterization, and a proposed methodology of measurement by destructive (DA) and non-destructive (NDA) analysis to form a database for material certification by the competent State authorities in the Republic of Kazakhstan. In addition, we will discuss the prospect for manufacturing of such standards at UMP.

  20. Enrichment and Broad Representation of Plant Biomass-Degrading Enzymes in the Specialized Hyphal Swellings of Leucoagaricus gongylophorus, the Fungal Symbiont of Leaf-Cutter Ants

    Energy Technology Data Exchange (ETDEWEB)

    Aylward, Frank O.; Khadempour, Lily; Tremmel, Daniel; McDonald, Bradon R.; Nicora, Carrie D.; Wu, Si; Moore, Ronald J.; Orton, Daniel J.; Monroe, Matthew E.; Piehowski, Paul D.; Purvine, Samuel O.; Smith, Richard D.; Lipton, Mary S.; Burnum-Johnson, Kristin E.; Currie, Cameron R.

    2015-08-28

    Leaf-cutter ants are prolific and conspicuous Neotropical herbivores that derive energy from specialized fungus gardens they cultivate using foliar biomass. The basidiomycetous cultivar of the ants, Leucoagaricus gongylophorus, produces specialized hyphal swellings called gongylidia that serve as the primary food source of ant colonies. Gongylidia also contain lignocellulases that become concentrated in ant digestive tracts and are deposited within fecal droplets onto fresh foliar material as it is foraged by the ants. Although the enzymes concentrated by L. gongylophorus within gongylidia are thought to be critical to the initial degradation of plant biomass, only a few enzymes present in these hyphal swellings have been identified. Here we use proteomic methods to identify proteins present in the gongylidia of three Atta cephalotes colonies. Our results demonstrate that a diverse but consistent set of enzymes is present in gongylidia, including numerous lignocellulases likely involved in the degradation of polysaccharides, plant toxins, and proteins. Overall, gongylidia contained over three-quarters of all lignocellulases identified in the L. gongylophorus genome, demonstrating that the majority of the enzymes produced by this fungus for biomass breakdown are ingested by the ants. We also identify a set of 23 lignocellulases enriched in gongylidia compared to whole fungus garden samples, suggesting that certain enzymes may be particularly important in the initial degradation of foliar material. Our work sheds light on the complex interplay between leaf-cutter ants and their fungal symbiont that allows for the host insects to occupy an herbivorous niche by indirectly deriving energy from plant biomass.

  1. Field test of short-notice random inspections for inventory-change verification at a low-enriched-uranium fuel-fabrication plant

    International Nuclear Information System (INIS)

    Fishbone, L.G.; Moussalli, G.; Naegele, G.

    1995-01-01

    An approach of short-notice random inspections (SNRIs) for inventory-change verification can enhance the effectiveness and efficiency of international safeguards at natural or low-enriched uranium (LEU) fuel fabrication plants. According to this approach, the plant operator declares the contents of nuclear material items before knowing if an inspection will occur to verify them. Additionally, items about which declarations are newly made should remain available for verification for an agreed time. Then a statistical inference can be made from verification results for items verified during SNRIs to the entire populations, i.e. the entire strata, even if inspectors were not present when many items were received or produced. A six-month field test of the feasibility of such SNRIs took place at the Westinghouse Electric Corporation Commercial Nuclear Fuel Division during 1993. Westinghouse personnel made daily declarations about both feed and product items, uranium hexafluoride cylinders and finished fuel assemblies, using a custom-designed computer ''mailbox''. Safeguards inspectors from the IAEA conducted eight SNRIs to verify these declarations. They arrived unannounced at the plant, in most cases immediately after travel from Canada, where the IAEA maintains a regional office. Items from both strata were verified during the SNRIs by meant of nondestructive assay equipment

  2. Plant phenology, growth and nutritive quality of Briza maxima: Responses induced by enhanced ozone atmospheric levels and nitrogen enrichment

    International Nuclear Information System (INIS)

    Sanz, J.; Bermejo, V.; Muntifering, R.; Gonzalez-Fernandez, I.; Gimeno, B.S.; Elvira, S.; Alonso, R.

    2011-01-01

    An assessment of the effects of tropospheric ozone (O 3 ) levels and substrate nitrogen (N) supplementation, singly and in combination, on phenology, growth and nutritive quality of Briza maxima was carried out. Two serial experiments were developed in Open-Top Chambers (OTC) using three O 3 and three N levels. Increased O 3 exposure did not affect the biomass-related parameters, but enhanced senescence, increased fiber foliar content (especially lignin concentration) and reduced plant life span; these effects were related to senescence acceleration induced by the pollutant. Added N increased plant biomass production and improved nutritive quality by decreasing foliar fiber concentration. Interestingly, the effects of N supplementation depended on meteorological conditions and plant physiological activity. N supplementation counteracted the O 3 -induced senescence but did not modifiy the effects on nutritive quality. Nutritive quality and phenology should be considered in new definitions of the O 3 limits for the protection of herbaceous vegetation. - Research highlights: → Forage quality (foliar protein and fiber content) and phenology are more O 3 -sensitive than growth parameters in the Mediterranean annual grass Briza maxima. → The effects of N supplementation depended on meteorological conditions and plant physiological activity. → Increase in nitrogen supplementation counterbalanced the O 3 -induced increase in senescence biomass. → Nutritive quality and phenology should be considered in new definitions of the O 3 limits for the protection of natural herbaceous vegetation. - Forage quality and phenology are more O 3 -sensitive than growth parameters in the Mediterranean annual grass Briza maxima.

  3. 10 CFR Appendix C to Part 110 - Illustrative List of Gaseous Diffusion Enrichment Plant Assemblies and Components Under NRC...

    Science.gov (United States)

    2010-01-01

    ... of the gas flow is of importance in a gaseous diffusion plant. All this leads to a need to equip the... are normally designed for a buffer gas in-leakage rate of less than 1000 cm3/min. 1.5 Heat Exchangers...

  4. 10 CFR Appendix B to Part 110 - Illustrative List of Gas Centrifuge Enrichment Plant Components Under NRC's Export Licensing...

    Science.gov (United States)

    2010-01-01

    ... the centrifuges or to control the plant. Normally UF6 is evaporated from the solid using heated... disc-shaped baffle(s) and a stationary tube arrangement for feeding and extracting UF6 gas and... main separation chamber and, in some cases, to assist the UF6 gas circulation within the main...

  5. In Vivo Boron Uptake Determination for Boron Neutron Capture Synovectomy

    Energy Technology Data Exchange (ETDEWEB)

    Binello, Emanuela; Shortkroff, Sonya; Yanch, Jacquelyn C.

    1999-06-06

    Boron neutron capture synovectomy (BNCS) has been proposed as a new application of the boron neutron capture reaction for the treatment of rheumatoid arthritis. In BNCS, a boron compound is injected into the joint space, where it is taken up by the synovium. The joint is then irradiated with neutrons of a desired energy range, inducing the boron neutron capture reaction in boron-loaded cells. Boron uptake by the synovium is an important parameter in the assessment of the potential of BNCS and in the determination of whether to proceed to animal irradiations for the testing of therapeutic efficacy. We present results from an investigation of boron uptake in vivo by the synovium.

  6. Emerging Technologies for the Production of Renewable Liquid Transport Fuels from Biomass Sources Enriched in Plant Cell Walls.

    Science.gov (United States)

    Tan, Hwei-Ting; Corbin, Kendall R; Fincher, Geoffrey B

    2016-01-01

    Plant cell walls are composed predominantly of cellulose, a range of non-cellulosic polysaccharides and lignin. The walls account for a large proportion not only of crop residues such as wheat straw and sugarcane bagasse, but also of residues of the timber industry and specialist grasses and other plants being grown specifically for biofuel production. The polysaccharide components of plant cell walls have long been recognized as an extraordinarily large source of fermentable sugars that might be used for the production of bioethanol and other renewable liquid transport fuels. Estimates place annual plant cellulose production from captured light energy in the order of hundreds of billions of tons. Lignin is synthesized in the same order of magnitude and, as a very large polymer of phenylpropanoid residues, lignin is also an abundant, high energy macromolecule. However, one of the major functions of these cell wall constituents in plants is to provide the extreme tensile and compressive strengths that enable plants to resist the forces of gravity and a broad range of other mechanical forces. Over millions of years these wall constituents have evolved under natural selection to generate extremely tough and resilient biomaterials. The rapid degradation of these tough cell wall composites to fermentable sugars is therefore a difficult task and has significantly slowed the development of a viable lignocellulose-based biofuels industry. However, good progress has been made in overcoming this so-called recalcitrance of lignocellulosic feedstocks for the biofuels industry, through modifications to the lignocellulose itself, innovative pre-treatments of the biomass, improved enzymes and the development of superior yeasts and other microorganisms for the fermentation process. Nevertheless, it has been argued that bioethanol might not be the best or only biofuel that can be generated from lignocellulosic biomass sources and that hydrocarbons with intrinsically higher energy

  7. Emerging Technologies for the Production of Renewable Liquid Transport Fuels from Biomass Sources Enriched in Plant Cell Walls

    Directory of Open Access Journals (Sweden)

    Hwei-Ting Tan

    2016-12-01

    Full Text Available Plant cell walls are composed predominantly of cellulose, a range of non-cellulosic polysaccharides and lignin. The walls account for a large proportion not only of crop residues such as wheat straw and sugarcane bagasse, but also of residues of the timber industry and specialist grasses and other plants being grown specifically for biofuel production. The polysaccharide components of plant cell walls have long been recognized as an extraordinarily large source of fermentable sugars that might be used for the production of bioethanol and other renewable liquid transport fuels. Estimates place annual plant cellulose production from captured light energy in the order of hundreds of billions of tonnes. Lignin is synthesised in the same order of magnitude and, as a very large polymer of phenylpropanoid residues, lignin is also an abundant, high energy macromolecule. However, one of the major functions of these cell wall constituents in plants is to provide the extreme tensile and compressive strengths that enable plants to resist the forces of gravity and a broad range of other mechanical forces. Over millions of years these wall constituents have evolved under natural selection to generate extremely tough and resilient biomaterials. The rapid degradation of these tough cell wall composites to fermentable sugars is therefore a difficult task and has significantly slowed the development of a viable lignocellulose-based biofuels industry. However, good progress has been made in overcoming this so-called recalcitrance of lignocellulosic feedstocks for the biofuels industry, through modifications to the lignocellulose itself, innovative pre-treatments of the biomass, improved enzymes and the development of superior yeasts and other microorganisms for the fermentation process. Nevertheless, it has been argued that bioethanol might not be the best or only biofuel that can be generated from lignocellulosic biomass sources and that hydrocarbons with

  8. OsNIP3;1, a rice boric acid channel, regulates boron distribution and is essential for growth under boron-deficient conditions.

    Science.gov (United States)

    Hanaoka, Hideki; Uraguchi, Shimpei; Takano, Junpei; Tanaka, Mayuki; Fujiwara, Toru

    2014-06-01

    Boron is an essential micronutrient for higher plants. Boron deficiency is an important agricultural issue because it results in loss of yield quality and/or quantity in cereals and other crops. To understand boron transport mechanisms in cereals, we characterized OsNIP3;1, a member of the major intrinsic protein family in rice (Oryza sativa L.), because OsNIP3;1 is the most similar rice gene to the Arabidopsis thaliana boric acid channel genes AtNIP5;1 and AtNIP6;1. Yeast cells expressing OsNIP3;1 imported more boric acid than control cells. GFP-tagged OsNIP3;1 expressed in tobacco BY2 cells was localized to the plasma membrane. The accumulation of OsNIP3;1 transcript increased fivefold in roots within 6 h of the onset of boron starvation, but not in shoots. Promoter-GUS analysis suggested that OsNIP3;1 is expressed mainly in exodermal cells and steles in roots, as well as in cells around the vascular bundles in leaf sheaths and pericycle cells around the xylem in leaf blades. The growth of OsNIP3;1 RNAi plants was impaired under boron limitation. These results indicate that OsNIP3;1 functions as a boric acid channel, and is required for acclimation to boron limitation. Boron distribution among shoot tissues was altered in OsNIP3;1 knockdown plants, especially under boron-deficient conditions. This result demonstrates that OsNIP3;1 regulates boron distribution among shoot tissues, and that the correct boron distribution is crucial for plant growth. © 2014 The Authors The Plant Journal © 2014 John Wiley & Sons Ltd.

  9. Boron isotope separation by ion exchange chromatography using weakly basic anion exchange resin

    International Nuclear Information System (INIS)

    Sakuma, Yoichi; Aida, Masao; Okamoto, Makoto; Kakihana, Hidetake

    1980-01-01

    Isotopic plateau displacement chromatography, a useful method for isotope separation is presented. The boric acid band formed in a column of weakly basic anion exchange resin Diaion WA21 can be eluted with pure water. In order to obtain good accumulation of the isotope effect, a series of experiments with different migration length were carried out. The boron-10 enriched part of the boric acid absorbed band was always preceded by the isotopic plateau part, in which the atomic fraction of boron-10 was maintained at its original value. The atomic fraction of boron-10 at the end of the chromatogram increased with migration length, and in the case of 256-m migration, boron-10 was enriched from its original atomic fraction of 19.84 to 91.00%, the separation factor S being constant irrespective of migration length: S = 1.0100 +- 0.0005. (author)

  10. Plant phenology, growth and nutritive quality of Briza maxima: Responses induced by enhanced ozone atmospheric levels and nitrogen enrichment

    Energy Technology Data Exchange (ETDEWEB)

    Sanz, J., E-mail: j.sanz@ciemat.e [Ecotoxicity of Atmospheric Pollutants, CIEMAT, Avda, Complutense 22, 28040 Madrid (Spain); Bermejo, V., E-mail: victoria.bermejo@ciemat.e [Ecotoxicity of Atmospheric Pollutants, CIEMAT, Avda, Complutense 22, 28040 Madrid (Spain); Muntifering, R., E-mail: muntirb@auburn.ed [Department of Animal Sciences, Auburn University, Auburn, AL 36849 (United States); Gonzalez-Fernandez, I., E-mail: ignacio.gonzalez@ciemat.e [Ecotoxicity of Atmospheric Pollutants, CIEMAT, Avda, Complutense 22, 28040 Madrid (Spain); Gimeno, B.S., E-mail: benjamin.gimeno@ciemat.e [Ecotoxicity of Atmospheric Pollutants, CIEMAT, Avda, Complutense 22, 28040 Madrid (Spain); Elvira, S., E-mail: susana.elvira@ciemat.e [Ecotoxicity of Atmospheric Pollutants, CIEMAT, Avda, Complutense 22, 28040 Madrid (Spain); Alonso, R., E-mail: rocio.alonso@ciemat.e [Ecotoxicity of Atmospheric Pollutants, CIEMAT, Avda, Complutense 22, 28040 Madrid (Spain)

    2011-02-15

    An assessment of the effects of tropospheric ozone (O{sub 3}) levels and substrate nitrogen (N) supplementation, singly and in combination, on phenology, growth and nutritive quality of Briza maxima was carried out. Two serial experiments were developed in Open-Top Chambers (OTC) using three O{sub 3} and three N levels. Increased O{sub 3} exposure did not affect the biomass-related parameters, but enhanced senescence, increased fiber foliar content (especially lignin concentration) and reduced plant life span; these effects were related to senescence acceleration induced by the pollutant. Added N increased plant biomass production and improved nutritive quality by decreasing foliar fiber concentration. Interestingly, the effects of N supplementation depended on meteorological conditions and plant physiological activity. N supplementation counteracted the O{sub 3}-induced senescence but did not modifiy the effects on nutritive quality. Nutritive quality and phenology should be considered in new definitions of the O{sub 3} limits for the protection of herbaceous vegetation. - Research highlights: Forage quality (foliar protein and fiber content) and phenology are more O{sub 3}-sensitive than growth parameters in the Mediterranean annual grass Briza maxima. The effects of N supplementation depended on meteorological conditions and plant physiological activity. Increase in nitrogen supplementation counterbalanced the O{sub 3}-induced increase in senescence biomass. Nutritive quality and phenology should be considered in new definitions of the O{sub 3} limits for the protection of natural herbaceous vegetation. - Forage quality and phenology are more O{sub 3}-sensitive than growth parameters in the Mediterranean annual grass Briza maxima.

  11. Process for microwave sintering boron carbide

    Science.gov (United States)

    Holcombe, C.E.; Morrow, M.S.

    1993-10-12

    A method of microwave sintering boron carbide comprises leaching boron carbide powder with an aqueous solution of nitric acid to form a leached boron carbide powder. The leached boron carbide powder is coated with a glassy carbon precursor to form a coated boron carbide powder. The coated boron carbide powder is consolidated in an enclosure of boron nitride particles coated with a layer of glassy carbon within a container for microwave heating to form an enclosed coated boron carbide powder. The enclosed coated boron carbide powder is sintered within the container for microwave heating with microwave energy.

  12. Bright prospects for boron

    NARCIS (Netherlands)

    Nanver, L.; Wassink, J.

    2012-01-01

    Professor Lis Nanver at Dimes has laid the foundation for a range of new photodetectors by creating a thin coating of boron on a silicon substrate. The sensors are used in ASML’s latest lithography machines and FEI’s most sensitive electron microscopes.

  13. Colorimetric determination of Boron-10 in macromolecular delivery agents

    Energy Technology Data Exchange (ETDEWEB)

    Camillo, Maria A.P.; Moura, Eduardo [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil). Centro de Biologia Molecular]. E-mail: mcamillo@ipen.br; Queiroz, Alvaro A.A.A.de [Universidade Federal de Itajuba, MG (Brazil). Inst. de Ciencias Exatas. Dept. de Fisica e Quimica]. E-mail: alencar@unifei.edu.br

    2005-07-01

    A polyglycerol with dendritic structure (PGLD) was synthesized by the ring opening polymerization of deprotonated glycidol using a polyglycerol as core functionality in a step-growth process denominated divergent synthesis. After PGLD reaction with {sup 10}B-enriched boric acid there was a marked increase in the bulk viscosity of the PGLD dendrimer evidencing the polyester formation. Gel permeation chromatography (GPC) analysis was used to characterize the molecular weight and the polydispersivity of the synthesized PGLD dendrimer. A dendritic polyglycerol structure with M{sub n} value of 16.7 kDa and a narrow polydispersivity (M{sub w}/M{sub n} = 1.05) was obtained in this work. {sup 1}H-NMR and {sup 13}C-NMR measurements were employed to assess the degree of branching (DB) in PGLD. The DB of 0.85 indicates the tendency of a dentritic structure for the PGLD synthesized in this work. The boron-10 concentration was dependent of the PGLD generation. A selective reagent, curcumine, was studied for spectrophotometric determination of boron in polyglycerol dendrimers. Boron reacts with curcumine to form a complex, which has a maximum absorption peak at 552 nm. Under the optimal conditions, Beer's law was obeyed over the range 0{approx}20 {mu}g of boron in 25 mL of solution. The biological assays indicate the PGLD-B with boron-10 concentration of 25 mg{sup 10}B/gPGLD as the most promising macromolecule enriched with boron-10 for the BNCT therapy. (author)

  14. Isotope enrichment

    International Nuclear Information System (INIS)

    Garbuny, M.

    1979-01-01

    The invention discloses a method for deriving, from a starting material including an element having a plurality of isotopes, derived material enriched in one isotope of the element. The starting material is deposited on a substrate at less than a critical submonatomic surface density, typically less than 10 16 atoms per square centimeter. The deposit is then selectively irradiated by a laser (maser or electronic oscillator) beam with monochromatic coherent radiation resonant with the one isotope causing the material including the one istope to escape from the substrate. The escaping enriched material is then collected. Where the element has two isotopes, one of which is to be collected, the deposit may be irradiated with radiation resonant with the other isotope and the residual material enriched in the one isotope may be evaporated from the substrate and collected

  15. Effects of dietary boron in rats fed a vitamin D-deficient diet.

    OpenAIRE

    Dupre, J N; Keenan, M J; Hegsted, M; Brudevold, A M

    1994-01-01

    Although boron has long been known to be a required nutrient for plants, it was not until recently that there was any suggestion of a nutritional requirement for animals and humans. Addition of boron to the diet of vitamin D-deficient chicks indicated that boron may play a role in animal nutrition. Studies with rats have demonstrated that supplemental dietary boron has most marked effects when the diet is deficient in known nutrients. We observed higher apparent-balance values of calcium, mag...

  16. Boron exposure assessment using drinking water and urine in the North of Chile

    Energy Technology Data Exchange (ETDEWEB)

    Cortes, S., E-mail: scortes@med.puc.cl [Departamento de Salud Publica, Pontificia Universidad Catolica de Chile, Santiago (Chile); Reynaga-Delgado, E. [Centro de Investigaciones Biologicas del Noroeste, La Paz B.C.S. (Mexico); Sancha, A.M. [Facultad de Ciencias Fisicas y Matematicas, Universidad de Chile, Santiago (Chile); Ferreccio, C. [Departamento de Salud Publica, Pontificia Universidad Catolica de Chile, Santiago (Chile)

    2011-12-01

    Boron is an essential trace element for plants and humans however it is still an open question what levels of boron are actually safe for humans. This study, conducted between 2006 and 2010, measured exposure levels of boron in drinking water and urine of volunteers in Arica, an area in the North of Chile with high levels of naturally occurring boron. Samples were taken of tap and bottled water (173 and 22, respectively), as well as urine from 22 volunteers, and subsequently analyzed by inductively coupled plasma spectroscopy (ICP-OES). Boron varied in public tap water from 0.22 to 11.3 mg L{sup -1}, with a median value of 2.9 mg L{sup -1}, while concentrations of boron in bottled water varied from 0.01 to 12.2 mg L{sup -1}. Neither tap nor bottled water samples had concentrations of boron within WHO recommended limits. The concentration of boron in urine varied between 0.45 and 17.4 mg L{sup -1}, with a median of 4.28 mg L{sup -1} and was found to be correlated with tap water sampled from the homes of the volunteers (r = 0.64). Authors highly recommend that in northern Chile - where levels of boron are naturally high - that the tap and bottled water supplies be monitored in order to protect public health and that regulatory standards also be established for boron in drinking water in order to limit exposure.

  17. Efeito do boro na nodulação da ervilha cultivada em solos de várzea Boron effects on nodule development in pea plants cultivated in lowland soils

    Directory of Open Access Journals (Sweden)

    Watson Rogério de Azevedo

    2002-08-01

    Full Text Available O objetivo deste trabalho foi avaliar o efeito do boro na nodulação da ervilha (Pisum sativum L. cv. Torta de Flor Roxa, cultivada em solos de várzea em condições de casa de vegetação, entre maio e julho de 1998. Amostras de Neossolo Flúvico, Gleissolo Háplico, Gleissolo Melânico e Organossolo Mésico artificialmente drenado foram coletadas na camada de 0-20 cm. Essas amostras foram previamente cultivadas com rabanete, e receberam calcário, P, K, S, Cu e Zn e seis doses de B (0,0, 0,25, 0,5, 1,5, 3,0 e 6,0 mg dm-3. Por ocasião do cultivo da ervilha aplicou-se apenas K (100 mg dm-3. O delineamento experimental foi inteiramente casualizado, em esquema fatorial 4x6, com três repetições. Foram cultivadas três plantas por vaso, cujas sementes, na época da semeadura, foram submetidas à inoculação com estirpes de Rhizobium leguminosarum (BR 618 e BR 619. Para verificação da existência de estirpes nativas de rizóbio, cultivaram-se sem inoculação nas sementes, três vasos, de cada solo, que haviam recebido a mesma dose de calcário, a mesma adubação básica e 0,5 mg dm-3 de boro. Aos 45 dias após o plantio, em pleno florescimento, colheu-se o experimento. Não foram observadas estirpes nativas nos solos avaliados. Nos solos Gleissolo Háplico e Organossolo Mésico artificialmente drenado, as doses de B influenciaram a nodulação e a atividade da nitrogenase.The objective of this work was to evaluate the effect of boron on nodule development in pea Pisum sativum L. plants cultivated in lowland soils under greenhouse conditions from May to July, 1998. Samples of Alluvial Soil, Low Humic Gley, Humic Gley and artificially drained Bog Soil were collected from a layer 0-20 cm deep. The samples were previously cultivated with radish plants that received lime, P, K, S, Cu and Zn and doses of B (0, 0.25, 0.5, 1.5, 3.0 and 6.0 mg dm-3. Before pea cultivation only K was applied (100 mg dm-3. The experimental design was totally

  18. Methods of producing continuous boron carbide fibers

    Science.gov (United States)

    Garnier, John E.; Griffith, George W.

    2015-12-01

    Methods of producing continuous boron carbide fibers. The method comprises reacting a continuous carbon fiber material and a boron oxide gas within a temperature range of from approximately 1400.degree. C. to approximately 2200.degree. C. Continuous boron carbide fibers, continuous fibers comprising boron carbide, and articles including at least a boron carbide coating are also disclosed.

  19. The interaction of boron with goethite: Experiments and CD-MUSIC modeling

    NARCIS (Netherlands)

    Goli, E.; Rahnemaie, R.; Hiemstra, T.; Malakouti, M.J.

    2011-01-01

    Boron (B) is an essential element for plants and animals growth that interacts with mineral surfaces regulating its bioavailability and mobility in soils, sediments, and natural ecosystems. The interaction with mineral surfaces is quite important because of a narrow range between boron deficiency

  20. The boron efflux transporter ROTTEN EAR is required for maize inflorescence development and fertility.

    Science.gov (United States)

    Chatterjee, Mithu; Tabi, Zara; Galli, Mary; Malcomber, Simon; Buck, Amy; Muszynski, Michael; Gallavotti, Andrea

    2014-07-01

    Although boron has a relatively low natural abundance, it is an essential plant micronutrient. Boron deficiencies cause major crop losses in several areas of the world, affecting reproduction and yield in diverse plant species. Despite the importance of boron in crop productivity, surprisingly little is known about its effects on developing reproductive organs. We isolated a maize (Zea mays) mutant, called rotten ear (rte), that shows distinct defects in vegetative and reproductive development, eventually causing widespread sterility in its inflorescences, the tassel and the ear. Positional cloning revealed that rte encodes a membrane-localized boron efflux transporter, co-orthologous to the Arabidopsis thaliana BOR1 protein. Depending on the availability of boron in the soil, rte plants show a wide range of phenotypic defects that can be fully rescued by supplementing the soil with exogenous boric acid, indicating that rte is crucial for boron transport into aerial tissues. rte is expressed in cells surrounding the xylem in both vegetative and reproductive tissues and is required for meristem activity and organ development. We show that low boron supply to the inflorescences results in widespread defects in cell and cell wall integrity, highlighting the structural importance of boron in the formation of fully fertile reproductive organs. © 2014 American Society of Plant Biologists. All rights reserved.

  1. Isotopic effect on thermal physical properties of isotopically modified boron single crystals

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Quanli [Japan Science and Technology Corporation, Kawaguchi, Saitama (Japan); Noda, Tetsuji; Suzuki, Hiroshi; Araki, Hiroshi; Numazawa, Takenori; Hirano, Toshiyuki [National Institute for Materials Science, Tsukuba, Ibaraki (Japan); Nogi, Naoyuki; Tanaka, Satoru [University of Tokyo, Department of Quantum Engineering and Systems Science, Tokyo (Japan)

    2002-04-01

    The measurement of specific heat and thermal conductivity at low temperature for isotopically modified boron single crystals was performed between 0.5 and 100K using relaxation method and steady heat flow method, respectively. The results indicate that the specific heat has obvious divergences at T<5K. At 40K, the thermal conductivity of {sup 10}B-enriched crystal is about 570 W/m{center_dot}K, which is 40% larger than that of natural boron crystal. The influence of lattice vibration modes and the isotopic effect on specific heat and thermal conductivity for isotopically modified boron are discussed. (author)

  2. AEC determines uranium enrichment policy

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    The Advisory Committee on Uranium Enrichment of the Atomic Energy Commission (AEC) has submitted a report to AEC chairman concerning the promotion of the introduction of advanced material, high performance centrifuges to replace conventional metallic drum centrifuges, and the development of next generation advanced centrifuges. The report also called for the postponement until around 1997 of the decision whether the development should be continued or not on atomic vapor laser isotope separation (AVLIS) and molecular laser isotope separation (MLIS) processes, as well as the virtual freezing of the construction of a chemical process demonstration plant. The report was approved by the AEC chairman in August. The uranium enrichment service market in the world will continue to be characterized by oversupply. The domestic situation of uranium enrichment supply-demand trend, progress of the expansion of Rokkasho enrichment plant, the trend in the development of gas centrifuge process and the basic philosophy of commercializing domestic uranium enrichment are reported. (K.I.)

  3. Effects on environment and agriculture of geothermal wastewater and boron pollution in great Menderes basin.

    Science.gov (United States)

    Koç, Cengiz

    2007-02-01

    Boron toxicity is an important disorder that can be limit plant growth on soils of arid and semi arid environments through the world. High concentrations of Boron may occur naturally in the soil or in groundwater, or be added to the soil from mining, fertilizers, or irrigation water. Off all the potential resources, irrigation water is the most important contributor to high levels of soil boron, boron is often found in high concentrations in association with saline soil and saline well water. Although of considerable agronomic importance, our understanding of Boron toxicity is rather fragment and limited. In this study, Boron content of Great Menderes River and Basin was researched. Great Menderes Basin is one of the consequence basins having agricultural potential, aspect of water and soil resources in Turkey. Great Menderes River, water resource of the basin was to be polluted by geothermal wastewater and thermal springs including Boron element. Great Menderes Basin has abundant geothermal water resources which contain high amounts of Boron and these ground water are brought to surface and used for various purposes such as power generation, heating or thermal spring and than discharged to Great Menderes River. In order to prevent Boron pollution and hence unproductively in soils, it is necessary not to discharged water with Boron to irrigation water. According to results, it was obtained that Boron content of River was as high in particular Upper Basin where there was a ground thermal water reservoir. Boron has been accumulated more than plant requirement in this area irrigated by this water. Boron content of River was relatively low in rainy months and irrigation season while it was high in dry season. Boron concentration in the River was to decrease from upstream to downstream. If it is no taken measure presently, about 130,000 ha irrigation areas which was constructed irrigation scheme in the Great Menderes basin will expose the Boron pollution and salinity

  4. Structures, stability, mechanical and electronic properties of α-boron and α*-boron

    OpenAIRE

    Chaoyu He; J. X. Zhong

    2013-01-01

    The structures, stability, mechanical and electronic properties of α-boron and a promising metastable boron phase (α*-boron) have been studied by first-principles calculations. α-boron and α*-boron consist of equivalent icosahedra B12 clusters in different connecting configurations of “3S-6D-3S” and “2S-6D-4S”, respectively. The total energy calculations show that α*-boron is less stable than α-boron but more favorable than the well-known β-boron and γ-boron at zero pressure. Both α-boron and...

  5. Boron uptake, localization, and speciation in marine brown algae.

    Science.gov (United States)

    Miller, Eric P; Wu, Youxian; Carrano, Carl J

    2016-02-01

    In contrast to the generally boron-poor terrestrial environment, the concentration of boron in the marine environment is relatively high (0.4 mM) and while there has been extensive interest in its use as a surrogate of pH in paleoclimate studies in the context of climate change-related questions, the relatively depth independent, and the generally non-nutrient-like concentration profile of this element have led to boron being neglected as a potentially biologically relevant element in the ocean. Among the marine plant-like organisms the brown algae (Phaeophyta) are one of only five lineages of photosynthetic eukaryotes to have evolved complex multicellularity. Many of unusual and often unique features of brown algae are attributable to this singular evolutionary history. These adaptations are a reflection of the marine coastal environment which brown algae dominate in terms of biomass. Consequently, brown algae are of fundamental importance to oceanic ecology, geochemistry, and coastal industry. Our results indicate that boron is taken up by a facilitated diffusion mechanism against a considerable concentration gradient. Furthermore, in both Ectocarpus and Macrocystis some boron is most likely bound to cell wall constituent alginate and the photoassimilate mannitol located in sieve cells. Herein, we describe boron uptake, speciation, localization and possible biological function in two species of brown algae, Macrocystis pyrifera and Ectocarpus siliculosus.

  6. Nitrogen enrichment of host plants has mostly beneficial effects on the life-history traits of nettle-feeding butterflies

    Science.gov (United States)

    Kurze, Susanne; Heinken, Thilo; Fartmann, Thomas

    2017-11-01

    Butterflies rank among the most threatened animal groups throughout Europe. However, current population trends differ among species. The nettle-feeding butterflies Aglais io and Aglais urticae cope successfully with the anthropogenic land-use change. Both species are assumed to be pre-adapted to higher nitrogen contents in their host plant, stinging nettle (Urtica dioica). However, it is currently unknown, whether this pre-adaptation enables both Aglais species to cope successfully or even to benefit from the excessive nitrogen availabilities in nettles growing in modern farmlands. For this reason, this study focused on the response of both Aglais species to unfertilized nettles compared to nettles receiving 150 or 300 kg N ha-1 yr-1 (i.e., common fertilizer quantities of modern-day agriculture). Fertilized nettles were characterized by higher nitrogen concentrations and lower C:N ratios compared to the control group. In both Aglais species, the individuals feeding on fertilized nettles had higher survival rates, shorter larval periods and heavier pupae and, in A. urticae also longer forewings. All these trait shifts are beneficial for the individuals, lowering their risk to die before reproduction and increasing their reproductive potential. These responses agree with the well-accepted nitrogen-limitation hypothesis predicting a positive relationship between the nitrogen content of the diet and the performance of herbivorous insects. Furthermore, our findings suggest that the increasing abundance of both Aglais species may result not only from the increasing spread of nettles into the farmland but also from changes in their quality due to the eutrophication of the landscape during recent decades.

  7. Nitrate movement and plant uptake of N in a field soil receiving 15N-enriched fertilizer

    International Nuclear Information System (INIS)

    Broadbent, F.E.; Krauter, C.

    1974-01-01

    A plot of 13.9 m 2 on Yolo fine sandy loam was fertilized with (NH 4 ) 2 SO 4 containing 8.04 atom percent excess 15 N at the rate of 112 kg N/hectare and planted first to wheat and then to corn. The plot was surrounded by a buffer zone of 405 m 2 which was treated in identical fashion except that unlabeled fertilizer was used. Porous ceramic probes for measuring soil moisture tension and for extraction of soil solution were installed depths from 15 to 180 cm. Harvested crops were analyzed for 15 N as were soil cores taken after crop harvest. Nitrate-N concentrations in the soil solution at 15 cm ranged from a maximum in March of 70 ppM, of which 39 ppM was derived from fertilizer, to a minimum of 0.2 ppM in July. The largest amount of fertilizer-derived NO 3 -N at 180 cm was 0.28 percent of that applied, contributing 0.36 ppM to the concentration at that depth. The wheat crop removed 32.3 percent of the fertilizer N and the corn crop utilized 22.8 percent. Organic and inorganic N remaining in the soil after cropping represented 32.9 percent of the applied N, leaving 12.0 percent unaccounted for. The consistently low nitrate concentrations at 180 cm suggest that this deficit was not due to leaching, and should be attributed to denitrification. (U.S.)

  8. Targeted and non-targeted boron complex formation followed by electrospray Fourier transform ion cyclotron mass spectrometry: a novel approach for identifying boron esters with natural organic matter.

    Science.gov (United States)

    Gaspar, Andras; Lucio, Marianna; Harir, Mourad; Schmitt-Kopplin, Philippe

    2011-01-01

    The formation of boron esters was investigated in peat-soluble humified materials with a detailed molecular-level description of boron-organic interactions. Thousands of individually baseline separated signals were obtained from the analysis of natural organic matter of peat samples, using Fourier transform ion cyclotron resonance mass spectrometry. This technique offers unsurpassed isotope-specific mass resolution that can lead to precise molecular formula assignments by means of mathematical data analysis and visualisation techniques, such as mass defect (Kendrick) or elemental ratio (van Krevelen) plots. The analysis of potential boron binding structures within the sample of natural organic matter was described based on prior results. Herein, we describe an algorithm that can be used to effectively distinguish and filter complexes through data obtained from boron-enriched systems with highly intricate mass spectra, such as natural organic matter.

  9. Fivefold twinned boron carbide nanowires.

    Science.gov (United States)

    Fu, Xin; Jiang, Jun; Liu, Chao; Yuan, Jun

    2009-09-09

    Chemical composition and crystal structure of fivefold twinned boron carbide nanowires have been determined by electron energy-loss spectroscopy and electron diffraction. The fivefold cyclic twinning relationship is confirmed by systematic axial rotation electron diffraction. Detailed chemical analysis reveals a carbon-rich boron carbide phase. Such boron carbide nanowires are potentially interesting because of their intrinsic hardness and high temperature thermoelectric property. Together with other boron-rich compounds, they may form a set of multiply twinned nanowire systems where the misfit strain could be continuously tuned to influence their mechanical properties.

  10. Boron in Pariette Wetland Sediments, Aquatic Vegetation & Benthic Organisms

    Science.gov (United States)

    Vasudeva, P.; Jones, C. P.; Powelson, D.; Jacobson, A. R.

    2015-12-01

    The Pariette Wetlands are comprised of 20 ponds located in Utah's Uintah Basin. Boron concentration in the Pariette Wetlands have been observed to exceed the total maximum daily limit of 750 µg L-1. Considering water flow in and out of the wetlands, boron is accumulating within the wetlands where it is sorbed to sediments and bioconcentrated by wetland plant and macro invertebrates. Since boron is an avian teratogen, an estimate of boron ingestion exposure is warranted. Samples from 3 of the 23 Pariette Wetland ponds with one pond near the inlet, one near the outlet, and one in the middle were collected. Five sampling points were designated along a 100 m transect of each pond. At each sampling point duplicate (or triplicate) samples of water, sediments, benthic organisms and wetland vegetation were collected. The sediments were collected with a KB-corer and divided at depths of 0-2 cm, 2-7 cm, and 7+ cm from the sediment surface. Sample splits were sent to the USU Bug lab for identification of invertebrate species. Whenever this transect was not intercepting vegetation, 2-3 additional sample sites were identified at the pond within stands of representative vegetation where bird nests are located. The plant parts used for boron analyses will include seeds, shoot and roots of vascular plants, as well as algae or duckweeds skimmed from the surface. Samples were processed within 2 days of collection. Water samples filtered through a 0.45 μ membrane filter were analyzed for DOC, pH and ECe. The dried and washed vegetation samples were ground and stored. The benthic organisms and macro invertebrates were netted at the water surface. The dried samples were weighed, ground and stored. Samples were weighed, oven dried and reweighed. For plant and macro-invertebrate samples, a nitric and hydrogen peroxide digestion procedure is used to dissolve environmentally available elements. The Hot Water extraction and DTPA-Sorbitol extraction were compared to estimate wetland plant

  11. Microwave digestion techniques applied to determination of boron by ICP-AES in BNCT program

    International Nuclear Information System (INIS)

    Farias, Silvia S.; Di Santo, Norberto R.; Garavaglia, Ricardo N.; Pucci, Gladys N.; Batistoni, Daniel A.; Schwint, Amanda E.

    1999-01-01

    Recently, boron neutron capture therapy (BNCT) has merged as an interesting option for the treatment of some kind of tumors where established therapies show no success. A molecular boronated species, enriched in 10 B is administrated to the subject; it localizes in malignant tissues depending the kind of tumor and localization. Therefore, a very important fact in BNCT research is the detection of boron at trace or ultra trace levels precisely and accurately. This is extremely necessary as boronated species do localize in tumoral tissue and also localize in liver, kidney, spleen, skin, membranes. By this way, before testing a boronated species, it is mandatory to determine its biodistribution in a statistically meaning population, that is related with managing of a great number of samples. In the other hand, it is necessary to exactly predict when to begin the irradiation and to determine the magnitude of radiation to obtain the desired radiological dose for a specified mean boron concentration. This involves the determination of boron in whole blood, which is related with boron concentration in the tumor object of treatment. The methodology selected for the analysis of boron in whole blood and tissues must join certain characteristics: it must not be dependant of the chemical form of boron, it has to be fast and capable to determine boron accurately and precisely in a wide range of concentrations. The design and validation of experimental models involving animals in BNCT studies and the determination of boron in blood of animals and subjects upon treatment require reliable analytical procedures to determine boron quantitatively in those biologic materials. Inductively coupled plasma-atomic emission spectrometry (ICP-AES) using pneumatic nebulization is one of the most promising methods for boron analysis, but the sample must be liquid and have low solid concentration. In our case, biological tissues and blood, it is mandatory to mineralize and/or dilute samples

  12. Nematode Indicators of Organic Enrichment

    NARCIS (Netherlands)

    Ferris, H.; Bongers, A.M.T.

    2006-01-01

    The organisms of the soil food web, dependent on resources from plants or on amendment from other sources, respond characteristically to enrichment of their environment by organic matter. Primary consumers of the incoming substrate, including bacteria, fungi, plant-feeding nematodes, annelids, and

  13. Verification experiment on the downblending of high enriched uranium (HEU) at the Portsmouth Gaseous Diffusion Plant. Digital video surveillance of the HEU feed stations

    International Nuclear Information System (INIS)

    Martinez, R.L.; Tolk, K.; Whiting, N.; Castleberry, K.; Lenarduzzi, R.

    1998-01-01

    As part of a Safeguards Agreement between the US and the International Atomic Energy Agency (IAEA), the Portsmouth Gaseous Diffusion Plant, Piketon, Ohio, was added to the list of facilities eligible for the application of IAEA safeguards. Currently, the facility is in the process of downblending excess inventory of HEU to low enriched uranium (LEU) from US defense related programs for commercial use. An agreement was reached between the US and the IAEA that would allow the IAEA to conduct an independent verification experiment at the Portsmouth facility, resulting in the confirmation that the HEU was in fact downblended. The experiment provided an opportunity for the DOE laboratories to recommend solutions/measures for new IAEA safeguards applications. One of the measures recommended by Sandia National Laboratories (SNL), and selected by the IAEA, was a digital video surveillance system for monitoring activity at the HEU feed stations. This paper describes the SNL implementation of the digital video system and its integration with the Load Cell Based Weighing System (LCBWS) from Oak Ridge National Laboratory (ORNL). The implementation was based on commercially available technology that also satisfied IAEA criteria for tamper protection and data authentication. The core of the Portsmouth digital video surveillance system was based on two Digital Camera Modules (DMC-14) from Neumann Consultants, Germany

  14. Application of pathways analyses for site performance prediction for the Gas Centrifuge Enrichment Plant and Oak Ridge Central Waste Disposal Facility

    International Nuclear Information System (INIS)

    Pin, F.G.; Oblow, E.M.

    1984-01-01

    The suitability of the Gas Centrifuge Enrichment Plant and the Oak Ridge Central Waste Disposal Facility for shallow-land burial of low-level radioactive waste is evaluated using pathways analyses. The analyses rely on conservative scenarios to describe the generation and migration of contamination and the potential human exposure to the waste. Conceptual and numerical models are developed using data from comprehensive laboratory and field investigations and are used to simulate the long-term transport of contamination to man. Conservatism is built into the analyses when assumptions concerning future events have to be made or when uncertainties concerning site or waste characteristics exist. Maximum potential doses to man are calculated and compared to the appropriate standards. The sites are found to provide adequate buffer to persons outside the DOE reservations. Conclusions concerning site capacity and site acceptability are drawn. In reaching these conclusions, some consideration is given to the uncertainties and conservatisms involved in the analyses. Analytical methods to quantitatively assess the probability of future events to occur and the sensitivity of the results to data uncertainty may prove useful in relaxing some of the conservatism built into the analyses. The applicability of such methods to pathways analyses is briefly discussed. 18 refs., 9 figs

  15. Enrichment of hexabromocyclododecanes in coastal sediments near aquaculture areas and a wastewater treatment plant in a semi-enclosed bay in South Korea.

    Science.gov (United States)

    Al-Odaini, Najat Ahmed; Shim, Won Joon; Han, Gi Myung; Jang, Mi; Hong, Sang Hee

    2015-02-01

    The contamination status and potential sources of hexabromocyclododecanes (HBCDs) in the coastal environment were investigated using sediment samples from a semi-enclosed bay in South Korea. HBCDs displayed a very different distribution profile compared to polybrominated diphenyl ethers (PBDEs) and nonylphenol, indicating different emission sources inside the bay. A strong enrichment of HBCDs was found near aquaculture areas that used expanded polystyrene (EPS) buoys, which were confirmed to be the main source of HBCDs following an analysis of buoys collected from a market and the coast. EPS buoys contained large amounts of HBCDs, with lower levels in the outside layer than inside, implying the leaching of HBCDs from the surface throughout their lifetime. This was reflected in the high levels of HBCDs measured in coastal sediments near aquaculture farms. A wastewater treatment plant was found to be an additional source of HBCDs. A dated core sample revealed an increase in HBCD concentrations over time. The isomeric profiles for most of the surface and core sediment samples were dominated by the γ-diastereoisomer. Copyright © 2014 Elsevier B.V. All rights reserved.

  16. Rice and wheat yield improvement by the application of boron in salt affected soils

    International Nuclear Information System (INIS)

    Mehdi, S.M.; Sarfraz, M.; Hassan, N.M.; Hassan, W.

    2007-01-01

    In recent past studies on wheat, rice and fruit plant showed that fairly large percentage of soils and crops are deficient in boron. Several times a question rose to study the boron responses in a cropping system to see the residual effect of boron. With the objective in mind, a field experiment was conducted at two sites in saline sodic soils to see the rice and wheat crops response to boron. Boron was applied to rice at the rate of 0.25, 0.50, 1.0, 1.5, and 2.0 Kg ha/sub -1/ as sodium tetra borate. The results showed that both paddy and straw yields increased with the increasing rates of boron and highest yield was obtained from 2 Kg ha/sub -l/. After harvesting of rice crop wheat was sown in the same layout. The treatments were divided into two equal portions. Boron was applied to one portion at the same rates as to rice while remaining half remained as such to study the residual effect of B on wheat. The results showed that grain anti straw yields increased with increasing rates of boron. In case of untreated plots to see the residual effect grain and straw yield increased with increasing rates of boron applied to rice. It was concluded that B applied to rice did show residual effect to the following wheat crop. Therefore, there is no need to apply B to following crop when B is applied to the previous crop. (author)

  17. Boron Stress Activates the General Amino Acid Control Mechanism and Inhibits Protein Synthesis

    Science.gov (United States)

    Uluisik, Irem; Kaya, Alaattin; Fomenko, Dmitri E.; Karakaya, Huseyin C.; Carlson, Bradley A.; Gladyshev, Vadim N.; Koc, Ahmet

    2011-01-01

    Boron is an essential micronutrient for plants, and it is beneficial for animals. However, at high concentrations boron is toxic to cells although the mechanism of this toxicity is not known. Atr1 has recently been identified as a boron efflux pump whose expression is upregulated in response to boron treatment. Here, we found that the expression of ATR1 is associated with expression of genes involved in amino acid biosynthesis. These mechanisms are strictly controlled by the transcription factor Gcn4 in response to boron treatment. Further analyses have shown that boron impaired protein synthesis by promoting phosphorylation of eIF2α in a Gcn2 kinase dependent manner. The uncharged tRNA binding domain (HisRS) of Gcn2 is necessary for the phosphorylation of eIF2α in the presence of boron. We postulate that boron exerts its toxic effect through activation of the general amino acid control system and inhibition of protein synthesis. Since the general amino acid control pathway is conserved among eukaryotes, this mechanism of boron toxicity may be of general importance. PMID:22114689

  18. Mathematical modeling based evaluation and simulation of boron removal in bioelectrochemical systems.

    Science.gov (United States)

    Ping, Qingyun; Abu-Reesh, Ibrahim M; He, Zhen

    2016-11-01

    Boron removal is an arising issue in desalination plants due to boron's toxicity. As an emerging treatment concept, bioelectrochemical systems (BES) can achieve potentially cost-effective boron removal by taking advantage of cathodic-produced alkali. Prior studies have demonstrated successful removal of boron in microbial desalination cells (MDCs) and microbial fuel cells (MFCs), both of which are representative BES. Herein, mathematical models were developed to further evaluate boron removal by different BES and understand the key operating factors. The models delivered very good prediction of the boron concentration in the MDC integrated with Donnan Dialysis (DD) system with the lowest relative root-mean-square error (RMSE) of 0.00%; the predication of the MFC performance generated the highest RMSE of 18.55%. The model results of salt concentration, solution pH, and current generation were well fitted with experimental data for RMSE values mostly below 10%. The long term simulation of the MDC-DD system suggests that the accumulation of salt in the catholyte/stripping solution could have a positive impact on the removal of boron due to osmosis-driven convection. The current generation in the MDC may have little influence on the boron removal, while in the MFC the current-driven electromigration can contribute up to 40% of boron removal. Osmosis-induced convection transport of boron could be the major driving force for boron removal to a low level 22.2 in order to avoid boron accumulation in the anolyte effluent. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. A new soil test for quantitative measurement of available and adsorbed boron

    Science.gov (United States)

    Boron soil tests currently in use, do not extract all plant available B but are used by relating the extractable amount of B to plant B content. There is a need to accurately measure all plant available or adsorbed B because B can be toxic to plants at elevated concentrations and can cause marked y...

  20. EURODIF: the uranium enrichment by gaseous diffusion

    International Nuclear Information System (INIS)

    Rougeau, J.P.

    1981-01-01

    During the seventies the nuclear power programme had an extremely rapid growth rate which entailed to increase the world uranium enrichment capacity. EURODIF is the largest undertaking in this field. This multinational joint venture built and now operates and enrichment plant using the gaseous diffusion process at Tricastin (France). This plant is delivering low enriched uranium since two years and has contracted about 110 million SWU's till 1990. Description, current activity and prospects are given in the paper. (Author) [pt

  1. Structural characterization of electrodeposited boron

    Indian Academy of Sciences (India)

    Raman spectroscopic examination was carried out to study the nature of bonding and the allotropic form of boron obtained after electrodeposition. The results obtained from transmission electron microscopy showed the presence of nanocrystallites embedded in an amorphous mass of boron. Raman microscopic studies ...

  2. Influence of Potassium and Boron on Some Traits in Wheat (Triticum Aestivum Cv. Darab2)

    OpenAIRE

    Mahdi Zare; Masoud Zadehbagheri; Arash Azarpanah

    2013-01-01

    The boron element is unique among the essential elements in that a narrow range in concentration can mean the difference between plant deficiency and plant toxicity. Effect of potassium on boron toxicity reduction in wheat was evaluated at Agriculture Research Station located in Jahrom, Iran, during 2009. An experiment was conducted in a factorial experiment based on Completely Randomized Design (CRD) in three replications. The treatments were four levels of B (0, 20, 40 and 60 mg) and four l...

  3. Primary Coolant pH Control for Soluble Boron-Free PWRs

    International Nuclear Information System (INIS)

    Cheon, Yang Ho; Lee, Nam Yeong; Park, Byeong Ho; Park, Seong Chan; Kim, Eun Kee

    2015-01-01

    These should be considered when evaluating and designing the operating pH program for nuclear power plants. This paper discusses the advanced water chemistry strategies to keep pace with the recent global trends related to pH control in the primary water system for soluble boron pressurized water reactor (PWR) plants. Finally, the objective of this work is to study primary coolant pH control for soluble boron-free PWR plants. This paper reviewed the advanced water chemistry strategies to keep pace with the recent global trends related to pH control in the primary water chemistry system for soluble boron PWR plants. The new chemistry trend for the primary coolant is towards adaption of the constant and elevated chemistry. Finally, this work studied primary coolant pH control for soluble boron-free PWR plants. The ammonia-based water chemistry related to pH control for boron-free PWR plants was discussed. The ammonia-based water chemistry is not recommended to avoid fluctuation of the pH value by ammonia radiolysis and to reduce C-14 production in reactor coolant from reaction with dissolved nitrogen. Also, the potassium-based water chemistry related to pH control for boron-free PWR plants was discussed. KOH has a potential as an alternative pH control agent for soluble boron-free PWR plants. The potassium-based water chemistry related to pH control is recommended for boron-free operation as follows

  4. The effects of boron management on soil microbial population and ...

    African Journals Online (AJOL)

    Administrator

    2011-06-15

    Jun 15, 2011 ... crop yield loss in China, India, Nepal and Bangladesh. (Anantawiroon et al., 1997). In Turkey, B ...... Fertil. Soils, 14: 54-60. Pollard AS, Parr AJ, Loughman BC (1977). Boron in relation to membrane functions in higher plants. J. Exp. Bot. 28: 831-841. Rhoades J (1996). Salinity: electrical conductivity and ...

  5. Functionalized boron nitride nanotubes

    Science.gov (United States)

    Sainsbury, Toby; Ikuno, Takashi; Zettl, Alexander K

    2014-04-22

    A plasma treatment has been used to modify the surface of BNNTs. In one example, the surface of the BNNT has been modified using ammonia plasma to include amine functional groups. Amine functionalization allows BNNTs to be soluble in chloroform, which had not been possible previously. Further functionalization of amine-functionalized BNNTs with thiol-terminated organic molecules has also been demonstrated. Gold nanoparticles have been self-assembled at the surface of both amine- and thiol-functionalized boron nitride Nanotubes (BNNTs) in solution. This approach constitutes a basis for the preparation of highly functionalized BNNTs and for their utilization as nanoscale templates for assembly and integration with other nanoscale materials.

  6. Boron Activated Neutron Thermometer

    Energy Technology Data Exchange (ETDEWEB)

    Lapsley, A. C. [Argonne National Lab. (ANL), Argonne, IL (United States). Instrument Research & Development

    1952-01-09

    The Brown Instrument Division of Minneapolis-Honeywell Regulator Co. have been making pilot models of boron coated neutron sensitive thermopiles, which show considerable promise of being effective indicators of slow neutron flux. Their loss in sensitivity in a year of operation in the maximum flux of CP-6 calculates to be less than 6 per cent. When used as rooftop indicators, the ratio of the signal of the two units would change by about 2 per cent in a year's time.

  7. Boron atom reactions

    International Nuclear Information System (INIS)

    Estes, R.; Tabacco, M.B.; Digiuseppe, T.G.; Davidovits, P.

    1982-01-01

    The reaction rates of atomic boron with various epoxides have been measured in a flow tube apparatus. The bimolecular rate constants, in units of cm 3 molecule -1 s -1 , are: 1,2-epoxypropane (8.6 x 10 -11 ), 1,2-epoxybutane (8.8 x 10 -11 ), 1,2,3,4-diepoxybutane (5.5 x 10 -11 ), 1-chloro-2,3-epoxypropane (5.7 x 10 -11 ), and 1,2-epoxy-3,3,3-trichloropropane (1.5 x 10 -11 ). (orig.)

  8. Boron removal by the duckweed Lemna gibba: a potential method for the remediation of boron-polluted waters.

    Science.gov (United States)

    Del-Campo Marín, Claudia M; Oron, Gideon

    2007-12-01

    Boron (B) is often found in polluted and desalinated waters. Despite its potentially environmental damaging effects, efficient treatments are lacking. The duckweed Lemna gibba has been shown to remove toxic elements from water; however, its applicability to B removal is unknown. In this study, L. gibba was examined for its tolerance to B in water and its B removal efficiency. Duckweed plants were grown in outdoor 12-day batch experiments in nutrient solution containing 0.3-10 mg B L(-1). Plant biomass production was not affected by B over the tested concentrations during the 12-day cultivation period. Boron removal and the bioconcentration factor of B in L. gibba were highest at initial B concentrations below 2 mg L(-1), and decreased as the initial B concentration increased. Boron content in the plants at the end of the experiment ranged between 930 and 1900 mg kg(-1) dry weight, and was comparable to that of wetland plants reported to be good B accumulators. Boron removal by L. gibba may therefore be a suitable option for the treatment of water containing B concentrations below 2 mg L(-1).

  9. The levels of boron-uptake proteins in roots are correlated with tolerance to boron stress in barley

    Science.gov (United States)

    Boron (B) is an essential micronutrient required for plant growth and development. Recently, two major B-uptake proteins, BOR1 and NIP5;1 have been identified and partially characterized. BOR1 is a high-affinity B transporter involved in xylem loading in roots, and NIP5;1 acts is a major boric-acid ...

  10. Boron toxicity in banana (Musa AAA) plantations of Costa Rica

    International Nuclear Information System (INIS)

    Vargas, Alfonso; Serrano, Edgardo; Arias, Fulvio; Arias M, Oscar

    2007-01-01

    A marginal, irregular and continuous necrosis was observed in the leaves of in banana plants (Musa AAA, cvs. Grande Naine and Valery), This necrosis was developed from an irregular chlorotic area, from the edge towards the internal part of the leaf blade. The central portion of the leaf kept the original green color. Soil and foliar analyses showed that symptoms were caused by high boron concentrations, probably due to excessive soil or foliage applications of the nutriment, or to the effect of very frequent applications of boron during fertigation, combined with a decrease of calcium in the leaf. (author) [es

  11. Differential response of cotton cultivars to boron toxicity

    OpenAIRE

    Harite, Ümit; Aydın, Mehmet

    2008-01-01

    A greenhouse experiment was performed to study the effects of boron (B) on growth, and B distribution in the plant parts. The reactions of cotton varieties, grown in a mixture of sand and perlite medium, were investigated in point of boron doses. The experiment was conducted with four B doses (0.5, 7.5, 15, 22.5 mg B L-1) and eight cultivars (Barut 2005, Gossipolsüz Nazilli, Gürel Bey, Nazilli 143, Nazilli 342, Nazilli 39, Nazilli-503, STN 8A) in factorial experiment design. Numbe...

  12. Boron analyses in the reactor coolant system of French PWR by acid-base titration ([B]) and ICP-MS (10B atomic %): key to NPP safety

    International Nuclear Information System (INIS)

    Jouvet, Fabien; Roux, Sylvie; Carabasse, Stephanie; Felgines, Didier

    2012-09-01

    Boron is widely used by Nuclear Power Plants and especially by EDF Pressurized Water Reactors to ensure the control of the neutron rate in the reactor coolant system and, by this way, the fission reaction. The Boron analysis is thus a major factor of safety which enables operators to guarantee the permanent control of the reactor. Two kinds of analyses carried out by EDF on the Boron species, recently upgraded regarding new method validation standards and developed to enhance the measurement quality by reducing uncertainties, will be discussed in this topic: Acid-Base titration of Boron and Boron isotopic composition by Inductively Coupled Plasma Mass Spectrometer - ICP MS. (authors)

  13. Availability of enrichment services

    International Nuclear Information System (INIS)

    Svenke, E.

    1977-01-01

    The report summarizes major uncertainties which are likely to influence future demands for uranium isotopic enrichment. Since for the next decade the development of nuclear power will be largely concerned with the increment in demand the timely need for enrichment capacity will be particularly sensitive to assumptions about growth rates. Existing worldwide capacity together with capacities under construction will be sufficient well into the 1980's. However, long decision and construction leadtime, uncertainty as to future demand as well as other factors, specifically high capital need, all of which entail financial risks, create hindrances to a timely development of increment. The adequacy of current technology is well demonstrated in plant operation and new technology is under way. Technology is, however, not freely available on a purely commercial basis. Commercial willingness, which anticipates a limited degree of financial risk, is requesting both long term back-up from the utilities that would parallel their firm decisions on the acquisition of nuclear power units, and a protective government umbrella. This situation depends on the symbiotic relationship that exists between the nuclear power generating organizations, the enrichment undertakings and the governments involved. The report accordingly stresses the need for a more cooperative approach and this, moreover, at the multinational level. There is otherwise a risk that proper resources and financing means will not be allocated to the enrichment sector. Export limitations that request the highest degree of industrial processing of nuclear fuel, i.e. the compulsory enrichment of natural uranium, do not serve the interests of overall industrial efficiency

  14. Gaseous diffusion -- the enrichment workhorse

    International Nuclear Information System (INIS)

    Shoemaker, J.E. Jr.

    1984-01-01

    Construction of the first large-scale gaseous diffusion facility was started as part of the Manhattan Project in Oak Ridge, Tennessee, in 1943. This facility, code named ''K-25,'' began operation in January 1945 and was fully on stream by September 1945. Four additional process buildings were later added in Oak Ridge as the demand for enriched uranium escalated. New gaseous diffusion plants were constructed at Paducah, Kentucky, and Portsmouth, Ohio, during this period. The three gaseous diffusion plants were the ''workhorses'' which provided the entire enriched uranium demand for the United States during the 1950s and 1960s. As the demand for enriched uranium for military purposes decreased during the early 1960s, power to the diffusion plants was curtailed to reduce production. During the 1960s, as plans for the nuclear power industry were formulated, the role of the diffusion plants gradually changed from providing highly-enriched uranium for the military to providing low-enriched uranium for power reactors

  15. Boron isotope fractionation in magma via crustal carbonate dissolution.

    Science.gov (United States)

    Deegan, Frances M; Troll, Valentin R; Whitehouse, Martin J; Jolis, Ester M; Freda, Carmela

    2016-08-04

    Carbon dioxide released by arc volcanoes is widely considered to originate from the mantle and from subducted sediments. Fluids released from upper arc carbonates, however, have recently been proposed to help modulate arc CO2 fluxes. Here we use boron as a tracer, which substitutes for carbon in limestone, to further investigate crustal carbonate degassing in volcanic arcs. We performed laboratory experiments replicating limestone assimilation into magma at crustal pressure-temperature conditions and analysed boron isotope ratios in the resulting experimental glasses. Limestone dissolution and assimilation generates CaO-enriched glass near the reaction site and a CO2-dominated vapour phase. The CaO-rich glasses have extremely low δ(11)B values down to -41.5‰, reflecting preferential partitioning of (10)B into the assimilating melt. Loss of (11)B from the reaction site occurs via the CO2 vapour phase generated during carbonate dissolution, which transports (11)B away from the reaction site as a boron-rich fluid phase. Our results demonstrate the efficacy of boron isotope fractionation during crustal carbonate assimilation and suggest that low δ(11)B melt values in arc magmas could flag shallow-level additions to the subduction cycle.

  16. Boron isotope fractionation in magma via crustal carbonate dissolution

    Science.gov (United States)

    Deegan, Frances M.; Troll, Valentin R.; Whitehouse, Martin J.; Jolis, Ester M.; Freda, Carmela

    2016-08-01

    Carbon dioxide released by arc volcanoes is widely considered to originate from the mantle and from subducted sediments. Fluids released from upper arc carbonates, however, have recently been proposed to help modulate arc CO2 fluxes. Here we use boron as a tracer, which substitutes for carbon in limestone, to further investigate crustal carbonate degassing in volcanic arcs. We performed laboratory experiments replicating limestone assimilation into magma at crustal pressure-temperature conditions and analysed boron isotope ratios in the resulting experimental glasses. Limestone dissolution and assimilation generates CaO-enriched glass near the reaction site and a CO2-dominated vapour phase. The CaO-rich glasses have extremely low δ11B values down to -41.5‰, reflecting preferential partitioning of 10B into the assimilating melt. Loss of 11B from the reaction site occurs via the CO2 vapour phase generated during carbonate dissolution, which transports 11B away from the reaction site as a boron-rich fluid phase. Our results demonstrate the efficacy of boron isotope fractionation during crustal carbonate assimilation and suggest that low δ11B melt values in arc magmas could flag shallow-level additions to the subduction cycle.

  17. Design and evaluation of experimental on line boron meter for Light Water Reactors

    International Nuclear Information System (INIS)

    Dighe, P.M.; Kamble, L.P.; Bhatnagar, P.V.; Das, D.; Swetha, M.; Patel, P.; Nathani, K.; Sen, S.K.

    2018-01-01

    Measurement of boron concentration in most PWR reactors is a critical activity, as dissolved boron is used to provide the required negative reactivity margins, whereas control rods provide control and safety actions. In nuclear plants, the usual and mandatory practice for boron concentration measurement is a manual, off line chemical titrimetry of boron. However, with current technological solutions such measurements can also be performed online to provide continuous signal to the operator. In the PWR reactors at Kudankulam present Online Boron meters (OLBM) installed are based on the imported design. Commercially OLBM are reported to be developed by Areva, Rolls-Royce etc. For indigenisation and to provide import substitute, efforts are underway to design and develop OLBMs. Towards this development an experimental set up was constructed taking inputs from Kudankulam OLBMs and by simulations using FLUKA Monte-Carlo software. The set up was experimentally evaluated for generation of calibration curves

  18. Analytical methods for the determination of boron in reactor materials programme

    International Nuclear Information System (INIS)

    Chitre, R.S.; Joshi, V.R.; Iyer, C.S.P.

    1983-01-01

    Spectrophotometric methods of determination of boron based on the complexation reaction between boric acid and protonated curcumin are briefly reviewed. Direct determination of boron in heavy water, plant leaves, copper and its alloys, and aluminium and its alloys using a modified method of Hayes and Metcalfe is described. A method for determination of boron, when its content is very low as in case of uranium metal, diuranate, uranium oxide and thorium nitrate, is also described. In this method, boron is first separated as methyl borate by distillation of the sample with methanol in acid media. The distilled ester is absorbed by hydroxide solution and boron is analysed after removal of methanol. The precision obtained is indicated. (M.G.B.)

  19. Improving the efficiency of boron application on the vineyards during NPK fertilization

    Science.gov (United States)

    Magomadov, Andy; Batukaev, Abdulmalik; Kalinitchenko, Valeriy; Minkina, Tatiana; Sushkova, Svetlana

    2017-04-01

    The effect of different doses and time of boron fertilization on growth and development of grape plants were studied on the soils of Terek-Kumskiy sands of Chechen Republic, Russian Federation. The studies have shown that sandy soils of pilot area have a low content of main macronutrients except of potassium. The boron content in the sandy soils varies within wide limits and characterizes this soil as lack of boron content especially in water-soluble boron distribution through the soil profile. It was developed a technique for roots feeding of grapes for the first time, that allows to control chemical processes the NPK uptake by plant roots. The studied process realized by implementation of optimum amount of boron in plant-available form, introduced in a certain phase of plants growth. It helps to improve the efficiency of nitrogen, phosphate, potassium using. It was found that boron improves the movement of growth substances and ascorbic acid from the leaves to the fertile parts and cannot be replaced by other nutrients. The plants need of boron throughout the growing season. Boron plays an important role in cell division and protein synthesis is an essential component of cell membranes. The use of boric acid as a fertilizer to increase the number of ovaries on grape plants, stimulating the formation of new points of stems and root growth, increased the number of shoots, improved growth, increased the sugar content of the grapes and taste of the fruit, which is a result of more active uptake of boron by grapes. The optimal dose of boron fertilization on the sandy soil and the comparative agroecological and economic evaluation of its application presented in the research. The use of boron fertilizers allowed to increase the sugar content, acidity, tasting score grapes up to 12-38%. The greatest effect of boron fertilization achieved by application to the phase start of sap flow in a dose of 3 kg/ha in the background N90P90K90. The developed technique for sandy

  20. New Small LWR Core Designs using Particle Burnable Poisons for Low Boron Concentration

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Ho Seong; Hwang, Dae Hee; Hong, Ser Gi [Kyung Hee University, Yongin (Korea, Republic of)

    2015-05-15

    The soluble boron has two major important roles in commercial PWR operations : 1) the control of the long-term reactivity to maintain criticality under normal operation, and 2) the shutdown of the reactor under accidents. However, the removal of the soluble boron gives several advantages in SMRs (Small Modular Reactor). These advantages resulted from the elimination of soluble boron include the significant simplification of nuclear power plant through the removal of pipes, pumps, and purification systems. Also, the use of soluble boron mitigates corrosion problems on the primary coolant loop. Furthermore, the soluble boron-free operation can remove an inadvertent boron dilution accident (BDA) which can lead to a significant insertion of positive reactivity. From the viewpoint of core physics, the removal of soluble boron or reduction of soluble boron concentration makes the moderator temperature coefficient (MTC) more negative. From the core design studies using new fuel assemblies, it is shown that the cores have very low critical soluble boron concentrations less than 500ppm, low peaking factors within the design targets, strong negative MTCs over cycles, and large enough shutdown margins both at BOC and EOC. However, the present cores have relatively low average discharge burnups of ∼ 30MWD/kg leading to low fuel economy because the cores use lots of non-fuel burnable poison rods to achieve very low critical boron concentrations. So, in the future, we will perform the trade-off study between the fuel discharge burnup and the boron concentrations by changing fuel assembly design and the core loading pattern.

  1. Proceedings of a specialist meeting on boron reactivity transients

    International Nuclear Information System (INIS)

    1996-01-01

    The CSNI Specialist Meeting on Boron Dilution Reactivity Transients was hosted by the Penn State University in collaboration with the US Nuclear Regulatory Commission and the TRAC Users Group. More than 70 experts from 12 OECD countries, as well as experts from Russia and other non-OECD countries attended the meeting. Thirty papers were presented in five technical sessions. The purpose of the meeting was to bring together experts involved in the different activities related to boron dilution transients. The experts came from all involved parties, including research organizations, regulatory authorities, vendors and utilities. Information was openly shared and discussed on the experimental results, plant and systems analysis, numerical analysis of mixing and probability and consequences of these transients. Regulatory background and licensing implications were also included to provide the proper frame work for the technical discussion. Each of these areas corresponded to a separate session. The meeting focused on the thermal-hydraulic aspects because of the current interest in that subject and the significant amount of new technical information being generated. Three papers of the same conference are already available in INIS as individual reports: Potential for boron dilution during small-break LOCAs in PWRs (Ref. number: 27029412); Analysis of boron dilution in a four-loop PWR (Ref. number: 27051651); Probability and consequences of a rapid boron dilution sequence in a PWR (Ref. number: 27029411)

  2. Spectrographic determination of impurities in enriched uranium solutions

    International Nuclear Information System (INIS)

    Capdevila, C.; Roca, M.

    1980-01-01

    A spectrographic procedure for the determination of trace amounts of Al, B, Ba, Be, Bi, Ca, Cd, Co, Cr, Cu, Fe, K, L i , Hg, Mn, Mo, Na, Nb, Ni, P, Pb, Ru, Sb, Sn, Sr, Ti, V, Zn, and Zr in enriched uranyl nitrate solutions from the reprocessing of spent nuclear fuels is described. After removal of uranium by either TBP or TNOA solvent extraction, the aqueous phase Is analysed by the graphite spark technique. TBP is adequate for all impurities, excepting boron and phosphorus; both of these elements can sat is factory be determined by using TNOA after the addition of mannitol to avoid boron losses. (Author) 4 refs

  3. Lattice dynamics of α boron and of boron carbide

    International Nuclear Information System (INIS)

    Vast, N.

    1999-01-01

    The atomic structure and the lattice dynamics of α boron and of B 4 C boron carbide have been studied by Density Functional Theory (D.F.T.) and Density Functional Perturbation Theory (D.F.P.T.). The bulk moduli of the unit-cell and of the icosahedron have been investigated, and the equation of state at zero temperature has been determined. In α boron, Raman diffusion and infrared absorption have been studied under pressure, and the theoretical and experimental Grueneisen coefficients have been compared. In boron carbide, inspection of the theoretical and experimental vibrational spectra has led to the determination of the atomic structure of B 4 C. Finally, the effects of isotopic disorder have been modeled by an exact method beyond the mean-field approximation, and the effects onto the Raman lines has been investigated. The method has been applied to isotopic alloys of diamond and germanium. (author)

  4. Turkey's regulatory plans for high enriched to low enriched conversion of TR-2 reactor core

    International Nuclear Information System (INIS)

    Guelol Oezdere, Oya

    2003-01-01

    Turkey is a developing country and has three nuclear facilities two of which are research reactors and one pilot fuel production plant. One of the two research reactors is TR-2 which is located in Cekmece site in Istanbul. TR-2 Reactor's core is composed of both high enriched and low enriched fuel and from high enriched to low enriched core conversion project will take place in year 2005. This paper presents the plans for drafting regulations on the safety analysis report updates for high enriched to low enriched core conversion of TR-2 reactor, the present regulatory structure of Turkey and licensing activities of nuclear facilities. (author)

  5. A new and effective approach to boron removal by using novel boron-specific fungi isolated from boron mining wastewater.

    Science.gov (United States)

    Taştan, Burcu Ertit; Çakir, Dilara Nur; Dönmez, Gönül

    2016-01-01

    Boron-resistant fungi were isolated from the wastewater of a boron mine in Turkey. Boron removal efficiencies of Penicillium crustosum and Rhodotorula mucilaginosa were detected in different media compositions. Minimal Salt Medium (MSM) and two different waste media containing molasses (WM-1) or whey + molasses (WM-2) were tested to make this process cost effective when scaled up. Both isolates achieved high boron removal yields at the highest boron concentrations tested in MSM and WM-1. The maximum boron removal yield by P. crustosum was 45.68% at 33.95 mg l(-1) initial boron concentration in MSM, and was 38.97% at 42.76 mg l(-1) boron for R. mucilaginosa, which seemed to offer an economically feasible method of removing boron from the effluents.

  6. Determination of boron in water solution by an indirect neutron activation technique from a 241Am/Be source

    International Nuclear Information System (INIS)

    Sales, H.B.

    1981-08-01

    Boron content in water solutions has been analysed by Indirect Activation Technique a twin 241 Am/Be neutron source with a source strength of 9x10 6 n/seg. The boron concentration was inferred from the measurement of the activity induced in a vanadium flux monitor. The vanadium rod was located inside the boron solution in a standart geometrical set up with respect to the neutron source. Boron concentrations in the range of 100 to 1000 ppm were determined with an overall accuracy of about 2% during a total analysis time of about 20 minutes. Eventhough the analysis is not selective for boron yet due the rapid, simple and precise nature, it is proposed for the analysis of boron in the primary coolant circuit of Nuclear Power Plants of PWR type. (Author) [pt

  7. Inhibitory effect of boron against Botrytis cinerea on table grapes and its possible mechanisms of action.

    Science.gov (United States)

    Qin, Guozheng; Zong, Yuanyuan; Chen, Qiling; Hua, Donglai; Tian, Shiping

    2010-03-31

    Boron, an essential plant micronutrient, was effective in the form of potassium tetraborate for control of postharvest gray mold caused by Botrytis cinerea on table grapes stored at room temperature or at 0 degrees C. The inhibition of fruit decay was closely correlated with boron concentrations and partially influenced by pH value of the solution. Boron strongly inhibited spore germination, germ tube elongation, and mycelial spread of B. cinerea in the culture medium. Application of boron at 1% caused the appearance of abnormal spores (disrupted) in some cases. By using propidium iodide fluorescent staining, loss of membrane integrity in B. cinerea was observed after boron treatment. Furthermore, boron led to the leakage of cellular constituents (soluble proteins and carbohydrates) from hyphae of B. cinerea. These data suggest that the mechanisms by which boron decreased gray mold decay of table grapes may be directly related to the disruption effect of boron on cell membrane of the fungal pathogen that resulted in the breakdown of the cell membrane and loss of cytoplasmic materials from the hyphae. Copyright 2009 Elsevier B.V. All rights reserved.

  8. Mathematical modeling and experimental validation of the spatial distribution of boron in the root of Arabidopsis thaliana identify high boron accumulation in the tip and predict a distinct root tip uptake function.

    Science.gov (United States)

    Shimotohno, Akie; Sotta, Naoyuki; Sato, Takafumi; De Ruvo, Micol; Marée, Athanasius F M; Grieneisen, Verônica A; Fujiwara, Toru

    2015-04-01

    Boron, an essential micronutrient, is transported in roots of Arabidopsis thaliana mainly by two different types of transporters, BORs and NIPs (nodulin26-like intrinsic proteins). Both are plasma membrane localized, but have distinct transport properties and patterns of cell type-specific accumulation with different polar localizations, which are likely to affect boron distribution. Here, we used mathematical modeling and an experimental determination to address boron distributions in the root. A computational model of the root is created at the cellular level, describing the boron transporters as observed experimentally. Boron is allowed to diffuse into roots, in cells and cell walls, and to be transported over plasma membranes, reflecting the properties of the different transporters. The model predicts that a region around the quiescent center has a higher concentration of soluble boron than other portions. To evaluate this prediction experimentally, we determined the boron distribution in roots using laser ablation-inductivity coupled plasma-mass spectrometry. The analysis indicated that the boron concentration is highest near the tip and is lower in the more proximal region of the meristem zone, similar to the pattern of soluble boron distribution predicted by the model. Our model also predicts that upward boron flux does not continuously increase from the root tip toward the mature region, indicating that boron taken up in the root tip is not efficiently transported to shoots. This suggests that root tip-absorbed boron is probably used for local root growth, and that instead it is the more mature root regions which have a greater role in transporting boron toward the shoots. © The Author 2015. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists.

  9. Diagnóstico precoce da carência de boro em castanheiro: Selecção de tecido indicador Early diagnosis of boron deficiency in chestnut: sellection of plant tissue indicator

    Directory of Open Access Journals (Sweden)

    Ester Portela

    2011-07-01

    Full Text Available O objectivo deste estudo foi identificar um tecido indicador na detecção precoce da carência de B no castanheiro, que permita a correcção atempada da carência de B. Num souto com deficiência de B instalou-se um ensaio em que se utilizaram dois níveis de B: B0, e B1 onde se aplicou 100 g de Granubor (14,6% por árvore. Colheu-se no início de Julho, quando as flores femininas estavam em plena floração, os seguintes tecidos: folhas completamente expandidas, amentilhos androgínicos e flores femininas. No período normal de colheita (Setembro, voltou-se a amostrar as folhas. Determinaram-se as concentrações de macro e micronutrientes nos diversos tecidos. As concentrações de B nos tecidos amostrados em Julho revelaram-se correlacionadas com as de B na folha colhida em Setembro. Enquanto as concentrações de B na folha, em Setembro e em Julho, estavam correlacionadas com a produção de castanha, os outros tecidos não mostraram correlação significativa. Assim, estes resultados sugerem que a folha, colhida em Julho, foi o órgão que se mostrou mais eficiente no diagnóstico precoce da carência de B.This study aims to identify a plant tissue indicator to be used in the early diagnosis of B deficiency in chestnut, which provides a tool to decide the correction measures to be applied in time to improve yield. An orchard with apparent B deficiency was selected, and two levels of B fertilization, B0 and B1- 100 g/tree of Granubor (14.6% of B, were applied. In July, when female flowers were in bloom, the following tissues were sampled: expanded leaves, androgynous catkins and female flowers. Leaves were collected again in the normal period (September and the concentrations of macro- and micronutrients in plant tissues were determined. B content in the tissues collected in July was positively correlated with B contents in leaves sampled in September. Boron concentrations in leaves, irrespective of the sampling period, were correlated

  10. Critical experiments on an enriched uranium solution system containing periodically distributed strong thermal neutron absorbers

    International Nuclear Information System (INIS)

    Rothe, R.E.

    1996-01-01

    A series of 62 critical and critical approach experiments were performed to evaluate a possible novel means of storing large volumes of fissile solution in a critically safe configuration. This study is intended to increase safety and economy through use of such a system in commercial plants which handle fissionable materials in liquid form. The fissile solution's concentration may equal or slightly exceed the minimum-critical-volume concentration; and experiments were performed for high-enriched uranium solution. Results should be generally applicable in a wide variety of plant situations. The method is called the 'Poisoned Tube Tank' because strong neutron absorbers (neutron poisons) are placed inside periodically spaced stainless steel tubes which separate absorber material from solution, keeping the former free of contamination. Eight absorbers are investigated. Both square and triangular pitched lattice patterns are studied. Ancillary topics which closely model typical plant situations are also reported. They include the effect of removing small bundles of absorbers as might occur during inspections in a production plant. Not taking the tank out of service for these inspections would be an economic advantage. Another ancillary topic studies the effect of the presence of a significant volume of unpoisoned solution close to the Poisoned Tube Tank on the critical height. A summary of the experimental findings is that boron compounds were excellent absorbers, as expected. This was true for granular materials such as Gerstley Borate and Borax; but it was also true for the flexible solid composed of boron carbide and rubber, even though only thin sheets were used. Experiments with small bundles of absorbers intentionally removed reveal that quite reasonable tanks could be constructed that would allow a few tubes at a time to be removed from the tank for inspection without removing the tank from production service

  11. Nuclear Physics meets Medicine and Biology: Boron Neutron Capture Therapy

    CERN Document Server

    F. Ballarini, F; S. Bortolussi, S; P. Bruschi, P; A.M. Clerici, A M; A. De Bari, A; P. Dionigi, P; C. Ferrari, C; M.A. Gadan, M A; N. Protti, N; S. Stella, S; C. Zonta, C; A. Zonta, A; S. Altieri, S

    2010-01-01

    BNCT is a tumour treatment based on thermal-neutron irradiation of tissues enriched with 10B, which according to the 10B(n, )7Li reaction produces particles with high Linear Energy Transfer and short range. Since this treatment can deliver a therapeutic tumour dose sparing normal tissues, BNCT represents an alternative for diffuse tumours and metastases, which show poor response to surgery and photontherapy. In 2001 and 2003, in Pavia BNCT was applied to an isolated liver, which was infused with boron, explanted, irradiated and re-implanted. A new project was then initiated for lung tumours, developing a protocol for Boron concentration measurements and performing organ-dose Monte Carlo calculations; in parallel, radiobiology studies are ongoing to characterize the BNCT effects down to cellular level. After a brief introduction, herein we will present the main activities ongoing in Pavia including the radiobiological ones, which are under investigation not only experimentally but also theoretically, basing on...

  12. Nano boron nitride flatland.

    Science.gov (United States)

    Pakdel, Amir; Bando, Yoshio; Golberg, Dmitri

    2014-02-07

    Recent years have witnessed many breakthroughs in research on two-dimensional (2D) nanomaterials, among which is hexagonal boron nitride (h-BN), a layered material with a regular network of BN hexagons. This review provides an insight into the marvellous nano BN flatland, beginning with a concise introduction to BN and its low-dimensional nanostructures, followed by an overview of the past and current state of research on 2D BN nanostructures. A comprehensive review of the structural characteristics and synthetic routes of BN monolayers, multilayers, nanomeshes, nanowaves, nanoflakes, nanosheets and nanoribbons is presented. In addition, electronic, optical, thermal, mechanical, magnetic, piezoelectric, catalytic, ecological, biological and wetting properties, applications and research perspectives for these novel 2D nanomaterials are discussed.

  13. A study on the nuclear characteristics of enriched gadolinia burnable absorber rods; the first year (2000) report

    International Nuclear Information System (INIS)

    Zee, Sung Quun; Lee, C.C.; Song, J. S.; Cho, B. O.; Joo, H. G.; Park, S. Y.; Kim, H. Y.; Cho, J. Y.; Kim, K. S.

    2001-04-01

    An analysis model using MICBURN-3/CASMO-3 is established for the enriched gadolinia burnable absorber rods. A homogenized cross section editing code, PROLOG, is modified so that it can handle such a fuel assembly that includes two different types of gadolinia rods. Study shows that Gd-155 and Gd-157 are almost same in suppressing the excess reactivity and it is recommended to enrich both odd number isotopes, Gd-155 and Gd-157. It is estimated that the cycle length increases by 2 days if enriched gadolinia rods are used in the commercial nuclear power plant such as YGN-3 of which the cycle length is assumed 2 years. For the advanced integral reactor SMART in which ultra long cycle length and soluble boron-free operation concept is applied, natural gadolinia burnable absorber rods fail to control the excess reactivity. On the other hand, enriched gadolinia rods are successful in controling the excess reactivity. To minimize power peakings, various placements of gadolinia rods are tested. Also initial reactivity holddown and gadolinia burnout time are parametrized with respect to the number of gadolinia rods and gadolinia weight fractions

  14. Metal interactions with boron clusters

    International Nuclear Information System (INIS)

    Grimes, R.N.

    1982-01-01

    This book presents information on the following topics: the structural and bonding features of metallaboranes and metallacarboranes; transition-metal derivatives of nido-boranes and some related species; interactions of metal groups with the octahydrotriborate (1-) anion, B 3 H 8 ; metallaboron cage compounds of the main group metals; closo-carborane-metal complexes containing metal-carbon and metal-boron omega-bonds; electrochemistry of metallaboron cage compounds; and boron clusters with transition metal-hydrogen bonds

  15. Boron diffusion in silicon devices

    Science.gov (United States)

    Rohatgi, Ajeet; Kim, Dong Seop; Nakayashiki, Kenta; Rounsaville, Brian

    2010-09-07

    Disclosed are various embodiments that include a process, an arrangement, and an apparatus for boron diffusion in a wafer. In one representative embodiment, a process is provided in which a boric oxide solution is applied to a surface of the wafer. Thereafter, the wafer is subjected to a fast heat ramp-up associated with a first heating cycle that results in a release of an amount of boron for diffusion into the wafer.

  16. Boron Fullerenes: A First-Principles Study

    Directory of Open Access Journals (Sweden)

    Gonzalez Szwacki Nevill

    2007-01-01

    Full Text Available AbstractA family of unusually stable boron cages was identified and examined using first-principles local-density functional method. The structure of the fullerenes is similar to that of the B12icosahedron and consists of six crossing double-rings. The energetically most stable fullerene is made up of 180 boron atoms. A connection between the fullerene family and its precursors, boron sheets, is made. We show that the most stable boron sheets are not necessarily precursors of very stable boron cages. Our finding is a step forward in the understanding of the structure of the recently produced boron nanotubes.

  17. Analysis of boron dilution in a four-loop PWR

    Energy Technology Data Exchange (ETDEWEB)

    Sun, J.G.; Sha, W.T. [Argonne National Lab., IL (United States)

    1995-03-01

    Thermal mixing and boron dilution in a pressurized water reactor were analyzed with COMMIX codes. The reactor system was the four-loop Zion reactor. Two boron dilution scenarios were analyzed. In the first scenario, the plant is in cold shutdown and the reactor coolant system has just been filled after maintenance on the steam generators. To flush the air out of the steam generator tubes, a reactor coolant pump (RCP) is started, with the water in the pump suction line devoid of boron and at the same temperature as the coolant in the system. In the second scenario, the plant is at hot standby and the reactor coolant system has been heated to operating temperature after a long outage. It is assumed that an RCP is started, with the pump suction line filled with cold unborated water, forcing a slug of diluted coolant down the downcomer and subsequently through the reactor core. The subsequent transient thermal mixing and boron dilution that would occur in the reactor system is simulated for these two scenarios. The reactivity insertion rate and the total reactivity are evaluated and a sensitivity study is performed to assess the accuracy of the numerical modeling of the geometry of the reactor coolant system.

  18. Analysis of boron dilution in a four-loop PWR

    Energy Technology Data Exchange (ETDEWEB)

    Sun, J.G.; Sha, W.T.

    1995-12-31

    Thermal mixing and boron dilution in a pressurized water reactor were analyzed with COMMIX codes. The reactor system was the four loop Zion reactor. Two boron dilution scenarios were analyzed. In the first scenario, the plant is in cold shutdown and the reactor coolant system has just been filled after maintenance on the steam generators. To flush the air out of the steam generator tubes, a reactor coolant pump (RCP) is started, with the water in the pump suction line devoid of boron and at the same temperature as the coolant in the system. In the second scenario, the plant is at hot standby and the reactor coolant system has been heated up to operating temperature after a long outage. It is assumed that an RCP is started, with the pump suction line filled with cold unborated water, forcing a slug of diluted coolant down the downcomer and subsequently through the reactor core. The subsequent transient thermal mixing and boron dilution that would occur in the reactor system is simulated for these two scenarios. The reactivity insertion rate and the total reactivity are evaluated.

  19. The Boron Efflux Transporter ROTTEN EAR Is Required for Maize Inflorescence Development and Fertility[C][W][OPEN

    Science.gov (United States)

    Chatterjee, Mithu; Tabi, Zara; Galli, Mary; Malcomber, Simon; Buck, Amy; Muszynski, Michael; Gallavotti, Andrea

    2014-01-01

    Although boron has a relatively low natural abundance, it is an essential plant micronutrient. Boron deficiencies cause major crop losses in several areas of the world, affecting reproduction and yield in diverse plant species. Despite the importance of boron in crop productivity, surprisingly little is known about its effects on developing reproductive organs. We isolated a maize (Zea mays) mutant, called rotten ear (rte), that shows distinct defects in vegetative and reproductive development, eventually causing widespread sterility in its inflorescences, the tassel and the ear. Positional cloning revealed that rte encodes a membrane-localized boron efflux transporter, co-orthologous to the Arabidopsis thaliana BOR1 protein. Depending on the availability of boron in the soil, rte plants show a wide range of phenotypic defects that can be fully rescued by supplementing the soil with exogenous boric acid, indicating that rte is crucial for boron transport into aerial tissues. rte is expressed in cells surrounding the xylem in both vegetative and reproductive tissues and is required for meristem activity and organ development. We show that low boron supply to the inflorescences results in widespread defects in cell and cell wall integrity, highlighting the structural importance of boron in the formation of fully fertile reproductive organs. PMID:25035400

  20. Enriched boric acid as an optimized neutron absorber in the EPR primary coolant

    International Nuclear Information System (INIS)

    Cosse, Christelle; Jolivel, Fabienne; Berger, Martial

    2012-09-01

    This paper focuses on one of the most important EPR PWR reactor design optimizations, through primary coolant conditioning by enriched boric acid (EBA). On PWRs throughout the world, boric acid has already been implemented in primary coolant and associated auxiliary systems for criticality control, due to its high Boron 10 neutron absorption cross section. Boric acid also allows primary coolant pH 300C control in combination with lithium hydroxide in many PWRs. The boric acid employed in the majority of existing PWRs is the 'natural' one, with a typical isotopic atomic abundance in Boron 10 about 19.8 at.%. However, EPR requirements for neutron management are more important, due to its fully optimized design compared to older PWRs. From the boron point of view, it means that criticality could be controlled either by increased 'natural' Boron concentrations or by using EBA. Comparatively to 'natural' boric acid, EBA allows for: - the use of smaller storage volumes for an identical total Boron concentration, or lower total Boron concentration if the tank volumes are kept identical. The latter also reduces the risks of boric acid crystallization, in spite of increased neutron-absorbing properties - the application of an evolutionary chemistry operating regime called Advanced pH Control, making it possible to maintain a constant pH 300C value at 7.2 in the primary coolant at nominal conditions throughout entire cycles. This optimized stability of pH 300C will contribute to reduce the consequences of contamination of the reactor coolant system by corrosion products, and consequently, all related issues - the reduction of borated liquid wastes, thanks to maximal recycling resulting from EPR design. The increased design costs associated with EBA are consequently compensated by a reduced total consumption of this chemical. Therefore, the basic design choice for the EPR is the use of EBA. For the Flamanville 3 EPR, according to the above

  1. Genotypic effects on boron concentrations and response on boron fertilization in maize inbred lines

    Directory of Open Access Journals (Sweden)

    Andrić Luka

    2016-01-01

    Full Text Available Boron (B deficiency in maize can result in barren cobs attributed to silks being nonreceptive which is particularly important for the female parent in seed production. The objectives of this study were 1 to investigate genotypic differences among nine female inbred lines used in seed production for B concentration in ear-leaf and grain, as well as for grain yield and moisture in a three-year experiment (2006-2008 and 2 to determine response and relations among the traits when four of the female inbred lines are treated by foliar boron fertilization - three times in 10-days interval with 0.5% Solubor solution (17.5% B during one growing season (2008. The investigations were performed on Experimental field of Agricultural Institute Osijek, (soil type: eutrical cambisol. Highly significant differences among the nine female inbred lines were detected for B concentration in ear-leaf (from 14.7 to 46.7 mg B kg-1 and grain (from 1.20 to 2.06 mg B kg-1 as well as for grain yield (from 3.33 to 4.83 t ha-1 and grain moisture (from 14.7% to 26.6%. However, there were also significant effects of growing season and the genotype by environment interaction for all four traits. Positive and moderate correlations were found between the boron status in plant and grain yield. Although B concentrations were considerably increased by foliar boron fertilization (averages 41.7 and 125.3 mg B kg-1 in leaves, 1.79 and 2.80 mg B kg-1 in grain, for control and fertilization, respectively, in general grain yield differences among treatments were non-significant. (averages 5.21 and 5.15 t ha-1, respectively.

  2. Germanium Does Not Substitute for Boron in Cross-Linking of Rhamnogalacturonan II in Pumpkin Cell Walls1

    Science.gov (United States)

    Ishii, Tadashi; Matsunaga, Toshiro; Iwai, Hiroaki; Satoh, Shinobu; Taoshita, Junji

    2002-01-01

    Boron (B)-deficient pumpkin (Cucurbita moschata Duchesne) plants exhibit reduced growth, and their tissues are brittle. The leaf cell walls of these plants contain less than one-half the amount of borate cross-linked rhamnogalacturonan II (RG-II) dimer than normal plants. Supplying germanium (Ge), which has been reported to substitute for B, to B-deficient plants does not restore growth or reduce tissue brittleness. Nevertheless, the leaf cell walls of the Ge-treated plants accumulated considerable amounts of Ge. Dimeric RG-II (dRG-II) accounted for between 20% and 35% of the total RG-II in the cell walls of the second to fourth leaves from Ge-treated plants, but only 2% to 7% of the RG-II was cross-linked by germanate (dRG-II-Ge). The ability of RG-II to form a dimer is not reduced by Ge treatment because approximately 95% of the monomeric RG-II generated from the walls of Ge-treated plants is converted to dRG-II-Ge in vitro in the presence of germanium oxide and lead acetate. However, dRG-II-Ge is unstable and is converted to monomeric RG-II when the Ge is removed. Therefore, the content of dRG-II-Ge and dRG-II-B described above may not reflect the actual ratio of these in muro. 10B-Enriched boric acid and Ge are incorporated into the cell wall within 10 min after their foliar application to B-deficient plants. Foliar application of 10B but not Ge results in an increase in the proportion of dRG-II in the leaf cell wall. Taken together, our results suggest that Ge does not restore the growth of B-deficient plants. PMID:12481079

  3. Analysis of variation in few-group cross section behavior subjected to burnup and boron concentration

    International Nuclear Information System (INIS)

    Zhang Zongyao; Li Dongsheng.

    1986-01-01

    The paper analyzes the variations of few-group cross section behavior in neutron diffusion subjected to fuel burnup and critical boron concentration in a core. The influences of the behavior on the core excess reactivity, crirical boron concentration, power distribution and the yield of isotopes are also analyzed. A reactor core of samll-medium-sized nuclear power plant is analyzed as an example

  4. Use of water as displacing agent in ion exchange chromatographic separation of isotope of boron using weak base ion exchange resin

    International Nuclear Information System (INIS)

    Sharma, B.K.; Mohanakrishnan, G.; Anand Babu, C.; Krishna Prabhu, R.

    2008-01-01

    Experiments were undertaken to study the feasibility of using weakly basic anion exchange resin for enrichment of isotopes of boron by ion exchange chromatography and water as eluent. The results of experiments carried out to determine total chloride capacity (TCC), strong base capacity (SBC) of the resin at different concentrations of boric acid and enrichment profiles are reported in this paper. (author)

  5. Future boronated molecules for neutron capture therapy

    International Nuclear Information System (INIS)

    Soloway, A.H.; Alam, F.; Barth, R.F.

    1986-01-01

    The ability of several boron compounds to localize in tumor cells is examined. A number of first and second generation compounds which were not synthesized specifically for localization are described. Among these are the boron hydrides and boranes. A third generation of boron compounds are designed for selective localization. These fall into two groups: relatively small organic compounds and boronated antibodies, both of which are discussed here

  6. Lattice vibrations in α-boron

    International Nuclear Information System (INIS)

    Richter, W.

    1976-01-01

    α-rhombohedral boron is the simplest boron modification, with only 12 atoms per unit cell. The boron atoms are arranged in B 12 icosahedra, which are centered at the lattice points of a primitive rhombohedral lattice. The icosahedra are slightly deformed, as the five-fold symmetry of the ideal icosahedron is incompatible with any crystal structure. The lattice dynamics of α-boron are discussed in terms of the model developed by Weber and Thorpe. (Auth.)

  7. Synthesis of oligomeric boron-containing phospolyols

    International Nuclear Information System (INIS)

    Bondarenko, S.N.; Khokhlova, T.V.; Orlova, S.A.; Tuzhikov, O.I.

    2006-01-01

    Structure is investigated and reactivity of oligomeric boron-containing phospolyols is studied. Oligomeric boron-containing compound interacts with ethylene glycol, diethylene glycol, glycerol, 1,4-butandiol with formation of linear boron-containing phospolyols. Reactions proceed in noncatalytic conditions with stoichiometric quantities of reagents at 170-200 Deg C in inert gas media. Boron-containing phospolyols are viscous uncolored liquids, their physicochemical characteristics are represented [ru

  8. New Experimental Setup for Boron Isotopes Separation by the Laser Assisted Retardation of Condensation Method.

    Science.gov (United States)

    Lyakhov, Konstantin; Lee, Heon-Ju

    2015-11-01

    Demand in isotopically pure boron is steadily growing in industry and medicine. It makes necessary to search for cheaper ways of isotopes production. We propose a new experimental setup design for boron isotope separation by laser assisted retardation of condensation (SILARC) method based on an energy efficiency use relevant optimization method. This optimization method is based on the transport model for rarefied gas flow dynamics in laser field with frequency tuned for excitation of specific isotopomer. Because product cut and enrichment factor corresponding to the optimal conditions are rather small, target isotopomers should be recovered iteratively.

  9. Neutron Detection using Amorphous Boron-Carbide Hetero-Junction Diodes

    Science.gov (United States)

    2012-03-22

    states. Special nuclear material as defined by Title I of the Atomic Energy Act of 1954 includes Pu, 233U, and uranium enriched in the isotopes 233U...NEUTRON DETECTION USING AMORPHOUS BORON -CARBIDE HETERO-JUNCTION DIODES THESIS Thomas P. McQuary, Major, USA AFIT/NUCL/ENP/12-M06 DEPARTMENT OF THE...is not subject to copyright protection in the United States. AFIT/NUCL/ENP/12-M06 NEUTRON DETECTION USING AMORPHOUS BORON -CARBIDE HETERO-JUNCTION

  10. Re-assessment of plant carbon dynamics at the Duke free-air CO(2) enrichment site: interactions of atmospheric [CO(2)] with nitrogen and water availability over stand development.

    Science.gov (United States)

    McCarthy, Heather R; Oren, Ram; Johnsen, Kurt H; Gallet-Budynek, Anne; Pritchard, Seth G; Cook, Charles W; Ladeau, Shannon L; Jackson, Robert B; Finzi, Adrien C

    2010-01-01

    *The potential for elevated [CO(2)]-induced changes to plant carbon (C) storage, through modifications in plant production and allocation of C among plant pools, is an important source of uncertainty when predicting future forest function. Utilizing 10 yr of data from the Duke free-air CO(2) enrichment site, we evaluated the dynamics and distribution of plant C. *Discrepancy between heights measured for this study and previously calculated heights required revision of earlier allometrically based biomass determinations, resulting in higher (up to 50%) estimates of standing biomass and net primary productivity than previous assessments. *Generally, elevated [CO(2)] caused sustained increases in plant biomass production and in standing C, but did not affect the partitioning of C among plant biomass pools. Spatial variation in net primary productivity and its [CO(2)]-induced enhancement was controlled primarily by N availability, with the difference between precipitation and potential evapotranspiration explaining most interannual variability. Consequently, [CO(2)]-induced net primary productivity enhancement ranged from 22 to 30% in different plots and years. *Through quantifying the effects of nutrient and water availability on the forest productivity response to elevated [CO(2)], we show that net primary productivity enhancement by elevated [CO(2)] is not uniform, but rather highly dependent on the availability of other growth resources.

  11. Boron evaporation in thermally-driven seawater desalination: Effect of temperature and operating conditions.

    Science.gov (United States)

    Alpatova, A; Alsaadi, A; Ghaffour, N

    2018-06-05

    The volatilization of boron in thermal desalination processes, namely multi-stage flash (MSF) and air-gap membrane distillation (AGMD) was investigated for the first time. This phenomenon was observed at feed temperatures above 55 °C in both studied processes. In simulated MSF process with two feeds, model boric acid and Red Sea water, boron concentration in distillate increased with feed temperature increase from 55 °C to 104 °C because of the increase in boric acid vapor pressure. Salinity and pH were the main factors controlling boron evaporation. The achieved boron concentrations in simulated MSF process were consistent with those measured in distillate samples collected from commercial MSF plants. The AGMD process also revealed a strong influence of operating temperature on boron removal. However, unlike MSF process, the boron concentration in AGMD permeate decreased with the feed temperature increase from 55 °C to 80 °C due probably to increase in vapor production and corresponding permeate dilution. When AGMD was operated in concentrating mode at a constant feed temperature of 80 °C, permeate boron concentration increased with process time due to concentration polarization and membrane fouling. A 10% flux decline observed after 21 h was attributed to CaCO 3 scaling on the membrane surface. Copyright © 2018 Elsevier B.V. All rights reserved.

  12. Boron evaporation in thermally-driven seawater desalination: Effect of temperature and operating conditions

    KAUST Repository

    Alpatova, Alla

    2018-03-26

    The volatilization of boron in thermal desalination processes, namely multi-stage flash (MSF) and air-gap membrane distillation (AGMD) was investigated for the first time. This phenomenon was observed at feed temperatures above 55 °C in both studied processes. In simulated MSF process with two feeds, model boric acid and Red Sea water, boron concentration in distillate increased with feed temperature increase from 55 °C to 104 °C because of the increase in boric acid vapor pressure. Salinity and pH were the main factors controlling boron evaporation. The achieved boron concentrations in simulated MSF process were consistent with those measured in distillate samples collected from commercial MSF plants. The AGMD process also revealed a strong influence of operating temperature on boron removal. However, unlike MSF process, the boron concentration in AGMD permeate decreased with the feed temperature increase from 55 °C to 80 °C due probably to increase in vapor production and corresponding permeate dilution. When AGMD was operated in concentrating mode at a constant feed temperature of 80 °C, permeate boron concentration increased with process time due to concentration polarization and membrane fouling. A 10% flux decline observed after 21 h was attributed to CaCO scaling on the membrane surface.

  13. Structures, stability, mechanical and electronic properties of a-boron and its twined brother a*-boron

    OpenAIRE

    He, Chaoyu; Zhong, Jianxin

    2013-01-01

    The structures, stability, mechanical and electronic properties of a-boron and its twined brother a*-boron have been studied by first-principles calculations. Both a-boron and a*-boron consist of equivalent icosahedra B12 clusters in different connecting configurations of "3S-6D-3S" and "2S-6D-4S", respectively. The total energy calculations show that a*-boron is less stable than a-boron but more favorable than beta-boron and Gamma-boron at zero pressure. Both a-boron and a*-boron are confirm...

  14. Other enrichment related contracts

    International Nuclear Information System (INIS)

    Hall, J.C.

    1978-01-01

    In addition to long-term enrichment contracts, DOE has other types of contracts: (1) short-term, fixed-commitment enrichment contract; (2) emergency sales agreement for enriched uranium; (3) feed material lease agreement; (4) enriched uranium storage agreement; and (5) feed material usage agreement

  15. Boron steel. I Part. Preparation

    International Nuclear Information System (INIS)

    Jaraiz Franco, E.; Esteban Hernandez, J. A.

    1960-01-01

    With the advent of the first nuclear reactors arise the need for control rods and shielding duties for some types of radiations. One of the materials used for this purpose has been the high boron steel. This paper describes the melting and casting procedures employed for the production, at laboratory scale, of steels with Boron content ranging from 1 to 4 per cent, as well as the metallographic and X-Ray techniques used for the identification of the present phases. The electrolytic technique employed for the isolation of the Fe 2 B phase and its subsequent X-Ray identification has proved to be satisfactory. (Author) 11 refs

  16. Thermal conductivity of boron carbides

    Science.gov (United States)

    Wood, C.; Emin, D.; Gray, P. E.

    1985-01-01

    Knowledge of the thermal conductivity of boron carbide is necessary to evaluate its potential for high-temperature thermoelectric energy conversion applications. Measurements have been conducted of the thermal diffusivity of hot-pressed boron carbide BxC samples as a function of composition (x in the range from 4 to 9), temperature (300-1700 K), and temperature cycling. These data, in concert with density and specific-heat data, yield the thermal conductivities of these materials. The results are discussed in terms of a structural model that has been previously advanced to explain the electronic transport data. Some novel mechanisms for thermal conduction are briefly discussed.

  17. New Icosahedral Boron Carbide Semiconductors

    Science.gov (United States)

    Echeverria Mora, Elena Maria

    Novel semiconductor boron carbide films and boron carbide films doped with aromatic compounds have been investigated and characterized. Most of these semiconductors were formed by plasma enhanced chemical vapor deposition. The aromatic compound additives used, in this thesis, were pyridine (Py), aniline, and diaminobenzene (DAB). As one of the key parameters for semiconducting device functionality is the metal contact and, therefore, the chemical interactions or band bending that may occur at the metal/semiconductor interface, X-ray photoemission spectroscopy has been used to investigate the interaction of gold (Au) with these novel boron carbide-based semiconductors. Both n- and p-type films have been tested and pure boron carbide devices are compared to those containing aromatic compounds. The results show that boron carbide seems to behave differently from other semiconductors, opening a way for new analysis and approaches in device's functionality. By studying the electrical and optical properties of these films, it has been found that samples containing the aromatic compound exhibit an improvement in the electron-hole separation and charge extraction, as well as a decrease in the band gap. The hole carrier lifetimes for each sample were extracted from the capacitance-voltage, C(V), and current-voltage, I(V), curves. Additionally, devices, with boron carbide with the addition of pyridine, exhibited better collection of neutron capture generated pulses at ZERO applied bias, compared to the pure boron carbide samples. This is consistent with the longer carrier lifetimes estimated for these films. The I-V curves, as a function of external magnetic field, of the pure boron carbide films and films containing DAB demonstrate that significant room temperature negative magneto-resistance (> 100% for pure samples, and > 50% for samples containing DAB) is possible in the resulting dielectric thin films. Inclusion of DAB is not essential for significant negative magneto

  18. Chemical separation of boron isotopes

    International Nuclear Information System (INIS)

    Palko, A.A.

    1978-06-01

    This is the final report of the research performed at ORNL on the chemical fractionation of boron isotopes between BF 3 gas and the liquid molecular addition compounds of BF 3 . Thirty compounds were studied, ten of them in detail. Graphs and equations are given for variation of isotopic equilibrium constant, vapor pressure, and BF 3 solubility as a function of temperature. Rate of isotopic exchange and melting points were determined. Several of the compounds are likely candidates for use in a gas-liquid countercurrent exchange system for large-scale separation of boron isotopes. 23 figs, 53 tables, 39 references

  19. Chemical separation of boron isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Palko, A.A.

    1978-06-01

    This is the final report of the research performed at ORNL on the chemical fractionation of boron isotopes between BF/sub 3/ gas and the liquid molecular addition compounds of BF/sub 3/. Thirty compounds were studied, ten of them in detail. Graphs and equations are given for variation of isotopic equilibrium constant, vapor pressure, and BF/sub 3/ solubility as a function of temperature. Rate of isotopic exchange and melting points were determined. Several of the compounds are likely candidates for use in a gas-liquid countercurrent exchange system for large-scale separation of boron isotopes. 23 figs, 53 tables, 39 references.

  20. Boron cycling in subduction zones

    OpenAIRE

    Palmer, Martin R.

    2017-01-01

    Subduction zones are geologically dramatic features, with much of the drama being driven by the movement of water. The “light and lively” nature of boron, coupled with its wide variations in isotopic composition shown by the different geo-players in this drama, make it an ideal tracer for the role and movement of water during subduction. The utility of boron ranges from monitoring how the fluids that are expelled from the accretionary prism influence seawater chemistry, to the subduction of c...

  1. Perennial soybean seeds coated with high doses of boron and zinc ...

    African Journals Online (AJOL)

    The objective of this work was to study combinations of high doses of boron (B) and zinc (Zn) in the recoating of perennial soybean seeds, in order to provide these nutrients to the future plants. The physical, physiological and nutritional characteristics of the coated seeds and initial development of plants in a greenhouse ...

  2. Effects of long-term exposure to elevated CO(2) conditions in slow-growing plants using a (12)C-enriched CO(2)-labelling technique.

    Science.gov (United States)

    Pardo, Antoni; Aranjuelo, Iker; Biel, Carmen; Savé, Robert; Azcón-Bieto, Joaquim; Nogués, Salvador

    2009-01-01

    Despite their relevancy, long-term studies analyzing elevated CO(2) effect in plant production and carbon (C) management on slow-growing plants are scarce. A special chamber was designed to perform whole-plant above-ground gas-exchange measurements in two slow-growing plants (Chamaerops humilis and Cycas revoluta) exposed to ambient (ca. 400 micromol mol(-1)) and elevated (ca. 800 micromol mol(-1)) CO(2) conditions over a long-term period (20 months). The ambient isotopic (13)C/(12)C composition (delta(13)C) of plants exposed to elevated CO(2) conditions was modified (from ca. -12.8 per thousand to ca. -19.2 per thousand) in order to study carbon allocation in leaf, shoot and root tissues. Elevated CO(2) increased plant growth by ca. 45% and 60% in Chamaerops and Cycas, respectively. The whole-plant above-ground gas-exchange determinations revealed that, in the case of Chamaerops, elevated CO(2) decreased the photosynthetic activity (determined on leaf area basis) as a consequence of the limited ability to increase C sink strength. On the other hand, the larger C sink strength (reflected by their larger CO(2) stimulatory effect on dry mass) in Cycas plants exposed to elevated CO(2) enabled the enhancement of their photosynthetic capacity. The delta(13)C values determined in the different plant tissues (leaf, shoot and root) suggest that Cycas plants grown under elevated CO(2) had a larger ability to export the excess leaf C, probably to the main root. The results obtained highlighted the different C management strategies of both plants and offered relevant information about the potential response of two slow-growing plants under global climate change conditions. Copyright (c) 2008 John Wiley & Sons, Ltd.

  3. Boron Nitride Nanoribbons from Exfoliation of Boron Nitride Nanotubes

    Science.gov (United States)

    Hung, Ching-Cheh; Hurst, Janet; Santiago, Diana

    2017-01-01

    Two types of boron nitride nanotubes (BNNTs) were exfoliated into boron nitride nanoribbons (BNNR), which were identified using transmission electron microscopy: (1) commercial BNNTs with thin tube walls and small diameters. Tube unzipping was indicated by a large decrease of the sample's surface area and volume for pores less than 2 nm in diameter. (2) BNNTs with large diameters and thick walls synthesized at NASA Glenn Research Center. Here, tube unraveling was indicated by a large increase in external surface area and pore volume. For both, the exfoliation process was similar to the previous reported method to exfoliate commercial hexagonal boron nitride (hBN): Mixtures of BNNT, FeCl3, and NaF (or KF) were sequentially treated in 250 to 350 C nitrogen for intercalation, 500 to 750 C air for exfoliation, and finally HCl for purification. Property changes of the nanosized boron nitride throughout this process were also similar to the previously observed changes of commercial hBN during the exfoliation process: Both crystal structure (x-ray diffraction data) and chemical properties (Fourier-transform infrared spectroscopy data) of the original reactant changed after intercalation and exfoliation, but most (not all) of these changes revert back to those of the reactant once the final, purified products are obtained.

  4. Synthesis of boron nitride from boron containing poly (vinyl alcohol ...

    Indian Academy of Sciences (India)

    A ceramic precursor, prepared by condensation reaction from poly(vinyl alcohol) (PVA) and boric acid (H3BO3) in 1:1, 2:1 and 4:1 molar ratios, was synthesized as low temperature synthesis route for boron nitride ceramic. Samples were pyrolyzed at 850°C in nitrogen atmosphere followed by characterization using Fourier ...

  5. Boron analysis and boron imaging in biological materials for Boron Neutron Capture Therapy (BNCT).

    Science.gov (United States)

    Wittig, Andrea; Michel, Jean; Moss, Raymond L; Stecher-Rasmussen, Finn; Arlinghaus, Heinrich F; Bendel, Peter; Mauri, Pier Luigi; Altieri, Saverio; Hilger, Ralf; Salvadori, Piero A; Menichetti, Luca; Zamenhof, Robert; Sauerwein, Wolfgang A G

    2008-10-01

    Boron Neutron Capture Therapy (BNCT) is based on the ability of the stable isotope 10B to capture neutrons, which leads to a nuclear reaction producing an alpha- and a 7Li-particle, both having a high biological effectiveness and a very short range in tissue, being limited to approximately one cell diameter. This opens the possibility for a highly selective cancer therapy. BNCT strongly depends on the selective uptake of 10B in tumor cells and on its distribution inside the cells. The chemical properties of boron and the need to discriminate different isotopes make the investigation of the concentration and distribution of 10B a challenging task. The most advanced techniques to measure and image boron are described, both invasive and non-invasive. The most promising approach for further investigation will be the complementary use of the different techniques to obtain the information that is mandatory for the future of this innovative treatment modality.

  6. Boron-enhanced diffusion of boron from ultralow-energy boron implantation

    International Nuclear Information System (INIS)

    Agarwal, A.; Eaglesham, D.J.; Gossmann, H.J.; Pelaz, L.; Herner, S.B.; Jacobson, D.C.

    1998-01-01

    The authors have investigated the diffusion enhancement mechanism of BED (boron enhanced diffusion), wherein the boron diffusivity is enhanced three to four times over the equilibrium diffusivity at 1,050 C in the proximity of a silicon layer containing a high boron concentration. It is shown that BED is associated with the formation of a fine-grain polycrystalline silicon boride phase within an initially amorphous Si layer having a high B concentration. For 0.5 keV B + , the threshold implantation dose which leads to BED lies between 3 x 10 14 and of 1 x 10 15 /cm -2 . Formation of the shallowest possible junctions by 0.5 keV B + requires that the implant dose be kept lower than this threshold

  7. Analytical boron diffusivity model in silicon for thermal diffusion from boron silicate glass film

    Science.gov (United States)

    Kurachi, Ikuo; Yoshioka, Kentaro

    2015-09-01

    An analytical boron diffusivity model in silicon for thermal diffusion from a boron silicate glass (BSG) film has been proposed in terms of enhanced diffusion due to boron-silicon interstitial pair formation. The silicon interstitial generation is considered to be a result of the silicon kick-out mechanism by the diffused boron at the surface. The additional silicon interstitial generation in the bulk silicon is considered to be the dissociation of the diffused pairs. The former one causes the surface boron concentration dependent diffusion. The latter one causes the local boron concentration dependent diffusion. The calculated boron profiles based on the diffusivity model are confirmed to agree with the actual diffusion profiles measured by secondary ion mass spectroscopy (SIMS) for a wide range of the BSG boron concentration. This analytical diffusivity model is a helpful tool for p+ boron diffusion process optimization of n-type solar cell manufacturing.

  8. Synthesis and biological evaluation of boronated polyglycerol dendrimers as potential agent for neutron capture therapy

    International Nuclear Information System (INIS)

    Silva, Gerald S.; Camillo, Maria A.P.; Higa, Olga Z.; Pugliesi, Reynaldo; Fermamdes, Edson G.R.; Queiroz, Alvaro A.A. de

    2005-01-01

    In this work, the polyglycerol dendrimer (PGLD) generation 5 was used to obtain a boronated macromolecule for boron neutron capture therapy. The PGLD dendrimer was synthesized by the ring opening polymerization of deprotonated glycidol using polyglycerol as core functionality in a step-growth processes denominated divergent synthesis. The PGLD dendritic structure was confirmed by gel permeation chromatography, nuclear magnetic resonance ( 1 H-NMR, 13 C-NMR) and matrix assisted laser desorption/ionization techniques. The synthesized dendrimer presented low dispersion in molecular weights (M w /M n = 1.05) and a degree of branching of 0.82, which characterize the polymer dendritic structure. Quantitative neutron capture radiography was used to investigate the boron-10 enrichment of the polyglycerol dendrimer. The in vitro cytotoxicity to Chinese hamster ovary cells of 10 B-PGLD dendrimer indicate lower cytotoxicity, suggesting that the macromolecule is a biocompatible material. (author)

  9. Safety aspects in a chemical exchange process plant

    International Nuclear Information System (INIS)

    Sharma, B.K.

    2016-01-01

    Based on a chemical exchange process involving solid liquid exchange, studies have been undertaken to enrich 10 B isotope of boron using ion exchange chromatography in which a strong base anion exchange resin in hydroxyl form is equilibrated with boric acid solution in presence of mannitol (a complexing reagent to boric acid) to enhance the acidity and hence the isotopic exchange separation factor for 10 B = 11 B exchange reaction. Using the electrochemical techniques such as pH-metry and conductimetry, the choice of a suitable complexing reagent was made amongst ethylene glycol, propylene glycol, dextrose and mannitol for cost-effective separation of isotopes of boron and monitoring of band movements using these electrochemical techniques. The optimum conditions for the regeneration of strong base anion exchange resins of type-I and type-II were determined for cost-effective separation of isotopes of boron by ion exchange chromatography. The possibility of using unspent alkali content of the effluent was also exploited. Removal of carbonate impurity from Rayon grade caustic lye (used as regenerant after dilution) and recycling of Ba(OH) 2 was studied to avoid waste disposal problems. This process is an industrially viable process. The various safety aspects followed during operation of this plant are described in this paper. (author)

  10. An overview of male reproductive studies of boron with an emphasis on studies of highly exposed Chinese workers

    DEFF Research Database (Denmark)

    Scialli, Anthony R; Bonde, Jens Peter; Brüske-Hohlfeld, Irene

    2010-01-01

    Boron treatment of rats, mice, and dogs has been associated with testicular toxicity, characterized by inhibited spermiation at lower dose levels and a reduction in epididymal sperm count at higher dose levels. The no-adverse-effect level for reproductive effects in male rats is 17.5mg B/kg bw...... in the same community and in a remote community were used as controls. Boron workers (n=75) had a mean daily boron intake of 31.3mg B/day, and a subset of 16 of these men, employed at a plant where there was heavy boron contamination of the water supply, had an estimated mean daily boron intake of 125 mg B...

  11. Phytoalexin-enriched functional foods.

    Science.gov (United States)

    Boue, Stephen M; Cleveland, Thomas E; Carter-Wientjes, Carol; Shih, Betty Y; Bhatnagar, Deepak; McLachlan, John M; Burow, Matthew E

    2009-04-08

    Functional foods have been a developing area of food science research for the past decade. Many foods are derived from plants that naturally contain compounds beneficial to human health and can often prevent certain diseases. Plants containing phytochemicals with potent anticancer and antioxidant activities have spurred development of many new functional foods. This has led to the creation of functional foods to target health problems such as obesity and inflammation. More recent research into the use of plant phytoalexins as nutritional components has opened up a new area of food science. Phytoalexins are produced by plants in response to stress, fungal attack, or elicitor treatment and are often antifungal or antibacterial compounds. Although phytoalexins have been investigated for their possible role in plant defense, until recently they have gone unexplored as nutritional components in human foods. These underutilized plant compounds may possess key beneficial properties including antioxidant activity, anti-inflammation activity, cholesterol-lowering ability, and even anticancer activity. For these reasons, phytoalexin-enriched foods would be classified as functional foods. These phytoalexin-enriched functional foods would benefit the consumer by providing "health-enhanced" food choices and would also benefit many underutilized crops that may produce phytoalexins that may not have been considered to be beneficial health-promoting foods.

  12. Advanced microstructure of boron carbide.

    Science.gov (United States)

    Werheit, Helmut; Shalamberidze, Sulkhan

    2012-09-26

    The rhombohedral elementary cell of the complex boron carbide structure is composed of B(12) or B(11)C icosahedra and CBC, CBB or B□B (□, vacancy) linear arrangements, whose shares vary depending on the actual chemical compound. The evaluation of the IR phonon spectra of isotopically pure boron carbide yields the quantitative concentrations of these components within the homogeneity range. The structure formula of B(4.3)C at the carbon-rich limit of the homogeneity range is (B(11)C) (CBC)(0.91) (B□B)(0.09) (□, vacancy); and the actual structure formula of B(13)C(2) is (B(12))(0.5)(B(11)C)(0.5)(CBC)(0.65)(CBB)(0.16) (B□B)(0.19), and deviates fundamentally from (B(12))CBC, predicted by theory to be the energetically most favourable structure of boron carbide. In reality, it is the most distorted structure in the homogeneity range. The spectra of (nat)B(x)C make it evident that boron isotopes are not randomly distributed in the structure. However, doping with 2% silicon brings about a random distribution.

  13. Boron isotopes in geothermal systems

    International Nuclear Information System (INIS)

    Aggarwal, J.

    1997-01-01

    Boron is a highly mobile element and during water-rock reactions, boron is leached out of rocks with no apparent fractionation. In geothermal systems where the water recharging the systems are meteoric in origin, the B isotope ratio of the geothermal fluid reflects the B isotope ratio of the rocks. Seawater has a distinctive B isotope ratio and where seawater recharges the geothermal system, the B isotope ratio of the geothermal system reflects the mixing of rock derived B and seawater derived B. Any deviations of the actual B isotope ratio of a mixture reflects subtle differences in the water-rock ratios in the cold downwelling limb of the hydrothermal system. This paper will present data from a variety of different geothermal systems, including New Zealand; Iceland; Yellowston, USA; Ibusuki, Japan to show the range in B isotope ratios in active geothermal systems. Some of these systems show well defined mixing trends between seawater and the host rocks, whilst others show the boron isotope ratios of the host rock only. In geothermal systems containing high amounts of CO 2 boron isotope ratios from a volatile B source can also be inferred. (auth)

  14. Structural characterization of electrodeposited boron

    Indian Academy of Sciences (India)

    electrolysis was crystalline in nature, X-ray diffraction pat-. ∗. Author for correspondence (sas@igcar.gov.in) .... Elemental boron was synthesized by the electrolysis of molten potassium fluroborate dissolved in a ... A high-throughput Renishaw micro-Raman spectrome- ter (model Invia) was employed to record Raman ...

  15. Preparation process of boron nitride

    International Nuclear Information System (INIS)

    Mignani, G.; Ardaud, P.

    1990-01-01

    High purity boron nitride, without Si and a low carbon content, is prepared by pyrolysis, under an ammoniac atmosphere, of the reaction product between a B-trihalogenoborazole and a primary amine RNH 2 when R is a hydrocarbon radical eventually substituted containing from 1 to 6 carbon atoms inclusively [fr

  16. Structural characterization of electrodeposited boron

    Indian Academy of Sciences (India)

    Structural characterization of electrodeposited boron was carried out by using transmission electron microscopy and Raman spectroscopy. Electron diffraction and phase contrast imaging were carried out by using transmission electron microscopy. Phase identification was done based on the analysis of electron diffraction ...

  17. Prevention of uncontrolled boron dilution

    International Nuclear Information System (INIS)

    Sere, J. L.

    1997-01-01

    The paper presents a synthesis of the global analysis of uncontrolled boron dilution risk performed by (European Consortium Mochovce (EUCOM) in the frame of Safety Measures RC 01 and AA 11. Recommendation for additional improvements (mainly I and C interlocks or inhibition) are presented. (author)

  18. Boron-11 MRI and MRS of intact animals infused with a boron neutron capture agent

    International Nuclear Information System (INIS)

    Kabalka, G.W.; Davis, M.; Bendel, P.

    1988-01-01

    Boron neutron capture therapy (BNCT) depends on the delivery of boron-containing drugs to a targeted lesion. Currently, the verification and quantification of in vivo boron content is a difficult problem. Boron-11 spectroscopy was utilized to confirm the presence of a dimeric sulfhydryl dodecaborane BNCT agent contained in an intact animal. Spectroscopy experiments revealed that the decay time of transverse magnetization of the boron-11 spins was less than 1 ms which precluded the use of a 2DFT imaging protocol. A back-projection protocol was developed and utilized to generate the first boron-11 image of a BNCT agent in the liver of an intact Fisher 344 rat

  19. Preparation, Characterization and Adsorption Study of Granular Activated Carbon/Iron oxide composite for the Removal of Boron and Organics from Wastewater

    Directory of Open Access Journals (Sweden)

    Affam Augustine Chioma

    2018-01-01

    Full Text Available Boron and organics maybe in high concentration during production of oil and gas, fertilizers, glass, and detergents. In addition, boron added to these industrial processes may require to be removed by the wastewater treatment plant. The preparation, characterization and application of iron oxide-activated carbon composite for removal of boron and COD was studied. The one variable at a time (OVAT method was implemented to obtain desirable operating conditions (adsorbent dosage 5 g/L, reaction time 2 h, agitation speed 100 rpm, pH 5 for COD removal and pH 9 for boron removal. It was found that boron and organics present in a sample wastewater may require to be treated separately to remove the contaminants. The study achieved 97 and 70% for boron and COD removal, respectively. Adsorption as an alternative cheap source of treatment and its practicability for small communities is recommended as effective in removal of contaminants from river water.

  20. Preparation, Characterization and Adsorption Study of Granular Activated Carbon/Iron oxide composite for the Removal of Boron and Organics from Wastewater

    Science.gov (United States)

    Chioma Affam, Augustine; Chung Wong, Chee; Seyam, Mohammed A. B.; Matt, Chelsea Ann Anak Frederick; Lantan Anak Sumbai, Josephine; Evuti, Abdullahi Mohammed

    2018-03-01

    Boron and organics maybe in high concentration during production of oil and gas, fertilizers, glass, and detergents. In addition, boron added to these industrial processes may require to be removed by the wastewater treatment plant. The preparation, characterization and application of iron oxide-activated carbon composite for removal of boron and COD was studied. The one variable at a time (OVAT) method was implemented to obtain desirable operating conditions (adsorbent dosage 5 g/L, reaction time 2 h, agitation speed 100 rpm, pH 5 for COD removal and pH 9 for boron removal). It was found that boron and organics present in a sample wastewater may require to be treated separately to remove the contaminants. The study achieved 97 and 70% for boron and COD removal, respectively. Adsorption as an alternative cheap source of treatment and its practicability for small communities is recommended as effective in removal of contaminants from river water.

  1. Boron filled siloxane polymers for radiation shielding

    Science.gov (United States)

    Labouriau, Andrea; Robison, Tom; Shonrock, Clinton; Simmonds, Steve; Cox, Brad; Pacheco, Adam; Cady, Carl

    2018-03-01

    The purpose of the present work was to evaluate changes to structure-property relationships of 10B filled siloxane-based polymers when exposed to nuclear reactor radiation. Highly filled polysiloxanes were synthesized with the intent of fabricating materials that could shield high neutron fluences. The newly formulated materials consisted of cross-linked poly-diphenyl-methylsiloxane filled with natural boron and carbon nanofibers. This polymer was chosen because of its good thermal and chemical stabilities, as well as resistance to ionizing radiation thanks to the presence of aromatic groups in the siloxane backbone. Highly isotopically enriched 10B filler was used to provide an efficient neutron radiation shield, and carbon nanofibers were added to improve mechanical strength. This novel polymeric material was exposed in the Annular Core Research Reactor (ACRR) at Sandia National Labs to five different neutron/gamma fluxes consisting of very high neutron fluences within very short time periods. Thermocouples placed on the specimens recorded in-situ temperature changes during radiation exposure, which agreed well with those obtained from our MCNP simulations. Changes in the microstructural, thermal, chemical, and mechanical properties were evaluated by SEM, DSC, TGA, FT-IR NMR, solvent swelling, and uniaxial compressive load measurements. Our results demonstrate that these newly formulated materials are well-suitable to be used in applications that require exposure to different types of ionizing conditions that take place simultaneously.

  2. New cathode design boron lined proportional counters for neutron area monitoring application

    International Nuclear Information System (INIS)

    Dighe, Priyamvada M.

    2007-01-01

    A new cathode design boron lined proportional counter of 26mm IDx100mm sensitive length SS304 cathode has been developed with boron-coated baffles separated by 3mm spacers inserted in the sensitive volume perpendicular to the axis. The baffles and the spacers were coated with indigenously available 27.7% enriched 10 B. The introduction of baffles enhanced the boron coated surface area by a factor of 2.8. Tests in 120nv thermal neutron flux show that the counter has 0.84cps/nv thermal neutron sensitivity, which shows enhancement in the sensitivity by a factor of 2.78 due to baffle structure. For comparison standard cylindrical cathode geometry counter coated with 92% enriched 10 B on its inner wall with a coating thickness of 0.8mg/cm 2 is developed with same outer dimensions for neutron area monitoring applications. The counter has 1cps/nv thermal neutron sensitivity. Comparative tests carried out on counters with and without baffle structure show that the baffles enhance the neutron sensitivity and in 2kR/h gamma background the effect of gamma pile up is similar on both the counters. The variation in cathode internal diameter due to baffle structure gives higher voltage plateau slope (2.8%/10V) as compared to conventional cylindrical geometry counter (1.2%/10V). The usability of boron lined counters for neutron area monitoring applications for the cylindrical geometry counter has been studied

  3. Effects of boron-water on cattle

    Energy Technology Data Exchange (ETDEWEB)

    Green, G.H.; Weeth, H.J.

    1975-01-01

    To determine the effects of subtoxic concentrations of boron in drinking water, 12 Hereford heifers were used in a 3 x 3 latin-square experiment with four squares. Treatments were tap-water (0.8 ppm boron), 150 ppm boron-water, and 300 ppm boron-water. Periods were 30 days each. Total urine was collected during the last week of each period, and renal clearance observations (based on creatinine) were made on the last day of each period. While water consumption and total urine weight were not affected by the boron treatments, hay consumption decreased, and weight loss was noted. Plasma boron concentrations were 0.53 +/- 0.151 ppm, 11.2 +/- 0.91 ppm, and 18.9 +/- 0.60 ppm while the heifers were drinking tap-water, 150 ppm boron-water, and 300 ppm boron-water respectively. Urinary boron excretion rates were tap water, 64 +/- 5.6 mg/day; 150 ppm, 2841 +/- 181.2 mg/day; 300 ppm, 4932 +/- 173.3 mg/day. Although glomerular filtration and osmolal clearance were unaffected by the boron-waters, a relative diuresis was indicated by the free water clearance effects. The percent of filtered boron which was reabsorbed decreased with increased exogenous boron, as well as both plasma and urinary phosphate. These data indicate that 300 ppm boron is not acutely toxic to heifers when consumed via the drinking water. The safe tolerance concentration, however, must lie below 150 ppm because this concentration was responsible for some deleterious effects.

  4. Interferência da disponibilidade de luz na resposta à adubação de plantios de enriquecimento com leguminosas arbóreas Interference of light availability on response to fertilization of enrichment plantings with leguminous trees

    Directory of Open Access Journals (Sweden)

    Marco Aurélio de Carvalho Silva

    2013-03-01

    Full Text Available O objetivo deste trabalho foi avaliar a interferência da disponibilidade de luz na resposta à adubação de plantios de enriquecimento da capoeira com leguminosas arbóreas. As espécies Hymenaea courbaril, Stryphnodendron guianense, Parkia platycephala e Stryphnodendron microstachyum foram plantadas em capoeira, sob três tratamentos de fertilização: adubação orgânica, adubação orgânica acrescida de mineral e ausência de adubação. A disponibilidade de luz condicionou a resposta de P. platycephala e H. courbaril à fertilização. A aleatorização não foi suficiente para garantir condições semelhantes de luz nos plantios de enriquecimento. A variação na quantidade de luz incidente no sub‑bosque compromete a correta avaliação dos tratamentos de fertilização.The objective of this work was to evaluate the interference of light availability on response to fertilization of enrichment plantings of secondary growth forest with leguminous trees. The species Hymenaea courbaril, Stryphnodendron guianense, Parkia platycephala, and Stryphnodendron microstachyum were planted in a secondary growth forest under three fertilization treatments: organic fertilization, organic fertilization plus mineral fertilization, and absence of fertilization. Light availability modulated the response of P. platycephala and H. courbaril to fertilization treatments. Randomization was not sufficient to ensure similar light conditions in the enrichment plantings. Variation in the amount of incident light compromises the sound evaluation of fertilization treatments.

  5. WEED CONTROL AND BORON NUTRITION ON Eucalyptus IN SILVOPASTORAL SYSTEM

    Directory of Open Access Journals (Sweden)

    Alexandre Magno Brighenti

    2015-04-01

    Full Text Available The objective of this study was to evaluate the control of weeds in the rows of eucalyptus (Eucalyptus urograndis with herbicides applied singly or combined with boron (B, as well as, the response of Eucalyptus plants to this micronutrient. The experiments were carried out in a split-plot with randomized complete block design, with three replicates. Six treatments were applied to the plots: (i weeded control, (ii control without weeding, (iii glyphosate (1080 g ae ha-1 + chlorimuron-ethyl (10 g ai ha-1 + 0.05% v / v mineral oil, (iv glyphosate (1080 g ae  ha-1 + isoxaflutole (112.5 g ai ha-1,  (v glyphosate (1080 g ae ha-1 and  (vi oxyfluorfen (480 g ai ha-1. The sub-plots consisted of the absence or presence of 4 kg of boric acid (H3BO3 - 17% B in 100 L of water. The addition of boric acid in the solution containing the herbicides did not affect the weed control. There was an increase in boron content in the soil and consequently an increase in the boron levels in the eucalyptus leaves. The combined application of herbicides plus boric acid is perfectly suitable for preventing dry of the pointer on eucalyptus plants. Keywords: Eucalyptus urograndis; chemical control; herbicides; micronutrients; Urochloa decumbens.

  6. Effect of boron application time on yield of wheat, rice and cotton crop in Pakistan

    OpenAIRE

    Riaz Ahmad* and Muhammad Irshad

    2011-01-01

    Boron (B), one of the essential micronutrients, plays vital role in plant growth. Thirty one field experimentswere conducted to evaluate the response of wheat, rice and cotton to B application throughout Pakistan during2005-08. Boron was applied at 1 kg ha-1 as Borax decahydrate (11.3% B) at different times along withrecommended doses of N, P and K. The results revealed that B application at sowing time to wheat increasedsignificantly the number of tillers plant-1 (15%), number of grains spik...

  7. Between-species differences in gene copy number are enriched among functions critical for adaptive evolution in Arabidopsis halleri.

    Science.gov (United States)

    Suryawanshi, Vasantika; Talke, Ina N; Weber, Michael; Eils, Roland; Brors, Benedikt; Clemens, Stephan; Krämer, Ute

    2016-12-22

    Gene copy number divergence between species is a form of genetic polymorphism that contributes significantly to both genome size and phenotypic variation. In plants, copy number expansions of single genes were implicated in cultivar- or species-specific tolerance of high levels of soil boron, aluminium or calamine-type heavy metals, respectively. Arabidopsis halleri is a zinc- and cadmium-hyperaccumulating extremophile species capable of growing on heavy-metal contaminated, toxic soils. In contrast, its non-accumulating sister species A. lyrata and the closely related reference model species A. thaliana exhibit merely basal metal tolerance. For a genome-wide assessment of the role of copy number divergence (CND) in lineage-specific environmental adaptation, we conducted cross-species array comparative genome hybridizations of three plant species and developed a global signal scaling procedure to adjust for sequence divergence. In A. halleri, transition metal homeostasis functions are enriched twofold among the genes detected as copy number expanded. Moreover, biotic stress functions including mostly disease Resistance (R) gene-related genes are enriched twofold among genes detected as copy number reduced, when compared to the abundance of these functions among all genes. Our results provide genome-wide support for a link between evolutionary adaptation and CND in A. halleri as shown previously for Heavy metal ATPase4. Moreover our results support the hypothesis that elemental defences, which result from the hyperaccumulation of toxic metals, allow the reduction of classical defences against biotic stress as a trade-off.

  8. Re-sintered boron-rich polycrystalline cubic boron nitride and method for making same

    Energy Technology Data Exchange (ETDEWEB)

    Lavens, T.R.; Corrigan, F.R.; Shott, R.L.; Bovenkerk, H.P.

    1987-06-16

    A method is described for making re-sintered polycrystalline cubic boron nitride (CBN) which comprises: (a) placing sintered substantially catalyst-free boron-rich polycrystalline cubic boron nitride particles in a high pressure/high temperature apparatus, the particles being substantially free of sintering inhibiting impurities; (b) subjecting the boron-rich cubic boron nitride particles to a pressure and a temperature adequate to re-sinter the particles, the temperature being below the CBN reconversion temperature; (c) maintaining the temperature and pressure for a time sufficient to re-sinter the boron-rich cubic boron nitride particles in the apparatus, and (d) recovering the re-sintered polycrystalline cubic boron nitride from the apparatus.

  9. The production, characterization, and neutronic performance of boron nitride coated uranium dioxide fuel

    International Nuclear Information System (INIS)

    Uslu, I.; Colak, U.; Tombakoglu, M.; Gunduz, G.

    1995-01-01

    The fuel pellets produced by sol-gel technique were coated with boron nitride (BN). This was achieved through chemical vapor deposition (CVD) using boron trichloride and ammonia. Mixing and chemical reaction take place at a temperature around 875 K. The coated samples were then sintered at 1600 K. Thermal reactor physics lattice-cell code WIMS-D/4 was used in the neutronic analysis of CANDU fuel bundle to observe the neutronic performance of the coated fuel. Three types of fuel were considered; fuel made of natural uranium, slightly enriched uranium (SEU, enrichment: 0.82 % U-235), and SEU with various BN coatings. The burnup calculations showed that feasible coating thickness is between 1 to 2 μm. (author)

  10. Boron Stress Responsive MicroRNAs and Their Targets in Barley

    Science.gov (United States)

    Ozhuner, Esma; Eldem, Vahap; Ipek, Arif; Okay, Sezer; Sakcali, Serdal; Zhang, Baohong; Boke, Hatice; Unver, Turgay

    2013-01-01

    Boron stress is an environmental factor affecting plant development and production. Recently, microRNAs (miRNAs) have been found to be involved in several plant processes such as growth regulation and stress responses. In this study, miRNAs associated with boron stress were identified and characterized in barley. miRNA profiles were also comparatively analyzed between root and leave samples. A total of 31 known and 3 new miRNAs were identified in barley; 25 of them were found to respond to boron treatment. Several miRNAs were expressed in a tissue specific manner; for example, miR156d, miR171a, miR397, and miR444a were only detected in leaves. Additionally, a total of 934 barley transcripts were found to be specifically targeted and degraded by miRNAs. In silico analysis of miRNA target genes demonstrated that many miRNA targets are conserved transcription factors such as Squamosa promoter-binding protein, Auxin response factor (ARF), and the MYB transcription factor family. A majority of these targets were responsible for plant growth and response to environmental changes. We also propose that some of the miRNAs in barley such as miRNA408 might play critical roles against boron exposure. In conclusion, barley may use several pathways and cellular processes targeted by miRNAs to cope with boron stress. PMID:23555702

  11. The effects of boron on improving aluminium tolerance in coriander (Coriandrum sativum L.

    Directory of Open Access Journals (Sweden)

    Zahra Rezaei

    2015-03-01

    Full Text Available In this study, the role of boron (BO33- on improving tolerance of coriander plant (Coriandrum sativum L. subjected to different concentrations of aluminum (Al3+ was evaluated. In this regard, an experiment was implemented with seven different concentrations of aluminum including: 0.25, 0.50, 1.00, 2.00, 3.00 and 4.00 mg/L Al3+ and three concentrations of boron including: 0.25, 0.5 and 0.75 mg/L BO33- with the control treatment. The experiment was concluded based on completely randomized design with three replications. Seeds of coriander were germinated in germinator and seedlings were grown in Hogland´s solution with different boron and aluminium concentrations. Results showed that different levels of Al3+, decreased dry weight, leaf area, length of shoot and root, amount of chlorophyll and aluminium, while proline concentration and Al3+accumulation increased. Nearly, in all concentrations of Al3+, plant height, dry weight and chlorophyll content promoted with increasing boron concentrations, but proline concentration was decreased. It could be concluded that application of boron along with Al3+, might have proved plant growth and neutralized effects of Al toxicity.

  12. Uranium enrichment plans

    International Nuclear Information System (INIS)

    Thomas, D.C.; Gagne, R.W.

    1978-01-01

    The following topics are covered: the status of the Government's existing uranium enrichment services contracts, natural uranium requirements based on the latest contract information, uncertainty in predicting natural uranium requirements based on uranium enrichment contracts, and domestic and foreign demand assumed in enrichment planning

  13. Contamination of the ground waters and surface waters by boron in Lerma Valley, NW-Argentina - an inventory

    International Nuclear Information System (INIS)

    Bundschuh, J.

    1992-01-01

    Ground- and surface waters in areas unaffected by pollution from borax and boric acid producing plants exhibit low boron concentrations of less than 300 μg B/l. Only at the boric acid plant 'Mineratea' is the groundwater contaminated, with up to 6200 μg B/l occurring within an area of 8 to 10 km 2 with more than 1000 μg boron/l. Even higher boron concentrations (up to 18 μg B/l) are present in polluted surface waters. Not the boron concentration in the irrigation water, but the absolute amount of boron added to the plants by irrigation is what determines plant toxicity. For the contaminated area of the boric acid 'Mineratea', characterized by boron concentrations of between 1000 and 6000 μg B/l, the maximal amounts of irrigation water that can be applied lies between 300 and 8 mm. In order to protect the local groundwater resoures from present and future contamination, environmental impact assessment on industrial projects in the area are required. In this way, the quality of the drinking and irrigation water can be guaranteed through suitable measures, without hindering further necessary industrial development of the region. (orig./UWA) [de

  14. Design and fabrication of an innovative and environmental friendly adsorbent for boron removal.

    Science.gov (United States)

    Wei, Yu-Ting; Zheng, Yu-Ming; Chen, J Paul

    2011-03-01

    Boron can pose adverse effects on human beings and plants species. It exists in various water environments and is difficult to be removed by conventional technologies. In this study, an efficient and environmental friendly sorbent was fabricated by the functionalization of a natural biopolymer, chitosan, with N-methylglucamine through atom transfer radical polymerization. The SEM and BET studies revealed that the sorbent had a rougher surface and a more porous structure than the chitosan. At the optimum neutral pH, the maximum sorption capacity was as high as 3.25 mmol/g, much higher than the commercial boron selective resins (e.g., Amberlite IRA-743) and many other synthesized sorbents. Almost 90% of boron sorption occurred within 8 h and the equilibrium was established in 12 h, which was well described by an intraparticle surface diffusion model. The presence of sodium chloride and sodium nitrate had no effect on the boron removal. The boron concentration in seawater could be reduced to less than 0.5 mg/L from 4.8 mg/L when a sorbent dosage of 1.2 g/L was used. It was therefore concluded that the sorption technology from this study could be promising for boron removal from aqueous solutions. Copyright © 2011 Elsevier Ltd. All rights reserved.

  15. Helium behaviour in implanted boron carbide

    Directory of Open Access Journals (Sweden)

    Motte Vianney

    2015-01-01

    Full Text Available When boron carbide is used as a neutron absorber in nuclear power plants, large quantities of helium are produced. To simulate the gas behaviour, helium implantations were carried out in boron carbide. The samples were then annealed up to 1500 °C in order to observe the influence of temperature and duration of annealing. The determination of the helium diffusion coefficient was carried out using the 3He(d,p4He nuclear reaction (NRA method. From the evolution of the width of implanted 3He helium profiles (fluence 1 × 1015/cm2, 3 MeV corresponding to a maximum helium concentration of about 1020/cm3 as a function of annealing temperatures, an Arrhenius diagram was plotted and an apparent diffusion coefficient was deduced (Ea = 0.52 ± 0.11 eV/atom. The dynamic of helium clusters was observed by transmission electron microscopy (TEM of samples implanted with 1.5 × 1016/cm2, 2.8 to 3 MeV 4He ions, leading to an implanted slab about 1 μm wide with a maximum helium concentration of about 1021/cm3. After annealing at 900 °C and 1100 °C, small (5–20 nm flat oriented bubbles appeared in the grain, then at the grain boundaries. At 1500 °C, due to long-range diffusion, intra-granular bubbles were no longer observed; helium segregates at the grain boundaries, either as bubbles or inducing grain boundaries opening.

  16. Methods for separating boron from borated paraffin wax and its determination by ion chromatography

    International Nuclear Information System (INIS)

    Jeyakumar, S.

    2015-01-01

    Boron compounds are found to be useful in shielding against high-energy neutrons. In radiotherapy treatments, in order to protect occupational workers and patients from the undesirable neutron and gamma doses, paraffin wax containing B 4 C/boric acid is used. Low-level borate wastes generated from the nuclear power plants have been immobilized with paraffin wax using a concentrate waste drying system (CWDS). Borated paraffin waxes are prepared by mixing calculated amounts of either boric acid or boron carbide with the molten wax. This necessitates the determination of boron at different locations in order to check the homogeneous distribution of B over the borated wax. The determination of boron in nuclear materials is inevitable due to its high neutron absorption cross section. For the determination of boron in borated waxes, not many methods have been reported. A method based on the pyrohydrolysis extraction of boron and its quantification with ion chromatography was proposed for paraffin waxes borated with H 3 BO 3 and B 4 C. The B 4 C optimum pyrohydrolysis conditions were identified. Wax samples were mixed with U 3 O 8 , which prevents the sample from flare up, and also accelerates the extraction of boron. Pyrohydrolysis was carried out with moist O 2 at 950℃ for 60 and 90 min for wax with H 3 BO 3 and wax with B 4 C, respectively. Two simple methods of separation based on alkali extraction and melting wax in alkali were also developed exclusively for wax with H 3 BO 3 . In all the separations, the recovery of B was above 98%. During IC separation, B was separated as boron-mannitol anion complex. Linear calibration was obtained between 0.1 and 50 ppm of B, and LOD was calculated as 5 ppb (S/N=3). The reproducibility was better than 5% (RSD)

  17. Boron clusters in luminescent materials.

    Science.gov (United States)

    Mukherjee, Sanjoy; Thilagar, Pakkirisamy

    2016-01-21

    In recent times, luminescent materials with tunable emission properties have found applications in almost all aspects of modern material sciences. Any discussion on the recent developments in luminescent materials would be incomplete if one does not account for the versatile photophysical features of boron containing compounds. Apart from triarylboranes and tetra-coordinate borate dyes, luminescent materials consisting of boron clusters have also found immense interest in recent times. Recent studies have unveiled the opportunities hidden within boranes, carboranes and metalloboranes, etc. as active constituents of luminescent materials. From simple illustrations of luminescence, to advanced applications in LASERs, OLEDs and bioimaging, etc., the unique features of such compounds and their promising versatility have already been established. In this review, recent revelations about the excellent photophysical properties of such materials are discussed.

  18. Boron-10 ABUNCL Active Testing

    Energy Technology Data Exchange (ETDEWEB)

    Kouzes, Richard T.; Ely, James H.; Lintereur, Azaree T.; Siciliano, Edward R.

    2013-07-09

    The Department of Energy Office of Nuclear Safeguards and Security (NA-241) is supporting the project Coincidence Counting With Boron-Based Alternative Neutron Detection Technology at Pacific Northwest National Laboratory (PNNL) for the development of a 3He proportional counter alternative neutron coincidence counter. The goal of this project is to design, build and demonstrate a system based upon 10B-lined proportional tubes in a configuration typical for 3He-based coincidence counter applications. This report provides results from testing of the active mode of the General Electric Reuter-Stokes Alternative Boron-Based Uranium Neutron Coincidence Collar (ABUNCL) at Los Alamos National Laboratory using sources and fuel pins.

  19. Uranium Enrichment, an overview

    International Nuclear Information System (INIS)

    Coates, J.H.

    1994-01-01

    This general presentation on uranium enrichment will be followed by lectures on more specific topics including descriptions of enrichment processes and assessments of the prevailing commercial and industrial situations. I shall therefore avoid as much as possible duplications with these other lectures, and rather dwell on: some theoretical aspects of enrichment in general, underlying the differences between statistical and selective processes, a review and comparison between enrichment processes, remarks of general order regarding applications, the proliferation potential of enrichment. It is noteworthy that enrichment: may occur twice in the LWR fuel cycle: first by enriching natural uranium, second by reenriching uranium recovered from reprocessing, must meet LWR requirements, and in particular higher assays required by high burn up fuel elements, bears on the structure of the entire front part of the fuel cycle, namely in the conversion/reconversion steps only involving UF 6 for the moment. (author). tabs., figs., 4 refs

  20. Boron removal from geothermal waters by electrocoagulation.

    Science.gov (United States)

    Yilmaz, A Erdem; Boncukcuoğlu, Recep; Kocakerim, M Muhtar; Yilmaz, M Tolga; Paluluoğlu, Cihan

    2008-05-01

    Most of the geothermal waters in Turkey contain extremely high concentration of boron when they are used for irrigation. The use of geothermal waters for irrigation can results in excess amount deposition of boron in soil. On the other hand, a minimal boron concentration is required for irrigational waters. In this study, electrocoagulation (EC) was selected as a treatment process for the removal of boron from thermal waters obtained from Ilica-Erzurum in Turkey. Current density (CD), pH of solution and temperature of solution were selected as operational parameters. The results showed that boron removal efficiency increased from pH 4.0 to 8.0 and decreased at pH 10.0. Although boron removal efficiency was highest at pH 8.0, energy consumption was very high at this pH value compared to other pH intervals. Boron removal efficiency reached to 95% with increasing current density from 1.5 to 6.0 mA/cm(2), but energy consumption was also increased in this interval. At higher temperatures of solution, such as 313 and 333 K, boron removal efficiency increased. At optimum conditions, boron removal efficiency in geothermal water reached up to 95%.

  1. Removal of boron (B) from waste liquors.

    Science.gov (United States)

    Jiang, J Q; Xu, Y; Simon, J; Quill, K; Shettle, K

    2006-01-01

    This paper explores the use of electrocoagulation to remove boron from waste effluent in comparison with alum coagulation. In treating model test wastes, greater boron removals were achieved with electrocoagulation at low doses than conventional alum coagulation when reaction was undertaken for the same conditions (pH 8.5, and initial boron concentration was 500 mg/L). Al electrocoagulation can achieve good boron removal performance (68.3%) at a dose of 2.1 (as molar ratio of Al:B, and for current density of 62.1 A/m2), while alum coagulation can only achieve the maximum boron removal of 56% at a dose of 2.4. Also, Al electrocoagulation can remove 15-20% more boron than alum coagulation for the same dose compared in the treatment of both model test wastes and industry effluent. The estimation of running costs shows that to achieve 75% boron removal from industry waste effluent, i.e. removing 150 g of boron from 1 m3 of effluent, electrocoagulation was 6.2 times cheaper than alum coagulation. The economic advantage of electrocoagulation in the treatment of boron-containing waste effluent is thus significant.

  2. The boron geochemistry of siliceous sponges

    Science.gov (United States)

    de Leon, A.; Wille, M.; Eggins, S. M.; Ellwood, M. J.

    2009-12-01

    The boron content and isotopic composition (δ11B) of marine carbonate organisms can be linked to the pH of the seawater in which they have grown, making carbonates a useful tool for palaeo-seawater pH reconstruction. A study by Furst (1981) documented unusually high boron concentrations in siliceous sponge spicules, in range from hundreds to a thousand ppm. This observation and the potential for preferential incorporation of the tetrahedral borate species into biogenic silica raises the question as to whether the boron chemistry of biogenic silica might also be influenced by seawater pH. We have measured the boron concentration and isotopic composition of siliceous sponges from the Southern Ocean region, with a view to (1) confirming the observations of Furst (1981), (2) assessing the factors that control boron incorporation and isotopic compositions of sponge silica, and (3) investigating the potentially significant role of siliceous sponges in the marine boron cycle. The measured boron concentrations in a diverse range of both demosponge and hexactinellid sponges confirm the high boron concentrations previously reported. The boron isotope compositions of these sponges vary from around +2‰ to +25‰ and greatly exceed the range in marine carbonates. This isotopic variation is inconsistent with seawater pH control but is correlated with ambient seawater silicon concentration, in a manner that suggests a link to silicon uptake kinetics and demand by sponges.

  3. Mineral resource of the month: boron

    Science.gov (United States)

    Crangle, Robert D.

    2012-01-01

    The article offers information on the mineral, boron. Boron compounds, particularly borates, have more commercial applications than its elemental relative which is a metalloid. Making up the 90% of the borates that are used worldwide are colemanite, kernite, tincal, and ulexite. The main borate deposits are located in the Mojave Desert of the U.S., the Tethyan belt in southern Asia, and the Andean belt of South America. Underground and surface mining are being used in gathering boron compounds. INSETS: Fun facts;Boron production and consumption.

  4. Conduction mechanism in boron carbide

    Science.gov (United States)

    Wood, C.; Emin, D.

    1984-01-01

    Electrical conductivity, Seebeck-coefficient, and Hall-effect measurements have been made on single-phase boron carbides, B(1-x)C(x), in the compositional range from 0.1 to 0.2 X, and between room temperature and 1273 K. The results indicate that the predominant conduction mechanism is small-polaron hopping between carbon atoms at geometrically inequivalent sites.

  5. Principles and techniques of uranium enrichment

    International Nuclear Information System (INIS)

    Frejacques, Claude; Mezin, Michel

    1975-01-01

    The main separation processes already used industrially or likely to be used before the end of century (gas diffusion, ultracentrifugation, laser, the nozzle process, a process developed in South Africa) are presented. Some data on the costs of the enrichment are clarified. The main characteristics of the enrichment market in which the Eurodif plant is called upon, on the expiration of five years, to take a foremost place are reported [fr

  6. Profile of World Uranium Enrichment Programs - 2007

    Energy Technology Data Exchange (ETDEWEB)

    Laughter, Mark D [ORNL

    2007-11-01

    It is generally agreed that the most difficult step in building a nuclear weapon is acquiring weapons grade fissile material, either plutonium or highly enriched uranium (HEU). Plutonium is produced in a nuclear reactor, while HEU is produced using a uranium enrichment process. Enrichment is also an important step in the civil nuclear fuel cycle, in producing low enriched uranium (LEU) for use in fuel for nuclear reactors. However, the same equipment used to produce LEU for nuclear fuel can also be used to produce HEU for weapons. Safeguards at an enrichment plant are the array of assurances and verification techniques that ensure uranium is only enriched to LEU, no undeclared LEU is produced, and no uranium is enriched to HEU or secretly diverted. There are several techniques for enriching uranium. The two most prevalent are gaseous diffusion, which uses older technology and requires a lot of energy, and gas centrifuge separation, which uses more advanced technology and is more energy efficient. Gaseous diffusion plants (GDPs) provide about 40% of current world enrichment capacity, but are being phased out as newer gas centrifuge enrichment plants (GCEPs) are constructed. Estimates of current and future enrichment capacity are always approximate, due to the constant upgrades, expansions, and shutdowns occurring at enrichment plants, largely determined by economic interests. Currently, the world enrichment capacity is approximately 53 million kg-separative work units (SWU) per year, with 22 million in gaseous diffusion and 31 million in gas centrifuge plants. Another 23 million SWU/year of capacity are under construction or planned for the near future, almost entirely using gas centrifuge separation. Other less-efficient techniques have also been used in the past, including electromagnetic and aerodynamic separations, but these are considered obsolete, at least from a commercial perspective. Laser isotope separation shows promise as a possible enrichment technique

  7. Distribution of equilibrium burnup for an homogeneous core with fuel elements of slightly enriched uranium (0.85% U-235) at Atucha I nuclear power plant

    International Nuclear Information System (INIS)

    Sidelnik, J.I.; Perez, R.A.; Salom, G.F.

    1987-01-01

    At Atucha I, the present fuel management with natural uranium comprises three burnup areas and one irradiation path, sometimes performing four steps in the reactor core, according to the requirements. The discharge burnup is 6.0 Mw d/kg U for a waste reactivity of 6.5 m k and a heavy water purity of 99.75%. This is a preliminary study to obtain the distribution of equilibrium burnup of an homogeneous core with slightly enriched uranium (0.85% by weight U-235), using the time-averaged method implemented in the code PUMA and a representative model of one third of core and fixed rod position. It was found a strategy of three areas and two paths that agrees with the present limits of channel power and specific power in fuel rod. The discharge burnup obtained is 11.6 Mw d/kg U. This strategy is calculated with the same method and a full core representation model is used to verify the obtained results. (Author)

  8. Boronline, a new generation of boron meter

    International Nuclear Information System (INIS)

    Pirat, P.

    2011-01-01

    Rolls-Royce is a global business providing integrated power systems for use on land, at sea and in the air. The Group has a balanced business portfolio with leading market positions - civil aerospace, defence aerospace, marine and energy Rolls-Royce understands the challenges of design, procurement, manufacture, operation and in-service support of nuclear reactor plants, with over 50 years of experience through the Royal Navy submarine programme. Rolls-Royce can therefore offer full product life-cycle management for new civil nuclear installations, as well as support to existing installations, including plant lifetime extensions. Rolls-Royce produced for 40 years, Instrumentation and Control (I and C) systems of and associated services for nuclear reactors in Europe, including 58 French reactors and others situated in the United States and in others countries, such as China. Rolls-Royce equipped in this domain 200 nuclear reactors in 20 countries. Among all of its nuclear systems, Rolls Royce is presenting to the conference its new generation of on-line boron measurement system, so called Boronline. (authors)

  9. [LOW-FAT, FERMENTED MILK ENRICHED WITH PLANT STEROLS, A STRATEGY TO REDUCE HYPERTRIGLYCERIDEMA IN CHILDREN, A DOUBLE-BLIND, RANDOMIZED PLACEBO-COTROLLED TRIAL].

    Science.gov (United States)

    Blumenfeld Olivares, Javier Andrés; San Mauro Martín, Ismael; Calle, Maria Elisa; Bischofberger Valdés, Cornelia; Perez Arruche, Eva; Arce Delgado, Esperanza; Ciudad, María Jose; Hernández Cabría, Marta; Collado Yurita, Luis

    2015-09-01

    in the last few years, as the rate of childhood obesity has been rising, there has been a parallel increase in the incidence of dislipemia in the pediatric population, in which blood triglycerids might play an important role. Plant sterols have been shown to be useful in the tratment of hypercholesterolemia, but not of hypertrygliceridemia. Our study focusses on determining the efficacy of phytosterol-supplemented milk for the treatment of hypertriglyceridemia in children. Study Population and Method: we designed a double- blind, randomized, controlled clinical trial on 67 pediatric patients. The treatment group received low-fat, phytosterol-supplemented milk and the control group received low-fat conventional milk. we observed differences in triglyceridemia between the phytosterol-supplemented group and the non-supplemented group. The effect attributable to the intake of milk supplemented with plant sterols was a reduction of triglyceridemia of 5.88 mg/dl compared with the control group. we conclude that phytosterol-supplemented milk (2.24 gr of plant sterols daily) might be an adequate tool in the management of hypertriglyceridemia in pediatric patients. Copyright AULA MEDICA EDICIONES 2014. Published by AULA MEDICA. All rights reserved.

  10. Spatial Burnout in Water Reactors with Nonuniform Startup Distributions of Uranium and Boron

    Science.gov (United States)

    Fox, Thomas A.; Bogart, Donald

    1955-01-01

    Spatial burnout calculations have been made of two types of water moderated cylindrical reactor using boron as a burnable poison to increase reactor life. Specific reactors studied were a version of the Submarine Advanced Reactor (sAR) and a supercritical water reactor (SCW) . Burnout characteristics such as reactivity excursion, neutron-flux and heat-generation distributions, and uranium and boron distributions have been determined for core lives corresponding to a burnup of approximately 7 kilograms of fully enriched uranium. All reactivity calculations have been based on the actual nonuniform distribution of absorbers existing during intervals of core life. Spatial burnout of uranium and boron and spatial build-up of fission products and equilibrium xenon have been- considered. Calculations were performed on the NACA nuclear reactor simulator using two-group diff'usion theory. The following reactor burnout characteristics have been demonstrated: 1. A significantly lower excursion in reactivity during core life may be obtained by nonuniform rather than uniform startup distribution of uranium. Results for SCW with uranium distributed to provide constant radial heat generation and a core life corresponding to a uranium burnup of 7 kilograms indicated a maximum excursion in reactivity of 2.5 percent. This compared to a maximum excursion of 4.2 percent obtained for the same core life when w'anium was uniformly distributed at startup. Boron was incorporated uniformly in these cores at startup. 2. It is possible to approach constant radial heat generation during the life of a cylindrical core by means of startup nonuniform radial and axial distributions of uranium and boron. Results for SCW with nonuniform radial distribution of uranium to provide constant radial heat generation at startup and with boron for longevity indicate relatively small departures from the initially constant radial heat generation distribution during core life. Results for SAR with a sinusoidal

  11. Partitioning CO2 effluxes from an Atlantic pine forest soil between endogenous soil organic matter and recently incorporated 13C-enriched plant material.

    Science.gov (United States)

    Fernandez, Irene; Cabaneiro, Ana; González-Prieto, Serafín J

    2006-04-15

    Soil CO2 effluxes from recently added 13C-labeled phytomass versus endogenous soil organic matter (SOM) were studied in an acid soil from Atlantic pine forests (NW Spain). After several cultures to incorporate fresh 13C-enriched Lolium perenne to a Humic Cambisol with predominance of humus--Al over humus--Fe complexes, potential soil C mineralization was determined by laboratory aerobic incubation (84 days). Isotopic 13C analyses of SOM fractions were assessed to know in which organic compartments the 13C was preferentially incorporated. Although in the 13C-labeled soil the C mineralization coefficient totalized less than 3% of soil C, the 13C mineralization coefficient exceeded 14%, indicating a greater lability of the newly incorporated organic matter. Organic compounds coming from added phytomass showed a higher lability and contributed considerably to the total soil CO2 effluxes (52% of total soil CO2 evolved during the first decomposition stages and 27% at the end), even though added-C comprised less than 4% of total soil C. Good determination coefficients, when values of CO2--C released were fitted to a first-order double exponential kinetic model, support the existence of two C pools of different lability. Kinetic parameters obtained with this model indicated that phytomass addition augmented the biodegradability of the labile pool (instantaneous mineralization rate k increased from 0.07 d(-1) to 0.12 d(-1)) but diminished that of the recalcitrant pool (instantaneous mineralization rate h decreased from 2.7 x 10(-4) d(-1) to 1.6 x 10(-4) d(-1)). Consequently, the differentiation between both SOM pools increased, showing the importance of SOM quality on CO2 emissions from this kind of soil to the atmosphere.

  12. Long-term response of nutrient-limited forests to CO[sub 2] enrichment; equilibrium behavior of plant-soil models

    Energy Technology Data Exchange (ETDEWEB)

    Comins, H.N.; McMurtrie, R.E. (Univ. of New South Wales, Kensington (Australia))

    1993-11-01

    Established process-based models of forest biomass production in relation to atmospheric CO[sub 2] concentration (McMurtrie 1991) and soil carbon/nutrient dynamics (Parton et al. 1987) are integrated to derive the [open quotes]Generic Decomposition and Yield[close quotes] model (G'DAY). The model is used to describe how photosynthesis and nutritional factors interact to determine the productivity of forest growing under nitrogen-limited conditions. A simulated instantaneous doubling of atmospheric CO[sub 2] concentration lead to a growth response that is initially large (27% above productivity at current CO[sub 2]) but declines to <10% elevation within 5 yr. The decline occurs because increases in photosynthetic carbon gain at elevated CO[sub 2] are not matched by increases in nutrient supply. Lower foliar N concentrations at elevated CO[sub 2] have two countervailing effects on forest production: decreased rates of N cycling between vegetation and soils (with negative consequences for productivity), and reduced rates of N loss through gaseous emission, fire, and leaching. Theoretical analysis reveals that there is an enduring response to CO[sub 2] enrichment, but that the magnitude of the long-term equilibrium response is extremely sensitive to the assumed rate of gaseous emission resulting from mineralization of nitrogen. Theory developed to analyze G'DAY is applicable to other published production-decomposition models describing the partitioning of soil carbon among compartments with widely differing decay-time constants. 37 refs., 9 figs., 2 tabs.

  13. Advanced enrichment techniques

    International Nuclear Information System (INIS)

    Johnson, A.

    1988-01-01

    BNFL is in a unique position in that it has commercial experience of diffusion enrichment, and of centrifuge enrichment through its associate company Urenco. In addition BNFL is developing laser enrichment techniques as part of a UK development programme in this area. The paper describes the development programme which led to the introduction of competitive centrifuge enrichment technology by Urenco and discusses the areas where improvements have and will continue to be made in the centrifuge process. It also describes the laser development programme currently being undertaken in the UK. The paper concludes by discussing the relative merits of the various methods of uranium enrichment, with particular reference to the enrichment market likely to obtain over the rest of the century

  14. Uranium enrichment plans and policies

    International Nuclear Information System (INIS)

    Schwennesen, J.L.

    1981-01-01

    Significant progress has been made in US efforts to expand its enrichment capacity. The Cascade Improvement Program (CIP) and Cascade Upgrading Program (CUP) are now complete at Oak Ridge and Paducah and almost complete at Portsmouth. Considerable progress has also been made in constructing the Gas Centrifuge Enrichment Plant (GCEP), and physical construction of the first process building is well under way. Current plans are to have two process buildings on-line by 1989 with the remaining six buildings to be added sequentially as needed to meet demand. The status of DOE enrichment services contracts is essentially unchanged from that reported at last year's seminar. The OUEA latest forecast of nuclear power growth, however, is considerably lower than reported last year, although a leveling trend is becoming apparent. The Variable Tails Assay Option (VTAO) of the AFC contract was made available for the third time for FY 1983. The DOE inventories of natural uranium still remain high. The Department of Energy will dispose of this material by using it for Government programs and for enrichment plant operations. It appears that Government inventories of uranium are adequate through at least the mid-1990s. It remains DOE policy not to dispose of its natural uranium stocks through direct sales in the marketplace, except for very small quantities or if an emergency situation would exist and all reasonable attempts had been made, without success, to obtain natural uranium from commercial sources. Finally, with regard to DOE plans on future transaction tails assays, it still appears likely that the current 0.20 percent uranium-235 reference tails assay will be maintained until well into the 1990s, at which time it might be increased up to 0.25 percent uranium-235

  15. Uranium enrichment: an overview

    Energy Technology Data Exchange (ETDEWEB)

    Cazalet, J.

    1995-12-31

    This paper is a general presentation of uranium enrichment processes and assessments of the prevailing commercial and industrial situations. It gives first some theoretical aspects of enrichment in general and explains the differences between statistical and selective processes in particular. Then a review of the different processes is made with a comparison between them. Finally, some general remarks concerning applications are given and the risks of proliferation related to enrichment are mentioned. (J.S.). 4 refs., 5 figs., 8 tabs.

  16. Uranium enrichment: an overview

    International Nuclear Information System (INIS)

    Cazalet, J.

    1995-01-01

    This paper is a general presentation of uranium enrichment processes and assessments of the prevailing commercial and industrial situations. It gives first some theoretical aspects of enrichment in general and explains the differences between statistical and selective processes in particular. Then a review of the different processes is made with a comparison between them. Finally, some general remarks concerning applications are given and the risks of proliferation related to enrichment are mentioned. (J.S.). 4 refs., 5 figs., 8 tabs

  17. Boron carbide synthesis by carbothermic reduction of boron oxide

    International Nuclear Information System (INIS)

    Castro, A.R.M. de; Paschoal, J.O.A.

    1988-01-01

    Boron carbide (B 4 C) is a ceramic material of technological applications due to its extreme hardness and high chemical as well as thermal stability. Some parameters of the process for obtaining B 4 C by carbothermic reduction of B 2 O 3 have been determined. The starting powders and the final products have been analysed by chemical, spectrographic and X-ray diffraction methods. The results show that the B 4 C obtained by the carbothermic reduction process is suitable for applications with a definite determination of the free carbon content. (author) [pt

  18. Boron Carbides As Thermo-electric Materials

    Science.gov (United States)

    Wood, Charles

    1988-01-01

    Report reviews recent theoretical and experimental research on thermoelectric materials. Recent work with narrow-band semiconductors demonstrated possibility of relatively high thermoelectric energy-conversion efficiencies in materials withstanding high temperatures needed to attain such efficiencies. Among promising semiconductors are boron-rich borides, especially boron carbides.

  19. Boron carbide whiskers produced by vapor deposition

    Science.gov (United States)

    1965-01-01

    Boron carbide whiskers have an excellent combination of properties for use as a reinforcement material. They are produced by vaporizing boron carbide powder and condensing the vapors on a substrate. Certain catalysts promote the growth rate and size of the whiskers.

  20. Hot flow behavior of boron microalloyed steels

    International Nuclear Information System (INIS)

    Lopez-Chipres, E.; Mejia, I.; Maldonado, C.; Bedolla-Jacuinde, A.; El-Wahabi, M.; Cabrera, J.M.

    2008-01-01

    This research work studies the effect of boron contents on the hot flow behavior of boron microalloyed steels. For this purpose, uniaxial hot-compression tests were carried out in a low carbon steel microalloyed with four different amounts of boron over a wide range of temperatures (950, 1000, 1050 and 1100 deg. C) and constant true strain rates (10 -3 , 10 -2 and 10 -1 s -1 ). Experimental results revealed that both peak stress and peak strain tend to decrease as boron content increases, which indicates that boron additions have a solid solution softening effect. Likewise, the flow curves show a delaying effect on the kinetics of dynamic recrystallization (DRX) when increasing boron content. Deformed microstructures show a finer austenitic grain size in the steel with higher boron content (grain refinement effect). Results are discussed in terms of boron segregation towards austenitic grain boundaries during plastic deformation, which increases the movement of dislocations, enhances the grain boundary cohesion and modificates the grain boundary structure

  1. Compression and associated properties of boron carbide

    Science.gov (United States)

    Ciezak, Jennifer; Dandekar, Dattatraya

    2009-06-01

    The observed loss of shear strength of boron carbide around 22 GPa has been attributed to presence of amorphous material in the shock recovered, and statically indented and pressurized boron carbide. The present work presents a more direct association of the observed loss of shear strength in boron carbide under plane shock wave compression to amorphization in boron carbide under triaxial stress compression. This evidence is obtained from in-situ measurement of Raman, and infrared vibrational spectra of boron carbide confined in a Diamond Anvil Cell (DAC) under hydrostatic and non-hydrostatic pressures. X-ray-diffraction measurements do show a shift in the compression of boron carbide around 27 GPa. However, X-ray diffraction measurements indicate that the amorphization does not extend to micron scale, as there is no evidence of a loss of crystallinity in the recorded diffraction pattern of boron carbide to 47 GPa. Our work shows that shear plays a very dominant role in the stress-induced amorphization of boron carbide.

  2. Ultratough single crystal boron-doped diamond

    Science.gov (United States)

    Hemley, Russell J [Carnegie Inst. for Science, Washington, DC ; Mao, Ho-Kwang [Carnegie Inst. for Science, Washington, DC ; Yan, Chih-Shiue [Carnegie Inst. for Science, Washington, DC ; Liang, Qi [Carnegie Inst. for Science, Washington, DC

    2015-05-05

    The invention relates to a single crystal boron doped CVD diamond that has a toughness of at least about 22 MPa m.sup.1/2. The invention further relates to a method of manufacturing single crystal boron doped CVD diamond. The growth rate of the diamond can be from about 20-100 .mu.m/h.

  3. Spectral tailoring for boron Neutron capture therapy

    NARCIS (Netherlands)

    Nievaart, V.A.

    2007-01-01

    In several places in the world, such as Petten and Delft in the Netherlands, investigations are in progress in the fight against certain types of cancer with Boron Neutron Capture Therapy. The basic idea is very simple: boron is loaded only into the cancer cells, using a special drug, after which

  4. Fabrication of boron-phosphide neutron detectors

    International Nuclear Information System (INIS)

    Fitzsimmons, M.; Pynn, R.

    1997-01-01

    Boron phosphide is a potentially viable candidate for high neutron flux neutron detectors. The authors have explored chemical vapor deposition methods to produce such detectors and have not been able to produce good boron phosphide coatings on silicon carbide substrates. However, semi-conducting quality films have been produced. Further testing is required

  5. Possible toxicity of boron on sugar cane

    Energy Technology Data Exchange (ETDEWEB)

    Bravo C., M.

    Analyses of necrotic and green leaf tissues from sugar cane grown in the Tambo Valley (Arequipa, Peru) have shown that the boron concentration in necrotic tissue (average 657.7 ppm) is several times higher than that in the green tissue (average 55.7 ppm). This suggests that the necrosis may be due to boron toxicity.

  6. Study of boron detection limit using the in-air PIGE set-up at LAMFI-USP

    International Nuclear Information System (INIS)

    Moro, M. V.; Silva, T. F.; Trindade, G. F.; Added, N.; Tabacniks, M. H.

    2014-01-01

    The quantification of small amounts of boron in materials is of extreme importance in different areas of materials science. Boron is an important contaminant and also a silicon dopant in the semiconductor industry. Boron is also extensively used in nuclear power plants, either for neutron shielding or for safety control and boron is an essential nutrient for life, either vegetable or animal. The production of silicon solar cells, by refining metallurgical-grade silicon (MG-Si) requires the control and reduction of several silicon contaminants to very low concentration levels. Boron is one of the contaminants of solar-grade silicon (SG-Si) that must be controlled and quantified at sub-ppm levels. In the metallurgical purification, boron quantification is usually made by Inductive Coupled Plasma Mass Spectrometry, (ICP-MS) but the results need to be verified by an independent analytical method. In this work we present the results of the analysis of silicon samples by Particle Induced Gamma-Ray Emission (PIGE) aiming the quantification of low concentrations of boron. PIGE analysis was carried out using the in-air external beam line of the Laboratory for Materials Analysis with Ion Beams (LAMFI-USP) by the 10 B(p,αγ( 7 Be nuclear reaction, and measuring the 429 keV γ-ray. The in-air PIGE measurements at LAMFI have a quantification limit of the order of 10 16 at/cm 2

  7. Identification of proteins ınvolved in excess boron stress response in ...

    African Journals Online (AJOL)

    Aylin Eşiz Dereboylu

    2011-11-07

    Nov 7, 2011 ... affects every aspect of plant physiology and metabolism. The physiological effects of boron toxicity include reduced root cell division (Liu et al., 2000), decreased shoot and root growth (Lowatt and Bates, 1984; Nable et al., 1990), decrease in leaf chlorophyll, inhibition of photosynthesis, lower stomatal ...

  8. Impact of different environmental stimuli on the release of 1-MCP from boron-MCP complexes

    Science.gov (United States)

    In our previous report, boron derivatives of methylene cyclopropane complexes (B-MCP) were developed to stabilize the gaseous 1-MCP (1-methylcyclopropene), a commercial plant growth regulator, for eventual release in open crop fields when under humid conditions or in contact with water. To meet the ...

  9. Continuum modeling of boron nitride nanotubes

    International Nuclear Information System (INIS)

    Song, J; Wu, J; Hwang, K C; Huang, Y

    2008-01-01

    Boron nitride nanotubes display unique properties and have many potential applications. A finite-deformation shell theory is developed for boron nitride nanotubes directly from the interatomic potential to account for the effect of bending and curvature. Its constitutive relation accounts for the nonlinear, multi-body atomistic interactions, and therefore can model the important effect of tube chirality and radius. The theory is then used to determine whether a single-wall boron nitride nanotube can be modeled as a linear elastic isotropic shell. Instabilities of boron nitride nanotubes under different loadings (e.g., tension, compression, and torsion) are also studied. It is shown that the tension instability of boron nitride nanotubes is material instability, while the compression and torsion instabilities are structural instabilities.

  10. Stabilization of boron carbide via silicon doping.

    Science.gov (United States)

    Proctor, J E; Bhakhri, V; Hao, R; Prior, T J; Scheler, T; Gregoryanz, E; Chhowalla, M; Giulani, F

    2015-01-14

    Boron carbide is one of the lightest and hardest ceramics, but its applications are limited by its poor stability against a partial phase separation into separate boron and carbon. Phase separation is observed under high non-hydrostatic stress (both static and dynamic), resulting in amorphization. The phase separation is thought to occur in just one of the many naturally occurring polytypes in the material, and this raises the possibility of doping the boron carbide to eliminate this polytype. In this work, we have synthesized boron carbide doped with silicon. We have conducted a series of characterizations (transmission electron microscopy, scanning electron microscopy, Raman spectroscopy and x-ray diffraction) on pure and silicon-doped boron carbide following static compression to 50 GPa non-hydrostatic pressure. We find that the level of amorphization under static non-hydrostatic pressure is drastically reduced by the silicon doping.

  11. Uranium enrichment: heading for the abyss

    International Nuclear Information System (INIS)

    Norman, C.

    1983-01-01

    This article discusses the federal government's $2.3 billion a year business enriching uranium for nuclear power plants which is heading toward a major crisis. Due to miscalculations by the Department of Energy, it is caught with billions of dollars of construction in progress just as projected demand for enriched uranium is decreasing. At the center of the controversy is the Gas Centrifuge Plant at Portsmouth, Ohio - estimated to cost $10 billion dollars. A review of how DOE got into this situation and how they plan to solve it is presented

  12. Analysis of boron nitride by flame spectrometry methods

    International Nuclear Information System (INIS)

    Telegin, G.F.; Chapysheva, G.Ya.; Shilkina, N.N.

    1989-01-01

    A rapid method has been developed for determination of free and total boron contents as well as trace impurities in boron nitride by using autoclave sample decomposition followed by atomic emission and atomic absorption determination. The relative standard deviation is not greater than 0.03 in the determination of free boron 0.012 in the determination of total boron content

  13. Evaluation of Ground-Water and Boron Sources by Use of Boron Stable-Isotope Ratios, Tritium, and Selected Water-Chemistry Constituents near Beverly Shores, Northwestern Indiana, 2004

    Science.gov (United States)

    Buszka, Paul M.; Fitzpatrick, John A.; Watson, Lee R.; Kay, Robert T.

    2007-01-01

    from human-affected boron sources. Boron concentrations in potential ground-water sources of boron were largest (15,700 to 24,400 ?g/L) in samples of CCP-affected surficial aquifer water from four wells at a CCP landfill and smallest (27 to 63 ?g/L) in three wells in the surficial aquifer that were distant from human-affected boron sources. Boron concentrations in water from the basal sand aquifer ranged from 656 ?g/L to 1,800 ?g/L. Boron concentrations in water from three domestic-wastewater-affected surficial aquifer wells ranged from 84 to 387 ?g/L. Among the representative ground-water samples, boron concentrations from all four samples of CCP-affected surficial aquifer water and four of five samples of water from the basal sand aquifer had concentrations greater than the RAL. A comparison of boron concentrations in acid-preserved and unacidified samples indicated that boron concentrations reported for this investigation may be from about 11 to 16 percent less than would be reported in a standard analysis of an acidified sample. The stable isotope boron-11 was most enriched in comparison to boron-10 in ground water from a confined aquifer, the basal sand aquifer (d11B, 24.6 to 34.0 per mil, five samples); it was most depleted in CCP-affected water from the surficial aquifer (d11B, 0.1 to 6.6 per mil, four samples). Domestic-wastewater-affected water from the surficial aquifer (d11B, 8.7 to 11.7 per mil, four samples) was enriched in boron-11, in comparison to individual samples of a borax detergent additive and a detergent with perborate bleach; it was intermediate in composition between basal sand aquifer water and CCP-affected water from the surficial aquifer. The similarity between a ground-water sample from the surficial aquifer and a hypothetical mixture of unaffected surficial aquifer and basal sand aquifer waters indicates the potential for long-term upward discharge of ground water into the surficial aquifer from one or more confined aquifers. Est

  14. Chemical vapor deposited boron carbide

    International Nuclear Information System (INIS)

    Mackinnon, I.D.R.; Smith, K.L.

    1987-01-01

    Detailed analytical electron microscope (AEM) studies of yellow whiskers produced by chemical vapor deposition (CVD) show that two basic types of whiskers are produced at low temperatures (between 1200 0 C and 1400 0 C) and low boron to carbon gas ratios. Both whisker types show planar microstructures such as twin planes and stacking faults oriented parallel to, or at a rhombohedral angle to, the growth direction. For both whisker types, the presence of droplet-like terminations containing both Si and Ni indicate that the growth process during CVD is via a vapor-liquid-solid (VLS) mechanisms

  15. Positron annihilation in boron nitride

    Directory of Open Access Journals (Sweden)

    N.Amrane

    2006-01-01

    Full Text Available Electron and positron charge densities are calculated as a function of position in the unit cell for boron nitride. Wave functions are derived from pseudopotential band structure calculations and the independent particle approximation (IPM, respectively, for electrons and positrons. It is observed that the positron density is maximum in the open interstices and is excluded not only from ion cores but also to a considerable degree from valence bonds. Electron-positron momentum densities are calculated for (001,110 planes. The results are used in order to analyse the positron effects in BN.

  16. Boron carbide-carbon composites and composites for cryogenic applications

    International Nuclear Information System (INIS)

    Sheinberg, H.

    1979-01-01

    Because of its neutronic properties, high hardness, and high melting temperature, boron carbide (B 4 C) is widely used at the Los Alamos Scientific Laboratory. However because of its hardness and mode of manufacture, it is expensive to machine finish to tight dimensional specifictions. For some neutronic applications, a density considerably below the theoretical 2.52 Mg/m 3 was acceptable, and this relaxation in density specification permitted addition of carbon as a second phase to reduce machining costs. We conducted an experimental program to prepare 50.8-mm-diam by 34.8-mm-thick cylinders of B 4 C and B 4 C-C composites with concentrations of carbon varying from 5.5 to 30 volume percent. Additionally we used three forms of carbon, natural flake graphite, synthetic graphite flour, and a fine furnace black as the source of the second phase. We determined the sound velocity, compressive strength, coefficient of thermal expansion, electrical resistivity, and microstructure as functions of composition. Additionally, an enriched boron ( 10 B)-carbon composite was studied as an alternate material

  17. Experimental boron neutron capture therapy for melanoma: Systemic delivery of boron to melanotic and amelanotic melanoma

    International Nuclear Information System (INIS)

    Coderre, J.A.; Glass, J.D.; Micca, P.; Greenberg, D.; Packer, S.

    1990-01-01

    The boron-containing melanin precursor analogue p-boronophenylalanine (BPA) has previously been shown to selectively deliver boron to pigmented murine melanomas when administered in a single intragastric dose. If boron neutron capture therapy is to become a clinically useful method of radiation therapy for human malignant melanoma, the boron carrier must be capable of delivering useful amounts of boron to remote tumor sites (metastases) and to poorly pigmented melanomas. The authors have now determined the ability of BPA to accumulate in several nonpigmented melanoma models including human melanoma xenografts in nude mice. The absolute amount of boron in the nonpigmented melanomas was about 50% of the observed in the pigmented counterparts but was still selectively concentrated in the tumor relative to normal tissues in amounts sufficient for effective neutron capture therapy. Single intragastric doses of BPA resulted in selective localization of boron in the amelanotic Greene melanoma carried in the anterior chamber of the rabbit eye and in a pigmented murine melanoma growing in the lungs. The ratio of the boron concentration in these tumors to the boron concentration in the immediately adjacent normal tissue was in the range of 3:1 to 4:1. These distribution studies support the proposal that boron neutron capture therapy may be useful as a regional therapy for malignant melanoma

  18. Uranium enrichment plans

    International Nuclear Information System (INIS)

    Gagne, R.W.; Thomas, D.C.

    1977-01-01

    The status of existing uranium enrichment contracts in the US is reviewed and expected natural uranium requirements for existing domestic uranium enrichment contracts are evaluated. Uncertainty in natural uranium requirements associated with requirements-type and fixed-commitment type contracts is discussed along with implementation of variable tails assay

  19. Study of ceramic mixed boron element as a neutron shielding

    International Nuclear Information System (INIS)

    Ismail Mustapha; Mohd Reusmaazran Yusof; Md Fakarudin Ab Rahman; Nor Paiza Mohamad Hasan; Samihah Mustaffha; Yusof Abdullah; Mohamad Rabaie Shari; Airwan Affandi Mahmood; Nurliyana Abdullah; Hearie Hassan

    2012-01-01

    Shielding upon radiation should not be underestimated as it can causes hazard to health. Precautions on the released of radioactive materials should be well concerned and considered. Therefore, the combination of ceramic and boron make them very useful for shielding purpose in areas of low and intermediate neutron. A six grades of ceramic tile have been produced namely IMN05 - 5 % boron, IMN06 - 6 % boron, IMN07 - 7 % boron, IMN08 - 8 % boron, IMN09 - 9 % boron, IMN10 - 10 % boron from mixing, press and sintered process. Boron is a material that capable of absorbing and capturing neutron, so that neutron and gamma test were conducted to analyze the effectiveness of boron material in combination with ceramic as shielding. From the finding, percent reduction number of count per minute shows the ceramic tiles are capable to capture neutron. Apart from all the percentage of boron used, 10 % is the most effective shields since the percent reduction indicating greater neutron captured increased. (author)

  20. Analysis of Boron Distribution in Steel using Neutron at HANARO

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Eun-Joo; Seong, Baek-Seok; Kim, Hark-Rho [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2007-07-01

    Boron is very useful element in steels to improve the mechanical properties. In steel matrix, boron exist several types such as solute, segregation in grain boundary and many kinds of precipitate, which influence the properties of the steel. But, detecting of boron using X-ray or ion-beam is not easy because boron is very light atom than iron. However neutron gives the clear image of boron distribution from the particle tracking autoradiography (PTA) method. The PTA method of boron uses the phenomenon that boron irradiated by neutron emits Liion and alpha particle. Boron distribution can be obtained by observing the traces of the emitted Li-ion and alpha particle. At HANARO, the study for observing of boron distribution has been performed several years ago. Recently, the experimental techniques were improved for the reactor power of 30 MW. In this paper, improved experimental techniques were described and some results for boron added low-carbon steel plate were introduced.

  1. tassel-less1 encodes a boron channel protein required for inflorescence development in maize.

    Science.gov (United States)

    Leonard, April; Holloway, Beth; Guo, Mei; Rupe, Mary; Yu, GongXin; Beatty, Mary; Zastrow-Hayes, Gina; Meeley, Robert; Llaca, Victor; Butler, Karlene; Stefani, Tony; Jaqueth, Jennifer; Li, Bailin

    2014-06-01

    tassel-less1 (tls1) is a classical maize (Zea mays) inflorescence mutant. Homozygous mutant plants have no tassels or very small tassels, and ear development is also impaired. Using a positional cloning approach, ZmNIP3;1 (a NOD26-like intrinsic protein) was identified as the candidate gene for tls1. The ZmNIP3;1 gene is completely deleted in the tls1 mutant genome. Two Mutator-insertional TUSC alleles of ZmNIP3;1 exhibited tls1-like phenotypes, and allelism tests confirmed that the tls1 gene encodes ZmNIP3;1. Transgenic plants with an RNA interference (RNAi) construct to down-regulate ZmNIP3;1 also showed tls1-like phenotypes, further demonstrating that TLS1 is ZmNIP3;1. Sequence analysis suggests that ZmNIP3;1 is a boron channel protein. Foliar application of boron could rescue the tls1 phenotypes and restore the normal tassel and ear development. Gene expression analysis indicated that in comparison with that of the wild type or tls1 plants treated with boron, the transition from the vegetative to reproductive phase or the development of the floral meristem is impaired in the shoot apical meristem of the tls1 mutant plants. It is concluded that the tls1 mutant phenotypes are caused by impaired boron transport, and boron is essential for inflorescence development in maize. © The Author 2014. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  2. Improved detection of extended spectrum beta-lactamase (ESBL-producing Escherichia coli in input and output samples of German biogas plants by a selective pre-enrichment procedure.

    Directory of Open Access Journals (Sweden)

    Thorsten Schauss

    Full Text Available The presence of extended-spectrum beta-lactamase (ESBL-producing Escherichia coli was investigated in input (manure from livestock husbandry and output samples of six German biogas plants in 2012 (one sampling per biogas plant and two German biogas plants investigated in an annual cycle four times in 2013/2014. ESBL-producing Escherichia coli were cultured by direct plating on CHROMagar ESBL from input samples in the range of 100 to 104 colony forming units (CFU per g dry weight but not from output sample. This initially indicated a complete elimination of ESBL-producing E. coli by the biogas plant process. Detected non target bacteria were assigned to the genera Acinetobacter, Pseudomonas, Bordetella, Achromobacter, Castellaniella, and Ochrobactrum. A selective pre-enrichment procedure increased the detection efficiency of ESBL-producing E. coli in input samples and enabled the detection in five of eight analyzed output samples. In total 119 ESBL-producing E. coli were isolated from input and 46 from output samples. Most of the E. coli isolates carried CTX-M-type and/or TEM-type beta lactamases (94%, few SHV-type beta lactamase (6%. Sixty-four blaCTX-M genes were characterized more detailed and assigned mainly to CTX-M-groups 1 (85% and 9 (13%, and one to group 2. Phylogenetic grouping of 80 E. coli isolates showed that most were assigned to group A (71% and B1 (27%, only one to group D (2%. Genomic fingerprinting and multilocus sequence typing (MLST showed a high clonal diversity with 41 BOX-types and 19 ST-types. The two most common ST-types were ST410 and ST1210. Antimicrobial susceptibility testing of 46 selected ESBL-producing E. coli revealed that several isolates were additionally resistant to other veterinary relevant antibiotics and some grew on CHROMagar STEC but shiga-like toxine (SLT genes were not detected. Resistance to carbapenems was not detected. In summary the study showed for the first time the presence of ESBL-producing E

  3. Improved Detection of Extended Spectrum Beta-Lactamase (ESBL)-Producing Escherichia coli in Input and Output Samples of German Biogas Plants by a Selective Pre-Enrichment Procedure

    Science.gov (United States)

    Schauss, Thorsten; Glaeser, Stefanie P.; Gütschow, Alexandra; Dott, Wolfgang; Kämpfer, Peter

    2015-01-01

    The presence of extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli was investigated in input (manure from livestock husbandry) and output samples of six German biogas plants in 2012 (one sampling per biogas plant) and two German biogas plants investigated in an annual cycle four times in 2013/2014. ESBL-producing Escherichia coli were cultured by direct plating on CHROMagar ESBL from input samples in the range of 100 to 104 colony forming units (CFU) per g dry weight but not from output sample. This initially indicated a complete elimination of ESBL-producing E. coli by the biogas plant process. Detected non target bacteria were assigned to the genera Acinetobacter, Pseudomonas, Bordetella, Achromobacter, Castellaniella, and Ochrobactrum. A selective pre-enrichment procedure increased the detection efficiency of ESBL-producing E. coli in input samples and enabled the detection in five of eight analyzed output samples. In total 119 ESBL-producing E. coli were isolated from input and 46 from output samples. Most of the E. coli isolates carried CTX-M-type and/or TEM-type beta lactamases (94%), few SHV-type beta lactamase (6%). Sixty-four bla CTX-M genes were characterized more detailed and assigned mainly to CTX-M-groups 1 (85%) and 9 (13%), and one to group 2. Phylogenetic grouping of 80 E. coli isolates showed that most were assigned to group A (71%) and B1 (27%), only one to group D (2%). Genomic fingerprinting and multilocus sequence typing (MLST) showed a high clonal diversity with 41 BOX-types and 19 ST-types. The two most common ST-types were ST410 and ST1210. Antimicrobial susceptibility testing of 46 selected ESBL-producing E. coli revealed that several isolates were additionally resistant to other veterinary relevant antibiotics and some grew on CHROMagar STEC but shiga-like toxine (SLT) genes were not detected. Resistance to carbapenems was not detected. In summary the study showed for the first time the presence of ESBL-producing E. coli in

  4. Multinational uranium enrichment in the Middle East

    International Nuclear Information System (INIS)

    Ahmad, Ali; Salahieh, Sidra; Snyder, Ryan

    2017-01-01

    The Joint Comprehensive Plan of Action (JCPOA) agreed to by Iran and the P5+1 in July 2015 placed restrictions on Iran’s nuclear program while other Middle Eastern countries– Egypt, Jordan, Saudi Arabia, Turkey, and the United Arab Emirates–are planning to build their own nuclear power plants to meet increasing electricity demands. Although the JCPOA restricts Iran's uranium enrichment program for 10–15 years, Iran's neighbors may choose to develop their own national enrichment programs giving them a potential nuclear weapons capability. This paper argues that converting Iran's national enrichment program to a more proliferation-resistant multinational arrangement could offer significant economic benefits–reduced capital and operational costs–due to economies of scale and the utilization of more efficient enrichment technologies. In addition, the paper examines policy aspects related to financing, governance, and how multinational enrichment could fit into the political and security context of the Middle East. A multinational enrichment facility managed by regional and international partners would provide more assurance that it remains peaceful and could help build confidence between Iran and its neighbors to cooperate in managing other regional security challenges. - Highlights: • Freezing Iran's nuclear program is an opportunity to launch joint initiatives in ME. • A joint uranium enrichment program in the Middle East offers economic benefits. • Other benefits include improved nuclear security and transparency in the region.

  5. Optimization of neutron flux using fission converter plates for Boron Neutron Capture Therapy study in Tehran reactor

    International Nuclear Information System (INIS)

    Hamidi, S.; Babaei, H.

    2003-01-01

    Boron Neutron Capture Therapy is a binary from of radiation therapy for treatment of deep seated brain tumor, based on the nuclear reaction that occur when boron ( 10 B) is exposed to the thermal neutrons. The stable isotope 10 B is irradiated with low energy or thermal neutrons to yield 4 He nuclei (i.e a particles) and recoiling 7 Li ions. These are absorbed in tumor cells and released their energy in them and destroy tumor cells. This work has tried to optimize neutron flux from Tehran reactor in order to be used in a Boron Neutron Capture Therapy program. Fission converter plates (20% enriched Uranium) have been applied to increase the neutron flux

  6. Composite boron nitride neutron detectors

    Science.gov (United States)

    Roth, M.; Mojaev, E.; Khakhan, O.; Fleider, A.; Dul`kin, E.; Schieber, M.

    2014-09-01

    Single phase polycrystalline hexagonal boron nitride (BN) or mixed with boron carbide (BxC) embedded in an insulating polymeric matrix acting as a binder and forming a composite material as well as pure submicron size polycrystalline BN has been tested as a thermal neutron converter in a multilayer thermal neutron detector design. Metal sheet electrodes were covered with 20-50 μm thick layers of composite materials and assembled in a multi-layer sandwich configuration. High voltage was applied to the metal electrodes to create an interspacing electric field. The spacing volume could be filled with air, nitrogen or argon. Thermal neutrons were captured in converter layers due to the presence of the 10B isotope. The resulting nuclear reaction produced α-particles and 7Li ions which ionized the gas in the spacing volume. Electron-ion pairs were collected by the field to create an electrical signal proportional to the intensity of the neutron source. The detection efficiency of the multilayer neutron detectors is found to increase with the number of active converter layers. Pixel structures of such neutron detectors necessary for imaging applications and incorporation of internal moderator materials for field measurements of fast neutron flux intensities are discussed as well.

  7. Boron-Proton Nuclear-Fusion Enhancement Induced in Boron-Doped Silicon Targets by Low-Contrast Pulsed Laser

    Directory of Open Access Journals (Sweden)

    A. Picciotto

    2014-08-01

    Full Text Available We show that a spatially well-defined layer of boron dopants in a hydrogen-enriched silicon target allows the production of a high yield of alpha particles of around 10^{9} per steradian using a nanosecond, low-contrast laser pulse with a nominal intensity of approximately 3×10^{16}  W cm^{−2}. This result can be ascribed to the nature of the long laser-pulse interaction with the target and with the expanding plasma, as well as to the optimal target geometry and composition. The possibility of an impact on future applications such as nuclear fusion without production of neutron-induced radioactivity and compact ion accelerators is anticipated.

  8. Boron-Loaded Silicone Rubber Scintillators

    Energy Technology Data Exchange (ETDEWEB)

    Bell, Z.W.; Maya, L.; Brown, G.M.; Sloop, F.V.Jr

    2003-05-12

    Silicone rubber received attention as an alternative to polyvinyltoluene in applications in which the scintillator is exposed to high doses because of the increased resistance of the rubber to the formation of blue-absorbing color centers. Work by Bowen, et al., and Harmon, et al., demonstrated their properties under gamma/x-ray irradiation, and Bell, et al. have shown their response to thermal neutrons. This last work, however, provided an example of a silicone in which both the boron and the scintillator were contained in the rubber as solutes, a formulation which led to the precipitation of solids and sublimation of the boron component. In the present work we describe a scintillator in which the boron is chemically bonded to the siloxane and so avoids the problem of precipitation and loss of boron to sublimation. Material containing up to 18% boron, by weight, was prepared, mounted on photomultipliers, and exposed to both neutron and gamma fluxes. Pulse height spectra showing the neutron and photon response were obtained, and although the light output was found to be much poorer than from samples in which boron was dissolved, the higher boron concentrations enabled essentially 100% neutron absorption in only a few millimeters' thickness of rubber.

  9. Proceedings of workshop on 'Boron Chemistry and Boron Neutron Capture Therapy'

    International Nuclear Information System (INIS)

    Kitaoka, Y.

    1991-07-01

    This volume contains the proceedings of the 3rd Workshop on 'the Boron Chemistry and Boron Neutron Capture Therapy' held on February 12, in 1991. In this workshop, our attention was focused on the chemical nature of boron compounds and the boron neutron capture therapy (BNCT). First, clinical experiences of BNCT in KURRI in 1990 and 1991 were reported (Chap. 3). The feasibility of the gadolinium neutron capture therapy for brain tumors was discussed (Chap. 4). In the chemical field, a rapid spectrophotometric determination of trace amounts of borons in biological samples is described (Chap. 5). The chemical behaviours of p-boronophenylalanine and its analogs in aqueous solutions were investigated by a paper electrophoresis and infrared spectroscopy (Chap. 6). On the molecular design and synthesis of new boron carriers for BNCT, several new synthetic methods for B-10 containing nucleoside derivatives were shown (Chap. 7). (author)

  10. Electrical and thermal conductivities of the graphene, boron nitride and silicon boron honeycomb monolayers

    Energy Technology Data Exchange (ETDEWEB)

    Mousavi, Hamze, E-mail: hamze.mousavi@gmail.com [Department of Physics, Razi University, Kermanshah (Iran, Islamic Republic of); Khodadadi, Jabbar [Department of Physics, Razi University, Kermanshah (Iran, Islamic Republic of); Moradi Kurdestany, Jamshid [Department of Physics and Astronomy, University of Missouri, Columbia, MO 65201 (United States); Yarmohammadi, Zahra [Department of Physics, Razi University, Kermanshah (Iran, Islamic Republic of)

    2016-11-25

    Density of states, electrical and thermal conductivities of electrons in graphene, boron nitride and silicon boron single sheets are studied within the tight-binding Hamiltonian model and Green's function formalism, based on the linear response theory. The results show that while boron nitride keeps significantly the lowest amounts overall with an interval of zero value in low temperatures, due to its insulating nature, graphene exhibits the most electrical and thermal conductivities, slightly higher than silicon boron except for low temperature region where the latter surpasses, owing to its metallic character. This work might make ideas for creating new electronic devices based on honeycomb nanostructures. - Highlights: • Electronic properties of graphene, silicon boron, and boron nitride planes are compared. • Tight-binding Hamiltonian model and Green's function formalism are implemented. • This work might make ideas for creating new electronic devices based on honeycomb nanostructures.

  11. The determination of boron and carbon in reactor grade boron carbide

    International Nuclear Information System (INIS)

    Crossley, D.; Wood, A.J.; McInnes, C.A.J.; Jones, I.G.

    1978-09-01

    The sealed tube method of dissolution at high temperature and pressure has been successfully applied in the analysis of reactor grade boron carbide for the determination of boron. A 50 mg sample of boron carbide is completely dissolved by heating with concentrated nitric acid in a sealed tube at 300 0 C. The boron content of the resultant sample solution is determined by the mannitol potentiometric titration method. The precision of the method for the determination of 2.5 mg of boron using the Harwell automatic potentiometric titrator is 0.2% (coefficient of variation). The carbon content of a boron carbide sample is determined by combustion of the sample at 1050 0 C in a stream of oxygen using vanadium pentoxide to ensure the complete oxidation of the sample. The carbon dioxide produced from the sample is measured manometrically and the precision of the method for the determination of 4 mg of carbon is 0.4% (coefficient of variation). (author)

  12. A scaling approach for fluid mixing in rapid boron-dilution transients

    International Nuclear Information System (INIS)

    Gavrilas, Mirela; Palazov, Vesselin

    1999-01-01

    The issue of rapid-boron dilution transients has been investigated for a decade with few definitive conclusions. The potential reactivity insertion that would result from the transport of a boron-dilute slug to the core region depends on the spatial and temporal concentration of neutron poison in the fluid that penetrates the core. Difficulties in assessing the consequences of a boron-dilution transient lie in the diversity of postulated on-set scenarios, and in the large dependence of the resulting reactivity insertion on plant conditions and geometric features. The University of Maryland (UM) 2 x 4 Thermohydraulic Loop Facility is collecting code validation data for rapid boron-dilution transients. The data has to be representative of the prototype. scaling thus becomes an important consideration. The mixing of the boron-dilute slug with the highly borated coolant present in the primary system is advective-diffusive. Therefore, the scaling approach involves extracting relevant parameters from the advection-diffusion equation. The dimensionless numbers that govern mixing are shown to be the Strouhal and Schmidt numbers. They have to be considered simultaneously to properly scale the flow in the model facility. A closer investigation of the relation between these two numbers reveals that, for fully developed turbulent flows, matching only one of these numbers is sufficient. This conclusion is substantiated by experimental results from Vattenfall. (author)

  13. Quantitative boron detection by neutron transmission method

    International Nuclear Information System (INIS)

    Okka, M.; Genceli, M.; Eren, E.; Bayulken, A.

    2008-01-01

    //Quantitative boron detection is mainly performed by chemical methods like colorimetric titration. High neutron absorption cross section of natural boron makes attractive its detection by absorption measurements. This work is an extension of earlier investigations where neutron radiography technique was used for boron detection. In the present investigation, the neutron absorption rate of boron containing solutions is the way to measure quantitatively the boron content of the solutions. The investigation was carried out in Istanbul TRIGA Mark-II reactor. In the end of the experiments, it was observed that even |ppw| grade boron in aqueous solution can be easily detected. The use of this method is certainly very useful for boron utilizing industries like glass and steel industries.The major disadvantage of the method is the obligation to use always aqueous solutions to be able to detect homogeneously the boron content. Then, steel or glass samples have to be put first in an appropriate solution form. The irradiation of steel samples can give the distribution of boron by the help of a imaging and this suggested method will give its quantitative measurement. The superiority of this method are its quick response time and its accuracy. To test this accuracy, a supposed unknown , solution of boric acid is irradiated and then calculated by the help of the calibration curve. The measured value of boric acid was 0.89 mg and the calculated value was found to be 0.98 mg which gives an accuracy of 10 %. It was also seen that the method is more accurate for low concentration. (authors)

  14. Short-term coral bleaching is not recorded by skeletal boron isotopes.

    Science.gov (United States)

    Schoepf, Verena; McCulloch, Malcolm T; Warner, Mark E; Levas, Stephen J; Matsui, Yohei; Aschaffenburg, Matthew D; Grottoli, Andréa G

    2014-01-01

    Coral skeletal boron isotopes have been established as a proxy for seawater pH, yet it remains unclear if and how this proxy is affected by seawater temperature. Specifically, it has never been directly tested whether coral bleaching caused by high water temperatures influences coral boron isotopes. Here we report the results from a controlled bleaching experiment conducted on the Caribbean corals Porites divaricata, Porites astreoides, and Orbicella faveolata. Stable boron (δ11B), carbon (δ13C), oxygen (δ18O) isotopes, Sr/Ca, Mg/Ca, U/Ca, and Ba/Ca ratios, as well as chlorophyll a concentrations and calcification rates were measured on coral skeletal material corresponding to the period during and immediately after the elevated temperature treatment and again after 6 weeks of recovery on the reef. We show that under these conditions, coral bleaching did not affect the boron isotopic signature in any coral species tested, despite significant changes in coral physiology. This contradicts published findings from coral cores, where significant decreases in boron isotopes were interpreted as corresponding to times of known mass bleaching events. In contrast, δ13C and δ18O exhibited major enrichment corresponding to decreases in calcification rates associated with bleaching. Sr/Ca of bleached corals did not consistently record the 1.2°C difference in seawater temperature during the bleaching treatment, or alternatively show a consistent increase due to impaired photosynthesis and calcification. Mg/Ca, U/Ca, and Ba/Ca were affected by coral bleaching in some of the coral species, but the observed patterns could not be satisfactorily explained by temperature dependence or changes in coral physiology. This demonstrates that coral boron isotopes do not record short-term bleaching events, and therefore cannot be used as a proxy for past bleaching events. The robustness of coral boron isotopes to changes in coral physiology, however, suggests that reconstruction of

  15. Low-Energy Sputtering Studies of Boron Nitride with Xenon Ions

    Science.gov (United States)

    Ray, P. K.; Shutthanandan, V.

    1999-01-01

    Sputtering of boron nitride with xenon ions was investigated using secondary ion (SIMS) and secondary neutral (SNMS) mass spectrometry. The ions generated from the ion gun were incident on the target at an angle of 50' with respect to the surface'normal. The energy of ions ranged from 100 eV to 3 keV. A flood electron gun was used to neutralize the positive charge build-up on the target surface. The intensities of sputtered neutral and charged particles, including single atoms, molecules, and clusters, were measured as a function of ion energy. Positive SIMS spectra were dominated by the two boron isotopes whereas BN- and B- were the two major constituents of the negative SIMS spectra. Nitrogen could be detected only in the SNMS spectra. The intensity-energy curves of the sputtered particles were similar in shape. The knees in P-SIMS and SNMS intensity-energy curves appear at around I keV which is significantly higher that 100 to 200 eV energy range at which knees appear in the sputtering of medium and heavy elements by ions of argon and xenon. This difference in the position of the sputter yield knee between boron nitride and heavier targets is due to the reduced ion energy differences. The isotopic composition of secondary ions of boron were measured by bombarding boron nitride with xenon ions at energies ranging from 100 eV to 1.5 keV using a quadrupole mass spectrometer. An ion gun was used to generate the ion beam. A flood electron gun was used to neutralize the positive charge buildup on the target surface. The secondary ion flux was found to be enriched in heavy isotopes at lower incident ion energies. The heavy isotope enrichment was observed to decrease with increasing primary ion energy. Beyond 350 eV, light isotopes were sputtered preferentially with the enrichment increasing to an asymptotic value of 1.27 at 1.5 keV. The trend is similar to that of the isotopic enrichment observed earlier when copper was sputtered with xenon ions in the same energy

  16. TRIGA low enrichment fuel

    International Nuclear Information System (INIS)

    Gietzen, A.

    1993-01-01

    Sixty TRIGA reactors have been sold and the earliest of these are now passing twenty years of operation. All of these reactors use the uranium-zirconium hydride fuel (UZrH) which provides certain unique advantages arising out of its large prompt negative temperature coefficient, very low fission product release, and high temperature capability. Eleven of these Sixty reactors are conversions from plate fuel to TRIGA fuel which were made as a result of these advantages. With only a few exceptions, TRIGA reactors have always used low-enriched-uranium (LEU) fuel with an enrichment of 19.9%. The exceptions have either been converted from the standard low-enriched fuel to the 70% enriched FLIP fuel in order to achieve extended lifetime, or are higher powered reactors which were designed for long life using 93%-enriched uranium during the time when the use and export of highly enriched uranium (HEU) was not restricted. The advent of international policies focusing attention on nonproliferation and safeguards made the HEU fuels obsolete. General Atomic immediately undertook a development effort (nearly two years ago) in order to be in a position to comply with these policies for all future export sales and also to provide a low-enriched alternative to fully enriched plate-type fuels. This important work was subsequently partially supported by the U.S. Department of Energy. The laboratory and production tests have shown that higher uranium densities can be achieved to compensate for reducing the enrichment to 20%, and that the fuels maintain the characteristics of the very thoroughly proven standard TRIGA fuels. In May of 1978, General Atomic announced that these fuels were available for TRIGA reactors and for plate-type reactors with power levels up to 15 MW with GA's standard commercial warranty

  17. Effect of boron concentration on physicochemical properties of boron-doped carbon nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Keru, Godfrey; Ndungu, Patrick G.; Nyamori, Vincent O., E-mail: nyamori@ukzn.ac.za

    2015-03-01

    Boron-doped carbon nanotubes (B-CNTs) were synthesized using chemical vapour deposition (CVD) floating catalyst method. Toluene was used as the carbon source, triphenylborane as boron as well as the carbon source while ferrocene was used as the catalyst. The amount of triphenylborane used was varied in a solution of toluene and ferrocene. Ferrocene was kept constant at 2.5 wt.%. while a maximum temperature of 900 °C was used for the synthesis of the shaped carbon nanomaterial (SCNMs). SCNMs obtained were characterized by the use of transmission electron microscope (TEM), scanning electron microscope (SEM), high resolution-electron microscope, electron dispersive X-ay spectroscopy (EDX), Raman spectroscopy, inductively coupled plasma-optical emission spectroscopy (ICP-OES), vibrating sample magnetometer (VSM), nitrogen adsorption at 77 K, and inverse gas chromatography. TEM and SEM analysis confirmed SCNMs obtained were a mixture of B-CNTs and carbon nanofibres (B-CNF). EDX and ICP-OES results showed that boron was successively incorporated into the carbon hexagonal network of CNTs and its concentration was dependent on the amount of triphenylborane used. From the VSM results, the boron doping within the CNTs introduced ferromagnetic properties, and as the percentage of boron increased the magnetic coactivity and squareness changed. In addition, boron doping changed the conductivity and the surface energy among other physicochemical properties of B-CNTs. - Highlights: • Boron-doping of carbon nanotubes (CNTs) changes their physiochemical properties. • Amount of boron-doping was dependent on the wt.% of boron precursor used. • Boron-doping changed CNTs surfaces and the distribution of dispersive energy sites. • Boron-doping affected the conductivity and ferromagnetic properties. • Increased boron-doping results in a more favourable interaction with polar probes.

  18. Study on plasma sprayed boron carbide coating

    Science.gov (United States)

    Zeng, Yi; Lee, Soo W.; Ding, Chuanxian

    2002-03-01

    The microstructure, phase composition, and mechanical properties of boron carbide coatings formed by atmospheric plasma spraying (APS) are studied in the present work. The boron carbide coating with high microhardness and low porosity could be produced by APS. The decomposition of boron carbide powder during the plasma spray process would result in the formation of the BxC phase and an increase of the carbon phase, which is confirmed by transmission electron microscopy, x-ray photoelectron spectroscopy, and x-ray diffraction results.

  19. Grafting response to excess boron and expression analysis of genes coding boron transporters in tomato.

    Science.gov (United States)

    Di Gioia, F; Aprile, A; Sabella, E; Santamaria, P; Pardossi, A; Miceli, A; De Bellis, L; Nutricati, E

    2017-09-01

    Boron (B) is essential for plant growth, however its excess in soil and/or in irrigation water can severely compromise plant growth and yield. The goal of this work was to determine whether grafting onto 'Arnold', a commercial interspecific hybrid (Solanum lycopersicum × S. habrochaites) rootstock, which in a previous study was found to be tolerant to salt stress, could improve tomato (S. lycopersicum L. 'Ikram') tolerance to excess B, and whether this effect is associated with an exclusion mechanism. Non-grafted, self-grafted and grafted plants were hydroponically grown in a greenhouse with B concentration in the nutrient solution of 0.27 (control), 5, 10 and 15 mg·l -1 . A transcription analysis was carried out on SlNIP5 and SlBOR1 genes, which encode putative B transporters. Grafting 'Ikram' onto 'Arnold' rootstock reduced B concentration in leaf tissue of plants exposed to B concentrations of 10-15 mg·l -1 . At high B levels, SlNIP5 was down-regulated in all grafting combinations, while SlBOR1 was down-regulated only in the roots of plants grafted onto 'Arnold'. We conclude that grafting the susceptible tomato cultivar 'Ikram' onto the commercial rootstock 'Arnold' improved tolerance to excess B by reducing expression of genes encoding for B transporters at the root level, thus partially reducing the root uptake of B and its accumulation in the shoot. © 2017 German Botanical Society and The Royal Botanical Society of the Netherlands.

  20. Uranium enrichment by centrifuge in Japan

    International Nuclear Information System (INIS)

    Watanabe, T.; Murase, T.

    1977-01-01

    The demand for enriched uranium is on the increase with nuclear power capacity in which the LWR predominates and is estimated to exceed the supply from the present facilities in the world in less than ten years. Therefore, the basic strategy for enriched uranium is investigated on the following three-point long-range program in Japan: 1. To continue negotiations to extend the current allocation by the long-term contract; 2. To seek active participation in international enrichment projects; and 3. To make efforts to develop uranium enrichment technology and to construct inland facilities. On this basis, a vigorous development program of gas centrigue process for industrialization was launched out in 1972 as a national project. Ever since substantial progress in this field has been made and development works have been increased year after year. At present, a concrete plan of a pilot plant is taking shape. Up to now, several types of centrifuges were developed, of which some were completed as prototype models, and subjected to life tests and also to extensive earthquake-resistivity tests for the characteristics of Japanese geological condition. An enrichment plant is composed of so many centrifuges that the installation and piping system of centrifuges is an important factor which has an effect on plant economy and reliability. Two types of the experimental cascade were constructed in Japan. One has been in operation since 1973, and the other since 1975. Valuable empirical data have been accumulated on cascade characteristics, maintenance scheme and so on. It will be important for the coming plants to have a flexibility to escalation of labor and energy cost, or to variation of the separative work requirement and further. An economic prospect of centrifuge enrichment process is presented

  1. URENCO. Uranium enrichment with advanced technology

    International Nuclear Information System (INIS)

    2011-01-01

    URENCO Deutschland is a subsidiary of URENCO Enrichment Company Limited, an international enterprise founded in 1970 in the State Treaty of Almelo, which offers uranium enrichment for nuclear power plants all over the world with the use of advanced technology. URENCO facilities at present are operated in the United Kingdom, the Netherlands, USA, and in Germany. The German URENCO location is Gronau, Westphalia, where cascades have been in operation since 1985 using centrifuge technology to enrich nuclear fuel to up to 5% uranium-235. The URENCO Group supplies nuclear power plants in Europe and overseas countries with a world market share, at present, of more than 25% with a rising tendency. The first uranium separation plant in Gronau (UTA-1) attained its full separation performance of 1,800 t USW/a in late 2005. In February 2005, construction and operation of another plant had been licensed, which can raise the aggregate capacity on site to 4,500 t USW per annum. Construction of the new plant (UTA-2) was begun in summer 2005. UTA-2 will use the latest, most powerful URENCO centrifuge. URENCO has more than 3,500 visitors a year at its German location alone, thus demonstrating its pro-active information policy and offering to the public a maximum of opportunities to acquire information by attending presentations and tours of the plant. (orig.)

  2. The case for enrichment of uranium in Australia

    International Nuclear Information System (INIS)

    George, D.W.

    1981-01-01

    Information is presented on the number of nuclear power plants in operation and under construction and on the extent of the use of uranium. The case for enrichment of uranium in Australia is then considered in detail and the status of feasbility studies being carried out is discussed. Arguments to support an enrichment industry include: the need for additional enrichment capacity; added value; potential profitability; increased employment and industrial opportunities; and retention of depleted uranium

  3. Enriched School Libraries

    Directory of Open Access Journals (Sweden)

    Thijs M. J. Nielen

    2015-12-01

    Full Text Available We compared students from schools with an enriched school library—that is, one with a larger and more up-to-date book collection—with students from schools with a typical school library. We tested effects of an enriched school library on reading motivation, reading frequency, and academic skills. Fourth- and fifth-grade students of 14 schools with an enriched library (n = 272 were compared to fourth and fifth graders from 10 control schools (n = 411. Assignment to the experimental group was external and not determined by participants within schools. Students from schools with enriched libraries scored on average half a standard deviation higher on a standardized reading comprehension test than students from control schools. Mediation analysis revealed that for girls, this effect may have been obtained as a result of an increase in reading motivation and reading frequency. For boys, only reading frequency was a significant mediator.

  4. Boron Doped Graphene 3-Dimensi untuk Superkapasitor Kapasitas Tinggi

    Directory of Open Access Journals (Sweden)

    Nurlia Pramita Sari

    2017-08-01

    Full Text Available Chemical doping is an effective approach to improve the property of carbon material. In this study boron doped graphene with 3D structure used as the electrode was investigated. Boron doped graphene was prepared through freeze-dried process followed by pyrolysis of graphene oxide (GO with three types of chemical substances; boron oxide, boric acid, and boron powder in an argon and hydrogen atmosphere at 1000 C for 3 hours. The difference of chemical composition generated a different percentage of boron bond with GO. The results shows that the highest electrochemical performance was found in graphene samples with the addition of boric acid (BA 86 F/g, followed by boron oxide (BO 59.2 F/g, and boron powder (BP 2 F/g. It can be caused by boron concentration bound with graphene. The higher concentration of boron could be increased the electrochemical performance due to better of ion movement.

  5. Breaking the icosahedra in boron carbide.

    Science.gov (United States)

    Xie, Kelvin Y; An, Qi; Sato, Takanori; Breen, Andrew J; Ringer, Simon P; Goddard, William A; Cairney, Julie M; Hemker, Kevin J

    2016-10-25

    Findings of laser-assisted atom probe tomography experiments on boron carbide elucidate an approach for characterizing the atomic structure and interatomic bonding of molecules associated with extraordinary structural stability. The discovery of crystallographic planes in these boron carbide datasets substantiates that crystallinity is maintained to the point of field evaporation, and characterization of individual ionization events gives unexpected evidence of the destruction of individual icosahedra. Statistical analyses of the ions created during the field evaporation process have been used to deduce relative atomic bond strengths and show that the icosahedra in boron carbide are not as stable as anticipated. Combined with quantum mechanics simulations, this result provides insight into the structural instability and amorphization of boron carbide. The temporal, spatial, and compositional information provided by atom probe tomography makes it a unique platform for elucidating the relative stability and interactions of primary building blocks in hierarchically crystalline materials.

  6. Boron adsorption on hematite and clinoptilolite

    International Nuclear Information System (INIS)

    Gainer, G.M.

    1993-01-01

    This thesis describes experiments performed to determine the suitability of boron as a potential reactive tracer for use in saturated-zone C-well reactive tracer studies for the Yucca Mountain Project (YMP). Experiments were performed to identify the prevalent sorption mechanism of boron and to determine adsorption of boron on hematite and clinoptilolite as a function of pH. These minerals are present in the Yucca Mountain tuff in which the C-well studies will be conducted. Evaluation of this sorption mechanism was done by determining the equilibration time of boron-mineral suspensions, by measuring changes in equilibrium to titrations, and by measuring electrophoretic mobility. Experiments were performed with the minerals suspended in NaCl electrolytes of concentrations ranging from 0.1 N NaCl to 0.001 N NaCl. Experimentalconditions included pH values between 3 and 12 and temperature of about 38 degrees C

  7. Determination of boron in amorphous alloys

    Energy Technology Data Exchange (ETDEWEB)

    Grazhulene, S.S.; Grossman, O.V.; Kuntscher, K.K.; Malygina, L.I.; Muller, E.N.; Telegin, G.F.

    1985-10-01

    In the determination of boron in amorphous alloys containingFe, Co, B, Si, Ni, and P having unusal magnetic and electrical properties, precise analysis and rapid analysis are necessary. To improve the metrological properties of the existing procedure, to find a rapid determination of boron in amorphous alloys, and to verify the accuracy of the results, in the present work the optimization of the photometric determination after extraction of the BF/sup -//sub 4/ ion pair with methylene blue has been studied, and a boron determination by flame photometry using selective methylation has been developed. The determination of boron by the flame photometric and spectrophotometric methods is shown. When a highly precise determination is needed, the spectrophotometric procedure can be used. This procedure is distinguished by its labor intensity and duration. When the need for reproducibility is less severe, the rapid flame photometric procedure is best.

  8. Boron precipitates in ion implanted silicon

    International Nuclear Information System (INIS)

    Wu, W.K.; Washburn, J.

    1975-03-01

    Long rod-like defects are observed in ion implanted silicon when boron is present either as a prior dopant addition or as the implanted species. Results of recent work indicates that these defects have the characteristics of narrow extrinsic dipoles or elongated dislocation loops and that there are two different types along each of the six (110) directions. An annealing kinetics method has been used to identify the nature of these defects formed during post-implantation annealing in boron ion (100 keV) implanted silicon irradiated at room temperature to a dose of 2 x 10 14 /cm 2 . It is concluded that at least two different kinds of rod-like defects exist in boron ion implanted silicon. From the activation energy for shrinkage, it is also concluded that one type (anti A) is composed largely of boron atoms. (U.S.)

  9. Spectromicroscopy in Boron Neutron Capture Therapy Research

    Science.gov (United States)

    Gilbert, Benjamin; Redondo, Jose; Andres, Roger; Suda, Takashi; Neumann, Michael; Steen, Steffi; Gabel, Detlef; Mercanti, Delio; Ciotti, Teresa; Perfetti, Paolo; Margaritondo, Giorgio; de Stasio, Gelsomina

    1998-03-01

    The MEPHISTO synchrotron imaging spectromicroscope can analyse ashed cells or tissue sections to reveal the microdistribution of trace elements. MEPHISTO performs core level x-ray absorption spectroscopy with synchrotron radiation, and uses an electron optics system to provide magnified photoelectron images. An application of the MEPHISTO spectromicroscope is in boron neutron capture therapy (BNCT). BNCT is a binary cancer therapy that will selectively destroy cancer cells provided that compounds containing a boron isotope are selectively accumulated in tumor tissue. Important factors for the success of BNCT include the ability to target every cancer cell, and the distribution of boron inside the cell. To investigate the boron distribution in tissue, sections of human glioblastoma containing a BNCT compound, and stained with nickel against a protein found in the nuclei of proliferating (cancer) cells, were studied with MEPHISTO.

  10. Behaviour of boron in Mandovi estuary (Goa)

    Digital Repository Service at National Institute of Oceanography (India)

    Shirodkar, P.V.; Anand, S.P.

    and alkalinity gave positive correlations with a linear variation. Though the overall behavioural pattern of boron indicated non-conservative nature, it showed a quasi-conservative character during premonsoon and a non-conservative during rest of the seasons...

  11. Boron Drug Delivery via Encapsulated Magnetic Nanocomposites: A New Approach for BNCT in Cancer Treatment

    Directory of Open Access Journals (Sweden)

    Yinghuai Zhu

    2010-01-01

    Full Text Available Ortho-carborane cages have been successfully attached to modified magnetic nanoparticles via catalytic azide-alkyne cycloadditions between 1-R-2-butyl-Ortho-C2B10H10(R=Me,3;Ph,4 and propargyl group-enriched magnetic nanoparticles. A loading amount of 9.83 mmol boron atom/g starch-matrixed magnetic nanoparticles has been reached. The resulting nanocomposites have been found to be highly tumor-targeted vehicles under the influence of an external magnetic field (1.14T, yielding a high boron concentration of 51.4 μg/g tumor and ratios of around 10 : 1 tumor to normal tissues.

  12. Orthorhombic boron oxide under pressure: In situ study by X-ray diffraction and Raman scattering

    Science.gov (United States)

    Cherednichenko, Kirill A.; Le Godec, Yann; Kalinko, Aleksandr; Mezouar, Mohamed; Solozhenko, Vladimir L.

    2016-11-01

    High-pressure phase of boron oxide, orthorhombic β-B2O3, has been studied in situ by synchrotron X-ray diffraction to 22 GPa and Raman scattering to 46 GPa at room temperature. The bulk modulus of β-B2O3 has been found to be 169(3) GPa that is in good agreement with our ab initio calculations. Raman and IR spectra of β-B2O3 have been measured at ambient pressure; all experimentally observed bands have been attributed to the theoretically calculated ones, and the mode assignment has been performed. Based on the data on Raman shift as a function of pressure, combined with equation-of-state data, the Grüneisen parameters of all experimentally observed Raman bands have been calculated. β-B2O3 enriched by 10B isotope has been synthesized, and the effect of boron isotopic substitution on Raman spectra has been studied.

  13. A passive rem counter based on CR39 SSNTD coupled with a boron converter

    CERN Document Server

    Agosteo, S; Ferrarini, c, M; Silari, M

    2009-01-01

    A passive neutron rem counter using a CR39 SSNTD coupled with a boron converter has been developed. The rem counter is a polythene sphere with cadmium and lead insets, designed to have a response function proportional to the fluence to ambient dose equivalent conversion coefficients, H*(10)/Φ, for energies ranging from thermal up to 1 GeV. At its centre is a thermal neutron detector made of a CR39 SSNTD coupled with an enriched boron neutron converter. The rem counter was first calibrated at CERN and at the Politecnico di Milano, and then tested in high-energy neutron fields at GSI, Darmstadt, Germany and at the CERF facility at CERN. Its most important features are a very high neutron sensitivity and conversely a complete insensitivity to gamma radiation.

  14. Boron

    Science.gov (United States)

    ... feeding women over 19 years of age. For adolescents 14 to 18 years of age and pregnant or breast-feeding women 14 to 18 years of age, the ... be expected, is 17 mg per day for adolescents 14 to 18 years of age and pregnant or breast-feeding women 14 to 18 years of age. For ...

  15. Abrasive slurry composition for machining boron carbide

    Science.gov (United States)

    Duran, Edward L.

    1985-01-01

    An abrasive slurry particularly suited for use in drilling or machining boron carbide consists essentially of a suspension of boron carbide and/or silicon carbide grit in a carrier solution consisting essentially of a dilute solution of alkylaryl polyether alcohol in octyl alcohol. The alkylaryl polyether alcohol functions as a wetting agent which improves the capacity of the octyl alcohol for carrying the grit in suspension, yet without substantially increasing the viscosity of the carrier solution.

  16. Boron-rich oligomers for BNCT

    International Nuclear Information System (INIS)

    Gula, M.; Perleberg, O.; Gabel, D.

    2000-01-01

    The synthesis of two BSH derivatives is described, which can be used for oligomerization in DNA-synthesizers. Synthesis pathways lead to final products in five and six steps, respectively. Because of chirality interesting results were expected. NMR-measurements confirm this expectation. Possible oligomers with high concentrations of boron can be attached to biomolecules. These oligomers can be explored with several imaging methods (EELS, PEM) to determine the lower detection limit of boron with these methods. (author)

  17. Review of uranium enrichment prospects in Canada, 1976

    International Nuclear Information System (INIS)

    Developments since 1971 which affect the prospects for uranium enrichment in Canada from the federal government point of view are reviewed. The market for enriched uranium to the year 2000 is similar to that projected in 1971. The committed enrichment capacity of the world will be sufficient until 1990. The Canadian uranium mining capability may be adequate to supply an enrichment plant, but the present reserves policy along with the currently known resources are likely to restrict exports of its products during the plant life. Prices for enriched uranium produced in Canada would be higher than those reported by other proposed new plants; however, newer enrichment techniques have some potential for cost reductions. Application of enrichment with U235 (or plutonium and U233/thorium) to CANDU offers some uranium resource conservation and possible slight power cost reductions. Construction of an enrichment plant in Canada to supply the export market is less attractive in 1976 than in 1971, but there is potential for such a business in the future. (L.L.)

  18. Profile of World Uranium Enrichment Programs-2009

    Energy Technology Data Exchange (ETDEWEB)

    Laughter, Mark D [ORNL

    2009-04-01

    It is generally agreed that the most difficult step in building a nuclear weapon is acquiring fissile material, either plutonium or highly enriched uranium (HEU). Plutonium is produced in a nuclear reactor, whereas HEU is produced using a uranium enrichment process. Enrichment is also an important step in the civil nuclear fuel cycle, in producing low enriched uranium (LEU) for use as fuel for nuclear reactors to generate electricity. However, the same equipment used to produce LEU for nuclear reactor fuel can also be used to produce HEU for weapons. Safeguards at an enrichment plant are the array of assurances and verification techniques that ensure uranium is not diverted or enriched to HEU. There are several techniques for enriching uranium. The two most prevalent are gaseous diffusion, which uses older technology and requires a lot of energy, and gas centrifuge separation, which uses more advanced technology and is more energy efficient. Gaseous diffusion plants (GDPs) provide about 40% of current world enrichment capacity but are being phased out as newer gas centrifuge enrichment plants (GCEPs) are constructed. Estimates of current and future enrichment capacity are always approximate, due to the constant upgrades, expansions, and shutdowns occurring at enrichment plants, largely determined by economic interests. Currently, the world enrichment capacity is approximately 56 million kilogram separative work units (SWU) per year, with 22.5 million in gaseous diffusion and more than 33 million in gas centrifuge plants. Another 34 million SWU/year of capacity is under construction or planned for the near future, almost entirely using gas centrifuge separation. Other less-efficient techniques have also been used in the past, including electromagnetic and aerodynamic separations, but these are considered obsolete, at least from a commercial perspective. Laser isotope separation shows promise as a possible enrichment technique of the future but has yet to be

  19. Discharge cleaning on TFTR after boronization

    International Nuclear Information System (INIS)

    Mueller, D.; Dylla, H.F.; LaMarche, P.H.; Bell, M.G.; Blanchard, W.; Bush, C.E.; Gentile, C.; Hawryluk, R.J.; HIll, K.W.; Janos, A.C.; Jobes, F.C; Owens, D.K.; Pearson, G.; Schivell, J.; Ulrickson, M.A.; Vannoy, C.; Wong, K.L.

    1991-05-01

    At the beginning of the 1990 TFTR experimental run, after replacement of POCO-AXF-5Q graphite tiles on the midplane of the bumper limiter by carbon fiber composite (CFC) tiles and prior to any Pulse Discharge Cleaning (PDC), boronization was performed. Boronization is the deposition of a layer of boron and carbon on the vacuum vessel inner surface by a glow discharge in a diborane, methane and helium mixture. The amount of discharge cleaning required after boronization was substantially reduced compared to that which was needed after previous openings when boronization was not done. Previously, after a major shutdown, about 10 5 low current (∼20 kA) Taylor Discharge Cleaning (TDC) pulses were required before high current (∼400 kA) aggressive Pulse Discharge Cleaning (PDC) pulses could be performed successfully. Aggressive PDC is used to heat the limiters from the vessel bakeout temperature of 150 degrees C to 250 degrees C for a period of several hours. Heating the limiters is important to increase the rate at which water is removed from the carbon limiter tiles. After boronization, the number of required TDC pulses was reduced to <5000. The number of aggressive PDC pulses required was approximately unchanged. 14 refs., 1 tab

  20. Innovative boron nitride-doped propellants

    Directory of Open Access Journals (Sweden)

    Thelma Manning

    2016-04-01

    Full Text Available The U.S. military has a need for more powerful propellants with balanced/stoichiometric amounts of fuel and oxidants. However, balanced and more powerful propellants lead to accelerated gun barrel erosion and markedly shortened useful barrel life. Boron nitride (BN is an interesting potential additive for propellants that could reduce gun wear effects in advanced propellants (US patent pending 2015-026P. Hexagonal boron nitride is a good lubricant that can provide wear resistance and lower flame temperatures for gun barrels. Further, boron can dope steel, which drastically improves its strength and wear resistance, and can block the formation of softer carbides. A scalable synthesis method for producing boron nitride nano-particles that can be readily dispersed into propellants has been developed. Even dispersion of the nano-particles in a double-base propellant has been demonstrated using a solvent-based processing approach. Stability of a composite propellant with the BN additive was verified. In this paper, results from propellant testing of boron nitride nano-composite propellants are presented, including closed bomb and wear and erosion testing. Detailed characterization of the erosion tester substrates before and after firing was obtained by electron microscopy, inductively coupled plasma and x-ray photoelectron spectroscopy. This promising boron nitride additive shows the ability to improve gun wear and erosion resistance without any destabilizing effects to the propellant. Potential applications could include less erosive propellants in propellant ammunition for large, medium and small diameter fire arms.

  1. Exploration of mechanisms regulating ectomycorrhizal colonization of boron-fertilized pine. [Pisolithus tinctorius

    Energy Technology Data Exchange (ETDEWEB)

    Garrett, H.E.; Sword, M.A.

    1991-06-01

    The ectomycorrhizal association is a naturally occurring symbiotic relationship existing between ectomycorrhizal-forming fungi and the root system of some plants, including many coniferous species. Since boron fertilization (BF) has been reported to increase fungal colonization of clover and alfalfa, the effect of BF on fungal colonization and growth of shortleaf pine was examined. Inoculation of seedlings was shown to increase growth responses in boron treated plants. BF increases root sucrose concentrations required for fungal development and improves the nutritional balance of the plant. Mycorrhizae increase auxin levels in root (possibly increasing root primordial development) while BF decreases root auxin (possibly increasing root elongation). BF reduces phenolic concentrations in the root. BF enhances mycorrhizae and root development, and results in increased tree seedling growth. 36 refs., 9 figs.

  2. Adsorption Isotherms of Boron in Soil: the effects of Sodium Adsorption Ratio (SAR, pH and Ionic strength

    Directory of Open Access Journals (Sweden)

    Mojtaba Moqbeli

    2017-03-01

    Full Text Available Introduction: Boron (B is an essential plant micronutrient whose soil availability is influenced by many soil factors.Understanding the processes controling activity of boron (B in the soil solution is important for soil fertility management. The reaction of adsorption and desorption of boron in soil determines the amount of boron that is available to plants. Adsorption–desorption processes play a major role on boron equilibrium concentration and therefore on its bio-availability. Ionic strength, pH and ionic composition in exchangeable phase are among themajor factors affecting B adsorption reactions.Reducedadsorption of boron at high pH is because of a surface potential decrease onminerals with pH-dependent charge. Ionic strength has also a considerable effect on B adsorption.Several studies have been performed inthe adsorption of boron and the effect of factors such as ionicstrength and cations has been understudied, however, the effect of sodium adsorption ratio and itsinteraction with the ionic strength on boron adsorption behavior has not been reported. In thisstudy, the adsorption isotherms of boron in the soils affected by the combined effects of ionic strengthand sodium adsorption ratio were investigated. Materials and Methods: In order to assess the effects of ionic strength (IS and Sodium Adsorption Ratio (SAR on availability of B, the adsorption of B was investigated in a calcareous soil that hadlow levels of electrical conductivity, sodium adsorption ratio and available P. For this purpose, 5 g soil wasequilibrated with 20 mL of B solution (0, 2, 5, 8, 10, 15, 20 mg L-1 in 0.02, 0.06 and 0.12 M background solutions (prepared by NaC1,CaC12.2H2O, MgCl2.6H2O, at two SAR levels (20 and 100.The reaction temperature was 25◦C. The suspension was centrifuged, filtered, and a sample was removed and B was determined by Azomethine-H spectrophotometric method (at a wavelength of 420 nm. B adsorption in Soil was obtained by subtracting B in

  3. Real-time boronization in PBX-M using erosion of solid boronized targets

    International Nuclear Information System (INIS)

    Kugel, H.W.; Timberlake, J.; Bell, R.

    1994-01-01

    Thirty one real-time boronizations were applied to PBX-M using the plasma ablation of solid target probes. More than 17 g of boron was deposited in PBX-M using this technique. The probes were positioned at the edge plasma to optimize ablation and minimize spallation. Auger depth profile analysis of poloidal and toroidal deposition sample coupon arrays indicate that boron was transported by the plasma around the torus and deep into the divertors. During discharges with continuous real-time boronization, low-Z and high-Z impurities decreased rapidly as plasma surfaces were covered during the first 20--30 discharges. After boronization, a short-term improvement in plasma conditions persisted prior to significant boron erosion from plasma surfaces, and a longer term, but less significant, improvement persisted as boron farther from the edge continued gettering. Real-time solid target boronization has been found to be very effective for accelerating conditioning to new regimes and maintaining high performance plasma conditions

  4. Proceedings of workshop on 'boron science and boron neutron capture therapy'

    Energy Technology Data Exchange (ETDEWEB)

    Kitaoka, Y. [ed.

    1998-12-01

    This volume contains the abstracts and programs of the 8th (1996), 9th (1997) and 10th (1998) of the workshop on 'the Boron Science and Boron Neutron Capture Therapy' and the recent progress reports especially subscribed. The 11 of the presented papers are indexed individually. (J.P.N.)

  5. Enrichment situation outside the United States

    International Nuclear Information System (INIS)

    Anon.

    1979-01-01

    Different enrichment technologies are briefly characterized which include gaseous diffusion, which is presently the production mainstay of the United States and France; the gaseous centrifuge which is the production plant for Urenco and the technology for future United States enrichment expansion; the aero-dynamic processes which include the jet nozzle (also known as the Becker process) and the fixed-wall centrifuge (also known as the Helikon process); chemical processes; laser isotope separation processes (also referred to in the literature as LIS); and plasma technology

  6. Ceramic silicon-boron-carbon fibers from organic silicon-boron-polymers

    Science.gov (United States)

    Riccitiello, Salvatore R. (Inventor); Hsu, Ming-Ta S. (Inventor); Chen, Timothy S. (Inventor)

    1993-01-01

    Novel high strength ceramic fibers derived from boron, silicon, and carbon organic precursor polymers are discussed. The ceramic fibers are thermally stable up to and beyond 1200 C in air. The method of preparation of the boron-silicon-carbon fibers from a low oxygen content organosilicon boron precursor polymer of the general formula Si(R2)BR(sup 1) includes melt-spinning, crosslinking, and pyrolysis. Specifically, the crosslinked (or cured) precursor organic polymer fibers do not melt or deform during pyrolysis to form the silicon-boron-carbon ceramic fiber. These novel silicon-boron-carbon ceramic fibers are useful in high temperature applications because they retain tensile and other properties up to 1200 C, from 1200 to 1300 C, and in some cases higher than 1300 C.

  7. Enhanced diffusion of boron by oxygen precipitation in heavily boron-doped silicon

    Science.gov (United States)

    Torigoe, Kazuhisa; Ono, Toshiaki

    2017-06-01

    The enhanced diffusion of boron has been investigated by analyzing out-diffusion profiles in the vicinity of the interface between a lightly boron-doped silicon epitaxial layer and a heavily boron-doped silicon substrate with a resistivity of 8.2 mΩ cm and an oxide precipitate (O.P.) density of 108-1010 cm-3. It is found that the boron diffusion during annealing at 850-1000 °C is enhanced with the increase of the oxide precipitate density. On the basis of a model for boron diffusion mediated by silicon self-interstitials, we reveal that the enhanced diffusion is attributed to self-interstitials supersaturated as a result of the emission from oxide precipitates and the absorption by punched-out dislocations. In addition, the temperature dependence of the fraction of the self-interstitial emission obtained analyzing the diffusion enhancement well explains the morphology changes of oxide precipitates reported in literature.

  8. Boron-containing thioureas for neutron capture therapy

    International Nuclear Information System (INIS)

    Ketz, H.

    1993-01-01

    Melanin is produced in large amounts in malignant melanotic melanomas. Because thiourea compounds are covalently incorporated into melanin during its biosynthesis, the preparation of boronated thiourea-derivatives is of particular interest for the BNCT (Boron Neutron Capture Therapy). Accumulation of boron in tumors by means of boronated thiourea-derivatives may therefore provide levels of 10 B which are useful for BNCT. In BNCT the tumor containing the boron compound is irradiated with epithermal neutrons to generate He- and Li-nuclei from the 10 B which can then destroy the tumor cells. Because of the short ranges of these particles (approximately one cell diameter) the damage will be almost exclusively confined to the tumor leaving normal tissue unharmed. High accumulation of 2-mercapto-1-methylimidazole (methimazole) in melanotic melanomas has been described in the literature. Boronated derivatives of methimazole were therefore synthesized. Boron was in the form of a boronic acid, a nido-carbonate and a mercaptoundeca hydro-closo-dodecaborate (BSH). The synthesis of the boron cluster derivatives of methimazole (nido-carborate- and BSH-derivatives) with 9 resp. 12 boron atoms in the molecule were expected to achieve higher concentrations of boron in the tumor than in the case of the boronic acid compound with its single boron atom. (orig.) [de

  9. Plant sterol enriched functional food and atherosclerosis.

    Science.gov (United States)

    Köhler, Jürgen; Teupser, Daniel; Elsässer, Albrecht; Weingärtner, Oliver

    2017-06-01

    Hypercholesterolaemia is a major cardiovascular risk factor. A healthy diet and a healthy lifestyle reduces cardiovascular risk. 'Functional foods' supplemented with phytosterols are recommended for the management of hypercholesterolaemia and have become a widely used non-prescription approach to lower plasma cholesterol levels. Two billion euros are spent world-wide each year on various functional foods, which have regulator-approved health claims for the management of elevated cholesterol levels. While international societies, such as the European Atherosclerosis Society or the National Heart Foundation in Australia, still advise phytosterols as an additional dietary option in the management of hypercholesterolaemia, recently released guidelines such as those from the National Institute of Health and Clinical Excellence in the United Kingdom are more critical of food supplementation with phytosterols and draw attention to significant safety issues. This review challenges whether an intervention with phytosterol supplements is beneficial. We summarize the current evidence from genetic diseases, genetic association studies, clinical trial data and data from animal studies. This article is part of a themed section on Principles of Pharmacological Research of Nutraceuticals. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v174.11/issuetoc. © 2017 The British Pharmacological Society.

  10. The Effects of Organic Wastes on Soil and Cotton Quality with respect to the Risk of Boron and Heavy Metal Pollution

    OpenAIRE

    Seçer, Müzeyyen; Elmaci, Ömer Lütfü; Ceylan, Şafak

    2016-01-01

    The effects on soil and cotton quality of organic wastes from medicinal and aromatic plant factories were investigated with regard to the risks of boron and heavy metal pollution. Oily cumin, oregano, oilless oregano wastes, and mineral fertilizers were applied to cotton in two field experiments performed in the years 2003 and 2006. The Pb content of the soil differed significantly in the 2003 experiment and oregano wastes had significantly decreasing effect. Boron of soil to which oily cumin...

  11. Laser and gas centrifuge enrichment

    Science.gov (United States)

    Heinonen, Olli

    2014-05-01

    Principles of uranium isotope enrichment using various laser and gas centrifuge techniques are briefly discussed. Examples on production of high enriched uranium are given. Concerns regarding the possibility of using low end technologies to produce weapons grade uranium are explained. Based on current assessments commercial enrichment services are able to cover the global needs of enriched uranium in the foreseeable future.

  12. Oxygen enrichment incineration

    International Nuclear Information System (INIS)

    Kim, Jeong Guk; Yang, Hee Chul; Park, Geun Il; Kim, Joon Hyung

    2000-10-01

    Oxygen enriched combustion technology has recently been used in waste incineration. To apply the oxygen enrichment on alpha-bearing waste incineration, which is being developed, a state-of-an-art review has been performed. The use of oxygen or oxygen-enriched air instead of air in incineration would result in increase of combustion efficiency and capacity, and reduction of off-gas product. Especially, the off-gas could be reduced below a quarter, which might reduce off-gas treatment facilities, and also increase an efficiency of off-gas treatment. However, the use of oxygen might also lead to local overheating and high nitrogen oxides (NOx) formation. To overcome these problems, an application of low NOx oxy-fuel burner and recycling of a part of off-gas to combustion chamber have been suggested

  13. Oxygen enrichment incineration

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jeong Guk; Yang, Hee Chul; Park, Geun Il; Kim, Joon Hyung

    2000-10-01

    Oxygen enriched combustion technology has recently been used in waste incineration. To apply the oxygen enrichment on alpha-bearing waste incineration, which is being developed, a state-of-an-art review has been performed. The use of oxygen or oxygen-enriched air instead of air in incineration would result in increase of combustion efficiency and capacity, and reduction of off-gas product. Especially, the off-gas could be reduced below a quarter, which might reduce off-gas treatment facilities, and also increase an efficiency of off-gas treatment. However, the use of oxygen might also lead to local overheating and high nitrogen oxides (NOx) formation. To overcome these problems, an application of low NOx oxy-fuel burner and recycling of a part of off-gas to combustion chamber have been suggested.

  14. Determination of boron content and isotopic composition in gypsum by inductively coupled plasma optical emission spectroscopy and positive thermal ionization mass spectrometry using phase transformation.

    Science.gov (United States)

    Ma, Yun-Qi; Peng, Zhang-Kuang; Yang, Jian; Xiao, Ying-Kai; Zhang, Yan-Ling

    2017-12-01

    As a stable isotope, boron plays an important role in hydrogeology, environmental geochemistry, ore deposit geochemistry and marine paleoclimatology. However, there is no report of boron isotopic composition in gypsum. This is mainly confined to complete dissolution of Gypsum by water or acid. In this study, gypsum was converted to calcium carbonate (CaCO 3 ) with ammonium bicarbonate(NH 4 HCO 3 ) by two steps at 50°C. In every step, the mass ratio of NH 4 HCO 3 /CaSO 4 ·2H 2 O was twice, and conversion rate reached more than 98%. Converted CaCO 3 was totally dissolved with hydrochloric acid (the dissolution rate was over 99%). In order to overcome the difficulties of the matrix interference and the detection limit of Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES), we use Amberlite IRA 743 resin to purify and enrichment the boron at first, then eluting boron from the resin with 10mL 0.1mol/L hydrochloric acid at 75°C. The boron isotopic composition of natural gypsum samples was determined using positive thermal ionization mass spectrometry (P-TIMS). The boron isotopic composition of gypsum may be an excellent indicator for the formation environment. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Development of an on-line isotope dilution laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) method for determination of boron in silicon wafers.

    Science.gov (United States)

    Yang, Chao-Kai; Chi, Po-Hsiang; Lin, Yong-Chine; Sun, Yuh-Chang; Yang, Mo-Hsiung

    2010-01-15

    A method has been developed based on an on-line isotope dilution technique couple with laser ablation/inductively coupled plasma mass spectrometry (LA-ICP-MS), for the determination of boron in p-type silicon wafers. The laser-ablated sample aerosol was mixed on-line with an enriched boron aerosol supplied continuously using a conventional nebulization system. Upon mixing the two aerosol streams, the isotope ratio of boron changed rapidly and was then recorded by the ICP-MS system for subsequent quantification based on the isotope dilution principle. As an on-line solid analysis method, this system accurately quantifies boron concentrations in silicon wafers without the need for an internal or external solid reference standard material. Using this on-line isotope dilution technique, the limit of detection for boron in silicon wafers is 2.8x10(15)atomscm(-3). The analytical results obtained using this on-line methodology agree well with those obtained using wet chemical digestion methods for the analysis of p-type silicon wafers containing boron concentrations ranging from 1.0x10(16) to 9.6x10(18)atomscm(-3).

  16. Uranium Conversion & Enrichment

    Energy Technology Data Exchange (ETDEWEB)

    Karpius, Peter Joseph [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-02-06

    The isotopes of uranium that are found in nature, and hence in ‘fresh’ Yellowcake’, are not in relative proportions that are suitable for power or weapons applications. The goal of conversion then is to transform the U3O8 yellowcake into UF6. Conversion and enrichment of uranium is usually required to obtain material with enough 235U to be usable as fuel in a reactor or weapon. The cost, size, and complexity of practical conversion and enrichment facilities aid in nonproliferation by design.

  17. Advanced uranium enrichment processes

    International Nuclear Information System (INIS)

    Clerc, M.; Plurien, P.

    1986-01-01

    Three advanced Uranium enrichment processes are dealt with in the report: AVLIS (Atomic Vapour LASER Isotope Separation), MLIS (Molecular LASER Isotope Separation) and PSP (Plasma Separation Process). The description of the physical and technical features of the processes constitutes a major part of the report. If further presents comparisons with existing industrially used enrichment technologies, gives information on actual development programmes and budgets and ends with a chapter on perspectives and conclusions. An extensive bibliography of the relevant open literature is added to the different subjects discussed. The report was drawn up by the nuclear research Centre (CEA) Saclay on behalf of the Commission of the European Communities

  18. Uranium enrichment by diffusion process

    International Nuclear Information System (INIS)

    Petit, J.F.

    1977-01-01

    A brief history of the process is given, and existing facilities are described, and the possibility of this process meeting the needs for enriched uranium in the future is discussed. It is concluded that, since other separation techniques have not yet been proven to be competitive, the gaseous diffusion process must be relied on to meet most of these needs. However, because of the high energy consumption required by this process, attempts to improve the technology must be continued. Is the gaseous diffusion process able to meet this challenge. Considering the technical viewpoint, there is no doubt about it. From the economical standpoint, this process is mainly characterized by an important energy consumption and the necessity to build large plants, thus leading to an important investment, at least for the first plant. Other processes have been developed with a view to reduce both the energy and capital needs. However, in spite of continuous studies and technological progress no process has yet been proven to be competitive. Large increments in capacities are still expected to come from the gaseous diffusion and several projects taking into acount the improvements in the flexibility, automatization, reliability and a reduced investment, will be analysed. Coupling of new facilities to existing plants has already proven to be of great interest. This situation explains why further investigations concerning the gaseous diffusion are being carried on, together with the study of new processes [fr

  19. 15th International Conference on Boron Chemistry (IMEBORON XV)

    Czech Academy of Sciences Publication Activity Database

    Grüner, Bohumír; Štíbr, Bohumil

    2015-01-01

    Roč. 87, č. 2 (2015), s. 121 ISSN 0033-4545 Institutional support: RVO:61388980 Keywords : boranes * boron * boron materials * carboranes * IMEBORON XV * medicinal chemistry Subject RIV: CA - Inorganic Chemistry

  20. Removal of boron from aqueous solution using cryptocrystalline magnesite

    CSIR Research Space (South Africa)

    Masindi, Vhahangwele

    2016-05-01

    Full Text Available The present study aimed to evaluate the efficiency of using cryptocrystalline magnesite to remove boron ions from aqueous systems. Batch experimental protocols were used to evaluate the adsorption capacity of magnesite for boron. Parameters...