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Sample records for mg dunn rl

  1. Psychometric Properties of Dunn\\'s Sensory Profile School Companion

    Directory of Open Access Journals (Sweden)

    Guita Movallali

    2017-10-01

    Conclusion The results showed that Dunn's sensory profile has good reliability and validity. Dunn's sensory profile is a useful tool for assessing sensory processing patterns in school and kindergarten settings, and can be used by occupational therapists in clinical environments and by psychologists in educational environments. Information obtained from this profile can have diagnostic value and could also be used for the design of curriculum and classroom space.

  2. Obituary: Richard B. Dunn, 1927-2005

    Science.gov (United States)

    Keil, Stephen L.; Dooling, David

    2007-12-01

    Dr. Richard B. Dunn, astronomer emeritus at the National Solar Observatory, died of a heart attack on September 29, 2005. He was recognized as one of the foremost experimental solar physicists. His innovative designs for telescopes and instruments led to many important discoveries in solar physics. Born in Baltimore, Maryland, in 1927 and raised in Minneapolis, Minnesota, Dick's parents were Dr. Halbert L. Dunn and Katherine Brandner. Halbert (MD, Ph.D., F.A.P.H.A.) was an physician who became Chief of the National Office of Vital Statistics, Public Health Service. He published a paper "High Level Wellness for Man and Society" that became the founding paper of the field of wellness health care. After their divorce in 1942, Katherine moved to New York and became a social worker. Dick had two older brothers who died before him, Halbert (born in 1921, who became a civil engineer) and Robert (born in 1924, who became an architect). Dick earned a BS in mechanical engineering and an MS in astronomy at the University of Minnesota. At the end of World War II he served in the United States Army in Japan. For his master's degree, Dick undertook the design and construction of a Lyot-type birefringent filter for observations of solar prominences. This early work led to his acceptance at Harvard, where Professor Donald Menzel encouraged him to continue his work with the 15-inch Cambridge telescope. In 1951 he conducted part of his doctoral thesis work at the fledgling Sacramento Peak Observatory in southern New Mexico. The observatory director, Dr. John Evans, was impressed with Dick's outstanding instrumental talents and invited him to join as one of the first scientific staff members. During his first few years at Sac Peak, Dick developed two more birefringent filter systems including one with an integrated coronagraph. With this system, he produced the best prominence and spicule observations ever obtained. Dick's career was dedicated to obtaining solar observations of the

  3. Capparis Cleghornii Dunn, a species from Southern India (Capparaceae)

    NARCIS (Netherlands)

    Rao, Rolla S.; Raghavan, R. Sundara

    1964-01-01

    Among recent collections from the evergreen forests of Mysore State in southern India, material was found of Capparis cleghornii Dunn which had only been known from the original collection made by Cleghorn in 1846 and from a Stocks specimen from “Kanara”. Further scrutiny of fresh collections from

  4. Fractional-order RC and RL circuits

    KAUST Repository

    Radwan, Ahmed Gomaa

    2012-05-30

    This paper is a step forward to generalize the fundamentals of the conventional RC and RL circuits in fractional-order sense. The effect of fractional orders is the key factor for extra freedom, more flexibility, and novelty. The conditions for RC and RL circuits to act as pure imaginary impedances are derived, which are unrealizable in the conventional case. In addition, the sensitivity analyses of the magnitude and phase response with respect to all parameters showing the locations of these critical values are discussed. A qualitative revision for the fractional RC and RL circuits in the frequency domain is provided. Numerical and PSpice simulations are included to validate this study. © Springer Science+Business Media, LLC 2012.

  5. RL-1: a certified uranium reference ore

    International Nuclear Information System (INIS)

    Steger, H.F.; Bowman, W.S.

    1985-06-01

    A 145-kg sample of a uranium ore from Rabbit Lake, Saskatchewan, has been prepared as a compositional reference material. RL-1 was ground to minus 74 μm and mixed in one lot. Approximately one half of this ore was bottled in 100-g units, the remainder being stored in bulk. The homogeneity of RL-1 with respect to uranium and nickel was confirmed by neutron activation and X-ray fluorescence analytical techniques. In a 'free choice' analytical program, 13 laboratories contributed results for one or more of uranium, nickel and arsenic in one bottle of RL-1. Based on a statistical analysis of the data, the following recommended values were assigned: U, 0.201%; Ni, 185 μg/g; and As, 19.6 μg/g

  6. Adaptation of Dunn Solar Telescope for Jovian Doppler spectro imaging

    Science.gov (United States)

    Underwood, Thomas A.; Voelz, David; Schmider, François-Xavier; Jackiewicz, Jason; Dejonghe, Julien; Bresson, Yves; Hull, Robert; Goncalves, Ivan; Gualme, Patrick; Morand, Frédéric; Preis, Olivier

    2017-09-01

    This paper describes instrumentation used to adapt the Dunn Solar Telescope (DST) located on Sacramento Peak in Sunspot, NM for observations using the Doppler Spectro Imager (DSI). The DSI is based on a Mach-Zehnder interferometer and measures the Doppler shift of solar lines allowing for the study of atmospheric dynamics of giant planets and the detection of their acoustic oscillations. The instrumentation is being designed and built through a collaborative effort between a French team from the Observatoire de la Cote d'Azur (OCA) that designed the DSI and a US team at New Mexico State University (NMSU). There are four major components that couple the DSI to the DST: a guider/tracker, fast steering mirror (FSM), pupil stabilizer and transfer optics. The guider/tracker processes digital video to centroid-track the planet and outputs voltages to the DST's heliostat controls. The FSM removes wavefront tip/tilt components primarily due to turbulence and the pupil stabilizer removes any slow pupil "wander" introduced by the telescope's heliostat/turret arrangement. The light received at a science port of the DST is sent through the correction and stabilization components and into the DSI. The FSM and transfer optics designs are being provided by the OCA team and serve much the same functions as they do for other telescopes at which DSI observations have been conducted. The pupil stabilization and guider are new and are required to address characteristics of the DST.

  7. Genetic regulation of IL1RL1 methylation and IL1RL1-a protein levels in asthma.

    Science.gov (United States)

    Dijk, F Nicole; Xu, Chengjian; Melén, Erik; Carsin, Anne-Elie; Kumar, Asish; Nolte, Ilja M; Gruzieva, Olena; Pershagen, Goran; Grotenboer, Neomi S; Savenije, Olga E M; Antó, Josep Maria; Lavi, Iris; Dobaño, Carlota; Bousquet, Jean; van der Vlies, Pieter; van der Valk, Ralf J P; de Jongste, Johan C; Nawijn, Martijn C; Guerra, Stefano; Postma, Dirkje S; Koppelman, Gerard H

    2018-03-01

    Interleukin-1 receptor-like 1 ( IL1RL1 ) is an important asthma gene. (Epi)genetic regulation of IL1RL1 protein expression has not been established. We assessed the association between IL1RL1 single nucleotide polymorphisms (SNPs), IL1RL1 methylation and serum IL1RL1-a protein levels, and aimed to identify causal pathways in asthma.Associations of IL1RL1 SNPs with asthma were determined in the Dutch Asthma Genome-wide Association Study cohort and three European birth cohorts, BAMSE (Children/Barn, Allergy, Milieu, Stockholm, an Epidemiological survey), INMA (Infancia y Medio Ambiente) and PIAMA (Prevention and Incidence of Asthma and Mite Allergy), participating in the Mechanisms of the Development of Allergy study. We performed blood DNA IL1RL1 methylation quantitative trait locus (QTL) analysis (n=496) and (epi)genome-wide protein QTL analysis on serum IL1RL1-a levels (n=1462). We investigated the association of IL1RL1 CpG methylation with asthma (n=632) and IL1RL1-a levels (n=548), with subsequent causal inference testing. Finally, we determined the association of IL1RL1-a levels with asthma and its clinical characteristics (n=1101). IL1RL1 asthma-risk SNPs strongly associated with IL1RL1 methylation (rs1420101; p=3.7×10 -16 ) and serum IL1RL1-a levels (p=2.8×10 -56 ). IL1RL1 methylation was not associated with asthma or IL1RL1-a levels. IL1RL1-a levels negatively correlated with blood eosinophil counts, whereas there was no association between IL1RL1-a levels and asthma.In conclusion, asthma-associated IL1RL1 SNPs strongly regulate IL1RL1 methylation and serum IL1RL1-a levels, yet neither these IL1RL1- methylation CpG sites nor IL1RL1-a levels are associated with asthma. Copyright ©ERS 2018.

  8. Promoting Writing among Psychology Students and Faculty: An Interview with Dana S. Dunn

    Science.gov (United States)

    Goddard, Perilou

    2002-01-01

    Perilou Goddard is a professor of psychology at Northern Kentucky University (NKU), where she teaches introductory and abnormal psychology as well as courses in writing in psychology and drug policy. She was chosen as NKU's outstanding professor in 1999. Dana S. Dunn is a professor of psychology and former chair of the Department of Psychology at…

  9. After Higgins and Dunne: Imagining School Teaching as a Multi-Practice Activity

    Science.gov (United States)

    Davies, Richard

    2013-01-01

    There remains a concern in philosophy of education circles to assert that teaching is a social practice. Its initiation occurs in a conversation between Alasdair MacIntyre and Joe Dunne which inspired a Special Issue of the "Journal of Philosophy of Education." This has been recently utilised in a further Special Issue by Chris Higgins.…

  10. Styrene maleic acid-encapsulated RL71 micelles suppress tumor growth in a murine xenograft model of triple negative breast cancer.

    Science.gov (United States)

    Martey, Orleans; Nimick, Mhairi; Taurin, Sebastien; Sundararajan, Vignesh; Greish, Khaled; Rosengren, Rhonda J

    2017-01-01

    Patients with triple negative breast cancer have a poor prognosis due in part to the lack of targeted therapies. In the search for novel drugs, our laboratory has developed a second-generation curcumin derivative, 3,5-bis(3,4,5-trimethoxybenzylidene)-1-methylpiperidine-4-one (RL71), that exhibits potent in vitro cytotoxicity. To improve the clinical potential of this drug, we have encapsulated it in styrene maleic acid (SMA) micelles. SMA-RL71 showed improved biodistribution, and drug accumulation in the tumor increased 16-fold compared to control. SMA-RL71 (10 mg/kg, intravenously, two times a week for 2 weeks) also significantly suppressed tumor growth compared to control in a xenograft model of triple negative breast cancer. Free RL71 was unable to alter tumor growth. Tumors from SMA-RL71-treated mice showed a decrease in angiogenesis and an increase in apoptosis. The drug treatment also modulated various cell signaling proteins including the epidermal growth factor receptor, with the mechanisms for tumor suppression consistent with previous work with RL71 in vitro. The nanoformulation was also nontoxic as shown by normal levels of plasma markers for liver and kidney injury following weekly administration of SMA-RL71 (10 mg/kg) for 90 days. Thus, we report clinical potential following encapsulation of a novel curcumin derivative, RL71, in SMA micelles.

  11. DOE-RL Integrated Safety Management System Description

    International Nuclear Information System (INIS)

    SHOOP, D.S.

    2000-01-01

    The purpose of this Integrated Safety Management System Description (ISMSD) is to describe the U.S. Department of Energy (DOE), Richland Operations Office (RL) ISMS as implemented through the RL Integrated Management System (RIMS). This ISMSD does not impose additional requirements but rather provides an overview describing how various parts of the ISMS fit together. Specific requirements for each of the core functions and guiding principles are established in other implementing processes, procedures, and program descriptions that comprise RIMS. RL is organized to conduct work through operating contracts; therefore, it is extremely difficult to provide an adequate ISMS description that only addresses RL functions. Of necessity, this ISMSD contains some information on contractor processes and procedures which then require RL approval or oversight. This ISMSD does not purport to contain a full description of the contractors' ISM System Descriptions

  12. DOE-RL Integrated Safety Management System Description

    CERN Document Server

    Shoop, D S

    2000-01-01

    The purpose of this Integrated Safety Management System Description (ISMSD) is to describe the U.S. Department of Energy (DOE), Richland Operations Office (RL) ISMS as implemented through the RL Integrated Management System (RIMS). This ISMSD does not impose additional requirements but rather provides an overview describing how various parts of the ISMS fit together. Specific requirements for each of the core functions and guiding principles are established in other implementing processes, procedures, and program descriptions that comprise RIMS. RL is organized to conduct work through operating contracts; therefore, it is extremely difficult to provide an adequate ISMS description that only addresses RL functions. Of necessity, this ISMSD contains some information on contractor processes and procedures which then require RL approval or oversight. This ISMSD does not purport to contain a full description of the contractors' ISM System Descriptions.

  13. Genetic regulation ofmethylation and IL1RL1-a protein levels in asthma

    NARCIS (Netherlands)

    Dijk, F Nicole; Xu, Chengjian; Melén, Erik; Carsin, Anne-Elie; Kumar, Asish; Nolte, Ilja M; Gruzieva, Olena; Pershagen, Goran; Grotenboer, Neomi S; Savenije, Olga E M; Antó, Josep Maria; Lavi, Iris; Dobaño, Carlota; Bousquet, Jean; van der Vlies, Pieter; van der Valk, Ralf J P; de Jongste, Johan C; Nawijn, Martijn C; Guerra, Stefano; Postma, Dirkje S; Koppelman, Gerard H

    2018-01-01

    Interleukin-1 receptor-like 1 (IL1RL1) is an important asthma gene. (Epi)genetic regulation ofIL1RL1protein expression has not been established. We assessed the association betweenIL1RL1single nucleotide polymorphisms (SNPs),IL1RL1methylation and serum IL1RL1-a protein levels, and aimed to identify

  14. Bender-Dunne Orthogonal Polynomials, Quasi-Exact Solvability and Asymptotic Iteration Method for Rabi Hamiltonian

    International Nuclear Information System (INIS)

    Yahiaoui, S.-A.; Bentaiba, M.

    2011-01-01

    We present a method for obtaining the quasi-exact solutions of the Rabi Hamiltonian in the framework of the asymptotic iteration method (AIM). The energy eigenvalues, the eigenfunctions and the associated Bender-Dunne orthogonal polynomials are deduced. We show (i) that orthogonal polynomials are generated from the upper limit (i.e., truncation limit) of polynomial solutions deduced from AIM, and (ii) prove to have nonpositive norm. (authors)

  15. Reduced Latency in the Metastatic Niche Contributes to the More Aggressive Phenotype of LM8 Compared to Dunn Osteosarcoma Cells

    Directory of Open Access Journals (Sweden)

    Matthias J. E. Arlt

    2013-01-01

    Full Text Available Metastasis is the major cause of death of osteosarcoma patients and its diagnosis remains difficult. In preclinical studies, however, forced expression of reporter genes in osteosarcoma cells has remarkably improved the detection of micrometastases and, consequently, the quality of the studies. We recently showed that Dunn cells equipped with a lacZ reporter gene disseminated from subcutaneous primary tumors as frequently as their highly metastatic subline LM8, but only LM8 cells grew to macrometastases. In the present time-course study, tail-vein-injected Dunn and LM8 cells settled within 24 h at the same frequency in the lung, liver, and kidney of mice. Furthermore, Dunn cells also grew to macrometastases, but, compared to LM8, with a delay of two weeks in lung and one week in liver and kidney tissue, consistent with prolonged survival of the mice. Dunn- and LM8-cell-derived ovary and spine metastases occurred less frequently. In vitro, Dunn cells showed less invasiveness and stronger contact inhibition and intercellular adhesion than LM8 cells and several cancer- and dormancy-related genes were differentially expressed. In conclusion, Dunn cells, compared to LM8, have a similar capability but a longer latency to form macrometastases and provide an interesting new experimental system to study tumor cell dormancy.

  16. Vacuum-field solutions of Ross and Sen-Dunn theories of gravitation

    International Nuclear Information System (INIS)

    Krori, K.D.; Nandy, D.

    1978-01-01

    Vacuum-field solutions of Ross (Phys. Rev.; D5:284 (1972)) and Sen-Dunn (J. Math. Phys.; 12:578 (1971)) theories of gravitation have been obtained with the aid of a Friedmann-type metric. Non-static solutions are found showing that the Birkhoff theorem holds for neither theory. It has been observed that the two theories have a limited scope for vacuum solution as against the Brans-Dicke theory. Mach's principle, however, holds for both the theories. (author)

  17. Status of CSR RL06 GRACE reprocessing and preliminary results

    Science.gov (United States)

    Save, H.

    2017-12-01

    The GRACE project plans to re-processes the GRACE mission data in order to be consistent with the first gravity products released by the GRACE-FO project. The RL06 reprocessing will harmonize the GRACE time-series with the first release of GRACE-FO. This paper catalogues the changes in the upcoming RL06 release and discusses the quality improvements as compared to the current RL05 release. The processing and parameterization changes as compared to the current release are also discussed. This paper discusses the evolution of the quality of the GRACE solutions and characterize the errors over the past few years. The possible challenges associated with connecting the GRACE time series with that from GRACE-FO are also discussed.

  18. RL5SORT/RL5PLOT. A graphite package for the JRC-Ispra IBM version of RELAP5/MOD1

    International Nuclear Information System (INIS)

    Kolar, W.; Brewka, W.

    1984-01-01

    The present report describes the programs RL5SORT and RL5PLOT, their implementation and ''how to use''. Both programs base on the IBM version of RELAP5 as developed at JRC-ISPRA. RL5SORT creates from the output file (restart plot file) of a RELAP5 calculation data files, which serve as input data base for the program RL5PLOT. RL5PLOT retrieves the previous stored data records (minor edit quantities of RELAP5), allows arithmetic operations with the retrieved data and enables a print or graphic output on the terminal screen of a TEKTRONIX graphic terminal. A set of commands, incorporated in the program RL5PLOT, facilitates the user's work. Program RL5SORT has been developed as a batch program, while RL5PLOT has been conceived for interactive working mode

  19. Styrene maleic acid-encapsulated RL71 micelles suppress tumor growth in a murine xenograft model of triple negative breast cancer

    Directory of Open Access Journals (Sweden)

    Martey O

    2017-10-01

    Full Text Available Orleans Martey,1 Mhairi Nimick,1 Sebastien Taurin,1 Vignesh Sundararajan,1 Khaled Greish,2 Rhonda J Rosengren1 1Department of Pharmacology and Toxicology, University of Otago, Dunedin, New Zealand; 2Department of Molecular Medicine, College of Medicine and Medical Sciences, Arabian Gulf University, Manama, Kingdom of Bahrain Abstract: Patients with triple negative breast cancer have a poor prognosis due in part to the lack of targeted therapies. In the search for novel drugs, our laboratory has developed a second-generation curcumin derivative, 3,5-bis(3,4,5-trimethoxybenzylidene-1-methylpiperidine-4-one (RL71, that exhibits potent in vitro cytotoxicity. To improve the clinical potential of this drug, we have encapsulated it in styrene maleic acid (SMA micelles. SMA-RL71 showed improved biodistribution, and drug accumulation in the tumor increased 16-fold compared to control. SMA-RL71 (10 mg/kg, intravenously, two times a week for 2 weeks also significantly suppressed tumor growth compared to control in a xenograft model of triple negative breast cancer. Free RL71 was unable to alter tumor growth. Tumors from SMA-RL71-treated mice showed a decrease in angiogenesis and an increase in apoptosis. The drug treatment also modulated various cell signaling proteins including the epidermal growth factor receptor, with the mechanisms for tumor suppression consistent with previous work with RL71 in vitro. The nanoformulation was also nontoxic as shown by normal levels of plasma markers for liver and kidney injury following weekly administration of SMA-RL71 (10 mg/kg for 90 days. Thus, we report clinical potential following encapsulation of a novel curcumin derivative, RL71, in SMA micelles. Keywords: curcumin derivatives, nanomedicine, EGFR, biodistribution

  20. Biotreatment of anthraquinone dye Drimarene Blue K 2 RL | Siddiqui ...

    African Journals Online (AJOL)

    Drimarene Blue (Db) K2RL is a reactive anthraquinone dye, used extensively in textile industry, due to poor adsorbability to textile fiber; it has a higher exhaustion rate in wastewater. The dye is toxic, carcinogenic, mutagenic and resistant to degradation. Decolorization of this dye was studied in two different systems.

  1. Absence of hypoxanthine:guanine phosphoribosyltransferase activity in murine Dunn osteosarcoma

    International Nuclear Information System (INIS)

    Abelson, H.T.; Gorka, C.

    1983-01-01

    The transplantable murine Dunn osteosarcoma has no detectable hypoxanthine:guanine phosphoribosyltransferase (EC 2.4.2.8) activity. This was established from the tumors directly and from tissue culture cell lines derived from the tumor using a variety of assays: e.g., no [3H]hypoxanthine uptake into tumor or tissue culture cells, no conversion of [3H]hypoxanthine to [3H]IMP by cell extracts from tumors or tissue culture cells, no growth of tissue culture cells in hypoxanthine:aminopterin:thymidine medium, and normal growth of these cells in 10 microM 6-mercaptopurine. Ten human osteosarcomas have been assayed, and two have no apparent hypoxanthine:guanine phosphoribosyltransferase enzyme activity. After high-dose methotrexate treatment in vivo, murine tumors could be selectively killed and normal tissues could be spared by using a rescue regimen of hypoxanthine-thymidine-allopurinol

  2. Calibration of piezoelectric RL shunts with explicit residual mode correction

    DEFF Research Database (Denmark)

    Høgsberg, Jan Becker; Krenk, Steen

    2017-01-01

    Piezoelectric RL (resistive-inductive) shunts are passive resonant devices used for damping of dominant vibration modes of a flexible structure and their efficiency relies on the precise calibration of the shunt components. In the present paper improved calibration accuracy is attained by an exte......Piezoelectric RL (resistive-inductive) shunts are passive resonant devices used for damping of dominant vibration modes of a flexible structure and their efficiency relies on the precise calibration of the shunt components. In the present paper improved calibration accuracy is attained...... by an extension of the local piezoelectric transducer displacement by two additional terms, representing the flexibility and inertia contributions from the residual vibration modes not directly addressed by the shunt damping. This results in an augmented dynamic model for the targeted resonant vibration mode...

  3. Progress towards CSR RL06 GRACE gravity solutions

    Science.gov (United States)

    Save, Himanshu

    2017-04-01

    The GRACE project plans to re-processes the GRACE mission data in order to be consistent with the first gravity products released by the GRACE-FO project. The next generation Release-06 (RL06) gravity products from GRACE will include the improvements in GRACE Level-1 data products, background gravity models and the processing methodology. This paper will outline the planned improvements for CSR - RL06 and discuss the preliminary results. This paper will discuss the evolution of the quality of the GRACE solutions, especially over the past few years. We will also discuss the possible challenges we may face in connecting/extending the measurements of mass fluxes from the GRACE era to the GRACE-FO era due quality of the GRACE solutions from recent years.

  4. 3D Laser Processing : The Renault Rl5

    Science.gov (United States)

    Rolland, Olivier C.; Meyer, Bernard D.

    1986-11-01

    The RL5, a five-axis robot, is designed to steer a powerful laser beam on 3 dimensional (3D) trajectories with a great accuracy. Cutting and welding with a CO2 laser beam, drilling with a YAG laser beam are some applications of this machine which can be integrated in a production line. Easy management and modifications of trajectories, obtained either in a teaching mode or by a CAD-CAM system, give the laser tool its main interest : flexibility.

  5. High-resolution CSR GRACE RL05 mascons

    Science.gov (United States)

    Save, Himanshu; Bettadpur, Srinivas; Tapley, Byron D.

    2016-10-01

    The determination of the gravity model for the Gravity Recovery and Climate Experiment (GRACE) is susceptible to modeling errors, measurement noise, and observability issues. The ill-posed GRACE estimation problem causes the unconstrained GRACE RL05 solutions to have north-south stripes. We discuss the development of global equal area mascon solutions to improve the GRACE gravity information for the study of Earth surface processes. These regularized mascon solutions are developed with a 1° resolution using Tikhonov regularization in a geodesic grid domain. These solutions are derived from GRACE information only, and no external model or data is used to inform the constraints. The regularization matrix is time variable and will not bias or attenuate future regional signals to some past statistics from GRACE or other models. The resulting Center for Space Research (CSR) mascon solutions have no stripe errors and capture all the signals observed by GRACE within the measurement noise level. The solutions are not tailored for specific applications and are global in nature. This study discusses the solution approach and compares the resulting solutions with postprocessed results from the RL05 spherical harmonic solutions and other global mascon solutions for studies of Arctic ice sheet processes, ocean bottom pressure variation, and land surface total water storage change. This suite of comparisons leads to the conclusion that the mascon solutions presented here are an enhanced representation of the RL05 GRACE solutions and provide accurate surface-based gridded information that can be used without further processing.

  6. Modified Weaver-Dunn Procedure Versus The Use of Semitendinosus Autogenous Tendon Graft for Acromioclavicular Joint Reconstruction.

    Science.gov (United States)

    Hegazy, Galal; Safwat, Hesham; Seddik, Mahmoud; Al-Shal, Ehab A; Al-Sebai, Ibrahim; Negm, Mohame

    2016-01-01

    The optimal operative method for acromioclavicular joint reconstruction remains controversial. The modified Weaver-Dunn method is one of the most popular methods. Anatomic reconstruction of coracoclavicular ligaments with autogenous tendon grafts, widely used in treating chronic acromioclavicular joint instability, reportedly diminishes pain, eliminates sequelae, and improves function as well as strength. To compare clinical and radiologic outcomes between a modified Weaver-Dunn procedure and an anatomic coracoclavicular ligaments reconstruction technique using autogenous semitendinosus tendon graft. Twenty patients (mean age, 39 years) with painful, chronic Rockwood type III acromioclavicular joint dislocations were subjected to surgical reconstruction. In ten patients, a modified Weaver-Dunn procedure was performed, in the other ten patients; autogenous semitendinosus tendon graft was used. The mean time between injury and the index procedure was 18 month (range from 9 - 28). Clinical evaluation was performed using the Oxford Shoulder Score and Nottingham Clavicle Score after a mean follow-up time of 27.8 months. Preoperative and postoperative radiographs were compared. In the Weaver-Dunn group the Oxford Shoulder Score improved from 25±4 to 40±2 points. While the Nottingham Clavicle Score increased from 48±7 to 84±11. In semitendinosus tendon graft group, the Oxford Shoulder Score improved from 25±3 points to 50±2 points and the Nottingham Clavicle Score from 48±8 points to 95±8, respectively. Acromioclavicular joint reconstruction using the semitendinosus tendon graft achieved better Oxford Shoulder Score and Nottingham Clavicle Score compared to the modified Weaver-Dunn procedure.

  7. Streptomyces castaneus sp. nov., a novel actinomycete isolated from the rhizosphere of Peucedanum praeruptorum Dunn.

    Science.gov (United States)

    Zhou, Shuyu; Li, Zhilei; Bai, Lu; Yan, Kai; Zhao, Junwei; Lu, Chang; Liu, Chongxi; Wang, Xiangjing; Xiang, Wensheng

    2017-01-01

    During an investigation of microbial diversity in medicinal herbs, a novel actinomycete, strain NEAU-QHHV11 T was isolated from the rhizosphere of Peucedanum praeruptorum Dunn collected from Xianglu Mountain in Heilongjiang Province, northeast China and characterized using a polyphasic approach. The organism was found to have typical characteristics of the genus Streptomyces. Phylogenetic analysis based on 16S rRNA gene sequence also indicated that strain NEAU-QHHV11 T belongs to the genus Streptomyces and was most closely related to Streptomyces graminilatus NBRC 108882 T (98.7 % sequence similarity) and Streptomyces turgidiscabies NBRC 16080 T (98.7 % sequence similarity). The results of DNA-DNA hybridization and some phenotypic characteristics indicated that strain NEAU-QHHV11 T could be distinguished from its close phylogenetic relatives. Thus, strain NEAU-QHHV11 T represents a novel species of the genus Streptomyces, for which the name Streptomyces castaneus sp. nov. is proposed. The type strain is NEAU-QHHV11 T (=CGMCC 4.7235 T  = DSM 100520 T ).

  8. Environmental Management Performance Report to DOE-RL June 2002

    International Nuclear Information System (INIS)

    EDER, D.M.

    2002-01-01

    The purpose of this report is to provide the Department of Energy Richland Operations Office (RL) a monthly summary of the Central Plateau Contractor's Environmental Management (EM) performance by Fluor Hanford (FH) and its subcontractors. Only current FH workscope responsibilities are described and other contractor/RL managed work is excluded. Please refer to other sections (BHI, PNNL) for other contractor information. Section A, Executive Summary, provides an executive level summary of the cost, schedule, and technical performance described in this report. It summarizes performance for the period covered, highlights areas worthy of management attention, and provides a forward look to some of the upcoming key performance activities as extracted from the contractor baseline. The remaining sections provide detailed performance data relative to each individual subproject (e.g., Plutonium Finishing Plant, Spent Nuclear Fuels, etc.), in support of Section A of the report. All information is updated as of the end of June 2002 unless otherwise noted. ''Stoplight'' boxes are used to indicate at a glance the condition of a particular safety area. Green boxes denote either (1) the data are stable at a level representing acceptable performance, or (2) an improving trend exists. Yellows denote the data are stable at a level from which improvement is needed. Red denotes a trend exists in a non-improving direction

  9. Total Saponin from Root of Actinidia valvata Dunn Inhibits Hepatoma 22 Growth and Metastasis In Vivo by Suppression Angiogenesis

    Directory of Open Access Journals (Sweden)

    Guo-Yin Zheng

    2012-01-01

    Full Text Available The root of Actinidia valvata dunn has been widely used in the treatment of hepatocellular carcinoma (HCC, proved to be beneficial for a longer and better life in China. In present work, total saponin from root of Actinidia valvata Dunn (TSAVD was extracted, and its effects on hepatoma H22-based mouse in vivo were observed. Primarily transplanted hypodermal hepatoma H22-based mice were used to observe TSAVD effect on tumor growth. The microvessel density (MVD, vascular endothelial growth factor (VEGF, basic fibroblast growth factor (bFGF are characterized factors of angiogenesis, which were compared between TSAVD-treated and control groups. Antimetastasis effect on experimental pulmonary metastasis hepatoma mice was also observed in the study. The results demonstrated that TSAVD can effectively inhibit HCC growth and metastasis in vivo, inhibit the formation of microvessel, downregulate expressions of VEGF and bFGF, and retrain angiogenesis of hepatoma 22 which could be one of the reasons.

  10. Cloning, functional characterization and catalytic mechanism of a bergaptol O-methyltransferase from Peucedanum praeruptorum Dunn

    Directory of Open Access Journals (Sweden)

    Yucheng eZhao

    2016-05-01

    Full Text Available Coumarins are main active components of Peucedanum praeruptorum Dunn. Among them, methoxylated coumarin compound, such as bergapten, xanthotoxin and isopimpinellin, has high officinal value and plays an important role in medicinal field. However, major issues associated with the biosynthesis mechanism of coumarins remain unsolved and no corresponding enzyme has been cloned from P. praeruptorum. In this study, a local BLASTN program was conducted to find the candidate genes from P. praeruptorum transcriptome database using the nucleotide sequence of Ammi majus bergaptol O-methyltransferase (AmBMT, GenBank accession No: AY443006 as a template. As a result, a 1335 bp full-length of cDNA sequence which contains an open reading frame of 1080 bp encoding a BMT polypeptide of 359 amino acids was obtained. The recombinant protein was functionally expressed in Escherichia coli and displayed an observed activity to bergaptol. In vitro experiments show that the protein has narrow substrate specificity for bergaptol. Expression profile indicated that the cloned gene had a higher expression level in roots and can be induced by methyl jasmonate (MeJA. Subcellular localization analysis showed that the BMT protein was located in cytoplasm in planta. Homology modeling and docking based site-directed mutagenesis have been employed to investigate the amino acid residues in BMT required for substrate binding and catalysis. Conservative amino acid substitutions at residue H264 affected BMT catalysis, whereas substitutions at residues F171, M175, D226 and L312 affected substrate binding. The systemic study summarized here will enlarge our knowledge on OMTs and provide useful information in investigating the coumarins biosynthesis mechanism in P. praeruptorum.

  11. IL1RL1 gene variants and nasopharyngeal IL1RL-a levels are associated with severe RSV bronchiolitis: a multicenter cohort study.

    Directory of Open Access Journals (Sweden)

    Tina E Faber

    Full Text Available Targets for intervention are required for respiratory syncytial virus (RSV bronchiolitis, a common disease during infancy for which no effective treatment exists. Clinical and genetic studies indicate that IL1RL1 plays an important role in the development and exacerbations of asthma. Human IL1RL1 encodes three isoforms, including soluble IL1RL1-a, that can influence IL33 signalling by modifying inflammatory responses to epithelial damage. We hypothesized that IL1RL1 gene variants and soluble IL1RL1-a are associated with severe RSV bronchiolitis.We studied the association between RSV and 3 selected IL1RL1 single-nucleotide polymorphisms rs1921622, rs11685480 or rs1420101 in 81 ventilated and 384 non-ventilated children under 1 year of age hospitalized with primary RSV bronchiolitis in comparison to 930 healthy controls. Severe RSV infection was defined by need for mechanical ventilation. Furthermore, we examined soluble IL1RL1-a concentration in nasopharyngeal aspirates from children hospitalized with primary RSV bronchiolitis. An association between SNP rs1921622 and disease severity was found at the allele and genotype level (p = 0.011 and p = 0.040, respectively. In hospitalized non-ventilated patients, RSV bronchiolitis was not associated with IL1RL1 genotypes. Median concentrations of soluble IL1RL1-a in nasopharyngeal aspirates were >20-fold higher in ventilated infants when compared to non-ventilated infants with RSV (median [and quartiles] 9,357 [936-15,528] pg/ml vs. 405 [112-1,193] pg/ml respectively; p<0.001.We found a genetic link between rs1921622 IL1RL1 polymorphism and disease severity in RSV bronchiolitis. The potential biological role of IL1RL1 in the pathogenesis of severe RSV bronchiolitis was further supported by high local concentrations of IL1RL1 in children with most severe disease. We speculate that IL1RL1a modifies epithelial damage mediated inflammatory responses during RSV bronchiolitis and thus may serve as a

  12. Reduction of characteristic RL time for fast, efficient magnetic levitation

    Directory of Open Access Journals (Sweden)

    Yuqing Li

    2017-09-01

    Full Text Available We demonstrate the reduction of characteristic time in resistor-inductor (RL circuit for fast, efficient magnetic levitation according to Kirchhoff’s circuit laws. The loading time is reduced by a factor of ∼4 when a high-power resistor is added in series with the coils. By using the controllable output voltage of power supply and voltage of feedback circuit, the loading time is further reduced by ∼ 3 times. The overshoot loading in advance of the scheduled magnetic field gradient is equivalent to continuously adding a resistor without heating. The magnetic field gradient with the reduced loading time is used to form the upward magnetic force against to the gravity of the cooled Cs atoms, and we obtain an effectively levitated loading of the Cs atoms to a crossed optical dipole trap.

  13. Up-regulatation of CYP3A expression through pregnent X receptor by praeruptorin D isolated from Peucedanum praeruptorum Dunn.

    Science.gov (United States)

    Huang, Ling; Huang, Min; Li, Yu-Hua; Li, Rui-Ming; Zeng, Yu; Kuang, Shao-Yi; Zhang, Li; Wang, Yi-Tao; Bi, Hui-Chang

    2013-07-09

    Qianhu, the dried roots of Peucedanum praeruptorum DUNN (Umbelliferae), is a well-known traditional Chinese medicinal herb which was officially listed in the Chinese Pharmacopoeia. Praeruptorin D (PD) is one of the major active constituents of Peucedanum praeruptorum Dunn (Qianhu). The Pregnane X receptor (PXR) is an orphan nuclear receptor and plays a pivotal role in the activation of human cytochrome P450 3A4 (CYP3A4) gene. The purpose of this study was to investigate the effect of PD on the PXR-mediated transactivation of CYP3A4, and thus to predict potential herb-drug interactions between PD, Qianhu, and the other co-administered drugs that metabolized by CYP3A4. The effect of PD on the Cyp3a11, mPXR mRNA expression in mice primary hepatocytes was measured using real-time PCR. The gene expression, protein expression, and catalytic activity of CYP3A4 in the LS174T cells after transfected with PXR expression plasmids were determined by real-time PCR, Western blot analysis, and LC-MS/MS based CYP3A4 substrate assay. The results revealed that the level of Cyp3a11 gene expression in mice primary hepatocytes was significantly increased by PD, but PD cannot induce the mPXR gene expression. On the other hand, CYP3A4 mRNA, protein expression and functional activity in PXR-over-expression LS174T cells were significantly increased by PD through PXR-mediated pathway; conversely, no significant change was found in the untransfected cells. These findings suggest that PD can significantly up-regulate CYP3A4 expression and activity via the PXR-mediated pathway and this should be taken into consideration to predict any potential herb-drug interactions when PD and Peucedanum praeruptorum Dunn are co-administered with other drugs. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  14. Environmental Management Performance Report to DOE-RL December 2001

    International Nuclear Information System (INIS)

    EDER, D.M.

    2001-01-01

    The purpose of this report is to provide the Department of Energy Richland Operations Office (RL) a monthly summary of the Central Plateau Contractor's Environmental Management (EM) performance by Fluor Hanford (FH) and its subcontractors. Only current FH workscope responsibilities are described. Please refer to other sections (BHI, PNNL) for other contractor information. Section A, Executive Summary, provides an executive level summary of the cost, schedule, and technical performance described in this report. It summarizes performance for the period covered, highlights areas worthy of management attention, and provides a forward look to some of the upcoming key performance activities as extracted from the contractor baseline. The remaining sections provide detailed performance data relative to each individual subproject (e.g., Plutonium Finishing Plant, Spent Nuclear Fuels, etc.), in support of Section A of the report. All information is updated as of October 31, 2001 unless otherwise noted. ''Stoplight'' boxes are used to indicate at a glance the condition of a particular safety area. Green boxes denote either (1) the data are stable at a level representing ''acceptable'' performance, or (2) an improving trend exists. Yellows denote the data are stable at a level from which improvement is needed. Red denotes a trend exists in a non-improving direction

  15. Environmental Management Performance Report to DOE-RL September 2001

    International Nuclear Information System (INIS)

    EDER, D.M.

    2001-01-01

    The purpose of this report is to provide the Department of Energy Richland Operations Office (RL) a monthly summary of the Central Plateau Contractor's Environmental Management (EM) performance by Fluor Hanford (FH) and its subcontractors. Section A, Executive Summary, provides an executive level summary of the cost, schedule, and technical performance described in this report. It summarizes performance for the period covered, highlights areas worthy of management attention, and provides a forward look to some of the upcoming key performance activities as extracted from the contractor baseline. The remaining sections provide detailed performance data relative to each individual Project (e.g., Waste Management, Spent Nuclear Fuels, etc.), in support of Section A of the report. Unless otherwise noted, the Safety, Conduct of Operations, and Cost/Schedule data contained herein is as of July 31, 2001. All other information is updated as of August 22, 2001 unless otherwise noted. ''Stoplight'' boxes are used to indicate at a glance the condition of a particular area. Green boxes denote on schedule. Yellows denote behind schedule but recoverable. Red is either missed or unrecoverable, without agreement by the regulating party

  16. Effect of ferrocene-substituted porphyrin RL-91 on Candida albicans biofilm formation.

    Science.gov (United States)

    Lippert, Rainer; Vojnovic, Sandra; Mitrovic, Aleksandra; Jux, Norbert; Ivanović-Burmazović, Ivana; Vasiljevic, Branka; Stankovic, Nada

    2014-08-01

    Ferrocene-substituted porphyrin RL-91 exhibits antifungal activity against opportune human pathogen Candida albicans. RL-91 efficiently inhibits growth of both planktonic C. albicans cells and cells within biofilms without photoactivation. The minimal inhibitory concentration for plankton form (PMIC) was established to be 100 μg/mL and the same concentration killed 80% of sessile cells in the mature biofilm (SMIC80). Furthermore PMIC of RL-91 efficiently prevents C. albicans biofilm formation. RL-91 is cytotoxic for human fibroblasts in vitro in concentration of 10 μg/mL, however it does not cause hemolysis in concentrations of up to 50 μg/mL. These findings open possibility for application of RL-91 as an antifungal agent for external antibiofilm treatment of medical devices as well as a scaffold for further development of porphyrin based systemic antifungals. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. Is Assessment of Femoral Head Perfusion During Modified Dunn for Unstable Slipped Capital Femoral Epiphysis an Accurate Indicator of Osteonecrosis?

    Science.gov (United States)

    Novais, Eduardo N; Sink, Ernest L; Kestel, Lauryn A; Carry, Patrick M; Abdo, João C M; Heare, Travis C

    2016-08-01

    The modified Dunn procedure, which is an open subcapital realignment through a surgical dislocation approach, has gained popularity for the treatment of unstable slipped capital femoral epiphysis (SCFE). Intraoperative monitoring of the femoral head perfusion has been recommended as a method of predicting osteonecrosis; however, the accuracy of this assessment has not been well documented. We asked (1) whether intraoperative assessment of femoral head perfusion would help identify hips at risk of developing osteonecrosis; (2) whether one of the four methods of assessment of femoral head perfusion is more accurate (highest area under the curve) at identifying hips at risk of osteonecrosis; and (3) whether specific clinical features would be associated with osteonecrosis occurrence after a modified Dunn procedure for unstable SCFE. Between 2007 and 2014, we performed 29 modified Dunn procedures for unstable SCFE (16 boys, 11 girls; median age, 13 years; range, 8-17 years); two were lost to followup before 1 year. During this period, six patients with unstable SCFE were treated by other procedures. All patients undergoing modified Dunn underwent assessment of epiphyseal perfusion by the presence of active bleeding and/or by intracranial pressure (ICP) monitoring. In the initial five patients perfusion was recorded once, either before dissection of the retinacular flap or after fixation by one of the two methods. In the remaining 22 patients (81%), perfusion was systematically assessed before dissection of the retinacular flap and after fixation by both methods. Minimum followup was 1 year (median, 2.5 years; range, 1-8 years) because osteonecrosis typically develops within the first year after surgery. Patients were assessed for osteonecrosis by the presence of femoral head collapse at radiographs obtained every 3 months during the first year after surgery. Seven (26%) of the 27 patients developed osteonecrosis. Measures of diagnostic accuracy including sensitivity

  18. Insights into the Earth System mass variability from CSR-RL05 GRACE gravity fields

    Science.gov (United States)

    Bettadpur, S.

    2012-04-01

    The next-generation Release-05 GRACE gravity field data products are the result of extensive effort applied to the improvements to the GRACE Level-1 (tracking) data products, and to improvements in the background gravity models and processing methodology. As a result, the squared-error upper-bound in RL05 fields is half or less than the squared-error upper-bound in RL04 fields. The CSR-RL05 field release consists of unconstrained gravity fields as well as a regularized gravity field time-series that can be used for several applications without any post-processing error reduction. This paper will describe the background and the nature of these improvements in the data products, and provide an error characterization. We will describe the insights these new series offer in measuring the mass flux due to diverse Hydrologic, Oceanographic and Cryospheric processes.

  19. Comet C2012 S1 (ISON): Observations of the Dust Grains From SOFIA and of the Atomic Gas From NSO Dunn and Mcmath-Pierce Solar Telescopes

    Science.gov (United States)

    Wooden, Diane H.; Woodward, Charles E.; Harker, David E.; Kelley, Michael S. P.; Sitko, Michael; Reach, William T.; De Pater, Imke; Gehrz, Robert D.; Kolokolova, Ludmilla; Cochran, Anita L.; hide

    2013-01-01

    Comet C/2012 S1 (ISON) is unique in that it is a dynamically new comet derived from the Oort cloud reservoir of comets with a sun-grazing orbit. Infrared (IR) and visible wavelength observing campaigns were planned on NASA's Stratospheric Observatory For Infrared Astronomy (SOFIA) and on National Solar Observatory Dunn (DST) and McMath-Pierce Solar Telescopes, respectively. We highlight our SOFIA (+FORCAST) mid- to far-IR images and spectroscopy (approx. 5-35 microns) of the dust in the coma of ISON are to be obtained by the ISON-SOFIA Team during a flight window 2013 Oct 21-23 UT (r_h approx. = 1.18 AU). Dust characteristics, identified through the 10 micron silicate emission feature and its strength, as well as spectral features from cometary crystalline silicates (Forsterite) at 11.05-11.2 microns, and near 16, 19, 23.5, 27.5, and 33 microns are compared with other Oort cloud comets that span the range of small and/or highly porous grains (e.g., C/1995 O1 (Hale-Bopp) and C/2001 Q4 (NEAT) to large and/or compact grains (e.g., C/2007 N4 (Lulin) and C/2006 P1 (McNaught)). Measurement of the crystalline peaks in contrast to the broad 10 and 20 micron amorphous silicate features yields the cometary silicate crystalline mass fraction, which is a benchmark for radial transport in our protoplanetary disk. The central wavelength positions, relative intensities, and feature asymmetries for the crystalline peaks may constrain the shapes of the crystals. Only SOFIA can look for cometary organics in the 5-8 micron region. Spatially resolved measurements of atoms and simple molecules from when comet ISON is near the Sun (r_hmeasures 4 settings: Na I, K, C2 to sample cometary organics (along with Mg I), and [OI] as a proxy for activity from water (along with Si I and Fe I). State-of-the-art instruments that will also be employed include IBIS, which is a Fabry-Perot spectral imaging system that concurrently measures lines of Na, K, Ca II, or Fe, and ROSA (CSUN/QUB), which is a

  20. Accurate calibration of RL shunts for piezoelectric vibration damping of flexible structures

    DEFF Research Database (Denmark)

    Høgsberg, Jan Becker; Krenk, Steen

    2016-01-01

    Piezoelectric RL (resistive-inductive) shunts are passive resonant devices used for damping of dominantvibration modes of a flexible structure and their efficiency relies on precise calibration of the shuntcomponents. In the present paper improved calibration accuracy is attained by an extension...

  1. Anti-Proliferative Effects of Siegesbeckia orientalis Ethanol Extract on Human Endometrial RL-95 Cancer Cells

    Directory of Open Access Journals (Sweden)

    Chi-Chang Chang

    2014-12-01

    Full Text Available Endometrial cancer is a common malignancy of the female genital tract. This study demonstrates that Siegesbeckia orientalis ethanol extract (SOE significantly inhibited the proliferation of RL95-2 human endometrial cancer cells. Treating RL95-2 cells with SOE caused cell arrest in the G2/M phase and induced apoptosis of RL95-2 cells by up-regulating Bad, Bak and Bax protein expression and down-regulation of Bcl-2 and Bcl-xL protein expression. Treatment with SOE increased protein expression of caspase-3, -8 and -9 dose-dependently, indicating that apoptosis was through the intrinsic and extrinsic apoptotic pathways. Moreover, SOE was also effective against A549 (lung cancer, Hep G2 (hepatoma, FaDu (pharynx squamous cancer, MDA-MB-231 (breast cancer, and especially on LNCaP (prostate cancer cell lines. In total, 10 constituents of SOE were identified by Gas chromatography-mass analysis. Caryophyllene oxide and caryophyllene are largely responsible for most cytotoxic activity of SOE against RL95-2 cells. Overall, this study suggests that SOE is a promising anticancer agent for treating endometrial cancer.

  2. Memory effects and systematic errors in the RL signal from fiber coupled Al2O3:C for medical dosimetry

    DEFF Research Database (Denmark)

    Damkjær, Sidsel Marie Skov; Andersen, Claus Erik

    2010-01-01

    This review describes 40 years of experience gained at Risø The radioluminescence (RL) signal from fiber coupled Al2O3:C can be used for real-time in vivo dosimetry during radiotherapy. RL generally provides measurements with a reproducibility of 2% (one standard deviation). However, we have...

  3. The permeability of EUDRAGIT RL and HEMA-MMA microcapsules to glucose and inulin.

    Science.gov (United States)

    Douglas, J A; Sefton, M V

    1990-10-05

    Measurement of the rate of glucose diffusion from EUDGRAGIT RL and HEMA-MMA microcapsules coupled with a Thiele modulus/Biot number analysis of the glucose utilization rate suggests that pancreatic islets and CHO (Chinese hamster ovary) cells (at moderate to high cell densities) should not be adversely affected by the diffusion restrictions associated with these capsule membranes. The mass transfer coefficients for glucose at 20 degrees C were of the same order of magnitude for both capsules, based on release measurements: approximately 5 x 10(-6) cm/s for EUDRAGIT RL and approximately 2 x 10(-6) for HEMA-MMA. Inulin release from EUDRAGIT RL was slower than for glucose (mass transfer coefficient 14 +/- 4 x 10(-8) cm/s). The Thiele moduli were much less than 1, either for a single islet at the center of a capsule or CHO cells uniformly distributed throughout a capsule at 10(-6) cells/ mL, so that diffusion restrictions within the cells in EUDRAGIT RL or 800 microm HEMA-MMA capsules should be negligible. The ratio of external to internal diffusion resistance (Biot number) was less than 1, so that at most, only a small diffusion effect on glucose utilization should be expected (i.e., the overall effectiveness factors were greater than 0.8). These calculations were consistent with experimental observation of encapsulated islet behavior but not fully with CHO cell behavior. Permeability restricted cell viability and growth is potentially a major limitation of encapsulated cells; further analysis is warranted.

  4. CAD2RL: Real Single-Image Flight without a Single Real Image

    OpenAIRE

    Sadeghi, Fereshteh; Levine, Sergey

    2016-01-01

    Deep reinforcement learning has emerged as a promising and powerful technique for automatically acquiring control policies that can process raw sensory inputs, such as images, and perform complex behaviors. However, extending deep RL to real-world robotic tasks has proven challenging, particularly in safety-critical domains such as autonomous flight, where a trial-and-error learning process is often impractical. In this paper, we explore the following question: can we train vision-based navig...

  5. PeRL: a circum-Arctic Permafrost Region Pond and Lake database

    Science.gov (United States)

    Muster, Sina; Roth, Kurt; Langer, Moritz; Lange, Stephan; Cresto Aleina, Fabio; Bartsch, Annett; Morgenstern, Anne; Grosse, Guido; Jones, Benjamin; Sannel, A. Britta K.; Sjöberg, Ylva; Günther, Frank; Andresen, Christian; Veremeeva, Alexandra; Lindgren, Prajna R.; Bouchard, Frédéric; Lara, Mark J.; Fortier, Daniel; Charbonneau, Simon; Virtanen, Tarmo A.; Hugelius, Gustaf; Palmtag, Juri; Siewert, Matthias B.; Riley, William J.; Koven, Charles D.; Boike, Julia

    2017-06-01

    Ponds and lakes are abundant in Arctic permafrost lowlands. They play an important role in Arctic wetland ecosystems by regulating carbon, water, and energy fluxes and providing freshwater habitats. However, ponds, i.e., waterbodies with surface areas smaller than 1. 0 × 104 m2, have not been inventoried on global and regional scales. The Permafrost Region Pond and Lake (PeRL) database presents the results of a circum-Arctic effort to map ponds and lakes from modern (2002-2013) high-resolution aerial and satellite imagery with a resolution of 5 m or better. The database also includes historical imagery from 1948 to 1965 with a resolution of 6 m or better. PeRL includes 69 maps covering a wide range of environmental conditions from tundra to boreal regions and from continuous to discontinuous permafrost zones. Waterbody maps are linked to regional permafrost landscape maps which provide information on permafrost extent, ground ice volume, geology, and lithology. This paper describes waterbody classification and accuracy, and presents statistics of waterbody distribution for each site. Maps of permafrost landscapes in Alaska, Canada, and Russia are used to extrapolate waterbody statistics from the site level to regional landscape units. PeRL presents pond and lake estimates for a total area of 1. 4 × 106 km2 across the Arctic, about 17 % of the Arctic lowland ( pangaea.de/10.1594/PANGAEA.868349" target="_blank">https://doi.pangaea.de/10.1594/PANGAEA.868349.

  6. Mutation of a Broadly Conserved Operon (RL3499-RL3502) from Rhizobium leguminosarum Biovar viciae Causes Defects in Cell Morphology and Envelope Integrity▿†

    Science.gov (United States)

    Vanderlinde, Elizabeth M.; Magnus, Samantha A.; Tambalo, Dinah D.; Koval, Susan F.; Yost, Christopher K.

    2011-01-01

    The bacterial cell envelope is of critical importance to the function and survival of the cell; it acts as a barrier against harmful toxins while allowing the flow of nutrients into the cell. It also serves as a point of physical contact between a bacterial cell and its host. Hence, the cell envelope of Rhizobium leguminosarum is critical to cell survival under both free-living and symbiotic conditions. Transposon mutagenesis of R. leguminosarum strain 3841 followed by a screen to isolate mutants with defective cell envelopes led to the identification of a novel conserved operon (RL3499-RL3502) consisting of a putative moxR-like AAA+ ATPase, a hypothetical protein with a domain of unknown function (designated domain of unknown function 58), and two hypothetical transmembrane proteins. Mutation of genes within this operon resulted in increased sensitivity to membrane-disruptive agents such as detergents, hydrophobic antibiotics, and alkaline pH. On minimal media, the mutants retain their rod shape but are roughly 3 times larger than the wild type. On media containing glycine or peptides such as yeast extract, the mutants form large, distorted spheres and are incapable of sustained growth under these culture conditions. Expression of the operon is maximal during the stationary phase of growth and is reduced in a chvG mutant, indicating a role for this sensor kinase in regulation of the operon. Our findings provide the first functional insight into these genes of unknown function, suggesting a possible role in cell envelope development in Rhizobium leguminosarum. Given the broad conservation of these genes among the Alphaproteobacteria, the results of this study may also provide insight into the physiological role of these genes in other Alphaproteobacteria, including the animal pathogen Brucella. PMID:21357485

  7. PeRL: A circum-Arctic Permafrost Region Pond and Lake database

    Science.gov (United States)

    Muster, Sina; Roth, Kurt; Langer, Moritz; Lange, Stephan; Cresto Aleina, Fabio; Bartsch, Annett; Morgenstern, Anne; Grosse, Guido; Jones, Benjamin; Sannel, A.B.K.; Sjoberg, Ylva; Gunther, Frank; Andresen, Christian; Veremeeva, Alexandra; Lindgren, Prajna R.; Bouchard, Frédéric; Lara, Mark J.; Fortier, Daniel; Charbonneau, Simon; Virtanen, Tarmo A.; Hugelius, Gustaf; Palmtag, J.; Siewert, Matthias B.; Riley, William J.; Koven, Charles; Boike, Julia

    2017-01-01

    Ponds and lakes are abundant in Arctic permafrost lowlands. They play an important role in Arctic wetland ecosystems by regulating carbon, water, and energy fluxes and providing freshwater habitats. However, ponds, i.e., waterbodies with surface areas smaller than 1. 0 × 104 m2, have not been inventoried on global and regional scales. The Permafrost Region Pond and Lake (PeRL) database presents the results of a circum-Arctic effort to map ponds and lakes from modern (2002–2013) high-resolution aerial and satellite imagery with a resolution of 5 m or better. The database also includes historical imagery from 1948 to 1965 with a resolution of 6 m or better. PeRL includes 69 maps covering a wide range of environmental conditions from tundra to boreal regions and from continuous to discontinuous permafrost zones. Waterbody maps are linked to regional permafrost landscape maps which provide information on permafrost extent, ground ice volume, geology, and lithology. This paper describes waterbody classification and accuracy, and presents statistics of waterbody distribution for each site. Maps of permafrost landscapes in Alaska, Canada, and Russia are used to extrapolate waterbody statistics from the site level to regional landscape units. PeRL presents pond and lake estimates for a total area of 1. 4 × 106 km2 across the Arctic, about 17 % of the Arctic lowland ( s.l.) land surface area. PeRL waterbodies with sizes of 1. 0 × 106 m2 down to 1. 0 × 102 m2 contributed up to 21 % to the total water fraction. Waterbody density ranged from 1. 0 × 10 to 9. 4 × 101 km−2. Ponds are the dominant waterbody type by number in all landscapes representing 45–99 % of the total waterbody number. The implementation of PeRL size distributions in land surface models will greatly improve the investigation and projection of surface inundation and carbon fluxes in permafrost lowlands. Waterbody maps, study area

  8. Cycloheximide and 4-OH-TEMPO suppress chloramphenicol-induced apoptosis in RL-34 cells via the suppression of the formation of megamitochondria.

    Science.gov (United States)

    Karbowski, M; Kurono, C; Wozniak, M; Ostrowski, M; Teranishi, M; Soji, T; Wakabayashi, T

    1999-02-04

    Toxic effects of chloramphenicol, an antibiotic inhibitor of mitochondrial protein synthesis, on rat liver derived RL-34 cell line were completely blocked by a combined treatment with substances endowed with direct or indirect antioxidant properties. A stable, nitroxide free radical scavenger, 4-hydroxy-2,2,6, 6-tetramethylpiperidine-1-oxyl, and a protein synthesis inhibitor, cycloheximide, suppressed in a similar manner the following manifestations of the chloramphenicol cytotoxicity: (1) Oxidative stress state as evidenced by FACS analysis of cells loaded with carboxy-dichlorodihydrofluorescein diacetate and Mito Tracker CMTH2MRos; (2) megamitochondria formation detected by staining of mitochondria with MitoTracker CMXRos under a laser confocal microscopy and electron microscopy; (3) apoptotic changes of the cell detected by the phase contrast microscopy, DNA laddering analysis and cell cycle analysis. Since increases of ROS generation in chloramphenicol-treated cells were the first sign of the chloramphenicol toxicity, we assume that oxidative stress state is a mediator of above described alternations of RL-34 cells including MG formation. Pretreatment of cells with cycloheximide or 4-hydroxy-2,2, 6,6-tetramethylpiperidine-1-oxyl, which is known to be localized into mitochondria, inhibited the megamitochondria formation and succeeding apoptotic changes of the cell. Protective effects of cycloheximide, which enhances the expression of Bcl-2 protein, may further confirm our hypothesis that the megamitochondria formation is a cellular response to an increased ROS generation and raise a possibility that antiapoptotic action of the drug is exerted via the protection of the mitochondria functions.

  9. Cross-Calibrating Sunspot Magnetic Field Strength Measurements from the McMath-Pierce Solar Telescope and the Dunn Solar Telescope

    Science.gov (United States)

    Watson, Fraser T.; Beck, Christian; Penn, Matthew J.; Tritschler, Alexandra; Pillet, Valentín Martinez; Livingston, William C.

    2015-11-01

    In this article we describe a recent effort to cross-calibrate data from an infrared detector at the McMath-Pierce Solar Telescope and the Facility InfraRed Spectropolarimeter (FIRS) at the Dunn Solar Telescope. A synoptic observation program at the McMath-Pierce has measured umbral magnetic field strengths since 1998, and this data set has recently been compared with umbral magnetic field observations from SOHO/MDI and SDO/HMI. To further improve on the data from McMath-Pierce, we compared the data with measurements taken at the Dunn Solar Telescope with far greater spectral resolution than has been possible with space instrumentation. To minimise potential disruption to the study, concurrent umbral measurements were made so that the relationship between the two datasets can be most accurately characterised. We find that there is a strong agreement between the umbral magnetic field strengths recorded by each instrument, and we reduced the FIRS data in two different ways to successfully test this correlation further.

  10. LATENCIA DEL HERPESVIRUS BOVINO-1: EL PAPEL DE LOS TRANSCRITOS RELACIONADOS CON LATENCIA (RL

    Directory of Open Access Journals (Sweden)

    JULIÁN, RUIZ

    2008-01-01

    Full Text Available El herpesvirus bovino-1 es un virus de distribución mundial causante de graves pérdidas económicas debidas principalmente a la disminución de la eficiencia y en los indicadores de salud y productividad de cualquier hato ganadero infectado. Luego de la infección inicial del tracto respiratorio de los animales, el virus establece un estado de latencia viral en las neuronas sensoriales del ganglio trigémino y en los centros germinales de las tonsilas faríngeas. Periódicamente, el virus es reactivado y excretado en secreciones a través de las cuales puede infectar a otros animales susceptibles. Durante dicho estado de latencia hay disminución dramática de la expresión de genes virales, llevando solo a la expresión de dos transcritos: El RNA codificado por el gen relacionado con latencia (RL y el ORF-E viral. Múltiples estudios demuestran como el RL y el ORF-E están involucrados en la regulación del complejo ciclo de latencia y reactivación de la infección. La presente revisión de literatura se enfocará en describir y analizar los distintos estudios que han llevado a dilucidar el papel jugado por el gen RL y el ORF-E, sus transcritos y sus productos proteicos en el establecimiento, mantenimiento y reactivación de la latencia del HVB-1.

  11. High-frequency signal and noise estimates of CSR GRACE RL04

    Science.gov (United States)

    Bonin, Jennifer A.; Bettadpur, Srinivas; Tapley, Byron D.

    2012-12-01

    A sliding window technique is used to create daily-sampled Gravity Recovery and Climate Experiment (GRACE) solutions with the same background processing as the official CSR RL04 monthly series. By estimating over shorter time spans, more frequent solutions are made using uncorrelated data, allowing for higher frequency resolution in addition to daily sampling. Using these data sets, high-frequency GRACE errors are computed using two different techniques: assuming the GRACE high-frequency signal in a quiet area of the ocean is the true error, and computing the variance of differences between multiple high-frequency GRACE series from different centers. While the signal-to-noise ratios prove to be sufficiently high for confidence at annual and lower frequencies, at frequencies above 3 cycles/year the signal-to-noise ratios in the large hydrological basins looked at here are near 1.0. Comparisons with the GLDAS hydrological model and high frequency GRACE series developed at other centers confirm CSR GRACE RL04's poor ability to accurately and reliably measure hydrological signal above 3-9 cycles/year, due to the low power of the large-scale hydrological signal typical at those frequencies compared to the GRACE errors.

  12. Exposure to welding fumes is associated with hypomethylation of the F2RL3 gene: a cardiovascular disease marker.

    Science.gov (United States)

    Hossain, Mohammad B; Li, Huiqi; Hedmer, Maria; Tinnerberg, Håkan; Albin, Maria; Broberg, Karin

    2015-12-01

    Welders are at risk for cardiovascular disease. Recent studies linked tobacco smoke exposure to hypomethylation of the F2RL3 (coagulation factor II (thrombin) receptor-like 3) gene, a marker for cardiovascular disease prognosis and mortality. However, whether welding fumes cause hypomethylation of F2RL3 remains unknown. We investigated 101 welders (median span of working as a welder: 7 years) and 127 unexposed controls (non-welders with no obvious exposure to respirable dust at work), age range 23-60 years, all currently non-smoking, in Sweden. The participants were interviewed about their work history, lifestyle factors and diseases. Personal sampling of respirable dust was performed for the welders. DNA methylation of F2RL3 in blood was assessed by pyrosequencing of four CpG sites, CpG_2 (corresponds to cg03636183) to CpG_5, in F2RL3. Multivariable linear regression analysis was used to assess the association between exposure to welding fumes and F2RL3 methylation. Welders had 2.6% lower methylation of CpG_5 than controls (pWelding fumes exposure and previous smoking were associated with F2RL3 hypomethylation. This finding links low-to-moderate exposure to welding fumes to adverse effects on the cardiovascular system, and suggests a potential mechanistic pathway for this link, via epigenetic effects on F2RL3 expression. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  13. Kino repertuāra pārlūks Android ierīcēm

    OpenAIRE

    Zvirbulis, Jānis

    2013-01-01

    Kvalifikācijas darbā “Kino repertuāra pārlūks Android ierīcēm” tiek aprakstīta Android lietojumprogrammas “Kino repertuāra pārlūks” izstrāde un funkcionalitāte. Lietotne paredzēta kinoteātra repertuāra aplūkošanai izmantojot planšetdatorus un mobilos tālruņus, kas darbojas ar Android operētājsistēmu. Tā ir domāta kā parocīgāka alternatīva filmu apraksta un seansa laiku uzzināšanai caur kinoteātra mājaslapu, skrejlapām vai afišām. Atslēgvārdi: Android, filmas, pārlūks....

  14. A comparative mathematical analysis of RL and RC electrical circuits via Atangana-Baleanu and Caputo-Fabrizio fractional derivatives

    Science.gov (United States)

    Abro, Kashif Ali; Memon, Anwar Ahmed; Uqaili, Muhammad Aslam

    2018-03-01

    This research article is analyzed for the comparative study of RL and RC electrical circuits by employing newly presented Atangana-Baleanu and Caputo-Fabrizio fractional derivatives. The governing ordinary differential equations of RL and RC electrical circuits have been fractionalized in terms of fractional operators in the range of 0 ≤ ξ ≤ 1 and 0 ≤ η ≤ 1. The analytic solutions of fractional differential equations for RL and RC electrical circuits have been solved by using the Laplace transform with its inversions. General solutions have been investigated for periodic and exponential sources by implementing the Atangana-Baleanu and Caputo-Fabrizio fractional operators separately. The investigated solutions have been expressed in terms of simple elementary functions with convolution product. On the basis of newly fractional derivatives with and without singular kernel, the voltage and current have interesting behavior with several similarities and differences for the periodic and exponential sources.

  15. UAS Conflict-Avoidance Using Multiagent RL with Abstract Strategy Type Communication

    Science.gov (United States)

    Rebhuhn, Carrie; Knudson, Matt; Tumer, Kagan

    2014-01-01

    The use of unmanned aerial systems (UAS) in the national airspace is of growing interest to the research community. Safety and scalability of control algorithms are key to the successful integration of autonomous system into a human-populated airspace. In order to ensure safety while still maintaining efficient paths of travel, these algorithms must also accommodate heterogeneity of path strategies of its neighbors. We show that, using multiagent RL, we can improve the speed with which conflicts are resolved in cases with up to 80 aircraft within a section of the airspace. In addition, we show that the introduction of abstract agent strategy types to partition the state space is helpful in resolving conflicts, particularly in high congestion.

  16. Announced Strategy Types in Multiagent RL for Conflict-Avoidance in the National Airspace

    Science.gov (United States)

    Rebhuhn, Carrie; Knudson, Matthew D.; Tumer, Kagan

    2014-01-01

    The use of unmanned aerial systems (UAS) in the national airspace is of growing interest to the research community. Safety and scalability of control algorithms are key to the successful integration of autonomous system into a human-populated airspace. In order to ensure safety while still maintaining efficient paths of travel, these algorithms must also accommodate heterogeneity of path strategies of its neighbors. We show that, using multiagent RL, we can improve the speed with which conflicts are resolved in cases with up to 80 aircraft within a section of the airspace. In addition, we show that the introduction of abstract agent strategy types to partition the state space is helpful in resolving conflicts, particularly in high congestion.

  17. Comparison Between CCCM and CloudSat Radar-Lidar (RL) Cloud and Radiation Products

    Science.gov (United States)

    Ham, Seung-Hee; Kato, Seiji; Rose, Fred G.; Sun-Mack, Sunny

    2015-01-01

    To enhance cloud properties, LaRC and CIRA developed each combination algorithm for obtained properties from passive, active and imager in A-satellite constellation. When comparing global cloud fraction each other, LaRC-produced CERES-CALIPSO-CloudSat-MODIS (CCCM) products larger low-level cloud fraction over tropic ocean, while CIRA-produced Radar-Lidar (RL) shows larger mid-level cloud fraction for high latitude region. The reason for different low-level cloud fraction is due to different filtering method of lidar-detected cloud layers. Meanwhile difference in mid-level clouds is occurred due to different priority of cloud boundaries from lidar and radar.

  18. Nickel detoxification and plant growth promotion by multi metal resistant plant growth promoting Rhizobium species RL9.

    Science.gov (United States)

    Wani, Parvaze Ahmad; Khan, Mohammad Saghir

    2013-07-01

    Pollution of the biosphere by heavy metals is a global threat that has accelerated dramatically since the beginning of industrial revolution. The aim of the study is to check the resistance of RL9 towards the metals and to observe the effect of Rhizobium species on growth, pigment content, protein and nickel uptake by lentil in the presence and absence of nickel. The multi metal tolerant and plant growth promoting Rhizobium strain RL9 was isolated from the nodules of lentil. The strain not only tolerated nickel but was also tolerant o cadmium, chromium, nickel, lead, zinc and copper. The strain tolerated nickel 500 μg/mL, cadmium 300 μg/mL, chromium 400 μg/mL, lead 1,400 μg/mL, zinc 1,000 μg/mL and copper 300 μg/mL, produced good amount of indole acetic acid and was also positive for siderophore, hydrogen cyanide and ammonia. The strain RL9 was further assessed with increasing concentrations of nickel when lentil was used as a test crop. The strain RL9 significantly increased growth, nodulation, chlorophyll, leghaemoglobin, nitrogen content, seed protein and seed yield compared to plants grown in the absence of bioinoculant but amended with nickel The strain RL9 decreased uptake of nickel in lentil compared to plants grown in the absence of bio-inoculant. Due to these intrinsic abilities strain RL9 could be utilized for growth promotion as well as for the remediation of nickel in nickel contaminated soil.

  19. Tumor Cells Express FcγRl Which Contributes to Tumor Cell Growth and a Metastatic Phenotype

    Directory of Open Access Journals (Sweden)

    M. Bud Nelson

    2001-01-01

    Full Text Available High levels of circulating immune complexes containing tumor-associated antigens are associated with a poor prognosis for individuals with cancer. The ability of B cells, previously exposed to tumor-associated antigens, to promote both in vitro and in vivo tumor growth formed the rationale to evaluate the mechanism by which immune complexes may promote tumor growth. In elucidating this mechanism, FcγRl expression by tumor cells was characterized by flow cytometry, polymerase chain reaction, and sequence analysis. Immune complexes containing shed tumor antigen and anti-shed tumor antigen Ab cross-linked FcγRl-expressing tumor cells, which resulted in an induction of tumor cell proliferation and of shed tumor antigen production. Use of selective tyrosine kinase inhibitors demonstrated that tumor cell proliferation induced by immune complex cross-linking of FcγRl is dependent on the tyrosine kinase signal transduction pathway. A selective inhibitor of phosphatidylinositol-3 kinase also inhibited this induction of tumor cell proliferation. These findings support a role for immune complexes and FcγRl expression by tumor cells in augmentation of tumor growth and a metastatic phenotype.

  20. A new 2DS·2RL Robertsonian translocation transfers stem rust resistance gene Sr59 into wheat.

    Science.gov (United States)

    Rahmatov, Mahbubjon; Rouse, Matthew N; Nirmala, Jayaveeramuthu; Danilova, Tatiana; Friebe, Bernd; Steffenson, Brian J; Johansson, Eva

    2016-07-01

    A new stem rust resistance gene Sr59 from Secale cereale was introgressed into wheat as a 2DS·2RL Robertsonian translocation. Emerging new races of the wheat stem rust pathogen (Puccinia graminis f. sp. tritici), from Africa threaten global wheat (Triticum aestivum L.) production. To broaden the resistance spectrum of wheat to these widely virulent African races, additional resistance genes must be identified from all possible gene pools. From the screening of a collection of wheat-rye (Secale cereale L.) chromosome substitution lines developed at the Swedish University of Agricultural Sciences, we described the line 'SLU238' 2R (2D) as possessing resistance to many races of P. graminis f. sp. tritici, including the widely virulent race TTKSK (isolate synonym Ug99) from Africa. The breakage-fusion mechanism of univalent chromosomes was used to produce a new Robertsonian translocation: T2DS·2RL. Molecular marker analysis and stem rust seedling assays at multiple generations confirmed that the stem rust resistance from 'SLU238' is present on the rye chromosome arm 2RL. Line TA5094 (#101) was derived from 'SLU238' and was found to be homozygous for the T2DS·2RL translocation. The stem rust resistance gene on chromosome 2RL arm was designated as Sr59. Although introgressions of rye chromosome arms into wheat have most often been facilitated by irradiation, this study highlights the utility of the breakage-fusion mechanism for rye chromatin introgression. Sr59 provides an additional asset for wheat improvement to mitigate yield losses caused by stem rust.

  1. Deslizamientos epifisarios femorales proximales >30º. Procedimiento de Dunn modificado. Evaluación anatómica y funcional en una cohorte retrospectiva. [Slipped capital femoral epiphysis >30º. Modified Dunn procedure. Anatomical and functional evaluation in a retrospective cohort

    Directory of Open Access Journals (Sweden)

    Francisco Praglia

    2013-12-01

    Full Text Available Introducción La deformidad residual resultante de un deslizamiento epifisario femoral proximal moderado o grave conduce a osteoartritis prematura debida al choque femoroacetabular. Los objetivos del trabajo fueron evaluar la mejoría de la anatomía del fémur proximal y evaluar la función de la cadera en pacientes con deslizamiento epifisario femoral proximal >30 grados tratados con el procedimiento de Dunn modificado, a corto plazo. Material y Métodos Cohorte retrospectiva de pacientes con deslizamiento epifisario femoral proximal >30 grados, tratados con luxación controlada de cadera y el procedimiento de Dunn modificado. Se evaluaron mediciones clínicas y radiológicas preoperatorias y posoperatorias, hallazgos intraoperatorios y funcionalidad con los puntajes de Harris y de D’aubigne-Postel. Resultados Trece casos, mediana de edad 12 años y mediana de seguimiento 14 meses. El ángulo de deslizamiento de Southwick preoperatorio (75 grados, ri 67-85 y posoperatorio (10 grados, ri 5-17 mostró una disminución estadísticamente significativa (p <0,001. El offset radio cabeza-cuello preoperatorio (-0,13 versus el posoperatorio (0,12 obtuvo una mejoría significativa (p 0,002. El 69,2% de los pacientes presentó daño de alguna estructura intraarticular. Los puntajes promedio de funcionalidad fueron 14,6 (muy buena mejoría y 83,4 (bueno. Complicaciones: necrosis avascular 15,3% y condrólisis 15,3%. Conclusion Esta técnica restaura la anatomía del fémur proximal y la funcionalidad de la cadera a corto plazo. aunque no disponemos de resultados a largo plazo, al menos en teoría, serían buenos. Sin embargo, la luxación controlada con Dunn modificado no está exenta de complicaciones y el riesgo de necrosis avascular y condrólisis persiste.

  2. Pharmacologically induced long QT type 2 can be rescued by activation of IKs with benzodiazepine R-L3 in isolated guinea pig cardiomyocytes

    DEFF Research Database (Denmark)

    Nissen, Jakob Dahl; Diness, Jonas Goldin; Diness, Thomas Goldin

    2009-01-01

    of this study was to evaluate potential antiarrhythmic effects of compound induced IKs activation using the benzodiazepine L-364,373 (R-L3). Ventricular myocytes from guinea pigs were isolated and whole-cell current clamping was performed at 35 degrees C. It was found that 1 microM R-L3 significantly reduced...

  3. The production of arabitol by a novel plant yeast isolate Candida parapsilosis 27RL-4

    Directory of Open Access Journals (Sweden)

    Kordowska-Wiater Monika

    2017-10-01

    Full Text Available Polyalcohol arabitol can be used in the food and pharmaceutical industries as a natural sweetener, a dental caries reducer, and texturing agent. Environmental samples were screened to isolate effective yeast producers of arabitol. The most promising isolate 27RL-4, obtained from raspberry leaves, was identified genetically and biochemically as Candida parapsilosis. It secreted 10.42– 10.72 g l-1 of product from 20 g l-1 of L-arabinose with a yield of 0.51 - 0.53 g g-1 at 28°C and a rotational speed of 150 rpm. Batch cultures showed that optimal pH value for arabitol production was 5.5. High yields and productivities of arabitol were obtained during incubation of the yeast at 200 rpm, or at 32°C, but the concentrations of the polyol did not exceed 10 g l-1. In modified medium, with reduced amounts of nitrogen compounds and pH 5.5-6.5, lower yeast biomass produced a similar concentration of arabitol, suggesting higher efficiency of yeast cells. This strain also produced arabitol from glucose, with much lower yields. The search for new strains able to successfully produce arabitol is important for allowing the utilization of sugars abundant in plant biomass.

  4. Balanced calibration of resonant piezoelectric RL shunts with quasi-static background flexibility correction

    DEFF Research Database (Denmark)

    Høgsberg, Jan Becker; Krenk, Steen

    2015-01-01

    Resonant RL shunt circuits constitute a robust approach to piezoelectric damping, where the performance with respect to damping of flexible structures requires a precise calibration of the corresponding circuit components. The balanced calibration procedure of the present paper is based on equal ...... that the procedure leads to equal modal damping and effective response reduction, even for rather indirect placement of the transducer, provided that the correction for background flexibility is included in the calibration procedure....

  5. EDA Çekirdekli Amin, TRIS ve Karboksil Sonlu PAMAM Dendrimerleri Kullanarak Ketoprofenin Çözünürlüğünü Geliştirme

    Directory of Open Access Journals (Sweden)

    Ali Serol ERTÜRK

    2017-10-01

    Full Text Available Steroid olmayan antienflamatuar (NSAİ ilaçlar ağrı kesici, ateş düşürücü ve antiinflamatuar etkilerinden dolayı yaygın bir şekilde kullanılmaktadırlar. Son yıllarda NSAİ ilaçların iyi bilinen klasik etkilerinin yanında birçok farklı terapötik etkilerinin (kanser, Alzheimer ve Parkinson hastalıkları de bulunduğu keşfedilmiştir. Sonuçlar gösteriyor ki, poli(amidoamin (PAMAM dendrimerler varlığında ketoprofen’in (KETO sudaki çözünürlüğü jenerasyon büyüklüğü (E2-E4 ve dendrimer konsantrasyonun (0-2 mM artmasıyla önemli ölçüde geliştirilmiştir. KETO’nun (0.22 ± 0.003 mg/mL çözünürlüğünü arttırmada PAMAM dendrimerlerin rolü E4.TRIS (52.77 ± 2.06 mg/mL> E4.COOH (36.42 ± 0.54 mg/mL> E3.TRIS (13.70 ± 0.17 mg/mL> E3.COOH (11.97 ± 0.14 mg/mL> E4.NH2 (6.53 ± 0.19 mg/mL> E2.COOH (5.95 ± 0.10 mg/mL> E2.TRIS (5.72 ± 0.10 mg/mL> E3.NH2 (4.21 ± 0.04 mg/mL> E2.NH2 (2.35 ± 0.04 mg/mL sırasına göre ve 0.002 M dendrimer varlığında 11 ile 240 kat aralığındadır.

  6. HYDROLOGY, DUNN COUNTY, WI, USA

    Data.gov (United States)

    Federal Emergency Management Agency, Department of Homeland Security — Hydrology data include spatial datasets and data tables necessary for documenting the hydrologic procedures for estimating flood discharges for a flood insurance...

  7. Uptake of Eudragit Retard L (Eudragit® RL Nanoparticles by Human THP-1 Cell Line and Its Effects on Hematology and Erythrocyte Damage in Rats

    Directory of Open Access Journals (Sweden)

    Mosaad A. Abdel-Wahhab

    2014-02-01

    Full Text Available The aim of this study was to prepare Eudragit Retard L (Eudragit RL nanoparticles (ENPs and to determine their properties, their uptake by the human THP-1 cell line in vitro and their effect on the hematological parameters and erythrocyte damage in rats. ENPs showed an average size of 329.0 ± 18.5 nm, a positive zeta potential value of +57.5 ± 5.47 mV and nearly spherical shape with a smooth surface. THP-1 cell lines could phagocyte ENPs after 2 h of incubation. In the in vivo study, male Sprague-Dawley rats were exposed orally or intraperitoneally (IP with a single dose of ENP (50 mg/kg body weight. Blood samples were collected after 4 h, 48 h, one week and three weeks for hematological and erythrocytes analysis. ENPs induced significant hematological disturbances in platelets, red blood cell (RBC total and differential counts of white blood cells (WBCs after 4 h, 48 h and one week. ENP increased met-Hb and Co-Hb derivatives and decreased met-Hb reductase activity. These parameters were comparable to the control after three weeks when administrated orally. It could be concluded that the route of administration has a major effect on the induction of hematological disturbances and should be considered when ENPs are applied for drug delivery systems.

  8. PeRL: a circum-Arctic Permafrost Region Pond and Lake database

    Directory of Open Access Journals (Sweden)

    S. Muster

    2017-06-01

    Full Text Available Ponds and lakes are abundant in Arctic permafrost lowlands. They play an important role in Arctic wetland ecosystems by regulating carbon, water, and energy fluxes and providing freshwater habitats. However, ponds, i.e., waterbodies with surface areas smaller than 1. 0 × 104 m2, have not been inventoried on global and regional scales. The Permafrost Region Pond and Lake (PeRL database presents the results of a circum-Arctic effort to map ponds and lakes from modern (2002–2013 high-resolution aerial and satellite imagery with a resolution of 5 m or better. The database also includes historical imagery from 1948 to 1965 with a resolution of 6 m or better. PeRL includes 69 maps covering a wide range of environmental conditions from tundra to boreal regions and from continuous to discontinuous permafrost zones. Waterbody maps are linked to regional permafrost landscape maps which provide information on permafrost extent, ground ice volume, geology, and lithology. This paper describes waterbody classification and accuracy, and presents statistics of waterbody distribution for each site. Maps of permafrost landscapes in Alaska, Canada, and Russia are used to extrapolate waterbody statistics from the site level to regional landscape units. PeRL presents pond and lake estimates for a total area of 1. 4 × 106 km2 across the Arctic, about 17 % of the Arctic lowland ( <  300 m a.s.l. land surface area. PeRL waterbodies with sizes of 1. 0 × 106 m2 down to 1. 0 × 102 m2 contributed up to 21 % to the total water fraction. Waterbody density ranged from 1. 0 × 10 to 9. 4 × 101 km−2. Ponds are the dominant waterbody type by number in all landscapes representing 45–99 % of the total waterbody number. The implementation of PeRL size distributions in land surface models will greatly improve the investigation and projection of surface inundation and carbon fluxes in permafrost lowlands

  9. R/L, a double reporter mouse line that expresses luciferase gene upon Cre-mediated excision, followed by inactivation of mRFP expression.

    Science.gov (United States)

    Jia, Junshuang; Lin, Xiaolin; Lin, Xia; Lin, Taoyan; Chen, Bangzhu; Hao, Weichao; Cheng, Yushuang; Liu, Yu; Dian, Meijuan; Yao, Kaitai; Xiao, Dong; Gu, Weiwang

    2016-10-01

    The Cre/loxP system has become an important tool for the conditional gene knockout and conditional gene expression in genetically engineered mice. The applications of this system depend on transgenic reporter mouse lines that provide Cre recombinase activity with a defined cell type-, tissue-, or developmental stage-specificity. To develop a sensitive assay for monitoring Cre-mediated DNA excisions in mice, we generated Cre-mediated excision reporter mice, designated R/L mice (R/L: mRFP(monomeric red fluorescent protein)/luciferase), express mRFP throughout embryonic development and adult stages, while Cre-mediated excision deletes a loxP-flanked mRFP reporter gene and STOP sequence, thereby activating the expression of the second reporter gene luciferase, as assayed by in vivo and ex vivo bioluminescence imaging. After germ line deletion of the floxed mRFP and STOP sequence in R/L mice by EIIa-Cre mice, the resulting luciferase transgenic mice in which the loxP-mRFP-STOP-loxP cassette is excised from all cells express luciferase in all tissues and organs examined. The expression of luciferase transgene was activated in liver of RL/Alb-Cre double transgenic mice and in brain of RL/Nestin-Cre double transgenic mice when R/L reporter mice were mated with Alb-Cre mice and Nestin-Cre mice, respectively. Our findings reveal that the double reporter R/L mouse line is able to indicate the occurrence of Cre-mediated excision from early embryonic to adult lineages. Taken together, these findings demonstrate that the R/L mice serve as a sensitive reporter for Cre-mediated DNA excision both in living animals and in organs, tissues, and cells following necropsy.

  10. Effect of artificial hyperglycemia and dissection of the primary focus on metastatic spreading of carcinoma RL-67

    International Nuclear Information System (INIS)

    Istomin, Yu.P.; Furmanchuk, A.V.

    1988-01-01

    In the experiments on the C57B1 mice the authors studied the effect of artificial hyperglycemia (AH), amputation of the extremities with tumors as well as combinations of these effects on the intensity of metastatic spreading of carcinoma RL-67 to the lungs. AH did not prove to intensify the process of metastatic spreading if it was conducted on the 1, 3, 5, 7, 9 and 11th days. The average number of metastases did not differ from that in the control group. AH which was conducted one day before amputation of the extremety with the tumor caused a more significant inhibition of metastatic spreading than a surgical intervention

  11. 216-A-29 Ditch supplemental information to the Hanford Facility Contingency Plan (DOE/RL-93-75)

    International Nuclear Information System (INIS)

    Ingle, S.J.

    1996-05-01

    This document is a unit-specific contingency plan for the 216-A-29 Ditch and is intended to be used as a supplement to DOE/RL-93-75, Hanford Facility Contingency Plan (DOE-RL 1993). This unit-specific plan is to be used to demonstrate compliance with the contingency plan requirements of the Washington Administrative Code, Chapter 173- 303 for certain Resource Conservation and Recovery Act of 1976 waste management units. The 216-A-29 Ditch is a surface impoundment that received nonregulated process and cooling water and other dangerous wastes primarily from operations of the Plutonium/Uranium Extraction Plant. Active between 1955 and 1991, the ditch has been physically isolated and will be closed. Because it is no longer receiving discharges, waste management activities are no longer required at the unit. The ditch does not present a significant hazard to adjacent units, personnel, or the environment. It is unlikely that any incidents presenting hazards to public health or the environment would occur at the 216-A-29 Ditch

  12. 216-U-12 Crib supplemental information to the Hanford Facility Contingency Plan (DOE/RL-93-75)

    International Nuclear Information System (INIS)

    Ingle, S.J.

    1996-05-01

    This document is a unit-specific contingency plan for the 216-U-12 Crib and is intended to be used as a supplement to DOE/RL-93-75, Hanford Facility Contingency Plan (DOE-RL 1993). This unit-specific plan is to be used to demonstrate compliance with the contingency plan requirements of the Washington Administrative Code, Chapter 173- 303 for certain Resource Conservation and Recovery Act of 1976 waste management units. The 216-U-12 Crib is a landfill that received waste from the 291-U-1 Stack, 244-WR Vault, 244-U via tank C-5, and the UO 3 Plant. The crib pipeline was cut and permanently capped in 1988, and the crib has been backfilled. The unit will be closed under final facility standards. Waste management activities are no longer required at the unit. The crib does not present a significant hazard to adjacent units, personnel, or the environment. It is unlikely that any incidents presenting hazards to public health or the environment would occur at the 216-U-12 Crib

  13. 216-A-36B Crib supplemental information to the Hanford Facility Contingency Plan (DOE/RL-93-75)

    International Nuclear Information System (INIS)

    Ingle, S.J.

    1996-05-01

    This document is a unit-specific contingency plan for the 216-A-36B Crib and is intended to be used as a supplement to DOE/RL-93-75, Hanford Facility Contingency Plan (DOE-RL 1993). This unit-specific plan is to be used to demonstrate compliance with the contingency plan requirements of the Washington Administrative Code, Chapter 173- 303 for certain Resource Conservation and Recovery Act of 1976 waste management units. The 216-A-36B Crib is a landfill that received ammonia scrubber waste from the 202-A Building (Plutonium/Uranium Extraction Plant) between 1966 and 1972. In 1982, the unit was reactivated to receive additional waste from Plutonium/Uranium Extraction operations. Discharges ceased in 1987, and the crib will be closed under final facility standards. Because the crib is not receiving discharges, waste management activities are no longer required. The crib does not present a significant hazard to adjacent units, personnel, or the environment. There is little likelihood that any incidents presenting hazards to public health or the environment would occur at the 216-A-36B Crib

  14. 105-DR Large Sodium Fire Facility Supplemental Information to the Hanford Facility Contingency Plan (DOE/RL-93-75)

    International Nuclear Information System (INIS)

    Edens, V.G.

    1998-05-01

    This document is a unit-specific contingency plan for the 105-DR Large Sodium Fire Facility and is intended to be used as a supplement to DOE/RL-93-75, Hanford Facility Contingency Plan (DOE-RL 1993). This unit-specific plan is to be used to demonstrate compliance with the contingency plan requirements of Washington Administrative Code (WAC) 173-303 for certain Resource Conservation and Recovery Act of 1976 (RCRA) waste management units.The LSFF occupied the former ventilation supply fan room and was established to provide a means of investigating fire and safety aspects associated with large sodium or other metal alkali fires. The unit was used to conduct experiments for studying the behavior of molten alkali metals and alkali metal fires. This unit had also been used for the storage and treatment of alkali metal dangerous waste. Additionally, the Fusion Safety Support Studies programs sponsored intermediate-size safety reaction tests in the LSFF with lithium and lithium-lead compounds. The LSFF, which is a RCRA site, was partially clean closed in 1995 and is documented in 'Transfer of the 105-DR Large Sodium Fire Facility to Bechtel Hanford, Inc.' (BHI 1998). In summary, the 105-DR supply fan room (1720-DR) has been demolished, and a majority of the surrounding soils were clean-closed. The 117-DR Filter Building, 116-DR Exhaust Stack, 119- DR Sampling Building, and associated ducting/tunnels were not covered under this closure

  15. New wheat-rye 5DS-4RS·4RL and 4RS-5DS·5DL translocation lines with powdery mildew resistance.

    Science.gov (United States)

    Fu, Shulan; Ren, Zhenglong; Chen, Xiaoming; Yan, Benju; Tan, Feiquan; Fu, Tihua; Tang, Zongxiang

    2014-11-01

    Powdery mildew is one of the serious diseases of wheat (Triticum aestivum L., 2 n = 6 × = 42, genomes AABBDD). Rye (Secale cereale L., 2 n = 2 × = 14, genome RR) offers a rich reservoir of powdery mildew resistant genes for wheat breeding program. However, extensive use of these resistant genes may render them susceptible to new pathogen races because of co-evolution of host and pathogen. Therefore, the continuous exploration of new powdery mildew resistant genes is important to wheat breeding program. In the present study, we identified several wheat-rye addition lines from the progeny of T. aestivum L. Mianyang11 × S. cereale L. Kustro, i.e., monosomic addition lines of the rye chromosomes 4R and 6R; a disomic addition line of 6R; and monotelosomic or ditelosomic addition lines of the long arms of rye chromosomes 4R (4 RL) and 6R (6 RL). All these lines displayed immunity to powdery mildew. Thus, we concluded that both the 4 RL and 6 RL arms of Kustro contain powdery mildew resistant genes. It is the first time to discover that 4 RL arm carries powdery mildew resistant gene. Additionally, wheat lines containing new wheat-rye translocation chromosomes were also obtained: these lines retained a short arm of wheat chromosome 5D (5 DS) on which rye chromosome 4R was fused through the short arm 4 RS (designated 5 DS-4 RS · 4 RL; 4 RL stands for the long arm of rye chromosome 4R); or they had an extra short arm of rye chromosome 4R (4 RS) that was attached to the short arm of wheat chromosome 5D (5 DS) (designated 4 RS-5 DS · 5 DL; 5 DL stands for the long arm of wheat chromosome 5D). These two translocation chromosomes could be transmitted to next generation stably, and the wheat lines containing 5 DS-4 RS · 4 RL chromosome also displayed immunity to powdery mildew. The materials obtained in this study can be used for wheat powdery mildew resistant breeding program.

  16. Precision of RL/OSL medical dosimetry with fiber-coupled Al2O3:C: Influence of readout delay and temperature variations

    DEFF Research Database (Denmark)

    Andersen, Claus Erik; Morgenthaler Edmund, Jens; Damkjær, Sidsel Marie Skov

    2010-01-01

    Carbon-doped aluminum oxide (Al2O3:C) crystals attached to 15 m optical fiber cables can be used for online in vivo dosimetry during, for example, remotely afterloaded brachytherapy. Radioluminescence (RL) is generated spontaneously in Al2O3:C during irradiation, and this scintillator-like signal...

  17. A Case-Control Study Indicates that no Association Exists Between Polymorphisms of IL-33 and IL-1RL1 and Preeclampsia

    Directory of Open Access Journals (Sweden)

    Xiaoyan Ren

    2016-03-01

    Full Text Available Background/Aims: Preeclampsia (PE is a systemic inflammatory response syndrome involving varieties of cytokines, and previous studies have shown that IL-33 and its receptor IL-1RL1 play pivotal roles in the development of it. As a polygenetic hereditary disease, it is necessary to study the gene analysis for PE. Therefore, the present study was to determine whether IL-33 rs3939286 and IL-1RL1 rs13015714 associated with susceptibility to PE in Chinese Han women. Methods: 1,031 PE patients and 1,298 controls were enrolled and the genotyping for rs3939286 in IL-33 and rs13015714 in IL-1RL1 was performed by TaqMan allelic discrimination real-time PCR. Hardy-Weinberg equilibrium (HWE was examined to ensure the group representativeness and Pearson's chi-square test was used to compare the differences in genetic distributions between the two groups. Results: No significant differences in genotypic and allelic frequencies of the two polymorphisms loci were observed between cases and controls. There were also no significant differences in genetic distributions between mild/severe and early/late-onset PE and control groups. Conclusion: Although our data suggested that the polymorphisms of IL-33 rs3939286 and IL-1RL1 rs13015714 might not be critical risk factors for PE in Chinese Han women, the results need to be validated in different nations.

  18. Verginin Ağırlıklandırılmış Fiyat Elastikiyetinin Hesaplanması: Türkiye (1998-2013

    Directory of Open Access Journals (Sweden)

    Engin YILMAZ

    2015-04-01

    Full Text Available Bu çalışma içerisinde, enflasyonun vergi gelirleri üzerindeki etkilerini inceleyen ilk çalışmalarda ortaya konulan, “gelişmekte olan ülkelerde verginin ağırlıklandırılmış fiyat elastikiyetinin birim olduğu” varsayımı Türkiye için 1998 -2013 periyodu için yeniden değerlendirilecektir. Ağırlıklandırılmış fiyat elastikiyetinin hesaplanmasında Türk vergi gelirleri ve fiyat endeksleri verileri kullanılmıştır. Dinamik En Küçük Kareler (DOLS yöntemiyle, vergi sisteminin uzun dönem ağırlıklandırılmış fiyat elastikiyeti tahmin edilmiştir. Çalışmanın önemi Türkiye için verginin ağırlıklandırılmış fiyat elastikiyetini hesaplamaya yönelik ilk çalışma olmasıdır. Bu anlamda “gelişmekte olan ülkelerde verginin ağırlıklandırılmış fiyat elastikiyetinin birim olduğu” varsayımının yeniden gözden geçirilmesi için yol gösterici bir çalışma olacaktır.

  19. Nonradioactive Dangerous Waste Landfill supplemental information to the Hanford Facility Contingency Plan (DOE/RL-93-75)

    International Nuclear Information System (INIS)

    Ingle, S.J.

    1996-05-01

    This document is a unit-specific contingency plan for the Nonradioactive Dangerous Waste Landfill and is intended to be used as a supplement to DOE/RL-93-75, 'Hanford Facility Contingency Plan.' This unit-specific plan is to be used to demonstrate compliance with the contingency plan requirements of the Washington Administrative Code, Chapter 173-303 for certain Resource, Conservation and Recovery Act of 1976 waste management units. The Nonradioactive Dangerous Waste Landfill (located approximately 3.5 miles southeast of the 200 East Area at the Hanford Site) was used for disposal of nonradioactive dangerous waste from January 1975 to May 1985. Currently, there are no dangerous waste streams disposed in the Nonradioactive Dangerous Waste Landfill. Dangerous waste management activities are no longer required at the landfill. The landfill does not present a significant hazard to adjacent units, personnel, or the environment. It is unlikely that incidents presenting hazards to public health or the environment would occur at the Nonradioactive Dangerous Waste Landfill

  20. Immunologic basis of resistance to rl male 1 induced by immunoselected thy-1.2 negative variants

    International Nuclear Information System (INIS)

    Buxbaum, J.N.; Basch, R.S.

    1980-01-01

    Variant cell lines that have lost the Thy-1 antigen have a reduced capacity to induce tumors in syngeneic recipients when compared to Thy-1 positive clones. The negative variants are cloned, cultured cells obtained from the Thy-1.2(theta) positive BALB/c lymphoma RL male 1 in a single-step immunoselection procedure. The reduction appears to be related to an alteration in the host response to the tumor, since both the variant and parental cells induce tumors equally well in irradiated mice. Males are much more susceptible to the inoculated tumor cells, suggesting that the relevant response is restricted to females. A majority of female animals that survive challenge with the variant do not allow growth of the parental tumor when they are injected with a quantity of cells that is uniformly fatal in untreated recipients. Most of the surviving females have an antibody in their sera that is cytotoxic for the variant, its parent, and normal thymocytes. None of the few surviving males had significant titers of the antibody. Cell-mediated immunity directed toward the positive and negative tumor cells was demonstrable in half the surviving animals of both sexes

  1. Real time dose rate measurements with fiber optic probes based on the RL and OSL of beryllium oxide

    International Nuclear Information System (INIS)

    Teichmann, T.; Sponner, J.; Jakobi, Ch.; Henniger, J.

    2016-01-01

    This work covers the examination of fiber optical probes based on the radioluminescence and real time optically stimulated luminescence of beryllium oxide. Experiments are carried out to determine the fundamental dosimetric and temporal properties of the system and evaluate its suitability for dose rate measurements in brachytherapy and other applications using non-pulsed radiation fields. For this purpose the responses of the radioluminescence and optically stimulated luminescence signal have been investigated in the dose rate range of 20 mGy/h to 3.6 Gy/h and for doses of 1 mGy up to 6 Gy. Furthermore, a new, efficient analysis procedure, the double phase reference summing, is introduced, leading to a real time optically stimulated luminescence signal. This method allows a complete compensation of the stem effect during the measurement. In contrast to previous works, the stimulation of the 1 mm cylindrical beryllium oxide detectors is performed with a symmetric function during irradiation. The investigated dose rates range from 0.3 to 3.6 Gy/h. The real time optically stimulated luminescence signal of beryllium oxide shows a dependency on both the dose rate and the applied dose. To overcome the problem of dose dependency, further experiments using higher stimulation intensities have to follow. - Highlights: • RL and OSL measurements with BeO extended to low dose (rate) range. • A new method to obtain the real time OSL: Dual Phase Reference Summing. • Real time OSL signal shows both dose and dose rate dependency. • Real time OSL enables a complete discrimination of the stem effect.

  2. Richland Operations (DOE-RL) Environmental Safety Health (ES and H) FY 2000 and FY 2001 Execution Commitment Summary

    Energy Technology Data Exchange (ETDEWEB)

    REEP, I.E.

    2000-12-01

    All sites in the U.S. Department of Energy (DOE) Complex prepare this report annually for the DOE Office of Environment, Safety and Health (EH). The purpose of this report is to provide a summary of the previous and current year's Environment, Safety and Health (ES&H) execution commitments and the Safety and Health (S&H) resources that support these activities. The fiscal year (FY) 2000 and 2001 information and data contained in the Richland Operations Environment, Safefy and Health Fiscal Year 2002 Budget-Risk Management Summary (RL 2000a) were the basis for preparing this report. Fiscal year 2001 activities are based on the President's Amended Congressional Budget Request of $689.6 million for funding Ofice of Environmental Management (EM) $44.0 million for Fast Flux Test Facility standby less $7.0 million in anticipated DOE, Headquarters holdbacks for Office of Nuclear Energy, Science and Technology (NE); and $55.3 million for Safeguards and Security (SAS). Any funding changes as a result of the Congressional appropriation process will be reflected in the Fiscal Year 2003 ES&H Budget-Risk Management Summary to be issued in May 2001. This report provides the end-of-year status of FY 2000 ES&H execution commitments, including actual S&H expenditures, and describes planned FY 2001 ES&H execution commitments and the S&H resources needed to support those activities. This requirement is included in the ES&H guidance contained in the FY 2002 Field Budget Call (DOE 2000).

  3. CRA(Crosolic Acid) isolated from Actinidia valvata Dunn.Radix induces apoptosis of human gastric cancer cell line BGC823 in vitro via down-regulation of the NF-κB pathway.

    Science.gov (United States)

    Cheng, Qi-Lai; Li, Hong-Liang; Li, Ying-Chen; Liu, Zhao-Wen; Guo, Xiao-Hua; Cheng, Yi-Jian

    2017-07-01

    A natural ursolic compound, 2α,3β-dihydroxy-urs-12-en-28-oic acid (corosolic acid, CRA) was isolated from the root of Actinidia valvata Dunn. (A. valvata Radix). Since a large number of triterpenoid compound has marked anticancer effects toward various types of cancer cell lines in vitro, this study was carried out to investigate the anticancer effect of CRA in human gastric cancer cell line BGC823 cells and the underlying apoptotic mechanism of CRA was examined in BGC823 cell lines. The results showed that CRA significantly suppressed the viability of BGC823 cells in a concentration- and time-dependent manner. CRA also significantly increased the sub G1 population by cell cycle analysis in a concentration dependent manner. Exposure to CRA decreased p65, bcl-2, Fas, smac mRNA and protein expression, and increased IκBα, bax, survivin mRNA and protein expression. Results of immunofluorescence staining and EMSA further indicated CRA induced apoptosis by inhibiting nuclear translocation of nuclear factor NF-κB subunit p65. Consistently overall, our findings suggest that CRA induces apoptosis via inhibition of NF-κB (p65) expression level and activation of IκBα in BGC cells as a potent anticancer candidate for gastric cancer treatment. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. 7,12-Dimethylbenzanthracene induces apoptosis in RL95-2 human endometrial cancer cells: Ligand-selective activation of cytochrome P450 1B1

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ji Young [Department of Anatomy and Cell Biology, College of Medicine, Dong-A University, Busan 602-714 (Korea, Republic of); Medical Research Science Center, Dong-A University, Busan 602-714 (Korea, Republic of); Lee, Seung Gee [Department of Anatomy and Cell Biology, College of Medicine, Dong-A University, Busan 602-714 (Korea, Republic of); Mitochondria Hub Regulation Center, Dong-A University, Busan 602-714 (Korea, Republic of); Chung, Jin-Yong [Department of Anatomy and Cell Biology, College of Medicine, Dong-A University, Busan 602-714 (Korea, Republic of); Medical Research Science Center, Dong-A University, Busan 602-714 (Korea, Republic of); Kim, Yoon-Jae [Department of Anatomy and Cell Biology, College of Medicine, Dong-A University, Busan 602-714 (Korea, Republic of); Mitochondria Hub Regulation Center, Dong-A University, Busan 602-714 (Korea, Republic of); Park, Ji-Eun [Department of Anatomy and Cell Biology, College of Medicine, Dong-A University, Busan 602-714 (Korea, Republic of); Medical Research Science Center, Dong-A University, Busan 602-714 (Korea, Republic of); Oh, Seunghoon [Department of Physiology, College of Medicine, Dankook University, Cheonan 330-714 (Korea, Republic of); Lee, Se Yong [Department of Obstetrics and Gynecology, Busan Medical Center, Busan 611-072 (Korea, Republic of); Choi, Hong Jo [Department of General Surgery, College of Medicine, Dong-A University, Busan 602-714 (Korea, Republic of); Yoo, Young Hyun, E-mail: yhyoo@dau.ac.kr [Department of Anatomy and Cell Biology, College of Medicine, Dong-A University, Busan 602-714 (Korea, Republic of); Mitochondria Hub Regulation Center, Dong-A University, Busan 602-714 (Korea, Republic of); Medical Research Science Center, Dong-A University, Busan 602-714 (Korea, Republic of); and others

    2012-04-15

    7,12-Dimethylbenzanthracene (DMBA), a polycyclic aromatic hydrocarbon, exhibits mutagenic, carcinogenic, immunosuppressive, and apoptogenic properties in various cell types. To achieve these functions effectively, DMBA is modified to its active form by cytochrome P450 1 (CYP1). Exposure to DMBA causes cytotoxicity-mediated apoptosis in bone marrow B cells and ovarian cells. Although uterine endometrium constitutively expresses CYP1A1 and CYP1B1, their apoptotic role after exposure to DMBA remains to be elucidated. Therefore, we chose RL95-2 endometrial cancer cells as a model system for studying DMBA-induced cytotoxicity and cell death and hypothesized that exposure to DMBA causes apoptosis in this cell type following CYP1A1 and/or CYP1B1 activation. We showed that DMBA-induced apoptosis in RL95-2 cells is associated with activation of caspases. In addition, mitochondrial changes, including decrease in mitochondrial potential and release of mitochondrial cytochrome c into the cytosol, support the hypothesis that a mitochondrial pathway is involved in DMBA-induced apoptosis. Exposure to DMBA upregulated the expression of AhR, Arnt, CYP1A1, and CYP1B1 significantly; this may be necessary for the conversion of DMBA to DMBA-3,4-diol-1,2-epoxide (DMBA-DE). Although both CYP1A1 and CYP1B1 were significantly upregulated by DMBA, only CYP1B1 exhibited activity. Moreover, knockdown of CYP1B1 abolished DMBA-induced apoptosis in RL95-2 cells. Our data show that RL95-2 cells are susceptible to apoptosis by exposure to DMBA and that CYP1B1 plays a pivotal role in DMBA-induced apoptosis in this system. -- Highlights: ► Cytotoxicity-mediated apoptogenic action of DMBA in human endometrial cancer cells. ► Mitochondrial pathway in DMBA-induced apoptosis of RL95-2 endometrial cancer cells. ► Requirement of ligand-selective activation of CYP1B1 in DMBA-induced apoptosis.

  5. Valid measures of periodic leg movements (PLMs) during a suggested immobilization test using the PAM-RL leg activity monitors require adjusting detection parameters for noise and signal in each recording.

    Science.gov (United States)

    Yang, Myung Sung; Montplaisir, Jacques; Desautels, Alex; Winkelman, John W; Cramer Bornemann, Michel A; Earley, Christopher J; Allen, Richard P

    2014-01-01

    Individuals with restless legs syndrome (RLS) (Willis-Ekbom disease [WED]) usually have periodic leg movements (PLMs). The suggested immobilization test (SIT) measures sensory and motor features of WED during wakefulness. Surface electromyogram (EMG) recordings of the anterior tibialis (AT) are used as the standard for counting PLMs. However, due to several limitations, leg activity meters such as the PAM-RL were advanced as a potential substitute. In our study, we assessed the validity of the measurements of PLM during wakefulness (PLMW) in the SIT for PAM-RL using both default and custom detection threshold parameters compared to AT EMG. Data were obtained from 39 participants who were diagnosed with primary WED and who were on stable medication as part of another study using the SIT to repeatedly evaluate WED symptoms over 6-12 months. EMG recordings and PAM-RL, when available, were used to detect PLMW for each SIT. Complete PAM-RL and polysomnography (PSG) EMG data were available for 253 SITs from that study. The default PAM-RL (dPAM-RL) detected leg movements based on manufacturer's noise (resting) and signal (movement) amplitude criteria developed to accurately detect PLM during sleep (PLMS). The custom PAM-RL (cPAM-RL) similarly detected leg movements except the noise and movement detection parameters were adjusted to match the PAM-RL data for each SIT. The distributions of the differences between either dPAM-RL or cPAM-RL and EMG PLMW were strongly leptokurtic (Kurtosis >2) with many small differences and a few unusually large differences. These distributions are better described by median and quartile ranges than mean and standard deviation. Despite an adequate correlation (r=0.66) between the dPAM-RL and EMG recordings, the dPAM-RL on average significantly underscored the number of PLMW (median: quartiles=-13: -51.2, 0.0) and on Bland-Altman plots had a significant magnitude bias with greater underscoring for larger average PLMW/h. There also was an

  6. Microbial analyses of clay and water from different samples from the Mont Terri Rock Laboratory (RL), Switzerland

    International Nuclear Information System (INIS)

    Sergeant, C.; Vesvres, M.H.; Barsotti, V.; Stroes-Gascoyne, S.; Hamon, C.J.; Neble, S.; Shippers, A.; Le Marrec, C.; Vinsot, A.; Schwyn, B.

    2010-01-01

    Document available in extended abstract form only. Exploration of deep subsurface microbial life has increased for very diverse motives. One of them is that these environments are potential host rocks for radioactive waste repositories and that microorganisms may influence geochemical conditions around such sites and migration properties of radionuclides. The pore water Chemistry experiment (PC) was conducted at the Mont Terri-RL to measure in situ the pH, Eh, and other geochemical parameters within the pore water of the Opalinus Clay formation. The borehole for PC was drilled with N 2 under clean but not aseptic conditions, filled immediately with synthetic pore water, which was circulated and monitored for five years. Soon after initiation of PC it was evident that microbial activity affected the borehole water geochemistry. Microbial analyses, including molecular biology and culturing methods, were performed repeatedly during PC (2003-2006), with detailed analysis of water and over-core clay upon termination in 2007. Results indicated the presence of heterotrophic aerobes and anaerobes, nitrate-reducers, iron-reducers, sulphate-reducers and Archaea, which together with geochemical data suggested a reducing environment with sulphate reduction in the water and adjacent clay. A black precipitate containing pyrite and a strong H 2 S smell confirmed the occurrence of sulphate reduction. Specific species identified (> 98% similarity) in PC water included Pseudomonas stutzeri, Bacillus licheniformis, and Desulfosporosinus sp., with similar and additional species (e.g., Trichococcus sp.; Koccuria sp.) in the clay. The origin of these (mostly anaerobic) species cannot be determined with certainty. Some species likely resulted from contamination, but others could be revived species indigenous in the Opalinus Clay. The microbial processes that occurred in PC are not representative of the processes in the undisturbed formation but illustrate the potential for microbial

  7. Cationic PLGA/Eudragit RL nanoparticles for increasing retention time in synovial cavity after intra-articular injection in knee joint

    Directory of Open Access Journals (Sweden)

    Kim SR

    2015-08-01

    Full Text Available Sung Rae Kim,1 Myoung Jin Ho,2 Eugene Lee,3 Joon Woo Lee,3 Young Wook Choi,1 Myung Joo Kang21College of Pharmacy, Chung-Ang University, Dongjak-gu, Seoul, 2College of Pharmacy, Dankook University, Dongnam-gu, Cheonan, Chungnam, 3Department of Radiology, Seoul National University Bundang Hospital, Bundang-gu, Seongnam, Gyeonggi-do, South KoreaAbstract: Positively surface-charged poly(lactide-co-glycolide (PLGA/Eudragit RL nanoparticles (NPs were designed to increase retention time and sustain release profile in joints after intra-articular injection, by forming micrometer-sized electrostatic aggregates with hyaluronic acid, an endogenous anionic polysaccharide found in high amounts in synovial fluid. The cationic NPs consisting of PLGA, Eudragit RL, and polyvinyl alcohol were fabricated by solvent evaporation technique. The NPs were 170.1 nm in size, with a zeta potential of 21.3 mV in phosphate-buffered saline. Hyperspectral imaging (CytoViva® revealed the formation of the micrometer-sized filamentous aggregates upon admixing, due to electrostatic interaction between NPs and the polysaccharides. NPs loaded with a fluorescent probe (1,1'-dioctadecyl-3,3,3',3' tetramethylindotricarbocyanine iodide, DiR displayed a significantly improved retention time in the knee joint, with over 50% preservation of the fluorescent signal 28 days after injection. When DiR solution was injected intra-articularly, the fluorescence levels rapidly decreased to 30% of the initial concentration within 3 days in mice. From these findings, we suggest that PLGA-based cationic NPs could be a promising tool for prolonged delivery of therapeutic agents in joints selectively.Keywords: PLGA, Eudragit RL, hyaluronic acid, cationic nanoparticles, intra-articular injection, electrostatic interaction

  8. Zanaatkârlığın Tarihsel Dönüşümü Ve Richard Sennett’in Zanaatkârlık Kavramı / Historical Transformation of Craftsmanship and Richard Sennett’s Concept of Craftsmanhip

    Directory of Open Access Journals (Sweden)

    Umut Osmanlı

    2017-06-01

    Full Text Available Abstract This study examines the concept of crafting which means becoming an expert in an activity. Specializing in a field, in order to facilitate the life, backs as early as the first human settlements in human history. Crafting is a phenomenon in which the person makes the craft in the best possible way for its own goodness. However, it has been gone through some transformations since its formation. The history of crafting includes some milestones such as institution of crafting, its unification and its transformation after the Industrial Revolution. The most essential one of those transformations has been experienced after the Industrial Revolution and it has become difficult to define the crafting followingly. At the present time, crafting has been diminished to the status of a simple worker. In this work, which the historical transformation of crafting is held, It will be examined respectively: the historical roots of crafting, the social status of crafting, professional organizations that hold crafting altogether, the effects on crafting brought by new economic order of industrial revolution and the ideas of Richard Sennett on crafting in order to evaluate crafting in our present society. Hereby, I will try to reach the definitions of crafting that are able to address our today’s society by taking references from the roots of archaic crafting phenomenon. Öz Bu çalışmada, bilinçli olarak yapılan bir eylemde ustalaşma/uzmanlaşma anlamına gelen zanaatkârlık kavramı incelenmiştir. Hayatı kolaylaştırmak adına herhangi bir alanda çalışma ve bu alanda beceri kazanarak ustalaşmak, insanların bir arada yaşamaya başlaması kadar eskidir. Zanaatkârlık, kişinin kendi iyiliği için uğraş verdiği şeyi mümkün olan en iyi şekilde yapmasıdır. Fakat bu durum ortaya çıktığı günden günümüze gelene kadar çeşitli dönüşümlere uğramıştır. Zanaatkârlığın tarihsel serüveni, zanaatkârl

  9. Flavonoids from Twigs of Millettia leptobotrya Dunn.

    Directory of Open Access Journals (Sweden)

    Zhi Na

    2013-08-01

    Full Text Available A new furanoisoflavone, 2 ' -methoxy-4 ' ,5 ' -methylenedioxy-[2 '' ,3 '' :7,8 ] furanoisoflavone, leptobotryanone ( 1 , and a new natural O-prenylated isoflavone, 4 ' -γ,γ-dimethylallyloxy-5,7-dihydroxyisoflavone ( 2 , were isolated from the twig s of Millettia leptobotrya, together with twelve known flavonoids, 4 ' -γ,γ-dimethylallyloxy-5-hydroxy-7-methoxyisoflavone ( 3 , 2 ' ,6,7-trimethoxy-4 ' ,5 ' -methylenedioxy- isoflavone (4, 2 ' ,7-dimethoxy-4 ' ,5 ' -methylenedioxyisoflavone (5, maximaisoflavone B (6, medicarpin (7 , maackiain (8, genistein (9, biochanin A (10, prunetin (11, chrysoeriol (12 , kaempferol (13 and desmoxyphyllin A (14 The structures of new compounds were elucidated on the basis of spectroscopic data interpretation , including 1D and 2D NMR and HREIMS. Th is is the first phytochemical investigation of this plant.

  10. Waterverdamping uit dunne mest; resultaten van modelberekeningen

    NARCIS (Netherlands)

    Wagenberg, van A.V.; Verdoes, N.; Vranken, E.; Berckmans, D.

    1999-01-01

    In een geïntegreerd luchtbehandelingsysteem kunnen technische oplossingen voor de emissieproblematiek (ammoniak, geur) en de mestproblematiek worden gecombineerd. Door ventilatielucht uit de stal intensief in contact te brengen met mest kan water uit de mest verdampen. Daardoor droogt de mest. Het

  11. Effect of different seawater Mg

    NARCIS (Netherlands)

    Mewes, A.; Langer, G.; de Nooijer, L.J.; Bijma, J.; Reichart, G.J.

    2014-01-01

    Magnesium, incorporated in foraminiferal calcite (Mg/CaCC), is used intensively to reconstruct past seawater temperatures but, in addition to temperature, the Mg/CaCC of foraminiferal tests also depends on the ratio of Mg and Ca in seawater (Mg/CaSW). The physiological mechanisms responsible for

  12. Integration of supercapacitive storage in renewable energy system to compare the response of two level and five level inverter with RL type load

    Science.gov (United States)

    Jana, Suman; Biswas, Pabitra Kumar; Das, Upama

    2018-04-01

    The analytical and simulation-based study in this presented paper shows a comparative report between two level inverter and five-level inverter with the integration of Supercapacitive storage in Renewable Energy system. Sometime dependent numerical models are used to measure the voltage and current response of two level and five level inverter in MATLAB Simulink based environment. In this study supercapacitive sources, which are fed by solar cells are used as input sources to experiment the response of multilevel inverter with integration of su-percapacitor as a storage device of Renewable Energy System. The RL load is used to compute the time response in MATLABSimulink based environment. With the simulation results a comparative study has been made of two different level types of inverters. Two basic types of inverter are discussed in the study with reference to their electrical behavior. It is also simulated that multilevel inverter can convert stored energy within supercapacitor which is extracted from Renewable Energy System.

  13. Production and characterization of compounds based on MgB4O7 for application in dosimetry

    International Nuclear Information System (INIS)

    Souza, Luiza Freire de

    2016-01-01

    Many materials with luminescent properties are used for ionizing radiation dosimetry through the thermoluminescence (TL) and optically stimulated luminescence (OSL) techniques. Detectors based on lithium fluoride (LiF), calcium sulphate (CaSO 4 ) and aluminum oxide (Al 2 O 3 ), doped or codoped with various elements, are the TL or OSL commercial dosimeters most widely used currently. However, several researches are focused to the development of new TL /OSL materials in intention to enhance the dosimetric properties, in view that no TL/OSL dosimeter has all the ideal characteristics for monitoring the radiation. In this context, magnesium tetraborate (MgB 4 O 7 ), which has been presented in the literature as a material for dosimetry TL, was investigated in this work. As there are no reports on the structural characterization of this material or regarding to its applicability on OSL dosimetry, the proposal of the present work was to develop compounds based on MgB 4 O 7 , with different doping, by solid state synthesis. It was made the structural, optical, TL and OSL characterization of the compound to verify it feasibility for application on radiation dosimetry. Initially, it was determined the calcination temperature and time for MgB 4 O 7 formation, with the use of thermal analyses and x ray diffraction. The ideal calcination was found at 900 °C for 7 hours. It were produced , in powder form, the compounds: MgB 4 O 7 , MgB 4 O 7 :Dy, MgB 4 O 7 :Dy,Li, MgB 4 O 7 :Ce, MgB 4 O 7 :Ce,Li, MgB 4 O 7 :Nd and MgB 4 O 7 :Nd,Li. For TL and OSL analyses it were produced pellets sintering at 950 °C for 2 hours. The radioluminescence (RL) analyses of MgB 4 O 7 :Dy and MgB 4 O 7 :Dy,Li shows wavelength emissions at 490, 590, 670 and 760 nm. For MgB 4 O 7 :Ce and MgB 4 O 7 :Ce,Li RL was observed wide emission band in the ultraviolet region. For the MgB 4 O 7 :Nd and MgB 4 O 7 :Nd,Li RL were not observed emission from the ultraviolet to infrared. With the results obtained from

  14. Quasicrystal-reinforced Mg alloys.

    Science.gov (United States)

    Kyun Kim, Young; Tae Kim, Won; Hyang Kim, Do

    2014-04-01

    The formation of the icosahedral phase (I-phase) as a secondary solidification phase in Mg-Zn-Y and Mg-Zn-Al base systems provides useful advantages in designing high performance wrought magnesium alloys. The strengthening in two-phase composites (I-phase + α -Mg) can be explained by dispersion hardening due to the presence of I-phase particles and by the strong bonding property at the I-phase/matrix interface. The presence of an additional secondary solidification phase can further enhance formability and mechanical properties. In Mg-Zn-Y alloys, the co-presence of I and Ca 2 Mg 6 Zn 3 phases by addition of Ca can significantly enhance formability, while in Mg-Zn-Al alloys, the co-presence of the I-phase and Mg 2 Sn phase leads to the enhancement of mechanical properties. Dynamic and static recrystallization are significantly accelerated by addition of Ca in Mg-Zn-Y alloy, resulting in much smaller grain size and more random texture. The high strength of Mg-Zn-Al-Sn alloys is attributed to the presence of finely distributed Mg 2 Sn and I-phase particles embedded in the α -Mg matrix.

  15. Verifica dell'appropriatezza dei ricoveri chirurgici secondo lo strumento RL-PVACE: valutazione economica e organizzativa nell'Azienda Ospedaliera G. Salvini

    Directory of Open Access Journals (Sweden)

    R. Barni

    2003-05-01

    Full Text Available

    Obiettivi: analizzare con lo strumento RL-PVACE l’appropriatezza dei ricoveri ordinari esitati in DRG chirurgici ad alto rischio di inappropriatezza; individuare e valutare economicamente i cambiamenti organizzativi necessari per raggiungere il livello di appropriatezza della circolare regionale 39/SAN.

    Metodi: il disegno dello studio è longitudinale e retrospettivo. È stata analizzata la sola giornata di ammissione di tutti i casi ordinari dimessi nel primo semestre dell’anno 2001, con esclusione dei casi 0- 1 giorno, ed esitati in DRG chirurgici che presentavano una quota di ricoveri ordinari, valutabili con RLPVA, superiore alla soglia di ammissibilità definita nel ddg n° 20180 (2002. I DRG così selezionati sono stati in ordine decrescente di numerosità: 119, 162, 55, 158, 222, 160, 267, 232, 270, 262, 40. Utilizzando i dati della contabilità analitica e ipotizzando lo spostamento in 1^ giornata o in day hospital dei ricoveri ordinari, è stato calcolato il punto di pareggio mediante la break-even analysis.

    Risultati: i dati presentati sono relativi a 845 cartelle cliniche corrispondenti ai DRG selezionati nei Presidi di Garbagnate e Bollate. È stato rilevato un livello assistenziale appropriato nel 38,3% dei casi mentre solo il 3,8% delle ammissioni si è rilevata tempestiva (appropriatezza complessiva 40,9%. Il criterio più adottato per l’attribuzione dell’appropriatezza del livello assistenziale è stato K3 (58,3%, seguito da L4 (20%, K1 (7%; meno frequenti i criteri J6 (3,4%, L3 (3,4%, J6 (3,4%, J4 (2,8%. Gli override sono stati attivati in una quota minoritaria di casi (2,1%. Dal punto di vista economico risulta relativamente conveniente il ricorso alla modalità del “one day surgery”.

    Conclusioni: l’utilizzo del protocollo RL-PVACE è risultato agevole (basso ricorso agli override. Il livello di appropriatezza raggiunto è in

  16. Mechanism of the beneficial effects of ATP-MgCl2 following trauma-hemorrhage and resuscitation: downregulation of inflammatory cytokine (TNF, IL-6) release.

    Science.gov (United States)

    Wang, P; Ba, Z F; Morrison, M H; Ayala, A; Dean, R E; Chaudry, I H

    1992-04-01

    Although ATP-MgCl2 improves hepatocellular function in a nonheparinized model of trauma-hemorrhage and crystalloid resuscitation, it remains unknown whether the beneficial effects of this agent are due to downregulation of the release of the inflammatory cytokines, tumor necrosis factor (TNF), and interleukin-6 (IL-6) under those conditions. To study this, rats underwent a 5-cm laparotomy (i.e., trauma induced) and were bled to and maintained at a mean arterial pressure of 40 mm Hg until 40% of maximum bleedout volume was returned in the form of Ringer's lactate (RL). The animals were then resuscitated with four times the volume of shed blood with RL over 60 min. ATP-MgCl2 (50 mumoles/kg body weight each) or an equivalent volume of normal saline was infused intravenously for 95 min. This infusion was started during the last 15 min of RL resuscitation. Plasma levels of TNF and IL-6 were measured at 1.5 hr after the completion of resuscitation by cytokine-dependent cellular assays. Hepatic blood flow was determined by in vivo indocyanine green clearance (corrected by hepatic extraction ratio for indocyanine green), radioactive microspheres, and [3H]-galactose clearance techniques. The results indicate that the levels of circulating TNF and IL-6 increased significantly in the hemorrhaged-resuscitated animals. ATP-MgCl2 treatment, however, markedly decreased the synthesis and/or release of these cytokines to levels similar to the sham group. The markedly decreased hepatic blood flow (as determined by three different methods) and hepatic extraction ratio for indocyanine green were also restored by ATP-MgCl2 treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

  17. Effects of spray drying conditions on the physicochemical properties of the Tramadol-Hcl microparticles containing Eudragit® RS and RL

    Directory of Open Access Journals (Sweden)

    A S Patel

    2012-01-01

    Full Text Available The preparation of Tramadol-HCL spray-dried microspheres can be affected by the long drug recrystallization time. Polymer type and drug-polymer ratio as well as manufacturing parameters affect the preparation. The purpose of this work was to evaluate the possibility to obtain tramadol spray-dried microspheres using the Eudragit® RS and RL; the influence of the spray-drying parameters on morphology, dimension, and physical stability of microspheres was studied. The effects of matrix composition on microparticle properties were characterized by Laser Light scattering, differential scanning calorimetry (DSC, X-ray diffraction study, FT-infrared and UV-visible spectroscopy. The spray-dried microparticles were evaluated in terms of shape (SEM, size distribution (Laser light scattering method, production yield, drug content, initial drug loding and encapsulation efficiency. The results of X-ray diffraction and thermal analysis reveals the conversion of crystalline drug to amorphous. FTIR analysis confirmed the absence of any drug polymer interaction. The results indicated that the entrapment efficiency (EE, and product yield were depended on polymeric composition and polymeric ratios of the microspheres prepared. Tramadol microspheres based on Eudragit® blend can be prepared by spray-drying and the nebulization parameters do not influence significantly on particle properties.

  18. Ângulo de giro e espaçamento entre carreadores em sistemas autopropelidos de irrigação com o aspersor Plona-RL400 Wetted angle and towpath spacing for traveling gun systems with the Plona-RL400 gun sprinkler model

    Directory of Open Access Journals (Sweden)

    Giuliani do Prado

    2007-08-01

    Full Text Available Valores determinados em laboratório, de vazão, raio de alcance e do perfil radial de aplicação de água do aspersor canhão PLONA-RL400, foram utilizados em simulações digitais da uniformidade de aplicação de água desse aspersor operando, na ausência de ventos, com diferentes ângulos de giro e espaçamentos entre carreadores, em sistemas autopropelidos de irrigação. Os valores simulados de uniformidade de aplicação de água foram apresentados em três grupos distintos, cada um dos quais representando condições operacionais (bocal e pressão que determinam a ocorrência da mesma forma geométrica (I, II ou III do perfil radial adimensional de aplicação de água do aspersor avaliado. Para os perfis do tipo I, II e III, observou-se que espaçamentos de carreadores menores que 50% do diâmetro molhado ou situados entre 80 e 90% do diâmetro molhado proporcionaram os maiores valores de uniformidade. Em todas as formas geométricas do perfil, os melhores valores de uniformidade de aplicação de água foram obtidos com ângulos de giro do aspersor entre 180 e 210º.Values of flow rate, radius of throw and radial precipitation profile obtained in laboratory with the PLONA-RL400 gun sprinkler are presented. These values were used on digital simulations of water application uniformity, under no wind conditions, provided by traveling gun machines operating with this sprinkler under different combinations of wetted angle and towpath spacing. Simulated uniformity values were presented arranged under three different clusters, each one corresponding to a different set of sprinkler operational conditions (nozzle versus service pressure that results on the same geometrical shape (I, II or III of PLONA-RL400 radial precipitation profile. For the three profile shapes, it was observed that towpath spacings shorter than 50% of the sprinkler wetted diameter and on the range between 80 and 90% of the sprinkler wetted diameter provide higher

  19. Myasthenia Gravis (MG): Medical Management

    Science.gov (United States)

    ... take effect, prior to surgery or for myasthenic crisis. However, some people receive regular plasmapheresis or IVIg as a supplement to immunosuppressant drugs. Pregnancy In rare cases, pregnancy appears to trigger the onset of MG. ...

  20. Relationship between QTL for grain shape, grain weight, test weight, milling yield, and plant height in the spring wheat cross RL4452/'AC Domain'.

    Science.gov (United States)

    Cabral, Adrian L; Jordan, Mark C; Larson, Gary; Somers, Daryl J; Humphreys, D Gavin; McCartney, Curt A

    2018-01-01

    Kernel morphology characteristics of wheat are complex and quantitatively inherited. A doubled haploid (DH) population of the cross RL4452/'AC Domain' was used to study the genetic basis of seed shape. Quantitative trait loci (QTL) analyses were conducted on a total of 18 traits: 14 grain shape traits, flour yield (Fyd), and three agronomic traits (Plant height [Plht], 1000 Grain weight [Gwt], Test weight [Twt]), using data from trial locations at Glenlea, Brandon, and Morden in Manitoba, Canada, between 1999 and 2004. Kernel shape was studied through digital image analysis with an Acurum® grain analyzer. Plht, Gwt, Twt, Fyd, and grain shape QTL were correlated with each other and QTL analysis revealed that QTL for these traits often mapped to the same genetic locations. The most significant QTL for the grain shape traits were located on chromosomes 4B and 4D, each accounting for up to 24.4% and 53.3% of the total phenotypic variation, respectively. In addition, the most significant QTL for Plht, Gwt, and Twt were all detected on chromosome 4D at the Rht-D1 locus. Rht-D1b decreased Plht, Gwt, Twt, and kernel width relative to the Rht-D1a allele. A narrow genetic interval on chromosome 4B contained significant QTL for grain shape, Gwt, and Plht. The 'AC Domain' allele reduced Plht, Gwt, kernel length and width traits, but had no detectable effect on Twt. The data indicated that this variation was inconsistent with segregation at Rht-B1. Numerous QTL were identified that control these traits in this population.

  1. Relationship between QTL for grain shape, grain weight, test weight, milling yield, and plant height in the spring wheat cross RL4452/‘AC Domain’

    Science.gov (United States)

    Cabral, Adrian L.; Jordan, Mark C.; Larson, Gary; Somers, Daryl J.; Humphreys, D. Gavin

    2018-01-01

    Kernel morphology characteristics of wheat are complex and quantitatively inherited. A doubled haploid (DH) population of the cross RL4452/‘AC Domain’ was used to study the genetic basis of seed shape. Quantitative trait loci (QTL) analyses were conducted on a total of 18 traits: 14 grain shape traits, flour yield (Fyd), and three agronomic traits (Plant height [Plht], 1000 Grain weight [Gwt], Test weight [Twt]), using data from trial locations at Glenlea, Brandon, and Morden in Manitoba, Canada, between 1999 and 2004. Kernel shape was studied through digital image analysis with an Acurum® grain analyzer. Plht, Gwt, Twt, Fyd, and grain shape QTL were correlated with each other and QTL analysis revealed that QTL for these traits often mapped to the same genetic locations. The most significant QTL for the grain shape traits were located on chromosomes 4B and 4D, each accounting for up to 24.4% and 53.3% of the total phenotypic variation, respectively. In addition, the most significant QTL for Plht, Gwt, and Twt were all detected on chromosome 4D at the Rht-D1 locus. Rht-D1b decreased Plht, Gwt, Twt, and kernel width relative to the Rht-D1a allele. A narrow genetic interval on chromosome 4B contained significant QTL for grain shape, Gwt, and Plht. The ‘AC Domain’ allele reduced Plht, Gwt, kernel length and width traits, but had no detectable effect on Twt. The data indicated that this variation was inconsistent with segregation at Rht-B1. Numerous QTL were identified that control these traits in this population. PMID:29357369

  2. Rapid screening of transferrin-binders in the flowers of Bauhinia blakeana Dunn by on-line high-performance liquid chromatography-diode-array detector-electrospray ionization-ion-trap-time-of-flight-mass spectrometry-transferrin-fluorescence detection system.

    Science.gov (United States)

    Liu, Meixian; Dong, Jing; Lin, Zongtao; Niu, Yanyan; Zhang, Xiaotian; Jiang, Haixiu; Guo, Ning; Li, Wei; Wang, Hong; Chen, Shizhong

    2016-06-10

    Transferrin (Transferrin, TRF, TF) has drawn increasing attention in cancer therapy due to its potential applications in drug delivery. TF receptor, highly expressed in tumor cells, recognizes and transports Fe(3+)-TF into cells to release iron into cytoplasm. Thus, discovering TF-binding compounds has become an active research area and is of great importance for target therapy. In this study, an on-line analysis method was established for screening TF-binding compounds from the flowers of Bauhinia blakeana Dunn using a high-performance liquid chromatography-diode-array detector-multi-stage mass spectrometry-transferrin-fluorescence detector (HPLC-DAD-MS(n)-TF-FLD) method. As a result, 33 of 80 identified or tentatively characterized compounds in the sample were TF-binding active. Twenty-five flavonol glycosides and eight phenolic acids were identified as TF-binders. Twelve of these active compounds together with six standard compounds were used to study the dose-response effects and structure-activity relationships of flavonoids and phenolic acids. The method was validated by vitexin with a good linearity in the range of concentrations used in the study. The limit of detection for vitexin was 0.1596 nmol. Our study indicated that the established method is simple, rapid and sensitive for screening TF-binding active compounds in the extract of Bauhinia blakeana Dunn, and therefore is important for discovering potential anti-cancer ingredients from complex samples for TF related drug delivery. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Türkiye'nin 7 akarsu havzasında horozbina, Salaria fluviatilis (Asso,1801, balığına ait boy-ağırlık ilişkisi.

    Directory of Open Access Journals (Sweden)

    Ali İlhan

    2015-12-01

    Full Text Available Bu çalışmada Türkiye‟nin 7 akarsu havzasından toplanmış olan Horozbina Balığı (Salaria fluviatilis‟na ait boy-ağırlık ilişkisinin ortaya çıkarılması amaçlanmıştır. Marmara, Küçük Menderes, Batı Karadeniz, Antalya, Doğu Akdeniz, Seyhan ve Ceyhan havzalarına ait akarsulardan toplanmış olan 652 birey incelenmiştir. Tüm bireyler dikkate alındığında türün Türkiye içsularındaki total boy dağılımı 2.0-12.9 cm, total ağırlık dağılımı 0.10-33.82 g, boy-ağırlık ilişkisi parametreleri a= 0.0135, b= 3.004, r2= 0.986 olarak hesaplanmıştır. Ayrıca, büyüme tipi havzaların 5‟inde izometrik, 1 havzada pozitif allometrik ve 1 havzada da negatif allometrik olarak belirlenmiştir

  4. Anayasa Mahkemesi ve Avrupa İnsan Hakları Mahkemesi Kararlarına Göre İfade Özgürlüğünün Sınırlanması

    OpenAIRE

    ÇAMAK, Sultan

    2016-01-01

    Sağlıklı bir toplum ve devlet yapısının oluşturulması için ifade özgürlüğünün sağlanması esastır. Toplumsal yaşamın sonucu olarak bireyler arasında yaşanan menfaat çatışmalarında dengenin sağlanması amacıyla ifade özgürlüğünün dahi sınırlanabileceği genel olarak hukuk sistemlerinde kabul görmektedir. Temel hak ve özgürlüklerin uluslararası alanda korunması anlamında en önemli belge sayılabilecek Avrupa İnsan Hakları Sözleşmesi’nde de sınırlamanın meşru sayıldığı haller düzenlenmiştir. Bu sebe...

  5. The validity of the PAM-RL device for evaluating periodic limb movements in sleep and an investigation on night-to-night variability of periodic limb movements during sleep in patients with restless legs syndrome or periodic limb movement disorder using this system.

    Science.gov (United States)

    Kobayashi, Mina; Namba, Kazuyoshi; Ito, Eiki; Nishida, Shingo; Nakamura, Masaki; Ueki, Yoichiro; Furudate, Naomichi; Kagimura, Tatsuo; Usui, Akira; Inoue, Yuichi

    2014-01-01

    The status of night-to-night variability for periodic limb movements in sleep (PLMS) has not been clarified. With this in mind, we investigated the validity of PLMS measurement by actigraphy with the PAM-RL device in Japanese patients with suspected restless legs syndrome (RLS) or periodic limb movement disorder (PLMD) and the night-to-night variability of PLMS among the subjects. Forty-one subjects (mean age, 52.1±16.1 years) underwent polysomnography (PSG) and PAM-RL measurement simultaneously. Thereafter, subjects used the PAM-RL at home on four more consecutive nights. The correlation between PLMS index on PSG (PLMSI-PSG) and PLM index on PAM-RL (PLMI-PAM) was 0.781 (PPAM-RL. PAM-RL is thought to be valuable for assessing PLMS even in Japanese subjects. Recording of PAM-RL for three or more consecutive nights may be required to ensure the screening reliability of a patient with suspected pathologically frequent PLMS. Copyright © 2013 Elsevier B.V. All rights reserved.

  6. Privacy preserving probabilistic record linkage (P3RL): a novel method for linking existing health-related data and maintaining participant confidentiality.

    Science.gov (United States)

    Schmidlin, Kurt; Clough-Gorr, Kerri M; Spoerri, Adrian

    2015-05-30

    Record linkage of existing individual health care data is an efficient way to answer important epidemiological research questions. Reuse of individual health-related data faces several problems: Either a unique personal identifier, like social security number, is not available or non-unique person identifiable information, like names, are privacy protected and cannot be accessed. A solution to protect privacy in probabilistic record linkages is to encrypt these sensitive information. Unfortunately, encrypted hash codes of two names differ completely if the plain names differ only by a single character. Therefore, standard encryption methods cannot be applied. To overcome these challenges, we developed the Privacy Preserving Probabilistic Record Linkage (P3RL) method. In this Privacy Preserving Probabilistic Record Linkage method we apply a three-party protocol, with two sites collecting individual data and an independent trusted linkage center as the third partner. Our method consists of three main steps: pre-processing, encryption and probabilistic record linkage. Data pre-processing and encryption are done at the sites by local personnel. To guarantee similar quality and format of variables and identical encryption procedure at each site, the linkage center generates semi-automated pre-processing and encryption templates. To retrieve information (i.e. data structure) for the creation of templates without ever accessing plain person identifiable information, we introduced a novel method of data masking. Sensitive string variables are encrypted using Bloom filters, which enables calculation of similarity coefficients. For date variables, we developed special encryption procedures to handle the most common date errors. The linkage center performs probabilistic record linkage with encrypted person identifiable information and plain non-sensitive variables. In this paper we describe step by step how to link existing health-related data using encryption methods to

  7. Rapid degradation of azo dye Direct Black BN by magnetic MgFe{sub 2}O{sub 4}-SiC under microwave radiation

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Jia; Yang, Shaogui, E-mail: yangsg@nju.edu.cn; Li, Na; Meng, Lingjun; Wang, Fei; He, Huan; Sun, Cheng

    2016-08-30

    Highlights: • MgFe{sub 2}O{sub 4}-SiC was first successfully synthesized. • MgFe{sub 2}O{sub 4}-SiC attained the maximum absorbing value of 13.32 dB at 2.57 GHz, which reached extremely high RL value at low frequency range. • Fast decolorization and high TOC removal of azo dye Direct Black BN with complicated structure could occur with MgFe{sub 2}O{sub 4}-SiC under MW radiation. • MgFe{sub 2}O{sub 4}-SiC had better MW absorbing property and higher MW catalytic activity than MnFe{sub 2}O{sub 4}-SiC under the same condition. • MgFe{sub 2}O{sub 4}-SiC was of practical use in the wastewater treatment. - Abstract: A novel microwave (MW) catalyst, MgFe{sub 2}O{sub 4} loaded on SiC (MgFe{sub 2}O{sub 4}-SiC), was successfully synthesized by sol-gel method, and pure MgFe{sub 2}O{sub 4} was used as reference. The MgFe{sub 2}O{sub 4} and MgFe{sub 2}O{sub 4}-SiC catalysts were characterized by X-ray diffraction (XRD), Scanning electron microscopy (SEM), Transmission electron microscopy (TEM), N{sub 2} adsorption analyzer (BET specific surface area), X-ray photoelectron spectroscopy (XPS). The electromagnetic parameters of the prepared catalysts were measured by vector network analyzer. The reflection loss (RL) based on the electromagnetic parameters calculated in Matlab showed MgFe{sub 2}O{sub 4}-SiC attained the maximum absorbing value of 13.32 dB at 2.57 GHz, which reached extremely high RL value at low frequency range, revealing the excellent MW absorption property of MgFe{sub 2}O{sub 4}-SiC. MW-induced degradation of Direct Black BN (DB BN) over as-synthesized MgFe{sub 2}O{sub 4}-SiC indicated that degradation efficiency of DB BN (20 mg L{sup −1}) in 5 min reached 96.5%, the corresponding TOC removal was 65%, and the toxicity of DB BN after degradation by MgFe{sub 2}O{sub 4}-SiC obviously decreased. The good stability and applicability of MgFe{sub 2}O{sub 4}-SiC on the degradation process were also discovered. Moreover, the ionic chromatogram during degradation

  8. Production and characterization of compounds based on MgB{sub 4}O{sub 7} for application in dosimetry; Producao e caracterizacao de compostos a base de MgB{sub 4}O{sub 7} para aplicacao em dosimetria

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Luiza Freire de

    2016-07-01

    Many materials with luminescent properties are used for ionizing radiation dosimetry through the thermoluminescence (TL) and optically stimulated luminescence (OSL) techniques. Detectors based on lithium fluoride (LiF), calcium sulphate (CaSO{sub 4}) and aluminum oxide (Al{sub 2}O{sub 3}), doped or codoped with various elements, are the TL or OSL commercial dosimeters most widely used currently. However, several researches are focused to the development of new TL /OSL materials in intention to enhance the dosimetric properties, in view that no TL/OSL dosimeter has all the ideal characteristics for monitoring the radiation. In this context, magnesium tetraborate (MgB{sub 4}O{sub 7}), which has been presented in the literature as a material for dosimetry TL, was investigated in this work. As there are no reports on the structural characterization of this material or regarding to its applicability on OSL dosimetry, the proposal of the present work was to develop compounds based on MgB{sub 4}O{sub 7}, with different doping, by solid state synthesis. It was made the structural, optical, TL and OSL characterization of the compound to verify it feasibility for application on radiation dosimetry. Initially, it was determined the calcination temperature and time for MgB{sub 4}O{sub 7} formation, with the use of thermal analyses and x ray diffraction. The ideal calcination was found at 900 °C for 7 hours. It were produced , in powder form, the compounds: MgB{sub 4}O{sub 7}, MgB{sub 4}O{sub 7}:Dy, MgB{sub 4}O{sub 7}:Dy,Li, MgB{sub 4}O{sub 7}:Ce, MgB{sub 4}O{sub 7}:Ce,Li, MgB{sub 4}O{sub 7}:Nd and MgB{sub 4}O{sub 7}:Nd,Li. For TL and OSL analyses it were produced pellets sintering at 950 °C for 2 hours. The radioluminescence (RL) analyses of MgB{sub 4}O{sub 7}:Dy and MgB{sub 4}O{sub 7}:Dy,Li shows wavelength emissions at 490, 590, 670 and 760 nm. For MgB{sub 4}O{sub 7}:Ce and MgB{sub 4}O{sub 7}:Ce,Li RL was observed wide emission band in the ultraviolet region. For the Mg

  9. A biallelic RFLP of the human. alpha. 2-C4 adrenergic receptor gene (ADRA2RL2) localized on the short arm of chromosome 4 and encoding the putative. alpha. 2B receptor is identified with Bsu 36 L using a 1. 5 kb probe (p ADRA2RL2)

    Energy Technology Data Exchange (ETDEWEB)

    Hoeche, M.R.; Berrettini, W.H. (Clinical Neurogenetics Branch, Bethesda, MD (USA)); Regan, J.W. (Duke Univ. Medical Center, Durham, NC (USA))

    1989-12-11

    A 1.5 kb Eco RI cDNA fragment representing the human alpha2-C4 adrenergic receptor (AR) gene encoding the putative alpha2B-AR, containing approximately 1270 bp of the coding and 240 bp of the 3{prime}flanking region, inserted into pSP65, was used as a probe (p ADRA2RL2). This clone was obtained by screening a human kidney lambda GT10 cDNA library with the 0.95 kb Pst I restriction fragment derived from the coding block of the gene for the human platelet alpha2-AR. Hybridization of human genomic DNA digested with Bsu 36 I identifies a two allele polymorphism with bands at 12 kb and 5.8 kb. 20 unrelated North American caucasian subjects were evaluated with frequencies of: A allele, 0.45; B allele, 0.55, heterozygosity (obs), 0.5. This alpha2-AR gene has been mapped in a separation effort in 59 CEPH reference pedigrees to the tip of the short arm of chromosome 4 just proximal to GB (4p 16.3) reported to be linked to the Huntingston's disease gene. Codominant inheritance was observed in seven families with two and three generations, respectively. The number of meioses scored was 95.

  10. A Leu to Ile but not Leu to Val change at HIV-1 reverse transcriptase codon 74 in the background of K65R mutation leads to an increased processivity of K65R+L74I enzyme and a replication competent virus

    Directory of Open Access Journals (Sweden)

    Crumpacker Clyde S

    2011-01-01

    Full Text Available Abstract Background The major hurdle in the treatment of Human Immunodeficiency virus type 1 (HIV-1 includes the development of drug resistance-associated mutations in the target regions of the virus. Since reverse transcriptase (RT is essential for HIV-1 replication, several nucleoside analogues have been developed to target RT of the virus. Clinical studies have shown that mutations at RT codon 65 and 74 which are located in β3-β4 linkage group of finger sub-domain of RT are selected during treatment with several RT inhibitors, including didanosine, deoxycytidine, abacavir and tenofovir. Interestingly, the co-selection of K65R and L74V is rare in clinical settings. We have previously shown that K65R and L74V are incompatible and a R→K reversion occurs at codon 65 during replication of the virus. Analysis of the HIV resistance database has revealed that similar to K65R+L74V, the double mutant K65R+L74I is also rare. We sought to compare the impact of L→V versus L→I change at codon 74 in the background of K65R mutation, on the replication of doubly mutant viruses. Methods Proviral clones containing K65R, L74V, L74I, K65R+L74V and K65R+L74I RT mutations were created in pNL4-3 backbone and viruses were produced in 293T cells. Replication efficiencies of all the viruses were compared in peripheral blood mononuclear (PBM cells in the absence of selection pressure. Replication capacity (RC of mutant viruses in relation to wild type was calculated on the basis of antigen p24 production and RT activity, and paired analysis by student t-test was performed among RCs of doubly mutant viruses. Reversion at RT codons 65 and 74 was monitored during replication in PBM cells. In vitro processivity of mutant RTs was measured to analyze the impact of amino acid changes at RT codon 74. Results Replication kinetics plot showed that all of the mutant viruses were attenuated as compared to wild type (WT virus. Although attenuated in comparison to WT virus

  11. Fine-mapping of qRL6.1, a major QTL for root length of rice seedlings grown under a wide range of NH4+ concentrations in hydroponic conditions

    Science.gov (United States)

    Tamura, Wataru; Ebitani, Takeshi; Yano, Masahiro; Sato, Tadashi; Yamaya, Tomoyuki

    2010-01-01

    Root system development is an important target for improving yield in cereal crops. Active root systems that can take up nutrients more efficiently are essential for enhancing grain yield. In this study, we attempted to identify quantitative trait loci (QTL) involved in root system development by measuring root length of rice seedlings grown in hydroponic culture. Reliable growth conditions for estimating the root length were first established to renew nutrient solutions daily and supply NH4+ as a single nitrogen source. Thirty-eight chromosome segment substitution lines derived from a cross between ‘Koshihikari’, a japonica variety, and ‘Kasalath’, an indica variety, were used to detect QTL for seminal root length of seedlings grown in 5 or 500 μM NH4+. Eight chromosomal regions were found to be involved in root elongation. Among them, the most effective QTL was detected on a ‘Kasalath’ segment of SL-218, which was localized to the long-arm of chromosome 6. The ‘Kasalath’ allele at this QTL, qRL6.1, greatly promoted root elongation under all NH4+ concentrations tested. The genetic effect of this QTL was confirmed by analysis of the near-isogenic line (NIL) qRL6.1. The seminal root length of the NIL was 13.5–21.1% longer than that of ‘Koshihikari’ under different NH4+ concentrations. Toward our goal of applying qRL6.1 in a molecular breeding program to enhance rice yield, a candidate genomic region of qRL6.1 was delimited within a 337 kb region in the ‘Nipponbare’ genome by means of progeny testing of F2 plants/F3 lines derived from a cross between SL-218 and ‘Koshihikari’. Electronic supplementary material The online version of this article (doi:10.1007/s00122-010-1328-3) contains supplementary material, which is available to authorized users. PMID:20390245

  12. Preparation and Hydrogen Storage Properties of Mg-Rich Mg-Ni Ultrafine Particles

    Directory of Open Access Journals (Sweden)

    Jianxin Zou

    2012-01-01

    Full Text Available In the present work, Mg-rich Mg-Ni ultrafine powders were prepared through an arc plasma method. The phase components, microstructure, and hydrogen storage properties of the powders were carefully investigated. It is found that Mg2Ni and MgNi2 could be obtained directly from the vapor state reactions between Mg and Ni, depending on the local vapor content in the reaction chamber. A nanostructured MgH2 + Mg2NiH4 hydrogen storage composite could be generated after hydrogenation of the Mg-Ni ultrafine powders. After dehydrogenation, MgH2 and Mg2NiH4 decomposed into nanograined Mg and Mg2Ni, respectively. Thermogravimetry/differential scanning calorimetry (TG/DSC analyses showed that Mg2NiH4 phase may play a catalytic role in the dehydriding process of the hydrogenated Mg ultrafine particles.

  13. Alterations of Mg2+ After Hemorrhagic Shock.

    Science.gov (United States)

    Lee, Mun-Young; Yang, Dong Kwon; Kim, Shang-Jin

    2017-11-01

    Hemorrhagic shock is generally characterized by hemodynamic instability with cellular hypoxia and diminishing cellular function, resulting from an imbalance between systemic oxygen delivery and consumption and redistribution of fluid and electrolytes. Magnesium (Mg) is the fourth most abundant cation overall and second most abundant intracellular cation in the body and an essential cofactor for the energy production and cellular metabolism. Data for blood total Mg (tMg; free-ionized, protein-bound, and anion-bound forms) and free Mg 2+ levels after a traumatic injury are inconsistent and only limited information is available on hemorrhagic effects on free Mg 2+ as the physiologically active form. The aim of this study was to determine changes in blood Mg 2+ and tMg after hemorrhage in rats identifying mechanism and origin of the changes in blood Mg 2+ . Hemorrhagic shock produced significant increases in blood Mg 2+ , plasma tMg, Na + , K + , Cl - , anion gap, partial pressures of oxygen, glucose, and blood urea nitrogen but significant decreases in RBC tMg, blood Ca 2+ , HCO 3 - , pH, partial pressures of carbon dioxide, hematocrit, hemoglobin, total cholesterol, and plasma/RBC ATP. During hemorrhagic shock, K + , anion gap, and BUN showed significant positive correlations with changes in blood Mg 2+ level, while Ca 2+ , pH, and T-CHO correlated to Mg 2+ in a negative manner. In conclusion, hemorrhagic shock induced an increase in both blood-free Mg 2+ and tMg, resulted from Mg 2+ efflux from metabolic damaged cell with acidosis and ATP depletion.

  14. MAGIICAT II. GENERAL CHARACTERISTICS OF THE Mg II ABSORBING CIRCUMGALACTIC MEDIUM

    Energy Technology Data Exchange (ETDEWEB)

    Nielsen, Nikole M.; Churchill, Christopher W. [New Mexico State University, Las Cruces, NM 88003 (United States); Kacprzak, Glenn G., E-mail: nnielsen@nmsu.edu, E-mail: cwc@nmsu.edu, E-mail: gkacprzak@astro.swin.edu.au [Swinburne University of Technology, Victoria 3122 (Australia)

    2013-10-20

    We examine the Mg II absorbing circumgalactic medium (CGM) for the 182 intermediate redshift (0.072 ≤ z ≤ 1.120) galaxies in the 'Mg II Absorber-Galaxy Catalog' (MAGIICAT). We parameterize the anti-correlation between equivalent width, W{sub r} (2796), and impact parameter, D, with a log-linear fit, and show that a power law poorly describes the data. We find that higher luminosity galaxies have larger W{sub r} (2796) at larger D (4.3σ). The covering fractions, f{sub c} , decrease with increasing D and W{sub r} (2796) detection threshold. Higher luminosity galaxies have larger f{sub c} ; no absorption is detected in lower luminosity galaxies beyond 100 kpc. Bluer and redder galaxies have similar f{sub c} for D < 100 kpc, but for D > 100 kpc, bluer galaxies have larger f{sub c} , as do higher redshift galaxies. The 'absorption radius', R(L) = R{sub *}(L/L*){sup β}, which we examine for four different W{sub r} (2796) detection thresholds, is more luminosity sensitive to the B-band than the K-band, more sensitive for redder galaxies than for bluer galaxies, and does not evolve with redshift for the K-band, but becomes more luminosity sensitive toward lower redshift for the B-band. These trends clearly indicate a more extended Mg II absorbing CGM around higher luminosity, bluer, and higher redshift galaxies. Several of our findings are in conflict with other works. We address these conflicts and discuss the implications of our results for the low-ionization, intermediate redshift CGM.

  15. Modeling and stabilities of Mg/MgH2 interfaces: A first-principles investigation

    Directory of Open Access Journals (Sweden)

    Jia-Jun Tang

    2014-07-01

    Full Text Available We have theoretically investigated the modeling and the structural stabilities of various Mg/MgH2 interfaces, i.e. Mg(101¯0/MgH2(210, Mg(0001/MgH2(101 and Mg(101¯0/MgH2(101, and provided illuminating insights into Mg/MgH2 interface. Specifically, the main factors, which impact the interfacial energies, are fully considered, including surface energies of two phases, mutual lattice constants of interface model, and relative position of two phases. The surface energies of Mg and MgH2, on the one hand, are found to be greatly impacting the interfacial energies, reflected by the lowest interfacial energy of Mg(0001/MgH2(101 which is comprised of two lowest energy surfaces. On the other hand, it is demonstrated that the mutual lattice constants and the relative position of two phases lead to variations of interfacial energies, thus influencing the interface stabilities dramatically. Moreover, the Mg-H bonding at interface is found to be the determinant of Mg/MgH2 interface stability. Lastly, interfacial and strain effects on defect formations are also studied, both of which are highly facilitating the defect formations. Our results provide a detailed insight into Mg/MgH2 interface structures and the corresponding stabilities.

  16. Arnavutluk'ta Enver Hoca Dönemi İnsan Hakları ve Özgürlükler(1945-1985 Humanrights and Freedom in Albania Under Enver Hoxha Period(1945-1985

    Directory of Open Access Journals (Sweden)

    Ali ÖZKAN

    2012-09-01

    Full Text Available Human rights are the basic rights of people which have been born from the first days of humanity. According to Jean Jacques Rousseua, getting read of freedom means getting read of all values of humanbeings. It is almost imposible to think this kind of giving up of human rights and freedom. The Universal Declaration of Human Rights and the EuroeanConvention on Human Rights both generally comprises rights andfreedom, prohibition of torture, slavery, forced labor, freedom, the rightto a fair tail, legal penalties, private and family life, freedom of opinion,speech, religio and conscrence.In this essay, Enver Hoxha was subjected to value himself and hisperiod on ten different areas of human rights and freedom. Comperingthe human rights and freedom of Enver Hoxha’s to the other Balkanand Eastern European States, it is seen that there is a little e diferenceat that time.Enver Hoxha rescued his country from the invaderes country andruled it forty years without any gap. What makes different is that EnverHoca never accepts human rights and freedom although he was themost educated and enlightened man among the dictatorships in theworld at that time. The main reason of this is that Enver Hoca wants tolimit the human rights and freedom or to control all these rights.Additionally, it is well known that Markist Leninist İdeology andStalinist Opinion is a kind of structure in which you can not findfreedom and human rights. İnsan hakları insanlık tarihinin başlamasıyla birlikte doğan ve insanlığın gelişimiyle birlikte ilerleme gösteren en temel haklardır. Jean Jacques Rousseau’ya göre, insan için hürriyetinden vazgeçmek, insanlık sıfatından, insanlığın haklarından hatta görevlerinden vazgeçmek demektir. Böyle bir vazgeçmenin insan tabiatı ile bağdaşması mümkün değildir İnsan Hakları Evrensel Bildirisi ve Avrupa İnsan Hakları Sözleşmesi genel olarak haklar ve özgürlükler, işkence yasağı, kölelilik ve zorla

  17. “Mücadele ve Direnişin” cesur ajanı Ken Loach’un sinemasında insanın “Özgürleşme” sorunu: Psikanalitik yöntemle “Ülke ve Özgürlük” filmi analizi

    OpenAIRE

    Kaplan, Neşe; Kaplan, Ali Barış

    2011-01-01

    Bu çalışmada amacımız, Ken Loach Sinemasının genel özelliklerini ortaya koymak ve spesifik olarak “Ülke ve özgürlük” filmini psikanalitik yöntemle analiz etmektir. Filmlerinde, “Sınıf mücadelesi” ve “bireysel özgürlük” sorununu tartışan Ken Loach, “Ülke ve özgürlük” filmi ile esasen globalleşme süreci içindeki Modern toplumu eleştirmektedir. Yakın geçmişin hikayesini anlatan film, nostaljik değildir; bugüne de mesajı olan dinamik bir anlatı sunar....

  18. Çokkültürlülük ve Yurtseverlik Bağlamında Azınlık Öğrencilerinin Tarih Dersleriyle İlgili Algıları

    Directory of Open Access Journals (Sweden)

    Fatih YAZICI

    2015-10-01

    Full Text Available Bu araştırmada, Türkiye’deki azınlık okullarına devam eden lise öğrencilerinin tarih dersleriyle ilgili görüşlerinin çokkültürlülük ve yurtseverlik bağlamında değerlendirilmesi amaçlanmıştır. Araştırmanın çalışma grubunu kasti örneklem yöntemiyle seçilen, İstanbul’un çeşitli ilçelerindeki azınlık okulunda öğrenim gören 199 öğrenci oluşturmaktadır. Bu çalışma grubundan veri toplamak amacıyla araştırmacılar tarafından geliştirilen Çokkültürlülük Tutum Ölçeği, Yurtseverlik Ölçeği ve tarih derslerini kendi kimlikleri açısından değerlendirmelerini amaçlayan bir anket uygulanmıştır. Verilerin analizinde aritmetik ortalama, standart sapma ve t-testi kullanılmıştır. Araştırmaya katılan öğrencilerin çoğunluğu tarih derslerinde kendi kültürel kimliklerinin yeterince yer bulamadığını, bu kimliklere yer veren bölümlerde ise ötekileştirici bir söylemin kullanıldığını belirtmişlerdir. Tarih dersleri, kültürel farklılığa sahip öğrenciler için bu şekliyle, yurtseverlik duygusu oluşturmanın uzağında kalmaktadır.Anahtar Kelimeler: Tarih Öğretimi, Çokkültürlülük, Yurtseverlik, Çokkültürlü Eğitim, Azınlık Okulları PERCEPTION of MINORITY STUDENTS about HISTORY LESSONS in the CONTEXT of MULTICULTURALISM and PATRIOTISMAbstract: The purpose of this study is to evaluate perceptions of students who attend minority school with respect to history lessons in the context of multiculturalism and patriotism in Turkey. The study group consists of intentionally chosen 199 students attending at different minority schools in Istanbul. Survey method was used in this study. The Multiculturalism Attitude Scale, Patriotism Scale and a questionnaire, developed by the researchers, examining cultural diversity in history lessons were used. In analyzing date, t- test, arithmetic mean and standard deviation were used. The findings of the study indicated

  19. Propuesta para el análisis financiero por medio de la aplicación de indicadores financieros para la toma de decisiones gerenciales de la Cooperativa Coopeacosta R.L.

    OpenAIRE

    Fallas Calderón, Fernando de Jesús

    2014-01-01

    Tesis de maestría -- Universidad de Costa Rica. Posgrado en Administración y Dirección de Empresas. Maestría Profesional en Administración y Dirección de Empresas con énfasis en Finanzas, 2014 Contar con una buena gestión para el manejo de los recursos financieros es un aspecto fundamental para COOPEACOSTA R.L., esto se debe a que su operación gira en torno al manejo financiero de los recursos de los asociados. De ahí el interés por contar con un proceso bien diseñado que vaya dirigido a m...

  20. Transformation of Mg-bearing amorphous calcium carbonate to Mg-calcite - In situ monitoring

    Science.gov (United States)

    Purgstaller, Bettina; Mavromatis, Vasileios; Immenhauser, Adrian; Dietzel, Martin

    2016-02-01

    The formation of Mg-bearing calcite via an amorphous precursor is a poorly understood process that is of relevance for biogenic and abiogenic carbonate precipitation. In order to gain an improved insight on the controls of Mg incorporation in calcite formed via an Mg-rich amorphous calcium carbonate (Mg-ACC) precursor, the precipitation of Mg-ACC and its transformation to Mg-calcite was monitored by in situ Raman spectroscopy. The experiments were performed at 25.0 ± 0.03 °C and pH 8.3 ± 0.1 and revealed two distinct pathways of Mg-calcite formation: (i) At initial aqueous Mg/Ca molar ratios ⩽ 1:6, Mg-calcite formation occurs via direct precipitation from solution. (ii) Conversely, at higher initial Mg/Ca molar ratios, Mg-calcite forms via an intermediate Mg-rich ACC phase. In the latter case, the final product is a calcite with up to 20 mol% Mg. This Mg content is significant higher than that of the Mg-rich ACC precursor phase. Thus, a strong net uptake of Mg ions from the solution into the crystalline precipitate throughout and also subsequent to ACC transformation is postulated. Moreover, the temporal evolution of the geochemical composition of the reactive solution and the Mg-ACC has no significant effect on the obtained ;solubility product; of Mg-ACC. The enrichment of Mg in calcite throughout and subsequent to Mg-ACC transformation is likely affected by the high aqueous Mg/Ca ratio and carbonate alkalinity concentrations in the reactive solution. The experimental results have a bearing on the formation mechanism of Mg-rich calcites in marine early diagenetic environments, where high carbonate alkalinity concentrations are the rule rather than the exception, and on the insufficiently investigated inorganic component of biomineralisation pathways in many calcite secreting organisms.

  1. İl sağlık müdürlüklerinde bulaşıcı hastalıklar insan gücünün değerlendirmesi

    Directory of Open Access Journals (Sweden)

    Raika Durusoy

    2011-09-01

    Full Text Available ÖzetAmaç: Türkiye’de il sağlık müdürlüklerinin bulaşıcı hastalıklar şubelerinde görev yapan personelin ve yöneticilerinin; meslek, deneyim, personel değişimi ve hizmet içi eğitimlerini değerlendirmek. Yöntem: Kesitsel tipteki bu araştırma kapsamında 2007 yılında Türkiye’de İl Sağlık Müdürlüklerinde bulaşıcı hastalıklar konusunda çalışan sağlık personeline (müdür yardımcıları ve bulaşıcı hastalıklar şube personeli bir anket uygulanmıştır. Anket resmi yazı ile şubelere ulaştırılmış, şubeler tarafından doldurulan anketler değerlendirilmiştir. Seksen bir ilin 78’inden yanıt alınmıştır (yanıt oranı %96.3. Ankette bulaşıcı hastalıklar konusunda çalışan personelin sosyodemografik özellikleri, meslekleri, görev süreleri, öğrenim durumları ve aldıkları hizmet içi eğitimler sorulmuştur. Ayrıca Bulaşıcı Hastalıklar Şubesinden son iki yılda ayrılanların sayısı ve özellikleri de sorgulanmıştır. Bulgular: Sağlık Bakanlığı’nın il düzeyinde bulaşıcı hastalık kontrolünde çalışan insan gücü, yanıt alınan 78 Sağlık Müdürlüğü için 77 il sağlık müdür yardımcısı, 71 şube müdürü ve 518 şube personelinden oluşmaktadır. Müdür yardımcılarının %97.4’ü, şube müdürlerinin %80.3’ü hekimdir. Müdür yardımcılarının Bulaşıcı Hastalıklar Şube Müdürlüğünde çalışma deneyimine bakıldığında %73.3’ünün daha önce şube müdürlüğü yapmadığı saptanmıştır, %97.3’ünün şube müdürlüğü dışındaki pozisyonlardan herhangi biri için şubede çalışmadığı saptanmıştır. Şube müdürlerinin %22.5’inin şubede çalışma deneyimi vardır. Kırk bir (%57.7 şube müdürü ve 22 (%28.6 müdür yardımcısı, bulaşıcı hastalıklar konusunda eğitici eğitimi almıştır. Bulaşıcı Hastalık Şube Müdürlüklerinde Şube Müdürü dışında çalışan personelin meslek

  2. Indampen van dunne mestfracties in combinatie met een luchtwasser

    NARCIS (Netherlands)

    Hoeksma, P.; Hol, A.; Verheijen, R.; Verdoes, N.

    2017-01-01

    The effect of an evaporator/air-scrubber combination on the reduction of ammonia and odour was evaluated and the evaporation capacity was assessed. It was concluded that at pig farms substantial reduction (one third) of the slurry volume can cost effectively be achieved while maintaining ammonia and

  3. Amblyomma tapirellum (Dunn, 1933) collected from tropical forest canopy

    NARCIS (Netherlands)

    Loaiza, J.R.; Miller, M.J.; Bermingham, E.; Sanjur, O.I.; Jansen, P.A.; Rovira, J.R.; Alvarez, E.; Rodriguez, E.; Davis, P.; Dutari, L.C.; Pecor, J.; Foley, D.; Radtke, M.; Pongsiri, M.J.

    2013-01-01

    Free-ranging ticks are widely known to be restricted to the ground level of vegetation. Here, we document the capture of the tick species Amblyomma tapirellum in light traps placed in the forest canopy of Barro Colorado Island, central Panama. A total of forty eight adults and three nymphs were

  4. Re-examining the 26Mg(α ,α')26Mg reaction: Probing astrophysically important states in 26Mg

    Science.gov (United States)

    Adsley, P.; Brümmer, J. W.; Li, K. C. W.; Marín-Lámbarri, D. J.; Kheswa, N. Y.; Donaldson, L. M.; Neveling, R.; Papka, P.; Pellegri, L.; Pesudo, V.; Pool, L. C.; Smit, F. D.; van Zyl, J. J.

    2017-11-01

    Background: The 22Ne(α ,n )25Mg reaction is one of the neutron sources for the s process in massive stars. The properties of levels in 26Mg above the α -particle threshold control the strengths of the 22Ne(α ,n )25Mg and 22Ne(α ,γ )26Mg reactions. The strengths of these reactions as functions of temperature are one of the major uncertainties in the s process. Purpose: Information on the existence, spin, and parity of levels in 26Mg can assist in constraining the strengths of the 22Ne(α ,γ )26Mg and 22Ne(α ,n )25Mg reactions, and therefore in constraining s -process abundances. Methods: Inelastically scattered α particles from a 26Mg target were momentum-analyzed in the K600 magnetic spectrometer at iThemba LABS, South Africa. The differential cross sections of states were deduced from the focal-plane trajectory of the scattered α particles. Based on the differential cross sections, spin and parity assignments to states are made. Results: A newly assigned 0+ state was observed in addition to a number of other states, some of which can be associated with states observed in other experiments. Some of the deduced Jπ values of the states observed in the present study show discrepancies with those assigned in a similar experiment performed at RCNP Osaka. The reassignments and additions of the various states can strongly affect the reaction rate at low temperatures. Conclusion: The number, location, and assignment of levels in 26Mg that may contribute to the 22Ne+α reactions are not clear. Future experimental investigations of 26Mg must have an extremely good energy resolution to separate the contributions from different levels. Coincidence experiments of 26Mg provide a possible route for future investigations.

  5. Antibacterial biodegradable Mg-Ag alloys

    Directory of Open Access Journals (Sweden)

    D Tie

    2013-06-01

    Full Text Available The use of magnesium alloys as degradable metals for biomedical applications is a topic of ongoing research and the demand for multifunctional materials is increasing. Hence, binary Mg-Ag alloys were designed as implant materials to combine the favourable properties of magnesium with the well-known antibacterial property of silver. In this study, three Mg-Ag alloys, Mg2Ag, Mg4Ag and Mg6Ag that contain 1.87 %, 3.82 % and 6.00 % silver by weight, respectively, were cast and processed with solution (T4 and aging (T6 heat treatment.The metallurgical analysis and phase identification showed that all alloys contained Mg4Ag as the dominant β phase. After heat treatment, the mechanical properties of all Mg-Ag alloys were significantly improved and the corrosion rate was also significantly reduced, due to presence of silver. Mg(OH2 and MgO present the main magnesium corrosion products, while AgCl was found as the corresponding primary silver corrosion product. Immersion tests, under cell culture conditions, demonstrated that the silver content did not significantly shift the pH and magnesium ion release. In vitro tests, with both primary osteoblasts and cell lines (MG63, RAW 264.7, revealed that Mg-Ag alloys show negligible cytotoxicity and sound cytocompatibility. Antibacterial assays, performed in a dynamic bioreactor system, proved that the alloys reduce the viability of two common pathogenic bacteria, Staphylococcus aureus (DSMZ 20231 and Staphylococcus epidermidis (DSMZ 3269, and the results showed that the killing rate of the alloys against tested bacteria exceeded 90%. In summary, biodegradable Mg-Ag alloys are cytocompatible materials with adjustable mechanical and corrosion properties and show promising antibacterial activity, which indicates their potential as antibacterial biodegradable implant materials.

  6. Intra-individual comparison of different contrast media concentrations (300 mg, 370 mg and 400 mg iodine) in MDCT

    Energy Technology Data Exchange (ETDEWEB)

    Behrendt, Florian F.; Keil, Sebastian; Plumhans, Cedric; Guenther, Rolf W. [RWTH Aachen University, Department of Diagnostic Radiology, University Hospital, Aachen (Germany); Pietsch, Hubertus; Jost, Gregor; Sieber, Martin A.; Seidensticker, Peter [Bayer Schering Pharma AG, Berlin (Germany); Mahnken, Andreas H. [RWTH Aachen University, Department of Diagnostic Radiology, University Hospital, Aachen (Germany); RWTH Aachen University, Applied Medical Engineering, Helmholtz-Institute for Biomedical Engineering, Aachen (Germany)

    2010-07-15

    To compare intra-individual contrast enhancement in multi-detector-row computed tomography (MDCT) using contrast media (CM) containing 300, 370 and 400 mg iodine per ml (mgI/ml). Six pigs underwent repeated chest MDCT using three different CM (iopromide 300, iopromide 370, iomeprol 400). An identical iodine delivery (IDR) rate of 1.5 gI/s and a constant total iodine dose of 300 mg/kg body weight were used. Dynamic CT were acquired at the level of the pulmonary artery, and the ascending and descending aorta. After the time enhancement curves were computed, the pulmonary and aortic peak enhancement, time to peak and plateau time above 300 HU were calculated. Intra-individual peak contrast enhancement was significantly higher for the 300 mgI/ml contrast medium compared with the 370 and 400 mgI/ml media: pulmonary trunk 595 HU vs 516 HU (p = 0.0093) vs 472HU (p = 0.0005), and aorta 505 HU vs 454 HU (p = 0.0008) vs 439 HU (p = 0.0001), respectively. Comparison of time to peaks showed no significant difference. Plateau times were significantly longer for the 300 mgI/ml than for the 370 and 400 mgI/ml CM at all anatomical sites. Given normalised IDR and total iodine burden, the use of CM with a standard concentration with 300 mg iodine/ml provides improved contrast enhancement compared with highly concentrated CM in the chest. (orig.)

  7. The effect of the MgO buffer layer thickness on magnetic anisotropy in MgO/Fe/Cr/MgO buffer/MgO(001)

    Energy Technology Data Exchange (ETDEWEB)

    Kozioł-Rachwał, Anna, E-mail: a.koziolrachwal@aist.go.jp [National Institute of Advanced Industrial Science and Technology, Spintronics Research Center, Tsukuba, Ibaraki 305-8568 (Japan); AGH University of Science and Technology, Faculty of Physics and Applied Computer Science, al. Mickiewicza 30, 30-059 Kraków (Poland); Nozaki, Takayuki; Zayets, Vadym; Kubota, Hitoshi; Fukushima, Akio; Yuasa, Shinji [National Institute of Advanced Industrial Science and Technology, Spintronics Research Center, Tsukuba, Ibaraki 305-8568 (Japan); Suzuki, Yoshishige [National Institute of Advanced Industrial Science and Technology, Spintronics Research Center, Tsukuba, Ibaraki 305-8568 (Japan); Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama, Toyonaka, Osaka 560-8531 (Japan)

    2016-08-28

    The relationship between the magnetic properties and MgO buffer layer thickness d was studied in epitaxial MgO/Fe(t)/Cr/MgO(d) layers grown on MgO(001) substrate in which the Fe thickness t ranged from 0.4 nm to 1.1 nm. For 0.4 nm ≤ t ≤ 0.7 nm, a non-monotonic coercivity dependence on the MgO buffer thickness was shown by perpendicular magneto-optic Kerr effect magnetometry. For thicker Fe films, an increase in the buffer layer thickness resulted in a spin reorientation transition from perpendicular to the in-plane magnetization direction. Possible origins of these unusual behaviors were discussed in terms of the suppression of carbon contamination at the Fe surface and changes in the magnetoelastic anisotropy in the system. These results illustrate a method to control magnetic anisotropy in MgO/Fe/Cr/MgO(d) via an appropriate choice of MgO buffer layer thickness d.

  8. Ultraviolet spectra of Mg in liquid helium

    International Nuclear Information System (INIS)

    Moriwaki, Y.; Morita, N.

    1999-01-01

    Emission and absorption spectra of Mg atoms implanted in liquid helium have been observed in the ultraviolet region. We have presented a model of exciplex formation of Mg-He 10 and found that this model is more suitable for understanding the dynamics in the 3s3p 1 P→3s 21 S transition than the bubble model. (orig.)

  9. Akkeçi oğlaklarında doğum ve sütten kesim ağırlığına etki eden bazı çevre faktörleri üzerine araştırmalar

    OpenAIRE

    KAHRAMAN, Züleyha

    1991-01-01

     Bu araştırmada, Akkeçi oğlaklarında doğum ve sütten kesim ağırlıkları üzerine ana yaşı, cinsiyet, doğum şekli, ananın vücut ağırlığı ve bunlara ek ola rak oğlakların doğumdaki ağırlıklarının sütten kesim ağırlığına etkileri incelenmiştir. Araştırmanın ma teryalini Ankara Üniversitesi Ziraat Fakültesi Zootekni Bölümü' nde yetiştirilen çeşitli yaştaki Akkeçiler ve bunlardan elde edilen oğlaklar oluşturmuştur. Yapılan önem kontrolleri sonucunda; oğlakların doğum ağ...

  10. Optical absorption and thermoluminescence in Mg O, Mg O:Ni and Mg O:Li irradiated at room temperature

    International Nuclear Information System (INIS)

    Delgado, L.

    1984-01-01

    Optical absorption and thermoluminescence (TL) studies in Mg O, Mg O:Ni and Mg O:Li irradiated at room temperature are presented. In pure Mg O the thermal annihilation of Fe3+ by recombination with thermally released electrons at ∼ 90 and 175 degree centigree and the V center annealing by hole release up to 100 degree centigree cause the observed glow peaks at these temperatures. The TL excitation spectrum shows two maxima at 245 nm (electron center) and 288 nm (Fe3+). In Mg O:Ni X irradiation induces Fe 2 + →- Fe 3 + and Ni 2 + → Ni 3 + oxidations. Two TL emission bands centered at 110 degree centigree (red) and 80 o C (green) are assigned to electron release and their recombination at Fe 3 + and Ni 3 + respectively. In Mg O:Li two TL emission bands, one blue (430 nm) and the other red (730 nm) with excitation maxima at 245 nm (electron center) and 200 nm (hole center) respectively are observed. No V-center formation was detected in both Ni and Li doped samples. (Author) 42 refs

  11. Mg2BIV: Narrow Bandgap Thermoelectric Semiconductors

    Science.gov (United States)

    Kim, Il-Ho

    2018-05-01

    Thermoelectric materials can convert thermal energy directly into electric energy and vice versa. The electricity generation from waste heat via thermoelectric devices can be considered as a new energy source. For instance, automotive exhaust gas and all industrial processes generate an enormous amount of waste heat that can be converted to electricity by using thermoelectric devices. Magnesium compound Mg2BIV (BIV = Si, Ge or Sn) has a favorable combination of physical and chemical properties and can be a good base for the development of new efficient thermoelectrics. Because they possess similar properties to those of group BIV elemental semiconductors, they have been recognized as good candidates for thermoelectric applications. Mg2Si, Mg2Ge and Mg2Sn with an antifluorite structure are narrow bandgap semiconductors with indirect band gaps of 0.77 eV, 0.74 eV, and 0.35 eV, respectively. Mg2BIV has been recognized as a promising material for thermoelectric energy conversion at temperatures ranging from 500 K to 800 K. Compared to other thermoelectric materials operating in the similar temperature range, such as PbTe and filled skutterudites, the important aspects of Mg2BIV are non-toxic and earth-abundant elements. Based on classical thermoelectric theory, the material factor β ( m* / m e)3/2μκ L -1 can be utilized as the criterion for thermoelectric material selection, where m* is the density-of-states effective mass, me is the mass of an electron, μ is the carrier mobility, and κL is the lattice thermal conductivity. The β for magnesium silicides is 14, which is very high compared to 0.8 for iron silicides, 1.4 for manganese silicides, and 2.6 for silicon-germanium alloys. In this paper, basic phenomena of thermoelectricity and transport parameters for thermoelectric materials were briefly introduced, and thermoelectric properties of Mg2BIV synthesized by using a solid-state reaction were reviewed. In addition, various Mg2BIV compounds were discussed

  12. Superconductivity in MgB{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Muranaka, Takahiro; Akimitsu, Jun [Aoyama Gakuin Univ., Kanagawa (Japan). Dept. of Physics and Mathematics

    2011-07-01

    We review superconductivity in MgB{sub 2} in terms of crystal and electronic structure, electron-phonon coupling, two-gap superconductivity and application. Finally, we introduce the development of new superconducting materials in related compounds. (orig.)

  13. Additive Manufacturing of Magnesium (Mg) Alloys

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed work is to investigate additive manufacturing techniques for Mg alloys.  It will leverage off research being conducted at University of Florida and...

  14. Chondrogenic differentiation of ATDC5-cells under the influence of Mg and Mg alloy degradation.

    Science.gov (United States)

    Martinez Sanchez, Adela H; Feyerabend, Frank; Laipple, Daniel; Willumeit-Römer, Regine; Weinberg, Annelie; Luthringer, Bérengère J C

    2017-03-01

    Biodegradable magnesium (Mg)-based materials are a potential alternative to permanent implants for application in children. Nevertheless effects of those materials on growth plate cartilage and chondrogenesis have not been previously evaluated. In vitro differentiation of ATDC5 cells was evaluated under the influence of pure Mg (PMg), Mg with 10wt% of gadolinium (Mg-10Gd) and Mg with 2wt% of silver (Mg-2Ag) degradation products (extracts) and direct cell culture on the materials. Gene expression showed an inhibitory effect on ATDC5 mineralization with the three extracts and a chondrogenic potential of Mg-10Gd. Cells cultured in Mg-10Gd and Mg-2Ag extracts showed the same proliferation and morphology than cells cultured in growth conditions. Mg-10Gd induced an increase in production of ECM and a bigger cell size, similar to the effects found with differentiation conditions. An increased metabolic activity was observed in cells cultured under the influence of Mg-10Gd extracts, indicated by an acidic pH during most of the culture period. After 7days of culture on the materials, ATDC5 growth, distribution and ECM synthesis were higher on Mg-10Gd samples, followed by Mg-2Ag and PMg, which was influenced by the homogeneity and composition of the degradation layer. This study confirmed the tolerance of ATDC5 cells to Mg-based materials and a chondrogenic effect of Mg-10Gd. Further studies in vitro and in vivo are necessary to evaluate cell reactions to those materials, as well as the effects on bone growth and the biocompatibility of the alloying system in the body. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. Mg/Ca of Continental Ostracode Shells

    Science.gov (United States)

    Ito, E.; Forester, R. M.; Marco-Barba, J.; Mezquita, F.

    2007-12-01

    Marine ionic chemistry is thought to remain constant. This, together with the belief that marine calcifiers partition Mg/Ca in a systematic manner as functions of temperature (and Mg/Ca) of water forms the basis of the Mg/Ca thermometer. In continental settings both of these assumptions are usually not true. Continental waters contain a wide variety of solutes in absolute and relative ion concentrations. Hence, waters with identical Mg/Ca may have very different concentrations of Mg and Ca and very different anions. Here we use two examples to focus on the effects of ion chemistry on Mg/Ca partitioning in continental ostracode shells and we ignore the complexities of solute evolution, which can change Mg/Ca over timescales of minutes to millennia. Palacios-Fest and Dettman (2001) conducted a monthly study of ,Cypridopsis vidua at El Yeso Lake in Sonora, Mexico. They established a relation between temperature and average shell Mg/Ca using regression analyses on averaged data. When their Mg/Ca-temperature relation is applied to monthly ,C. vidua data from Page Pond near Cleveland, Ohio, water temperatures of -8 to -1°C are obtained. The observed Mg/Ca ranges for El Yeso Lake (0.31 to 0.46) and Page Pond (0.33 to 0.46) are similar, as are their specific conductivities (700 to 850μS for El Yeso Lake; 400 to 600μS for Page Pond). However, [Ca] is 140-260 mg/L for El Yeso, but only 70-90 mg/L for Page Pond. Page Pond data, in fact, shows a good temperature shell Mg/Ca relation for .C. vidua, but the relation is different from that at El Yeso. Hence, shell Mg/Ca is a multi-valued, family of curves function of temperature and Mg/Ca of water that depends on the [Mg] and [Ca] values in water and perhaps other factors. Our second example comes from sites near Valencia, Spain and involves shell data for ,Cyprideis torosa, an estuarine ostracode that is tolerant of a wide range of salinity and can live in continental waters as long as the carbonate alkalinity to Ca ratio is

  16. Prussian Blue Mg-Li Hybrid Batteries.

    Science.gov (United States)

    Sun, Xiaoqi; Duffort, Victor; Nazar, Linda F

    2016-08-01

    The major advantage of Mg batteries relies on their promise of employing an Mg metal negative electrode, which offers much higher energy density compared to graphitic carbon. However, the strong coulombic interaction of Mg 2+ ions with anions leads to their sluggish diffusion in the solid state, which along with a high desolvation energy, hinders the development of positive electrode materials. To circumvent this limitation, Mg metal negative electrodes can be used in hybrid systems by coupling an Li + insertion cathode through a dual salt electrolyte. Two "high voltage" Prussian blue analogues (average 2.3 V vs Mg/Mg 2+ ; 3.0 V vs Li/Li + ) are investigated as cathode materials and the influence of structural water is shown. Their electrochemical profiles, presenting two voltage plateaus, are explained based on the two unique Fe bonding environments. Structural water has a beneficial impact on the cell voltage. Capacities of 125 mAh g -1 are obtained at a current density of 10 mA g -1 (≈C/10), while stable performance up to 300 cycles is demonstrated at 200 mA g -1 (≈2C). The hybrid cell design is a step toward building a safe and high density energy storage system.

  17. Formation and Corrosion Resistance of Mg-Al Hydrotalcite Film on Mg-Gd-Zn Alloy

    Science.gov (United States)

    Ba, Z. X.; Dong, Q. S.; Kong, S. X.; Zhang, X. B.; Xue, Y. J.; Chen, Y. J.

    2017-06-01

    An environment-friendly technique for depositing a Mg-Al hydrotalcite (HT) (Mg6Al2(OH)16-CO3ṡ4H2O) conversion film was developed to protect the Mg-Gd-Zn alloy from corrosion. The morphology and chemical compositions of the film were analyzed by scanning electronic microscope (SEM) equipped with energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD) and Raman spectroscopy (RS), respectively. The electrochemical test and hydrogen evolution test were employed to evaluate the biocorrosion behavior of Mg-Gd-Zn alloy coated with the Mg-Al HT film in the simulated body fluid (SBF). It was found that the formation of Mg-Al HT film was a transition from amorphous precursor to a crystalline HT structure. The HT film can effectively improve the corrosion resistance of magnesium alloy. It indicates that the process provides a promising approach to modify Mg-Gd-Zn alloy.

  18. Microstructural evolution in Mg-rich Mg-Zn-Y alloys

    International Nuclear Information System (INIS)

    Biswas, T.; Ranganathan, S.; Nair, S.; Bajargan, G.

    2005-01-01

    Mg-rich Mg-Zn-Y alloys with nominal compositions Mg 97 Zn 1 Y 2 , Mg 97 Zn 2 Y 1 , Mg 92 Zn 6.5 Y 1.5 and Mg 97-x Zn 1 Y 2 Zr x have been chosen for the present study. These alloys are prepared by using sand casting mold. The sand cast alloys are remelted and subjected to copper mold casting and melt spinning techniques. The effect of cooling rate on microstructures was studied. It is observed that the size of the precipitates decreases with an increase of cooling rate. The formation of nano precipitates results in higher strength of the alloy as compared to the conventional alloys. The microstructures of melt spun ribbons are compared with RS/PM (rapidly solidified power metallurgy) Mg 97 Zn 1 Y 2 alloy, obtained from a different source. (author)

  19. Çokkültürlü Eğitim ve Öğretim Yeterliğine İlişkin Teorik Bir Çözümleme

    OpenAIRE

    KILIÇOĞLU, Gökhan

    2015-01-01

    Yirminci yüzyılın yılların başlarından bu yana göç hareketleriyle etnik çeşitliliği artan dünya günümüzde küreselleşmekte ve birçok farklılığı içerisinde barındırır hale gelmektedir. Dolayısıyla küreselleşen dünya, öğretmenlerin farklı kültürel geçmişe sahip olan öğrencilerin geçmişlerini ve deneyimlerini göz önünde bulundurarak çokkültürlü ve evrensel bakış açısına sahip olmalarını gerektirmektedir. Özellikle farklı kültürleri içerisinde barındıran toplumlar, farklılıklara sahip öğrenciler a...

  20. Melting relations in the MgO-MgSiO3 system up to 70 GPa

    Science.gov (United States)

    Ohnishi, Satoka; Kuwayama, Yasuhiro; Inoue, Toru

    2017-06-01

    Melting experiments in a binary system MgO-MgSiO3 were performed up to 70 GPa using a CO2 laser heated diamond anvil cell. The quenched samples were polished and analyzed by a dualbeam focused ion beam (FIB) and a field emission scanning electron microscope (FE-SEM), respectively. The liquidus phase and the eutectic composition were determined on the basis of textual and chemical analyses of sample cross sections. Our experimental results show that the eutectic composition is the Si/Mg molar ratio of 0.76 at 35 GPa and it decreases with increasing pressure. Above 45 GPa, it becomes relatively constant at about 0.64-0.65 Si/Mg molar ratio. Using our experimental data collected at a wide pressure range up to 70 GPa together with previous experimental data, we have constructed a thermodynamic model of the eutectic composition of the MgO-MgSiO3 system. The eutectic composition extrapolated to the pressure and temperature conditions at the base of the mantle is about 0.64 Si/Mg molar ratio. The modeled eutectic composition is quite consistent with a previous prediction from ab initio calculations (de Koker et al. in Earth Planet Sci Lett 361:58-63, 2013), suggesting that the simple assumption of a non-ideal regular solution model can well describe the melting relation of the MgO-MgSiO3 system at high pressure. Our results show that the liquidus phase changes from MgO-periclase to MgSiO3-bridgmanite at 35 GPa for the simplified pyrolite composition ( 0.7 Si/Mg molar ratio), while MgSiO3-bridgmanite is the liquidus phase at the entire lower mantle conditions for the chondritic composition ( 0.84 Si/Mg molar ratio).

  1. Chondrogenic differentiation of ATDC5-cells under the influence of Mg and Mg alloy degradation

    Energy Technology Data Exchange (ETDEWEB)

    Martinez Sanchez, Adela H., E-mail: adela.martinez@hzg.de [Helmholtz-Zentrum Geesthacht, Institute of Material Research, Department for Structural Research on Macromolecules, Geesthacht (Germany); Feyerabend, Frank; Laipple, Daniel; Willumeit-Römer, Regine [Helmholtz-Zentrum Geesthacht, Institute of Material Research, Department for Structural Research on Macromolecules, Geesthacht (Germany); Weinberg, Annelie [Department of Orthopedics and Orthopedic Surgery, Medical University of Graz (Austria); Luthringer, Bérengère J.C. [Helmholtz-Zentrum Geesthacht, Institute of Material Research, Department for Structural Research on Macromolecules, Geesthacht (Germany)

    2017-03-01

    Biodegradable magnesium (Mg)-based materials are a potential alternative to permanent implants for application in children. Nevertheless effects of those materials on growth plate cartilage and chondrogenesis have not been previously evaluated. In vitro differentiation of ATDC5 cells was evaluated under the influence of pure Mg (PMg), Mg with 10 wt% of gadolinium (Mg-10Gd) and Mg with 2 wt% of silver (Mg-2Ag) degradation products (extracts) and direct cell culture on the materials. Gene expression showed an inhibitory effect on ATDC5 mineralization with the three extracts and a chondrogenic potential of Mg-10Gd. Cells cultured in Mg-10Gd and Mg-2Ag extracts showed the same proliferation and morphology than cells cultured in growth conditions. Mg-10Gd induced an increase in production of ECM and a bigger cell size, similar to the effects found with differentiation conditions. An increased metabolic activity was observed in cells cultured under the influence of Mg-10Gd extracts, indicated by an acidic pH during most of the culture period. After 7 days of culture on the materials, ATDC5 growth, distribution and ECM synthesis were higher on Mg-10Gd samples, followed by Mg-2Ag and PMg, which was influenced by the homogeneity and composition of the degradation layer. This study confirmed the tolerance of ATDC5 cells to Mg-based materials and a chondrogenic effect of Mg-10Gd. Further studies in vitro and in vivo are necessary to evaluate cell reactions to those materials, as well as the effects on bone growth and the biocompatibility of the alloying system in the body. - Highlights: • Degradation of PMg, and Mg-2Ag do not influence ATDC5 cells growth and chondrogenic redifferentiation. • Mg-10Gd enhances fast chondrogenic redifferentiation and expression of hyperthrophic markers on ATDC5 cells. • Further evaluation of the effects of PMg, Mg-10Gd and Mg-2Ag in vivo are necessary to confirm its potential for application in growing bones.

  2. Chondrogenic differentiation of ATDC5-cells under the influence of Mg and Mg alloy degradation

    International Nuclear Information System (INIS)

    Martinez Sanchez, Adela H.; Feyerabend, Frank; Laipple, Daniel; Willumeit-Römer, Regine; Weinberg, Annelie; Luthringer, Bérengère J.C.

    2017-01-01

    Biodegradable magnesium (Mg)-based materials are a potential alternative to permanent implants for application in children. Nevertheless effects of those materials on growth plate cartilage and chondrogenesis have not been previously evaluated. In vitro differentiation of ATDC5 cells was evaluated under the influence of pure Mg (PMg), Mg with 10 wt% of gadolinium (Mg-10Gd) and Mg with 2 wt% of silver (Mg-2Ag) degradation products (extracts) and direct cell culture on the materials. Gene expression showed an inhibitory effect on ATDC5 mineralization with the three extracts and a chondrogenic potential of Mg-10Gd. Cells cultured in Mg-10Gd and Mg-2Ag extracts showed the same proliferation and morphology than cells cultured in growth conditions. Mg-10Gd induced an increase in production of ECM and a bigger cell size, similar to the effects found with differentiation conditions. An increased metabolic activity was observed in cells cultured under the influence of Mg-10Gd extracts, indicated by an acidic pH during most of the culture period. After 7 days of culture on the materials, ATDC5 growth, distribution and ECM synthesis were higher on Mg-10Gd samples, followed by Mg-2Ag and PMg, which was influenced by the homogeneity and composition of the degradation layer. This study confirmed the tolerance of ATDC5 cells to Mg-based materials and a chondrogenic effect of Mg-10Gd. Further studies in vitro and in vivo are necessary to evaluate cell reactions to those materials, as well as the effects on bone growth and the biocompatibility of the alloying system in the body. - Highlights: • Degradation of PMg, and Mg-2Ag do not influence ATDC5 cells growth and chondrogenic redifferentiation. • Mg-10Gd enhances fast chondrogenic redifferentiation and expression of hyperthrophic markers on ATDC5 cells. • Further evaluation of the effects of PMg, Mg-10Gd and Mg-2Ag in vivo are necessary to confirm its potential for application in growing bones.

  3. Effects of limestone, N, K and Mg fertilizers on Mg absorption by oats and barley

    Energy Technology Data Exchange (ETDEWEB)

    Alston, A M

    1966-01-01

    Oats grown in a pot experiment on two sandy loams were sampled at four stages of growth. Neither KCl nor MgSO/sub 4/. 7H/sub 2/O had any effect on yield but % Mg and total Mg uptake were consistently decreased by applying K and increased by applying Mg. Ca(NO/sub 3/)/sub 2/ increased % Mg more than did (NH/sub 4/)/sub 2/SO/sub 4/, but yield and total Mg uptake were higher where (NH/sub 4/)/sub 2/SO/sub 4/ was applied. The effects of fertilizers were similar on both soils. The effects of applying (NH/sub 4/)/sub 2/SO/sub 4/ and NaNO/sub 2/ to the soil on % Mg in barley were compared in a field experiment on an acid loam to which several rates of limestone had been applied. Treatments had no effect on the % Mg in grain or straw at maturity. At four earlier stages of growth (NH/sub 4/)/sub 2/SO)/sub 4/ increased % Mg in the plants more than did NaNO/sub 2/. Limestone slightly increased % Mg. Nitrification of NH/sub 4/ in the soil was rapid.

  4. Mg Incorporation Efficiency in Pulsed MOCVD of N-Polar GaN:Mg

    Science.gov (United States)

    Marini, Jonathan; Mahaboob, Isra; Hogan, Kasey; Novak, Steve; Bell, L. D.; Shahedipour-Sandvik, F.

    2017-10-01

    We report on the effect of growth polarity and pulsed or δ -doped growth mode on impurity incorporation in metalorganic chemical vapor deposition-grown GaN. In Ga-polar orientation, up to 12× enhancement in Mg concentration for given Mg flow rate is observed, resulting in enhanced p-type conductivity for these samples. In contrast, this enhancement effect is greatly diminished for N-polar samples, falling off with increasing Mg flow and showing maximum enhancement of 2.7× at 30 nmol/min Mg flow. At higher Mg flow rates, Mg incorporation at normal levels did not correspond to p-type conductivity, which may be due to Mg incorporation at nonacceptor sites. Concentrations of C, O, and Si were also investigated, revealing dependence on Mg flow in N-polar pulsed samples. Carbon incorporation was found to decrease with increasing Mg flow, and oxygen incorporation was found to remain high across varied Mg flow. These effects combine to result in N-polar samples that are not p-type when using the pulsed growth mode.

  5. Structural characteristics and corrosion behavior of biodegradable Mg-Zn, Mg-Zn-Gd alloys.

    Science.gov (United States)

    Kubásek, J; Vojtěch, D

    2013-07-01

    In this research, binary Mg-Zn (up to 3 wt% Zn) and ternary Mg-Zn-Gd (up to 3 wt% Gd, 3 wt% Zn) alloys were prepared by induction melting in an argon atmosphere. The structures of these alloys were characterized using light and scanning electron microscopy, energy dispersive spectrometry, X-ray diffraction and X-ray fluorescence. In addition, Brinell hardness measurements were taken to supplement these studies. Corrosion behavior was evaluated by immersion tests and potentiodynamic measurements in a physiological solution (9 g/l NaCl). Depending on the composition, structures of the as-cast alloys contained α-Mg dendrites, MgZn, Mg5Gd and Mg3Gd2Zn3 phases. Compared to pure Mg, zinc improved the corrosion resistance of binary Mg-Zn. Gadolinium also improved the corrosion resistance in the case of Mg-1Zn-3Gd alloy. The highest corrosion rate was observed for Mg-3Zn-3Gd alloy. Our results improve the understanding of the relationships between the structure and corrosion behavior of our studied alloy systems.

  6. Thermoelectric power of PrMg3

    Science.gov (United States)

    Isikawa, Yosikazu; Somiya, Kazuya; Koyanagi, Huruto; Mizushima, Toshio; Kuwai, Tomohiko; Tayama, Takashi

    2010-01-01

    PrMg3 is supposed to be one of the strongly correlated electron systems originated from the hybridization between the Pr 4f and conduction electrons, because the gigantic electronic specific heat coefficient C/T was observed at low temperatures. However, a typical behaviour of - ln T dependence was not observed in the temperature dependence of the electrical resistivity. The thermoelectric power S is a powerful tool to investigate the density of states at the Fermi energy. We measured carefully the thermoelectric power of PrMg3 in the temperature range between 2 and 300 K. S is extremely small, ranged within ±1 μV/K over the whole temperature. The value of S/T at low temperature limit was also significantly smaller than expected from the specific heat results. We therefore conclude that the density of state at the Fermi level is not enhanced in PrMg3.

  7. Thermoelectric power of PrMg3

    International Nuclear Information System (INIS)

    Isikawa, Yosikazu; Somiya, Kazuya; Koyanagi, Huruto; Mizushima, Toshio; Kuwai, Tomohiko; Tayama, Takashi

    2010-01-01

    PrMg 3 is supposed to be one of the strongly correlated electron systems originated from the hybridization between the Pr 4f and conduction electrons, because the gigantic electronic specific heat coefficient C/T was observed at low temperatures. However, a typical behaviour of - ln T dependence was not observed in the temperature dependence of the electrical resistivity. The thermoelectric power S is a powerful tool to investigate the density of states at the Fermi energy. We measured carefully the thermoelectric power of PrMg 3 in the temperature range between 2 and 300 K. S is extremely small, ranged within ±1 μV/K over the whole temperature. The value of S/T at low temperature limit was also significantly smaller than expected from the specific heat results. We therefore conclude that the density of state at the Fermi level is not enhanced in PrMg 3 .

  8. Excited states in 22Mg via the 12C(12C,2n)22Mg reaction

    International Nuclear Information System (INIS)

    Jewett, Cybele; Baktash, Cyrus; Bardayan, Daniel W.; Blackmon, Jeff C.; Chipps, K.; Galindo-Uribarri, Alfredo; Greife, U.; Gross, Carl J.; Jones, K. L.; Liang, Junjien; Livesay, Jake; Kozub, R. L.; Nesaraja, Caroline D; Radford, David C.; Sarazin, F.; Smith, Michael Scott; Thomas, J. S.; Yu, Chang-Hong

    2007-01-01

    The 12C(12C, 2n)22Mg reaction was measured with the CLARION array and the RMS separator at the Holifield Facility of Oak Ridge National Laboratory. This experiment was performed to gather more information on the excited states in 22Mg, which might be of relevance to recent radioactive ion beam measurements of the astrophysically important 21Na(p,γ)22Mg reaction. The results are compared to direct measurements, transfer experiments and a competing experiment performed with Gammasphere

  9. Mifepristone 5 mg versus 10 mg for emergency contraception: double-blind randomized clinical trial

    Directory of Open Access Journals (Sweden)

    Carbonell JL

    2015-01-01

    Full Text Available Josep Lluis Carbonell,1 Ramon Garcia,2 Adriana Gonzalez,2 Andres Breto,2 Carlos Sanchez2 1Mediterranea Medica Clinic, Valencia, Spain; 2Eusebio Hernandez Gynecology and Obstetrics Teaching Hospital, Havana, Cuba Purpose: To estimate the efficacy and safety of 5 mg and 10 mg mifepristone for emergency contraception up to 144 hours after unprotected coitus. Methods: This double-blind randomized clinical trial was carried out at Eusebio Hernandez Hospital (Havana, Cuba. A total of 2,418 women who requested emergency contraception after unprotected coitus received either 5 mg or 10 mg mifepristone. The variables for assessing efficacy were the pregnancies that occurred and the fraction of pregnancies that were prevented. Other variables assessed were the side effects of mifepristone, vaginal bleeding, and changes in the date of the following menstruation. Results: There were 15/1,206 (1.2% and 9/1,212 (0.7% pregnancies in the 5 mg and 10 mg group, respectively (P=0.107. There were 88% and 93% prevented pregnancies in the 5 mg and 10 mg group, respectively. The side effect profiles were similar in both groups. Delayed menstruation ≥7 days was experienced by 4.9% and 11.0% of subjects in the 5 mg and 10 mg group, respectively (P=0.001. There was a significant high failure rate for women weighing >75 kg in the 5 mg group. Conclusion: It would be advisable to use the 10 mg dose of mifepristone for emergency contraception as there was a trend suggesting that the failure rate of the larger dose was lower. Keywords: mifepristone, emergency contraception

  10. Superconducting properties of MgB2 particle impregnated with Mg-based alloys

    International Nuclear Information System (INIS)

    Shimizu, Yusuke; Matsuda, Kenji; Mizutani, Manabu; Nishimura, Katsuhiko; Kawabata, Tokimasa; Ikeno, Susumu; Hishinuma, Yoshimitsu; Aoyama, Shigeki

    2011-01-01

    The three-dimensional penetration method combined with semi-solid casting (SS-3DPC) was utilized to prepare magnesium diboride (MgB 2 ) powder composite materials with various host materials of Mg, Mg-3%Al, Mg-3%Al-1%Zn, Mg-9%Al, and Mg-9%Al-1%Zn. X-ray diffraction measurements indicated predominant peak patterns of MgB 2 and a host alloy, implying that the host material tightly bonded MgB 2 grains without melting the MgB 2 powder. This was confirmed by SEM images. Measured electrical resistivity and magnetization versus temperature showed clear signals of superconducting transition temperature of 27-38 K for all the samples cut out from the billets. Magnetic hysteresis loop observed at 5 K enabled us to estimate a critical current density (J c ) based on the extended Bean model. Additions of aluminum and zinc elements to magnesium host-matrix were found to enhance J c and increase residual resistivity (ρ 0 ) suggesting that aluminum and zinc have an effect on pinning magnetic flux flow for J c enhancement, and scattering conduction electrons for increase of ρ 0 . (author)

  11. Piezoelectric RL shunt damping of flexible structures

    DEFF Research Database (Denmark)

    Høgsberg, Jan Becker; Krenk, Steen

    2015-01-01

    in the present analysis is based on equal damping of the two modes associated with the resonant vibration form of the structure. An important result of the presented calibration procedure is the explicit inclusion of a quasi-static contribution from the non-resonant vibration modes of the structure via a single...

  12. Tree exploration for Bayesian RL exploration

    NARCIS (Netherlands)

    Dimitrakakis, C.; Mohammadian, M.

    2008-01-01

    Research in reinforcement learning has produced algo-rithms for optimal decision making under uncertainty thatfall within two main types. The first employs a Bayesianframework, where optimality improves with increased com-putational time. This is because the resulting planning tasktakes the form of

  13. Electronic structure of MgB2

    Indian Academy of Sciences (India)

    Abstract. Results of ab initio electronic structure calculations on the compound MgB2 using the. FPLAPW method employing GGA for the exchange-correlation energy are presented. Total energy minimization enables us to estimate the equilibrium volume, c/a ratio and the bulk modulus, all of which are in excellent ...

  14. Electronic structure of MgB 2

    Indian Academy of Sciences (India)

    Results of ab initio electronic structure calculations on the compound MgB2 using the FPLAPW method employing GGA for the exchange-correlation energy are presented. Total energy minimization enables us to estimate the equilibrium volume, / ratio and the bulk modulus, all of which are in excellent agreement with ...

  15. doped LiMgPO4 phosphor

    Indian Academy of Sciences (India)

    attention because of their remarkable luminescence proper- ties and .... Figure 1. (a) X-ray diffraction patterns of LiMgPO4:Tb3+ phosphor and (b) standard data. ICDD file. .... ground signal which affects the signal to noise ratio [17]. MDD was ...

  16. Zihin Özürlü Öğrencilere Okuma Yazma Öğretme Konusunda Alt Özel Sınıf Öğretmenlerinin Görüş ve Önerileri

    Directory of Open Access Journals (Sweden)

    Mine Başal

    2002-07-01

    Full Text Available Niteliksel olarak planlanan bu araştırmanın amacı, zihin özürlü öğrencilere okuma yazma öğretme konusunda alt özel sınıf öğretmenlerinin görüş ve Önerilerini incelemektir. Araştırmanın verileri yarı-yapılandırılmış görüşmeler aracılığı ile toplanmıştır. Eskişehir ilinde bulunan yedi ali Özel sınıfın özel eğitim bölümü mezunu olmayan öğretmeni araştırmanın katılımcılarını oluşturmuştur. Görüşmeler 25-70 dakika arasında sürmüştür. Tümevarım yoluyla analiz edilen verilerden 29 temaya ulaşılmıştır. Daha sonra birleştirilerek 10 tema haline getirilen araştırmanın bulguları, öğretmenlerin okuma yazma öğretimine yönelik amaçlarım belirlemede farklı yollar izlediklerini, okuma yazma öğretiminde genellikle cümle yöntemini kullandıklarını ancak gerektiğinde farklı yöntemlerden de yararlandıklarını, aileden destek olmaksızın öğretimin zor olduğunu, araç-gereç sıkıntısı, kaynak eksikliği gibi sorunların yaşandığını ortaya kovmaktadır. Araştırma bulgularının zihin özürlü Öğrencilere okuma yazma öğreten öğretmenlere, özel eğitim bölümlerinde okuma yazma öğretimi lisans dersini okutan öğretim elemanlarına yol göstereceği düşünülmekledir. The purpose of the present study was to examine the opinions and suggestions of the teachers of special education classes towards leaching reading and writing to students with mental retardation. The data of the qualitative study were collected via semi-structured interviews. The participants of the study were seven teachers of special education classes in Eskişehir who did not have special education degrees. Interviews lasted about 25- 70 minutes. 29 themes were derived from the data. The related themes have been consolidated and ten themes remained. The results of the study revealed that teachers prefered to use different ways in order to determine their aims about teaching

  17. Tevfik Fikret’in Özgürlük Yolundaki “İzler”i “İzler” of Tevfik Fikret in the Wake of Freedom

    Directory of Open Access Journals (Sweden)

    Mutlu DEVECİ

    2012-09-01

    çıkar. İzleksel açıdan toplumsal olanı dışladığı şiirlerinde kendini onlardan ayrı hisseden şair, yalnızlık ve tekbaşınalığın getirdiği özgürlük sayesinde yaşama tutunur. “İzler” şiiri de bu izlek etrafında kurgulanmış bir varoluş şiiridir. Öznenin özgürlük yolunda, yalnız ve tekbaşına olduğunu dile getirdiği bu şiirde, kendi kendisiyle yüzleşen insanın ruh durumu anlatılır. Ontolojik bir sorun olan yalnızlık, yabancılaşma bağlamında bireysel ve toplumsal kaynaklı iletişimsizlik yaratır. Dönemin siyasi, sosyal ve ekonomik şartlarının şekillendirdiği şair, karakter ve yetişme tarzının da etkisi ile kendisini iletişimsizlikler içerisinde yalnız ve tekbaşına olarak hisseder. “İzler”de, olumsuz bir yalnızlığın koyu karanlığında yitip gitmeyerek kendine dönen şair, dünyadaki varlığı ile yüzleşir ve tekbaşınalığını bir güç olarak algılar. Şiirde, Varoluşçu felsefecilerin özgürlük anlayışına benzer bir anlayışla kendine, dünyaya ve çevresine bakan Tevfik Fikret, dış dünyayla ilişkiye girememenin bunaltısını yaşarken anlam arayışına yönelik eylemleri ile diğerlerinden farklı olduğunu hisseder. Servet-i Fünun kuşağının dünya ile en çok çatışma yaşayan şairi olan Tevfik Fikret, bu şiiri ile varoluşsal problemlerinden kurtulmak için içsel bir yolculuğa çıkarak kendisiyle yüzleşen ve bırakılmışlık bunaltısının sağaltım sürecini başlatan öznenin ruh halini yansıtır.

  18. Preliminary study of the characteristics of a high Mg containing Al-Mg-Si alloy

    International Nuclear Information System (INIS)

    Yan, F; McKay, B J; Fan, Z; Chen, M F

    2012-01-01

    An Al-20Mg-4Si high Mg containing alloy has been produced and its characteristics investigated. The as-cast alloy revealed primary Mg 2 Si particles evenly distributed throughout an α-Al matrix with a β-Al 3 Mg 2 fully divorced eutectic phase observed in interdendritic regions. The Mg 2 Si particles displayed octahedral, truncated octahedral, and hopper morphologies. Additions of Sb, Ti and Zr had a refining influence reducing the size of the Mg 2 Si from 52 ± 4 μm to 25 ± 0.1 μm, 35 ± 1 μm and 34 ± 1 μm respectively. HPDC tensile test samples could be produced with a 0.6 wt.% Mn addition which prevented die soldering. Solution heating for 1 hr was found to dissolve the majority of the Al 3 Mg 2 eutectic phase with no evidence of any effect on the primary Mg 2 Si. Preliminary results indicate that the heat treatment has a beneficial effect on the elongation and the UTS.

  19. Investigation of the 24Mg(d, p)25Mg reaction

    NARCIS (Netherlands)

    Meurders, F.; Korte, G. de

    1975-01-01

    Abstract Proton angular distributions from the 24Mg(d, p)25Mg reaction at Ed = 12.0 MeV have been measured with a split-pole magnetic spectrograph for Ex < 6 MeV at an average resolution (FWHM) of 7 keV. New ln values have been determined for three levels. A DWBA analysis yielded spectroscopic

  20. Investigation of the 26Mg(d, p)27Mg reaction

    NARCIS (Netherlands)

    Meurders, F.; Steld, A. van der

    1974-01-01

    The angular distributions of 31 protons groups from the 26Mg(d, p)27Mg reaction have been measured at Ed = 12.0 MeV with a split-pole magnetic spectrograph. Excitation energies have been determined for 29 bound states. Three new levels have been found. A DWBA analysis yields ln values for 19 levels;

  1. Respiratory outcomes following 100 mg/kg v. 200 mg/kg of poractant ...

    African Journals Online (AJOL)

    In keeping with current evidence, the initial dose of poractant alpha was increased from 100 mg/kg to 200 mg/kg. e outcomes of newborns requiring treatment with surfactant before and aer this change were reviewed. Methods. Electronic clinical records were reviewed of infants admitted to ACH who received surfactant ...

  2. Mg/Ca ratio in fertilization and agricultural soils, Mg percent of liming ...

    African Journals Online (AJOL)

    Strong increase of NPK (nitrogen, phosphorus and potassium) in mineral fertilization (fm) included relative delay in Mg supplementation and dilution in plant available silicon (Si) via recycled nutrients (rcl). (Silicon is not included in essential fertilizers in Finland.) Methods: We have assessed old data on Ca and Mg in ...

  3. Decay of a Jπ=36+ Resonance in the 24Mg+24Mg Reaction

    International Nuclear Information System (INIS)

    Salsac, M.-D.; Haas, F.; Courtin, S.

    2005-01-01

    For the 24 Mg+ 24 Mg reaction, striking narrow and correlated resonance structures have been observed previously in the excitation functions of the elastic and low-lying channels. In our study we have decided to focus on the resonance at E C M =45.7 MeV, which is known to have J π =36 + . Despite the very high excitation energy(∼60 MeV) in the 48 Cr composite system, this resonance has a narrow total width of 170 keV. To determine precisely which states in the inelastic 24 Mg channels carry away the resonance flux, an experiment, on the 24 Mg + 24 Mg reaction at energies On and OFF resonance, has been performed at the Legnaro Tandem accelerator using the Prisma fragment spectrometer associated with the CLARA γ array

  4. Mg II Line Variation of 32 Cygni

    Directory of Open Access Journals (Sweden)

    Young Woon Kang

    1992-12-01

    Full Text Available The Mg II lines have been extracted from the IUE archival spectra of 32 Cygni to investigate the effect of the atmospheric eclipse. The UV light curve has been reduced from the continuum flux at the center wavelength of 2807.5 Å in the IUE spectra. The equivalent width of the Mg II k absoption line has been measured for each spectra. The results of the light variation and flux tracing of the absorption line at the vicinity of the primary eclipse confirmed the atmospheric eclipse. The atmospheric effect lasted until the phase 0.06 in the absorptin line tracing, while it lasted until the phase 0.02 in the UV light curve, respectively.

  5. High temperature mechanical forming of Mg alloys

    International Nuclear Information System (INIS)

    Mwembela, A.; McQueen, H.J.; Myshlyaev, M.

    2002-01-01

    Mg alloys are hot worked in the range 180-450 o C and 0.0-10 s -1 ; the present project data are compared with a wide selection of published results. The flow stresses and their dependence on temperature and strain rate are fairly similar to simple Al alloys: however, the hot ductility is much lower (≤3 in torsion). Twinning plays a significant role in Mg alloys almost independently of temperature; the twins initiate at low strains in grains poorly oriented for basal slip and in consequence become well disposed for such slip. As T rises, there is increasing formation of subgrains that spread toward the grain centers from grain and twin boundaries: this is indicative of stress concentrations inducing non-basal sup which helps provide the geometrically necessary dislocations. Above about 240 o C, dynamic (DRX) nucleates at grain and twin boundaries, preferentially at intersections; this again is evidence of non-basal slip that provides the highly misoriented cells. The boundaries in which further strain concentrates producing further DRX. The microstructure remains very heterogeneous compared to the uniform dynamically recovered substructure in Al alloys, thus giving rise to the reduced ductility. These results are employed to interpret the mechanical and microstructural behavior of Mg alloys in extrusion, rolling and forging. (author)

  6. Mg,Ca-ATPase activity under irradiation

    International Nuclear Information System (INIS)

    Ladutin, V.V.; Orlova, V.V.; Lob, P.A.; Gerasiminko, I.V.; Mack, E.I.

    2003-01-01

    Full text: The influence of different doses irradiation at the Mg,Ca-ATPase activity at the rat brain has been investigated. The analyses were made at the apparatus of LKB and Carl-Ceis-Jena firm with help of reagents of Sigma and Boehringer firm. Rats decapitated after 1, 3, 6, 24 and 48 h after action of irradiation. Dose 0.206 C/kg. Erythrocytes. 1 and 3h after irradiation influence- decrease of Mg,Ca-ATPase activity to 86-87% relatively control level, 24 and 48 h - increase of activity to the control level. Dose 0.312 C/kg. Large hemispheres. 1h - decrease of ATPase activity to 90% relatively control, 3h - increase to control level, 24h - fall to 86%, after 48h small increase to 93% relatively control. Dose 9.287 C/kg. Large hemispheres. 1h - sharp fall of Mg, Ca-ATPase activity to 67 % relatively control, increase of activity to 96% after 3h and sharp fall of activity to 64% 6h after action of irradiation. Dose 9.287 C/kg. Cerebellum. 1h - sharp decrease of ATPase activity to 80%. After 3h -sharp increase to 160% relatively control level and sharp fall of ATPase activity to 47% relatively control after 6h. The mechanism of radiation pathology of active ion transport has been discussed

  7. Interstitial Fe in MgO

    CERN Document Server

    Mølholt, T E; Gunnlaugsson, H P; Svane, A; Masenda, H; Naidoo, D; Bharuth-Ram, K; Fanciulli, M; Gislason, H P; Johnston, K; Langouche, G; Ólafsson, S; Sielemann, R; Weyer, G

    2014-01-01

    Isolated Fe-57 atoms were studied in MgO single-crystals by emission Mossbauer spectroscopy following implantation of Mn-57 decaying to Fe-57. Four Mossbauer spectral components were found corresponding to different Fe lattice positions and/or charge states. Two components represent Fe atoms substituting Mg as Fe2+ and Fe3+, respectively; a third component is due to Fe in a strongly implantation-induced disturbed region. The fourth component, which is the focus of this paper, can be assigned to Fe at an interstitial site. Comparison of its measured isomer shift with ab initio calculations suggests that the interstitial Fe is located on, or close to, the face of the rock-salt MgO structure. To harmonize such an assignment with the measured near-zero quadrupole interaction a local motion process (cage motion) of the Fe has to be stipulated. The relation of such a local motion as a starting point for long range diffusion is discussed.

  8. Electronic structure of ferromagnet-insulator interfaces: Fe/MgO and Co/MgO

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, M.

    2007-07-11

    In this thesis the electronic structure of Fe/MgO{sub x} and Co/MgO{sub x} ferromagnet-insulator interfaces, representing material systems which are widely used in magnetic tunnel junctions, is studied by means of spin- and angle-resolved photoemission spectroscopy. The photoemission studies focus particularly on the response of the ferromagnetic electronic system in contact with MgO of varying stoichiometries, as this reflects the mechanisms of metal-oxide bonding at real ferromagnet-insulator interfaces. The correlation between chemical bonding and electronic structure formation is analyzed by combining information from core- and valence-band photoemission spectroscopy. The spectral features are compared to band structure calculations, which are performed using the SPR-KKR method. The Fe/MgO and Co/MgO systems are prepared by molecular beam epitaxy under ultrahigh vacuum conditions on well-defined (4 x 6) GaAs(001) substrates. A structural analysis by means of low-energy electron diffraction (LEED) reveals their body-centered cubic crystalline structure, whereas the chemical characterization by Auger electron spectroscopy is used to quantify the chemical environment at the sample surfaces. The magnetic analysis, using the magneto-optical Kerr effect, reveals the uniaxial anisotropy of the ferromagnetic layers. A crucial parameter is given by the MgO degree of oxidation, which is addressed by means of core-level spectroscopy and quantified by suitable fitting procedures of the Mg 2p core level. The results of the photoemission experiments show, that the electronic structure of the Fe/MgO and Co/MgO ferromagnet/insulator interfaces and, consequently, the interfacial spin polarization are sensitively controlled by the interface chemistry. In particular, three distinct scenarios are identified: the nearly stoichiometric, the oxygen-deficient and the over-oxidized ferromagnet/MgO interface. Each case is defined by innate characteristics of the electronic structure at

  9. Comparison of hydrogen storage properties of pure Mg and milled ...

    Indian Academy of Sciences (India)

    Administrator

    increase the hydriding and dehydriding rates, pure Mg was ground under hydrogen atmosphere (reactive .... Hydrogen storage properties of pure Mg and milled pure Mg. 833. Figure 3. ... elongated and flat shapes via collisions with the steel.

  10. Discharge behaviour of Mg-Al-Pb and Mg-Al-Pb-In alloys as anodes for Mg-air battery

    International Nuclear Information System (INIS)

    Wang, Naiguang; Wang, Richu; Peng, Chaoqun; Peng, Bing; Feng, Yan; Hu, Chengwang

    2014-01-01

    Highlights: • We investigate the effect of indium on the discharge behaviour of Mg-Al-Pb alloy. • We evaluate the performance of Mg-air batteries with Mg-Al-Pb and Mg-Al-Pb-In anodes. • We analyze the activation mechanism of Mg-Al-Pb-In alloy in the discharge process. - Abstract: The discharge behaviour of Mg-Al-Pb and Mg-Al-Pb-In alloys in 3.5 wt.% NaCl solution is investigated by electrochemical techniques, and compared with that of pure magnesium. The results show that Mg-Al-Pb-In alloy provides a more negative potential and exhibits a higher utilization efficiency in contrast with Mg-Al-Pb alloy and pure magnesium during the half-cell test at a large current density, and gives desirable discharge performance when used as anode for Mg- air battery. The peak power density of the Mg-air battery with Mg-Al-Pb-In anode is 94.5 mW cm −2 , which is comparable with those of Mg-H 2 O 2 semi-fuel batteries. Moreover, the activation mechanism of Mg-Al-Pb-In alloy during the discharge process is also analyzed

  11. Proton resonance elastic scattering of $^{30}$Mg for single particle structure of $^{31}$Mg

    CERN Multimedia

    The single particle structure of $^{31}$Mg, which is located in the so-called “island of inversion”, will be studied through measuring Isobaric Analog Resonances (IARs) of bound states of $^{31}$Mg. They are located in the high excitation energy of $^{31}$Al. We are going to determine the spectroscopic factors and angular momenta of the parent states by measuring the excitation function of the proton resonance elastic scattering around 0 degrees in the laboratory frame with around 3 MeV/nucleon $^{30}$Mg beam. The present study will reveal the shell evolution around $^{32}$Mg. In addition, the spectroscopic factor of the (7/2)$^{−}$ state which was not yet determined experimentally, may allow one to study the shape coexistence in this nucleus.

  12. Applications of thermodynamic calculations to Mg alloy design: Mg-Sn based alloy development

    International Nuclear Information System (INIS)

    Jung, In-Ho; Park, Woo-Jin; Ahn, Sang Ho; Kang, Dae Hoon; Kim, Nack J.

    2007-01-01

    Recently an Mg-Sn based alloy system has been investigated actively in order to develop new magnesium alloys which have a stable structure and good mechanical properties at high temperatures. Thermodynamic modeling of the Mg-Al-Mn-Sb-Si-Sn-Zn system was performed based on available thermodynamic, phase equilibria and phase diagram data. Using the optimized database, the phase relationships of the Mg-Sn-Al-Zn alloys with additions of Si and Sb were calculated and compared with their experimental microstructures. It is shown that the calculated results are in good agreement with experimental microstructures, which proves the applicability of thermodynamic calculations for new Mg alloy design. All calculations were performed using FactSage thermochemical software. (orig.)

  13. Green emission from ZnO–MgO nanocomposite due to Mg diffusion at the interface

    International Nuclear Information System (INIS)

    Sowri Babu, K.; Ramachandra Reddy, A.; Venugopal Reddy, K.

    2015-01-01

    The origin and electronic transitions responsible for green emission observed from ZnO–MgO nanocomposite are investigated. The photoluminescence (PL) spectrum of ZnO–MgO nanocomposite annealed at 600 °C showed only a sharp and intense UV emission peak centered at 396 nm. As the annealing temperature increased from 600 °C to 1000 °C, the green emission positioned at 503 nm is emerged and its intensity enhanced gradually and reached maximum value at 900 °C and then decreased at 1000 °C. It is observed that both UV and green emission intensities are enhanced with variation of atomic ratio (Zn/Mg=1.52, 0.50, 0.30, 0.21, 0.15). Our experiments confirmed that the enhancement of green emission intensity is due to the formation of oxygen vacancies (V o ) due to Mg doping at the interface of ZnO and MgO. This experimental observation is in good agreement with the recent theoretical predictions which states that Mg doping in ZnO lowers the formation energies of oxygen vacancies (V o ) and zinc interstitials (Zn i ) significantly. PL excitation and emission spectra analysis reveals that excited state for both UV and green emissions is same and lies 0.24 eV below the conduction band of ZnO. Hence, the green emission is attributed to the transition of an electron form the shallow donor (defect level of Zn i ) to the deep acceptor (defect level of V o ). - Highlights: • It is found that the UV emission intensity from ZnO–MgO nanocomposite enhanced with increase of Mg concentration. • The intensity of the green emission is enhanced gradually as the temperature increased from 600 °C to 900 °C and then decreased at 1000 °C. • The effect of Mg concentration, MgO, strain at the interface on green emission is investigated. • These experiments confirmed that green emission is due to the oxygen vacancies created in ZnO due to the Mg doping at the interface and it is in good agreement with the theoretical predictions. • The decrease of green emission intensity is

  14. Corrosion analysis of AlMg2 and AlMgSi using electrochemical method

    International Nuclear Information System (INIS)

    Dian A; Maman Kartaman; Rosika K; Yanlinastuti

    2014-01-01

    Corrosion test of cladding materials and structures of research reactor fuel, AlMgSi and AlMg2 have been performed in demineralized water of pH 2 and 6.7 using an electrochemical method. Corrosion phenomenon is affected by several factor such as composition and condition of solution. The purpose of this activity is to investigate the corrosion phenomena through the determination of the parameters of corrosion and polarization curve. The materials used are AlMg2 and AlMgSi alloy in circular dish shape with an area of 1 Cm"2. Preparation of the test sample is performed through several stages polishing, cleaning and drying procedures followed ASTM G3. The electrochemical method is done by measuring the open circuit potential (OCP), polarization resistance and potentiodynamic in demineralized water of pH 2 and pH 6.7 at temperature of 25°C. The results of the OCP is the corrosion potential (Ecorr) of AlMg2 and AlMgSi each of -906.1 mV and -619.8 mV at pH 2 and -868.6 and -756.7 mV at pH 6.7 mV. The results of measurements by polarization resistance technique showed that the corrosion rate of AlMg2 and AlMgSi in safe category (<2 mpy) at pH 6.7 and at pH 2 corrosion rate increased significantly, but still in the lightweight category (<20 mpy). Potentiodynamic curves showed that the passivation at pH 6.7 is very low while the passivation at pH 2 occurs within a relatively short range potential and followed events corroded. (author)

  15. A study on preparation and hydriding of β-Mg2Al3 and γ-Mg17Al12

    International Nuclear Information System (INIS)

    Hadi Suwarno

    2009-01-01

    The mechanism of the synthetic formation of β-Mg 2 Al 3 and γ-Mg 17 Al 12 has been studied. Mechanical alloying of Mg and Al powders with the atomic ratio of Mg:Al = 2:3 in toluene solution yields β-Mg 2 Al 3 compound after milling for 30 h. The γ-Mg 17 Al 12 can be formed by heating the β-Mg 2 Al 3 at 430°C under high vacuum. The measured hydrogen capacities of β-Mg 2 Al 3 and γ-Mg 17 Al 12 as hydride at 300°C are 3.2 and 4.9 wt%, respectively. Microstructure of the Mg-Al specimen shows that on hydriding at 300°C the polygonal shape of the γ-Mg 17 Al 12 changes into irregular shapes which are composed of γ-MgH 2 and Al. (author)

  16. Hydrogen absorption kinetics and structural properties of Mg85Ni10Ca5 and Mg90Ni10

    International Nuclear Information System (INIS)

    Aoki, Masakazu; Saito, Katsushi; Towata, Shin-ichi

    2005-01-01

    Mg 85 Ni 10 Ca 5 and Mg 90 Ni 10 were prepared by melting mixtures of the elements in mild steel crucibles and pouring them into copper molds. Hydrogen absorption kinetics and structural properties of the alloys were characterized by the volumetric method using a Sievert's apparatus, X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The crystallite size of Mg in Mg 85 Ni 10 Ca 5 , which is evaluated by XRD peak broadening, is about 50% smaller than that in Mg 90 Ni 10 . In addition, the nanometer-scale structure composed of Mg, Mg 2 Ni, Mg 2 Ca was observed in Mg 85 Ni 10 Ca 5 . Mg 85 Ni 10 Ca 5 shows better hydrogen absorption kinetics than Mg 90 Ni 10 in the temperature range of room temperature to 573 K. The better absorption kinetics of Mg 85 Ni 10 Ca 5 is mainly attributed to the nanometer-scale structure

  17. Reconstructive structural phase transitions in dense Mg

    International Nuclear Information System (INIS)

    Yao Yansun; Klug, Dennis D

    2012-01-01

    The question raised recently about whether the high-pressure phase transitions of Mg follow a hexagonal close-packed (hcp) → body centered cubic (bcc) or hcp → double hexagonal close-packed (dhcp) → bcc sequence at room temperature is examined by the use of first principles density functional methods. Enthalpy calculations show that the bcc structure replaces the hcp structure to become the most stable structure near 48 GPa, whereas the dhcp structure is never the most stable structure in the pressure range of interest. The characterized phase-transition mechanisms indicate that the hcp → dhcp transition is also associated with a higher enthalpy barrier. At room temperature, the structural sequence hcp → bcc is therefore more energetically favorable for Mg. The same conclusion is also reached from the simulations of the phase transitions using metadynamics methods. At room temperature, the metadynamics simulations predict the onset of a hcp → bcc transition at 40 GPa and the transition becomes more prominent upon further compression. At high temperatures, the metadynamics simulations reveal a structural fluctuation among the hcp, dhcp, and bcc structures at 15 GPa. With increasing pressure, the structural evolution at high temperatures becomes more unambiguous and eventually settles to a bcc structure once sufficient pressure is applied. (paper)

  18. Phase formation in Mg-Sn-Si and Mg-Sn-Si-Ca alloys

    Energy Technology Data Exchange (ETDEWEB)

    Kozlov, A.; Groebner, J. [Institute of Metallurgy, Clausthal University of Technology, Robert-Koch-Str. 42, D-38678 Clausthal-Zellerfeld (Germany); Schmid-Fetzer, R., E-mail: schmid-fetzer@tu-clausthal.de [Institute of Metallurgy, Clausthal University of Technology, Robert-Koch-Str. 42, D-38678 Clausthal-Zellerfeld (Germany)

    2011-02-17

    Research highlights: > The solidification paths of ternary and quaternary alloys are analyzed in detail, using the tool of thermodynamic calculations. > The precipitation sequence of phases and their amounts compare well with the microstructure of alloys. > The most efficient comparison to the experimental thermal analysis data is done by calculation of the enthalpy variation with temperature. > The viability of a procedure for the selection of multicomponent key samples is demonstrated for the development of the Mg-Ca-Si-Sn phase diagram. - Abstract: Experimental work is done and combined with the Calphad method to generate a consistent thermodynamic description of the Mg-Ca-Si-Sn quaternary system, validated for Mg-rich alloys. The viability of a procedure for the selection of multicomponent key samples is demonstrated for this multicomponent system. Dedicated thermal analysis with DTA/DSC on sealed samples is performed and the microstructure of slowly solidified alloys is analyzed using SEM/EDX. The thermodynamic description and phase diagram of the ternary Mg-Si-Sn system, developed in detail also in this work, deviates significantly from a previous literature proposal. The phase formation in ternary and quaternary alloys is analyzed using the tool of thermodynamic equilibrium and Scheil calculations for the solidification paths and compared with present experimental data. The significant ternary/quaternary solid solubilities of pertinent intermetallic phases are quantitatively introduced in the quaternary Mg-Ca-Si-Sn phase diagram and validated by experimental data.

  19. Half-life determination for 27Mg

    Science.gov (United States)

    Zahn, G. S.; Genezini, F. A.

    2015-07-01

    In this work, the half-life of the short-lived magnesium radionuclide 27Mg was measured by following the activity of samples after they were irradiated in the IEA-R1 reactor. An exponential decay function was then fitted to the results using the counts from a 60Co source as livetime chronometer; the individual half-life values obtained for each irradiation were compiled using both the usual unweighted and σ-2-weighted averages, as well as the robust averages obtained using the Normalized Residuals and the Rajeval techniques. The final halflive values obtained aren't compatible with the ENSDF compilation values, but have a similar uncertainty; analysis of the experimental literature values, all from the 50’s-60’s, show that further measurements should be undertaken in order to achieve a more robust consensus value for this half-life.

  20. Experimental lifetimes for Mg-like chlorine

    International Nuclear Information System (INIS)

    Engstroem, L.; Bengtsson, P.; Jupen, C.; Livingston, A.E.; Martinson, I.

    1995-01-01

    The results of beam-foil measurements of lifetimes for low-lying singlet levels in Mg-like chlorine, Cl VI, are presented. The decay curves were analyzed by means of the arbitrarily normalized decay curve method, combined with the recently developed CANYL code, which facilitates studies of decay chains. Cascade corrected data are presented for the levels 3s3p 1 P, 3p 2 1 S, 3p 2 1 D, and 3s3d 1 D, whereas less rigorous lifetime values, based on curve fits, were obtained for the 3p3d 1 D, 3p3d 1 F, and 3s4f 1 F levels. The data are in excellent agreement with recent theoretical values, and previous discrepancies between experiment and theory for short-lived states have been removed

  1. MgO by injection CVD

    International Nuclear Information System (INIS)

    Abrutis, A.; Kubilius, V.; Teiserkis, A.; Bigelyte, V.; Vengalis, B.; Jukna, A.; Butkute, R.

    1997-01-01

    Epitaxial YBa 2 Cu 3 O 7 layers with 45 in-plane orientation have been grown by injection CVD on MgO substrates polished off-axis to within 1.4-1.9 of the [100] direction. This new single-source CVD process is based on computer-controlled injection of precise microdoses of a metal-organic precursor solution into a CVD reactor. A wide range of solution compositions was tested to investigate compositional effects on phase purity, surface morphology, texturing and superconducting properties of the prepared films. The highest quality films with pure 45 texture had a smooth surface, zero resistance T c (R=0) of 88-89 K, and critical current density J c (77 K) above 10 6 A/cm 2 . (orig.) and critical current density J c (77 K) above 10 6 A/cm 2 . (orig.)

  2. The three shapes of 32Mg

    International Nuclear Information System (INIS)

    Poves, A.; Nowacki, F.; Caurier, E.

    2014-01-01

    The N=20 and N=28 'islands of inversion' are described by large scale shell model calculations which mix configurations with different Nℎω or equivalently with different number of particles promoted from the sd-shell to the p f-shell. We pay particular attention to the properties of the states at fix Nℎω which turn out to be the real protagonists of the physics at N=20. In particular we study the appearance of spherical, deformed and superdeformed structures in 32 Mg at fixed 0p-0h, 2p-2h and 4p-4h configurations. Finally we show that the islands of deformation at N=20 and N=28 merge in a single one for Magnesium isotopes. (authors)

  3. Mg amorphous alloys for biodegradable implants

    International Nuclear Information System (INIS)

    Danez, G.P.; Koga, G.Y.; Tonucci, S.; Bolfarini, C.; Kiminami, C.S.; Botta Filho, W.J.

    2010-01-01

    The use of implants made from amorphous alloys magnesium-based with additions of zinc and calcium are promising. Properties such as biocompatibility, low density, high mechanical strength, low modulus (as compared to alloys such as stainless steel and titanium), corrosion resistance and wear resistance make it attractive for use in implants. Moreover, the by-products of corrosion and wear are not toxic and may contribute to fixation. Aiming to understand the tendency of this amorphous ternary (Mg-Zn-Ca) and expand the information about this system, this work involved the use of the topological criterion of instability (λ) and the criterion of electronegativity (Δe) to the choice of compositions. The alloys were processed into wedge-shaped and analyzed structurally and in X-ray diffraction and scanning electron microscopy. (author)

  4. Estabilidad de tabletas de Rifampicina 300 mg

    Directory of Open Access Journals (Sweden)

    Lisette Martínez Miranda

    2001-04-01

    Full Text Available Se realizó el estudio de estabilidad de las tabletas de rifampicina 300 mg. Se utilizó para la cuantificación del principio activo un método analítico desarrollado y validado por cromatografía líquida de alta resolución en fase reversa y detección ultravioleta. El estudio de estabilidad de las tabletas se efectuó mediante los métodos de vida útil y acelerado en condiciones isotérmicas; no se obtuvo una variación notable de la concentración en el tiempo de estudio y se demostró así la estabilidad química y térmica del principio activo, por lo que se proponen 2 años como fecha de vencimiento. La humedad relativa de 75, 84 y 92 % tuvo influencia en la estabilidad de la formulación en el período analizado.The stability study of rifampicin 300 mg was conducted. An analytical method developed and validated by high pressure liquid chromatography in reverse phase and ultraviolet detection was used for the quantification of the actives principle. The stability study of the tablets was conducted by the method of useful life and the accelerated method under isothermic conditions. There was no significant variation of the concentration during the time of study and, thus, the chemical and thermal stability of the active principle was proved. A period of 2 years was proposed as expiration date. A relative humidity of 75, 84 and 92% influenced on the stability of the formulation in the analyzed period.

  5. Hydriding and dehydriding rates of Mg, Mg-10TaF5, and Mg-10NbF5 prepared via reactive mechanical grinding

    Science.gov (United States)

    Song, Myoung Youp; Kwak, Young Jun; Lee, Seong Ho; Park, Hye Ryoung

    2015-01-01

    In this work, TaF5 and NbF5 were chosen as additives to enhance the hydriding and dehydriding rates of Mg. Mg, Mg-10TaF5, and Mg-10NbF5 samples were prepared by reactive mechanical grinding. The hydriding and dehydriding properties of the samples were then examined. Mg-10TaF5 had the largest amount of hydrogen absorbed for 30 min and the highest initial dehydriding rate after incubation period, followed in order by Mg-10NbF5, and Mg. At 593 K under 12 bar H2 at the first cycle, Mg-10TaF5 absorbed 3.63 wt% H for 5 min and 4.53 wt% H for 30 min. At 593 K under 1.0 bar H2 at the first cycle, Mg-10TaF5 desorbed 0 wt% H for 2.5 min, 0.59 wt% H for 5 min, 3.42 wt% H for 30 min, and 4.24 wt% H for 60 min. The reactive mechanical grinding of Mg with TaF5 or NbF5 is believed to have facilitated the nucleation and to have decreased the diffusion distances of hydrogen atoms. These two effects are believed to have increased the hydriding and dehydriding rates of Mg. The MgF2 and Ta2H formed in Mg-10TaF5, and the MgF2, NbH2, and NbF3 formed in Mg-10NbF5 are considered to have enhanced both of these effects.

  6. Mechanochemical Synthesis of Nanostructured MgXNi1-XO Compound by Mg-NiO Mixture

    Directory of Open Access Journals (Sweden)

    Nader Setoudeh

    2017-06-01

    Full Text Available Synthesis of magnesium nickel oxide phase such as MgxNi1-xO solid solutions has been studied in this research article using mechnochmical reaction between magnesium and nickel oxide. Mixtures of magnesium powder and nickel oxide (Mg+NiO with stoichiometric compositions were milled for different times in a planetary ball mill. Reduction reaction of nickel oxide by magnesium via a mechanically induced self-sustaining reaction (MSR was confirmed in the XRD measurements of the as-milled samples. Formation of nanostructured magnesium nickel oxide phases (such as Mg0.4Ni0.6O or MgNiO2 was observed after isothermal heating of the 30 minutes milled samples at 1000°C where nickel phase seems to disappear in XRD patterns. The traces of phases such as Mg0.4Ni0.6O or MgNiO2 were also observed in the as-milled mixtures. Therefore, the XRD results of the as-milled samples suggested that the formation of magnesium nickel oxide phases could be possible even after prolonged milling. The XRD and SEM results of both as-milled and isothermally heated samples indicated that the crystallite size and particle size of the final products reached to nanoscale after milling. Morphological and compositional evolution of the samples after heat treatment was monitored through SEM imaging and elemental analyses. The results confirmed that the composition of final product is close to Mg0.4Ni0.6O compound.

  7. Porous composite materials ZrO2(MgO)-MgO for osteoimplantology

    International Nuclear Information System (INIS)

    Buyakov, Ales; Litvinova, Larisa; Shupletsova, Valeria; Kulbakin, Denis; Kulkov, Sergey

    2016-01-01

    The pore structure and phase composition of ceramic composite material ZrO 2 (Mg)-MgO at different sintering temperatures were studied. The main mechanical characteristics of the material were determined and it was shown that they are close to the characteristics of natural bone tissues. It was shown that material structure has a positive effect on the pre-osteoblast cells proliferation. In-vitro studies of pre-osteoblast cells, cultivation on material surface showed a good cell adhesion, proliferation and differentiation of MMSC by osteogenic type.

  8. Sorption of selenium on Mg-Al and Mg-Al-Eu layered double hydroxides

    International Nuclear Information System (INIS)

    Curtius, H.; Paparigas, Z.; Kaiser, G.

    2008-01-01

    Salt domes represent deep geological formations which are under consideration as final repositories for irradiated research reactor fuel elements. For long-term safety aspects the mobilisation of the radionuclides due to a water ingress is intensively investigated. At the Institute of Energy Research (IEF-6), leaching experiments were performed in a hot cell facility with UAl x -Al and U 3 Si 2 -Al dispersed research reactor fuel elements in repository-relevant MgCl 2 -rich salt brines under anaerobic conditions. The fuel plates corroded completely within one year and a Mg-Al-layered double hydroxide (LDH) with chloride as interlayer anion was identified as one crystalline phase component of the corrosion products (secondary phases). This Mg-Al-LDH was synthesized, characterized, and the ability to retard europium by an incorporation process was investigated. Europium, as a representative for lanthanides, was identified to be one of the radionuclides which were found in the corrosion products. We could show that europium was incorporated in the lattice structure. LDHs have high anion exchange capacities that enhance their potential to remove anionic contaminants from aqueous systems. In this work the sorption behaviour of selenium in the chemical form as selenite (SeO 3 2- ) on Mg-Al-LDH and on Mg-Al-Eu-LDH was investigated. Especially the influence of the larger europium-III ion was of interest. It represents in the Mg-Al-Eu-LDH about 10% of the molar aluminium amount. The sorption has been experimentally studied in a wide range of pH, ionic strength, radionuclide and sorbent concentration. Both LDHs with chloride as interlayer anion were synthesized by a coprecipitation method under controlled conditions, and their main physico-chemical properties were analyzed prior to the sorption experiments. The sorption kinetics of selenite on the LDHs in water and in MgCl 2 -rich brine were rapid using a LDH concentration of 10 g/L. Equilibrium, indicated by stable p

  9. Porous composite materials ZrO{sub 2}(MgO)-MgO for osteoimplantology

    Energy Technology Data Exchange (ETDEWEB)

    Buyakov, Ales, E-mail: alesbuyakov@gmail.com [Institute of Strength Physics and Materials Science SB RAS, Tomsk, 634055 (Russian Federation); National Research Tomsk State University, Tomsk, 634050 (Russian Federation); Litvinova, Larisa, E-mail: larisalitvinova@yandex.ru; Shupletsova, Valeria, E-mail: vshupletsova@mail.ru [Immanuel Kant Baltic Federal University, Kaliningrad (Russian Federation); Kulbakin, Denis, E-mail: kulbakin2012@gmail.com [Tomsk Cancer Research Institute, Tomsk, 634050 (Russian Federation); Kulkov, Sergey, E-mail: kulkov@ispms.ru [Institute of Strength Physics and Materials Science SB RAS, Tomsk, 634055 (Russian Federation); National Research Tomsk State University, Tomsk, 634050 (Russian Federation); National Research Tomsk Polytechnic University, Tomsk, 634050 (Russian Federation)

    2016-08-02

    The pore structure and phase composition of ceramic composite material ZrO{sub 2}(Mg)-MgO at different sintering temperatures were studied. The main mechanical characteristics of the material were determined and it was shown that they are close to the characteristics of natural bone tissues. It was shown that material structure has a positive effect on the pre-osteoblast cells proliferation. In-vitro studies of pre-osteoblast cells, cultivation on material surface showed a good cell adhesion, proliferation and differentiation of MMSC by osteogenic type.

  10. Role of dopants in LiF:Mg,Cu, LiF:Mg,P and LiF:Mg,Cu,P detectors

    International Nuclear Information System (INIS)

    Mohammadi, Kh.; Moussavi Zarandi, A.; Afarideh, H.; Shahmaleki, S.

    2013-01-01

    In this study, electronic structure of LiF crystal doped with Mg,Cu,P impurities was studied with WIEN2k code on the basis of FPLAPW+lo method. Results show that in Mg-doped LiF composition, an electronic trap was created with impurity concentration of 1.56% and 3.125%. In this condition, the electronic trap with increasing the percentage of the impurities up to 4.687% is annihilated. It was found, that by doping of Mg and Cu or P simultaneously, a hole-trap is created in valence band. It was realized that in LiF:Mg,Cu, LiF:Mg,P and LiF:Mg,Cu,P, Cu impurity and Li atom, have a key role in creation of levels which lead to create electronic and hole traps. Mg impurity and F atom, only have a role in creation of electronic traps. In addition, P impurity has a main role in creation of the electronic and hole traps in LiF:Mg,Cu,P. The activation energy of electronic and hole trap in LiF:Mg,Cu, LiF:Mg,P and LiF:Mg,Cu,P crystalline lattice were obtained as 0.3 and 5.5 eV, 0.92 and 3.4 eV and 0.75 and 3.1 eV, respectively. - Graphical abstract: Figure (a) and (b) shows changes in electronic structure and band gap energy of LiF crystal due to presence of Mg and Cu, Mg and P ions respectively. - Highlights: • Electronic structure of LiF, LiF:Mg,Cu, LiF:Mg,P and LiF:Mg,Cu,P materials were studied with WIEN2K code. • In LiF:Mg,Cu and LiF:Mg,Cu,P, Li atom and Cu impurity have a key role in creation of levels. • F atom and Mg impurity only have a role in creation of electronic traps. • In LiF:Mg,Cu,P, P impurity has a main role in creation of electronic and hole traps

  11. Ab initio study of MgH2 formation

    International Nuclear Information System (INIS)

    Novakovic, Nikola; Matovic, Ljiljana; Novakovic, Jasmina Grbovic; Manasijevic, Miodrag; Ivanovic, Nenad

    2009-01-01

    Even if there is considerable literature dealing with structure and properties of MgH 2 compound there are still some uncertain details about nature of bonding governing its formation and decomposition. In order to better understand the processes essential for absorption and desorption of MgH 2 , ab initio DFT based calculations of rutile MgH 2 compound, elemental hcp-Mg, and three different hypothetical hcp-Mg-derived hydrides are performed. Our findings show that all structures are unstable, and that MgH (Wurtzite) is a closest possible candidate for intermediate phase between the hcp-Mg and MgH 2 at 1:1 stoichiometry. An alternative hydration pathway is suggested, including promotion of hcp-Mg to bcc-Mg and consecutive transformation to rutile MgH 2 by means of hydrogen incorporation into Mg matrix. Rutile MgH 2 calculations with various hydrogen vacancies concentration are performed. Calculation shows that at high hydrogen concentration close to 1:2, stable substoichiometric hydride is possible. Calculation also shows that high vacancy (low hydrogen) concentration favors bcc-Mg 2 H over rutile Mg 2 H structure.

  12. The Influence of MgH2 on the Assessment of Electrochemical Data to Predict the Degradation Rate of Mg and Mg Alloys

    Directory of Open Access Journals (Sweden)

    Wolf-Dieter Mueller

    2014-06-01

    Full Text Available Mg and Mg alloys are becoming more and more of interest for several applications. In the case of biomaterial applications, a special interest exists due to the fact that a predictable degradation should be given. Various investigations were made to characterize and predict the corrosion behavior in vitro and in vivo. Mostly, the simple oxidation of Mg to Mg2+ ions connected with adequate hydrogen development is assumed, and the negative difference effect (NDE is attributed to various mechanisms and electrochemical results. The aim of this paper is to compare the different views on the corrosion pathway of Mg or Mg alloys and to present a neglected pathway based on thermodynamic data as a guideline for possible reactions combined with experimental observations of a delay of visible hydrogen evolution during cyclic voltammetry. Various reaction pathways are considered and discussed to explain these results, like the stability of the Mg+ intermediate state, the stability of MgH2 and the role of hydrogen overpotential. Finally, the impact of MgH2 formation is shown as an appropriate base for the prediction of the degradation behavior and calculation of the corrosion rate of Mg and Mg alloys.

  13. The role of MgO content in ex situ MgB2 wires

    DEFF Research Database (Denmark)

    Kovac, P.; Hugek, I.; Meligek, T.

    2004-01-01

    An experimental study of the effect of MgO content in the MgB2 powder used for ex situ made composite wires was carried out. Two single-core MgB2/Fe/Cu wires were made using commercial MgB2 powders from Alfa Aesar containing different fraction of MgO. Critical temperature and critical currents of...

  14. Positron annihilation study of formation of Mg vacancy in MgO

    International Nuclear Information System (INIS)

    Mizuno, M.; Araki, H.; Shirai, Y.; Inoue, Y.; Sugita, K.; Mizoguchi, T.; Tanaka, I.; Adachi, H.

    2004-01-01

    We have investigated the formation of Mg vacancy induced by ultra-dilute trivalent impurities in MgO by a combination of positron annihilation measurement and theoretical calculations of positron lifetimes. The undoped MgO yields the shortest positron lifetime of 130 ps that is shorter than that of 166 ps previously reported using a single crystal sample. The positron lifetime of the doped samples increases with the increase of the Al or Ga dopant concentration and is saturated at around 170 ps. This result indicates that the previously reported value of 166 ps is ascribed to not the bulk but the vacancy state induced by impurities. The experimental bulk lifetime of 130 ps, which is obtained by employing trapping model, is well reproduced by the theoretical calculation using the semiconductor model. The calculated defect lifetime is about 20 ps longer than the experimental value. This may be due to the lattice relaxation around Mg vacancy associated with the trapping of positrons. (orig.)

  15. Positron annihilation study of formation of Mg vacancy in MgO

    Energy Technology Data Exchange (ETDEWEB)

    Mizuno, M.; Araki, H.; Shirai, Y. [Science and Technology Center for Atoms, Molecules and Ions Control, Osaka Univ., Osaka (Japan); Inoue, Y.; Sugita, K. [Dept. of Materials Science and Engineering, Osaka Univ., Osaka (Japan); Mizoguchi, T.; Tanaka, I.; Adachi, H. [Dept. of Materials Science and Engineering, Kyoto Univ., Kyoto (Japan)

    2004-07-01

    We have investigated the formation of Mg vacancy induced by ultra-dilute trivalent impurities in MgO by a combination of positron annihilation measurement and theoretical calculations of positron lifetimes. The undoped MgO yields the shortest positron lifetime of 130 ps that is shorter than that of 166 ps previously reported using a single crystal sample. The positron lifetime of the doped samples increases with the increase of the Al or Ga dopant concentration and is saturated at around 170 ps. This result indicates that the previously reported value of 166 ps is ascribed to not the bulk but the vacancy state induced by impurities. The experimental bulk lifetime of 130 ps, which is obtained by employing trapping model, is well reproduced by the theoretical calculation using the semiconductor model. The calculated defect lifetime is about 20 ps longer than the experimental value. This may be due to the lattice relaxation around Mg vacancy associated with the trapping of positrons. (orig.)

  16. Surface treatments for controlling corrosion rate of biodegradable Mg and Mg-based alloy implants

    International Nuclear Information System (INIS)

    Uddin, M S; Hall, Colin; Murphy, Peter

    2015-01-01

    Due to their excellent biodegradability characteristics, Mg and Mg-based alloys have become an emerging material in biomedical implants, notably for repair of bone as well as coronary arterial stents. However, the main problem with Mg-based alloys is their rapid corrosion in aggressive environments such as human bodily fluids. Previously, many approaches such as control of alloying materials, composition and surface treatments, have been attempted to regulate the corrosion rate. This article presents a comprehensive review of recent research focusing on surface treatment techniques utilised to control the corrosion rate and surface integrity of Mg-based alloys in both in vitro and in vivo environments. Surface treatments generally involve the controlled deposition of thin film coatings using various coating processes, and mechanical surfacing such as machining, deep rolling or low plasticity burnishing. The aim is to either make a protective thin layer of a material or to change the micro-structure and mechanical properties at the surface and sub-surface levels, which will prevent rapid corrosion and thus delay the degradation of the alloys. We have organised the review of past works on coatings by categorising the coatings into two classes—conversion and deposition coatings—while works on mechanical treatments are reviewed based on the tool-based processes which affect the sub-surface microstructure and mechanical properties of the material. Various types of coatings and their processing techniques under two classes of coating and mechanical treatment approaches have been analysed and discussed to investigate their impact on the corrosion performance, biomechanical integrity, biocompatibility and cell viability. Potential challenges and future directions in designing and developing the improved biodegradable Mg/Mg-based alloy implants were addressed and discussed. The literature reveals that no solutions are yet complete and hence new and innovative approaches

  17. Efficacy of 5MG and 10MG rosuvastatin in type-2 diabetes mellitus with hypercholesteroalemia

    International Nuclear Information System (INIS)

    Ullah, F.; Rahim, F.; Rahman, S.U.; Ashfaq, M.; Afridi, A.K.

    2015-01-01

    Background: Coronary Heart Disease (CHD) is the most important complication and the leading cause of death in patients with type 2 diabetes mellitus (T2DM). Hypercholesterolemia is an important modifiable risk factor for CHD. Statins are the first line drugs for the treatment of hypercholesterolemia in DM. Comparative studies between different statins are available but different doses of the same statin have not been compared in our population. The objective of this study is to compare mean reduction in serum LDL-C level after using 5mg and 10mg of rosuvastatin among T2DM patients with hypercholesterolemia. This study will help finding lowest effective dose of rosuvastatin to achieve internationally set low density lipoprotein cholesterol (LDL-C) goals. Method: A total of 82 patients with T2DM having fasting LDL-C levels equal or more than 100mg/dl were randomly allocated into two groups with 41 patients in each group. Baseline fasting serum LCL-C levels were obtained in all patients. Group A received 5mg while group B received 10mg of rosuvastatin daily at night. After 6 weeks, fasting LDL-C levels were obtained and analysed to compare the mean±SD reduction of LDL-C levels in both groups. Results: Baseline mean±SD LDL-C levels in group A and group B were 134.12±30.02 and 143.49±32.01 respectively (p 0.176). Follow up mean ± SD LDL-C levels were 81.59±28.47 and 83.24±36.06 respectively (p 0.818). Mean ± SD reduction in LDL-C levels from baseline levels in group A and group B were 52.51±19.49 and 60.20±24.09 (p 0.116). Conclusion: Rosuvastatin 5mg is as effective as 10mg in reducing the LDL-C levels in type 2 diabetic patients with hypercholesterolemia. (author)

  18. Surface treatments for controlling corrosion rate of biodegradable Mg and Mg-based alloy implants

    Science.gov (United States)

    Uddin, M S; Hall, Colin; Murphy, Peter

    2015-01-01

    Due to their excellent biodegradability characteristics, Mg and Mg-based alloys have become an emerging material in biomedical implants, notably for repair of bone as well as coronary arterial stents. However, the main problem with Mg-based alloys is their rapid corrosion in aggressive environments such as human bodily fluids. Previously, many approaches such as control of alloying materials, composition and surface treatments, have been attempted to regulate the corrosion rate. This article presents a comprehensive review of recent research focusing on surface treatment techniques utilised to control the corrosion rate and surface integrity of Mg-based alloys in both in vitro and in vivo environments. Surface treatments generally involve the controlled deposition of thin film coatings using various coating processes, and mechanical surfacing such as machining, deep rolling or low plasticity burnishing. The aim is to either make a protective thin layer of a material or to change the micro-structure and mechanical properties at the surface and sub-surface levels, which will prevent rapid corrosion and thus delay the degradation of the alloys. We have organised the review of past works on coatings by categorising the coatings into two classes—conversion and deposition coatings—while works on mechanical treatments are reviewed based on the tool-based processes which affect the sub-surface microstructure and mechanical properties of the material. Various types of coatings and their processing techniques under two classes of coating and mechanical treatment approaches have been analysed and discussed to investigate their impact on the corrosion performance, biomechanical integrity, biocompatibility and cell viability. Potential challenges and future directions in designing and developing the improved biodegradable Mg/Mg-based alloy implants were addressed and discussed. The literature reveals that no solutions are yet complete and hence new and innovative approaches

  19. Comparison of initial loading doses of 5 mg and 10 mg for warfarin therapy

    Directory of Open Access Journals (Sweden)

    Sidnei Lastória

    2014-03-01

    Full Text Available CONTEXT: The question of what is the best loading dosage of warfarin when starting anticoagulant treatment has been under discussion for ten years. We were unable to find any comparative studies of these characteristics conducted here in Brazil. OBJECTIVE: To compare the safety and efficacy of two initial warfarin dosage regimens for anticoagulant treatment. METHODS: One-hundred and ten consecutive patients of both sexes, with indications for anticoagulation because of venous or arterial thromboembolism, were analyzed prospectively. During the first 3 days of treatment, these patients were given adequate heparin to keep aPTT (activated partial thromboplastin time between 1.5 and 2.5, plus 5 mg of warfarin. From the fourth day onwards, their warfarin doses were adjusted using International Normalized Ratios (INR; target range: 2 to 3. This prospective cohort was compared with a historical series of 110 patients had been given 10 mg of warfarin on the first 2 days and 5 mg on the third day with adjustments based on INR thereafter. Outcomes analyzed were as follows: recurrence of thromboembolism, bleeding events and time taken to enter the therapeutic range. RESULTS: Efficacy, safety and length of hospital stay were similar in both samples. The sample that were given 10 mg entered the therapeutic range earlier (means: 4.5 days vs. 5.8 days, were on lower doses at discharge and had better therapeutic indicators at the first return appointment. CONCLUSIONS: The 10 mg dosage regimen took less time to attain the therapeutic range and was associated with lower warfarin doses at discharge and better INR at first out-patients follow-up visit.

  20. Performance of Mg-14Li-1Al-0.1Ce as anode for Mg-air battery

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Yibin; Li, Deyu [School of Chemical Engineering and Technology, Harbin Institute of Technology, West Street No. 92, Harbin 150001 (China); Li, Ning [School of Chemical Engineering and Technology, Harbin Institute of Technology, West Street No. 92, Harbin 150001 (China); Key Laboratory of Superlight Materials and Surface Technology, Ministry of Education, Harbin Engineering University, Harbin 150001 (China); Zhang, Milin; Huang, Xiaomei [Key Laboratory of Superlight Materials and Surface Technology, Ministry of Education, Harbin Engineering University, Harbin 150001 (China)

    2011-02-15

    In this research, a new Mg-air battery based on Mg-14Li-1Al-0.1Ce was prepared and the battery performance was investigated by constant current discharge test. The corrosion behavior of Mg, AZ31 and Mg-Li-Al-Ce were studied by self-corrosion rate measurement and potentiodynamic polarization measurement. The characteristics of Mg-Li-Al-Ce after discharge were investigated by electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM) and X-ray diffraction (XRD). The results show that Mg-Li-Al-Ce is more active than Mg and AZ31. The self-corrosion rate is found to be in the order: Mg-Li-Al-Ce < Mg < AZ31. It has been observed that the Mg-air battery based on Mg-Li-Al-Ce offers higher operating voltage, anodic efficiency and capacity than those with Mg and AZ31. SEM and EIS results show that the discharge product of Mg-Li-Al-Ce is loosely adhered to the alloy surface, and thus Mg-Li-Al-Ce could keep high discharge activity during discharge. (author)

  1. Photodissociation spectroscopy of the Mg+-acetic acid complex

    Science.gov (United States)

    Abate, Yohannes; Kleiber, P. D.

    2006-11-01

    We have studied the structure and photodissociation of Mg+-acetic acid clusters. Ab initio calculations suggest four relatively strongly bound ground state isomers for the [MgC2H4O2]+ complex. These isomers include the cis and trans forms of the Mg+-acetic acid association complex with Mg+ bonded to the carbonyl O atom of acetic acid, the Mg+-acetic acid association complex with Mg+ bonded to the hydroxyl O atom of acetic acid, or to a Mg+-ethenediol association complex. Photodissociation through the Mg+-based 3p←3s absorption bands in the near UV leads to direct (nonreactive) and reactive dissociation products: Mg+, MgOH+, Mg(H2O )+, CH3CO+, and MgCH3+. At low energies the dominant reactive quenching pathway is through dehydration to Mg(H2O)+, but additional reaction channels involving C-H and C-C bond activation are also open at higher energies.

  2. Mg-Ca Alloys Produced by Reduction of CaO: Understanding of ECO-Mg Alloy Production

    Science.gov (United States)

    Jung, In-Ho; Lee, Jin Kyu; Kim, Shae K.

    2017-04-01

    There have been long debates about the environment conscious (ECO) Mg technology which utilizes CaO to produce Ca-containing Mg alloys. Two key process technologies of the ECO-Mg process are the chemical reduction of CaO by liquid Mg and the maintenance of melt cleanliness during the alloying of Ca. Thermodynamic calculations using FactSage software were performed to explain these two key issues. In addition, an experimental study was performed to compare the melt cleanliness of the Ca-containing Mg alloys produced by the conventional route with metallic Ca and the ECO-Mg route with CaO.

  3. LOW Mg/Si PLANETARY HOST STARS AND THEIR Mg-DEPLETED TERRESTRIAL PLANETS

    Energy Technology Data Exchange (ETDEWEB)

    Carter-Bond, Jade C.; O' Brien, David P. [Planetary Science Institute, 1700 E. Fort Lowell, Tucson, AZ 85719 (United States); Delgado Mena, Elisa; Israelian, Garik; Gonzalez Hernandez, Jonay I. [Instituto de Astrofisica de Canarias, 38200 La Laguna, Tenerife (Spain); Santos, Nuno C., E-mail: j.bond@unsw.edu.au [Centro de Astrofisica, Universidade do Porto, Rua das Estrelas, 4150-762 Porto (Portugal)

    2012-03-15

    Simulations have shown that a diverse range of extrasolar terrestrial planet bulk compositions are likely to exist based on the observed variations in host star elemental abundances. Based on recent studies, it is expected that a significant proportion of host stars may have Mg/Si ratios below 1. Here we examine this previously neglected group of systems. Planets simulated as forming within these systems are found to be Mg-depleted (compared to Earth), consisting of silicate species such as pyroxene and various feldspars. Planetary carbon abundances also vary in accordance with the host star C/O ratio. The predicted abundances are in keeping with observations of polluted white dwarfs, lending validity to this approach. Further studies are required to determine the full planetary impacts of the bulk compositions predicted here.

  4. Thermodynamic properties of Mg2Si and Mg2Ge investigated by first principles method

    International Nuclear Information System (INIS)

    Wang, Hanfu; Jin, Hao; Chu, Weiguo; Guo, Yanjun

    2010-01-01

    The lattice dynamics and thermodynamic properties of Mg 2 Si and Mg 2 Ge are studied based on the first principles calculations. We obtain the phonon dispersion curves and phonon density of states spectra using the density functional perturbation theory with local density approximations. By employing the quasi-harmonic approximation, we calculate the temperature dependent Helmholtz free energy, bulk modulus, thermal expansion coefficient, specific heat, Debye temperature and overall Grueneisen coefficient. The results are in good agreement with available experimental data and previous theoretical studies. The thermal conductivities of both compounds are then estimated with the Slack's equation. By carefully choosing input parameters, especially the acoustic Debye temperature, we find that the calculated thermal conductivities agree fairly well with the experimental values above 80 K for both compounds. This demonstrates that the lattice thermal conductivity of simple cubic semiconductors may be estimated with satisfactory accuracy by combining the Slack's equation with the necessary thermodynamics parameters derived completely from the first principles calculations.

  5. Relativistic quasiparticle band structures of Mg2Si, Mg2Ge, and Mg2Sn: Consistent parameterization and prediction of Seebeck coefficients

    Science.gov (United States)

    Shi, Guangsha; Kioupakis, Emmanouil

    2018-02-01

    We apply density functional and many-body perturbation theory calculations to consistently determine and parameterize the relativistic quasiparticle band structures of Mg2Si, Mg2Ge, and Mg2Sn, and predict the Seebeck coefficient as a function of doping and temperature. The quasiparticle band gaps, including spin-orbit coupling effects, are determined to be 0.728 eV, 0.555 eV, and 0.142 eV for Mg2Si, Mg2Ge, and Mg2Sn, respectively. The inclusion of the semicore electrons of Mg, Ge, and Sn in the valence is found to be important for the accurate determination of the band gaps of Mg2Ge and Mg2Sn. We also developed a Luttinger-Kohn Hamiltonian and determined a set of band parameters to model the near-edge relativistic quasiparticle band structure consistently for all three compounds that can be applied for thermoelectric device simulations. Our calculated values for the Seebeck coefficient of all three compounds are in good agreement with the available experimental data for a broad range of temperatures and carrier concentrations. Our results indicate that quasiparticle corrections are necessary for the accurate determination of Seebeck coefficients at high temperatures at which bipolar transport becomes important.

  6. Decomposition of supersaturated solid solutions Mg-Ho and Mg-Gd

    International Nuclear Information System (INIS)

    Sukhanov, V.D.; Dobromyslov, A.V.; Rokhlin, L.L.; Dobatkina, T.V.

    2002-01-01

    Methods of electron microscopy and X-ray diffraction analysis are applied to study ageing magnesium base alloys with holmium and gadolinium. It is shown that the precipitation of supersaturated Mg base solid solutions goes through several subsequent stages and is accompanied by a considerable precipitation hardening effect at the stage of metastable phase precipitation. The influence of aging time and temperature on precipitation kinetics is established [ru

  7. Simulation of precipitation and strengthening in MG-RE alloys

    OpenAIRE

    Liu, Hong

    2017-01-01

    Magnesium - rare earth (Mg-RE) alloys have received considerable attention in the past decades for wider applications in the aerospace industry due to their relatively high strength and excellent creep resistance. Most rare-earth containing magnesium alloys, such as Mg-Y, Mg-Gd, and Mg-Y-Nd, are precipitation hardenable. A technical barrier to the wider applications of such alloys is the lack of a sufficiently large age hardening response. To further improve this response, an improved underst...

  8. Combinatorial search for hydrogen storage alloys: Mg-Ni and Mg-Ni-Ti

    Energy Technology Data Exchange (ETDEWEB)

    Oelmez, Rabia; Cakmak, Guelhan; Oeztuerk, Tayfur [Dept. of Metallurgical and Materials Engineering, Middle East Technical University, 06531 Ankara (Turkey)

    2010-11-15

    A combinatorial study was carried out for hydrogen storage alloys involving processes similar to those normally used in their fabrication. The study utilized a single sample of combined elemental (or compound) powders which were milled and consolidated into a bulk form and subsequently deformed to heavy strains. The mixture was then subjected to a post annealing treatment, which brings about solid state reactions between the powders, yielding equilibrium phases in the respective alloy system. A sample, comprising the equilibrium phases, was then pulverized and screened for hydrogen storage compositions. X-ray diffraction was used as a screening tool, the sample having been examined both in the as processed and the hydrogenated state. The method was successfully applied to Mg-Ni and Mg-Ni-Ti yielding the well known Mg{sub 2}Ni as the storage composition. It is concluded that a partitioning of the alloy system into regions of similar solidus temperature would be required to encompass the full spectrum of equilibrium phases. (author)

  9. Mg-lattice associations in red coralline algae

    Science.gov (United States)

    Kamenos, N. A.; Cusack, M.; Huthwelker, T.; Lagarde, P.; Scheibling, R. E.

    2009-04-01

    Recent investigations have shown red coralline algae to record ambient temperature in their calcite skeletons. Temperature recorded by variation in Mg concentrations within algal growth bands has sub-annual resolution and high accuracy. The conversion of Mg concentration to temperature is based on the assumption of Ca replacement by Mg within the algal calcite skeleton at higher temperatures. While Mg-temperature relationships in coralline algae have been calibrated for some species, the location of Mg within the calcite lattice remains unknown. Critically, if Mg is not a lattice component but associated with organic components this could lead to erroneous temperature records. Before coralline algae are used in large scale climate reconstructions it is therefore important to determine the location of Mg. Synchrotron Mg-X-ray absorbance near edge structure (XANES) indicates that Mg is associated with the calcite lattice in Lithothamnion glaciale (contemporary free-living, contemporary encrusting and sub-fossil free-living) and Phymatolithon calcareum (contemporary free-living) coralline algae. Mg is deposited within the calcite lattice in all seasons ( L. glaciale & P. calcareum) and thallus areas ( P. calcareum). These results suggest L. glaciale and P. calcareum are robust Mg-palaeotemperature proxies. We suggest that similar confirmation be obtained for Mg associations in other species of red coralline algae aiding our understanding of their role in climate reconstruction at large spatial scales.

  10. The dependence of Raman scattering on Mg concentration in Mg-doped GaN grown by MBE

    International Nuclear Information System (INIS)

    Flynn, Chris; Lee, William

    2014-01-01

    Magnesium-doped GaN (GaN:Mg) films having Mg concentrations in the range 5 × 10 18 –5 × 10 20 cm −3 were fabricated by molecular beam epitaxy. Raman spectroscopy was employed to study the effects of Mg incorporation on the positions of the E 2 and A 1 (LO) lines identifiable in the Raman spectra. For Mg concentrations in excess of 2 × 10 19 cm −3 , increases in the Mg concentration shift both lines to higher wave numbers. The shifts of the Raman lines reveal a trend towards compressive stress induced by incorporation of Mg into the GaN films. The observed correlation between the Mg concentration and the Raman line positions establish Raman spectroscopy as a useful tool for optimizing growth of Mg-doped GaN. (papers)

  11. Structural and electronic properties of Mg and Mg-Nb co-doped TiO2 (101) anatase surface

    International Nuclear Information System (INIS)

    Sasani, Alireza; Baktash, Ardeshir; Mirabbaszadeh, Kavoos; Khoshnevisan, Bahram

    2016-01-01

    Highlights: • Formation energy of Mg and Mg-Nb co-doped TiO_2 anatase surface (101) is studied. • Effect of Mg defect to the TiO_2 anatase (101) surface and bond length distribution of the surface is studied and it is shown that Mg defects tend to stay far from each other. • Effect of Mg and Nb to the bond length distribution of the surface studied and it is shown that these defects tend to stay close to each other. • Effects of Mg and Mg-Nb defects on DSSCs using TiO_2 anatase hosting these defects are studied. - Abstract: In this paper, by using density functional theory, Mg and Nb-Mg co-doping of TiO_2 anatase (101) surfaces are studied. By studying the formation energy of the defects and the bond length distribution of the surface, it is shown that Mg defects tend to stay as far as possible to induce least possible lattice distortion while Nb and Mg defects stay close to each other to cause less stress to the surface. By investigating band structure of the surface and changes stemmed from the defects, potential effects of Mg and Mg-Nb co-doping of TiO_2 surface on dye-sensitized solar cells are investigated. In this study, it is shown that the Nb-Mg co-doping could increase J_S_C of the surface while slightly decreasing V_O_C compared to Mg doped surface, which might result in an increase in efficiency of the DSSCs compared to Nb or Mg doped surfaces.

  12. Structural and electronic properties of Mg and Mg-Nb co-doped TiO2 (101) anatase surface

    Energy Technology Data Exchange (ETDEWEB)

    Sasani, Alireza [Department of Science, Karaj Islamic Azad University, Karaj, Alborz, P.O. Box 31485-313 (Iran, Islamic Republic of); Baktash, Ardeshir [Institute of Nano Science and Nano Technology, University of Kashan, Kashan, P.O. Box 87317-51167 (Iran, Islamic Republic of); Mirabbaszadeh, Kavoos, E-mail: mirabbas@aut.ac.ir [Department of Energy Engineering and Physics, Amirkabir University of Technology, Tehran, P. O. Box 15875-4413 (Iran, Islamic Republic of); Khoshnevisan, Bahram [Institute of Nano Science and Nano Technology, University of Kashan, Kashan, P.O. Box 87317-51167 (Iran, Islamic Republic of)

    2016-10-30

    Highlights: • Formation energy of Mg and Mg-Nb co-doped TiO{sub 2} anatase surface (101) is studied. • Effect of Mg defect to the TiO{sub 2} anatase (101) surface and bond length distribution of the surface is studied and it is shown that Mg defects tend to stay far from each other. • Effect of Mg and Nb to the bond length distribution of the surface studied and it is shown that these defects tend to stay close to each other. • Effects of Mg and Mg-Nb defects on DSSCs using TiO{sub 2} anatase hosting these defects are studied. - Abstract: In this paper, by using density functional theory, Mg and Nb-Mg co-doping of TiO{sub 2} anatase (101) surfaces are studied. By studying the formation energy of the defects and the bond length distribution of the surface, it is shown that Mg defects tend to stay as far as possible to induce least possible lattice distortion while Nb and Mg defects stay close to each other to cause less stress to the surface. By investigating band structure of the surface and changes stemmed from the defects, potential effects of Mg and Mg-Nb co-doping of TiO{sub 2} surface on dye-sensitized solar cells are investigated. In this study, it is shown that the Nb-Mg co-doping could increase J{sub SC} of the surface while slightly decreasing V{sub OC} compared to Mg doped surface, which might result in an increase in efficiency of the DSSCs compared to Nb or Mg doped surfaces.

  13. Constraints on the ^22Ne(α,n)^25Mg reaction rate from ^natMg+n Total and ^25Mg(n,γ ) Cross Sections

    Science.gov (United States)

    Koehler, Paul

    2002-10-01

    The ^22Ne(α,n)^25Mg reaction is the neutron source during the s process in massive and intermediate mass stars as well as a secondary neutron source during the s process in low mass stars. Therefore, an accurate determination of this rate is important for a better understanding of the origin of nuclides heavier than iron as well as for improving s-process models. Also, because the s process produces seed nuclides for a later p process in massive stars, an accurate value for this rate is important for a better understanding of the p process. Because the lowest observed resonance in direct ^22Ne(α,n)^25Mg measurements is considerably above the most important energy range for s-process temperatures, the uncertainty in this rate is dominated by the poorly known properties of states in ^26Mg between this resonance and threshold. Neutron measurements can observe these states with much better sensitivity and determine their parameters much more accurately than direct ^22Ne(α,n)^25Mg measurements. I have analyzed previously reported Mg+n total and ^25Mg(n,γ ) cross sections to obtain a much improved set of resonance parameters for states in ^26Mg in this region, and an improved estimate of the uncertainty in the ^22Ne(α,n)^25Mg reaction rate. This work was supported by the U.S. DOE under contract No. DE-AC05-00OR22725 with UT-Battell, LLC.

  14. Coherent interface structures and intergrain Josephson coupling in dense MgO/Mg{sub 2}Si/MgB{sub 2} nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Ueno, Katsuya; Takahashi, Kazuyuki; Uchino, Takashi, E-mail: uchino@kobe-u.ac.jp [Department of Chemistry, Graduate School of Science, Kobe University, Nada, Kobe 657-8501 (Japan); Nagashima, Yukihito [Nippon Sheet Glass Co., Ltd., Konoike, Itami 664-8520 (Japan); Seto, Yusuke [Department of Planetology, Graduate School of Science, Kobe University, Nada, Kobe 657-8501 (Japan); Matsumoto, Megumi; Sakurai, Takahiro [Center for Support to Research and Education Activities, Kobe University, Nada, Kobe 657-8501 (Japan); Ohta, Hitoshi [Molecular Photoscience Research Center, Kobe University, Nada, Kobe 657-8501 (Japan)

    2016-07-07

    Many efforts are under way to control the structure of heterointerfaces in nanostructured composite materials for designing functionality and engineering application. However, the fabrication of high-quality heterointerfaces is challenging because the crystal/crystal interface is usually the most defective part of the nanocomposite materials. In this work, we show that fully dense insulator (MgO)/semiconductor(Mg{sub 2}Si)/superconductor(MgB{sub 2}) nanocomposites with atomically smooth and continuous interfaces, including epitaxial-like MgO/Mg{sub 2}Si interfaces, are obtained by solid phase reaction between metallic magnesium and a borosilicate glass. The resulting nanocomposites exhibit a semiconductor-superconducting transition at 36 K owing to the MgB{sub 2} nanograins surrounded by the MgO/Mg{sub 2}Si matrix. This transition is followed by the intergrain phase-lock transition at ∼24 K due to the construction of Josephson-coupled network, eventually leading to a near-zero resistance state at 17 K. The method not only provides a simple process to fabricate dense nanocomposites with high-quality interfaces, but also enables to investigate the electric and magnetic properties of embedded superconducting nanograins with good intergrain coupling.

  15. Photoluminescence of Mg_2Si films fabricated by magnetron sputtering

    International Nuclear Information System (INIS)

    Liao, Yang-Fang; Xie, Quan; Xiao, Qing-Quan; Chen, Qian; Fan, Meng-Hui; Xie, Jing; Huang, Jin; Zhang, Jin-Min; Ma, Rui; Wang, Shan-Lan; Wu, Hong-Xian; Fang, Di

    2017-01-01

    Highlights: • High quality Mg_2Si films were grown on Si (111) and glass substrates with magnetron sputtering, respectively. • The first observation of Photoluminescence (PL) of Mg_2Si films was reported. • The Mg_2Si PL emission wavelengths are almost independence on temperature in the range of 77–300 K. • The strongest PL emissions may be attributed to interstitial Mg donor level to valence band transitions. • The activation energy of Mg_2Si is determined from the quenching of major luminescence peaks. - Abstract: To understand the photoluminescence mechanisms and optimize the design of Mg_2Si-based light-emitting devices, Mg_2Si films were fabricated on silicon (111) and glass substrates by magnetron sputtering technique, and the influences of different substrates on the photoelectric properties of Mg_2Si films were investigated systematically. The crystal structure, cross-sectional morphology, composition ratios and temperature-dependent photoluminescence (PL) of the Mg_2Si films were examined using X-ray diffraction (XRD), Scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDS) and PL measurement system, respectively. XRD results indicate that the Mg_2Si film on Si (111) displays polycrystalline structure, whereas Mg_2Si film on glass substrate is of like-monocrystalline structure.SEM results show that Mg_2Si film on glass substrate is very compact with a typical dense columnar structure, and the film on Si substrate represents slight delamination phenomenon. EDS results suggest that the stoichiometry of Mg and Si is approximately 2:1. Photoluminescence (PL) of Mg_2Si films was observed for the first time. The PL emission wavelengths of Mg_2Si are almost independence on temperature in the range of 77–300 K. The PL intensity decreases gradually with increasing temperature. The PL intensity of Mg_2Si films on glass substrate is much larger than that of Mg_2Si film on Si (111) substrate. The activation energy of 18 meV is

  16. Study of some Mg-based ferrites as humidity sensors

    International Nuclear Information System (INIS)

    Rezlescu, N; Rezlescu, E; Doroftei, C; Popa, P D

    2005-01-01

    The micostructure and humidity sensitivity of MgFe 2 O 4 + CaO, Mg 0.5 Cu 0.5 Fe 1.8 Ga 0.2 O 4 , Mg 0.5 Zn 0.5 Fe 2 O 4 + KCl and MgMn 0.2 Fe 1.8 O 4 ferrites were investigated. We have found that the humidity sensitivity largely depends on composition, crystallite size, surface area and porosity. The best results concerning humidity sensitivity were obtained for MgMn 0.2 Fe 1.8 O 4 ferrite

  17. Intrinsic Conductivity in Magnesium-Oxygen Battery Discharge Products: MgO and MgO2

    DEFF Research Database (Denmark)

    Smith, Jeffrey G.; Naruse, Junichi; Hiramatsu, Hidehiko

    2017-01-01

    Nonaqueous magnesium–oxygen (or “Mg-air”) batteries are attractive next generation energy storage devices due to their high theoretical energy densities, projected low cost, and potential for rechargeability. Prior experiments identified magnesium oxide, MgO, and magnesium peroxide, MgO2...

  18. A Computational Investigation of Precipitates in Mg-RE Alloys With Applications To Mg-X Systems

    Science.gov (United States)

    Issa, Ahmed

    Increasing fuel efficiency in transportation vehicles is a major policy goal for both government and auto and aerospace manufacturers. Lightweight structural materials, such as magnesium alloys, hold great promise in enabling such fuel efficiency gains. Understanding the controlling factors in Mg alloy strengthening is crucial for the rational design of structurally strong and inexpensive Mg alloys. In this work, we seek to understand the energetic underpinnings giving rise to a class of remarkably strong Mg alloys: Mg-RE systems. We use first-principles methods to efficiently explore seventeen Mg-RE systems, drawing out broad patterns and distilling our knowledge into simple design rules for Mg alloys. We begin by investigating the controlling factors for the Mg-strengthening prismatic plate precipitates in Mg-RE systems, discovering the critical role of strain in such systems. We then proceed to investigate the surprising role of interfacial energies in determining the course of the Mg-RE precipitation reactions. Using strain and interfacial energies, we construct a phase-field model which accurately depicts the precipitate morphology as a function of time and size in a Mg-Nd system. Finally, we combine our gained insights to implement a computational alloy design scheme on a large portion of the periodic table where we seek Mg-strengthening solutes. Our work advances the understanding of strengthening in Mg alloys and lays the groundwork for full scale computational alloy design.

  19. Enhanced post-annealing stability of perpendicular Ta/CoFeB/Mg/MgO multilayers by inhibiting Ta diffusion

    Energy Technology Data Exchange (ETDEWEB)

    Li, Xu-Jing; Jiang, Shao-Long; Zhang, Jing-Yan; Liu, Qian-Qian; Liu, Yi-Wei; Zhao, Jian-Cheng [Department of Materials Physics and Chemistry, University of Science and Technology Beijing, Beijing 100083 (China); Wu, Zheng-Long [Analytical and Testing Center, Beijing Normal University, Beijing 100875 (China); Feng, Chun, E-mail: fengchun@ustb.edu.cn [Department of Materials Physics and Chemistry, University of Science and Technology Beijing, Beijing 100083 (China); Li, Ming-Hua [Department of Materials Physics and Chemistry, University of Science and Technology Beijing, Beijing 100083 (China); Yu, Guang-Hua, E-mail: ghyu@mater.ustb.edu.cn [Department of Materials Physics and Chemistry, University of Science and Technology Beijing, Beijing 100083 (China)

    2016-03-01

    Graphical abstract: To reveal the underlying mechanism of Mg influence on the enhanced post-annealing stability of perpendicular Ta/CoFeB/Mg/MgO multilayers, the X-ray photoelectron spectroscopy analysis have been performed. It is found that a certain amount of Mg interlayer at the CoFeB/MgO interface could prevent the Ta oxidation to some extent due to the oxygen deficit MgO{sub x} (x < 1), and consequently lower the diffusion motivation of Ta from the bottom layer to the CoFeB/MgO interfaces to some extent during the annealing process. The prevention of Ta diffusion realizes the effective hybridization of Fe and O at the CoFeB/MgO interface and maintains interfacial magnetic anisotropy (K{sub CoFeB/MgO}). As a result, the perpendicular magnetic anisotropy at high annealing temperatures was maintained. - Highlights: • High annealing stability of perpendicular Ta/CoFeB/Mg/MgO multilayers was realized. • X-ray photoelectron spectroscopy analysis has been performed to explore the reasons. • The prevention of Ta diffusion was realized by introducing Mg at the CoFeB/MgO interface. - Abstracts: To reveal the underlying mechanism of Mg influence on the enhanced post-annealing stability of perpendicular Ta/CoFeB/Mg/MgO multilayers, the X-ray photoelectron spectroscopy analysis has been performed. It is found that a certain amount of Mg interlayer at the CoFeB/MgO interface could prevent the Ta oxidation, and consequently lower the diffusion motivation of Ta from the bottom layer to the CoFeB/MgO interfaces to some extent in the annealing process. The prevention of Ta diffusion realizes the effective hybridization of Fe and O at the CoFeB/MgO interface and maintains interfacial magnetic anisotropy (KCoFeB/MgO). As a result, the perpendicular magnetic anisotropy at high annealing temperatures is maintained.

  20. Single crystal structures of the new vanadates CuMgVO{sub 4} and AgMgVO{sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Ben Yahia, Hamdi, E-mail: Hyahia@qf.org.qa [Research Institute of Electrochemical Energy, National Institute of Advanced Industrial Science and Technology (AIST), 1-8-31 Midorigaoka, Ikeda, Osaka 563-8577 (Japan); Qatar Environment and Energy Research Institute, Hamad Bin Khalifa University, Qatar Foundation, PO Box 5825, Doha (Qatar); Shikano, Masahiro, E-mail: shikano.masahiro@aist.go.jp [Research Institute of Electrochemical Energy, National Institute of Advanced Industrial Science and Technology (AIST), 1-8-31 Midorigaoka, Ikeda, Osaka 563-8577 (Japan); Essehli, Rachid; Belharouak, Ilias [Qatar Environment and Energy Research Institute, Hamad Bin Khalifa University, Qatar Foundation, PO Box 5825, Doha (Qatar)

    2016-08-01

    The new compounds CuMgVO{sub 4} and AgMgVO{sub 4} have been synthesized by a solid state reaction route. Their crystal structures were determined from single-crystal X-ray diffraction data. CuMgVO{sub 4} crystallizes with Na{sub 2}CrO{sub 4}-type structure with space group Cmcm, a = 5.6932 (10), b = 8.7055 (15), c = 6.2789 (10) Å, V = 311.20 (9) Å{sup 3}, and Z = 4, whereas AgMgVO{sub 4} crystallizes in the maricite-type structure with space group Pnma, a = 9.4286 (14), b = 6.7465 (10), c = 5.3360 (8) Å, V = 339.42 (9) Å{sup 3}, and Z = 4. Both structures of CuMgVO{sub 4}, and AgMgVO{sub 4} contain MgO{sub 4} chains made up of edge-sharing MgO{sub 6} octahedra. In CuMgVO{sub 4} the MgO{sub 4} chains are interconnected through CuVO{sub 4} double chains made up of VO{sub 4} and CuO{sub 4} tetrahedra sharing corners and edges, however in AgMgVO{sub 4} the chains are interlinked by the VO{sub 4} and AgO{sub 4} tetrahedra sharing only corners. - Highlights: • We have been able to grow CuMgVO{sub 4} and AgMgVO{sub 4} single crystals. • We solved their crystal structures using single crystal data. • We compared the crystal structures of CuMgVO{sub 4} and AgMgVO{sub 4}.

  1. Enhanced post-annealing stability of perpendicular Ta/CoFeB/Mg/MgO multilayers by inhibiting Ta diffusion

    International Nuclear Information System (INIS)

    Li, Xu-Jing; Jiang, Shao-Long; Zhang, Jing-Yan; Liu, Qian-Qian; Liu, Yi-Wei; Zhao, Jian-Cheng; Wu, Zheng-Long; Feng, Chun; Li, Ming-Hua; Yu, Guang-Hua

    2016-01-01

    Graphical abstract: To reveal the underlying mechanism of Mg influence on the enhanced post-annealing stability of perpendicular Ta/CoFeB/Mg/MgO multilayers, the X-ray photoelectron spectroscopy analysis have been performed. It is found that a certain amount of Mg interlayer at the CoFeB/MgO interface could prevent the Ta oxidation to some extent due to the oxygen deficit MgO_x (x < 1), and consequently lower the diffusion motivation of Ta from the bottom layer to the CoFeB/MgO interfaces to some extent during the annealing process. The prevention of Ta diffusion realizes the effective hybridization of Fe and O at the CoFeB/MgO interface and maintains interfacial magnetic anisotropy (K_C_o_F_e_B_/_M_g_O). As a result, the perpendicular magnetic anisotropy at high annealing temperatures was maintained. - Highlights: • High annealing stability of perpendicular Ta/CoFeB/Mg/MgO multilayers was realized. • X-ray photoelectron spectroscopy analysis has been performed to explore the reasons. • The prevention of Ta diffusion was realized by introducing Mg at the CoFeB/MgO interface. - Abstracts: To reveal the underlying mechanism of Mg influence on the enhanced post-annealing stability of perpendicular Ta/CoFeB/Mg/MgO multilayers, the X-ray photoelectron spectroscopy analysis has been performed. It is found that a certain amount of Mg interlayer at the CoFeB/MgO interface could prevent the Ta oxidation, and consequently lower the diffusion motivation of Ta from the bottom layer to the CoFeB/MgO interfaces to some extent in the annealing process. The prevention of Ta diffusion realizes the effective hybridization of Fe and O at the CoFeB/MgO interface and maintains interfacial magnetic anisotropy (KCoFeB/MgO). As a result, the perpendicular magnetic anisotropy at high annealing temperatures is maintained

  2. Structural and optical properties of ZnMgO nanostructures formed by Mg in-diffused ZnO nanowires

    International Nuclear Information System (INIS)

    Pan, C.-J.; Hsu, H.-C.; Cheng, H.-M.; Wu, C.-Y.; Hsieh, W.-F.

    2007-01-01

    ZnMgO nanostructures with wurtzite phase were prepared by thermal diffusion of Mg into the ZnO nanowires. As ZnO light-emitting devices have been operated by using ZnMgO layers as energy barrier layers to confine the carriers, it is essential to realize the characterization of ZnMgO particularly. In this work, the Mg content in Zn 1 -x Mg x O alloy determined by X-ray diffraction (XRD) and photoluminescence (PL) shows a good coincidence. The variation of lattice constant and the blueshift of near-band-edge emission indicate that Zn 2+ ions are successfully substituted by Mg 2+ ions in the ZnO lattice. In Raman-scattering studies, the change of E 2 (high) phonon line shape in ZnO:Mg nanostructures reveals the microscopic substitutional disorder. In addition to the host phonons of ZnO, two additional bands around 383 and 510 cm -1 are presumably attributed to the Mg-related vibrational modes. - Graphical abstract: We reported the synthesis of the ZnMgO nanostructures prepared by a simple vapor transport method. Magnesium-related anomalous modes are observed by Raman spectra for the first time in ZnMgO system

  3. From $^{27}$Mg to ${33}$Mg transition to the "Island of inversion"

    CERN Document Server

    Yordanov, Deyan

    Since introduced in nuclear physics, the concept of shell structure and magic numbers has governed our understanding of nuclear matter in atomic nuclei close to stability. Nuclear species with a magic number of protons and/or neutrons are known to be more stable and close to spherical in shape. Experimental studies of 30Ne, 31Na and 32Mg, systems with a closed neutron sd shell (N=20), provide evidence for a ground-state deformation in these nuclei. The observed phenomenon is understood as an inversion of the normal spherical ground-state configuration, expected according to the traditional shell model, with deformed states governed by particle-hole excitations over the N=20 shell gap. The properties of nuclei in this Island of inversion are of particular importance for the theoretical modeling of the region. The present doctoral dissertation reports on the first determination of the nuclear ground-state spins and magnetic moments of 31,33Mg, obtained by means of laser spectroscopy in combination with nuclear...

  4. Mg concentration profile and its control in the low temperature grown Mg-doped GaN epilayer

    Science.gov (United States)

    Liu, S. T.; Yang, J.; Zhao, D. G.; Jiang, D. S.; Liang, F.; Chen, P.; Zhu, J. J.; Liu, Z. S.; Liu, W.; Xing, Y.; Zhang, L. Q.; Wang, W. J.; Li, M.; Zhang, Y. T.; Du, G. T.

    2018-01-01

    In this work, the Cp2Mg flux and growth pressure influence to Mg doping concentration and depth profiles is studied. From the SIMS measurement we found that a transition layer exists at the bottom region of the layer in which the Mg doping concentration changes gradually. The thickness of transition layer decreases with the increases of Mg doping concentration. Through analysis, we found that this is caused by Ga memory effect which the Ga atoms stay residual in MOCVD system will react with Mg source, leading a transition layer formation and improve the growth rate. And the Ga memory effect can be well suppressed by increasing Mg doping concentration and growth pressure and thus get a steep Mg doping at the bottom region of p type layer.

  5. Industrial production of MgH2 and its application

    International Nuclear Information System (INIS)

    Uesugi, H.; Sugiyama, T.; Nii, H.; Ito, T.; Nakatsugawa, I.

    2011-01-01

    Research highlights: → Tablet and powder Mg were hydrogenated in a 50 kg batch furnace based on thermal equilibrium method. → Compression of Mg tablet improved the hydrogenation yield. → Hydrolysis of MgH 2 using citric acid generated hydrogen under 373 K. → A MgH 2 -hydrogen reactor utilizing hydraulic head pressure was developed. → - Abstract: A process for the industrial production of magnesium hydride (MgH 2 ) based on a thermal equilibrium method and its application to portable hydrogen sources is proposed. Mg powders and tablets compressed with mechanically ground Mg ribbons were successfully hydrogenated in a 50-kg-batch furnace. The resultant MgH 2 showed a hydrogen yield of around 96% with good reproducibility. The compression ratio of Mg tablets was found to be an important factor in the hydrogenation yield. A hydrolysis technique using citric acid as an additive was employed to generate hydrogen under 373 K. Increasing the concentration of citric acid and the temperature accelerated the hydrolysis reactivity. A hydrogen reactor utilizing hydraulic head pressure was developed. It generated hydrogen continuously for 1 h at a flow rate of 100 ml min -1 with hydrolysis of 5 g of tablet-form MgH 2 . The conversion yield was around 70%, regardless of the flow rate.

  6. Corrosion behavior of Mg/graphene composite in aqueous electrolyte

    International Nuclear Information System (INIS)

    Selvam, M.; Saminathan, K.; Siva, P.; Saha, P.; Rajendran, V.

    2016-01-01

    In the present work, the electrochemical corrosion behavior of magnesium (Mg) and thin layer graphene coated Mg (Mg/graphene) are studied in different salt electrolyte such as NaCl, KCl and Na_2SO_4. The phase structure, crystallinity, and surface morphology of the samples are investigated using X-ray diffraction (XRD) analysis, scanning electron microscopy coupled with energy dispersive X-ray analysis (SEM/EDAX), and Raman spectroscopy techniques. The electrochemical corrosion behavior of the Mg and graphene coated Mg are also investigated using Electrochemical Impedance Spectroscopy (EIS) analysis. The tafel plot reveals that the corrosion of Mg drastically drops when coated with thin layer graphene (Mg/graphene) compared to Mg in KCl electrolyte. Moreover, the EIS confirms that Mg/graphene sample shows improve corrosion resistance and lower corrosion rate in KCl solution compare to all other electrolytes studied in the present system. - Highlights: • The corrosion behavior of magnesium alloy (AZ91) was investigated in three different electrolyte solution. • To study the anti-corrosion behavior of graphene coated with magnesium alloy. • To improve the corrosion resistance for magnesium alloy. • Nyquist plots confirms that MgG shows better corrosion resistance and lower corrosion rate in KCl solution.

  7. Corrosion behavior of Mg/graphene composite in aqueous electrolyte

    Energy Technology Data Exchange (ETDEWEB)

    Selvam, M. [Centre for Nano Science and Technology, KS Rangasamy College of Technology, Tiruchengode, 637215, Tamil Nadu (India); Saminathan, K., E-mail: ksaminath@gmail.com [Centre for Nano Science and Technology, KS Rangasamy College of Technology, Tiruchengode, 637215, Tamil Nadu (India); Siva, P. [Centre for Nano Science and Technology, KS Rangasamy College of Technology, Tiruchengode, 637215, Tamil Nadu (India); Saha, P. [Department of Ceramic Engineering, National Institute of Technology, Rourkela, India-769008 (India); Rajendran, V. [Centre for Nano Science and Technology, KS Rangasamy College of Technology, Tiruchengode, 637215, Tamil Nadu (India)

    2016-04-01

    In the present work, the electrochemical corrosion behavior of magnesium (Mg) and thin layer graphene coated Mg (Mg/graphene) are studied in different salt electrolyte such as NaCl, KCl and Na{sub 2}SO{sub 4}. The phase structure, crystallinity, and surface morphology of the samples are investigated using X-ray diffraction (XRD) analysis, scanning electron microscopy coupled with energy dispersive X-ray analysis (SEM/EDAX), and Raman spectroscopy techniques. The electrochemical corrosion behavior of the Mg and graphene coated Mg are also investigated using Electrochemical Impedance Spectroscopy (EIS) analysis. The tafel plot reveals that the corrosion of Mg drastically drops when coated with thin layer graphene (Mg/graphene) compared to Mg in KCl electrolyte. Moreover, the EIS confirms that Mg/graphene sample shows improve corrosion resistance and lower corrosion rate in KCl solution compare to all other electrolytes studied in the present system. - Highlights: • The corrosion behavior of magnesium alloy (AZ91) was investigated in three different electrolyte solution. • To study the anti-corrosion behavior of graphene coated with magnesium alloy. • To improve the corrosion resistance for magnesium alloy. • Nyquist plots confirms that MgG shows better corrosion resistance and lower corrosion rate in KCl solution.

  8. Low-energy radioactive ion beam production of 22Mg

    International Nuclear Information System (INIS)

    Duy, N.N.; Kubono, S.; Yamaguchi, H.; Kahl, D.; Wakabayashi, Y.; Teranishi, T.; Iwasa, N.; Kwon, Y.K.; Khiem, L.H.; Kim, Y.H.; Song, J.S.; Hu, J.; Ayyad, Y.

    2013-01-01

    The 22 Mg nucleus plays an important role in nuclear astrophysics, specially in the 22 Mg(α,p) 25 Al and proton capture 22 Mg(p,γ) 23 Al reactions. It is believed that 22 Mg is a waiting point in the αp-process of nucleosynthesis in novae. We proposed a direct measurement of the 22 Mg+α resonance reaction in inverse kinematics using a radioactive ion (RI) beam. A 22 Mg beam of 3.73 MeV/u was produced at CRIB (Center for Nuclear Study (CNS) low-energy RI Beam) facility of the University of Tokyo located at RIKEN (Japan) in 2011. In this paper we present the results about the production of the 22 Mg beam used for the direct measurement of the scattering reaction 22 Mg(α,α) 22 Mg, and the stellar reaction 22 Mg(α,p) 25 Al in the energy region concerning an astrophysical temperature of T 9 =1–3 GK

  9. The structural, electrical and optical properties of Mg-doped ZnO with different interstitial Mg concentration

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Yonghong, E-mail: hchyh@njust.edu.cn [School of Nuclear Technology and Chemistry & Biology, Hubei University of Science and Technology, Xianning 437100 (China); Institute of Optoelectronics & Nanomaterials, College of Materials Science and Engineering, Nanjing University of Science and Technology, Nanjing 210094 (China); Zeng, Haibo [Institute of Optoelectronics & Nanomaterials, College of Materials Science and Engineering, Nanjing University of Science and Technology, Nanjing 210094 (China); Du, Jifu [School of Nuclear Technology and Chemistry & Biology, Hubei University of Science and Technology, Xianning 437100 (China); Hu, Ziyu [Beijing Computational Science Research Center, Beijing 100084 (China); Zhang, Shengli [Institute of Optoelectronics & Nanomaterials, College of Materials Science and Engineering, Nanjing University of Science and Technology, Nanjing 210094 (China)

    2016-10-01

    Through first principle calculations, we studied the structural, electronic and optical properties of ZnO doped by interstitial Mg. With the increase of Mg content (x), the derivations of lattice parameters from the wurtzite ZnO become more and more significant. The Mg-doped ZnO with x below 15.79% is found to be n-type semiconductor. The minimum of energy band gap and light transmittance in high energy region (7.5–25 eV) decrease while the conductivity and refractive index increase with increasing x. Further increasing x up to 20%, the Mg-doped ZnO is found to be direct-band-gap semiconductor with great structural derivation from wurtzite phase. The light transmittance increases while the refractive index decreases with the increase of x due to the change of geometry and electronic structure. So, it’s concluded that the electronic and optical properties of ZnO doped by interstitial Mg may be greatly influenced by Mg content. - Graphical abstract: The minimum of energy gap decreases while the corresponding relative number of electrons into the conduction bands increases when the interstitial Mg content x in Mg-doped ZnO increases (0 ≤ x ≤ 15.79%). - Highlights: • The energy band gap decreases with the increase of interstitial Mg content from 5.88% to 15.79%. • The conductivity increases with the increase of interstitial Mg content from 5.88% to 15.79%. • The Mg{sub x}Zn{sub 1-x}O (interstitial Mg content x= 20%) is found to be a direct-band-gap semiconductor. • The light transmittance decreases with the increase of interstitial Mg content from 5.88% to 15.79%. • The refractive index increases with the increase of interstitial Mg content from 5.88% to 15.79%.

  10. Adsorption of arginine, glycine and aspartic acid on Mg and Mg-based alloy surfaces: A first-principles study

    Science.gov (United States)

    Fang, Zhe; Wang, Jianfeng; Yang, Xiaofan; Sun, Qiang; Jia, Yu; Liu, Hairong; Xi, Tingfei; Guan, Shaokang

    2017-07-01

    Studying the adsorption behaviors of biomolecules on the surface of Mg and Mg-based alloy has a fundamental and important role for related applications in biotechnology. In the present work, we systematically investigate and compare the adsorption properties of three typical amino acids, i.e., Arg (arginine), Gly (glycine) and Asp (aspartic acid), which form RGD tripeptide, on the Mg (0 0 0 1) surface with various doping (Zn, Y, and Nd), and aim to realize proper binding between biomolecules and Mg and Mg-based biomedical materials. Our results show that flat adsorption configurations of the functional groups binding to the surfaces are favored in energy for all the three selected amino acids. In specific, for the amino acids adsorped on clean Mg (0 0 0 1) surface, the adsorption energy (Eads) of Arg is found to be -1.67 eV for the most stable configuration, with amino and guanidyl groups binding with the surface. However, Gly (Asp) is found to binding with the surface through amino and carboxyl groups, with a -1.16 eV (-1.15 eV) binding energy. On the 2% Zn doped Mg (0 0 0 1) alloy surface (Mg-Zn (2%)), the Eads are significantly increased to be -1.91 eV, -1.32 eV and -1.35 eV for Arg, Gly and Asp, respectively. While the Mg-Y (1%) and Mg-Nd (1%) slightly weaken the adsorption of three amino acids. Moreover, we have performed detail discussions of the binding properties between amino acids and surfaces by projected density of states (PDOS) combined with charge transfer analyses. Our studies provide a comprehensive understanding on the interactions between amino acids and Mg and Mg-based alloy surfaces, with respect to facilitate the applications of Mg and Mg-based biomedical alloys in biosensing, drug delivery, biomolecule coating and other fields in biotechnology.

  11. Corrosion properties of the Mg alloy coated with polypyrrole films

    International Nuclear Information System (INIS)

    Grubač, Zoran; Rončević, Ivana Škugor; Metikoš-Huković, Mirjana

    2016-01-01

    Highlights: • Electropolymerization of pyrrole on Mg-alloy surface in presence of salicylate. • Salicylate dual role in PPy deposition: passivation and electron transfer mediation. • Redox potential of salicylate corresponds to potential of PPy nucleation. • EIS and polarization corrosion studies of PPy coated Mg-alloy in Hanks’ solution. • Polypyrrole significantly slowdown Mg alloy corrosion in Hanks’ solution. - Abstract: In the present study the reactive surface of Mg alloy was coated with the nontoxic biocompatible polypyrrole (PPy) film synthesized by electrochemical oxidation from an aqueous salicylate solution. Salicylate ions prevent Mg dissolution and act as an electron transfer mediator during the PPy film nucleation, formation and growth on the alloy surface. Kinetics of the pyrrole polymerization as well as corrosion resistance of the PPy coated Mg alloy in the Hanks’ solution were investigated using dc electrochemical methods and electrochemical impedance spectroscopy (EIS). Characterization of the surface film was performed by optical and Fourier transform infrared spectroscopy (FTIR).

  12. Thermoelectric properties and microstructure of Mg3Sb2

    International Nuclear Information System (INIS)

    Condron, Cathie L.; Kauzlarich, Susan M.; Gascoin, Franck; Snyder, G. Jeffrey

    2006-01-01

    Mg 3 Sb 2 has been prepared by direct reaction of the elements. Powder X-ray diffraction, thermal gravimetric, differential scanning calorimetery, and microprobe data were obtained on hot pressed samples. Single phase samples of Mg 3 Sb 2 were prepared and found to contain oxygen at the grain boundaries and to lose Mg and oxidize at temperatures above 900 K. Thermoelectric properties were characterized by Seebeck, electrical resistivity, and thermal conductivity measurements from 300 to 1023 K, and the maximum zT was found to be 0.21 at ∼875 K. - Graphical abstract: Dimensionless figure of merit for Mg 3 Sb 2 hot pressed and sintered at 873 K. The inset illustrates the crystal structure of Mg 3 Sb 2 along the [100] direction (white=Mg, black=Sb)

  13. A high resolution atlas of Mg II profiles

    Science.gov (United States)

    Ewald, R.; Nichols-Bohlin, Joy Y.; Kondo, Yoji

    1990-01-01

    An atlas of high dispersion Mg II profiles for standard stars of spectral types B0 through G9 is presented. The atlas contains plots of the Mg II profiles for approximately 65 stars and associated equivalent width measurements for both absorption and emission components, and the subordinate lines. The atlas is used to investigate systematic behavior of the Mg II profiles and correlation of the behavior with spectral classification.

  14. MgO nanoparticles as antibacterial agent: preparation and activity

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Zhen-Xing, E-mail: tangzhenxing@126.com [Department of Food Science, Anqing, Vocational and Technical College, Anqing, Anhui (China); Lv, Bin-Feng [Date Palm Research Center, King Faisal University, (Saudi Arabia)

    2014-07-15

    Bacterial pollution is a great risk for human health. Nanotechnology offers a way to develop new inorganic antibacterial agents. Nano-inorganic metal oxide has a potential to reduce bacterial contamination. MgO is an important inorganic oxide and has been widely used in many fields. Many studies have shown that MgO nanoparticles have good antibacterial activity. Therefore, in this paper, the main synthesis methods, antibacterial activity and antibacterial mechanisms of MgO nanoparticles are reviewed. (author)

  15. MgO nanoparticles as antibacterial agent: preparation and activity

    International Nuclear Information System (INIS)

    Tang, Zhen-Xing; Lv, Bin-Feng

    2014-01-01

    Bacterial pollution is a great risk for human health. Nanotechnology offers a way to develop new inorganic antibacterial agents. Nano-inorganic metal oxide has a potential to reduce bacterial contamination. MgO is an important inorganic oxide and has been widely used in many fields. Many studies have shown that MgO nanoparticles have good antibacterial activity. Therefore, in this paper, the main synthesis methods, antibacterial activity and antibacterial mechanisms of MgO nanoparticles are reviewed. (author)

  16. Effect of amorphous Mg50Ni50 on hydriding and dehydriding behavior of Mg2Ni alloy

    International Nuclear Information System (INIS)

    Guzman, D.; Ordonez, S.; Fernandez, J.F.; Sanchez, C.; Serafini, D.; Rojas, P.A.; Aguilar, C.; Tapia, P.

    2011-01-01

    Composite Mg 2 Ni (25 wt.%) amorphous Mg 50 Ni 50 was prepared by mechanical milling starting with nanocrystalline Mg 2 Ni and amorphous Mg 50 Ni 50 powders, by using a SPEX 8000 D mill. The morphological and microstructural characterization of the powders was performed via scanning electron microscopy and X-ray diffraction. The hydriding characterization of the composite was performed via a solid gas reaction method in a Sievert's-type apparatus at 363 K under an initial hydrogen pressure of 2 MPa. The dehydriding behavior was studied by differential thermogravimetry. On the basis of the results, it is possible to conclude that amorphous Mg 50 Ni 50 improved the hydriding and dehydriding kinetics of Mg 2 Ni alloy upon cycling. A tentative rationalization of experimental observations is proposed. - Research Highlights: → First study of the hydriding behavior of composite Mg 2 Ni (25 wt.%) amorphous Mg 50 Ni 50 . → Microstructural characterization of composite material using XRD and SEM was obtained. → An improved effect of Mg 50 Ni 50 on the Mg 2 Ni hydriding behavior was verified. → The apparent activation energy for the hydrogen desorption of composite was obtained.

  17. Lattice stability and formation energies of intrinsic defects in Mg2Si and Mg2Ge via first principles simulations

    International Nuclear Information System (INIS)

    Jund, Philippe; Viennois, Romain; Tédenac, Jean-Claude; Colinet, Catherine; Hug, Gilles; Fèvre, Mathieu

    2013-01-01

    We report an ab initio study of the semiconducting Mg 2 X (with X = Si, Ge) compounds and in particular we analyze the formation energies of the different point defects with the aim of understanding the intrinsic doping mechanisms. We find that the formation energy of Mg 2 Ge is 50% larger than that of Mg 2 Si, in agreement with the experimental tendency. From a study of the stability and the electronic properties of the most stable defects, taking into account the growth conditions, we show that the main cause of the n doping in these materials comes from interstitial magnesium defects. Conversely, since other defects acting like acceptors such as Mg vacancies or multivacancies are more stable in Mg 2 Ge than in Mg 2 Si, this explains why Mg 2 Ge can be of n or p type, in contrast to Mg 2 Si. The finding that the most stable defects are different in Mg 2 Si and Mg 2 Ge and depend on the growth conditions is important and must be taken into account in the search for the optimal doping to improve the thermoelectric properties of these materials.

  18. Hydrodechlorination of Tetrachloromethane over Palladium Catalysts Supported on Mixed MgF2-MgO Carriers

    Directory of Open Access Journals (Sweden)

    Magdalena Bonarowska

    2016-11-01

    Full Text Available Pd/MgO, Pd/MgF2 and Pd/MgO-MgF2 catalysts were investigated in the reaction of CCl4 hydrodechlorination. All the catalysts deactivated in time on stream, but the degree of deactivation varied from catalyst to catalyst. The MgF2-supported palladium with relatively large metal particles appeared the best catalyst, characterized by good activity and selectivity to C2-C5 hydrocarbons. Investigation of post-reaction catalyst samples allowed to find several details associated with the working state of hydrodechlorination catalysts. The role of support acidity was quite complex. On the one hand, a definite, although not very high Lewis acidity of MgF2 is beneficial for shaping high activity of palladium catalysts. The MgO-MgF2 support characterized by stronger Lewis acidity than MgF2 contributes to very good catalytic activity for a relatively long reaction period (~5 h but subsequent neutralization of stronger acid centers (by coking eliminates them from the catalyst. On the other hand, the role of acidity evolution, which takes place when basic supports (like MgO are chlorided during HdCl reactions, is difficult to assess because different events associated with distribution of chlorided support species, leading to partial or even full blocking of the surface of palladium, which plays the role of active component in HdCl reactions.

  19. Enhanced voltage-controlled magnetic anisotropy in magnetic tunnel junctions with an MgO/PZT/MgO tunnel barrier

    Science.gov (United States)

    Chien, Diana; Li, Xiang; Wong, Kin; Zurbuchen, Mark A.; Robbennolt, Shauna; Yu, Guoqiang; Tolbert, Sarah; Kioussis, Nicholas; Khalili Amiri, Pedram; Wang, Kang L.; Chang, Jane P.

    2016-03-01

    Compared with current-controlled magnetization switching in a perpendicular magnetic tunnel junction (MTJ), electric field- or voltage-induced magnetization switching reduces the writing energy of the memory cell, which also results in increased memory density. In this work, an ultra-thin PZT film with high dielectric constant was integrated into the tunneling oxide layer to enhance the voltage-controlled magnetic anisotropy (VCMA) effect. The growth of MTJ stacks with an MgO/PZT/MgO tunnel barrier was performed using a combination of sputtering and atomic layer deposition techniques. The fabricated MTJs with the MgO/PZT/MgO barrier demonstrate a VCMA coefficient, which is ˜40% higher (19.8 ± 1.3 fJ/V m) than the control sample MTJs with an MgO barrier (14.3 ± 2.7 fJ/V m). The MTJs with the MgO/PZT/MgO barrier also possess a sizeable tunneling magnetoresistance (TMR) of more than 50% at room temperature, comparable to the control MTJs with an MgO barrier. The TMR and enhanced VCMA effect demonstrated simultaneously in this work make the MgO/PZT/MgO barrier-based MTJs potential candidates for future voltage-controlled, ultralow-power, and high-density magnetic random access memory devices.

  20. Comparing the Electrochemical Performance of LiFePO4/C Modified by Mg Doping and MgO Coating

    Directory of Open Access Journals (Sweden)

    Jianjun Song

    2013-01-01

    Full Text Available Supervalent cation doping and metal oxide coating are the most efficacious and popular methods to optimize the property of LiFePO4 lithium battery material. Mg-doped and MgO-coated LiFePO4/C were synthesized to analyze their individual influence on the electrochemical performance of active material. The specific capacity and rate capability of LiFePO4/C are improved by both MgO coating and Mg doping, especially the Mg-doped sample—Li0.985Mg0.015FePO4/C, whose discharge capacity is up to 163 mAh g−1, 145.5 mAh g−1, 128.3 mAh g−1, and 103.7 mAh g−1 at 1 C, 2 C, 5 C, and 10 C, respectively. The cyclic life of electrode is obviously increased by MgO surface modification, and the discharge capacity retention rate of sample LiFePO4/C-MgO2.5 is up to 104.2% after 100 cycles. Comparing samples modified by these two methods, Mg doping is more prominent on prompting the capacity and rate capability of LiFePO4, while MgO coating is superior in terms of improving cyclic performance.

  1. Effect of sterilization process on surface characteristics and biocompatibility of pure Mg and MgCa alloys

    International Nuclear Information System (INIS)

    Liu, X.L.; Zhou, W.R.; Wu, Y.H.; Cheng, Y.; Zheng, Y.F.

    2013-01-01

    The aim of this work was to investigate the effect of various sterilization methods on surface characteristics and biocompatibility of MgCa alloy, with pure Mg as a comparison, including steam autoclave sterilization (SA), ethylene oxide steam sterilization (EO), glutaraldehyde sterilization (GD), dry heat sterilization (DH) and Co60 γ ray radiation sterilization (R) technologies. The surface characterizations were performed by environmental scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, grazing incidence X-ray diffraction, water contact angle and surface free energy measurement, whereas the cytotoxicity and hemocompatibility were evaluated by cellular adhesive experiment, platelet adhesion and hemolysis test. The results showed that the five sterilization processes caused more changes on the surface of MgCa alloy than that on the surface of pure Mg. The GD sterilization caused the most obvious changes on the surface of the pure Mg, and the SA sterilization made the largest alteration on the MgCa alloy surface. The GD and DH sterilization processes could cause increases on surface free energy for both pure Mg and MgCa alloys, while the other three sterilization processes reduced the surface free energy. The DH and GD sterilization processes caused the least alteration on the cell adhesion on pure Mg surface, whereas the EO sterilization performed the greatest impact on the cell adhesion on the Mg–Ca alloy surface. The hemolysis percentage of pure Mg and MgCa alloys were reduced by SA sterilization, meanwhile the other four sterilization processes increased their hemolysis percentages significantly, especially for the EO sterilization. - Highlights: • The effect of sterilization on surface chemistry and biocompatibility was studied. • Sterilization caused more surface changes on MgCa alloy than pure Mg. • Co60 γ ray radiation is the most appropriate sterilization process

  2. Mg and Mg alloys: how comparable are in vitro and in vivo corrosion rates? A review.

    Science.gov (United States)

    Martinez Sanchez, Adela Helvia; Luthringer, Bérengère J C; Feyerabend, Frank; Willumeit, Regine

    2015-02-01

    Due to their biodegradability, magnesium and magnesium-based alloys could represent the third generation of biomaterials. However, their mechanical properties and time of degradation have to match the needs of applications. Several approaches, such as choice of alloying elements or tailored microstructure, are employed to tailor corrosion behaviour. Due to the high electrochemical activity of Mg, numerous environmental factors (e.g. temperature and surrounding ion composition) influence its corrosion behaviour, making it unpredictable. Nevertheless, the need of reliable in vitro model(s) to predict in vivo implant degradation is increasing. In an attempt to find a correlation between in vitro and vivo corrosion rates, this review presents a systematic literature survey, as well as an attempt to correlate the different results. Copyright © 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  3. Defect structure of ultrafine MgB2 nanoparticles

    International Nuclear Information System (INIS)

    Bateni, Ali; Somer, Mehmet; Repp, Sergej; Erdem, Emre; Thomann, Ralf; Acar, Selçuk

    2014-01-01

    Defect structure of MgB 2 bulk and ultrafine particles, synthesized by solid state reaction route, have been investigated mainly by the aid of X-band electron paramagnetic resonance spectrometer. Two different amorphous Boron (B) precursors were used for the synthesis of MgB 2 , namely, boron 95 (purity 95%–97%, <1.5 μm) and nanoboron (purity >98.5%, <250 nm), which revealed bulk and nanosized MgB 2 , respectively. Scanning and transmission electron microscopy analysis demonstrate uniform and ultrafine morphology for nanosized MgB 2 in comparison with bulk MgB 2 . Powder X-ray diffraction data show that the concentration of the by-product MgO is significantly reduced when nanoboron is employed as precursor. It is observed that a significant average particle size reduction for MgB 2 can be achieved only by using B particles of micron or nano size. The origin and the role of defect centers were also investigated and the results proved that at nanoscale MgB 2 material contains Mg vacancies. Such vacancies influence the connectivity and the conductivity properties which are crucial for the superconductivity applications

  4. Mechanism of magnetoresistance ratio enhancement in MgO/NiFe/MgO heterostructure by rapid thermal annealing

    Science.gov (United States)

    Zhao, Chong-Jun; Liu, Yang; Zhang, Jing-Yan; Sun, Li; Ding, Lei; Zhang, Peng; Wang, Bao-Yi; Cao, Xing-Zhong; Yu, Guang-Hua

    2012-08-01

    To reveal thermal effects on the film quality/microstructure evolution and the resulted magnetoresistance (MR) ratio in MgO/NiFe/MgO heterostructures, positron annihilation spectroscopy studies have been performed. It is found that the ionic interstitials in the MgO layers recombine with the nearby vacancies at lower annealing temperatures (200-300 °C) and lead to a slow increase in sample MR. Meanwhile, vacancy defects agglomeration/removal and ordering acceleration in MgO will occur at higher annealing temperatures (450-550 °C) and the improved MgO and MgO/NiFe interfaces microstructure are responsible for the observed significant MR enhancement.

  5. The in vitro biocompatibility and macrophage phagocytosis of Mg17Al12 phase in Mg-Al-Zn alloys.

    Science.gov (United States)

    Liu, Chen; He, Peng; Wan, Peng; Li, Mei; Wang, Kehong; Tan, Lili; Zhang, Yu; Yang, Ke

    2015-07-01

    Mg alloys are gaining interest for applications as biodegradable medical implant, including Mg-Al-Zn series alloys with good combination of mechanical properties and reasonable corrosion resistance. However, whether the existence of second phase particles in the alloys exerts influence on the biocompatibility is still not clear. A deeper understanding of how the particles regulate specific biological responses is becoming a crucial requirement for their subsequent biomedical application. In this work, the in vitro biocompatibility of Mg17Al12 as a common second phase in biodegradable Mg-Al-Zn alloys was investigated via hemolysis, cytotoxicity, cell proliferation, and cell adhesion tests. Moreover, osteogenic differentiation was evaluated by the extracellular matrix mineralization assay. The Mg17Al12 particles were also prepared to simulate the real situation of second phase in the in vivo environment in order to estimate the cellular response in macrophages to the Mg17Al12 particles. The experimental results indicated that no hemolysis was found and an excellent cytocompatibility was also proved for the Mg17Al12 second phase when co-cultured with L929 cells, MC3T3-E1 cells and BMSCs. Macrophage phagocytosis co-culture test revealed that Mg17Al12 particles exerted no harmful effect on RAW264.7 macrophages and could be phagocytized by the RAW264.7 cells. Furthermore, the possible inflammatory reaction and metabolic way for Mg17Al12 phase were also discussed in detail. © 2014 Wiley Periodicals, Inc.

  6. Bioequivalence of a single 400-mg dose of imatinib 100-mg oral tablets and a 400-mg tablet in healthy adult Korean volunteers.

    Science.gov (United States)

    Lee, Hae Won; Seong, Sook Jin; Park, Sung Min; Lee, Joomi; Gwon, Mi-Ri; Kim, Hyun-Ju; Lim, Sung Mook; Lim, Mi-Sun; Kim, Woomi; Yang, Dong Heon; Yoon, Young-Ran

    2015-06-01

    Imatinib mesylate (IM) is a selective tyrosine kinase inhibitor for the treatment of chronic myeloid leukemia and gastrointestinal stromal tumors. A new once-daily 400-mg film-coated tablet of imatinib has been developed by a pharmaceutical company in Korea. The present study was designed to assess and compare the PK parameters, bioavailability, and bioequivalence of the new imatinib 400-mg formulation (test) versus the conventional 100-mg formulation (reference) administered as a single 400-mg dose in healthy adult male volunteers. This randomized, open-label, single-dose, two-way crossover study was conducted in healthy Korean male volunteers. Eligible subjects were randomly assigned in a 1 : 1 ratio to receive 400 mg of the test (one 400-mg tablet) or reference (four 100-mg tablets) formulation, followed by a 2-week washout period and administration of the alternate formulation. Serial blood samples were collected at 0 (predose), 0.5, 1, 1.5, 2, 2.5, 3, 4, 6, 8, 10, 12, 24, 48, and 72 hours after administration. Plasma imatinib concentrations were determined using liquid chromatography coupled with tandem mass spectrometry. The formulations were to be considered bioequivalent if the 90% confidence intervals (CIs) of the adjusted geometric mean ratios for Cmax, AUC(0-t), and AUC(0-∞)ž were within the predetermined range of 0.80 - 1.25. In total, 35 subjects completed the study. No serious adverse event was reported during the study. The 90% CIs of the adjusted geometric mean ratios of the test formulation to the reference formulation for C(max), AUC(0-t) and AUC(0-∞)ž of imatinib were all within the bioequivalence criteria range of 0.8 - 1.25. The test formulation of imatinib met the Korean regulatory requirements for bioequivalence. Both imatinib formulations were well-tolerated in all subjects.

  7. Detection of Mg spinel lithologies on central peak of crater ...

    Indian Academy of Sciences (India)

    identified Fe bearing Mg-spinel-rich rock types are defined by their strong 2-μm ... The Modified Gaussian Modeling (MGM) analysis ... study the deep crustal and/or upper mantle composition and may lead to a fresh ... Lunar surface; Mg-spinel; central peak; Theophilus; remote sensing. .... The explanation of these spec-.

  8. Projectile deformation effects in the breakup of 37Mg

    Directory of Open Access Journals (Sweden)

    Shubhchintak

    2016-01-01

    Full Text Available We study the breakup of 37Mg on Pb at 244MeV/u with the recently developed extended theory of Coulomb breakup within the postform finite range distorted wave Born approximation that includes deformation of the projectile. Comparing our calculated cross section with the available Coulomb breakup data we determine the possible ground state configuration of 37Mg.

  9. Phosphorus Doped Zn 1- x Mg x O Nanowire Arrays

    KAUST Repository

    Lin, S. S.; Hong, J. I.; Song, J. H.; Zhu, Y.; He, H. P.; Xu, Z.; Wei, Y. G.; Ding, Y.; Snyder, R. L.; Wang, Z. L.

    2009-01-01

    We demonstrate the growth of phosphorus doped Zn 1-xMg xO nanowire (NW) using pulsed laser deposition. For the first time, p-type Zn 0.92Mg 0.08O:P NWs are likely obtained In reference to atomic force microscopy based piezoelectric output

  10. Structural and transport properties of Sn-Mg alloys

    International Nuclear Information System (INIS)

    Meydaneri, F.; Saatci, E.; Oezdemir, M.; Ari, M.; Durmus, S.

    2010-01-01

    The structural and temperature dependence transport of Sn-Mg alloys have been investigated for five different samples (Pure Sn, Sn-1.0 wt % Mg , Sn-2.0 wt % Mg , Sn-6.0 wt.% Mg and Pure Mg). Scanning Electron Microscopy (SEM), x-ray diffraction (XRD) and Energy Dispersive x-ray Analysis (EDX) measurements were carried out in order to clarify the structural properties of the samples. It has been found that, the samples have tetragonal crystal symmetry except the pure Mg which has hexagonal crystal symmetry. The cell parameters decrease slightly with addition of Mg element. The SEM micrographs of the samples show that, the samples have smooth surfaces with clear grain boundary. There is no crack, porosity or defects on the surfaces. The electrical resistivity of the samples increases almost linearly with the increasing temperature, which were measured by four-point probe technique. The thermal conductivity values are in between 0.60-1.00 W/Km, which are decrease slightly with temperature and increase with composition of Mg. The thermal conductivity values of the alloys are in between the values of the pure samples. Thermal conductivity results of the alloys have been compared with available other studies and a good agreement has been seen between the results. In addition, the temperature coefficients of electrical resistivity and thermal conductivity have been determined, which are independent with the compositions of alloying elements

  11. Stabilization of Reactive MgO Surfaces by Ni Doping

    Science.gov (United States)

    Mazheika, Aliaksei; Levchenko, Sergey V.

    Ni-MgO solid solutions are promising materials for catalytic reduction of CO2 and dry reforming of CH4. To explain the catalytic activity, an ab initio study of Ni-substitutional defects in MgO (NiMg) has been performed. At first, the validation of the theory level was done. We compared results of CCSD(T) embedded-cluster calculations of NiMg formation energies and adsorption energies of CO, CO2 and H2 on them to the HSE(α) hybrid DFT functional with the fraction of the exact exchange α varied between 0 and 1. HSE(0.3) was found to be the best compromise in this study. Our periodic HSE(0.3) calculations show that NiMg defects are most stable at corner sites, followed by steps, and are least stable at (001) terraces. Thus, Ni-doping stabilizes stepped MgO surfaces. The dissociative adsorption of H2 on the terrace is found to be endothermic (+ 1 . 1 eV), whereas on (110) surface with NiMg it is highly exothermic (- 1 . 6 eV). Adsorbed CO2 is also significantly stabilized (- 0 . 6 vs. - 2 . 2 eV). These findings explain recent microcalorimetry measurements of H2 and CO2 adsorption at doped Ni-MgO samples. partially supported by UniCat (Deutsche Forschungsgemeinschaft).

  12. Sorption of malachite green (MG) by cassava stem biochar (CSB ...

    African Journals Online (AJOL)

    Cassava stem biochar (CSB) was produced by pyrolyzing CS at 500°C for 2 hours at nitrogen environment. Proximate and ultimate analyses were conducted on CS and CSB. Batch sorption experiment on synthetic MG wastewater was optimized for the sorbent dosage, MG solution pH and contact time. Sorption data was ...

  13. Strength and residual stress of Mg-PSZ after grinding

    NARCIS (Netherlands)

    van den Berg, P.H.J.; With, de G.

    1993-01-01

    The influence of grinding with two grinding wheels, differing mainly in diamond-grain size, on the properties of MgO-partially stabilized ZrO2 ceramics (Mg-PSZ) was examd. The residual stress, the amt. of monoclinic zirconia, and the strength of the material were detd. From these measurements, depth

  14. Search for C+ C clustering in Mg ground state

    Indian Academy of Sciences (India)

    2017-01-04

    Jan 4, 2017 ... Finite-range knockout theory predictions were much larger for (12C,212C) reaction, indicating a very small 12C−12C clustering in 24Mg. (g.s.) . Our present results contradict most of the proposed heavy cluster (12C+12C) structure models for the ground state of 24Mg. Keywords. Direct nuclear reactions ...

  15. WIPP Magnesium Oxide (MgO) - Planned Change Request

    Science.gov (United States)

    On April 10, 2006, the DOE submitted a planned change request pertaining to the amount of MgO emplaced in the WIPP repository. MgO is an engineered barrier that DOE included as part of the original WIPP Certification Decision.

  16. Nanostructured Layered Cathode for Rechargeable Mg-Ion Batteries.

    Science.gov (United States)

    Tepavcevic, Sanja; Liu, Yuzi; Zhou, Dehua; Lai, Barry; Maser, Jorg; Zuo, Xiaobing; Chan, Henry; Král, Petr; Johnson, Christopher S; Stamenkovic, Vojislav; Markovic, Nenad M; Rajh, Tijana

    2015-08-25

    Nanostructured bilayered V2O5 was electrochemically deposited within a carbon nanofoam conductive support. As-prepared electrochemically synthesized bilayered V2O5 incorporates structural water and hydroxyl groups, which effectively stabilizes the interlayers and provides coordinative preference to the Mg(2+) cation in reversible cycling. This open-framework electrode shows reversible intercalation/deintercalation of Mg(2+) ions in common electrolytes such as acetonitrile. Using a scanning transmission electron microscope we demonstrate that Mg(2+) ions can be effectively intercalated into the interlayer spacing of nanostructured V2O5, enabling electrochemical magnesiation against a Mg anode with a specific capacity of 240 mAh/g. We employ HRTEM and X-ray fluorescence (XRF) imaging to understand the role of environment in the intercalation processes. A rebuilt full cell was tested by employing a high-energy ball-milled Sn alloy anode in acetonitrile with Mg(ClO4)2 salt. XRF microscopy reveals effective insertion of Mg ions throughout the V2O5 structure during discharge and removal of Mg ions during electrode charging, in agreement with the electrode capacity. We show using XANES and XRF microscopy that reversible Mg intercalation is limited by the anode capacity.

  17. Mechanical alloying and sitering of TI - 10WT.% MG powders

    CSIR Research Space (South Africa)

    Machio, Christopher N

    2009-06-01

    Full Text Available A Ti-10wt.%Mg powder alloy has been produced by mechanical alloying. Elemental powders of Ti and Mg were ball milled in a Zoz-Simoloyer CM01 for 16 and 20 hours under argon. Mechanical alloying was followed by XRD, SEM and particle size analysis...

  18. Selective antibacterial effects of mixed ZnMgO nanoparticles

    International Nuclear Information System (INIS)

    Vidic, Jasmina; Stankic, Slavica; Haque, Francia; Ciric, Danica; Le Goffic, Ronan; Vidy, Aurore; Jupille, Jacques; Delmas, Bernard

    2013-01-01

    Antibiotic resistance has impelled the research for new agents that can inhibit bacterial growth without showing cytotoxic effects on humans and other species. We describe the synthesis and physicochemical characterization of nanostructured ZnMgO whose antibacterial activity was compared to its pure nano-ZnO and nano-MgO counterparts. Among the three oxides, ZnO nanocrystals—with the length of tetrapod legs about 100 nm and the diameter about 10 nm—were found to be the most effective antibacterial agents since both Gram-positive (B. subtilis) and Gram-negative (E. coli) bacteria were completely eradicated at concentration of 1 mg/mL. MgO nanocubes (the mean cube size ∼50 nm) only partially inhibited bacterial growth, whereas ZnMgO nanoparticles (sizes corresponding to pure particles) revealed high specific antibacterial activity to Gram-positive bacteria at this concentration. Transmission electron microscopy analysis showed that B. subtilis cells were damaged after contact with nano-ZnMgO, causing cell contents to leak out. Our preliminary toxicological study pointed out that nano-ZnO is toxic when applied to human HeLa cells, while nano-MgO and the mixed oxide did not induce any cell damage. Overall, our results suggested that nanostructured ZnMgO, may reconcile efficient antibacterial efficiency while being a safe new therapeutic for bacterial infections.

  19. Revisiting Mg–Mg2Ni System from Electronic Perspective

    Directory of Open Access Journals (Sweden)

    Zhao Qian

    2017-11-01

    Full Text Available Both Mg and Mg2Ni are promising electrode materials in conversion-type secondary batteries. Earlier studies have shown their single-phase prospects in electro-devices, while in this work, we have quantitatively reported the electronic properties of their dual-phase materials, that is, Mg–Mg2Ni alloys, and analyzed the underlying reasons behind the property changes of materials. The hypoeutectic Mg–Mg2Ni alloys are found to be evidently more conductive than the hypereutectic Mg–Mg2Ni system. The density functional theory (DFT calculations give the intrinsic origin of electronic structures of both Mg2Ni and Mg. The morphology of quasi-nanoscale eutectics is another factor that can affect the electronic properties of the investigated alloy system; that is, the electrical property change of the investigated alloys system is due to a combination of the intrinsic property difference between the two constituting phases and the change of eutectic microstructures that affect electron scattering. In addition, regarding the Mg–Mg2Ni alloy design for device applications, the electronic property and mechanical aspect should be well balanced.

  20. Multiband model for tunneling in MgB2 junctions

    NARCIS (Netherlands)

    Brinkman, Alexander; Golubov, Alexandre Avraamovitch; Rogalla, Horst; Dolgov, O.V.; Kortus, J.; Kong, Y.; Jepsen, O.; Andersen, O.K.

    2002-01-01

    A theoretical model for quasiparticle and Josephson tunneling in multiband superconductors is developed and applied to MgB2-based junctions. The gap functions in different bands in MgB2 are obtained from an extended Eliashberg formalism, using the results of band structure calculations. The

  1. Selective antibacterial effects of mixed ZnMgO nanoparticles

    Science.gov (United States)

    Vidic, Jasmina; Stankic, Slavica; Haque, Francia; Ciric, Danica; Le Goffic, Ronan; Vidy, Aurore; Jupille, Jacques; Delmas, Bernard

    2013-05-01

    Antibiotic resistance has impelled the research for new agents that can inhibit bacterial growth without showing cytotoxic effects on humans and other species. We describe the synthesis and physicochemical characterization of nanostructured ZnMgO whose antibacterial activity was compared to its pure nano-ZnO and nano-MgO counterparts. Among the three oxides, ZnO nanocrystals—with the length of tetrapod legs about 100 nm and the diameter about 10 nm—were found to be the most effective antibacterial agents since both Gram-positive ( B. subtilis) and Gram-negative ( E. coli) bacteria were completely eradicated at concentration of 1 mg/mL. MgO nanocubes (the mean cube size 50 nm) only partially inhibited bacterial growth, whereas ZnMgO nanoparticles (sizes corresponding to pure particles) revealed high specific antibacterial activity to Gram-positive bacteria at this concentration. Transmission electron microscopy analysis showed that B. subtilis cells were damaged after contact with nano-ZnMgO, causing cell contents to leak out. Our preliminary toxicological study pointed out that nano-ZnO is toxic when applied to human HeLa cells, while nano-MgO and the mixed oxide did not induce any cell damage. Overall, our results suggested that nanostructured ZnMgO, may reconcile efficient antibacterial efficiency while being a safe new therapeutic for bacterial infections.

  2. Selective antibacterial effects of mixed ZnMgO nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Vidic, Jasmina, E-mail: jasmina.vidic@jouy.inra.fr [VIM, Institut de la Recherche Agronomique (France); Stankic, Slavica, E-mail: slavica.stankic@insp.jussieu.fr; Haque, Francia [CNRS, Institut des Nanosciences de Paris, UMR 7588 (France); Ciric, Danica; Le Goffic, Ronan; Vidy, Aurore [VIM, Institut de la Recherche Agronomique (France); Jupille, Jacques [CNRS, Institut des Nanosciences de Paris, UMR 7588 (France); Delmas, Bernard [VIM, Institut de la Recherche Agronomique (France)

    2013-05-15

    Antibiotic resistance has impelled the research for new agents that can inhibit bacterial growth without showing cytotoxic effects on humans and other species. We describe the synthesis and physicochemical characterization of nanostructured ZnMgO whose antibacterial activity was compared to its pure nano-ZnO and nano-MgO counterparts. Among the three oxides, ZnO nanocrystals-with the length of tetrapod legs about 100 nm and the diameter about 10 nm-were found to be the most effective antibacterial agents since both Gram-positive (B. subtilis) and Gram-negative (E. coli) bacteria were completely eradicated at concentration of 1 mg/mL. MgO nanocubes (the mean cube size {approx}50 nm) only partially inhibited bacterial growth, whereas ZnMgO nanoparticles (sizes corresponding to pure particles) revealed high specific antibacterial activity to Gram-positive bacteria at this concentration. Transmission electron microscopy analysis showed that B. subtilis cells were damaged after contact with nano-ZnMgO, causing cell contents to leak out. Our preliminary toxicological study pointed out that nano-ZnO is toxic when applied to human HeLa cells, while nano-MgO and the mixed oxide did not induce any cell damage. Overall, our results suggested that nanostructured ZnMgO, may reconcile efficient antibacterial efficiency while being a safe new therapeutic for bacterial infections.

  3. Eğitim Fakültelerinde Görev Yapmakta Olan Öğretim Elemanlarının Çokkültürlü Yeterlik Algılarının İncelenmesi Examining Multicultural Competence Perceptions of Education Faculty

    Directory of Open Access Journals (Sweden)

    Alper BAŞBAY

    2013-03-01

    Full Text Available Multicultural education is a learning and teaching approach thatis based on democratic belief and values. The main assumption is toconstruct the learning and teaching process that encourages culturalpluralism and respects different cultures in a common sense. It isinevitable that teachers who work in the primary and the secondaryschools have to provide multicultural environments for students whohave different cultural backgrounds. In this manner it is required toidentify the Education faculty’s, who train teacher candidates,perceptions about multiculturalism. In the present study Educationfaculties’ perceptions regarding multicultural awareness, multiculturalknowledge and multicultural skill levels and whether these competencylevels show significant differences with respect to various variables wereexamined. 347 faculties (176 female, 171 male from 63 universitiesparticipated in the study. The data of the study was collected by“Perceptions of Multicultural Competence Scale” developed by theresearchers. In order to analyze data multivariate ANOVA (MANOVAwas used. According to the results, it was seen that Education faculties’perceived multicultural competencies were high. As the other result ofthe study, regarding perceived multicultural competencies although nosignificant differences were found in terms of academic position,geographical region, job experience and place lived for most of their livesvariables, two demographic variables namely gender and internationalexperience were found to be statistically significant. Female faculties’cultural awareness and skill levels were higher than male faculty andmulticultural competence perceptions of faculty who has internationalexperience were higher than faculty who does not. Çokkültürlü eğitim, demokratik inanç ve değerler üzerine kurulubir öğrenme ve öğretme yaklaşımıdır. Öğrenme ve öğretme sürecininkültürel çoğulculuğu teşvik edecek ve farklı kültürlere sayg

  4. Catalysis and Downsizing in Mg-Based Hydrogen Storage Materials

    Directory of Open Access Journals (Sweden)

    Jianding Li

    2018-02-01

    Full Text Available Magnesium (Mg-based materials are promising candidates for hydrogen storage due to the low cost, high hydrogen storage capacity and abundant resources of magnesium for the realization of a hydrogen society. However, the sluggish kinetics and strong stability of the metal-hydrogen bonding of Mg-based materials hinder their application, especially for onboard storage. Many researchers are devoted to overcoming these challenges by numerous methods. Here, this review summarizes some advances in the development of Mg-based hydrogen storage materials related to downsizing and catalysis. In particular, the focus is on how downsizing and catalysts affect the hydrogen storage capacity, kinetics and thermodynamics of Mg-based hydrogen storage materials. Finally, the future development and applications of Mg-based hydrogen storage materials is discussed.

  5. Theoretical Limiting Potentials in Mg/O2 Batteries

    DEFF Research Database (Denmark)

    Smith, Jeffrey G.; Naruse, Junichi; Hiramatsu, Hidehiko

    2016-01-01

    A rechargeable battery based on a multivalent Mg/O2 couple is an attractive chemistry due to its high theoretical energy density and potential for low cost. Nevertheless, metal-air batteries based on alkaline earth anodes have received limited attention and generally exhibit modest performance....... In addition, many fundamental aspects of this system remain poorly understood, such as the reaction mechanisms associated with discharge and charging. The present study aims to close this knowledge gap and thereby accelerate the development of Mg/O2 batteries by employing first-principles calculations...... by the presence of large thermodynamic overvoltages. In contrast, MgO2-based cells are predicted to be much more efficient: superoxide-terminated facets on MgO2 crystallites enable low overvoltages and round-trip efficiencies approaching 90%. These data suggest that the performance of Mg/O2 batteries can...

  6. Microstructure and properties of Mg-Al binary alloys

    Directory of Open Access Journals (Sweden)

    ZHENG Wei-chao

    2006-11-01

    Full Text Available The effects of different amounts of added Al, ranging from 1 % to 9 %, on the microstructure and properties of Mg-Al binary alloys were investigated. The results showed that when the amount of added Al is less than 5%, the grain size of the Mg-Al binary alloys decreases dramatically from 3 097 μm to 151 μm with increasing addition of Al. Further addition of Al up to 9% makes the grain size decrease slowly to 111 μm. The α-Mg dendrite arms are also refined. Increasing the amount of added Al decreases the hot cracking susceptibility of the Mg-Al binary alloys remarkably, and enhances the micro-hardness of the α-Mg matrix.

  7. Characterization of Mg-containing hydroxyapatites synthesized by combustion method

    Science.gov (United States)

    Kaygili, Omer; Keser, Serhat; Bulut, Niyazi; Ates, Tankut

    2018-05-01

    In the present paper, Mg-substituted hydroxyapatites with the morphology, composed of the stacked plate- and rod-like structures, were prepared at the temperature of 600 °C by combustion method using glycerine as a fuel. A significant decrease in the crystallite size values calculated for both Scherrer and Williamson-Hall methods is found. The crystallinity, lattice parameter of a, stress and anisotropic energy density values decreased by adding of Mg, whereas the lattice strain increased. The amount of HAp phase decreases with increasing amount of Mg and the β-tricalcium phosphate content increases. Mg incorporation the apatitic structure was detected. Depending on the increase in Mg content, Ca-deficiency was observed.

  8. Resetting of Mg isotopes between calcite and dolomite during burial metamorphism: Outlook of Mg isotopes as geothermometer and seawater proxy

    Science.gov (United States)

    Hu, Zhongya; Hu, Wenxuan; Wang, Xiaomin; Lu, Yizhou; Wang, Lichao; Liao, Zhiwei; Li, Weiqiang

    2017-07-01

    Magnesium isotopes are an emerging tool to study the geological processes recorded in carbonates. Calcite, due to its ubiquitous occurrence and the large Mg isotope fractionation associated with the mineral, has attracted great interests in applications of Mg isotope geochemistry. However, the fidelity of Mg isotopes in geological records of carbonate minerals (e.g., calcite and dolomite) against burial metamorphism remains poorly constrained. Here we report our investigation on the Mg isotope systematics of a dolomitized Middle Triassic Geshan carbonate section in eastern China. Magnesium isotope analysis was complemented by analyses of Sr-C-O isotopic compositions, major and trace element concentrations, and petrographic and mineralogical features. Multiple lines of evidence consistently indicated that post-depositional diagenesis of carbonate minerals occurred to the carbonate rocks. Magnesium isotope compositions of the carbonate rocks closely follow a mixing trend between a high δ26Mg dolomite end member and a low δ26Mg calcite end member, irrespective of sample positions in the section and calcite/dolomite ratio in the samples. By fitting the measured Mg isotope data using a two-end member mixing model, an inter-mineral Δ26Mgdolomite-calcite fractionation of 0.72‰ was obtained. Based on the experimentally derived Mg isotope fractionation factors for dolomite and calcite, a temperature of 150-190 °C was calculated to correspond to the 0.72‰ Δ26Mgdolomite-calcite fractionation. Such temperature range matches with the burial-thermal history of the local strata, making a successful case of Mg isotope geothermometry. Our results indicate that both calcite and dolomite had been re-equilibrated during burial metamorphism, and based on isotope mass balance of Mg, the system was buffered by dolomite in the section. Therefore, burial metamorphism may reset Mg isotope signature of calcite, and Mg isotope compositions in calcite should be dealt with caution in

  9. Effect of Mg on the Microstructure and Corrosion Resistance of the Continuously Hot-Dip Galvanizing Zn-Mg Coating

    Directory of Open Access Journals (Sweden)

    Anping Dong

    2017-08-01

    Full Text Available The microstructure of continuously hot-dip galvanizing Zn-Mg coating was investigated in order to obtain the mechanism of the effects of Mg on the corrosion resistance. In this paper, the vertical section of the Zn-0.20 wt % Al-Mg ternary phase diagram near the Al-low corner was calculated. The results indicates that the phase composition of the Zn-0.20 wt % Al-Mg ternary phase diagram near the Al-low corner is the same as Zn-Mg binary phase diagram, suggesting Al in the Zn-Mg (ZM coatings mainly concentrates on the interfacial layer between the coating and steel substrate. The microstructure of continuously hot-dip galvanizing ZM coatings with 0.20 wt % Al containing 1.0–3.0 wt % Mg was investigated using tunneling electron microscopy (TEM. The morphology of Zn in the coating changes from bulk to strip and finally to mesh-like, and the MgZn2 changes from rod-like to mesh-like with the Mg content increasing. Al in the ZM coatings mainly segregates at the Fe2Al5 inhibition layer and the Mg added to the Zn bath makes this inhibition layer thinner and uneven. Compared to GI coating, the time of the first red rust appears increases by more than two-fold and expansion rate of red rust reduces by more than four-fold in terms of salt spray experiment. The ZM coating containing 2.0 wt % Mg has the best corrosion resistance. The enhanced corrosion resistance of ZM coatings mainly depends on different corrosion products.

  10. Effect of Mg content on microstructure and corrosion behavior of hot dipped Zn–Al–Mg coatings

    Energy Technology Data Exchange (ETDEWEB)

    Yao, Caizhen; Lv, Haibing [Research Centre of Laser Fusion, CAEP, P.O.Box 919-988-5, Mianyang, Sichuan 621900 (China); Zhu, Tianping [Department of Chemical and Materials Engineering, The University of Auckland, PB 92019, Auckland 1142 (New Zealand); Zheng, Wanguo [Research Centre of Laser Fusion, CAEP, P.O.Box 919-988-5, Mianyang, Sichuan 621900 (China); Yuan, Xiaodong, E-mail: xdyuan@caep.cn [Research Centre of Laser Fusion, CAEP, P.O.Box 919-988-5, Mianyang, Sichuan 621900 (China); Gao, Wei, E-mail: w.gao@auckland.ac.nz [Department of Chemical and Materials Engineering, The University of Auckland, PB 92019, Auckland 1142 (New Zealand)

    2016-06-15

    In this article, Zn–Al–Mg coatings were prepared by hot dipping method. The surface morphology, cross–section microstructure, microhardness, composition, corrosion behaviour of ZAM coatings were investigated by using X–ray diffraction (XRD), Optical microscope, Environmental scanning electron microscopy equipped with EDS (FESEM–EDS), Microhardness tester and Electrochemical analysis respectively. Corrosion test was also performed in a standard salt fog spray chamber. Microstructure studies indicates that Zn grain size was refined and eutectic areas at Zn grain boundary areas increased with increasing Mg content. ZA5M1.5 and ZA5M2 coatings have two distinct layers. Mg tends to exist in the outer layer while Al is in the inner layer. The inner layer is composed of Al{sub 5}Fe{sub 2}Zn{sub 0.4} intermetallic, which may to contribute to the microhardness. The outer layer is Zn grains surrounded by Zn–Mg etutectics, which may improve the corrosion resistance. The microhardness is more than 700 HV{sub 50g} for Al-rich layer and around 151 HV{sub 25g} for Mg-rich layer. The improved corrosion resistance of Zn–5%Al-1.5%Mg coating comes from the corrosion product of flocculent type simonkolleite, which prolongs the micro-path and impedes the movement of O{sub 2} and H{sub 2}O, ultimately retards the overall corrosion process. - Highlights: • Two-layer structured Zn–Al–Mg coatings were prepared by hot dipping method. • Mg exists in the outer layer while Al exists in the inner layer of Zn–Al–Mg coating. • Zn–Al–Mg coating has better protective ability than Zn and Zn–Al coatings. • The Mg-modified simonkolleite is the reason of the enhanced corrosion resistance.

  11. Mg doping of GaN by molecular beam epitaxy

    International Nuclear Information System (INIS)

    Lieten, R R; Buchowicz, G; Dubon, O; Motsnyi, V; Zhang, L; Cheng, K; Leys, M; Degroote, S; Borghs, G

    2011-01-01

    We present a systematic study on the influence of growth conditions on the incorporation and activation of Mg in GaN layers grown by plasma-assisted molecular beam epitaxy. We show that high quality p-type GaN layers can be obtained on GaN-on-silicon templates. The Mg incorporation and the electrical properties have been investigated as a function of growth temperature, Ga : N flux ratio and Mg : Ga flux ratio. It was found that the incorporation of Mg and the electrical properties are highly sensitive to the Ga : N flux ratio. The highest hole mobility and lowest resistivity were achieved for slightly Ga-rich conditions. In addition to an optimal Ga : N ratio, an optimum Mg : Ga flux ratio was also observed at around 1%. We observed a clear Mg flux window for p-type doping of GaN : 0.31% 17 cm -3 and a mobility of 15 cm 2 V -1 s -1 . Temperature-dependent Hall effect measurements indicate an acceptor depth in these samples of 100 meV for a hole concentration of 5.5 x 10 17 cm -3 . The corresponding Mg concentration is 5 x 10 19 cm -3 , indicating approximately 1% activation at room temperature. In addition to continuous growth of Mg-doped GaN layers we also investigated different modulated growth procedures. We show that a modulated growth procedure has only limited influence on Mg doping at a growth temperature of 800 deg. or higher. This result is thus in contrast to previously reported GaN : Mg doping at much lower growth temperatures of 500 deg. C.

  12. Pharmacokinetic characterization of three novel 4-mg nicotine lozenges
.

    Science.gov (United States)

    Sukhija, Manpreet; Srivastava, Reena; Kaushik, Aditya

    2018-03-01

    Nicotine replacement therapy (NRT) increases the probability of smoking cessation. This study was conducted to determine if three prototype 4-mg nicotine lozenges produced locally in India were bioequivalent to a globally marketed reference product, Nicorette® 4-mg nicotine lozenge. Healthy adult smokers (N = 39) were treated with three prototype 4-mg nicotine lozenges in comparison with a reference 4-mg lozenge in this single-center, randomized, open-label, single-dose, 4-way crossover study. Pharmacokinetic sampling was obtained to test for bioequivalence using maximal plasma concentration (Cmax) and extent of absorption (AUC0-t). Secondarily, AUC;0-∞, time to maximal plasma concentration (tmax), half-life (T1/2), elimination rate constant (Kel), and safety of the prototype lozenges versus the reference lozenge were compared. Each prototype 4-mg nicotine lozenge was found to be bioequivalent to the reference 4-mg nicotine lozenge based on the ratio of geometric means and 90% confidence intervals for Cmax, AUC0-t, and AUC;0-∞. Although tmax; was significantly longer for prototype III, all four lozenges achieved maximum plasma nicotine concentrations at a median of 1.5 hours. The safety profiles of the three prototype 4-mg lozenges did not differ from that of the 4-mg reference product. Each prototype 4-mg nicotine lozenge was bioequivalent to the reference 4-mg nicotine lozenge and was well tolerated. Furthermore, as these bioequivalent prototypes differed in in-vitro dissolution profiles, these data suggest that performance from the in -vitro method deployed is not a firm predictor of pharmacokinetic behavior.
.

  13. In vitro degradation and electrochemical corrosion evaluations of microarc oxidized pure Mg, Mg-Ca and Mg-Ca-Zn alloys for biomedical applications.

    Science.gov (United States)

    Pan, Yaokun; He, Siyu; Wang, Diangang; Huang, Danlan; Zheng, Tingting; Wang, Siqi; Dong, Pan; Chen, Chuanzhong

    2015-02-01

    Calcium phosphate (CaP) ceramic coatings were fabricated on pure magnesium (Mg) and self-designed Mg-0.6Ca, Mg-0.55Ca-1.74Zn alloys by microarc oxidation (MAO). The coating formation, growth and biomineralization mechanisms were discussed. The coating degradability and bioactivity were evaluated by immersion tests in trishydroxymethyl-aminomethane hydrochloric acid (Tris-HCl) buffer and simulated body fluid (SBF) solutions, respectively. The coatings and corrosion products were characterized by scanning electron microscope (SEM), X-ray diffractometer (XRD), X-ray photoelectron spectrometer (XPS) and fourier transform infrared spectrometer (FT-IR). The electrochemical workstation was used to investigate the electrochemical corrosion behaviors of substrates and coatings. Results showed that Mg-0.55Ca-1.74Zn alloy exhibits the highest mechanical strength and electrochemical corrosion resistance among the three alloys. The MAO-coated Mg-0.55Ca-1.74Zn alloy has the potential to be served as a biodegradable implant. Copyright © 2014 Elsevier B.V. All rights reserved.

  14. Improved hydrogen sorption kinetics in wet ball milled Mg hydrides

    Energy Technology Data Exchange (ETDEWEB)

    Meng, Li

    2011-05-04

    In this work, wet ball milling method is used in order to improve hydrogen sorption behaviour due to its improved microstructure of solid hydrogen materials. Compared to traditional ball milling method, wet ball milling has benefits on improvement of MgH{sub 2} microstructure and further influences on its hydrogen sorption behavior. With the help of solvent tetrahydrofuran (THF), wet ball milled MgH{sub 2} powder has much smaller particle size and its specific surface area is 7 times as large as that of dry ball milled MgH{sub 2} powder. Although after ball milling the grain size is decreased a lot compared to as-received MgH{sub 2} powder, the grain size of wet ball milled MgH{sub 2} powder is larger than that of dry ball milled MgH{sub 2} powder due to the lubricant effect of solvent THF during wet ball milling. The improved particle size and specific surface area of wet ball milled MgH{sub 2} powder is found to be determining its hydrogen sorption kinetics especially at relatively low temperatures. And it also shows good cycling sorption behavior, which decides on its industrial applicability. With three different catalysts MgH{sub 2} powder shows improved hydrogen sorption behavior as well as the cyclic sorption behavior. Among them, the Nb{sub 2}O{sub 5} catalyst is found to be the most effective one in this work. Compared to the wet ball milled MgH{sub 2} powder, the particle size and specific surface area of the MgH{sub 2} powder with catalysts are similar to the previous ones, while the grain size of the MgH{sub 2} with catalysts is much finer. In this case, two reasons for hydrogen sorption improvement are suggested: one is the reduction of the grain size. The other may be as pointed out in some literatures that formation of new oxidation could enhance the hydrogen sorption kinetics, which is also the reason why its hydrogen capacity is decreased compared to without catalysts. After further ball milling, the specific surface area of wet ball milled Mg

  15. Synthesis, crystal growth and structure of Mg containing β-rhombohedral boron: MgB17.4

    International Nuclear Information System (INIS)

    Adasch, Volker; Hess, Kai-Uwe; Ludwig, Thilo; Vojteer, Natascha; Hillebrecht, Harald

    2006-01-01

    For the first time, single crystals of Mg containing β-rhombohedral boron MgB 17.4 were synthesised from the elements in a Mg/Cu melt at 1600deg. C. The crystal structure determined by the refinement of single crystal data (space group R-3m, a=10.991(2)A, c=24.161(4)A, 890 reflections, 123 variables, R 1 (F)=0.049, wR 2 (I)=0.122) improves and modifies the former structure model derived from earlier investigations on powder samples. Mg is located on four different positions with partial occupation. While the occupation of the sites D (53.3%), E (91%) and F (7.2%) is already known from other boron-rich borides related to β-rhombohedral boron, the occupation of the fourth position (18h, 6.7%) is observed for the first time. Two boron positions show partial occupation. The summation reveals the composition MgB 17.4 and Mg 5.85 B 101.9 , respectively, confirmed by WDX measurements. The single crystals of MgB 17.4 show the highest Mg content ever found. Preliminary measurements indicate no superconductivity

  16. Influence of a transition metal atom on the geometry and electronic structure of Mg and Mg-H clusters

    International Nuclear Information System (INIS)

    Siretskiy, M.Yu.; Shelyapina, M.G.; Fruchart, D.; Miraglia, S.; Skryabina, N.E.

    2009-01-01

    We report on the study of (MgH 2 ) n + M complexes (M = Ti or Ni) carried out within the framework of the cluster density functional theory (DFT) method. The influence of such transition metal atoms on the cluster geometry and electronic structure is discussed considering the stability of MgH 2 hydride.

  17. Ab-initio calculations of semiconductor MgGeP{sub 2} and MgGeAs{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Kocak, B.; Ciftci, Y.O., E-mail: yasemin@gazi.edu.tr

    2016-05-15

    Highlights: • MgGeP{sub 2} and MgGeAs{sub 2} are semiconductor compounds. • MgGeP{sub 2} and MgGeAs{sub 2} are energetically, mechanically and dynamically stable. • The electronic charge density contour plot shows that the nature of bonding is a mixture of ionic-covalent. - Abstract: In this study, we focus on structural, electronic, elastic, lattice dynamic and optic properties of MgGeP{sub 2} and MgGeAs{sub 2} using ab-initio density-functional theory (DFT) within Armiento-Mattson 2005 (AM05) scheme of the generalized gradient approximation (GGA) for the exchange-correlation potential. Our computed structural results are in reasonable agreement with the literature. The band gap of these compounds is predicted to be direct. Our elastic results prove that these compounds are mechanically stable. The obtained phonon spectra of MgGeP{sub 2} and MgGeAs{sub 2} do not exhibit any significant imaginary branches using GGA-AM05 for the exchange-correlation approximation. Further analysis of the optical response of the dielectric functions, optical reflectivity, refractive index, extinction coefficient and electron energy loss delves into for the energy range of 0–22.5 eV. It motivated that there exists an optical polarization anisotropy of these compounds for optoelectronic device applications.

  18. Thermal behaviour of Cu-Mg-Mn and Ni-Mg-Mn layered double hydroxides and characterization of formed oxides

    Czech Academy of Sciences Publication Activity Database

    Kovanda, F.; Grygar, Tomáš; Dorničák, V.; Rojka, T.; Bezdička, Petr; Jirátová, Květa

    2005-01-01

    Roč. 28, 1-4 (2005), s. 121-136 ISSN 0169-1317 Institutional research plan: CEZ:AV0Z40320502 Keywords : Cu-Mg-Mn basic carbonates * Ni-Mg-Mn hydrotalcite Subject RIV: CA - Inorganic Chemistry Impact factor: 1.324, year: 2005

  19. Ipilimumab 10 mg/kg versus ipilimumab 3 mg/kg in patients with unresectable or metastatic melanoma

    DEFF Research Database (Denmark)

    Ascierto, Paolo A; Del Vecchio, Michele; Robert, Caroline

    2017-01-01

    of ipilimumab 10 mg/kg versus 3 mg/kg. METHODS: This randomised, double-blind, multicentre, phase 3 trial was done in 87 centres in 21 countries worldwide. Patients with untreated or previously treated unresectable stage III or IV melanoma, without previous treatment with BRAF inhibitors or immune checkpoint...

  20. Phase diagrams of aluminium alloys of Al-Cu-Mg, Al-Mg-Si-Cu, and Al-Mg-Li system

    International Nuclear Information System (INIS)

    Ber, L.B.; Kaputkin, E.Ya.

    2001-01-01

    Isothermal diagrams of phase transformations (DPT) and temperature-time charts (TTC) of variation of electric conductivity and of mechanical features at tension were plotted following thermal treatment according to the pattern of direct hardening and ageing and according to the pattern of normal aging for D16 commercial alloy, Al-Cu-Mg model alloy of the same system, AD37 commercial alloys of Al-Mg-Si-Cu and 1424 one of Al-Li-Mg system. Phase transformations were studied by means of fluorescence electron microscopy, micro-X-ray spectral analysis, X-ray phase analysis of single crystals and polycrystals and differential scanning calorimetry. For every alloy comparison of TTC and DPT enables to clarity the mechanism of phase composition effect on features and to optimize conditions of hardening cooling and ageing [ru

  1. In vivo and in vitro degradation comparison of pure Mg, Mg-10Gd and Mg-2Ag: a short term study

    Directory of Open Access Journals (Sweden)

    I Marco

    2017-02-01

    Full Text Available The purpose of this study was to compare short term in vitro and in vivo biodegradation studies with low purity Mg (> 99.94 %, Mg-10Gd and Mg-2Ag designed for biodegradable implant applications. Three in vitro testing conditions were applied, using (i phosphate buffered saline (PBS, (ii Hank’s balanced salt solution (HBSS and (iii Dulbecco’s modified eagle medium (DMEM in 5 % CO2 under sterile conditions. Gas evolution and mass loss (ML were assessed, as well as the degradation layer, by elemental mapping and scanning electron microscopy (SEM. In vivo, implantations were performed on male Sprague-Dawley rats evaluating both, gas cavity volume and implant volume reduction by micro-computed tomography (µCT, 7 d after implantation. Samples were produced by casting, solution heat treatment and extrusion in disc and pin shape for the in vitro and in vivo experiments, respectively. Results showed that when the processing of the Mg sample varied, differences were found not only in the alloy impurity content and the grain size, but also in the corrosion behaviour. An increase of Fe and Ni or a large grain size seemed to play a major role in the degradation process, while the influence of alloying elements, such as Gd and Ag, played a secondary role. Results also indicated that cell culture conditions induced degradation rates and degradation layer elemental composition comparable to in vivo conditions. These in vitro and in vivo degradation layers consisted of Mg hydroxide, Mg-Ca carbonate and Ca phosphate.

  2. Effect of solution concentration on sealing treatment of Mg-Al hydrotalcite film on AZ91D Mg alloy

    Directory of Open Access Journals (Sweden)

    Qiangsheng Dong

    2017-09-01

    Full Text Available Cerium-based sealing treatment was developed for Mg-Al hydrotalcite film on AZ91D Mg alloy, and the influence of cerium salt solution was investigated to modify the surface integrity and corrosion resistance. Scanning electron microscope (SEM and X-ray diffraction (XRD measurements were carried out to analyze the surface morphology and phase composition. The corrosion resistance of Mg-Al hydrotalcite film after sealing treatment was evaluated by the polarization curve and electrochemical impedance spectroscopy (EIS tests. The results showed that lower concentration of Ce-containing solution was beneficial to seal the micro-cracks on Mg-Al hydrotalcite film, and improve the surface integrity and corrosion resistance; higher concentration of Ce-containing solution could seal fewer micro-cracks, and the corrosion resistance was decreased owing to the disintegration of Mg-Al hydrotalcite film.

  3. Phase-field simulations of dendrite morphologies and selected evolution of primary {alpha}-Mg phases during the solidification of Mg-rich Mg-Al-based alloys

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Mingyue [Key Laboratory for Advanced Materials Processing Technology, Ministry of Education, Department of Mechanical Engineering, Tsinghua University, Beijing 100084 (China); Jing, Tao; Liu, Baicheng [Key Laboratory for Advanced Materials Processing Technology, Ministry of Education, Department of Mechanical Engineering, Tsinghua University, Beijing 100084 (China)

    2009-10-15

    A formulation of solid-liquid interfacial thermodynamic and kinetic anisotropic characteristics for hexagonal close-packed metals is proposed. The two- and three-dimensional dendritic growth of primary Mg in undercooled Mg-Al alloy melts is modeled using the phase-field method, based on a combination of crystallographic lattice symmetry and experimental observations. The morphologies of three-dimensional dendrites are obtained and the calculated results show intricately hierarchical branched structures. The excess free energy of the solution system is based on the Redlich-Kister model.

  4. Phase-field simulations of dendrite morphologies and selected evolution of primary α-Mg phases during the solidification of Mg-rich Mg-Al-based alloys

    International Nuclear Information System (INIS)

    Wang, Mingyue; Jing, Tao; Liu, Baicheng

    2009-01-01

    A formulation of solid-liquid interfacial thermodynamic and kinetic anisotropic characteristics for hexagonal close-packed metals is proposed. The two- and three-dimensional dendritic growth of primary Mg in undercooled Mg-Al alloy melts is modeled using the phase-field method, based on a combination of crystallographic lattice symmetry and experimental observations. The morphologies of three-dimensional dendrites are obtained and the calculated results show intricately hierarchical branched structures. The excess free energy of the solution system is based on the Redlich-Kister model.

  5. Atorvastatin 10 mg plus ezetimibe 10mg compared with atorvastatin 20 mg: impact on the lipid profile in Japanese patients with abnormal glucose tolerance and coronary artery disease.

    Science.gov (United States)

    Uemura, Yusuke; Watarai, Masato; Ishii, Hideki; Koyasu, Masayoshi; Takemoto, Kenji; Yoshikawa, Daiji; Shibata, Rei; Matsubara, Tatsuaki; Murohara, Toyoaki

    2012-01-01

    Oxidized low-density lipoprotein (LDL) cholesterol is a sensitive lipid marker for predicting atherosclerosis. Ezetimibe and statins are reported to decrease both LDL cholesterol and oxidized LDL cholesterol. This prospective randomized open-label crossover study compared combination therapy with atorvastatin plus ezetimibe versus high-dose atorvastatin monotherapy. Changes in serum lipids, including malondialdehyde-modified LDL (MDA-LDL) as a representative form of oxidized LDL cholesterol, and glucose metabolism were assessed. The subjects were 39 Japanese patients with coronary artery disease and type 2 diabetes or impaired glucose tolerance who were taking 10 mg/day of atorvastatin (30 men and 9 women with a mean age of 67.8 years). They were randomized to a group that first received add-on ezetimibe (10 mg/day) or a group that first received atorvastatin monotherapy at a higher dose of 20 mg/day. Both treatments were given for 12 weeks each in a crossover fashion. Add-on ezetimibe significantly decreased MDA-LDL (109.0 ± 31.9 mg/dl to 87.7 ± 29.4 mg/dl, p=0.0009), while up-titration of atorvastatin did not. The decrease with add-on ezetimibe was significantly greater than with up-titration of atorvastatin (p=0.0006). Total cholesterol and LDL cholesterol were significantly decreased by both treatments, but the percent reduction with add-on ezetimibe was significantly greater (pHigh-density lipoprotein cholesterol was significantly increased by both treatments and there was no significant difference between them. The apolipoprotein B/apolipoprotein A-I ratio and remnant-like particle cholesterol were only significantly decreased by add-on ezetimibe. Both treatments caused similar elevation of hemoglobin A(1c). In Japanese patients with type 2 diabetes or impaired glucose tolerance and coronary artery disease, adding ezetimibe (10 mg/day) to atorvastatin (10 mg/day) significantly improved the lipid profile compared with atorvastatin monotherapy at 20 mg

  6. Synthesis and crystal structure of MgB12

    International Nuclear Information System (INIS)

    Adasch, Volker; Hess, Kai-Uwe; Ludwig, Thilo; Vojteer, Natascha; Hillebrecht, Harald

    2006-01-01

    Single crystals of MgB 12 were synthesized from the elements in a Mg/Cu melt at 1600deg. C. MgB 12 crystallizes orthorhombic in space group Pnma with a=16.632(3)A, b=17.803(4)A and c=10.396(2)A. The crystal structure (Z=30, 5796 reflections, 510 variables, R 1 (F)=0.049, wR 2 (I)=0.134) consists of a three dimensional net of B 12 icosahedra and B 21 units in a ratio 2:1. The B 21 units are observed for the first time in a solid compound. Mg is on positions with partial occupation. The summation reveals the composition MgB 12.35 or Mg 0.97 B 12 , respectively. This is in good agreement with the value of MgB 11.25 as expected by electronic reasons to stabilize the boron polyhedra B 12 2- and B 21 4-

  7. Comparison of 1 mg and 2 mg overnight dexamethasone suppression tests for the screening of Cushing's syndrome in obese patients.

    Science.gov (United States)

    Sahin, Mustafa; Kebapcilar, Levent; Taslipinar, Abdullah; Azal, Omer; Ozgurtas, Taner; Corakci, Ahmet; Akgul, Emin Ozgur; Taslipinar, Mine Yavuz; Yazici, Mahmut; Kutlu, Mustafa

    2009-01-01

    Obesity is currently a major public health problem and one of the potential underlying causes of obesity in a minority of patients is Cushing's syndrome (CS). Traditionally, the gold standard screening test for CS is 1 mg dexamethasone overnight suppression test. However, it is known that obese subjects have high false positive results with this test. We have therefore compared the 1 mg and 2 mg overnight dexamethasone suppression tests in obese subjects. Patients whose serum cortisol after ODST was >50 nM underwent and a low-dose dexamethasone suppression test (LDDST); 24-hour urine cortisol was collected for basal urinary free cortisol (UFC). For positive results after overnight 1-mg dexamethasone suppression test we also performed the overnight 2-mg dexamethasone suppression test. We prospectively evaluated 100 patients (22 men and 78 women, ranging in age from 17 to 73 years with a body mass index (BMI) >30 kg/m2 who had been referred to our hospital-affiliated endocrine clinic because of simple obesity. Suppression of serum cortisol to suppression. Thyroid function tests, lipid profiles, homocysteine, antithyroglobulin, anti-thyroid peroxidase antibody levels, vitamin B12, folate levels, insulin resistance [by homeostasis model assessment (HOMA)] and 1.0 mg postdexamethasone (postdex) suppression cortisol levels were measured. We found an 8% false-positive rate in 1 mg overnight test and 2% in 2 mg overnight test (p=0.001). There was no correlation between the cortisol levels after ODST and other parameters. Our results indicate that the 2 mg overnight dexamethasone suppression test (ODST) is more convenient and accurate than 1-mg ODST as a screening test for excluding CS in subjects with simple obesity.

  8. Mg{sub 2}Sn heterostructures on Si(111) substrate

    Energy Technology Data Exchange (ETDEWEB)

    Dózsa, L., E-mail: dozsa@mfa.kfki.hu [Institute of Technical Physics and Materials Science, Centre for Energy Research, Hungarian Academy of Sciences, 1525 Budapest Pf, 49 (Hungary); Galkin, N.G. [Institute of Automation and Control Processes of FEB RAS, 5 Radio St., Vladivostok 690041 (Russian Federation); Far Eastern Federal University, 8 Sukhanova St., Vladivostok 690950 (Russian Federation); Pécz, B.; Osváth, Z.; Zolnai, Zs. [Institute of Technical Physics and Materials Science, Centre for Energy Research, Hungarian Academy of Sciences, 1525 Budapest Pf, 49 (Hungary); Németh, A. [Wigner Research Centre for Physics, Institute for Particle and Nuclear Physics, 1525 Budapest, P.O.B. 49 (Hungary); Galkin, K.N.; Chernev, I.M. [Institute of Automation and Control Processes of FEB RAS, 5 Radio St., Vladivostok 690041 (Russian Federation); Dotsenko, S.A. [Institute of Automation and Control Processes of FEB RAS, 5 Radio St., Vladivostok 690041 (Russian Federation); Far Eastern Federal University, 8 Sukhanova St., Vladivostok 690950 (Russian Federation)

    2017-05-31

    Highlights: • Investigations show that the nanostructures have significant changes during the applied regular experimental investigations. • It is especially true for transmittance electron microscopy, where the investigated layers have to be thinned near to the nanostructure size. • The time order of the applied experimental investigation has a dominant effect on the experimetal results. - Abstract: Thin un-doped and Al doped polycrystalline Mg-stannide films consisting mainly of Mg{sub 2}Sn semiconductor phase have been grown by deposition of Sn-Mg multilayers on Si(111) p-type wafers at room temperature and annealing at 150 °C. Rutherford backscattering measurement spectroscopy (RBS) were used to determine the amount of Mg and Sn in the structures. Raman spectroscopy has shown the layers contain Mg{sub 2}Sn phase. Cross sectional transmission electron microscopy (XTEM) measurements have identified Mg{sub 2}Sn nanocrystallites in hexagonal and cubic phases without epitaxial orientation with respect to the Si(111) substrate. Significant oxygen concentration was found in the layer both by RBS and TEM. The electrical measurements have shown laterally homogeneous conductivity in the grown layer. The undoped Mg{sub 2}Sn layers show increasing resistivity with increasing temperature indicating the scattering process dominates the resistance of the layers, i.e. large concentration of point defects was generated in the layer during the growth process. The Al doped layer shows increase of the resistance at low temperature caused by freeze out of free carriers in the Al doped Mg{sub 2}Sn layer. The measurements indicate the necessity of protective layer grown over the Mg{sub 2}Sn layers, and a short time delay between sample preparation and cross sectionalTEM analysis, since the unprotected layer is degraded by the interaction with the ambient.

  9. Pulse laser irradiation into superconducting MgB2 detector

    International Nuclear Information System (INIS)

    Fujiwara, Daisuke; Miki, Shigehito; Satoh, Kazuo; Yotsuya, Tsutomu; Shimakage, Hisashi; Wang, Zhen; Okayasu, Satoru; Katagiri, Masaki; Machida, Masahiko; Kato, Masaru; Ishida, Takekazu

    2005-01-01

    We performed 20-ps pulse laser irradiation experiments on a MgB 2 neutron detector to know a thermal-relaxation process for designing a MgB 2 neutron detector. The membrane-type structured MgB 2 device was fabricated to minimize the heat capacity of sensing part of a detector as well as to enhance its sensitivity. We successfully observed a thermal-relaxation signal resulting from pulse laser irradiation by developing a detection circuit. The response time was faster than 1 μs, meaning that the detector would be capable of counting neutrons at a rate of more than 10 6 events per second

  10. Interaction of hydrogen with an Mg-Al alloy

    International Nuclear Information System (INIS)

    Andreasen, A.; Sorensen, M.B.; Burkarl, R.; Moller, B.; Molenbroek, A.M.; Pedersen, A.S.; Andreasen, J.W.; Nielsen, M.M.; Jensen, T.R.

    2005-01-01

    The interaction of hydrogen with an Mg-Al alloy pre-exposed to air have been studied with in situ time resolved X-ray powder diffraction. Phase fractions as a function of time are derived from series of consecutive diffraction patterns allowing kinetic analysis. The apparent activation energy for dehydrogenation of the Mg-Al alloy is found to be 160 kJ/mol. This is not significantly higher than for pure and fully activated Mg. It is suggested that the addition of Al improves the resistance towards oxygen contamination

  11. The role of Mg in the crystallization of monohydrocalcite

    Science.gov (United States)

    Rodriguez-Blanco, Juan Diego; Shaw, Samuel; Bots, Pieter; Roncal-Herrero, Teresa; Benning, Liane G.

    2014-02-01

    Monohydrocalcite is a member of the carbonate family which forms in Mg-rich environments at a wide range of Mg/Ca ratios Mg2+aq/Ca2+aq≥0.17stock solutions. However, its crystallite and particle size are inversely proportional to these parameters. At high supersaturations (SIMHC = 3.89) nanometer-sized single crystals of monohydrocalcite form, while at low values (SIMHC = 2.43) the process leads to low-angle branching spherulites. Many carbonates produced during biomineralization form at similar conditions to most synthetic monohydrocalcites, and thus we hypothesize that some calcite or aragonite deposits found in the geologic record that have formed at high Mg/Ca ratios could be secondary in origin and may have originally formed via a metastable monohydrocalcite intermediate. High-Mg monohydrocalcite (χMgCO3 > 0.06) consists of individual nanometer-sized crystals (500 °C (Fig. 9b). Such high-Mg monohydrocalcites are uncommon in nature, but can be synthesized in the laboratory at high initial supersaturation levels (SI > 3.25). Low-Mg monohydrocalcite (χMgCO3 bonded to Mg, so it fully dehydrates at low temperatures (150-200 °C). They have the same composition as natural monohydrocalcites reported in the literature, and can be synthesized in the laboratory at lower supersaturation levels (SI relationships. Firstly, our on-line experiment shows an increase in nanocrystal sizes during the secondary crystallization of monohydrocalcite, which is coupled with a significant decrease in χMgCO3 (from ˜0.26 to ˜0.065). This corresponds to the transition from high- to low-Mg monohydrocalcite, suggesting that the former would be metastable and rapidly transforming to the latter, possibly triggered by the removal of Mg from aqueous solution. Secondly, Davis et al. (2000) determined that the solubility of Mg-calcite (Ca1-xMgxCO3; x = 0-0.20) varies by approximately half an order of magnitude depending on the Mg content of the solid (Ksp = 10-8.0-10-8.5). A similar

  12. Catalytic activity of Co-Mg-Al, Cu-Mg-Al and Cu-Co-Mg-Al mixed oxides derived from hydrotalcites in SCR of NO with ammonia

    Energy Technology Data Exchange (ETDEWEB)

    Chmielarz, Lucjan; Kustrowski, Piotr; Rafalska-Lasocha, Alicja [Faculty of Chemistry, Jagiellonian University, Ingardena 3, 30-060 Krakow (Poland); Majda, Dorota; Dziembaj, Roman [Regional Laboratory for Physicochemical Analyses and Structural Research, Ingardena 3, 30-060 Krakow (Poland)

    2002-01-10

    M-Mg-Al hydrotalcites (where M=Cu{sup 2+}, Co{sup 2+} and Cu{sup 2+}+Co{sup 2+}) with M ranging from 5 to 20% (as atomic ratio) were prepared by co-precipitation method. Obtained samples were characterised by XRD and TGA techniques. The influence of transition metal content on thermal decomposition of hydrotalcites was observed. Calcination of the hydrotalcites at 600C resulted in the formation of mixed oxides with surface areas in the range 71-154m{sup 2}/g. Calcined hydrotalcites were tested as catalysts in the selective reduction of NO with ammonia (NO-SCR). The catalytic activity depends on the kind of transition metal, as well as its content. For the NO-SCR the following reactivity order was found: Cu-Mg-Al>Cu-Co-Mg-Al>Co-Mg-Al. Temperature-programmed methods (TPD, TPSR, stop flow-TPD), as well as FT-IR spectroscopy have been applied to determine interaction of NO and NH{sub 3} molecules with the catalyst surface.

  13. Synthesis of Mg(OH)2, MgO, and Mg nanoparticles using laser ablation of magnesium in water and solvents

    Energy Technology Data Exchange (ETDEWEB)

    Tran, P.X.; Howard, B.H.; Martello, D.V.; Soong, Y.; Chyu, M.K.

    2008-01-01

    laser ablation of magnesium in deionized water (OW), solutions of OW and sodium dodecyl sulfate (50S) with different concentrations, acetone and 2-propanol has been conducted, The results showed that ablation in acetone and 2-propanol yielded MgO and Mg nanocrystallites as isolated particles and agglomerated chains probably intermixed with organic residues resulting from the alterationj decomposition of the solvents under the high-energy conditions. Brucite-like Mg(OH)2 particles were mainly produced by laser ablation of Mg in either OW or OW~SOS solutions. Ablation in OW yielded particles of fiber-like shapes having a diameter of about 5-lOnm and length as long as 150nm. Materials produced in DW-SOS solutions were composed of various size and shape particles, Some had rough surfaces with irregular shapes. Small particles were about 20-30nm and larger particles were about 120 nm. Particles with rod-like, triangular, and plate-like shapes were also observed.

  14. Synthesis of Mg(OH)2, MgO, and Mg nanoparticles using laser ablation of magnesium in water and solvents

    Energy Technology Data Exchange (ETDEWEB)

    Phuoc, Tran X. [National Energy Technology Lab. (NETL), Pittsburgh, PA, (United States); Howard, Bret. H. [National Energy Technology Lab. (NETL), Pittsburgh, PA, (United States); Martello, Donald V. [National Energy Technology Lab. (NETL), Pittsburgh, PA, (United States); Soong, Yee [National Energy Technology Lab. (NETL), Pittsburgh, PA, (United States); Chyu, Minking K. [Univ. of Pittsburgh, PA (United States)

    2008-11-01

    Laser ablation of magnesium in deionized water (DW), solutions of DW and sodium dodecyl sulfate (SDS) with different concentrations, acetone and 2-propanol has been conducted. The results showed that ablation in acetone and 2-propanol yielded MgO and Mg nanocrystallites as isolated particles and agglomerated chains probably intermixed with organic residues resulting from the alteration/decomposition of the solvents under the high-energy conditions. Brucite-like Mg(OH)2 particles were mainly produced by laser ablation of Mg in either DW or DW-SDS solutions. Ablation in DW yielded particles of fiber-like shapes having a diameter of about 5-10nm and length-as long as 150 nm. Materials produced in DW-SDS solutions were composed of various size and shape particles. Some had rough surfaces with irregular shapes. Small particles were about 20-30 nm and larger particles were about 120 nm. Particles with rodlike, triangular, and plate-like shapes were also observed.

  15. Synthesis of Mg(OH) 2, MgO, and Mg nanoparticles using laser ablation of magnesium in water and solvents

    Science.gov (United States)

    Phuoc, Tran X.; Howard, Bret. H.; Martello, Donald V.; Soong, Yee; Chyu, Minking K.

    2008-11-01

    Laser ablation of magnesium in deionized water (DW), solutions of DW and sodium dodecyl sulfate (SDS) with different concentrations, acetone and 2-propanol has been conducted. The results showed that ablation in acetone and 2-propanol yielded MgO and Mg nanocrystallites as isolated particles and agglomerated chains probably intermixed with organic residues resulting from the alteration/decomposition of the solvents under the high-energy conditions. Brucite-like Mg(OH) 2 particles were mainly produced by laser ablation of Mg in either DW or DW-SDS solutions. Ablation in DW yielded particles of fiber-like shapes having a diameter of about 5-10 nm and length as long as 150 nm. Materials produced in DW-SDS solutions were composed of various size and shape particles. Some had rough surfaces with irregular shapes. Small particles were about 20-30 nm and larger particles were about 120 nm. Particles with rod-like, triangular, and plate-like shapes were also observed.

  16. Defect kinetics in spinels: Long-time simulations of MgAl2O4, MgGa2O4, and MgIn2O4

    International Nuclear Information System (INIS)

    Uberuaga, B. P.; Voter, A. F.; Sickafus, K. E.; Bacorisen, D.; Smith, Roger; Ball, J. A.; Grimes, R. W.

    2007-01-01

    Building upon work in which we examined defect production and stability in spinels, we now turn to defect kinetics. Using temperature accelerated dynamics (TAD), we characterize the kinetics of defects in three spinel oxides: magnesium aluminate MgAl 2 O 4 , magnesium gallate MgGa 2 O 4 , and magnesium indate MgIn 2 O 4 . These materials have varying tendencies to disorder on the cation sublattices. In order to understand chemical composition effects, we first examine defect kinetics in perfectly ordered, or normal, spinels, focusing on point defects on each sublattice. We then examine the role that cation disorder has on defect mobility. Using TAD, we find that disorder creates local environments which strongly trap point defects, effectively reducing their mobility. We explore the consequences of this trapping via kinetic Monte Carlo (KMC) simulations on the oxygen vacancy (V O ) in MgGa 2 O 4 , finding that V O mobility is directly related to the degree of inversion in the system

  17. FRACTIONAL RECRYSTALLIZATION KINETICS IN DIRECTLY COLD ROLLED Al-Mg, Al-Mg-Sc AND Al-Mg-Sc-Zr ALLOY

    Directory of Open Access Journals (Sweden)

    M. S. Kaiser

    2014-12-01

    Full Text Available The evaluation of texture as a function of recrystallization has been characterized for directly cold rolled Al-6Mg, Al-6Mg-0.4Sc and Al-6Mg-0.4Sc-0.2Zr alloys. Samples were annealed isothermally at 400 °C for 1 to 240 minutes to allow recrystallization. Recrystallization kinetics of the alloys is analyzed from the micro-hardness variation. Isothermally annealed samples of aluminum alloys were also studied using JMAK type analysis to see if there exists any correlation between the methods. Recrystallization fraction behavior between two methods the scandium added alloys show the higher variation due to precipitation hardening and higher recrystallization behavior. The scandium and zirconium as a combined shows the more variation due to formation of Al3(Sc, Zr precipitate. From the microstructure it is also observed that the base Al-Mg alloy attained almost fully re-crystallized state after annealing at 400 °C for 60 minutes

  18. Nicotine chewing gum (2 mg, 4 mg) and cigarette smoking: comparative effects upon vigilance and heart rate.

    Science.gov (United States)

    Parrott, A C; Winder, G

    1989-01-01

    Sixteen male smokers, abstinent the morning before testing, were assessed under four conditions: placebo chewing gum, 2 mg nicotine chewing gum, 4 mg nicotine gum, and cigarette smoking. Placebo gum was administered in the cigarette condition, while sham smoking occurred in the gum conditions. Pre-drug administration and post-drug difference scores were calculated for each assessment measure: rapid visual information processing (RVIP), memory for new information, and heart rate. Nicotine raised heart rate in a significant monotonic dose-related manner (P less than 0.001): placebo +0.2; 2 mg gum +5.1; 4 mg gum +9.8; cigarette +17.5 bpm. Rapid visual information processing target detections were also significantly related to dose (P less than 0.01), with this increased vigilance significant under 4 mg nicotine gum and cigarette smoking. Memory task performance was not significantly affected. Self-reported feelings of alertness/energy were higher while smoking than under placebo or 4 mg gum. Complaints about the taste of the 4 mg nicotine gum were frequent.

  19. Corrosion and Discharge Behaviors of Mg-Al-Zn and Mg-Al-Zn-In Alloys as Anode Materials

    Directory of Open Access Journals (Sweden)

    Jiarun Li

    2016-03-01

    Full Text Available The Mg-6%Al-3%Zn and Mg-6%Al-3%Zn-(1%, 1.5%, 2%In alloys were prepared by melting and casting. Their microstructures were investigated via metallographic and energy-dispersive X-ray spectroscopy (EDS analysis. Moreover, hydrogen evolution and electrochemical tests were carried out in 3.5 wt% NaCl solution aiming at identifying their corrosion mechanisms and discharge behaviors. The results suggested that indium exerts an improvement on both the corrosion rate and the discharge activity of Mg-Al-Zn alloy via the effects of grain refining, β-Mg17Al12 precipitation, dissolving-reprecipitation, and self-peeling. The Mg-6%Al-3%Zn-1.5%In alloy with the highest corrosion rate at free corrosion potential did not perform desirable discharge activity indicating that the barrier effect caused by the β-Mg17Al12 phase would have been enhanced under the conditions of anodic polarization. The Mg-6%Al-3%Zn-1.0%In alloy with a relative low corrosion rate and a high discharge activity is a promising anode material for both cathodic protection and chemical power source applications.

  20. MgB{sub 2} superconductors for applications

    Energy Technology Data Exchange (ETDEWEB)

    Glowacki, B A; Majoros, M; Eisterer, M; Toenies, S; Weber, H W; Fukutomi, M; Komori, K; Togano, K

    2003-05-01

    The paper presents up to date results on MgB{sub 2} filamentary conductors and coated conductors from the point of view of their possible applications. Basic physical parameters of MgB{sub 2} compound relevant to conductor design are introduced. The correlation between the slope of the irreversibility line, critical temperature and critical current density is discussed with respect to the conductor performance and applicability. The possible origin of the observed anomalous decrease of ac susceptibility at 50 K in copper clad in situ powder-in-tube MgB{sub 2} wires is presented. Some numerical results on critical currents, thermal stability and ac losses of the MgB{sub 2} multifilamentary and coated conductors with magnetic cladding of their filaments are given.

  1. Development of Al-Mg-Li alloys for fusion reactor

    International Nuclear Information System (INIS)

    Shoji, Yoshifusa; Yoshida, Hideo; Uno, Teruo; Baba, Yoshio; Kamada, Koji.

    1985-01-01

    Aluminum-magnesium-lithium alloys featuring low residual induced radioactivity and high electrical resistivity have been developed for fusion reactor structural materials. The addition of lithium in aluminum and Al-Mg alloys markedly increases electrical resistivity and tensile strength of them. However the elongation of Al-Mg-Li alloys containing more than 2 mass% lithium are less than 10 %. The Al-4--5 mass%Mg-1 mass%Li alloys are optimum for fusion reactor materials, and exhibit high resistivity (86 nΩm: 20 %IACS), medium strength (300 MPa) and good formability (22 % elongation). The variation of electrical resistivity of Al-Li and Al-Mg-Li alloys in solid solution can be approximated by the Matthiessen's rule. (author)

  2. $^{31}$Mg $\\beta$-NMR applied in chemistry and biochemistry

    CERN Multimedia

    Magnesium ions, Mg$^{2+}$, are essential in biological systems, taking part in practically all phosphate chemistry, in photosynthesis as an integral component of chlorophyll, and they are regulated via transport through selective membrane proteins. Nonetheless, the function of magnesium ions in biochemistry is difficult to characterize, as it is practically invisible to current experimental techniques. With this proposal we aim to advance the use of $^{31}$Mg $\\beta$-NMR to liquid samples, building on the experience from the successful Letter of Intent INTC-I-088 “$\\beta$-NMR as a novel technique for biological applications”. Initially a series of experiments will be conducted aiming to characterize the coordination chemistry of Mg$^{2+}$ in ionic liquids (ILs), demonstrating that it is possible within the lifetime of the radioisotope to achieve binding of Mg$^{2+}$ to a molecule dissolved in the IL. ILs are chosen as they display a very low vapor pressure, and are thus straightforwardly compatible with t...

  3. Soluble salts addition modifies MgO hydration

    International Nuclear Information System (INIS)

    Santos, A.M.; Pandolfelli, V.C.; Salomao, R.

    2012-01-01

    Magnesium oxide (MgO) show great technological interest on refractories due to its high refractoriness, basic slag corrosion resistance and competitive cost. However, the hydration reaction of MgO produces magnesium hydroxide. This reaction generates a significant volumetric expansion that can lead to material breakdown inhibiting its use in refractory castables. This reaction can be affected by several factors such as magnesia source, purity, calcination temperature, pH, CaO/SiO 2 ratio and agitation speed. In the present work, soluble salts (CaCl 2 and MgCl 2 ) were used in MgO aqueous suspensions (caustic and sinter). The results were evaluated by means of techniques of degree of hydration (termogravimetric), Scanning electron microscopy, apparent volumetric expansion and x-ray Diffraction which showed that the degree of hydration was noticeably less to sinter aqueous and the expansive effects were less with the addition of CaCl 2 . (author)

  4. MgO monolayer epitaxy on Ni (100)

    Science.gov (United States)

    Sarpi, B.; Putero, M.; Hemeryck, A.; Vizzini, S.

    2017-11-01

    The growth of two-dimensional oxide films with accurate control of their structural and electronic properties is considered challenging for engineering nanotechnological applications. We address here the particular case of MgO ultrathin films grown on Ni (100), a system for which neither crystallization nor extended surface ordering has been established previously in the monolayer range. Using Scanning Tunneling Microscopy and Auger Electron Spectroscopy, we report on experiments showing MgO monolayer (ML) epitaxy on a ferromagnetic nickel surface, down to the limit of atomic thickness. Alternate steps of Mg ML deposition, O2 gas exposure, and ultrahigh vacuum thermal treatment enable the production of a textured film of ordered MgO nano-domains. This study could open interesting prospects for controlled epitaxy of ultrathin oxide films with a high magneto-resistance ratio on ferromagnetic substrates, enabling improvement in high-efficiency spintronics and magnetic tunnel junction devices.

  5. The investigation of radiation induced defects in MgO

    International Nuclear Information System (INIS)

    Puetz, M.

    1990-05-01

    In this paper Frenkel defects were induced in MgO by 3 MeV electrons at low temperature. These defects were investigated by measurements of the optical absorption, by investigating the lattice parameters and Huang diffuse scattering. (WL)

  6. Facile fabrication of hydrophobic surfaces on mechanically alloyed-Mg/HA/TiO{sub 2}/MgO bionanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Khalajabadi, Shahrouz Zamani [Medical Devices and Technology Group (MEDITEG), Faculty of Biosciences and Medical Engineering, Universiti Teknologi Malaysia, 81310 Johor Bahru, Johor (Malaysia); Abdul Kadir, Mohammed Rafiq, E-mail: rafiq@biomedical.utm.my [Medical Devices and Technology Group (MEDITEG), Faculty of Biosciences and Medical Engineering, Universiti Teknologi Malaysia, 81310 Johor Bahru, Johor (Malaysia); Izman, Sudin; Mohd Yusop, Mohd Zamri [Department of Materials, Manufacturing and Industrial Engineering, Faculty of Mechanical Engineering, Universiti Teknologi Malaysia, 81310 Johor Bahru, Johor (Malaysia)

    2015-01-01

    Highlights: • Mg/HA/TiO{sub 2}-based nanocomposite was produced using mechanical alloying. • The hydrophobic surface coverage was fabricated on the mechanical alloyed samples by annealing. • The morphological characteristics, phase evolution and wettability of nanocomposites and the hydrophobic surface coverage were investigated. • The activation energies and reaction kinetic of the powder mixture of nanocomposites were calculated. - Abstract: The effect of mechanical alloying and post-annealing on the phase evolution, microstructure, wettability and thermal stability of Mg–HA–TiO{sub 2}–MgO composites was investigated in this study. Phase evolution and microstructure analysis were performed using X-ray diffraction, field-emission scanning electron microscopy, transmission electron microscopy and atomic force microscopy, as well as the wettability determined by contact angle measurements with SBF. The 16-h mechanical alloying resulted in the formation of MgTiO{sub 3}, CaTiO{sub 3}, Mg{sub 3}(PO{sub 4}){sub 2} and Mg(OH){sub 2} phases and a decrease in wettability of the nanocomposites. A hydrophobic film with hierarchical structures comprising nanoflakes of MgTiO{sub 3}, nano-cuboids of CaTiO{sub 3}, microspheres of Mg{sub 3}(PO{sub 4}){sub 2} and Mg(OH){sub 2} was successfully constructed on the surface of the Mg-based nanocomposites substrates as a result of the post-annealing process. After 1-h annealing at 630 °C, the synthesized hydrophobic surface on the nanocomposite substrates decreased the wettability, as the 8-h-mechanically alloyed samples exhibited a contact angle close to 93°. The formation activation energies and reaction kinetics of the powder mixture were investigated using differential thermal analysis and thermal gravimetric analysis. The released heat, weight loss percentage and reaction kinetics increased, while the formation activation energies of the exothermic reactions decreased following an increase in the milling time.

  7. Pseudopotential approach to superconductivity in MgB2

    International Nuclear Information System (INIS)

    Sharma, K.S.; Bhargava, Nidhi; Jain, Ritu; Goyal, Varsha; Sharma, Ritu; Sharma, Smita

    2010-01-01

    Superconductivity in MgB 2 has been re-examined in BCS-Eliashberg framework by employing Mc-Millan's T c -equation and form factors of MgB 2 computed from the form factors of component metals (Model-I). The empty core model pseudopotential due to Ashcroft and random phase approximation form of dielectric screening due to Gellmann and Brueckner are used in the present work. An excellent agreement between the present values and other theoretically computed values of T c and with the relevant experimental data for MgB 2 confirms the validity of the present approach. The explicit dependence of λ and T c on the isotopic masses of Mg and B, as revealed from the present work, confirms the role of lattice vibrations in the superconducting behaviour of MgB 2 and the high value of T c in it may be attributed to the phonon mediated e-e interaction coupled with higher values of phonon frequencies due to light mass of B atoms. It has also been observed that the pseudo-atom model (Model-II) with appropriate choice of the potential parameter r c successfully explains high value of T c and isotope effect in MgB 2 , confirming the prominent role played by electron-phonon interaction in the high-T c superconductivity observed in MgB 2 . The isotope effect exponent α-values obtained from the two models are in complete agreement with each other and the present value α = 0.46 is also much closer to the BCS value of 0.5. Interaction strength N 0 V values obtained from the two models are also in perfect agreement with each other and the present value N 0 V = 0.48 suggests that MgB 2 is a strong coupling superconductor. (author)

  8. The Abundance of Mg in the Interstellar Medium

    Science.gov (United States)

    Fitzpatrick, Edward L.

    1997-06-01

    An empirical determination of the f-values of the far-UV Mg II λλ1239, 1240 lines is reported. The strong near-UV Mg II λλ2796, 2803 lines are generally highly saturated along most interstellar sight lines outside the local interstellar medium (ISM) and usually yield extremely uncertain estimates of Mg+ column densities in interstellar gas. Since Mg+ is the dominant form of Mg in the neutral ISM, and since Mg is expected to be a significant constituent of interstellar dust grains, the far-UV lines are critical for assessing the role of this important element in the ISM. This study consists of complete component analyses of the absorption along the lines of sight toward HD 93521 in the Galactic halo and ξ Persei and ζ Ophiuchi in the Galactic disk, including all four UV Mg+ lines and numerous other transitions. The three analyses yield consistent determinations of the λλ1239, 1240 f-values, with weighted means of (6.4 +/- 0.4) × 10-4 and (3.2 +/- 0.2) × 10-4, respectively. These results are a factor of ~2.4 larger than a commonly used theoretical estimate, and a factor of ~2 smaller than a recently suggested empirical revision. The effects of this result on gas- and dust-phase abundance measurements of Mg are discussed. Based on observations with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, under NASA contract NAS5-2655. This Letter is dedicated to the memory of Professor Lyman Spitzer Jr. He was a great guy.

  9. Mg and Sr in Arctic echinoderm calcite: Nature or nurture?

    Science.gov (United States)

    Iglikowska, A.; Borszcz, T.; Drewnik, A.; Grabowska, M.; Humphreys-Williams, E.; Kędra, M.; Krzemińska, M.; Piwoni-Piórewicz, A.; Kukliński, P.

    2018-04-01

    The Mg/Ca and Sr/Ca ratios in echinoderm skeletal calcite are used as a proxy for Phanerozoic seawater changes, since the skeletal concentrations are, to some extent, controlled by environmental factors. However, it remains unclear how the influence of environmental factors is modified by vital effects, especially in polar waters. Therefore, the goal of this study was to compare the ratios of Mg/Ca and Sr/Ca among the skeletal parts of 10 common Arctic echinoderm species belonging to three classes Echinoidea, Asteroidea and Ophiuroidea that contribute substantially to the carbon cycle in the Arctic benthic system. Significant differences were recorded in echinoid skeletal element concentrations among specific skeletal parts. The lowest Mg/Ca and Sr/Ca ratios were detected in the spines (mean Mg/Ca 37.5 ± 8.8 SD; Sr/Ca 1.8 ± 0.1). The components of the Aristotle's lantern (epiphyses, pyramids and rotulas) were characterised by the highest Mg levels (Mg/Ca 79.9 ± 6.0; 75.2 ± 9.1; 60.1 ± 3.8, respectively). It is likely that mouth parts experience greater mechanical pressure compared to other body parts, and the higher content of Mg in the Aristotle's lantern contributes to its robustness. We did not find any distinctive trends in the distribution of skeletal elements in the asteroid and ophiuroid skeletal parts. The heterogeneous concentrations of Mg and Sr in different skeleton parts of the echinoids suggest possible physiological regulation of the chemical composition rather than the composition only being influenced by the environment. We cannot recommend echinoderm skeletons as reliable indicators in palaeoenvironmental reconstructions due to the possible biological control of skeletal chemistry, which may interfere with the effect of environmental variables.

  10. A metastable Mg11Sm phase obtained by rapid solidification

    International Nuclear Information System (INIS)

    Budurov, S.

    1993-01-01

    Molten Mg-Sm alloys with a Sm concentration of 4.93, 6.86, and 8.35 at.% were rapidly soldified with the aid of a shock wave gun device. Investigations of the obtained splats were performed with the aid of DSC, X-ray analysis, and metallography. Rapid soldification of the eutectic MgSm 8.35 alloy forms a new Im3m-type phase. (orig.)

  11. Strength of FePd/MgO and FePt/MgO interfaces from first principles

    Science.gov (United States)

    Černý, M.

    2018-04-01

    Cleavage characteristics such as the cleavage energy and the cleavage stress of FePd/MgO and FePt/MgO interfaces are computed from first principles. Considering several possible cleavage planes, the weakest link in these systems is found as the plane with the lowest cleavage stress. This weakest plane is identified in both systems with the interface plane, where the cohesion is reduced by 30% compared to the MgO bulk. Two distinct models of tensile test are employed to verify the results and convergence of computed values with respect to size of the simulation cell is discussed.

  12. A double-blind study comparing ibuprofen 1800 mg or 2400 mg daily and placebo in sports injuries.

    Science.gov (United States)

    Hutson, M A

    1986-01-01

    In a double-blind, placebo-controlled study of forty-six patients with acute ligamentous damage of the knee, ibuprofen in dosages 1800 mg and 2400 mg produced significant improvements in joint mobility, weight bearing ability and match fitness. Joint effusion, pain on stress and pain severity was significantly improved by all three treatments. Only two patients reported side-effects (one while taking placebo and one taking ibuprofen 2400 mg). The study confirmed the efficacy and excellent tolerance to ibuprofen in patients with sports injuries to the knee.

  13. Hydrogen incorporation in high hole density GaN:Mg

    Science.gov (United States)

    Zvanut, M. E.; Uprety, Y.; Dashdorj, J.; Moseley, M.; Doolittle, W. Alan

    2011-03-01

    We investigate hydrogen passivation in heavily doped p-type GaN using electron paramagnetic resonance (EPR) spectroscopy. Samples include both conventionally grown GaN (1019 cm-3 Mg, 1017 cm-3 holes) and films grown by metal modulation epitaxy (MME), which yielded higher Mg (1- 4 x 1020 cm-3) and hole (1- 40 x 1018 cm-3) densities than found in conventionally grown GaN. The Mg acceptor signal is monitored throughout 30 minute annealing steps in N2 :H2 (92%:7%)) and subsequently pure N2 . N2 :H2 heat treatments of the lower hole density films begin to reduce the Mg EPR intensity at 750 o C, but quench the signal in high hole density films at 600 o C. Revival of the signal by subsequent N2 annealing occurs at 800 o C for the low hole density material and 600 o C in MME GaN. The present work highlights chemical differences between heavily Mg doped and lower doped films; however, it is unclear whether the difference is due to changes in hydrogen-Mg complex formation or hydrogen diffusion. The work at UAB is supported by the NSF.

  14. In vitro degradation of pure Mg in response to glucose

    Science.gov (United States)

    Zeng, Rong-Chang; Li, Xiao-Ting; Li, Shuo-Qi; Zhang, Fen; Han, En-Hou

    2015-08-01

    Magnesium and its alloys are promising biodegradable biomaterials but are still challenging to be used in person with high levels of blood glucose or diabetes. To date, the influence of glucose on magnesium degradation has not yet been elucidated, this issue requires more attention. Herein, we present pure Mg exhibiting different corrosion responses to saline and Hank’s solutions with different glucose contents, and the degradation mechanism of pure Mg in the saline solution with glucose in comparison with mannitol as a control. On one hand, the corrosion rate of pure Mg increases with the glucose concentration in saline solutions. Glucose rapidly transforms into gluconic acid, which attacks the oxides of the metal and decreases the pH of the solution; it also promotes the absorption of chloride ions on the Mg surface and consequently accelerates corrosion. On the other hand, better corrosion resistance is obtained with increasing glucose content in Hank’s solution due to the fact that glucose coordinates Ca2+ ions in Hank’s solution and thus improves the formation of Ca-P compounds on the pure Mg surface. This finding will open up new avenues for research on the biodegradation of bio-Mg materials in general, which could yield many new and interesting results.

  15. Behavior of lambda 2800 Mg II in stellar spectra

    International Nuclear Information System (INIS)

    Gurzadyan, G.A.

    1975-01-01

    The results of measurements of the equivalent widths of the resonance doublet of ionized magnesium lambda 2800 Mg II in the spectra of 51 relatively faint stars, up to 10/sup m/, of the spectral classes B1-K5 are presented. The observed material has been obtained by means of the space observatory ''Orion-2''. Some regularities in the behavior of lambda 2800 Mg II in stellar spectra have been revealed: wide and deep depression of the continuous spectra at 2800 A in F-G type stars; the presence of the doublet lambda 2800 Mg II in the form of weak emission in the spectra of cold stars (K2-K5); the presence both of the multiplet lambda 3080 Ti II and the doublet lambda 2800 Mg II simultaneously either in emission--in the late-type stars--or in absorption in earlier types; the existence of combined profiles of lambda 2800 Mg II, i.e., a wide absorption line with a weak emission in the center, in stars of the transitional class (G5-K0), etc. A well-defined empirical relationship between the equivalent width of lambda 2800 Mg II and the spectral class of the star has been established (Fig. 8). (U.S.)

  16. Loss of Endothelial Barrier in Marfan Mice (mgR/mgR Results in Severe Inflammation after Adenoviral Gene Therapy.

    Directory of Open Access Journals (Sweden)

    Philipp Christian Seppelt

    Full Text Available Marfan syndrome is an autosomal dominant inherited disorder of connective tissue. The vascular complications of Marfan syndrome have the biggest impact on life expectancy. The aorta of Marfan patients reveals degradation of elastin layers caused by increased proteolytic activity of matrix metalloproteinases (MMPs. In this study we performed adenoviral gene transfer of human tissue inhibitor of matrix metalloproteinases-1 (hTIMP-1 in aortic grafts of fibrillin-1 deficient Marfan mice (mgR/mgR in order to reduce elastolysis.We performed heterotopic infrarenal transplantation of the thoracic aorta in female mice (n = 7 per group. Before implantation, mgR/mgR and wild-type aortas (WT, C57BL/6 were transduced ex vivo with an adenoviral vector coding for human TIMP-1 (Ad.hTIMP-1 or β-galactosidase (Ad.β-Gal. As control mgR/mgR and wild-type aortas received no gene therapy. Thirty days after surgery, overexpression of the transgene was assessed by immunohistochemistry (IHC and collagen in situ zymography. Histologic staining was performed to investigate inflammation, the neointimal index (NI, and elastin breaks. Endothelial barrier function of native not virus-exposed aortas was evaluated by perfusion of fluorescent albumin and examinations of virus-exposed tissue were performed by transmission electron microscopy (TEM.IHC and ISZ revealed sufficient expression of the transgene. Severe cellular inflammation and intima hyperplasia were seen only in adenovirus treated mgR/mgR aortas (Ad.β-Gal, Ad.hTIMP-1 NI: 0.23; 0.43, but not in native and Ad.hTIMP-1 treated WT (NI: 0.01; 0.00. Compared to native mgR/mgR and Ad.hTIMP-1 treated WT aorta, the NI is highly significant greater in Ad.hTIMP-1 transduced mgR/mgR aorta (p = 0.001; p = 0.001. As expected, untreated Marfan grafts showed significant more elastolysis compared to WT (p = 0.001. However, elastolysis in Marfan aortas was not reduced by adenoviral overexpression of hTIMP-1 (compared to untreated

  17. MgB2 and Mg1-xAlxB2 single crystals: high pressure growth and physical properties

    International Nuclear Information System (INIS)

    Karpinski, J.; Kazakov, S.M.; Jun, J.; Zhigadlo, N.D.; Angst, M.; Puzniak, R.; Wisniewski, A.

    2004-01-01

    Single crystals of MgB 2 have been grown with a high pressure cubic anvil technique. They grow via the peritectic decomposition of the MgNB 9 ternary nitride. The crystals are of a size up to 2 x 1 x 0.1 mm 3 with a weight up to 230 μg. Typically they have transition temperatures between 38 and 38.6 K with a width of 0.3-0.5 K. Investigations of the P-T phase diagram prove that the MgB 2 phase is stable at least up to 2190 deg. C at high hydrostatic pressure in the presence of Mg vapor under high pressure. Substitution of aluminum for magnesium in single crystals leads to stepwise decrease of T c . This indicates a possible appearance of superstructures or phases with different T c 's. The upper critical field decreases with Al doping

  18. First-principles study of the (0001)-MgB2 surface finished in Mg and B

    International Nuclear Information System (INIS)

    Segura, Sully; Martínez, Jairo Arbey Rodríguez; Moreno-Armenta, María Guadalupe

    2014-01-01

    We present a study based on Density Functional Theory (DFT) of the volume and two surfaces (0001) of MgB 2 , one of them terminated in Mg and the other one terminated in B. Each one of the surface was relaxed and their electronic properties were determined. From calculation of the enthalpy of formation we found that the Mg-terminated surface is energetically favored. The bands seem to present a formation similar to the Dirac's cone as that are presented in graphene, but in MgB 2 is above of the Fermi level. In the three cases, volume and the two surfaces, the behaviour is boron-metallic, because there are strong presence of B orbital's in the neighborhood of the Ferm level

  19. Density functional theory (DFT) study on the hydrolysis behavior of degradable Mg/Mg alloys for biomedical applications

    Science.gov (United States)

    Nezafati, Marjan

    Magnesium-based (Mg and/or Mg alloys) materials possess many advantageous physicochemical/biological characteristics such as good biocompatibility and similarity of the mechanical properties to the human bone tissue, which renders this material a promising candidate for the biomedical and implant applications. One of the most attractive features of Mg-based materials is the degradability in the physiological environment. With the burst of research on the biodegradable materials for the healthcare device applications, Mg and its alloys attracted a strong attention in the bioengineering field in recent years. However, the major limitation of applying Mg-based materials to biomedical applications is the fast degradation/corrosion rate with regards to the healing process time-span. In the present thesis, an atomistic model employing the density-functional theory (DFT) has been developed to study the hydrolysis process by understanding the influences of commonly used alloying elements (zinc (Zn), calcium (Ca), aluminum (Al), and yttrium (Y)) and the crystallographic orientation of the dissolution surfaces (basal (0001), prism (1010), and pyramidal (1011) planes) on the corrosion behavior. These parameters are known to strongly impact the initial hydrolysis phenomena of Mg-based materials. To develop the atomistic computational model, we have implemented the Dmol3 software package in conjunction with PBE (Perdew, Burke and Ernzerhof) correlation energy functional in the GGA (generalized gradient approximation) scheme. Throughout the thesis, we performed three sets of calculations, i) surface energy, ii) dissolution potential, and iii) water adsorption computations, to examine the hydrolysis mechanism and the subsequent corrosion/degradation of Mg/Mg alloys. The total energy changes of various Mg-based systems in different conditions for these surface energies, dissolution behavior, and tendency of the system for adsorbing the water molecule were quantified. The results

  20. Phototransfered thermoluminescence for dose reassessment in LiF:mg,ti , LiF: mg,Cu,p TL detectors

    International Nuclear Information System (INIS)

    Rodriguez Otazo, M.; Baly, L.

    2001-01-01

    Phototransfered Thermoluminescence (PTTL) from LiF:Mg,Ti (TLD-100) and LiF: Mg,Cu,P (GR-200) was studied at different conditions using different sources of UV light for dose reassessment purposes. The TL dosimeters were irradiated with 137Cs in the range 2 mGy to 100 mGy. The convenience of using PTTL for dose reassessment was analyzed

  1. Corrosion inhibition of powder metallurgy Mg by fluoride treatments.

    Science.gov (United States)

    Pereda, M D; Alonso, C; Burgos-Asperilla, L; del Valle, J A; Ruano, O A; Perez, P; Fernández Lorenzo de Mele, M A

    2010-05-01

    Pure Mg has been proposed as a potential degradable biomaterial to avoid both the disadvantages of non-degradable internal fixation implants and the use of alloying elements that may be toxic. However, it shows excessively high corrosion rate and insufficient yield strength. The effects of reinforcing Mg by a powder metallurgy (PM) route and the application of biocompatible corrosion inhibitors (immersion in 0.1 and 1M KF solution treatments, 0.1M FST and 1M FST, respectively) were analyzed in order to improve Mg mechanical and corrosion resistance, respectively. Open circuit potential measurements, polarization techniques (PT), scanning electrochemical microscopy (SECM) and electrochemical impedance spectroscopy (EIS) were performed to evaluate its corrosion behavior. SECM showed that the local current of attacked areas decreased during the F(-) treatments. The corrosion inhibitory action of 0.1M FST and 1M FST in phosphate buffered solution was assessed by PT and EIS. Under the experimental conditions assayed, 0.1M FST revealed better performance. X-ray photoelectron spectroscopy, energy dispersive X-ray and X-ray diffraction analyses of Mg(PM) with 0.1M FST showed the presence of KMgF(3) crystals on the surface while a MgF(2) film was detected for 1M FST. After fluoride inhibition treatments, promising results were observed for Mg(PM) as degradable metallic biomaterial due to its higher yield strength and lower initial corrosion rate than untreated Mg, as well as a progressive loss of the protective characteristics of the F(-)-containing film which ensures the gradual degradation process. Copyright (c) 2009 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  2. Corrosion behaviour of Mg-Cu and Mg-Mo composites in 3.5% NaCl

    International Nuclear Information System (INIS)

    Budruk Abhijeet, S.; Balasubramaniam, R.; Gupta, M.

    2008-01-01

    The corrosion behaviour of pure magnesium, Mg-Cu (0.3, 0.6, and 1 vol.%) and Mg-Mo (0.1, 0.3, and 0.6 vol.%) composites has been studied in 3.5% NaCl solution by weight loss and polarisation methods. Corrosion rates determined by weight loss method were considerably higher than that determined by polarisation method. The corrosion rate increased with increasing volume fraction of reinforcement in Mg-Cu and Mg-Mo composites. At the same volume fraction of reinforcement, molybdenum reinforced composite corroded faster than copper reinforced composite. The galvanic current density between Mg-Cu and Mg-Mo couples has been experimentally measured using zero resistance ammeter technique. The experimentally observed galvanic current densities were in close agreement with those obtained using mixed potential theory analysis. SEM observation of corroded samples confirmed microgalvanic activity at the matrix/reinforcement interfaces. The poor corrosion resistance of composites has been attributed to microgalvanic effects between the matrix and reinforcements and inferior quality of surface films

  3. Experimental investigation and thermodynamic calculation of the Fe-Mg-Mn and Fe-Mg-Ni systems

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Peisheng; Zhao, Jingrui; Xu, Honghui; Liu, Shuhong; Ouyang, Hongwu [Central South Univ., Hunan (China). State Key Lab. of Powder Metallurgy; Du, Yong [Central South Univ., Hunan (China). State Key Lab. of Powder Metallurgy; Harbin Institute of Technology (China). State Key Lab. of Advanced Welding Production Technology; Gang, Tie; Fen, Jicai [Harbin Institute of Technology (China). State Key Lab. of Advanced Welding Production Technology; Zhang, Lijun [Central South Univ., Hunan (China). State Key Lab. of Powder Metallurgy; Bochum Univ. (Germany). ICAMS Inst.; He, Cuiyun [Guangxi Univ. (China). College of Physical Science and Technology

    2011-01-15

    Based on the thermodynamic calculations extrapolated from the corresponding binary sub-systems, four decisive alloys in the Fe-Mg-Mn system and three in the Fe-Mg-Ni system were selected and prepared using a powder metallurgy method to measure the isothermal sections at 500 C in both systems. The prepared samples were annealed at 500 C, and then subjected to X-ray diffraction, optical microscopy, scanning electron microscopy with energy-dispersive X-ray spectrometry as well as electron probe microanalysis. Taking into account the presently obtained experimental data and the experimental data available in the literature, thermodynamic modeling was performed for the above systems. It was found that a direct extrapolation from the corresponding three binary systems can well reproduce all the experimental data in the Fe-Mg-Mn system, while two thermodynamic parameters are needed in the Fe-Mg-Ni system to fit all the experimental data. The liquidus projections and reaction schemes for the Fe-Mg-Mn and Fe-Mg-Ni systems are also presented. (orig.)

  4. Comparison of effects of ATP-MgCl2 and adenosine-MgCl2 on renal function following ischemia

    International Nuclear Information System (INIS)

    Sumpio, B.E.; Hull, M.J.; Baue, A.E.; Chaudry, I.H.

    1987-01-01

    ATO-MgCl 2 administration had been shown to accelerate the recovery of renal function following warm ischemia. However, since the major breakdown product of ATP is adenosine, the relative contribution of ATP vs. adenosine in improving renal function following ischemia remains to be determined. To study this, kidneys were subjected to 45 min of normothermic ischemia and then perfused at 100 mmHg with oxygenated Krebs-HCO 3 buffer containing albumin, [ 3 H]inulin, substrates, and either 0.3 mM ATP-MgCl 2 or adenosine-MgCl 2 for 110 min. Perfusate and timed urine samples were collected and analyzed for radioactivity and [Na + ]. The functional parameters indicated that although adenosine-MgCl 2 treatment provided a transient improvement, it failed to provided a sustained improvement in renal function or attain control valued compared with ATP-MgCl 2 treatment. Thus, the salutary effects of ATP-MgCl 2 following warm ischemia in the kidney are not mediated by adenosine

  5. Influences of the quantity of Mg2Sn phase on the corrosion behavior of Mg-7Sn magnesium alloy

    International Nuclear Information System (INIS)

    Liu Xianbin; Shan Dayong; Song Yingwei; Chen Rongshi; Han Enhou

    2011-01-01

    The influence of the quantity of the Mg 2 Sn phase on the corrosion behavior of different solution temperature treated Mg-7Sn magnesium alloy has been investigated by electrochemical measurements, scanning electron microscope (SEM) observation, X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) analysis. With the increase of solution temperature, the quantity of Mg 2 Sn phase decreased and the tin concentration of matrix increased. The dissolved tin in Mg matrix took part in the film formation and the constituent of film was magnesium oxide and stannic oxide. The corrosion mode and corrosion rate were associated with the quantity of Mg 2 Sn phases and tin concentration of the matrix. If most of tin was present as Mg 2 Sn, the corrosion mode was pitting corrosion and it accelerated the corrosion rate. If most of tin was dissolved in matrix, the corrosion mode was filiform corrosion and it decreased the corrosion rate. The experiment evidences demonstrated that the corrosion resistance can be improved by increasing the tin concentration of matrix and the lowest corrosion rate was observed for sample solution treated at 540 o C.

  6. Formation of Al3Ti/Mg composite by powder metallurgy of Mg-Al-Ti system.

    Science.gov (United States)

    Yang, Zi R; Qi Wang, Shu; Cui, Xiang H; Zhao, Yu T; Gao, Ming J; Wei, Min X

    2008-07-01

    An in situ titanium trialuminide (Al 3 Ti)-particle-reinforced magnesium matrix composite has been successfully fabricated by the powder metallurgy of a Mg-Al-Ti system. The reaction processes and formation mechanism for synthesizing the composite were studied by differential scanning calorimetry (DSC), x-ray diffractometry (XRD), scanning electron microscopy (SEM) and energy-dispersive x-ray spectroscopy (EDS). Al 3 Ti particles are found to be synthesized in situ in the Mg alloy matrix. During the reaction sintering of the Mg-Al-Ti system, Al 3 Ti particles are formed through the reaction of liquid Al with as-dissolved Ti around the Ti particles. The formed intermetallic particles accumulate at the original sites of the Ti particles. As sintering time increases, the accumulated intermetallic particles disperse and reach a relatively homogeneous distribution in the matrix. It is found that the reaction process of the Mg-Al-Ti system is almost the same as that of the Al-Ti system. Mg also acts as a catalytic agent and a diluent in the reactions and shifts the reactions of Al and Ti to lower temperatures. An additional amount of Al is required for eliminating residual Ti and solid-solution strengthening of the Mg matrix.

  7. The Visibility of Scholarly Knowledge: Awareness for Open Access in Hacettepe University Bilimsel Bilginin Görünürlüğü: Hacettepe Üniversitesi’nde Açık Erişim Farkındalığı

    Directory of Open Access Journals (Sweden)

    Korhan Levent Ertürk

    2010-03-01

    Full Text Available The scholars begin to place their works into the open repositories or open access journals as well as their personal web sites. In the international arena, the open repositories contain a total of 14,000 Turkey-based scholarly contents. The focus of this study is to determine the level of awareness for open access concept of scholars in Hacettepe University. An electronic questionnaire was conducted to scholars. The data were collected through questionnaire from full time academic staff member in Hacettepe University. It was found that 50% of scholars are aware of the open access concept and 92% of the scholars are willing to place their works into the institutional repository of their university. According to questionnaire study result, different types of works such as articles and assertions can be placed in the institutional open repositories in Turkey and their functionality can be increased in a short time. Bilimsel iletişimin en önemli paydaşı olan bilim insanları, bilimsel bilgilerinin görünürlüğünü artırabilmek için bilimsel eserlerini Web sayfalarında ve/veya açık erişim arşivlerinde depolamaya ya da açık erişim dergilerinde yayınlamaya başlamışlardır. Uluslararası açık erişim arşivlerinde yaklaşık 14 bin Türkiye kaynaklı bilimsel içerik bulunmaktadır. Bu çalışma Hacettepe Üniversitesi’ndeki bilim insanlarının açık erişim farkındalığını belirlemek, kurumsal açık arşivlerin etkin kullanımını konusundaki görüşlerini ortaya çıkarmak amacıyla yapılmıştır. Veriler, Hacettepe Üniversitesi’nde tam zamanlı çalışan öğretim üyelerinden elektronik anket yoluyla elde edilmiştir. Bulgulara göre öğretim üyelerinin en azından yarısının (%50 açık erişim farkındalığına sahip olduğu tespit edilmiştir. Farkındalığı olan öğretim üyeleri yüksek bir çoğunlukla (%92 yayınlarının kendi üniversitelerinde yapılandırılabilecek kurumsal açık ar

  8. Catalytic effect of Ni, Mg2Ni and Mg2NiH4 upon hydrogen desorption from MgH2

    Czech Academy of Sciences Publication Activity Database

    Čermák, Jiří; David, Bohumil

    2011-01-01

    Roč. 36, č. 21 (2011), s. 13614-13620 ISSN 0360-3199 R&D Projects: GA ČR GA106/09/0814; GA ČR(CZ) GAP108/11/0148 Institutional research plan: CEZ:AV0Z20410507 Keywords : MgH2 * Hydrogen storage * Hydrogen desorption * Catalysis Subject RIV: JG - Metallurgy Impact factor: 4.054, year: 2011

  9. Photoneutron strengths in 26Mg at energies of astrophysical interest

    Science.gov (United States)

    deBoer, R. J.; Best, A.; Görres, J.; Smith, K.; Tan, W.; Wiescher, M.; Raut, R.; Rusev, G.; Tonchev, A. P.; Tornow, W.

    2014-05-01

    Background: The 22Ne(α,n)25Mg reaction is an important source of neutrons for s-process nucleosynthesis. The neutron production from the reaction is quite sensitive to the low-energy cross section, which is dominated by narrow resonances. The high level density of the 26Mg compound nucleus above the α separation energy prevents simple extrapolations from higher energy and the high Coulomb barrier makes the direct measurements extremely difficult. For this reason, indirect methods must be employed to study the level properties of 26Mg. Purpose: The current measurement utilizes the reaction 26Mg(γ,n)25Mg to probe the level structure of the 26Mg compound nucleus from the neutron-separation energy at 11.093 MeV up to Ex≈ 12 MeV. Methods: The High-Intensity γ-ray Source of the Triangle Universities Nuclear Laboratory was used to bombard a ˜16 g sample of enriched 26Mg oxide and the resulting decay neutrons were detected with an array of nine liquid scintillator detectors. Neutron time-of-flight peaks with corresponding energies as low as ˜50 keV were detected. An efficiency measurement of the detectors was made at the University of Notre Dame's nuclear science laboratory to energies as low as 45 keV. Results: Five resonances were observed at Eγ = 11.150, 11.289, 11.329, 11.506, and 11.749 MeV and their strengths have been extracted. Conclusion:. The resulting strengths at Eγ = 11.289, 11.329, 11.506, and 11.749 MeV are in good agreement with previous measurements. The strength of the resonance at Eγ = 11.150 MeV is somewhat lower than previously measured but is in reasonable agreement when systematic uncertainties are considered. The results are also consistent with those of 25Mg(n,γ)26Mg studies where a comparison shows that many of the resonances observed here are the result of multiple unresolved narrow resonances.

  10. Ab initio calculations of half-metallic ferromagnetism in Cr-doped MgSe and MgTe semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Noor, N.A. [Department of Physics, University of the Punjab, Quaid-e-Azam Campus, 54590 Lahore (Pakistan); Alay-e-Abbas, S.M. [Department of Physics, University of Sargodha, Sargodha 40100 (Pakistan); Department of Physics, GC University Faisalabad, Allama Iqbal Road, Faisalabad 38000 (Pakistan); Sohaib, M.U. [Lahore Development Authority, 54590 Lahore (Pakistan); Ghulam Abbas, S.M. [Department of Chemistry, University of Agriculture, Faisalabad 38040 (Pakistan); Shaukat, A., E-mail: schaukat@gmail.com [Department of Physics, University of Sargodha, Sargodha 40100 (Pakistan)

    2015-01-15

    The full-potential linear-augmented-plane-waves plus local-orbitals (FP-LAPW+lo) method has been employed for investigation of half-metallic ferromagnetism in Cr-doped ordered zinc-blende MgSe and MgTe semiconductors. Calculations of exchange and correlation (XC) effects have been carried out using generalized gradient approximation (GGA) and orbital independent modified Becke–Johnson potential coupled with local (spin) density approximation (mBJLDA). The thermodynamic stability of the compounds and their preferred magnetic orders have been analyzed in terms of the heat of formation and minimum total energy difference in ferromagnetic (FM) and anti-ferromagnetic (AFM) ordering, respectively. Calculated electronic properties reveal that the Cr-doping induces ferromagnetism in MgSe and MgTe which gives rise to a half-metallic (HM) gap at Fermi level (E{sub F}). Further, the electronic band structure is discussed in terms of s (p)–d exchange constants that are consistent with typical magneto-optical experiment and the behavior of charge spin densities is presented for understanding the bonding nature. Our results demonstrate that the higher effective potential for the spin-down case is responsible for p–d exchange splitting. Total magnetic moment (mainly due to Cr-d states) of these compounds is 4µ{sub B}. Importantly, the electronic properties and HM gap obtained using mBJLDA show remarkable improvement as compared to the results obtained using standard GGA functional. - Highlights: • Spin effect theoretical study on Cr-doped MgSe and MgTe is performed. • Half-metallic ferromagnetism in Cr{sub x}Mg{sub 1−x}Se and Cr{sub x}Mg{sub 1−x}Te is established. • Results of WC-GGA and mBJLDA are compared for performance. • HM gaps for Cr{sub x}Mg{sub 1−x}Se and Cr{sub x}Mg{sub 1−x}Te show nonlinear variation with x. • Important values of exchange splitting/constants and moments are reported.

  11. Dry cryomagnetic system with MgB2 coil

    Science.gov (United States)

    Abin, D. A.; Mineev, N. A.; Osipov, M. A.; Pokrovskii, S. V.; Rudnev, I. A.

    2017-12-01

    MgB2 may be the future superconducting wire material for industrial magnets due to it’s higher operation temperature and potentially lower cost than low temperature superconductors (LTS) have. We designed a compact cryomagnetic system with the use of MgB2. The possibility of creating a magnet with a central field of 5 T from a commercial MgB2 wire by the “react and wound” method was investigated. The magnetic system is cooled by a cryocooler through a copper bus. The magnet has a warm bore diameter of 4 cm. The design of a magnet consisting of three concentric solenoids is proposed: an internal one of high-temperature superconductor (HTS), an average of MgB2, and an external of NbTi. The operating current of the system is 100 A. Two pairs of current leads are used. A separate pair of current leads for power supplying NbTi coil allows testing of MgB2 and HTS coils in an external field. The load curves for each of the magnets are calculated.

  12. Multifunctional MgO Layer in Perovskite Solar Cells.

    Science.gov (United States)

    Guo, Xudong; Dong, Haopeng; Li, Wenzhe; Li, Nan; Wang, Liduo

    2015-06-08

    A multifunctional magnesium oxide (MgO) layer was successfully introduced into perovskite solar cells (PSCs) to enhance their performance. MgO was coated onto the surface of mesoporous TiO(2) by the decomposition of magnesium acetate and, therefore, could block contact between the perovskite and TiO(2). X-ray photoelectron spectroscopy and infrared spectroscopy showed that the amount of H(2)O/hydroxyl absorbed on the TiO(2) decreased after MgO modification. The UV/Vis absorption spectra of the perovskite with MgO modification revealed an enhanced photoelectric performance compared with that of unmodified perovskite after UV illumination. In addition to the photocurrent, the photovoltage and fill factor also showed an enhancement after modification, which resulted in an increase in the overall efficiency of the cell from 9.6 to 13.9 %. Electrochemical impedance spectroscopy (EIS) confirmed that MgO acts as an insulating layer to reduce charge recombination. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Formation of MgZnO alloy under thermodynamic conditions

    Energy Technology Data Exchange (ETDEWEB)

    Markevich, I.V.; Stara, T.R., E-mail: stara_t@ukr.net; Kuchuk, A.V.; Polishchuk, Yu.O.; Kladko, V.P.

    2014-11-15

    Mg{sub x}Zn{sub 1−x}O ceramics with x=0.10, 0.15, 0.20, 0.25 and 0.30 were sintered at T{sub s}=700–1250 °C. Photoluminescence (PL) and PL excitation (PLE) spectra as well as X-ray diffraction patterns were measured at 293 K. Bandgap width was evaluated from the position of PLE peak. Non-monotonous dependence of PLE peak position on T{sub s} was observed for all used x. This effect was concluded to be caused by the formation of cubic phase side by side with hexagonal one and the enhancement of this process with increasing T{sub s}, which resulted in the decrease of Mg content in the hexagonal phase at T{sub s}>1000 °C. Temperature range of 1000–1050 °C was found to be the optimum one for the formation of hexagonal MgZnO alloy at used x. It was shown that x=0.20 was the solubility limit of MgO in hexagonal Mg{sub x}Zn{sub 1−x}O ceramics.

  14. Use of porous MgO in pyrochemical applications

    International Nuclear Information System (INIS)

    Maiya, P.S.; Sweeney, S.M.; Carroll, L.A.; Dusek, J.T.

    1994-11-01

    Pyrochemical methods for the extraction of transuranic elements from light water reactor spent fuel require a reduction step in which the oxide fuel is reduced to metals by Li in molten LiCl. The Li 2 O formed is electrolytically reduced to metal in a cell that uses a carbon (or inert) anode and a Li cathode to recycle the salt and minimize the waste. Use of a carbon anode causes carbon dust that interferes with the process. Moreover, current efficiency is reduced as a result of oxidation of Li to Li 2 O by CO 2 . A porous MgO shroud around the anode was found to obviate these problems. Porous MgO crucibles and rectangular bar specimens were fabricated from MgO powders (electrically fused MgO, reagent grade MgO were mixed in appropriate combinations with a binder and lubricant). Particle size, force applied to the powders during cold pressing, and sintering temperature were varied to achieve a total porosity of >45% (mostly open porosity) and to control pore size and pore distribution. Mercury intrusion porosimetry was used to determine the pore size and pore size distribution. Flexural strength is observed to be proportional to the square root of pore size, which is consistent with fracture mechanics

  15. Magnesium balances and 28Mg studies in man

    International Nuclear Information System (INIS)

    Spencer, H.; Schwartz, R.; Osis, D.

    1988-01-01

    The intestinal absorption of magnesium was determined under strictly controlled dietary conditions in patients with normal renal function and also in patients with chronic renal failure. The average net absorption of magnesium of patients with normal renal function, expressed as percent of the magnesium intake, was 48.5%, while that of patients with chronic renal failure was significantly lower, 17%. Increasing the calcium intake from a low calcium intake of 200 mg/day to different higher intake levels up to 2000 mg/day did not change the magnesium balance nor the net absorption of magnesium of both types of patients. The lack of effect of the higher calcium intake on the absorption of magnesium was confirmed in 28 Mg studies in which an oral dose of 28 Mg, as the chloride, was given. The excretion of the absorbed magnesium into the intestine, the endogenous fecal magnesium, was low. Also, increasing the phosphorus intake up to 2000 mg/day in subjects with normal renal function did not affect the magnesium balance, regardless of the calcium intake

  16. Mg-MOF-74/MgF₂ Composite Coating for Improving the Properties of Magnesium Alloy Implants: Hydrophilicity and Corrosion Resistance.

    Science.gov (United States)

    Liu, Wei; Yan, Zhijie; Ma, Xiaolu; Geng, Tie; Wu, Haihong; Li, Zhongyue

    2018-03-07

    Surface modification on Mg alloys is highly promising for their application in the field of bone repair. In this study, a new metal-organic framework/MgF₂ (Mg-MOF-74/MgF₂) composite coating was prepared on the surface of AZ31B Mg alloy via pre-treatment of hydrofluoric acid and in situ hydrothermal synthesis methods. The surface topography of the composite coating is compact and homogeneous, and Mg-MOF-74 has good crystallinity. The corrosion resistance of this composite coating was investigated through Tafel polarization test and immersion test in simulated body fluid at 37 °C. It was found that Mg-MOF-74/MgF₂ composite coating significantly slowed down the corrosion rate of Mg alloy. Additionally, Mg-MOF-74/MgF₂ composite coating expresses super-hydrophilicity with the water contact angle of nearly 0°. In conclusion, on the basis of MgF₂ anticorrosive coating, the introduction of Mg-MOF-74 further improves the biological property of Mg alloys. At last, we propose that the hydrophilicity of the composite coating is mainly owing to the large number of hydroxyl groups, the high specific surface area of Mg-MOF-74, and the rough coating produced by Mg-MOF-74 particles. Hence, Mg-MOF-74 has a great advantage in enhancing the hydrophilicity of Mg alloy surface.

  17. Comparative study of 250 mg/day terbinafine and 100 mg/day itraconazole for the treatment of cutaneous sporotrichosis.

    Science.gov (United States)

    Francesconi, Glaucia; Francesconi do Valle, Antonio Carlos; Passos, Sonia Lambert; de Lima Barros, Mônica Bastos; de Almeida Paes, Rodrigo; Curi, André Luiz Land; Liporage, José; Porto, Cássio Ferreira; Galhardo, Maria Clara Gutierrez

    2011-05-01

    Itraconazole is currently used for the treatment of cutaneous sporotrichosis. Terbinafine at a daily dose of 250 mg has been successfully applied to the treatment of cutaneous sporotrichosis. To compare the efficacy of 250 mg/day terbinafine and 100 mg/day itraconazole for the treatment of cutaneous sporotrichosis. A bidirectional cohort study was conducted on 55 patients receiving 250 mg/day terbinafine and 249 patients receiving 100 mg/day itraconazole. The latter patients were matched for age and clinical form to the terbinafine group at a ratio of 5:1. Sporothrix schenckii was isolated by culture from all patients (age range: 18-70 years), who were submitted to the standard care protocol consisting of clinical and laboratory evaluation and periodic visits. Cure was observed in 51 (92.7%) patients of the terbinafine group and 229 (92%) of the itraconazole group within a similar mean period of time (11.5 and 11.8 weeks, respectively). An increase in the terbinafine dose to 500 mg was necessary in two patients due to the lack of a response, and one patient presented recurrence. In the itraconazole group, two patients required a dose increase and three presented recurrence. Adverse events were equally frequent among patients receiving terbinafine (n = 4, 7.3%) and itraconazole (n = 19, 7.6%) and were generally mild without the need for drug discontinuation, except for two patients of the itraconazole group. Terbinafine administered at a daily dose of 250 mg is an effective and well-tolerated option for the treatment of cutaneous sporotrichosis.

  18. Stability of rapidly quenched and hydrogenated Mg-Ni-Y and Mg-Cu-Y alloys in extreme alkaline medium

    International Nuclear Information System (INIS)

    Gebert, A.; Khorkounov, B.; Wolff, U.; Mickel, Ch.; Uhlemann, M.; Schultz, L.

    2006-01-01

    Amorphous-nanocrystalline Mg 50 Ni 30 Y 20 and Mg 63 Ni 30 Y 7 and amorphous Mg 65 Cu 25 Y 10 alloys were produced by melt-spinning and characterized regarding their microstructure and thermal behaviour using XRD, TEM and DSC. Their electrochemical behaviour in the as-quenched state and after hydrogen charging at -25 mA/cm 2 for up to 20 h was studied in electrolytes with pH 5-7 and 13, but mainly in a battery electrolyte: 6 M KOH with pH 14.8 by means of anodic and cathodic polarization measurements. In the as-quenched state, the highest alloys stability was observed at pH 13. At pH 14.8, gradual oxidation and dissolution of copper or nickel governs the anodic behaviour before a passive state is attained. The dissolution of nickel is much more inhibited than that of copper due to its lower tendency to form soluble oxidized ions and to a stabilizing effect of higher fractions of yttrium in the alloy on the passivation. By galvanostatic charging, the Mg 65 Cu 25 Y 10 alloy shows the highest hydrogen absorption capacity followed by Mg 50 Ni 30 Y 20 and Mg 63 Ni 30 Y 7 . During the charging process, the alloys exhibit a change in the surface state chemistry, i.e. an enrichment of nickel- or copper-rich species, causing preferential oxidation and dissolution during subsequent exposure under free corrosion and anodic conditions. Mg-Ni-Y alloys demonstrate a higher stability during this treatment in extreme alkaline medium. The reasons for this and consequences regarding the use as electrode materials are discussed in detail

  19. Optical absorption and thermoluminescence in Mg O, Mg O:Ni and Mg O:Li irradiated at room temperature; Absorcion optica y termoluminiscencia en MgO, MgO:Ni y MgO:Li irradiados a temperatura ambiente

    Energy Technology Data Exchange (ETDEWEB)

    Delgado, L

    1984-07-01

    Optical absorption and thermoluminescence (TL) studies in Mg O, Mg O:Ni and Mg O:Li irradiated at room temperature are presented. In pure Mg O the thermal annihilation of Fe3+ by recombination with thermally released electrons at {approx} 90 and 175 degree centigree and the V center annealing by hole release up to 100 degree centigree cause the observed glow peaks at these temperatures. The TL excitation spectrum shows two maxima at 245 nm (electron center) and 288 nm (Fe3+). In Mg O:Ni X irradiation induces Fe{sup 2}+ {yields}- Fe{sup 3}+ and Ni{sup 2}+ {yields} Ni{sup 3}+ oxidations. Two TL emission bands centered at 110 degree centigree (red) and 80 o{sup C} (green) are assigned to electron release and their recombination at Fe{sup 3}+ and Ni{sup 3}+ respectively. In Mg O:Li two TL emission bands, one blue (430 nm) and the other red (730 nm) with excitation maxima at 245 nm (electron center) and 200 nm (hole center) respectively are observed. No V-center formation was detected in both Ni and Li doped samples. (Author) 42 refs.

  20. Thermophysical properties of some liquid binary Mg-based alloys

    Directory of Open Access Journals (Sweden)

    Plevachuk Y.

    2017-01-01

    Full Text Available In this study, some structure-sensitive thermophysical properties, namely, electrical conductivity, thermal conductivity and thermoelectric power of liquid binary alloys Al33.3Mg66.7, Mg47.6Zn52.4 and Mg33.3Zn66.7 (all in wt.%, as the most promising cast alloys to fabricate components for cars, aircraft and other complex engineering products, were investigated. The electrical conductivity and thermoelectric power were measured in a wide temperature range by the four-point contact method. The thermal conductivity was measured by the steady-state concentric cylinder method. The obtained results are compared with literature experimental and calculated data.

  1. Improved Mg-based alloys for hydrogen storage

    Energy Technology Data Exchange (ETDEWEB)

    Sapru, K.; Ming, L.; Stetson, N.T.; Evans, J. [Energy Conversion Devices, Inc., Troy, MI (United States)

    1998-08-01

    The overall objective of this on-going work is to develop low temperature alloys capable of reversibly storing at least 3 wt.% hydrogen, allowing greater than for 2 wt.% at the system level which is required by most applications. Surface modification of Mg can be used to improve its H-sorption kinetics. The authors show here that the same Mg-transition metal-based multi-component alloy when prepared by melt-spinning results in a more homogeneous materials with a higher plateau pressure as compared to preparing the material by mechanical grinding. They have also shown that mechanically alloyed Mg{sub 50}Al{sub 45}Zn{sub 5} results in a sample having a higher plateau pressure.

  2. Beta decay of 31,32Na and 31Mg

    International Nuclear Information System (INIS)

    Klotz, G.; Baumann, P.; Bounajma, M.; Huck, A.; Knipper, A.; Walter, G.; Poves, A.; Retamosa, J.

    1993-01-01

    31,32 Na and 31 Mg beta decays were studied at the CERN on-line mass separator ISOLDE by gamma, gamma-gamma and neutron-gamma measurements. In the 31 Na decay, the assignment of previously reported γ transitions and the observation of a new level at 3760 keV lead to a revised decay scheme. In the 31 Mg → 31 Al decay, a new decay scheme involves ten β branches and three states are reported for the first time. New spectroscopic results have been obtained in the 32 Na β - decay. A previously non-interpreted 1436 keV γ ray is now assigned in the 32 Mg scheme. (author) 33 refs., 16 figs., 12 tabs

  3. Beta-delayed proton emission from {sup 20}Mg

    Energy Technology Data Exchange (ETDEWEB)

    Lund, M.V.; Fynbo, H.O.U.; Howard, A.M.; Kirsebom, O.S.; Munch, M.; Riisager, K. [Aarhus University, Department of Physics and Astronomy, Aarhus C (Denmark); Andreyev, A.; Wadsworth, R. [University of York, Department of Physics, York (United Kingdom); Borge, M.J.G. [CSIC, Instituto de Estructura de la Materia, Madrid (Spain); CERN, ISOLDE, PH Department, Geneva 23 (Switzerland); Cederkaell, J. [Lund University, Department of Nuclear Physics, Lund (Sweden); Witte, H. de; Huyse, M.; Duppen, P. van [Instituut voor Kern- en Stralingsfysica, KU-Leuven, Leuven (Belgium); Fraile, L.M.; Vedia, V. [Universidad Complutense de Madrid, CEI Moncloa, Facultad de Ciencias Fisicas, Madrid (Spain); Greenlees, P.T.; Konki, J.; Rahkila, P. [University of Helsinki, Helsinki Institute of Physics, Helsinki (Finland); University of Jyvaeskylae, Department of Physics, Jyvaeskylae (Finland); Harkness-Brennan, L.J.; Judson, D.S.; Page, R.D. [University of Liverpool, Department of Physics, Oliver Lodge Laboratory, Liverpool (United Kingdom); Jonson, B.; Lindberg, S.; Nilsson, T. [Chalmers University of Technology, Department of Physics, Goeteborg (Sweden); Kurcewicz, J.; Madurga, M.; Rapisarda, E. [CERN, ISOLDE, PH Department, Geneva (Switzerland); Lazarus, I.; Pucknell, V. [STFC Daresbury, Daresbury, Warrington (United Kingdom); Lica, R. [CERN, ISOLDE, PH Department, Geneva (Switzerland); ' ' Horia Hulubei' ' National Institute of Physics and Nuclear Engineering, Magurele (Romania); Marginean, N.; Marginean, R.; Mihai, C.; Negret, A.; Pascu, S.; Rotaru, F.; Stanoiu, M.; Turturica, A. [' ' Horia Hulubei' ' National Institute of Physics and Nuclear Engineering, Magurele (Romania); Marroquin, I.; Nacher, E.; Perea, A.; Tengblad, O. [CSIC, Instituto de Estructura de la Materia, Madrid (Spain); Sotty, C. [Instituut voor Kern- en Stralingsfysica, KU-Leuven, Leuven (Belgium); ' ' Horia Hulubei' ' National Institute of Physics and Nuclear Engineering, Magurele (Romania); Warr, N. [Universitaet Koeln, Institut fuer Kernphysik, Koeln (Germany); Collaboration: IDS Collaboration

    2016-10-15

    Beta-delayed proton emission from {sup 20} Mg has been measured at ISOLDE, CERN, with the ISOLDE Decay Station (IDS) setup including both charged-particle and gamma-ray detection capabilities. A total of 27 delayed proton branches were measured including seven so far unobserved. An updated decay scheme, including three new resonances above the proton separation energy in {sup 20}Na and more precise resonance energies, is presented. Beta-decay feeding to two resonances above the Isobaric Analogue State (IAS) in {sup 20}Na is observed. This may allow studies of the 4032.9(2.4) keV resonance in {sup 19}Ne through the beta decay of {sup 20}Mg, which is important for the astrophysically relevant reaction {sup 15}O(α, γ){sup 19}Ne. Beta-delayed protons were used to obtain a more precise value for the half-life of {sup 20}Mg, 91.4(1.0) ms. (orig.)

  4. Electromagnetic densification of MgB2/Cu wires

    International Nuclear Information System (INIS)

    Woźniak, M; Glowacki, B A

    2014-01-01

    Electromagnetic compaction of in situ MgB 2 /Cu wire has been achieved using a custom-built 200 J device. The monofilament core packing density was increased by 8% and up to 31% for unreacted and reacted wires respectively. The higher density of the MgB 2 core resulted in a critical current density increase of up to 75% in comparison to that for cold-drawn-only wire. Applying this treatment to a wire with Cu powder additions to the core and with an optimized heat treatment resulted in one of the highest ever reported values of J c for MgB 2 /Cu wires of 6.83 × 10 3  A cm −2 at 4.2 K and 6 T. (paper)

  5. Strong, Ductile, and Thermally Stable bcc-Mg Nanolaminates.

    Science.gov (United States)

    Pathak, Siddhartha; Velisavljevic, Nenad; Baldwin, J Kevin; Jain, Manish; Zheng, Shijian; Mara, Nathan A; Beyerlein, Irene J

    2017-08-15

    Magnesium has attracted attention worldwide because it is the lightest structural metal. However, a high strength-to-weight ratio remains its only attribute, since an intrinsic lack of strength, ductility and low melting temperature severely restricts practical applications of Mg. Through interface strains, the crystal structure of Mg can be transformed and stabilized from a simple hexagonal (hexagonal close packed hcp) to body center cubic (bcc) crystal structure at ambient pressures. We demonstrate that when introduced into a nanocomposite bcc Mg is far more ductile, 50% stronger, and retains its strength after extended exposure to 200 C, which is 0.5 times its homologous temperature. These findings reveal an alternative solution to obtaining lightweight metals critically needed for future energy efficiency and fuel savings.

  6. MgB2 superconducting wires basics and applications

    CERN Document Server

    2016-01-01

    The compendium gives a complete overview of the properties of MgB2 (Magnesium Diboride), a superconducting compound with a transition temperature of Tc = 39K, from the fundamental properties to the fabrication of multifilamentary wires and to the presentation of various applications. Written by eminent researchers in the field, this indispensable volume not only discusses superconducting properties of MgB2 compounds, but also describes known preparation methods of thin films and of bulk samples obtained under high pressure methods. A unique selling point of the book is the detailed coverage of various applications based on MgB2, starting with MRI magnets and high current cables, cooled by Helium (He) vapor. High current cables cooled by liquid hydrogen are also highlighted as an interesting alternative due to the shrinking He reserves on earth. Other pertinent subjects comprise permanent magnets, ultrafine wires for space applications and wind generator projects.

  7. Thermodynamic evaluation of the Cu-Mg-Zr system

    International Nuclear Information System (INIS)

    Haemaelaeinen, M.; Zeng, K.

    1999-01-01

    The thermodynamic evaluation of the Cu-Mg-Zr system is presented in this paper. A literature survey was carried out first based on the most recent literature, which was scanned from the THERMET literature database. The evaluation of the thermodynamic parameters was carried out using Thermo-Calc (version H) software. The evaluation of the Cu-Mg-Zr system was carried out using the most recent experimental data from the literature and a set of DTA measurements. DTA measurements were done using alumina (Al 2 O 3 ) crucibles under helium atmosphere with the niobium (Nb) reference crucible. The evaluated Cu-Mg-Zr phase diagram fitted well with experimental data with the liquidus data in a limited range of composition. There were two miscibility gaps observe in the system. New τ phase was detected using the X-ray and microscopic analysis and the data was used in this evaluation. (orig.)

  8. The electric dipole moment of magnesium deuteride, MgD.

    Science.gov (United States)

    Steimle, Timothy C; Zhang, Ruohan; Wang, Hailing

    2014-06-14

    The (0,0) A(2)Π-X (2)Σ(+) band of a cold molecular beam sample of magnesium monodeuteride, MgD, has been recorded field-free and in the presence of a static electric field of up to 11 kV/cm. The lines associated with the lowest rotational levels are detected for the first time. The field-free spectrum was analyzed to produce an improved set of fine structure parameters for the A(2)Π (v = 0) state. The observed electric field induced splittings and shifts were analyzed to produce permanent electric dipole moments, μ(el) of 2.567(10)D and 1.31(8)D for A(2)Π (v = 0) and X(2)Σ(+)(v = 0) states, respectively. The recommended value for μ(el)(X(2)Σ(+) (v = 0)) for MgH, based upon the measured value for MgD, is 1.32(8)D.

  9. Sequential magnetic switching in Fe/MgO(001) superlattices

    Science.gov (United States)

    Magnus, F.; Warnatz, T.; Palsson, G. K.; Devishvili, A.; Ukleev, V.; Palisaitis, J.; Persson, P. O. Å.; Hjörvarsson, B.

    2018-05-01

    Polarized neutron reflectometry is used to determine the sequence of magnetic switching in interlayer exchange coupled Fe/MgO(001) superlattices in an applied magnetic field. For 19.6 Å thick MgO layers we obtain a 90∘ periodic magnetic alignment between adjacent Fe layers at remanence. In an increasing applied field the top layer switches first followed by its second-nearest neighbor. For 16.4 Å MgO layers, a 180∘ periodic alignment is obtained at remanence and with increasing applied field the layer switching starts from the two outermost layers and proceeds inwards. This sequential tuneable switching opens up the possibility of designing three-dimensional magnetic structures with a predefined discrete switching sequence.

  10. Growth and scintillation properties of BaMgF4

    International Nuclear Information System (INIS)

    Yanagida, Takayuki; Kawaguchi, Noriaki; Fujimoto, Yutaka; Sugiyama, Makoto; Furuya, Yuki; Kamada, Kei; Yokota, Yuui; Yoshikawa, Akira; Chani, Valery

    2010-01-01

    By using the micro-pulling down (μ-PD) method, the barium magnesium fluoride (BaMgF 4 ) single crystalline scintillator was produced. The crystal was cut and mirror polished to the physical dimensions of 1x2x10 mm 3 for examination of scintillation properties. BaMgF 4 demonstrated ∼70% transmittance in wavelength range above 170 nm, and strong emission peaking around 205 nm was observed under X-ray excitation. The absolute light yield of BaMgF 4 was 1300±100 ph/MeV, and the decay time profile showed two components as 0.57±0.01 (70%) and 2.2±0.31 (30%) ns at room temperature.

  11. High production rate of IBAD-MgO buffered substrate

    Energy Technology Data Exchange (ETDEWEB)

    Yoshizumi, M., E-mail: myoshizumi@istec.or.j [Superconductivity Research Laboratory, ISTEC, Shinonome 1-10-13, Koto-ku, Tokyo 135-0062 (Japan); Miyata, S.; Ibi, A.; Fukushima, H.; Yamada, Y.; Izumi, T.; Shiohara, Y. [Superconductivity Research Laboratory, ISTEC, Shinonome 1-10-13, Koto-ku, Tokyo 135-0062 (Japan)

    2009-10-15

    The conventional IBAD (Ion Beam Assisted Deposition) process using fluorite materials yields low production rates, resulting in high production cost, which reduces the motivation for practical application in spite of its high quality. The IBAD process using rock salt materials, e.g. MgO, is well known as a strong candidate of practical application due to its potential of high production rate and high in-plane grain alignment. In this work, the IBAD-MgO process was investigated for a newly developed architecture of PLD (Pulsed Laser Deposition)-CeO{sub 2}/sputter-LMO (LaMnO{sub 3})/IBAD-MgO/sputter-GZO (Gd{sub 2}Zr{sub 2}O{sub 7})/Hastelloy{sup TM} to make long buffered metal tapes with high properties and a high production rate. The 50 m-long IBAD-MgO substrates with about 4 deg. of DELTAphiCeO{sub 2} in an XRD phi scan could be fabricated repeatedly. A GdBCO (GdBa{sub 2}Cu{sub 3}O{sub x}) layer deposited on the buffered substrate showed the minimum I{sub c} value of 325 A/cm-w in a 41 m-long tape. Almost of the tape showed 500-600 A/cm-w of I{sub c} value. The deposition time for the IBAD-MgO layer was 60 s which was about 2 orders of magnitude shorter than the conventional IBAD process. The production rate of 24 m/h was realized at the IBAD-MgO process to fabricate the GdBCO coated conductor with high J{sub c} and I{sub c} properties.

  12. Divorced Eutectic Solidification of Mg-Al Alloys

    Science.gov (United States)

    Monas, Alexander; Shchyglo, Oleg; Kim, Se-Jong; Yim, Chang Dong; Höche, Daniel; Steinbach, Ingo

    2015-08-01

    We present simulations of the nucleation and equiaxed dendritic growth of the primary hexagonal close-packed -Mg phase followed by the nucleation of the -phase in interdendritic regions. A zoomed-in region of a melt channel under eutectic conditions is investigated and compared with experiments. The presented simulations allow prediction of the final properties of an alloy based on process parameters. The obtained results give insight into the solidification processes governing the microstructure formation of Mg-Al alloys, allowing their targeted design for different applications.

  13. Comparison of characteristics of LiF:Mg,Ti e LiF:Mg,Cu,P thermoluminescent dosemeters; Comparacao das caracteristicas dos dosimetros termoluminescentes LiF:Mg,Ti e LiF:Mg,Cu,P

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, M.S.; Filipov, D., E-mail: dfilipov@utfpr.edu.br [Universidade Tecnologica Federal do Parana (UTFPR/DAFIS), Curitiba, PR (Brazil). Departamento Academicao de Fisica; Schelin, H.R. [Instituto de Pesquisa Pele Pequeno Principe (IPPPP), Curitiba, PR (Brazil)

    2014-07-01

    The aim of the current study was to compare the thermoluminescent dosimeters LiF:Mg,Ti (TLD-100) and LiF:Mg,Cu,P (MCP) data, which were acquired by the Federal Technological University - Parana. Tests were realized, for this purpose, such as: sensitivity (only one MCP TLD did not present results within the limit range), linearity (whose MCP result was better than the TLD-100 one), energy dependence (TLD-100 presented lower variation than MCP TLD) and reproducibility (whose TLD-100 results were better than the MCP ones). The results from both dosimeters show that these TLDs attend radiodiagnostic dosimetry criteria, however MCP had more satisfactory results. (author)

  14. Exploring the island of inversion with the d({sup 30}Mg,p){sup 31}Mg reaction

    Energy Technology Data Exchange (ETDEWEB)

    Bildstein, Vinzenz

    2010-12-07

    In this thesis the results of a d({sup 30}Mg,p){sup 31}Mg experiment at REX-ISOLDE are presented. {sup 31}Mg is located directly on the border of the so-called ''Island of Inversion'', a region of the nuclear chart around {sup 32}Mg where deformed intruder states of the fp shell form the ground states of the nuclei instead of the normal spherical states of the sd shell. A recent experiment has shown the ground state of {sup 31}Mg to be a 1/2{sup +} state and indicates more than 90% intruder configuration. The question whether the low-lying excited states of {sup 31}Mg are deformed intruder states as well or rather spherical states from the sd shell, indicating shape coexistence, is still open. The d({sup 30}Mg,p) {sup 31}Mg reaction is thus a good tool to gain more insight into the nature of the Island of Inversion. In the framework of this thesis the angular distribution of protons was measured for the second excited state at 221 keV in coincidence with de-excitation {gamma}-rays. The angular distribution was compared to DWBA calculations for different transferred orbital momenta, identifying the state for the first time as an l=1 state. The experiment was performed with the new charged particle detector setup T-REX. The setup is optimized for transfer reactions with radioactive beams in inverse kinematics. T-REX was developed, built, installed, and used for this first one neutron transfer experiment in the context of this thesis. The T-REX setup consists of {delta}E-E{sub Rest} telescopes made out of position sensitive silicon detectors that cover almost 4{pi} of the solid angle and can be combined with the MINIBALL {gamma}-ray detector array. It has a large solid angle for the detection and identification of the light recoils from transfer reactions. T-REX allows in combination with the MINIBALL Germanium detector array the tagging of the excited states by their characteristic {gamma}-rays. The combination of T-REX and MINIBALL achieves an

  15. Microstructure and fatigue properties of Mg-to-steel dissimilar resistance spot welds

    International Nuclear Information System (INIS)

    Liu, L.; Xiao, L.; Chen, D.L.; Feng, J.C.; Kim, S.; Zhou, Y.

    2013-01-01

    Highlights: ► Mg/steel dissimilar spot weld had the same fatigue strength as Mg/Mg similar weld. ► Crack propagation path of Mg/Mg and Mg/steel welds was the same. ► Penetration of Zn into the Mg base metal led to crack initiation of Mg/steel weld. ► HAZ weakening and stress concentration led to crack initiation of Mg/Mg weld. -- Abstract: The structural application of lightweight magnesium alloys in the automotive industry inevitably involves dissimilar welding with steels and the related durability issues. This study was aimed at evaluating the microstructural change and fatigue resistance of Mg/steel resistance spot welds, in comparison with Mg/Mg welds. The microstructure of Mg/Mg spot welds can be divided into: base metal, heat affected zone and fusion zone (nugget). However, the microstructure of Mg/steel dissimilar spot welds had three different regions along the joined interface: weld brazing, solid-state joining and soldering. The horizontal and vertical Mg hardness profiles of Mg/steel and Mg/Mg welds were similar. Both Mg/steel and Mg/Mg welds were observed to have an equivalent fatigue resistance due to similar crack propagation characteristics and failure mode. Both Mg/steel and Mg/Mg welds failed through thickness in the magnesium sheet under stress-controlled cyclic loading, but fatigue crack initiation of the two types of welds was different. The crack initiation of Mg/Mg welds was occurred due to a combined effect of stress concentration, grain growth in the heat affected zone (HAZ), and the presence of Al-rich phases at HAZ grain boundaries, while the penetration of small amounts of Zn coating into the Mg base metal stemming from the liquid metal induced embrittlement led to crack initiation in the Mg/steel welds.

  16. A study of stability of MgH{sub 2} in Mg-8at%Al alloy powder

    Energy Technology Data Exchange (ETDEWEB)

    Tanniru, Mahesh; Ebrahimi, Fereshteh [Materials Science and Engineering Department, University of Florida, Gainesville, FL 32611 (United States); Slattery, Darlene K. [Florida Solar Energy Center (FSEC), Cocoa, FL (United States)

    2010-04-15

    To investigate the effect of Al addition on the stability of magnesium hydride, the hydrogenation characteristics of a Mg-8at%Al alloy powder synthesized using the electrodeposition technique were evaluated. The characterization of the hydrogenation behavior within the 180 C-280 C temperature range and the subsequent microstructural analysis elucidated that the amount of Al present in the hydride decreased with increasing temperature. This observation suggests that Al has very low solubility in magnesium hydride but Al can be accommodated in MgH{sub 2} by processing under non-equilibrium conditions. Pressure-composition isotherms were developed at different temperatures for the Mg-Al powder as well as pure Mg powder. The results indicate that the enthalpy of formation was slightly lower for the Mg-8at%Al powder while the enthalpy of dissociation did not change. The absence of noticeable influence of Al addition on the stability of magnesium hydride is attributed to its lack of solubility. (author)

  17. Effect of amorphous lamella on the crack propagation behavior of crystalline Mg/amorphous Mg-Al nanocomposites

    Science.gov (United States)

    Hai-Yang, Song; Yu-Long, Li

    2016-02-01

    The effects of amorphous lamella on the crack propagation behavior in crystalline/amorphous (C/A) Mg/Mg-Al nanocomposites under tensile loading are investigated using the molecular dynamics simulation method. The sample with an initial crack of orientation [0001] is considered here. For the nano-monocrystal Mg, the crack growth exhibits brittle cleavage. However, for the C/A Mg/Mg-Al nanocomposites, the ‘double hump’ behavior can be observed in all the stress-strain curves regardless of the amorphous lamella thickness. The results indicate that the amorphous lamella plays a critical role in the crack deformation, and it can effectively resist the crack propagation. The above mentioned crack deformation behaviors are also disclosed and analyzed in the present work. The results here provide a strategy for designing the high-performance hexagonal-close-packed metal and alloy materials. Project supported by the National Natural Science Foundation of China (Grant Nos. 11372256 and 11572259), the 111 Project (Grant No. B07050), the Program for New Century Excellent Talents in University of Ministry of Education of China (Grant No. NCET-12-1046), and the Program for New Scientific and Technological Star of Shaanxi Province, China (Grant No. 2012KJXX-39).

  18. Hydrothermal replacement of calcite by Mg-carbonates

    Science.gov (United States)

    Jonas, Laura; Mueller, Thomas; Dohmen, Ralf

    2014-05-01

    The transport of heat and mass through the Earth's crust is coupled to mineral reactions and the exchange of isotopes and elements between different phases. Carbonate minerals are a major constituent of the Earth's crust and play an important role in different physical, chemical and even biological processes. In this experimental study, the element exchange reaction between calcite (CaCO3) and a Mg-rich fluid phase is investigated under hydrothermal conditions. Single crystals of calcite (2x2x2 mm) react with 1 ml of a 1 M MgCl2 solution at 200° C in a Teflon-lined steel autoclave for different times between one day and four weeks. The reaction leads to the formation of a porous reaction front and the pseudomorphic replacement of calcite by dolomite [CaMg(CO3)2] and magnesite (MgCO3). Scanning electron microscopy revealed that the reaction rim consists of small Mg-carbonate rhombs closely attached to each other, suggesting that the replacement reaction takes place by a dissolution-precipitation mechanism. Typically, the observed reaction front can be divided into two different domains. The outer part of the reaction rim, i.e. from the mineral surface in contact to the fluid inwards, consists of magnesite, whereas the inner part of the rim surrounding the unreacted calcite core consists of Ca-rich dolomite. The formation of a porous microstructure that varies in different parts of the reaction rim is a direct result of the large molar volume change induced by the replacement of calcite by magnesite and dolomite. The developing porosity therefore creates fluid pathways that promote the progress of the reaction front towards the unreacted core of the single crystal. Compositional profiles measured perpendicular to the mineral surface across the reactions rims using electron microprobe (EMPA) further revealed a compositional gradient within the reaction rim with regard to the structure-forming elements Mg and Ca. Here, the amount of Mg incorporated in both product

  19. Brand versus generic dispensing trend for ciprofloxacin 500 mg, levofloxacin 500 mg, and moxifloxacin 400 mg (oral dosage forms) among pharmacies of Karachi, Pakistan.

    Science.gov (United States)

    Zehra, Fatima; Naqvi, Atta Abbas; Tasneem, Sumbul; Ahmad, Rizwan; Ahmad, Niyaz; Shamsi, Adnan Zia; Asghar, Naqiya Ali; Khan, Ghufran Ullah

    2017-01-01

    Pakistan spends 0.7% of its gross domestic product on health. The public sector health-care system provides services to 22% of population thus paving the way for a dominant private sector. Patients in Pakistan mostly pay their medical expenses directly, and 64% of the health expenditures are borne by the household. Expenditure on medicine constitutes 43% of the total household expenditure. A quantitative cross-sectional study was conducted in Karachi, Pakistan, for a month. It was aimed at gathering response from different pharmacies to understand the brand versus generic dispensing trend of ciprofloxacin 500 mg, levofloxacin 500 mg, and moxifloxacin 400 mg oral dosage forms. The study employed convenience sampling and used a survey checklist. The data gathered was entered in SPSS version 22. The mean price per tablet for ciprofloxacin brand and generic was reported at Pakistani Rupees (PKR) 48.44 and PKR 26.85, respectively. The trend for dispensing ciprofloxacin highlighted a split in the market between brand (51%) and generic (49%). For levofloxacin brand and generic, the price per tablet was reported at PKR 36.50 and PKR 36.15 respectively, and despite same price, the market was dominated by generic levofloxacin (92%). Due to a price difference between brand and generic moxifloxacin, i.e., PKR 129.44 and PKR 71.91, respectively, the market was mostly occupied by the generic form (75%). Pricing mechanism must be revisited, and the authorities should take stern actions against any illegitimate price hike. The surging burden of drug expenditure on poorer sections of the society must be addressed by the government on an urgent basis.

  20. Farklı Canlı Ağırlıklardaki Keçilerden Elde Edilen Çiğ Sütlerin Sert, Yarı Sert ve Yumuşak Peynir Üretim Standartlarına Uygunluklarının Belirlenmesi

    OpenAIRE

    Çimen, Murat; Topçu, Hakan; Ölcal, Mehmet Cengiz

    2013-01-01

    Bu araştırmanın amacı farklı canlı ağırlıklara sahip keçilerden elde edilen çiğ sütlerin sert, yarı sert ve sert peynir standartlarına göre uygunluğunu araştırmaktır. Veriler Tunceli ilinin İsmailli köyünde yetiştirilen bir Saanen keçi sürüsünden elde edilmiştir. Ağır ve hafif keçiler için sütteki toplam yağ seviyeleri yumuşak peynir üretimi için bildirilen standartlara uygun bulunmuştur. Her iki gruptaki (ağır ve hafif) toplam kurumadde ve protein oranları üç peynir çeşidi (yumuşak, yarı ser...

  1. Habits of Reading and Library Use of the Ethnic Minority Children in Multi-cultural Societies Çok Kültürlü Toplumlarda Etnik Azınlık Çocuklarının Okuma ve Kütüphane Kullanma Alışkanlıkları

    Directory of Open Access Journals (Sweden)

    Bülent Yılmaz

    2000-12-01

    Full Text Available In this study, it is examined that habits of reading and library use of the ethnic minority children live in multi-cultural societies in theoretical base. Habits of reading and library use are tools which have important functions incultural adaptation of ethnic minority children. These habits can help the cultural adaptation of the children, especially, by contributing to their language developments and educational achievements. Bu çalışmada, çok kültürlü toplumlarda yaşayan etnik azınlık çocuklarının okuma ve kütüphane kullanma alışkanlıkları kuramsal olarak ele alınmıştır. Okuma ve kütüphane kullanma alışkanlıkları etnik azınlık çocukları için kültürel uyumda önemli işlevlere sahip araçlardır. Bu alışkalıklar, çocuklarda, özellikle, dil gelişimi ve eğitimde başarıya katkıda bulunarak kültürel uyuma yardımcı olurlar.

  2. Comparison of the Effect of 800 mg Ibuprofen and 30 mg Predenisolone on Relief of Post Endodontic Pain

    Directory of Open Access Journals (Sweden)

    S.M. Jalalzadeh

    2009-04-01

    Full Text Available Introduction & Objective: One of the important problems in dentistry is post endodontic pains .The purpose of this study was comparison of the effect of prophylactic oral ibuprofen 800mg and oral predenisolone 30mg on prevention of post endodontic pain.Materials & Methods: The present study is a double-blind, randomized and controlled trial. It was conducted on 60 patient (16men and 44 women between the ages of 18-63 who needed endodontic treatment. Inclusive criteria for selecting of patients were: need for root canal therapy in one of the posterior teeth, having no systemic problem, no evidence of abscess; not taking analgesic or similar drug for at least 6 hours before treatment. Patients were divided into three experimental groups randomly taking one of the drugs before the treatment {ibuprofen 800 mg, prednisolone30mg and placebo (oral dextrose}. Patients completed VAS at 6,12 and 24 hours post root canal therapy and analyzed using the spss15 by chi-square, ANOVA test and Tukey test.Results: During 24 hours after treatment post endodontic pain is 95%- 100% in the placebo group. The prevalence of no-pain was not significant 6, 12 and 24 hours after treatment between the ibuprofen and predenisolone groups. The mean scale of pain in ibuprofen and predenisolone groups was significantly lower than placebo group 6, 12 and 24 hours after treatment. Differences between the drug groups are significant only on 6 and 12 hours after treatment.Conclusion: Post endodontic pains are present 24 hours after treatment. 6 and 12 hours after treatment 30 mg predenisolone are significantly better for pain relief than 800 mg ibuprofen. But after 24 hours it is not significant.

  3. Permanent magnet with MgB{sub 2} bulk superconductor

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, Akiyasu, E-mail: yamamoto@appchem.t.u-tokyo.ac.jp [The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-8656 (Japan); JST-PRESTO, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012 (Japan); Ishihara, Atsushi; Tomita, Masaru [Railway Technical Research Institute, 2-8-38 Hikari, Kokubunji, Tokyo 185-8540 (Japan); Kishio, Kohji [The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-8656 (Japan)

    2014-07-21

    Superconductors with persistent zero-resistance currents serve as permanent magnets for high-field applications requiring a strong and stable magnetic field, such as magnetic resonance imaging. The recent global helium shortage has quickened research into high-temperature superconductors (HTSs)—materials that can be used without conventional liquid-helium cooling to 4.2 K. Herein, we demonstrate that 40-K-class metallic HTS magnesium diboride (MgB{sub 2}) makes an excellent permanent bulk magnet, maintaining 3 T at 20 K for 1 week with an extremely high stability (<0.1 ppm/h). The magnetic field trapped in this magnet is uniformly distributed, as for single-crystalline neodymium-iron-boron. Magnetic hysteresis loop of the MgB{sub 2} permanent bulk magnet was determined. Because MgB{sub 2} is a simple-binary-line compound that does not contain rare-earth metals, polycrystalline bulk material can be industrially fabricated at low cost and with high yield to serve as strong magnets that are compatible with conventional compact cryocoolers, making MgB{sub 2} bulks promising for the next generation of Tesla-class permanent-magnet applications.

  4. Characterization of the microstructure in Mg based alloy

    KAUST Repository

    Kutbee, Arwa T

    2013-01-01

    hardening is essential for age hardenable Mg-based alloys. In this work, microstructural investigation of the Mg–1.4Sn–1.3Zn–0.1Mn (at.%) precipitation system was performed using TEM. The chemical composition of the precipitates was analyzed using EDS. APT

  5. Microwave absorption studies of MgB2 superconductor

    Indian Academy of Sciences (India)

    band (9–. 10 GHz) spectrometer. Both polycrystalline pellet and single-grain MgB2, having nearly the same Tc (∼ 39 K) and same size (3×2×1 mm3), were used in the present investigations. Low field modulated microwave absorption signals ...

  6. Electronic structure and superconductivity of MgB 2

    Indian Academy of Sciences (India)

    Results of ab initio electronic structure calculations on the compound, MgB2, using the FPLAPW method employing GGA for the exchange–correlation energy are presented. Total energy minimization enables us to estimate the equilibrium volume, / ratio and the bulk modulus, all of which are in excellent agreement with ...

  7. Individual Low-Energy Toroidal Dipole State in Mg 24

    Science.gov (United States)

    Nesterenko, V. O.; Repko, A.; Kvasil, J.; Reinhard, P.-G.

    2018-05-01

    The low-energy dipole excitations in Mg 24 are investigated within the Skyrme quasiparticle random phase approximation for axial nuclei. The calculations with the force SLy6 reveal a remarkable feature: the lowest IπK =1-1 excitation (E =7.92 MeV ) in Mg 24 is a vortical toroidal state (TS) representing a specific vortex-antivortex realization of the well-known spherical Hill's vortex in a strongly deformed axial confinement. This is a striking example of an individual TS which can be much more easily discriminated in experiment than the toroidal dipole resonance embracing many states. The TS acquires the lowest energy due to the huge prolate axial deformation in Mg 24 . The result persists for different Skyrme parametrizations (SLy6, SVbas, SkM*). We analyze spectroscopic properties of the TS and its relation with the cluster structure of Mg 24 . Similar TSs could exist in other highly prolate light nuclei. They could serve as promising tests for various reactions to probe a vortical (toroidal) nuclear flow.

  8. The M/G/1 queue with permanent customers

    NARCIS (Netherlands)

    Boxma, O.J.; Cohen, J.W.

    1991-01-01

    The authors examine an M/G/1 FCFS (first come, first served) queue with two types of customers: ordinary customers, who arrive according to a Poisson process, and permanent customers, who immediately return to the end of the queue after having received a service. The influence of the permanent

  9. Laser cladding of Zr on Mg for improved corrosion properties

    International Nuclear Information System (INIS)

    Subramanian, R.; Sircar, S.; Mazumder, J.

    1989-01-01

    This paper reports the results of laser cladding of Mg-2wt%Zr, and Mg-5wt%Zr powder mixture onto magnesium. The microstructure of the laser clad was studied. From the microstructural study, the epitaxial regrowth of the clad region on the underlying substrate was observed. Martensite plates of different size were observed in transmission electron microscope for MG-2wt%Zr and Mg-5wt%Zr laser clad. The corrosion properties of the laser clad were evaluated in sea water (3.5% NaCl). The position of the laser claddings in the galvanic series of metals in sea water, the anodic polarization characteristics of the laser claddings and the protective nature and the stability of the passivating film formed have been determined. The formation of pits on the surface of the laser clad subjected to corrosion is reported. The corrosion properties of the laser claddings are compared with that of the commercially used magnesium alloy AZ91B

  10. Comparison of the effects of esomeprazole 40 mg, rabeprazole 20 mg, lansoprazole 30 mg, and pantoprazole 40 mg on intragastrıc pH in extensive metabolizer patients with gastroesophageal reflux disease.

    Science.gov (United States)

    Çelebi, Altay; Aydın, Dinçer; Kocaman, Orhan; Konduk, Buğra Tolga; Şentürk, Ömer; Hülagü, Sadetin

    2016-09-01

    Studies on the therapeutic efficacy of proton pump inhibitors (PPIs) in patients with gastroesophageal reflux disease (GERD) have been recently published. In most of these studies, comparison of only two PPIs have been made. There are few studies on the comparison of four or more PPIs. We aimed to compare the acid inhibitory effects of esomeprazole 40 mg, rabeprazole 20 mg, lansoprazole 30 mg, and pantoprazole 40 mg on days 1 and 5 of treatment in patients with GERD, who were extensive metabolizers in regard to the CYP2C19 genotype. Helicobacter pylori-negative with typical symptoms of GERD patients were randomly divided into four treatment groups. Efficacy analysis on days 1 and 5 were performed on the four groups which comprised 10 (esomeprazole), 11 (rabeprazole), 10 (lansoprazole), and 10 (pantoprazole) patients. On day 1 of PPI treatment, the mean percentage of time with intragastric Ph>4 were 54%, 58%, 60%, and 35% for the groups, respectively, and on day 5, these values were 67%, 60%, 68%, and 59%, respectively. Esomeprazole, rabeprazole, and lansoprazole were found to be superior to pantoprazole on the first day of treatment. Pantoprazole is a less potent proton pump inhibitor than the other PPIs tested on the first day of treatment. When the time needed to raise the intragatric pH to over 4 was evaluated, esomeprazole was found to have the most rapid action, followed by lansoprazole and rabeprazole.

  11. Structure and electron-ion correlation in liquid Mg

    Energy Technology Data Exchange (ETDEWEB)

    Tahara, Shuta [Graduate School of Sciences, Kyushu University, 4-2-1 Ropponmatsu Chuo-ku, Fukuoka 810-8560 (Japan); Fujii, Hiroyuki [Graduate School of Sciences, Kyushu University, 4-2-1 Ropponmatsu Chuo-ku, Fukuoka 810-8560 (Japan); Japan Synchrotron Radiation Research Institute, 1-1-1 Kouto Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); Yokota, Yukinobu [Graduate School of Sciences, Kyushu University, 4-2-1 Ropponmatsu Chuo-ku, Fukuoka 810-8560 (Japan); Kawakita, Yukinobu [Department of Physics, Faculty of Sciences, Kyushu University, 4-2-1 Ropponmatsu Chuo-ku, Fukuoka 810-8560 (Japan); Kohara, Shinji [Japan Synchrotron Radiation Research Institute, 1-1-1 Kouto Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); Takeda, Shin' ichi [Department of Physics, Faculty of Sciences, Kyushu University, 4-2-1 Ropponmatsu Chuo-ku, Fukuoka 810-8560 (Japan)]. E-mail: takeda@rc.kyushu-u.ac.jp

    2006-11-15

    For liquid Mg at 700 deg. C, structure factors were obtained from both neutron and X-ray diffraction measurements. The bond angle and coordination number distributions were derived from the reverse Monte Carlo analysis. By a combination of both structure factors, charge density function and electron-ion partial structure factor were deduced.

  12. DISTRIBUTION OF MAJOR ELEMENTS (NA, K, CA, MG) IN THE ...

    African Journals Online (AJOL)

    Levels of sodium, potassium, calcium and magnesium were determined in plant organs (bud, flowers, fruit, seed, leaves, stems, roots, cobs, styles, shaft, grains and efflorescences) of three Fadama farms located in Ifaki-Ekiti, Ado-Ekiti and Ikere-Ekiti of Ekiti State, Nigeria. The highest levels of Mg, K, Na and Ca were ...

  13. EXAFS investigations of Cu-Mg-O compound

    CERN Document Server

    Sidorenko, A F; Babanov, Y A; Naumov, S V; Samokhvalov, A A

    2001-01-01

    The interest to systems containing copper oxide is connected with the problem of high-temperature superconductivity because of the closeness of its basic physical properties and properties of superconductor mother Cu-compounds. In this work, EXAFS study of the Cu sub 0 sub . sub 2 Mg sub 0 sub . sub 8 O compound is presented. A new iterative algorithm of the solution of ill-posed problem on determining three partial pair correlation functions from one EXAFS-data set near the Cu K-edge is described. The results of X-ray scattering study of a given sample show a presence of a single phase with the MgO structure and a lattice parameter of 4.219 A instead of 4.208 A for pure MgO. From the EXAFS investigations, we find the local distortion of the lattice. We revealed that the short range order differs both from a hypothetical alloy with the MgO structure and from copper oxide.

  14. Preparation and characterization of MgB2 superconductor

    Indian Academy of Sciences (India)

    2Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400 005, India. Abstract. The MgB2 superconductor, synthesized using solid-state and liquid-phase sintering methods, have been characterized for various properties. The upper critical field, irreversibility line and critical current density have been ...

  15. Oncolytic Maraba Virus MG1 as a Treatment for Sarcoma.

    Science.gov (United States)

    Le Boeuf, Fabrice; Selman, Mohammed; Son, Hwan Hee; Bergeron, Anabel; Chen, Andrew; Tsang, Jovian; Butterwick, Derek; Arulanandam, Rozanne; Forbes, Nicole E; Tzelepis, Fanny; Bell, John C; Werier, Joel; Abdelbary, Hesham; Diallo, Jean-Simon

    2017-09-15

    The poor prognosis of patients with advanced bone and soft-tissue sarcoma has not changed in the past several decades, highlighting the necessity for new therapeutic approaches. Immunotherapies, including oncolytic viral (OV) therapy, have shown great promise in a number of clinical trials for a variety of tumor types. However, the effective application of OV in treating sarcoma still remains to be demonstrated. Although few pre-clinical studies using distinct OVs have been performed and demonstrated therapeutic benefit in sarcoma models, a side-by-side comparison of clinically relevant OV platforms has not been performed. Four clinically relevant OV platforms (Reovirus, Vaccinia virus, Herpes-simplex virus and Rhabdovirus) were screened for their ability to infect and kill human and canine sarcoma cell lines in vitro, and human sarcoma specimens ex vivo. In vivo treatment efficacy was tested in a murine model. The rhabdovirus MG1 demonstrated the highest potency in vitro. Ex vivo, MG1 productively infected more than 80% of human sarcoma tissues tested, and treatment in vivo led to a significant increase in long-lasting cures in sarcoma-bearing mice. Importantly, MG1 treatment induced the generation of memory immune response that provided protection against a subsequent tumor challenge. This study opens the door for the use of MG1-based oncolytic immunotherapy strategies as treatment for sarcoma or as a component of a combined therapy. © 2017 UICC.

  16. Thermically stimulated exoelectronic emissions and thermoluminescence of MgO

    International Nuclear Information System (INIS)

    Chubaci, J.F.D.

    1987-01-01

    In this work, studies were performed on the following topics: i) thermically stimulated exoelectronic emission (TSEE) in pure MgO single crystals ion implanted, submitted to thermal treatment with fast on slow cooling and water adsorption; ii) ultraviolet light effect on TSEE; iii) thermoluminescent emission; iv) crystallization of FeCoB amorphous alloys. (A.C.A.S.) [pt

  17. Mechanism of Mg2+-Accompanied Product Release in Sugar Nucleotidyltransferases.

    Science.gov (United States)

    Vithani, Neha; Ankush Jagtap, Pravin Kumar; Verma, Sunil Kumar; Tripathi, Ravi; Awasthi, Shalini; Nair, Nisanth N; Prakash, Balaji

    2018-03-06

    The nucleotidyl transfer reaction, catalyzed by sugar nucleotidyltransferases (SNTs), is assisted by two active site Mg 2+ ions. While studying this reaction using X-ray crystallography, we captured snapshots of the pyrophosphate (product) as it exits along a pocket. Surprisingly, one of the active site Mg 2+ ions remains coordinated to the exiting pyrophosphate. This hints at the participation of Mg 2+ in the process of product release, besides its role in catalyzing nucleotidyl transfer. These observations are further supported by enhanced sampling molecular dynamics simulations. Free energy computations suggest that the product release is likely to be rate limiting in SNTs, and the origin of the high free energy barrier for product release could be traced back to the "slow" conformational change of an Arg residue at the exit end of the pocket. These results establish a dual role for Mg 2+ , and propose a general mechanism of product release during the nucleotidyl transfer by SNTs. Copyright © 2018 Elsevier Ltd. All rights reserved.

  18. Suppression of Mg propagation into subsequent layers grown by MOCVD

    Science.gov (United States)

    Agarwal, Anchal; Tahhan, Maher; Mates, Tom; Keller, Stacia; Mishra, Umesh

    2017-01-01

    Low temperature (LT) flow modulation epitaxy (FME) or "pulsed" growth was successfully used to prevent magnesium from Metalorganic Chemical Vapor Deposition (MOCVD) grown p-GaN:Mg layers riding into subsequently deposited n-type layers. Mg concentration in the subsequent layers was lowered from ˜1 × 1018 cm-3 for a medium temperature growth at 950 °C to ˜1 × 1016 cm-3 for a low temperature growth at 700 °C via FME. The slope of the Mg concentration drop in the 700 °C FME sample was 20 nm/dec—the lowest ever demonstrated by MOCVD. For growth on Mg implanted GaN layers, the drop for a medium temperature regrowth at 950 °C was ˜10 nm/dec compared to >120 nm/dec for a high temperature regrowth at 1150 °C. This drop-rate obtained at 950 °C or lower was maintained even when the growth temperature in the following layers was raised to 1150 °C. A controlled silicon doping series using LT FME was also demonstrated with the lowest and highest achieved doping levels being 5 × 1016 cm-3 and 6 × 1019 cm-3, respectively.

  19. Nonparametric inference from the M/G/1 workload

    DEFF Research Database (Denmark)

    Hansen, Martin Bøgsted; Pitts, Susan M.

    2006-01-01

    Consider an M/G/1 queue with unknown service-time distribution and unknown traffic intensity ρ. Given systematically sampled observations of the workload, we construct estimators of ρ and of the service-time distribution function, and we study asymptotoic properties of these estimators....

  20. Nonparametric inference from the M/G/1 workload

    DEFF Research Database (Denmark)

    Hansen, Martin Bøgsted; Pitts, Susan M.

    Consider an M/G/1 queue with unknown service-time distribution and unknown traffic intensity $\\rho$. Given systematically sampled observations of the workload, we construct estimators of $\\rho$ and of the service-time distribution function, and we study asymptotic properties of these estimators....

  1. Lithium ion implantation effects in MgO (100)

    NARCIS (Netherlands)

    van Huis, MA; Fedorov, AV; van Veen, A; Labohm, F; Schut, H; Mijnarends, PE; Kooi, BJ; De Hosson, JTM; Triftshauser, W; Kogel, G; Sperr, P

    2001-01-01

    Single crystals of MgO (100) were implanted with 10(16) (6)Li ions cm(-2) at an energy of 30 keV. After ion implantation the samples were annealed isochronally in air at temperatures up to 1200K. After implantation and after each annealing step, the defect evolution was monitored with optical

  2. The effects of Mg incorporation and annealing temperature on the ...

    Indian Academy of Sciences (India)

    Home; Journals; Pramana – Journal of Physics; Volume 88; Issue 2. The effects of Mg incorporation and annealing temperature on the physicochemical properties and antibacterial activity against {\\it Listeria monocytogenes} of ZnO nanoparticles. NIMA SHADAN ALI ABDOLAHZADEH ZIABARI RAFIEH MERAAT KAMYAR ...

  3. Dosimetric properties of LIF:Mg,CuP+PTFE

    International Nuclear Information System (INIS)

    Gonzalez Martinez, P.R.; Azorin Nieto, J.; Ramirez Luna, A.

    1998-01-01

    The work presents the preparation method, as well as the characterization of the dosemeters of LiF;Mg,Cu+PTFE developed in the National Institute of Nuclear Investigations (ININ) Mexico, Among the carried out tests can mention, sensibility, detection threshold, equivalent of bottom, uniformity, reproducibility, dissipation, answer in function of the dose and kinetic parameters

  4. Atomistic simulations of Mg-Cu metallic glasses: Mechanical properties

    DEFF Research Database (Denmark)

    Bailey, Nicholas; Schiøtz, Jakob; Jacobsen, Karsten Wedel

    2004-01-01

    The atomistic mechanisms of plastic deformation in amorphous metals are far from being understood. We have derived potential parameters for molecular dynamics simulations of Mg-Cu amorphous alloys using the Effective Medium Theory. We have simulated the formation of alloys by cooling from the melt...

  5. Multiwavelength observations of the Type IIb supernova 2009mg

    DEFF Research Database (Denmark)

    Oates, S. R.; Bayless, A. J.; Stritzinger, M. D.

    2012-01-01

    -time temporal index of SN 2009mg, determined from 40 d post-explosion, is consistent with the decay rate of SN 1993J, but inconsistent with the decay of 56Co. This suggests leakage of γ-rays out of the ejecta and a stellar mass on the small side of the mass distribution. Our XRT non-detection provides an upper...

  6. Measurements of Narrow Mg II Associated Absorption Doublets with ...

    Indian Academy of Sciences (India)

    2016-01-27

    Jan 27, 2016 ... The measurement of the variations of absorption lines over time is a good method to study the physical conditions of absorbers. In this paper, we measure the variations of the line strength of 36 narrow Mg II2796, 2803 associated absorption doublets, which are imprinted on 31 quasar spectra with two ...

  7. Microwave absorption studies of MgB 2 superconductor

    Indian Academy of Sciences (India)

    Microwave absorption studies have been carried out on MgB2 superconductor using a standard X-band EPR spectrometer. The modulated low-field microwave absorption signals recorded for polycrystalline (grain size ∼ 10m) samples suggested the absence of weak-link character. The field dependent direct microwave ...

  8. Understanding Active Metal Reaction Kinetics with Cu–Mg ...

    Indian Academy of Sciences (India)

    magnesium metal (Mg(s)) in the cathode and chlorine (Cl2(g)) in the anode ... der acidic (pH ≤ 4) and basic (pH≥ 9) conditions, the oxide layer is broken and its .... and high ionic strength of the environment (such as sea water. ([Cl−] = from ...

  9. Soldering of Mg Joints Using Zn-Al Solders

    Science.gov (United States)

    Gancarz, Tomasz; Berent, Katarzyna; Skuza, Wojciech; Janik, Katarzyna

    2018-04-01

    Magnesium has applications in the automotive and aerospace industries that can significantly contribute to greater fuel economy and environmental conservation. The Mg alloys used in the automotive industry could reduce mass by up to 70 pct, providing energy savings. However, alongside the advantages there are limitations and technological barriers to use Mg alloys. One of the advantages concerns phenomena occurring at the interface when joining materials investigated in this study, in regard to the effect of temperature and soldering time for pure Mg joints. Eutectic Zn-Al and Zn-Al alloys with 0.05 (wt pct) Li and 0.2 (wt pct) Na were used in the soldering process. The process was performed for 3, 5, and 8 minutes of contact, at temperatures of 425 °C, 450 °C, 475 °C, and 500 °C. Selected, solidified solder-substrate couples were cross-sectioned, and their interfacial microstructures were investigated by scanning electron microscopy. The experiment was designed to demonstrate the effect of time, temperature, and the addition of Li and Na on the kinetics of the dissolving Mg substrate. The addition of Li and Na to eutectic Zn-Al caused to improve mechanical properties. Higher temperatures led to reduced joint strength, which is caused by increased interfacial reaction.

  10. Lines of MgI Detected in Solar Prominences

    Czech Academy of Sciences Publication Activity Database

    Heinzel, Petr; Kupryakov, Yu. A.; Schwartz, P.

    2016-01-01

    Roč. 40, č. 1 (2016), s. 87-91 ISSN 1845-8319. [Hvar Astrophysical Colloquium /14./. Hvar, 26.09.2016-30.09.2016] Institutional support: RVO:67985815 Keywords : prominences * limb-flare * MgI emession Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics

  11. Insulator layer formation in MgB2 SIS junctions

    International Nuclear Information System (INIS)

    Shimakage, H.; Tsujimoto, K.; Wang, Z.; Tonouchi, M.

    2005-01-01

    The dependence of current-voltage characteristics on thin film deposition conditions was investigated using MgB 2 /AlN/NbN SIS junctions. By increasing the substrate temperature in AlN insulator deposition, the current density decreased and the normal resistance increased. The results indicated that an additional insulator layer between the MgB 2 and AlN formed, either before or during the AlN deposition. The thickness of the additional insulator layer was increased with an increase in the AlN deposition temperature. From the dependence of current density on the thickness of AlN in low temperature depositions, the thickness of the additional insulator layer was estimated to be 1-1.5 nm when the AlN insulator was deposited from 0.14 to 0.7 nm. Moreover, with the current density of MgB 2 /AlN/MgB 2 SIS junctions, further insulator layer formation was confirmed

  12. Enhanced Optical Performance of BaMgAl

    NARCIS (Netherlands)

    Yin, L.J.; Dong, Juntao; Wang, Yinping; Zhang, Bi; Zhou, Zheng Yang; Jian, Xian; Wu, Mengqiang; Xu, Xin; van Ommen, J.R.; Hintzen, H.T.J.M.

    2016-01-01

    Many strategies have been adopted to improve thermal degradation of phosphors. Because of the stability and high transmittance of graphene, here we report a novel method of carbon coating on BaMgAl10O17:Eu2+ (BAM) phosphor particles through chemical vapor

  13. Controlled release of ibuprofen using Mg Al LDH nano carrier

    Science.gov (United States)

    Dasgupta, Sudip

    2017-08-01

    In the present study, NSAID (non-steroidal anti-inflammatory drugs) such as ibuprofen in anionic form has been intercalated in-situ into the interlayer space of Mg Al LDH nanoparticle during co-precipitation of hydroxides. LDH nanohybrids are characterized by XRD, FTIR and UV spectroscopy. Mg1-xAlx(NO3)x(OH)2.nH2O nanoparticles were synthesized using co-precipitation method from an aqueous solution of Mg(NO3)2.6H2O and Al(NO3)3.9H2O. Ibuprofen was intercalated in inter layer space of Mg-Al LDH during coprecipitation of drug LDH conjugate in nitrogen atmosphere. The nanopowders synthesised were in the size range between 25 to 90 nm with an average particle size of 55 nm. XRD analysis proved that there is an increase in d003 spacing from 7.89 Å for pristine LDH to 14.71 Å for ibuprofen intercalated LDH due to the intercalation of bigger ibuprofen molecule in the interlayer space of LDH. FTIR analysis showed hydroxyl and carbonyl stretching of ibuprofen in LDH-IBU sample confirming the intercalation of ibuprofen in the interlayer structure of LDH. The drug release study in phosphate buffer solution at pH 7.4 using UV-Vis spectroscopy demonstrated that 50 % drug molecules were released in 15 hours and more than 85 % release was achieved after 36 hours.

  14. A randomized comparison of daunorubicin 90 mg/m2 vs 60 mg/m2 in AML induction

    DEFF Research Database (Denmark)

    Burnett, A. K.; Russell, N. H.; Hills, R. K.

    2015-01-01

    Modifying induction therapy in acute myeloid leukemia (AML) may improve the remission rate and reduce the risk of relapse, thereby improving survival. Escalation of the daunorubicin dose to 90 mg/m(2) has shown benefit for some patient subgroups when compared with a dose of 45 mg/m(2), and has been...... = .15). In an exploratory subgroup analysis, there was no subgroup that showed significant benefit, although there was a significant interaction by FLT3 ITD mutation. This trial is registered at http://www.isrctn.com as #ISRCTN55675535....

  15. Band structure of semiconductor compounds of Mg sub 2 Si and Mg sub 2 Ge with strained crystal lattice

    CERN Document Server

    Krivosheeva, A V; Shaposhnikov, V L; Krivosheev, A E; Borisenko, V E

    2002-01-01

    The effect of isotopic and unaxial deformation of the crystal lattice on the electronic band structure of indirect band gap semiconductors Mg sub 2 Si and Mg sub 2 Ge has been simulated by means of the linear augmented plane wave method. The reduction of the lattice constant down to 95 % results in a linear increase of the direct transition in magnesium silicide by 48%. The stresses arising under unaxial deformation shift the bands as well as result in splitting of degenerated states. The dependence of the interband transitions on the lattice deformation is nonlinear in this case

  16. Luna 24 ferrobasalt as a low-Mg primary melt

    International Nuclear Information System (INIS)

    Norman, M.; Ryder, G.

    1980-01-01

    Luna 24 very-low titanium (VLT) ferrobasalts, metabasalts, brown glasses and impact melts form a tight compositional cluster with no gradation to other groupings postulated for the Luna 24 core components. This suggests that the Luna 24 VLT ferrobasalt was extruded as a liquid of its own composition and was not derived by fractional crystallization from a more magnesian parent in a surface flow. Furthermore, the characteristics of the core lithologies are not easily visualized as components of such a differential flow, e.g. brown glasses. Gravitative settling models purporting to demonstrate the validity of the flow differentiation model are merely permissive. Subsurface fractionation requires that plagioclase, not olivine, be the liquidus phase. The high-Mg component in the Luna 24 core can be constrained, though not identified, chemically, and it has neither the major element, trace element, isotopic, nor mineralogical characteristics required of a possible parent to the Luna 24 VLT ferrobasalt. Thus models of fractionation lack a physical expression of the less differentiated compositions, contrary to the belief that the high-Mg component in the core is the parent material. The Luna 24 VLT ferrobasalt is probably a primary low-Mg melt from a plagioclase-bearing source region, and may have undergone little or no fractionation prior to eruption. Such a model is compatible with, and suggested by, chemical and experimental data. Caution against posulating that all Mg-poor melts are fractionated products, based on terrestrial models, is advised. The terrestrial oceanic situation of 'primary melts' with similar Mg/Fe is probably not valid for the Moon. (Auth.)

  17. On heavy carbon doping of MgB2

    International Nuclear Information System (INIS)

    Kasinathan, Deepa; Lee, K.-W.; Pickett, W.E.

    2005-01-01

    Heavy carbon doping of MgB 2 is studied by first principles electronic structure studies of two types, an ordered supercell (Mg(B 1-x C x ) 2 , x 0.0833) and also the coherent potential approximation method that incorporates effects of B-C disorder. For the ordered model, the twofold degenerate σ-bands that are the basis of the high temperature superconductivity are split by 60 meV (i.e. 7 meV/% C) and the σ Fermi cylinders contain 0.070 holes/cell, compared to 0.11 for MgB 2 . A virtual crystal treatment tends to overestimate the rate at which σ holes are filled by substitutional carbon. The coherent potential approximation (CPA) calculations give the same rate of band filling as the supercell method. The occupied local density of states of C is almost identical to that of B in the upper 2 eV of the valence bands, but in the range -8 eV to -2 eV, C has a considerably larger density of states. The calculations indicate that the σ Fermi surface cylinders pinch off at the zone center only above the maximum C concentration x ∼ 0.10. These results indicate that Mg(B 1-x C x ) 2 as well as Mg 1-x Al x B 2 is a good system in which to study the evolution of the unusual electron-phonon coupling character and strength as the crucial σ hole states are filled

  18. Frovatriptan 2.5 mg plus dexketoprofen (25 mg or 37.5 mg) in menstrually related migraine. Subanalysis from a double-blind, randomized trial.

    Science.gov (United States)

    Allais, G; Bussone, G; Tullo, V; Cortelli, P; Valguarnera, F; Barbanti, P; Sette, G; D'Onofrio, F; Curone, M; Benedetto, C

    2015-01-01

    The purpose of this article is to investigate the efficacy and safety of frovatriptan plus dexketoprofen 25 or 37.5 mg (FroDex25 or FroDex37.5, respectively) compared to that of frovatriptan 2.5 mg (Frova) in menstrually related migraine (MRM). The aim of this article is to analyze a subgroup of 76 women who treated an MRM attack in this multicenter, randomized, double-blind, parallel-group study. The primary end-point was the proportion of patients who were pain free (PF) at two hours. Secondary end-points included pain-relief (PR) at two hours and 48 hours sustained pain free (SPF). PF rates at two hours were 29% under Frova, 48% under FroDex25 and 64% under FroDex37.5 (p dexketoprofen produced higher PF rates at two hours compared to Frova while maintaining efficacy at 48 hours. Tolerability profiles were comparable. © International Headache Society 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

  19. Book Review | Dunn-Coetzee | Journal of Student Affairs in Africa

    African Journals Online (AJOL)

    Roberts, Dennis C. & Komives, Susan R. (Eds.) (2016). Enhancing Student Learning and Development in Cross- Border Higher Education. San Francisco: Jossey-Bass. Full Text: EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT · AJOL African Journals Online.

  20. Tribute to Michael Dunn for his dedication and contribution to proteomics and stem cell focus

    Czech Academy of Sciences Publication Activity Database

    Kovářová, Hana; Gadher, S. J.

    2016-01-01

    Roč. 16, č. 22 (2016), s. 2840-2841 ISSN 1615-9853 R&D Projects: GA MŠk(CZ) LO1609 Institutional support: RVO:67985904 Keywords : proteomics Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 4.041, year: 2016

  1. Global Distribution of Plant-Extractable Water Capacity of Soil (Dunne)

    Data.gov (United States)

    National Aeronautics and Space Administration — Plant-extractable water capacity of soil is the amount of water that can be extracted from the soil to fulfill evapotranspiration demands. This data set provides an...

  2. The role of Mg interface layer in MgO magnetic tunnel junctions with CoFe and CoFeB electrodes

    Directory of Open Access Journals (Sweden)

    Hyunsoo Yang

    2012-03-01

    Full Text Available The tunneling spin polarization (TSP is directly measured from reactively sputter deposited crystalline MgO tunnel barriers with various CoFe(B compositions using superconducting tunneling spectroscopy. We find that the Mg interface layer thickness dependence of TSP values for CoFeB/Mg/MgO junctions is substantially different from those for CoFe/Mg/MgO especially in the pre-annealed samples due to the formation of boron oxide at the CoFeB/MgO interface. Annealing depletes boron at the interface thus requiring a finite Mg interface layer to prevent CoFeOx formation at the CoFeB/MgO interface so that the TSP values can be optimized by controlling Mg thickness.

  3. Uncovering the Local Magnesium Environment in the Metal–Organic Framework Mg 2 (dobpdc) Using 25 Mg NMR Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Jun; Blaakmeer, E. S. Merijn [Institute; Lipton, Andrew S. [Environmental; McDonald, Thomas M.; Liu, Yifei Michelle; Smit, Berend [Laboratory; Long, Jeffrey R. [Materials; Kentgens, Arno P. M. [Institute; Reimer, Jeffrey A. [Materials

    2017-09-06

    The incorporation of N,N'-dimethylethylenediamine into an expanded MOF-74 framework has yielded a material (mmen-Mg2(dobpdc)) exhibiting “step-shaped” CO2 adsorption isotherms. The coordination of mmen at the Mg open metal center is essential for the unique cooperative adsorption mechanism elucidated for this material. Despite its importance for carbon capture, there is as yet no experimental structure determination available for the underlying metal– organic framework Mg2(dobpdc). Our 25Mg solid-state NMR data unravel the local Mg environments in several Mg2(dobpdc) samples, unambiguously confirming the formation of fivecoordinate Mg centers in the activated material and six-coordinate Mg centers in the solvent- or diamine-loaded samples, such as mmen-Mg2(dobpdc). A fraction of the Mg centers are locally disordered due to the framework deformation accompanied by the guest distributions and dynamics.

  4. Research on MgLi and a specifically German consequence. MgLi-Forschung und ihre spezifisch deutsche Konsequenz

    Energy Technology Data Exchange (ETDEWEB)

    Hehmann, F [Office National d' Etudes et de Recherches Aerospatiales (ONERA), 92 - Chatillon (France)

    1994-05-01

    When light weight structural applications are of prime concern, magnesium cannot be ignored. When magnesium is of prime concern, of course, the research cannot be ignored, either. Since there is not much to be ignored (or not), however, it is the research on MgLi that takes the lead in the German press. ''Rock-solid as Kruppstahl'' was it meant to be, though MgLi-alloys soften quite appreciable already at ambient temperature. A hydrogen treatment of the MgLi melt was the phenomenon that was naturally astounded. In the meantime, however, it became very tranquilly around the contest for the selection of the species from the ''MgLi-Born''. Has the hot air already escaped Warm wind is not bad in each case. Daily discipline, however, has scaled ever since with the natural beauty of the more concrete results by working. What follows is an article that looks upon this particular German variant at the ''histoire parallele'' in the field of metallic innovations as well as upon the sound base of such deliberately outbalanced renaissances. (orig.)

  5. Catalytically Enhanced Hydrogen Sorption in Mg-MgH2 by Coupling Vanadium-Based Catalyst and Carbon Nanotubes

    Directory of Open Access Journals (Sweden)

    Atikah Kadri

    2015-06-01

    Full Text Available Mg (MgH2-based composites, using carbon nanotubes (CNTs and pre-synthesized vanadium-based complex (VCat as the catalysts, were prepared by high-energy ball milling technique. The synergistic effect of coupling CNTs and VCat in MgH2 was observed for an ultra-fast absorption rate of 6.50 wt. % of hydrogen per minute and 6.50 wt. % of hydrogen release in 10 min at 200 °C and 300 °C, respectively. The temperature programmed desorption (TPD results reveal that coupling VCat and CNTs reduces both peak and onset temperatures by more than 60 °C and 114 °C, respectively. In addition, the presence of both VCat and CNTs reduces the enthalpy and entropy of desorption of about 7 kJ/mol H2 and 11 J/mol H2·K, respectively, as compared to those of the commercial MgH2, which ascribe to the decrease of desorption temperature. From the study of the effect of CNTs milling time, it is shown that partially destroyed CNTs (shorter milling time are better to enhance the hydrogen sorption performance.

  6. Theoretical and experimental study of the intrinsic physical properties of the Mg-MgH{sub 2} system

    Energy Technology Data Exchange (ETDEWEB)

    Puszkiel, Julian A.; Gervasoni, Juana L. [Centro Atomico Bariloche (CAB) - Instituto Balseiro (IB) - Comision Nacional de Energia Atomica (CNEA), Av. Bustillo km 9.5, R8402 AGP S.C. de Bariloche (Argentina)

    2010-06-15

    Due to the fundamental problems of energy source limitations and environmental pollution, hydrogen has become an attractive clean energy source for the future. Despite the fact that the incentive to switch to a hydrogen economy has increased, there are many problems which must be solved. One of the main unsolved issues is hydrogen storage. Among the potential materials to store hydrogen in a safe way, Mg has drawn interest owing to its high hydrogen capacity (7.6 wt%), light weight and low cost. In order to improve the hydrogen capacity of potential storage materials such as Mg, it is important to understand the site preferences of hydrogen atoms in the metal. Such behavior depends mainly on the screening charge density ({delta}n(r)) of the system proton-metallic host, from which all the physical macroscopic properties (viz. V{sub H}, {delta}H{sub S}, B, etc.) and IDOS are determined. In the present work we study the interaction between a proton and Mg as host metal via ab initio calculations, using the Jellium model, based on the density-functional theory (DFT). The macroscopic properties are determined and compared with experimental results and values found in the bibliography. Furthermore, in order to obtain information about the electronic distribution of hydrogen and the nature of the Mg-H bonding, the IDOS is described. (author)

  7. Discovery of the shape coexisting 0+ state in 32Mg

    International Nuclear Information System (INIS)

    Wimmer, Kathrin

    2010-01-01

    The evolution of shell structure in exotic nuclei as a function of proton (Z) and neutron (N) number is currently at the center of many theoretical and experimental investigations. It has been realized that the interaction of the last valence protons and neutrons, in particular the monopole component of the residual interaction between those nucleons, can lead to significant shifts in the single-particle energies, leading to the collapse of classic shell closures and the appearance of new shell gaps. The ''Island of Inversion'' around 32 Mg, which is one of the most studied phenomena in the nuclear chart, is a well known example for such changes in nuclear structure. In this region of neutron-rich nuclei around the magic number N=20 strongly deformed ground states in Ne, Na, and Mg isotopes have been observed. Due to the reduction of the N=20 shell gap quadrupole correlations can enable low-lying deformed 2p-2h intruder states from the fp-shell to compete with spherical normal neutron 0p-0h states of the sd-shell. In this situation the promotion of a neutron pair across the N=20 gap can result in deformed intruder ground states. Consequentially the two competing configurations can lead to the coexistence of spherical and deformed 0 + states in the neutron rich nuclei 30,32 Mg. In this work the shape coexistence in 32 Mg was studied by a two neutron transfer reaction at the REX-ISOLDE facility (CERN). The two neutron transfer reaction with a 30 Mg beam involved for the first time the use of a radioactive tritium target in combination with a radioactive heavy ion beam. Light charged particles emitted from the target were detected and identified by the T-REX particle detector while γ-rays were detected by the MINIBALL Germanium detector array. The shape of the angular distribution of the protons allows to unambiguously determine the angular momentum transfer ΔL of the reaction and thus to identify the 0 + states. The analysis of excitation energies and angular

  8. Recovery of SO2 and MgO from By-Products of MgO Wet Flue Gas Desulfurization.

    Science.gov (United States)

    Yan, Liyun; Lu, Xiaofeng; Wang, Quanhai; Guo, Qiang

    2014-11-01

    An industrial demonstration unit using natural gas as a heat source was built to calcine the by-products of MgO wet flue gas desulfurization from power plants; influencing factors on the SO 2 content in calciner gas were comprehensively analyzed; and an advantageous recycling condition of MgO and SO 2 from by-products was summarized. Results showed that the SO 2 content in the calciner gas was increased by more than 10 times under a lower excess air coefficient, a higher feed rate, a lower crystal water in by-products, and a higher feed port position. For the tests conducted under the excess air coefficient above and below one, the effect of the furnace temperature on the SO 2 content in the calciner gas was reversed. Results of activity analysis indicate that particles of MgO generated under the calcination temperature of 900-1,000°C had a high activity. In contrast, due to the slight sintering, MgO generated under the calcination temperature of 1,100°C had a low activity. To recycle SO 2 as well as MgO, a temperature range of 900-927°C for TE103 is proposed. These studies will prompt the desulfurization market diversification, reduce the sulfur's dependence on imports for making sulfuric acid, be meaningful to balance the usage of the natural resource in China, and be regarded as a reference for the development of this technology for other similar developing countries.

  9. The impact of Mg contents on Sr partitioning in benthic foraminifers

    NARCIS (Netherlands)

    Mewes, Antje; Langer, Gerald; Reichart, Gert Jan; de Nooijer, L.J.; Nehrke, Gernot; Bijma, Jelle

    2015-01-01

    Foraminiferal calcite Mg/Ca (Mg/CaCC) is used in paleoceanographic studies to reconstruct temperature. Furthermore, the Mg/CaCC is influenced by different seawater Mg/Ca (Mg/CaSW). Foraminiferal calcite Sr/Ca (Sr/CaCC) can potentially be used to reconstruct Sr/Ca ratios of seawater (Sr/CaSW). As

  10. Stability of a formulation of zidovudine 300 mg tablets

    International Nuclear Information System (INIS)

    Ibannez Calvo, Sergio; Garcia Penna, Caridad Margarita; Leon Rodriguez, Rafael

    2010-01-01

    Authors developed a validation of analytical method by high-performance liquid applicable to stability study of Zidovudine (300 mg tablets). The validated analytical method was linear, specific and exact. Above mentioned study was developed determing its expiry date. This study was conducted by fixed life and of accelerated stability methods by high-performance liquid chromatography, validated in Drugs Research and Development Center (Havana, Cuba). Fixed life study was conducted during 24 months at room temperature whereas the accelerated stability study was conducted exposing the product to light influence and humidity during three months and to temperature during 6 months. Zidovudine formula (300 mg tablets) fulfilled the quality specifications described in Pharmacopeia. After 24 months results of stability study by fixed life showed that product maintained the parameters determining its quality during that period and in accelerated studies there was not a significant degradation of product. Two years was established as expiry date in above mentioned conditions

  11. Stannate conversion coatings on Mg-8Li alloy

    International Nuclear Information System (INIS)

    Yang Lihui; Zhang Milin; Li Junqing; Yu Xiang; Niu Zhongyi

    2009-01-01

    The stannate conversion coatings (SnCC) on Mg-8Li alloy were investigated by simple immersion method. The surface morphology and composition were studied by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and X-ray diffraction spectroscopy (XRD) techniques. The corrosion resistance was assessed by means of potentiodynamic polarization measurements and electrochemical impedance spectra (EIS). The effects of time of a stannate bath on the quality of stannate conversion coatings were investigated by SEM and EIS. It was found that the coating particles were mainly composed of hemispherical particles MgSnO 3 .3H 2 O. A comparison of results revealed the coating treated for 60 min exhibited the most uniform, dense and corrosion-resistant

  12. Active Protection of an MgB2 Test Coil

    Science.gov (United States)

    Park, Dong Keun; Hahn, Seungyong; Bascuñán, Juan; Iwasa, Yukikazu

    2011-01-01

    This paper presents results of a study, experimental and computational, of a detect-and-activate-the-heater protection technique applied to a magnesium diboride (MgB2) test coil operated in semi-persistent mode. The test coil with a winding ID of 25 cm and wound with ~500-m long reacted MgB2 wire was operated at 4.2 K immersed in a bath of liquid helium. In this active technique, upon the initiation of a “hot spot” of a length ~10 cm, induced by a “quench heater,” a “protection heater” (PH) of ~600-cm long planted within the test coil is activated. The normal zone created by the PH is large enough to absorb the test coil’s entire initial stored energy and still keeps the peak temperature within the winding below ~260 K. PMID:22081754

  13. HRTEM investigation of orthorhombic phase in Mg-PSZ

    International Nuclear Information System (INIS)

    Liu, Z.W.; Spargo, A.E.C.; Hannink, R.H.J.

    1997-01-01

    Tetragonal, orthorhombic and monoclinic phases are only slight distortions of the cubic structure. Due to minor differences in unit cell parameters it is difficult to distinguish these phases only by high resolution images. However, using high resolution transmission electron microscopy (HRTEM) observation in combination with image simulation and digital Fourier transformation of HRTEM images, it was found that one tetragonal precipitate can be transformed to several orthorhombic domains with different orientations in MgO-partially-stabilized zirconia (Mg-PSZ). The lattice correspondence between two adjacent orthorhombic domains is such that their b axes are parallel, while their a axes are perpendicular to each other. Also it was found that cubic ZrO 2 could be transformed to orthorhombic ZrO 2 . 8 refs., 1 tab., 4 figs

  14. Rocksalt MgS solar blind ultra-violet detectors

    Directory of Open Access Journals (Sweden)

    Ying-Hoi Lai

    2012-03-01

    Full Text Available Studies using in-situ Auger electron spectroscopy and reflection high energy electron diffraction, and ex-situ high resolution X-ray diffraction and electron backscatter diffraction reveal that a MgS thin film grown directly on a GaAs (100 substrate by molecular beam epitaxy adopts its most stable phase, the rocksalt structure, with a lattice constant of 5.20 Å. A Au/MgS/n+-GaAs (100 Schottky-barrier photodiode was fabricated and its room temperature photoresponse was measured to have a sharp fall-off edge at 235 nm with rejection of more than three orders at 400 nm and higher than five orders at 500 nm, promising for various solar-blind UV detection applications.

  15. Mg2FeH6 Synthesis Efficiency Map

    Directory of Open Access Journals (Sweden)

    Katarzyna Witek

    2018-02-01

    Full Text Available The influences of the processing parameters on the Mg2FeH6 synthesis yield were studied. Mixtures of magnesium hydride (MgH2 and iron (Fe were mechanically milled in a planetary ball mill under argon for 0.5-, 1-, 2- and 3-h periods and subsequently sintered at temperatures from 300–500 ∘ C under hydrogen. The reaction yield, phase content and hydrogen storage properties of the received materials were investigated. The morphologies of the powders after synthesis were studied by SEM. The synthesis effectiveness map was presented. The obtained results prove that synthesis parameters, such as the milling time and synthesis temperature, greatly influence the reaction yield and material properties and show that extended mechanical milling may not be beneficial to the reaction efficiency.

  16. Luminescence characteristics of Mg2SiO4:Nd

    International Nuclear Information System (INIS)

    Indira, P.; Subrahmanyam, R.V.; Murthy, K.V.R.

    2011-01-01

    Thermoluminescence (TL) properties of Magnesium Ortho silicate (2:1) Mg 2 SiO 4 doped with various concentrations of rare earth (Nd) have been studied. The phosphor material were prepared using standard solid state reaction technique and heated specimens at 1100 ± 20 deg C for two hours. 4% Ammonium chloride was used as flux. The received material was grinded in an agate mortar and pestle. The TL exhibited by the Mg 2 SiO 4 with varying concentration of Nd is interesting in nature. It is interesting to note but as the concentration of Nd increases the peak around 125 deg C TL peak intensity increases. But the hump around 200 deg C resolved as TL peak at 253 deg C with high intensity. (author)

  17. AMOC studies of positronium in fine MgO powder

    International Nuclear Information System (INIS)

    Waeyenberge, B. van; Dauwe, C.

    2001-01-01

    A first set of AMOC spectra on fine powdered MgO were measured at the Stuttgart relativistic positron beam facility. A special AMOC spectrometer was set up in order to determine the long lifetimes of ortho-positronium in the powder cavities. The spectra were taken on pellets of pressed powder in air and in an oxygen atmosphere to ensure ortho- to para-positronium conversion. An analysis of the data is made in the light of previous lifetime measurements on MgO. Here the lifetime spectrum was fitted with an age dependent lifetime describing the slow thermalisation of epithermal ortho-positronium between the powder grains. Based on the lifetime spectrum of the integrated AMOC spectra the data could not discriminate between a 5-component model and a model including slow positronium thermalisation. On the other hand, analysis of the age dependent line shape parameter shows better variances for a thermalisation model. (orig.)

  18. AMOC studies of positronium in fine MgO powder

    Energy Technology Data Exchange (ETDEWEB)

    Waeyenberge, B. van; Dauwe, C. [Ghent Univ. (Belgium). Dept. of Subatomic and Radiation Physics; Stoll, H. [Max-Planck-Institut fuer Metallforschung, Stuttgart (Germany)

    2001-07-01

    A first set of AMOC spectra on fine powdered MgO were measured at the Stuttgart relativistic positron beam facility. A special AMOC spectrometer was set up in order to determine the long lifetimes of ortho-positronium in the powder cavities. The spectra were taken on pellets of pressed powder in air and in an oxygen atmosphere to ensure ortho- to para-positronium conversion. An analysis of the data is made in the light of previous lifetime measurements on MgO. Here the lifetime spectrum was fitted with an age dependent lifetime describing the slow thermalisation of epithermal ortho-positronium between the powder grains. Based on the lifetime spectrum of the integrated AMOC spectra the data could not discriminate between a 5-component model and a model including slow positronium thermalisation. On the other hand, analysis of the age dependent line shape parameter shows better variances for a thermalisation model. (orig.)

  19. Superconductivity near ferromagnetism in MgCNi3

    International Nuclear Information System (INIS)

    Rosner, H.; Weht, R.; Johannes, M.; Pickett, W.E.; Tosatti, E.

    2001-06-01

    Superconductivity and ferromagnetism have been believed to be incompatible over any extended temperature range until certain specific examples - RuSr 2 GdCu 2 O 8 and UGe 2 - have arisen in the past 2-3 years. The discovery of superconductivity above 8 K in MgCNi 3 , which is primarily the ferromagnetic element Ni and is strongly exchange-enhanced, provides a probable new and different example. This compound is shown here to be near ferromagnetism, requiring only hole-doping by 12% substitution of Mg by Na or Li. This system will provide the means to probe coupling, and possible coexistence, of these two forms of collective behavior without the requirement of pressure. (author)

  20. Observation of pseudogap in MgB2

    Science.gov (United States)

    Patil, S.; Medicherla, V. R. R.; Ali, Khadiza; Singh, R. S.; Manfrinetti, P.; Wrubl, F.; Dhar, S. K.; Maiti, Kalobaran

    2017-11-01

    We investigate the electronic structure of a specially prepared highly dense conventional high temperature superconductor, MgB2, employing high resolution photoemission spectroscopy. The spectral evolution close to the Fermi energy is commensurate to BCS descriptions as expected. However, the spectra in the wider energy range reveal the emergence of a pseudogap much above the superconducting transition temperature indicating an apparent departure from the BCS scenario. The energy scale of the pseudogap is comparable to the energy of the E2g phonon mode responsible for superconductivity in MgB2 and the pseudogap can be attributed to the effect of electron-phonon coupling on the electronic structure. These results reveal a scenario of the emergence of the superconducting gap within an electron-phonon coupling induced pseudogap and have significant implications in the study of high temperature superconductors.

  1. An accurate potentiometric titration of 5-25 mg uranium

    International Nuclear Information System (INIS)

    Slanina, J.; Bakker, F.; Lingerak, W.A.

    1976-01-01

    A potentiometric titration of 5 to 25 mg uranium is described. Sulphamic and phosphoric acid are added to the sample (volume 1 ml), U VI is reduced to U IV by Fe 2+ and the excess of Fe 2+ is oxidized by a mixture of nitric acid, sulphamic acid and ammonium molybdate; vanadyl sulphate is added to ensure a sharp end-point of the titration. The resultant U IV is titrated automatically with 0.02500N potassiumdichromate using a platinum indicator electrode. The automatic titration is performed both with a commercial titrator (Mettler) and with an R.C.N. titrator which waits after each addition until the equilibrium is reached. Using the Mettler titrator an accuracy of 0.05% relative was reached. The R.C.N. setpoint titrator gave results with an accuracy of 0.04% relative at the 20-mg U level. Each titration takes 5 to 7 min. (author)

  2. Study of the 50 mg Propylthiouracil tablets stability

    International Nuclear Information System (INIS)

    Valdes Bendoyro, Maria Olga; Garcia Penna, Caridad Margarita; Lugones Fernandez, Juan

    2010-01-01

    Authors developed a stability study of 50 mg Propylthiouracil tablets and determination of its expiry date. This study was conducted by fixed life methods and of accelerated stability by high-performance liquid chromatography, validated in Drugs Research and Development Center. Fixed life study was conducted during 24 months at room temperature; whereas the accelerated stability study was conducted exposing the product to light influence, humidity and temperature; during 3 months a analysis was performed for the two first ones and over 6 months in the case of temperature study. Propylthiouracil formula (50 mg tablets) fulfilled the quality specifications described in Pharmacopeia. Results of stability study by fixed life after 24 months showed that thr product maintain the parameter determining its quality during this period, and in the accelerated studies there was not a significant degradation of product. Two years was the expity date established in above mentioned conditions

  3. Investigation of pinning in MgB2 superconductors

    International Nuclear Information System (INIS)

    Mohammad, S.; Reissner, M.; Steiner, W.; Bauer, E.; Giovannini, M.

    2006-01-01

    Full text: The pinning behaviour of bulk MgB 2 superconductors is peculiar in many respects. Pinning seems to be stronger than in classical high T C materials and there seems to be no weak link problem in these compounds, giving hope to produce bulk samples and wires with current densities appropriate for technical applications. But, although many studies concerning the pinning behaviour in this compound appeared in recent years, the results are still contradictory. In the present work we present results of an investigation of the pinning behaviour by magnetic relaxation measurements of three MgB 2 samples: a pure one, a sample with 8 at% Al substitution and a sample with 10 wt% of SiC admixture. A comparison of different analyses methods is given. (author)

  4. Secondary precipitation in an Al-Mg-Si-Cu alloy

    International Nuclear Information System (INIS)

    Buha, J.; Lumley, R.N.; Crosky, A.G.; Hono, K.

    2007-01-01

    Interruption of a conventional T6 heat treatment at 177 deg. C for the Al-Mg-Si-Cu alloy 6061 after a short period of time (20 min), by inserting a dwell period at a lower temperature (e.g. 65 deg. C), promotes secondary precipitation of Guinier-Preston (GP) zones. As a consequence, a much greater number of precursors to the β'' precipitates are produced so that a finer and denser dispersion of this phase is formed when T6 ageing is resumed. This change in microstructure causes significant and simultaneous improvements in tensile properties and fracture toughness. Secondary precipitation of GP zones occurs through a gradual evolution of a large number of Mg-Si(-Cu)-vacancy co-clusters formed during the initial ageing at 177 deg. C. The precise mechanism of secondary precipitation has been revealed by three-dimensional atom probe microscopy supplemented by transmission electron microscopy and differential scanning calorimetry

  5. Microstructure and hydrogen sorption kinetics of Mg nanopowders with catalyst

    International Nuclear Information System (INIS)

    Revesz, A.; Fatay, D.; Spassov, T.

    2007-01-01

    MgH 2 powders were ball-milled with and without catalysts (Nb 2 O 5 ) under hydrogen in a high-energy mill for 10 h. Morphological, structural and microstructural characterization of the nanocomposites, including particle and crystallite size distribution were carried out before and after hydrogen absorption. In order to study the above-mentioned microstructural parameters imaging and X-ray scattering techniques (high-resolution X-ray diffractometry) have been employed. The effect of the particle and grain size on the hydriding/dehydriding kinetics of ball-milled MgH 2 + catalyst powders was analyzed. The grain and particle size reduction enhances substantially the hydriding/dehydriding

  6. Luminescence of color centers in MgF2 crystals

    International Nuclear Information System (INIS)

    Vakhidov, Sh.A.; Nuritdinov, I.; Musaeva, M.A.

    1999-01-01

    The photoluminescence characteristics of the proper radiation color centers of the MgF 2 crystals are studied. The samples were irradiated by the 60 Co source γ-rays up to the dose 10 7 Gy. The bands with the maxima in the area of 420, 460, 550 and 620 nm were identified, which are excited correspondingly in the bands with the maxima of 370, 320, 410 and 480 nm

  7. Study of the $\\beta$-decay of $^{20}$Mg

    CERN Multimedia

    Cederkall, J A; Riisager, K; Garcia borge, M J; Madurga flores, M; Jonson, B N G; Fynbo, H O U; Koldste, G T; Giles, T J; Nilsson, T; Perea martinez, A

    We propose to perform a detailed study of the $\\beta$-decay of the dripline nucleus $^{20}$Mg. This will provide important information on resonances in $^{20}$Na relevant for the astrophysical rp-process as well as improved information for detailed comparison with state-of-the-art Shell-Model calculations and for comparison with the mirror $\\beta$-decay of $^{20}$O.

  8. Tetragonal to orthorhombic transformation in Mg-PSZ

    International Nuclear Information System (INIS)

    Liu, Z.W.; Spargo, A.E.C.; Hannink, R.H.J.; Drennan, J.

    1997-01-01

    The phase transformation from tetragonal to orthorhombic in MgO-partially-stabilized zirconia has been investigated by using high resolution transmission electron microscopy (HRTEM). Evidences are given to show that orthorhombic ZrO 2 frequently observed in transmission electron microscopy (TEM) thin foil studies was induced by dimpling and polishing during the specimen preparation. It was also found that the orthorhombic to monoclinic transformation was less sensitive to stress that the tetragonal to monoclinic transformation. 20 refs., 1 tab., 8 figs

  9. Thermodynamic modeling of the Mg-Al-Ca system

    Energy Technology Data Exchange (ETDEWEB)

    Janz, A.; Groebner, J. [Clausthal University of Technology, Institute of Metallurgy, Robert-Koch-Str. 42, D-38678 Clausthal-Zellerfeld (Germany); Cao, H.; Zhu, J.; Chang, Y.A. [Department of Materials Science and Engineering, University of Wisconsin, 1509 University Ave., Madison, WI 53706 (United States); Schmid-Fetzer, R. [Clausthal University of Technology, Institute of Metallurgy, Robert-Koch-Str. 42, D-38678 Clausthal-Zellerfeld (Germany)], E-mail: schmid-fetzer@tu-clausthal.de

    2009-02-15

    A thermodynamic model has been developed that provides a quantitative description for a wide area of the Mg-Al-Ca system. All available experimental data plus new key experiments using differential scanning calorimetry/differential thermal analysis have been considered to create a dataset which reproduces the primary crystallizing phases, the extensive ternary solubilities of binary phases and the ternary C36 Laves phase. This enables validated thermodynamic calculations in various areas of this ternary system.

  10. Substrate and Mg doping effects in GaAs nanowires

    Directory of Open Access Journals (Sweden)

    Perumal Kannappan

    2017-10-01

    Full Text Available Mg doping of GaAs nanowires has been established as a viable alternative to Be doping in order to achieve p-type electrical conductivity. Although reports on the optical properties are available, few reports exist about the physical properties of intermediate-to-high Mg doping in GaAs nanowires grown by molecular beam epitaxy (MBE on GaAs(111B and Si(111 substrates. In this work, we address this topic and present further understanding on the fundamental aspects. As the Mg doping was increased, structural and optical investigations revealed: i a lower influence of the polytypic nature of the GaAs nanowires on their electronic structure; ii a considerable reduction of the density of vertical nanowires, which is almost null for growth on Si(111; iii the occurrence of a higher WZ phase fraction, in particular for growth on Si(111; iv an increase of the activation energy to release the less bound carrier in the radiative state from nanowires grown on GaAs(111B; and v a higher influence of defects on the activation of nonradiative de-excitation channels in the case of nanowires only grown on Si(111. Back-gate field effect transistors were fabricated with individual nanowires and the p-type electrical conductivity was measured with free hole concentration ranging from 2.7 × 1016 cm−3 to 1.4 × 1017 cm−3. The estimated electrical mobility was in the range ≈0.3–39 cm2/Vs and the dominant scattering mechanism is ascribed to the WZ/ZB interfaces. Electrical and optical measurements showed a lower influence of the polytypic structure of the nanowires on their electronic structure. The involvement of Mg in one of the radiative transitions observed for growth on the Si(111 substrate is suggested.

  11. Obtention of Al-Mg alloys of porous morphology

    International Nuclear Information System (INIS)

    Barragan V, J.; Zamora R, L.; Sandoval J, A.R.; Iturbe G, J.L.

    2006-01-01

    With the objective of using it as fuel cell, a Mg 25 AI alloy of porous morphology was obtained. The material it was hydrogenates at 200 C by different time. It was analyzed by Scanning Electron Microscopy SEM and X-ray diffraction, XRD. Those XRD diffractographs present peaks run toward the origin, that which indicates a volume increase of the unitary cell by effect of the hydrogen absorption. (Author)

  12. Flexible MgO Barrier Magnetic Tunnel Junctions.

    Science.gov (United States)

    Loong, Li Ming; Lee, Wonho; Qiu, Xuepeng; Yang, Ping; Kawai, Hiroyo; Saeys, Mark; Ahn, Jong-Hyun; Yang, Hyunsoo

    2016-07-01

    Flexible MgO barrier magnetic tunnel junction (MTJ) devices are fabricated using a transfer printing process. The flexible MTJ devices yield significantly enhanced tunneling magnetoresistance of ≈300% and improved abruptness of switching, as residual strain in the MTJ structure is released during the transfer process. This approach could be useful for flexible electronic systems that require high-performance memory components. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Enhanced magnetization at the Cr/MgO(001) interface

    Energy Technology Data Exchange (ETDEWEB)

    Leroy, M.-A. [Laboratoire Léon Brillouin, IRAMIS, CEA Saclay, 91191 Gif sur Yvette (France); Institut Jean Lamour, Université de Lorraine, 54500 Vandoeuvre les Nancy (France); Bataille, A. M., E-mail: alexandre.bataille@cea.fr; Ott, F. [Laboratoire Léon Brillouin, IRAMIS, CEA Saclay, 91191 Gif sur Yvette (France); Wang, Q.; Fitzsimmons, M. R. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Bertran, F.; Le Fèvre, P.; Taleb-Ibrahimi, A.; Vlad, A.; Coati, A. [Synchrotron SOLEIL, L' Orme des merisiers, 91192 Gif sur Yvette (France); Garreau, Y. [Synchrotron SOLEIL, L' Orme des merisiers, 91192 Gif sur Yvette (France); Matériaux et phénomènes quantiques (MPQ), Université Paris Diderot - Paris 7, Sorbonne-Paris-Cité, CNRS, UMR 7162, 10, rue A. Domon et L. Duquet 75205 Paris Cedex 13 (France); Hauet, T.; Andrieu, S. [Institut Jean Lamour, Université de Lorraine, 54500 Vandoeuvre les Nancy (France); Gatel, C. [CEMES-CNRS, 29 rue Jeanne Marvig, 31055 Toulouse Cedex (France)

    2015-12-21

    We report on the magnetization at the Cr/MgO interface, which we studied through two complementary techniques: angle-resolved photoemission spectroscopy and polarized neutron reflectivity. We experimentally observe an enhanced interface magnetization at the interface, yet with values much smaller than the ones reported so far by theoretical and experimental studies on Cr(001) surfaces. Our findings cast some doubts on the interpretations on previous works and could be useful in antiferromagnetic spin torque studies.

  14. Magnetic domains in martensite of Ni-Mg-Ga alloy

    International Nuclear Information System (INIS)

    Kokorin, V.V.; Babij, O.M.; Dubinko, S.V.; Prokopov, A.R.

    2006-01-01

    The structural changes attendant on intermartensitic transformation in a Ni-Mg-Ga shape memory alloy are considered using magneto-optical visualization with the help of ferrite-garnet monocrystalline films. It is established that on the intermartensitic transformation the complete reorganization of martensite macrostructure fails. Martensite crystals resulted from the basic transformation change somewhat their sizes on intermartensitic transition. The existence of large-scale labyrinth magnetic domain structure is revealed [ru

  15. Study of sintering on Mg-Zn-Ca alloy system

    Science.gov (United States)

    Annur, Dhyah; Lestari, Franciska P.; Erryani, Aprilia; Kartika, Ika

    2018-05-01

    Magnesium and its alloy have gained a lot of interest to be used in biomedical application due to its biodegradable and biocompatible properties. In this study, sintering process in powder metallurgy was chosen to fabricatenonporous Mg-6Zn-1Ca (in wt%) alloy and porous Mg-6Zn-1Ca-10 Carbamide alloy. For creating porous alloy, carbamide (CO(NH2)2 was added to alloy system as the space holder to create porous structure material. Effect of the space holder addition and sintering temperature on porosity, phase formation, mechanical properties, and corrosion properties was observed. Sintering process was done in a tube furnace under Argon atmosphere in for 5 hours. The heat treatment was done in two steps; heated up at 250 °C for 4 hours to decompose spacer particle, followed by heated up at 580 °C or 630 °C for 5 hours. The porous structure of the resulted alloys was examined using Scanning Electron Microscope (SEM), while the phase formation was characterized by X-ray diffraction (XRD) analysis. Mechanical properties were examined using compression testing. From this study, increasing sintering temperature up to 630 °C reduced the mechanical properties of Mg-Zn-Ca alloy.

  16. Structural and mechanical properties of ZnMgO nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Tosun, M. [Istanbul Technical University, Faculty of Mechanical Engineering, 34437, Gumussuyu, Istanbul (Turkey); Ataoglu, S. [Istanbul Technical University, Faculty of Civil Engineering, 34469, Maslak, Istanbul (Turkey); Istanbul Technical University, Earthquake Engineering and Disaster Management Institute, 34469, Maslak, Istanbul (Turkey); Arda, L., E-mail: lutfi.arda@bahcesehir.edu.tr [Bahcesehir University, Faculty of Arts and Sciences, Department of Mathematics and Computer Sciences, Ciragan Cad, Osmanpasa Mektebi Sok, 34349, Besiktas, Istanbul (Turkey); Ozturk, O.; Asikuzun, E. [Kastamonu University, Faculty of Arts and Sciences, Department of Physics, 37100, Kastamonu (Turkey); Akcan, D. [Bahcesehir University, Faculty of Arts and Sciences, Department of Mathematics and Computer Sciences, Ciragan Cad, Osmanpasa Mektebi Sok, 34349, Besiktas, Istanbul (Turkey); Cakiroglu, O. [Hasan Ali Yucel Education Faculty, Istanbul University, 34452, Beyazit, Istanbul (Turkey)

    2014-01-10

    This study reports the effect of annealing temperature on the structure and mechanical properties of Zn{sub 0.95}Mg{sub 0.05}O bulk samples by using digital Vickers microhardness tester, X-ray diffraction analysis, scanning electron microscopy and electron dispersive X-ray measurements. The samples were prepared using Zn and Mg based alkoxed by the sol–gel technique and annealed at various temperatures (500, 600, 700 and 800 °C). Vickers microhardness, elastic modulus, yield strength and fracture toughness values of Zn{sub 0.95}Mg{sub 0.05}O bulk samples were separately calculated and compared with each other. The experimental results of hardness measurements were analyzed using Meyer's law, Proportional Specimen Resistance (PSR) and Elastic/Plastic Deformation (EPD) models and Hays–Kendall (HK) approach. Finally, it was seen that HK approach is the most successful model for the microhardness analysis of these materials.

  17. Resonant proton scattering of $^{22}$Mg and $^{21}$Na

    CERN Multimedia

    Di julio, D D; Jansson, K; Rudolph, D; Fynbo, H O U; Nilsson, T; Perea martinez, A

    In our letter-of-intent, INTC-I-051, we discussed the physics case for scattering and transfer reactions involving light nuclei in the break-out region of the rp-process. The Committee found the physics case compelling and supported the letter-of-intent under the premise that beams of proper quality were developed and that an adequate detector set-up was presented. As these two requirements have been met recently we now propose to study resonant proton scattering of $^{22}$Mg to identify the states at 1.733 MeV and 2.575 MeV in $^{23}$Al that have been reported from the $^{24}$Mg($^{7}$Li,$^{8}$He)$\\,^{23}\\!$Al reaction but that remained unobserved in the only resonant proton scattering experiment performed with $^{22}$Mg so far. In particular we should be able to investigate the character of the proton emission of the 2.575 MeV state which may also have a significant inelastic branch. We also propose to perform resonant proton scattering on $^{21}$Na above $\\alpha$-particle threshold with $^{18}$Ne to study ...

  18. Adsorption of Na, Mg, and Al atoms on BN nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Beheshtian, Javad [Department of Chemistry, Shahid Rajaee Teacher Training University, P.O. Box: 16875-163, Tehran (Iran, Islamic Republic of); Peyghan, Ali Ahmadi, E-mail: ahmadi.iau@gmail.com [Young Researchers Club, Islamic Azad University, Islamshahr Branch, Tehran (Iran, Islamic Republic of); Bagheri, Zargham [Physics group, Science department, Islamic Azad University, Islamshahr Branch, P.O. Box: 33135-369, Islamshahr, Tehran (Iran, Islamic Republic of)

    2012-12-30

    Adsorption of three metals (Na, Mg, and Al) on the surface of BN nanotubes (BNNT) has been investigated by using density functional theory. Adsorption energies for Na and Al atoms have been calculated to be about - 0.22 to - 0.61 eV, respectively. Upon the metal adsorption, energy gap between highest occupied and lowest unoccupied orbitals of the tube is dramatically decreased, resulting in enhanced electrical conductivity. However, in the case of Mg atom, the low adsorption energy cannot change electronic property of the tube. The semi-conductive BNNT transform to n-type semiconductor after adsorption of Na atom. The metal adsorption modifies work function of the BNNT and consequently the field-emission current densities of metal-BNNT may be significantly enhanced. - Highlights: Black-Right-Pointing-Pointer Adsorption of Na, Mg, and Al atoms on the BN nanotubes (BNNT) was studied. Black-Right-Pointing-Pointer Adsorption energies for Na and Al atoms are about - 0.22 to - 0.61 eV, respectively. Black-Right-Pointing-Pointer Energy gap of the tube dramatically decreases upon the metals adsorption. Black-Right-Pointing-Pointer Semiconductor BNNT transform to n-type ones upon adsorption of Na and Al atoms. Black-Right-Pointing-Pointer The field-emission current densities of metal-BNNT may be significantly enhanced.

  19. Neural network potential for Al-Mg-Si alloys

    Science.gov (United States)

    Kobayashi, Ryo; Giofré, Daniele; Junge, Till; Ceriotti, Michele; Curtin, William A.

    2017-10-01

    The 6000 series Al alloys, which include a few percent of Mg and Si, are important in automotive and aviation industries because of their low weight, as compared to steels, and the fact their strength can be greatly improved through engineered precipitation. To enable atomistic-level simulations of both the processing and performance of this important alloy system, a neural network (NN) potential for the ternary Al-Mg-Si has been created. Training of the NN uses an extensive database of properties computed using first-principles density functional theory, including complex precipitate phases in this alloy. The NN potential accurately reproduces most of the pure Al properties relevant to the mechanical behavior as well as heat of solution, solute-solute, and solute-vacancy interaction energies, and formation energies of small solute clusters and precipitates that are required for modeling the early stage of precipitation and mechanical strengthening. This success not only enables future detailed studies of Al-Mg-Si but also highlights the ability of NN methods to generate useful potentials in complex alloy systems.

  20. Reaction rate of 24Mg(p,γ)25Al

    International Nuclear Information System (INIS)

    Powell, D.C.; Iliadis, C.; Champagne, A.E.; Grossmann, C.A.; Hale, S.E.; Hansper, V.Y.; McLean, L.K.

    1999-01-01

    The proton-capture reaction on 24 Mg has been investigated in the bombarding energy range of E p =0.2-1.7 MeV. Resonance properties (strengths, branching ratios and lifetimes) of low-energy resonances have been measured. From the experimental results, accurate proton partial widths, γ-ray partial widths and total widths (Γ p , Γ γ , and Γ) have been deduced. The present experimental information establishes the 24 Mg+p reaction rates over the temperature range T=0.02-2.0 GK with statistical uncertainties of 5% to 21%. Our recommended reaction rates deviate from previous estimates by 18% to 45%. Based on our results, we can rule out the recent suggestion that the total width of the E R =223 keV resonance has a significant influence on the reaction rates. We also discuss several effects that might give rise to systematic uncertainties in the reaction rates. The astrophysical implications for hydrogen burning of 24 Mg at low stellar temperatures are presented

  1. Characterization of the microstructure in Mg based alloy

    KAUST Repository

    Kutbee, Arwa T

    2013-06-01

    The cast products Mg–Sn based alloys are promising candidates for automobile industries, since they provide a cheap yet thermally stable alternative to existing alloys. One drawback of the Mg–Sn based alloys is their insufficient hardness. The hardenability can be improved by engineering the microstructure through additions of Zn to the base alloy and selective aging conditions. Therefore, detailed knowledge about the microstructural characteristics and the role of Zn to promote precipitation hardening is essential for age hardenable Mg-based alloys. In this work, microstructural investigation of the Mg–1.4Sn–1.3Zn–0.1Mn (at.%) precipitation system was performed using TEM. The chemical composition of the precipitates was analyzed using EDS. APT was employed to obtain precise chemical information on the distribution of Zn in the microstructure. It was found from microstructural studies that different precipitates with varying sizes and phases were present; lath-shaped precipitates of the Mg2Sn phase have an incoherent interface with the matrix, unlike the lath-shaped MgZn2 precipitates. Furthermore, nano-sized precipitates dispersed in the microstructure with short-lath morphology can either be enriched with Sn or Zn. On the other hand, APT analysis revealed the strong repulsion between Sn and Zn atoms in a portion of the analysis volume. However, larger reconstruction volume required to identify the role of Zn is still limited to the optimization of specimen preparation.

  2. Phosphorus Doped Zn 1- x Mg x O Nanowire Arrays

    KAUST Repository

    Lin, S. S.

    2009-11-11

    We demonstrate the growth of phosphorus doped Zn 1-xMg xO nanowire (NW) using pulsed laser deposition. For the first time, p-type Zn 0.92Mg 0.08O:P NWs are likely obtained In reference to atomic force microscopy based piezoelectric output measurements, X-ray photoelectron spectroscopy, and the transport property between the NWs and a n-type ZnO film. A shallow acceptor level of ∼140 meV Is identified by temperaturedependent photoluminescence. A piezoelectric output of 60 mV on average has been received using the doped NWs. Besides a control on NW aspect ratio and density, band gap engineering has also been achieved by alloying with Mg to a content of x = 0.23. The alloyed NWs with controllable conductivity type have potential application In high-efficiency all-ZnO NWs based LED, high-output ZnO nanogenerator, and other optical or electrical devices. © 2009 American Chemical Society.

  3. The electric dipole moment of magnesium deuteride, MgD

    Energy Technology Data Exchange (ETDEWEB)

    Steimle, Timothy C., E-mail: TSteimle@asu.edu; Zhang, Ruohan [Department of Chemistry and Biochemistry, Arizona State University, Tempe, Arizona 85287-1604 (United States); Wang, Hailing [State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai, 200062 (China)

    2014-06-14

    The (0,0) A{sup 2}Π–X {sup 2}Σ{sup +} band of a cold molecular beam sample of magnesium monodeuteride, MgD, has been recorded field-free and in the presence of a static electric field of up to 11 kV/cm. The lines associated with the lowest rotational levels are detected for the first time. The field-free spectrum was analyzed to produce an improved set of fine structure parameters for the A{sup 2}Π (v = 0) state. The observed electric field induced splittings and shifts were analyzed to produce permanent electric dipole moments, μ{sup -vector}{sub el} of 2.567(10)D and 1.31(8)D for A{sup 2}Π (v = 0) and X{sup 2}Σ{sup +}(v = 0) states, respectively. The recommended value for μ{sup -vector}{sub el}(X{sup 2}Σ{sup +} (v = 0)) for MgH, based upon the measured value for MgD, is 1.32(8)D.

  4. MgB sub 2 superconductor: a review

    CERN Document Server

    Mollah, S; Chaudhuri, B K

    2003-01-01

    Synthesis, structure and properties of the most intensively studied newly discovered intermetallic binary superconductor MgB sub 2 have been reviewed up to October, 2002. It has a hexagonal unit cell with cell parameters a approx 3.1432 A and c approx 3.5193 A. MgB sub 2 bulk samples synthesized under high pressure (approx 3.5 GPa) and high temperature (approx 1000 degC) has density approx 2.63 g/cm sup 3. The normal state carriers of MgB sub 2 are holes which have been established from the positive thermoelectric power and Hall coefficient measurements. The external pressure decreases the critical temperature (T sub c) with dT sub c /dP in the range of -1 to -2 K/GPa. The T sub c decreases rapidly by the doping of Mn, Li, Co, C, Al, Ni and Fe but increases slightly by Zn doping. However, no significant change of T sub c is observed by the doping of Si and Be. It is further noticed that the anisotropic ratio gamma(= H sub c sub 2 sup a sup b /H sub c sub 2 sup c) approx 1-5 with lower critical field (H sub c ...

  5. Analyzing in rotating asynchronous machine MG set synchronising fault

    International Nuclear Information System (INIS)

    Lu Mingyang; Li Bo; Liu Yu; Fang Yinping

    2014-01-01

    In the commissioning work for MG set at FQNPC Unit l, MG-set l and MG-set 2 can not be synchronized lead to all two generator circuit breakers tripped. The description of the wave in the commissioning and the principle in phase compound excitation are all mentioned in this paper. After wave analysis and theory comparison, the direct cause of this problem is the reactive current in the two parallel synchronous generators, the real reason is parallel excitation contactor operation failed. Which could occur by these single failures, as follows, The synchronizing relay broken. The parallel excitation contactor occur the functional failure. The synchronizing signal trigger, and the order of execution about the breaker of generator and the parallel excitation contactor error. In order to solve these problem, regulating the voltage of generator is necessary. Redundant excitation contactor and relay is also need. After the maintenance, before the generator synchronized must test and verify the parallel excitation contactor works well. (authors)

  6. Environmental Management Performance Report to DOE-RL December 2000

    Energy Technology Data Exchange (ETDEWEB)

    EDER, D.M.

    2000-12-01

    This section provides an executive level summary of the performance information covered in this report and is intended to bring to Management's attention that information considered to be most noteworthy. All cost, schedule, milestone commitments, performance measures, and safety data is current as of October 31. Accomplishments, Issues and Integration items are current as of November 17 unless otherwise noted. The section begins with a description of notable accomplishments that have occurred since the last report and are considered to have made the greatest contribution toward safe, timely, and cost-effective clean up. Following the accomplishment section is an overall fiscal year-to-date summary analysis addressing cost, schedule, and milestone performance. Overviews of safety ensue. The next segment of the Executive Summary, entitled Critical Issues, is designed to identify the high-level challenges to achieving cleanup progress. The next section includes FY 2001 EM Management Commitment High Visibility Project Milestones and Critical Few Performance Measures. The Key Integration Activities section follows next, highlighting PHMC activities that cross contractor boundaries and demonstrate the shared value of partnering with other Site entities to accomplish the work. Concluding the Executive Summary, a forward-looking synopsis of Upcoming Planned Key Events is provided.

  7. Technology information profile: RL321103 -- In situ gamma spectrometer

    International Nuclear Information System (INIS)

    Schilk, A.J.

    1993-11-01

    Past operations of uranium production and support facilities at several Department of Energy (DOE) sites have occasionally resulted in the local contamination of some surface and subsurface soils. Such contamination commonly occurs within waste burial sites, cribs, pond bottom sediments, and areas surrounding waste tanks or uranium scrap, ore, tailing, and slag heaps. The thorough cleanup of these sites is a major public concern and a high priority for the DOE, but before any effective remedial protocols can be established, the three-dimensional distributions of the uranium contaminants must be adequately characterized. Unfortunately, traditional means of obtaining soil activities (e.g., grab sampling followed by laboratory analyses) are notoriously cumbersome, expensive, time-consuming, and often non-representative when very large areas are being surveyed. Hence, new technologies must be developed, or existing ones improved, to allow for the cheaper, better, faster (i.e., real-time) and safer characterization of uranium concentrations at these critical sites. The primary objective for this program is to develop, construct, and field/pilot test the in situ gamma spectrometer for the rapid measurement of uranium in surface and shallow subsurface soils at the Fernald site in Ohio

  8. loaded Eudragit RL 100 Microspheres Prepared by an Emulsion

    African Journals Online (AJOL)

    Erah

    drug release profiles of the microspheres at pH 1.2 showed poor drug release characteristics while at. pH 6.8 ... drug delivery, improve bioavailability and stability and target drug to ... The factors affecting particle size, drug loading and drug.

  9. Solved problems concerning RL and DC circuits in college textbooks

    Directory of Open Access Journals (Sweden)

    Norah Silvana Giacosa

    2015-10-01

    Full Text Available In this paper, we describe and characterize the solved problems concerning LR circuits in direct current that are present in twelve college textbooks commonly used in Argentine Republic. These books were examined through content analysis. The results indicate that in the analyzed sample, in general terms, the explicitness is deficient for the physic systems studied, the proposed hypotheses, their limits of validity and for the verbalized explanations. On the other hand, the displayed resolution of the problems has little coherence with the research work conducted, and this would not promote the scientific work in students. Based on these outcomes and implications for teaching, we noticed that reinforcing the conceptual issues in the classroom that are not enough emphasized in the textbooks is an avoidable task for Physics professors of the basic college cycle.

  10. Parton recombination model including resonance production. RL-78-040

    International Nuclear Information System (INIS)

    Roberts, R.G.; Hwa, R.C.; Matsuda, S.

    1978-05-01

    Possible effects of resonance production on the meson inclusive distribution in the fragmentation region are investigated in the framework of the parton recombination model. From a detailed study of the data on vector-meson production, a reliable ratio of the vector-to-pseudoscalar rates is determined. Then the influence of the decay of the vector mesons on the pseudoscalar spectrum is examined, and the effect found to be no more than 25% for x > 0.5. The normalization of the non-strange antiquark distributions are still higher than those in a quiescent proton. The agreement between the calculated results and data remain very good. 36 references

  11. TELLUS_OCEAN_GIF_CSR_RL05:1

    Data.gov (United States)

    National Aeronautics and Space Administration — The images were generated from the monthly ocean mass grids, which contain ocean water mass given as equivalent water thickness derived from the Center of Space...

  12. TELLUS_OCEANEOF_GIF_CSR_RL05:1

    Data.gov (United States)

    National Aeronautics and Space Administration — The images were generated from the monthly ocean mass grids, which contain ocean water mass given as equivalent water thickness derived from the Center of Space...

  13. Modeling the Substrate Skin Effects in Mutual RL Characteristics.,

    Directory of Open Access Journals (Sweden)

    D. de Roest

    2003-12-01

    Full Text Available The goal of this work was to model the influence of the substrateskin effects on the distributed mutual impedance per unit lengthparameters of multiple coupled on-chip interconnects. The proposedanalytic model is based on the frequency-dependent distribution of thecurrent in the silicon substrate and the closed form integrationapproach. It is shown that the calculated frequency-dependentdistributed mutual inductance and the associated mutual resistance arein good agreement with the results obtained from CAD-oriented circuitmodeling technique.

  14. Bukowskisel tuleb 533. oksjon / Õnne Pärl

    Index Scriptorium Estoniae

    Pärl, Õnne, 1965-

    2004-01-01

    Skandinaavia suurimast Bukowskise oksjonifirmast. Eesti kunsti müügist Bukowskise-Hörhammeri oksjonitel. Oksjonitel on olnud väliseestlaste Herman Talviku, Joann-Voldemar Saarniidu, Hugo Lepiku ja Veronika Keerdoja teoseid

  15. Filmipärl "Suur õgimine" / Kristiina Davidjants

    Index Scriptorium Estoniae

    Davidjants, Kristiina, 1974-

    2007-01-01

    Marco Ferreri mängufilm "Suur õgimine" ("La grande bouffe") : osades Marcello Mastroianni, Michel Piccoli, Philippe Noiret, Ugo Tognazzi : operaator Mario Vulpiani : helilooja Philippe Sarde : Prantsusmaa - Itaalia 1973

  16. Biotreatment of anthraquinone dye Drimarene Blue K2RL

    African Journals Online (AJOL)

    ISHIOMA

    ... 2010 Academic Journals. Full Length Research Paper ... The dye is toxic, carcinogenic ... Microbial decolorization and degradation is an environment friendly ... Chemicals. The majority of chemical compounds and media components were.

  17. Parton recombination model including resonance production. RL-78-040

    Energy Technology Data Exchange (ETDEWEB)

    Roberts, R. G.; Hwa, R. C.; Matsuda, S.

    1978-05-01

    Possible effects of resonance production on the meson inclusive distribution in the fragmentation region are investigated in the framework of the parton recombination model. From a detailed study of the data on vector-meson production, a reliable ratio of the vector-to-pseudoscalar rates is determined. Then the influence of the decay of the vector mesons on the pseudoscalar spectrum is examined, and the effect found to be no more than 25% for x > 0.5. The normalization of the non-strange antiquark distributions are still higher than those in a quiescent proton. The agreement between the calculated results and data remain very good. 36 references.

  18. First-principle Calculations of Mechanical Properties of Al2Cu, Al2CuMg and MgZn2 Intermetallics in High Strength Aluminum Alloys

    Directory of Open Access Journals (Sweden)

    LIAO Fei

    2016-12-01

    Full Text Available Structural stabilities, mechanical properties and electronic structures of Al2Cu, Al2CuMg and MgZn2 intermetallics in Al-Zn-Mg-Cu aluminum alloys were determined from the first-principle calculations by VASP based on the density functional theory. The results show that the cohesive energy (Ecoh decreases in the order MgZn2 > Al2CuMg > Al2Cu, whereas the formation enthalpy (ΔH decreases in the order MgZn2 > Al2Cu > Al2CuMg. Al2Cu can act as a strengthening phase for its ductile and high Young's modulus. The Al2CuMg phase exhibits elastic anisotropy and may act as a crack initiation point. MgZn2 has good plasticity and low melting point, which is the main strengthening phase in the Al-Zn-Mg-Cu aluminum alloys. Metallic bonding mode coexists with a fractional ionic interaction in Al2Cu, Al2CuMg and MgZn2, and that improves the structural stability. In order to improve the alloys' performance further, the generation of MgZn2 phase should be promoted by increasing Zn content while Mg and Cu contents are decreased properly.

  19. Influence of particle size of Mg powder on the microstructure and critical currents of in situ powder-in-tube processed MgB_2 wires

    International Nuclear Information System (INIS)

    Kumakura, Hiroaki; Ye, Shujun; Matsumoto, Akiyoshi; Nitta, Ryuji

    2016-01-01

    We fabricated in situ powder-in-tube(PIT) MgB_2 wires using three kinds of Mg powders with particle size of ∼45 μm, ∼150 μm and 212∼600 μm. Mg particles were elongated to filamentary structure in the wires during cold drawing process. Especially, long Mg filamentary structure was obtained for large Mg particle size of 212∼600 μm. Critical current density, J_c, increased with increasing Mg particle size for 1 mm diameter wires. This is due to the development of filamentary structure of high density MgB_2 superconducting layer along the wires. This MgB_2 structure is similar to that of the internal Mg diffusion (IMD) processed MgB_2 wires. However, J_c of the wires fabricated with 212∼600 μm Mg particle size decreased and the scattering of J_c increased with decreasing wire diameter, while the J_c of the wires with ∼45 μm Mg particle was almost independent of the wire diameter. The cross sectional area reduction of the Mg particles during the wire drawing is smaller than that of the wire. When using large size Mg particle, the number of Mg filaments in the wire cross section is small. These two facts statistically lead to the larger scattering of Mg areal fraction in the wire cross section with proceeding of wire drawing process, resulting in smaller volume fraction of MgB_2 in the wire and lower J_c with larger scattering along the wire. SiC nano powder addition is effective in increasing J_c for all Mg particle sizes. (author)

  20. Raman-spectroscopic (Fe/Fe+Mg, CO2) and Structural studies of Mg-Fe cordierites

    International Nuclear Information System (INIS)

    Haefeker, U.

    2013-01-01

    In the course of this dissertation synthetic hexagonal and orthorhombic Mg-Fe-cordierites have been investigated with Raman-spectroscopy and XRD methods. Cordierite´s Mg- and Fe-end-members as well as their Mg-Fe solid solutions with the chemical formula (Mg, Fe 2+ ) 2 Al 4 Si 5 O 18 *nH 2 O have been synthesized. Raman-data of synthetic hydrous Mg- and Fe-cordierites have been obtained in the wavenumber-region 100-1250 cm-1 and the experimental data were then compared with the results of quantum-mechanical calculations. 86 theoretical bands could be related to specific vibrational modes of the tetrahedral and octahedral sites of the cordierite structure. Maximum and mean deviation between experimentally-derived bands and calculated modes were ±7 cm -1 for Mg-cordierite and ±19 cm -1 for Fe-cordierite. Spectra comparison revealed a trend of peak downshifting as a consequence of Fe-incorporation. The calculations now allow more accurate interpretation of the Raman spectra with respect to structural changes of cordierite, resulting from Al-Si ordering and Mg-Fe exchange. Atomic motions in cordierite have been compared with those of the structurally similar mineral beryl. Investigations of 16 H 2 O-bearing synthetic well-ordered Mg-Fe-cordierites (XFe =0-1) with micro-Raman spectroscopy revealed a linear correlation between the Fe/Mg ratio and the position of certain Raman peaks. The peaks (wave-number Mg-/Fe-cordierite) at 122/111, 262/257, 430/418, 579/571, 974/967, and 1012/1007 cm -1 were selected for a detailed deconvolution analysis . The shifts of these peaks were then plotted vs. XFe and regression of the data lead to the formulation of a set of linear equations. In addition, the effect of different H 2 O contents and the degree of Al-Si ordering on the Fe/Mg determination were also investigated. Testing the calibration against data from six well-characterized natural cordierite samples yielded excellent agreement. Existing calibration diagrams for CO 2

  1. Corrosion Resistance of the Superhydrophobic Mg(OH2/Mg-Al Layered Double Hydroxide Coatings on Magnesium Alloys

    Directory of Open Access Journals (Sweden)

    Fen Zhang

    2016-04-01

    Full Text Available Coatings of the Mg(OH2/Mg-Al layered double hydroxide (LDH composite were formed by a combined co-precipitation method and hydrothermal process on the AZ31 alloy substrate in alkaline condition. Subsequently, a superhydrophobic surface was successfully constructed to modify the composite coatings on the AZ31 alloy substrate using stearic acid. The characteristics of the composite coatings were investigated by means of X-ray diffractometer (XRD, Fourier transform infrared spectroscopy (FTIR, X-ray photoelectron spectroscopy (XPS, scanning electronic microscope (SEM and contact angle (CA. The corrosion resistance of the coatings was assessed by potentiodynamic polarization, the electrochemical impedance spectrum (EIS, the test of hydrogen evolution and the immersion test. The results showed that the superhydrophobic coatings considerably improved the corrosion resistant performance of the LDH coatings on the AZ31 alloy substrate.

  2. Magnetic anisotropy of thin sputtered MgB2 films on MgO substrates in high magnetic fields

    Directory of Open Access Journals (Sweden)

    Savio Fabretti

    2014-03-01

    Full Text Available We investigated the magnetic anisotropy ratio of thin sputtered polycrystalline MgB2 films on MgO substrates. Using high magnetic field measurements, we estimated an anisotropy ratio of 1.35 for T = 0 K with an upper critical field of 31.74 T in the parallel case and 23.5 T in the perpendicular case. Direct measurements of a magnetic-field sweep at 4.2 K show a linear behavior, confirmed by a linear fit for magnetic fields perpendicular to the film plane. Furthermore, we observed a change of up to 12% of the anisotropy ratio in dependence of the film thickness.

  3. Obtention of Al-Mg alloys of porous morphology; Obtencion de aleaciones Al-Mg de morfologia porosa

    Energy Technology Data Exchange (ETDEWEB)

    Barragan V, J.; Zamora R, L.; Sandoval J, A.R.; Iturbe G, J.L. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

    2006-07-01

    With the objective of using it as fuel cell, a Mg{sub 25}AI alloy of porous morphology was obtained. The material it was hydrogenates at 200 C by different time. It was analyzed by Scanning Electron Microscopy SEM and X-ray diffion, XRD. Those XRD diffractographs present peaks run toward the origin, that which indicates a volume increase of the unitary cell by effect of the hydrogen absorption. (Author)

  4. Effects of carbon concentration and filament number on advanced internal Mg infiltration-processed MgB2 strands

    International Nuclear Information System (INIS)

    Li, G Z; Sumption, M D; Zwayer, J B; Susner, M A; Collings, E W; Rindfleisch, M A; Thong, C J; Tomsic, M J

    2013-01-01

    In this paper we show that an advanced internal Mg infiltration method (AIMI) is effective in producing superconducting wires containing dense MgB 2 layers with high critical current densities. The in-field critical current densities of a series of AIMI-fabricated MgB 2 strands were investigated in terms of C doping levels, heat treatment (HT) time and filament numbers. The highest layer J c for our monofilamentary AIMI strands was 1.5 × 10 5 A cm −2 at 10 T, 4.2 K, when the C concentration was 3 mol% and the strand was heat-treated at 675 ° C for 4 h. Transport critical currents were also measured at 4.2 K on short samples and 1 m segments of 18-filament C doped AIMI strands. The layer J c s reached 4.3 × 10 5 A cm −2 at 5 T and 7.1 × 10 4 A cm −2 at 10 T, twice as high as those of the best powder-in-tube strands. The analysis of these results indicates that the AIMI strands, possessing both high layer J c s and engineering J e s after further optimization, have strong potential for commercial applications. (paper)

  5. Properties of thymidylate synthetase from Ehrlich ascites carcinoma cells. Effect of Mg2/ and MgATP2-.

    Science.gov (United States)

    Jastreboff, M; Kedzierska, B; Rode, W

    1982-01-15

    Ehrlich ascites carcinoma thymidylate synthetase was purified to electrophoretic homogeneity by affinity chromatography on 10-formyl-5,8-dideazofolate-ethyl-Sepharose. Electrophoretic analysis of the formation of the enzyme-5-fluorodeoxyuridylate-5,10-methylenetetrahydrofolate complexes showed the presence of two binding sites for 5-fluorodeoxyuridylate on the enzyme molecule. Molecular weight of the native enzyme was found to be 78,5000, whereas that of its monomer was 38, 500. The apparent Michaelis constants for dUMP and (+/-)-L-5,10-methylenetetrahydrofolate were 1.3 +/- 0.4 and 32.2 +/- 0.7 micrometers respectively. Phosphate acted as a weak inhibitor, competitive toward dUMP. The enzyme reaction exhibited a temperature-dependent change of activation energy, reflected in the binding affinity of dUMP, with a transitional temperature of 35.8 degrees. Both Mg2+ and MgATP2- were strong activators of the enzyme, MgATP2- being more effective.

  6. Electron microscopy of Mg/TiO{sub 2} photocatalyst morphology for deep desulfurization of diesel

    Energy Technology Data Exchange (ETDEWEB)

    Yin, Yee Cia, E-mail: gabrielle.ciayin@gmail.com [Department of Chemical Engineering, Universiti Teknologi PETRONAS, 31750 Tronoh, Perak (Malaysia); Kait, Chong Fai, E-mail: chongfaikait@petronas.com.my; Fatimah, Hayyiratul, E-mail: hayyiratulfatimah@yahoo.com; Wilfred, Cecilia, E-mail: cecili@petronas.com.my [Department of Fundamental and Applied Sciences, Universiti Teknologi PETRONAS, 31750 Tronoh, Perak (Malaysia)

    2015-07-22

    A series of Mg/TiO{sub 2} photocatalysts were prepared and characterized using Field Emission Scanning Electron Microscopy (FESEM) and High-Resolution Transmission Electron Microscopy (HRTEM). The average particle sizes of the photocatalysts were ranging from 25.7 to 35.8 nm. Incorporation of Mg on TiO{sub 2} did not lead to any surface lattice distortion to TiO{sub 2}. HRTEM data indicated the presence of MgO and Mg(OH){sub 2} mixture at low Mg loading while at higher Mg loading, the presence of lamellar Mg-oxyhydroxide intermediates and Mg(OH){sub 2}.

  7. Electron microscopy of Mg/TiO2 photocatalyst morphology for deep desulfurization of diesel

    International Nuclear Information System (INIS)

    Yin, Yee Cia; Kait, Chong Fai; Fatimah, Hayyiratul; Wilfred, Cecilia

    2015-01-01

    A series of Mg/TiO 2 photocatalysts were prepared and characterized using Field Emission Scanning Electron Microscopy (FESEM) and High-Resolution Transmission Electron Microscopy (HRTEM). The average particle sizes of the photocatalysts were ranging from 25.7 to 35.8 nm. Incorporation of Mg on TiO 2 did not lead to any surface lattice distortion to TiO 2 . HRTEM data indicated the presence of MgO and Mg(OH) 2 mixture at low Mg loading while at higher Mg loading, the presence of lamellar Mg-oxyhydroxide intermediates and Mg(OH) 2

  8. Parenteral magnesium load testing with 28Mg in weanling and young adult rats

    International Nuclear Information System (INIS)

    Caddell, J.L.; Calhoun, N.R.; Howard, M.P.; Patterson, K.Y.; Smith, J.C. Jr.

    1981-01-01

    A sound diagnostic test for Mg deficiency is needed. This is a report of the parenteral Mg load test conducted in weanling and young adult rats fed a purified basal diet containing 3 mg magnesium/100 g with 150 mg of added magnesium/100 g (control) or 0 added magnesium (deficient). Weanlings were studied at about 1 week of dietary treatment and young adults at 2 weeks. The protocol included: a) a 6-hour preload urinary collection; b) an intraperitoneal load of 15 mg of magnesium/kg (weanlings) or 12 mg/kg (young adults) with 2 microCi 28Mg given simultaneously with each load; c) a 6-hour postload urinary collection; d) chemical analysis of selected tissues and urine for Mg; and e) 28Mg counting 6 and 24 hours postload. Controls all excreted large amounts of Mg pre- and postload, retaining less than 26% of nonradioactive loads. They had high urinary 28Mg counts. In Mg-deficient animals, the concentration of Mg in bone more than halved. These animals avidly conserved Mg and retained over 85% of nonradioactive Mg loads. Their 28Mg activity in vital organs was 3--6 times greater than in controls. We concluded that the parenteral Mg load test reliably identifies severe Mg deficiency

  9. The magnesium isotope (δ26Mg) signature of dolomites

    Science.gov (United States)

    Geske, A.; Goldstein, R. H.; Mavromatis, V.; Richter, D. K.; Buhl, D.; Kluge, T.; John, C. M.; Immenhauser, A.

    2015-01-01

    Dolomite precipitation models and kinetics are debated and complicated due to the complex and temporally fluctuating fluid chemistry and different diagenetic environments. Using well-established isotope systems (δ18O, δ13C, 87Sr/86Sr), fluid inclusions and elemental data, as well as a detailed sedimentological and petrographic data set, we established the precipitation environment and subsequent diagenetic pathways of a series of Proterozoic to Pleistocene syn-depositional marine evaporative (sabkha) dolomites, syn-depositional non-marine evaporative (lacustrine and palustrine) dolomites, altered marine ("mixing zone") dolomites and late diagenetic hydrothermal dolomites. These data form the prerequisite for a systematic investigation of dolomite magnesium isotope ratios (δ26Mgdol). Dolomite δ26Mg ratios documented here range, from -2.49‰ to -0.45‰ (δ26Mgmean = -1.75 ± 1.08‰, n = 42). The isotopically most depleted end member is represented by earliest diagenetic marine evaporative sabkha dolomites (-2.11 ± 0.54‰ 2σ, n = 14). In comparing ancient compositions to modern ones, some of the variation is probably due to alteration. Altered marine (-1.41 ± 0.64‰ 2σ, n = 4), and earliest diagenetic lacustrine and palustrine dolomites (-1.25 ± 0.86‰ 2σ, n = 14) are less negative than sabkha dolomites but not distinct in composition. Various hydrothermal dolomites are characterized by a comparatively wide range of δ26Mg ratios, with values of -1.44 ± 1.33‰ (2σ, n = 10). By using fluid inclusion data and clumped isotope thermometry (Δ47) to represent temperature of precipitation for hydrothermal dolomites, there is no correlation between fluid temperature (∼100 to 180 °C) and dolomite Mg isotope signature (R2 = 0.14); nor is there a correlation between δ26Mgdol and δ18Odol. Magnesium-isotope values of different dolomite types are affected by a complex array of different Mg sources and sinks, dissolution/precipitation and non

  10. Genesis of Cenozoic intraplate high Mg# andesites in Northeast China

    Science.gov (United States)

    Liu, J. Q.; Chen, L. H.; Zhong, Y.; Wang, X. J.

    2017-12-01

    High-Mg# andesites (HMAs) are usually generated in the converged plate boundary and have genetic relationships with slab subduction. However, it still remained controversial about the origin of those HMAs erupted in the intra-plate setting. Here we present major, trace element, and Sr-Nd-Pb-Hf isotopic compositions for the Cenozoic intra-plate HMAs from Northeast China to constrain their origin and formation process. Cenozoic Xunke volcanic rocks are located in the northern Lesser Khingan Range, covering an area of about 3, 000 km2. These volcanic rocks are mainly basaltic andesite and basaltic trachyandesite, with only several classified as trachyandesite and andesites. They have high SiO2 contents (54.3-57.4 wt%) and Mg# (49.6-57.8), falling into the scope of high Mg# andesites. The Xunke HMAs are enriched in large ion lithophile elements but depleted in high field strength elements, with positive Ba, K, Sr and negative Zr-Hf, and Ti anomalies. Their trace element absolute concentrations are between those of potassic basalts and Wuchagou HMAs. The Xunke HMAs have relatively enriched Sr-Nd-Hf isotopes (87Sr/86Sr = 0.705398-0.705764, ɛNd=-8.8-3.8, ɛHf=0.5-11.7), and low radiogenic Pb isotopes (206Pb/204Pb = 16.701-17.198), towards to the EM1 end-member, which indicates that they are ultimately derived from ancient, recycled crustal components. Primitive silica-rich melts were generated from higher degrees of partial melting of recycled crustal materials (relative to potassic basalts) and then interacted with the peridotite to produce the Xunke HMAs.

  11. Single-crystalline MgAl2O4 spinel nanotubes using a reactive and removable MgO nanowire template

    International Nuclear Information System (INIS)

    Fan Hongjin; Knez, Mato; Scholz, Roland; Nielsch, Kornelius; Pippel, Eckhard; Hesse, Dietrich; Goesele, Ulrich; Zacharias, Margit

    2006-01-01

    Using MgO nanowires as a reactive template, we fabricated for the first time single-crystal MgAl 2 O 4 spinel nanotubes through an interfacial solid-state reaction of MgO-Al 2 O 3 core-shell nanowires. Single-crystal MgO nanowires are coated with a conformal thin layer of amorphous Al 2 O 3 via atomic layer deposition. Subsequent annealing at 700 deg. C activates the interfacial reaction between MgO and Al 2 O 3 , transforming the alumina shell into a spinel shell. Finally, after etching away the remaining MgO core in ammonia sulfuric solution, MgAl 2 O 4 spinel nanotubes are obtained. As a transition from conventional planar spinel layers via thin-film interface reactions, our result might open a window for the fabrication of a wide variety of MgO-based spinel one-dimensional nanostructures

  12. Thermoluminescence of the Z centre in Mg-doped KCl

    International Nuclear Information System (INIS)

    Kamavisdar, V.S.; Deshmukh, B.T.

    1980-01-01

    Optical absorption and thermoluminescence measurements on KCl:Mg 2+ are reported. Bleaching in F band introduces a new glow peak at 406 K in the glow curves. A similar peak is observed in microcrystalline powders. When this peak is thermally cleaned, the broadening of the absorption observed in prolonged F bleached crystals is removed. On the basis of these observations, the glow peak at 406 K is tentatively attributed to Z 1 centres. The glow peak at 394 K observed in microcrystalline powders is attributed to a combined effect of deformation and Z 1 centres. (author)

  13. MAGIICAT I. THE Mg II ABSORBER-GALAXY CATALOG

    Energy Technology Data Exchange (ETDEWEB)

    Nielsen, Nikole M.; Churchill, Christopher W. [New Mexico State University, Las Cruces, NM 88003 (United States); Kacprzak, Glenn G.; Murphy, Michael T., E-mail: nnielsen@nmsu.edu [Swinburne University of Technology, Victoria 3122 (Australia)

    2013-10-20

    We describe the Mg II Absorber-Galaxy Catalog, MAGIICAT, a compilation of 182 spectroscopically identified intermediate redshift (0.07 ≤ z ≤ 1.1) galaxies with measurements of Mg II λλ2796, 2803 absorption from their circumgalactic medium within projected distances of 200 kpc from background quasars. In this work, we present 'isolated' galaxies, which are defined as having no spectroscopically identified galaxy within a projected distance of 100 kpc and a line of sight velocity separation of 500 km s{sup –1}. We standardized all galaxy properties to the ΛCDM cosmology and galaxy luminosities, absolute magnitudes, and rest-frame colors to the B- and K-band on the AB system. We present galaxy properties and rest-frame Mg II equivalent width, W{sub r} (2796), versus galaxy redshift. The well-known anti-correlation between W{sub r} (2796) and quasar-galaxy impact parameter, D, is significant to the 8σ level. The mean color of MAGIICAT galaxies is consistent with an Sbc galaxy for all redshifts. We also present B- and K-band luminosity functions for different W{sub r} (2796) and redshift subsamples: 'weak absorbing' [W{sub r} (2796) < 0.3 Å], 'strong absorbing' [W{sub r} (2796) ≥ 0.3 Å], low redshift (z < (z)), and high redshift (z ≥ (z)), where (z) = 0.359 is the median galaxy redshift. Rest-frame color B – K correlates with M{sub K} at the 8σ level for the whole sample but is driven by the strong absorbing, high-redshift subsample (6σ). Using M{sub K} as a proxy for stellar mass and examining the luminosity functions, we infer that in lower stellar mass galaxies, Mg II absorption is preferentially detected in blue galaxies and the absorption is more likely to be weak.

  14. Diagenetic alteration in low-Mg calcite from macrofossils

    DEFF Research Database (Denmark)

    Ullmann, Clemens Vinzenz; Korte, Christoph

    2015-01-01

    microscopy) and chemical (trace element abundances, isotopic ratios) screening techniques used to assess the alteration degree of low-Mg calcite macrofossils and summarize the findings on diagenetic trends observed for elemental and isotopic systems in such materials. For a robust evaluation...... of the preservation state of biogenic calcite, it is advisable to combine a set of complementary techniques. Absolute limiting values of element and isotope ratios for discarding diagenetically altered materials cannot be universally applied, but should rather be evaluated on a case to case basis. The evaluation can...

  15. The Melting Curve and Premelting of MgO

    OpenAIRE

    Cohen, R. E.; Weitz, J. S.

    1996-01-01

    The melting curve for MgO was obtained using molecular dynamics and a non-empirical, many-body potential. We also studied premelting effects by computing the dynamical structure factor in the crystal on approach to melting. The melting curve simulations were performed with periodic boundary conditions with cells up to 512 atoms using the ab-initio Variational Induced Breathing (VIB) model. The melting curve was obtained by computing $% \\Delta H_m$ and $\\Delta V_m$ and integrating the Clapeyro...

  16. Magnetic Resonances in the Electroexcitation of the 26Mg Nucleus

    International Nuclear Information System (INIS)

    Goncharova, N.G.; Pronkina, N.D.

    2005-01-01

    On the basis of spectroscopic information about direct pickup reactions, the multipole magnetic resonances M2, M4, and M6 of the 26 Mg nucleus are calculated within the particle-core coupling version of the multiparticle shell model. The excitation-energy distribution of the form factors for the multipole magnetic 1(ℎ/2π)ω resonances is obtained for momentum transfers to a nucleus up to 2 fm -1 . A comparison of the results of the calculations for the M6 form factors with corresponding experimental data confirms that the adopted model approximations are realistic

  17. Properties of hot pressed MgB2/Ti tapes

    International Nuclear Information System (INIS)

    Kovac, P.; Husek, I.; Melisek, T.; Fedor, J.; Cambel, V.; Morawski, A.; Kario, A.

    2009-01-01

    Hot axial and hot isostatic pressing was applied for single-core MgB 2 /Ti tapes. Differences in transport current density, n-exponents and critical current anisotropy are discussed and related to the grain connectivity influenced by pressing. The magnetic Hall probe scanning measurements allowed observing the isolated regions for axially hot pressed sample attributed to the longitudinally oriented cracks introduced by pressing. The highest current densities were measured for the tape subjected to hot isostatic pressing due to improved connectivity.

  18. Unusual structures of MgF5- superhalogen anion

    Science.gov (United States)

    Anusiewicz, Iwona; Skurski, Piotr

    2007-05-01

    The vertical electron detachment energies (VDE) of three MgF5- anions were calculated at the outer valence Green function level with the 6-311 + G(3df) basis sets. This species was found to form unusual geometrical structures each of which corresponds to an anionic state exhibiting superhalogen nature. The global minimum structure was described as a system in which two central magnesium atoms are linked via symmetrical triangle formed by three fluorine atoms. Extremely large electron binding energies of these anions (exceeding 8.5 eV in all cases) were predicted and discussed.

  19. Simulation of Cu-Mg metallic glass: Thermodynamics and structure

    DEFF Research Database (Denmark)

    Bailey, Nicholas; Schiøtz, Jakob; Jacobsen, Karsten Wedel

    2004-01-01

    We have obtained effective medium theory interatomic potential parameters suitable for studying Cu-Mg metallic glasses. We present thermodynamic and structural results from simulations of such glasses over a range of compositions. We have produced low-temperature configurations by cooling from...... the melt at as slow a rate as practical, using constant temperature and pressure molecular dynamics. During the cooling process we have carried out thermodynamic analyses based on the temperature dependence of the enthalpy and its derivative, the specific heat, from which the glass transition temperature...

  20. Positronium deuteride and hydride in MgO crystals

    OpenAIRE

    Monge, M. A.; Pareja, R.; González, R.; Chen, Y.

    1996-01-01

    Low-temperature positron lifetime and Doppler broadening measurements were made in MgO crystals containing D− or H− ions in order to investigate the temperature dependence of the positron trapping by D− and H− ions and elucidate the possible formation of PsD (PsH) states. Positrons are trapped at D− and H− ions once the oxygen vacancies, which are more effective positron traps, are eliminated by annealing the crystals at high temperatures in a reducing atmosphere. From the temperature depende...

  1. Impact of Site Elevation on Mg Smelter Design

    Science.gov (United States)

    Baker, Phillip W.

    Site elevation has many surprising and significant impacts on the engineering design of metallurgical plant of all types. Electrolytic magnesium smelters maybe built at high elevation for a variety of reasons including availability of raw material, energy or electric power. Because of the unit processes they typically involve, Mg smelters can be extensively impacted by site elevation. In this paper, generic examples of the design changes required to adapt a smelter originally designed for sea level to operate at 2700 m are presented. While the examples are drawn from a magnesium plant design case, these changes are generically applicable to all industrial plants utilizing similar unit processes irrespective of product.

  2. Specific heat of MgB_2 after irradiation

    OpenAIRE

    Wang, Yuxing; Bouquet, Frederic; Sheikin, Ilya; Toulemonde, Pierre; Revaz, Bernard; Eisterer, Michael; Weber, Harald W.; Hinderer, Joerg; Junod, Alain

    2002-01-01

    We studied the effect of disorder on the superconducting properties of polycrystalline MgB_2 by specific-heat measurements. In the pristine state, these measurements give a bulk confirmation of the presence of two superconducting gaps with 2 Delta 0 / k_B T_c = 1.3 and 3.9 with nearly equal weights. The scattering introduced by irradiation suppresses T_c and tends to average the two gaps although less than predicted by theory. We also found that by a suitable irradiation process by fast neutr...

  3. Thermal desensitization of gamma irradiated LiF:Mg,Ti

    Energy Technology Data Exchange (ETDEWEB)

    Chernov, V.; Rogalev, B.; Afonin, G. (Institute of Geochemistry, Irkutsk (Russian Federation))

    1993-01-01

    The thermoluminescence sensitivity variation of gamma irradiated LiF:Mg,Ti after annealing at temperatures of 300-500[sup o]C has been studied. This variation is shown to be due to concurrent processes of sensitization and damage. Annealing of irradiated crystals leads to the restoration of the initial sensitivity. The damage decay time is approximately an order of magnitude greater than the decay time of the sensitization. The experimental data are interpreted quantitatively within the scope of included gamma track overlapping. (author).

  4. Surface studies of Li-ion and Mg battery electrodes

    Science.gov (United States)

    Esbenshade, Jennifer

    This dissertation focuses on studies of the surfaces of both Li-ion and Mg-ion battery electrodes. A fundamental understanding of processes occurring at the electrode surface is vital to the development of advanced battery systems. Additionally, modifications to the electrode surfaces are made and further characterized for improved performance. LiMn2O4 Cathodes for Li-ion Batteries: Effect of Mn in electrolyte on anode and Au coating to minimize dissolution: LiMn2O4 (LMO) is known to dissolve Mn ions with cycling. This section focuses on both the effect of the dissolution of Mn2+ into the electrolyte as well as Au coating on the LMO to improve electrochemical performance. Electrochemical quartz crystal microbalance (EQCM) was used to monitor changes in mass on the anode, SEM and AES were used to observe changes in surface morphology and chemical composition, and potentiostatic voltammetry was used to monitor charge and discharge capacity. The effect of Cu2+ addition in place of Mn2+ was also studied, as Cu is known to form an underpotential deposition (UPD) monolayer on Au electrodes. Following this, LMO particles were coated with a Au shell by a simple and scalable electroless deposition for use as Li-ion battery cathodes. The Au shell was intended to limit the capacity fade commonly seen with LMO cathodes by reducing the dissolution of Mn. Characterization by SEM, TEM, EELS, and AFM showed that the Au shell was approximately 3 nm thick. The Au shell prevented much of the Mn from dissolving in the electrolyte with 82% and 88% less dissolved Mn in the electrolyte at room temperature and 65 ºC, respectively, as compared to the uncoated LMO. Electrochemical performance studies with half cells showed that the Au shell maintained a higher discharge capacity over 400 cycles by nearly 30% with 110 mA hr g-1 for the 400th cycle as compared to a commercial LMO at 85 mA hr g-1. Similarly, the capacity fade was reduced in full cells: the coated LMO had 47% greater capacity

  5. The neutron transmission of single crystal MgO filters

    International Nuclear Information System (INIS)

    Carpenter, J.M.; Hilleke, R.O.

    1989-01-01

    We have measured and analyzed the wavelength dependence of the transmission probability of a beam of neutrons passing through a single crystal MgO filter at 77 K. The 12.7 cm filter transmits 70% or more of the incident beam at wavelengths greater than about 1.8 A. At shorter wavelengths the transmission probability drops sharply, with 50% transmission occurring at about 1.2 A, and 1% transmission for the range 0.1-0.4 A. We have determined that cooling the filter to 77 K improves the transmission of >1 A neutrons, while further cooling to 25 K shows little additional improvement, and no improvement for short wavelengths. We have identified the wavelengths of the sharp dips in the transmission found in this region caused by Bragg scattering in MgO. We also show how these peaks may be used to calibrate the wavelength scale of time-of-flight measurements taken on instruments using similar filters. (orig.)

  6. MgB2-based superconductors for fault current limiters

    Science.gov (United States)

    Sokolovsky, V.; Prikhna, T.; Meerovich, V.; Eisterer, M.; Goldacker, W.; Kozyrev, A.; Weber, H. W.; Shapovalov, A.; Sverdun, V.; Moshchil, V.

    2017-02-01

    A promising solution of the fault current problem in power systems is the application of fast-operating nonlinear superconducting fault current limiters (SFCLs) with the capability of rapidly increasing their impedance, and thus limiting high fault currents. We report the results of experiments with models of inductive (transformer type) SFCLs based on the ring-shaped bulk MgB2 prepared under high quasihydrostatic pressure (2 GPa) and by hot pressing technique (30 MPa). It was shown that the SFCLs meet the main requirements to fault current limiters: they possess low impedance in the nominal regime of the protected circuit and can fast increase their impedance limiting both the transient and the steady-state fault currents. The study of quenching currents of MgB2 rings (SFCL activation current) and AC losses in the rings shows that the quenching current density and critical current density determined from AC losses can be 10-20 times less than the critical current determined from the magnetization experiments.

  7. Texture development during tensile deformation in Al-Mg alloys

    Energy Technology Data Exchange (ETDEWEB)

    Ohtani, S.; Inagaki, H. [Shonan Inst. of Tech., Fujisawashi (Japan)

    2002-07-01

    Tensile tests were made on commercial A1050 pure Al, A5182 Al-4.4% Mg alloy and A2017 Al-4% Cu alloy by varying the test temperature and the strain rate. Textures developed at various stages of the tensile deformation were investigated with the orientation distribution function analysis. It was found that, during the tensile test of the 1050 pure Al with the strain rate of 3 x 10{sup -4}S{sup -1} at 20 C, tensile axis readily rotated toward left angle 111 right angle stable end orientation. However, such rotation occurred only at the latest stage of the tensile deformation near the ultimate tensile stress, where stress strain curve was almost flattened and work hardening was almost saturated. It was strongly suggested that, since fine and complex dislocation cell structures were developed in such a work-hardened state, smooth and long range dislocation glide such as assumed in the classical Taylor theory would not be possible. To explain the observed texture development, cooperative movement of the dislocations in the cell walls might be necessary. In fact, addition of Mg and Cu, which suppressed strongly the development of well defined cell structures due to P-L effect or dynamic strain ageing, significantly retarded the rotation of tensile axes toward left angle 111 right angle. Interesting enough, textures developed in all these materials investigated were not affected by the strain rate and the temperature of the tensile test. (orig.)

  8. NH AND Mg INDEX TRENDS IN ELLIPTICAL GALAXIES

    International Nuclear Information System (INIS)

    Serven, Jedidiah; Worthey, Guy; Toloba, Elisa; Sanchez-Blazquez, Patricia

    2011-01-01

    We examine the spectrum in the vicinity of the NH3360 index of Davidge and Clark, which was defined to measure the NH absorption around 3360 A and shows almost no trend with velocity dispersion, unlike other N-sensitive indices, which show a strong trend. Computing the effect of individual elements on the integrated spectrum with synthetic stellar population integrated spectra, we find that, while being well correlated with nitrogen abundance, NH3360 is almost equally well anti-correlated with Mg abundance. This prompts the definition of two new indices, Mg3334, which is mostly sensitive to magnesium, and NH3375, which is mostly sensitive to nitrogen. Rather surprisingly, we find that the new NH3375 index shows a trend versus optical absorption feature indices that is as shallow as the NH3360 index. We hypothesize that the lack of a strong index trend in these near-UV indices is due to the presence of an old metal-poor component of the galactic population. Comparison of observed index trends and those predicted by models shows that a modest fraction of an old, metal-poor stellar population could easily account for the observed flat trend in these near-UV indices while still allowing substantial N abundance increase in the larger galaxies.

  9. Magnesium diboride(MgB2) wires for applications

    International Nuclear Information System (INIS)

    Patel, Dipak; Kim, Jung Ho

    2016-01-01

    Field and temperature dependence of the critical current density, Jc, were measured for both un-doped and carbon doped MgB 2 /Nb/Monel wires manufactured by Hyper Tech Research, Inc. In particular, carbon incorporation into the MgB 2 structure using malic acid additive and a chemical solution method can be advantageous because of the highly uniform mixing between the carbon and boron powders. At 4.2 K and 10 T, Jc was estimated to be 25,000 - 25,300 Acm -2 for the wire sintered at 600 degrees C for 4 hours. The irreversibility field, Birr, of the malic acid doped wire was approximately 21.0 - 21.8 T, as obtained from a linear extrapolation of the J-B characteristic. Interestingly enough, the Jc of the malic acid doped sample exceeds 10 5 Acm -2 at 6 T and 4.2 K, which is comparable to that of commercial Nb-Ti wires

  10. Magnesium diboride(MgB{sub 2}) wires for applications

    Energy Technology Data Exchange (ETDEWEB)

    Patel, Dipak; Kim, Jung Ho [Institute for Superconducting and Electronic Materials, Australian Institute for Innovative Materials, University of Wollongong, North Wollongong (Australia)

    2016-03-15

    Field and temperature dependence of the critical current density, Jc, were measured for both un-doped and carbon doped MgB{sub 2}/Nb/Monel wires manufactured by Hyper Tech Research, Inc. In particular, carbon incorporation into the MgB{sub 2} structure using malic acid additive and a chemical solution method can be advantageous because of the highly uniform mixing between the carbon and boron powders. At 4.2 K and 10 T, Jc was estimated to be 25,000 - 25,300 Acm{sup -2} for the wire sintered at 600 degrees C for 4 hours. The irreversibility field, Birr, of the malic acid doped wire was approximately 21.0 - 21.8 T, as obtained from a linear extrapolation of the J-B characteristic. Interestingly enough, the Jc of the malic acid doped sample exceeds 10{sup 5} Acm{sup -2} at 6 T and 4.2 K, which is comparable to that of commercial Nb-Ti wires.

  11. Simple preparation of LiF:Mg,Ti phosphor

    International Nuclear Information System (INIS)

    Moharil, S.V.; Shahare, D.I.; Upaded, S.V.; Deshmukh, B.T.

    1993-01-01

    LiF-TLD 100 is a low-impedance (Z eff = 8.2) tissue equivalent material which is widely used in thermoluminescence (TL) dosimetry of ionizing radiations and personnel monitoring. Mg and Ti have been found to be the major impurities which impart the Tl characteristics. Recipes for the preparation of this phosphor, have not been found to be satisfactory for routine manufacture; there have always been problems associated with reproducibility and even with batch homogeneity. One of the reasons for this is that most procedures start either from readily available LiF or by melting the synthesized LiF, or both. The background impurities in the starting LiF powder can mask the intentional impurities, particularly Ti which has to be doped in rather small concentrations (10 p.p.m.). Melting LiF can again be tricky, as the LiF melt is volatile and highly corrosive. In this letter we report the preparation of LiF: Mg, Ti. The impurities were incorporated during the synthesis of LiF. The phosphor was prepared by heat treatments in ambient air without melting the compound. The characteristics of the prepared phosphors were studied and compared with those of LiF-TLD 100. (author)

  12. Estudio de estabilidad de tabletas de propiltiouracilo 50 mg

    Directory of Open Access Journals (Sweden)

    María Olga Valdés Bendoyro

    Full Text Available Se desarrolló el estudio de estabilidad de las tabletas de propiltiouracilo 50 mg y se determinó su fecha de vencimiento. Este estudio se realizó por los métodos de vida de estante y de estabilidad acelerada mediante cromatografía líquida de alta eficiencia, validados en el Centro de Investigación y Desarrollo de Medicamentos. El estudio de vida de estante se desarrolló por un periodo de 24 meses a temperatura ambiente; mientras que el estudio de estabilidad acelerada se efectuó sometiendo el producto a la influencia de la luz, la humedad y la temperatura; se realizó el análisis durante 3 meses, para los 2 primeros y durante 6 meses para el estudio de la temperatura. La formulación de propiltiouracilo tabletas 50 mg cumplió con las especificaciones de calidad descritas en la farmacopea. Los resultados del estudio de estabilidad por vida de estante después de transcurridos los 24 meses indicaron que el producto mantenía los parámetros que determinan su calidad durante ese tiempo, y en los estudios acelerados no se observó degradación significativa del producto. Se estableció 2 años como fecha de vencimiento en las condiciones señaladas.

  13. Formability of a wrought Mg alloy evaluated by impression testing

    Energy Technology Data Exchange (ETDEWEB)

    Mohamed, Walid; Gollapudi, Srikant; Charit, Indrajit; Murty, K. Linga

    2018-01-17

    This study is focused on furthering our understanding of the different factors that influence the formability of Magnesium alloys. Towards this end, formability studies were undertaken on a wrought Mg-2Zn-1Mn (ZM21) alloy. In contrast to conventional formability studies, the impression testing method was adopted here to evaluate the formability parameter, B, at temperatures ranging from 298 to 473 K. The variation of B of ZM21 with temperature and its rather limited values were discussed in the light of different deformation mechanisms such as activation of twinning, slip, grain boundary sliding (GBS) and dynamic recrystallization (DRX). It was found that the material characteristics such as grain size, texture and testing conditions such as temperature and strain rate, were key determinants of the mechanism of plastic deformation. A by-product of this analysis was the observation of an interesting correlation between the Zener-Hollomon parameter, Z, and the ability of Mg alloys to undergo DRX.

  14. Grain Growth in Nanocrystalline Mg-Al Thin Films

    Energy Technology Data Exchange (ETDEWEB)

    Kruska, Karen; Rohatgi, Aashish; Vemuri, Venkata Rama Ses; Kovarik, Libor; Moser, Trevor H.; Evans, James E.; Browning, Nigel D.

    2017-10-05

    An improved understanding of grain growth kinetics in nanocrystalline materials, and in metals and alloys in general, is of continuing interest to the scientific community. In this study, Mg - Al thin films containing ~10 wt.% Al and with 14.5 nm average grain size were produced by magnetron-sputtering and subjected to heat-treatments. The grain growth evolution in the early stages of heat treatment at 423 K (150 °C), 473 K (200 °C) and 573K (300 °C) was observed with transmission electron microscopy and analyzed based upon the classical equation developed by Burke and Turnbull. The grain growth exponent was found to be 7±2 and the activation energy for grain growth was 31.1±13.4 kJ/mol, the latter being significantly lower than in bulk Mg-Al alloys. The observed grain growth kinetics are explained by the Al supersaturation in the matrix and the pinning effects of the rapidly forming beta precipitates and possibly shallow grain boundary grooves. The low activation energy is attributed to the rapid surface diffusion which is dominant in thin film systems.

  15. Formkoexistenz in $^{32}$Mg: entdeckung des angeregten 0$^{+}$ zustands

    CERN Document Server

    Wimmer, Kathrin

    2010-01-01

    The evolution of shell structure in exotic nuclei as a function of proton (${Z}$) and neutron (${N}$) number is currently at the center of many theoretical and experimental investigations. It has been realized that the interaction of the last valence protons and neutrons, in particular the monopole component of the residual interaction between those nucleons, can lead to significant shifts in the single-particle energies, leading to the collapse of classic shell closures and the appearance of new shell gaps. The “Island of Inversion” around $^{32}$Mg, which is one of the most studied phenomena in the nuclear chart, is a well known example for such changes in nuclear structure. In this region of neutron-rich nuclei around the magic number${ N}$ = 20 strongly deformed ground states in Ne, Na, and Mg isotopes have been observed. Due to the reduction of the ${N}$ = 20 shell gap quadrupole correlations can enable low-lying deformed 2${p}$ − 2${h}$ intruder states from the ${fp}$-shell to compete with spheric...

  16. Sexual asthenia: Tradamixina versus Tadalafil 5 mg daily

    Science.gov (United States)

    2012-01-01

    Background Reduced libido is widely considered the most prominent symptomatic reflection of low testosterone (T) levels in men. Testosterone deficiency (TD) afflicts approximately 30% of men aged 40-79 years. This study seeks to evaluate the effect of a new natural compound “tradamixina “in order to improve male sexual function in elderly men, particularly libido and possible erectile dysfunction, versus administration of tadalafil 5 mg daily. Methods Seventy patients (67.3± 3.7 years) with stable marital relations and affected by reduced libido, with or without erectile dysfunction were recruited. They were randomly separated in 2 groups A-B of 35. Group A was administered twice a day a new compound “Tradamixina” (150 mg of Alga Ecklonia Bicyclis, 396 mg of Tribulus Terrestris and 144 mg of D-Glucosamine and N-Acetyl-D-Glucosamine) for two months, while Group B was administered tadalafil 5 mg daily, for two months. At visit and after 60 days of treatment patients were evaluated by means of detailed medical and sexual history, clinical examination, laboratory investigations (Total and Free T), instrumental examination (NPTR- nocturnal penile tumescence and rigidity test- with Rigiscan). Patients completed a self-administered IIEF questionnaire (The international index of erectile function) and SQoLM questionnaire (Sexual quality of life Questionnarie-Male). The results pre and post treatment were compared by Student t test (p<0.005). Results After 2 months of treatment in group A serum TT levels (230±18 ng/dl vs 671±14 ng/dl ) and FT levels(56± 2.4 pg/ml vs 120± 3.9pg/ml) increased, while in group B serum TT levels (245±12 ng/dl vs 247±15 ng/dl ) and FT levels(53± 0.3 pg/ml vs 55± 0.5pg/ml) increased not statistically significant. The patient’s numbers with negative NPTR improved after treatment in group A and B (15 vs 18 and 13 vs 25 respectively). The IIEF total score in group A increased after treatment with tradamixina (15±1.5 vs 29.77±1

  17. Abnormal devitrification behavior and mechanical response of cold-rolled Mg-rich Mg-Cu-Gd metallic glasses

    International Nuclear Information System (INIS)

    Lee, J.I.; Kim, J.W.; Oh, H.S.; Park, J.S.; Park, E.S.

    2016-01-01

    Abnormal devitrification behavior and mechanical response of Mg 75 Cu 15 Gd 10 (relatively strong glass former with higher structural stability) and Mg 85 Cu 5 Gd 10 (relatively fragile glass former with lower structural stability) metallic glasses, fabricated by repeated forced cold rolling, have been investigated. When metallic glasses were cold-rolled up to a thickness reduction ratio of ∼33%, the heat of relaxation (ΔH relax. ) below T g of the cold-rolled specimens was reduced, which indicates the formation of local structural ordering via cold rolling due to stress-induced relaxation. The local structural ordering results in abnormal devitrification behavior, such as higher resistance of glass-to-supercooled liquid transition and delayed growth, in the following heat treatment due to increased nuclei density and pinning site. In particular, the fragility index, m, could assist in understanding structural stability and local structural variation by mechanical processing as well as compositional tuning. Indeed, we examine the shear avalanche size to rationalize the variation of the deformation unit size depending on the structural instability before and after cold rolling. The deformation mode in Mg 85 Cu 5 Gd 10 metallic glass might change from self-organized critical state to chaotic state by cold rolling, which results in unique hardening behavior under the condition for coexisting well distributed local structural ordering and numerous thinner shear deformed areas. These results would give us a guideline for atomic scale structural manipulation of metallic glasses, and help develop novel metallic glass matrix composites with optimal properties through effective mechanical processing as well as heat treatment.

  18. Estudio de estabilidad de tabletas de propiltiouracilo 50 mg Study of the 50 mg Propylthiouracil tablets stability

    Directory of Open Access Journals (Sweden)

    María Olga Valdés Bendoyro

    2010-03-01

    Full Text Available Se desarrolló el estudio de estabilidad de las tabletas de propiltiouracilo 50 mg y se determinó su fecha de vencimiento. Este estudio se realizó por los métodos de vida de estante y de estabilidad acelerada mediante cromatografía líquida de alta eficiencia, validados en el Centro de Investigación y Desarrollo de Medicamentos. El estudio de vida de estante se desarrolló por un periodo de 24 meses a temperatura ambiente; mientras que el estudio de estabilidad acelerada se efectuó sometiendo el producto a la influencia de la luz, la humedad y la temperatura; se realizó el análisis durante 3 meses, para los 2 primeros y durante 6 meses para el estudio de la temperatura. La formulación de propiltiouracilo tabletas 50 mg cumplió con las especificaciones de calidad descritas en la farmacopea. Los resultados del estudio de estabilidad por vida de estante después de transcurridos los 24 meses indicaron que el producto mantenía los parámetros que determinan su calidad durante ese tiempo, y en los estudios acelerados no se observó degradación significativa del producto. Se estableció 2 años como fecha de vencimiento en las condiciones señaladas.Autors developed a stability study of 50 mg Propylthiouracil tablets and determination of its expiry date. This study was conducted by fixed life methods and of accelerated stability by high-performance liquid chromatography, validated in Drugs Research and Development Center. Fixed life study was conducted during 24 months at room temperature; whereas the accelerated stability study was conducted exposing the product to light influence, humidity and temperature; during 3 months a analysis was performed for the two first ones and over 6 months in the case of temperature study. Propylthiouracil formula (50 mg tablets fulfilled the quality specifications described in Pharmacopeia. Results of stability study by fixed life after 24 monhts showed that thr product maintain the parameter determining

  19. In-situ thermal analysis and macroscopical characterization of Mg-xCa and Mg-0.5Ca-xZn alloy systems

    Energy Technology Data Exchange (ETDEWEB)

    Farahany, Saeed [Department of Materials Engineering, Faculty of Mechanical Engineering, Universiti Teknologi Malaysia, 81310 Johor Bahru, Johor (Malaysia); Bakhsheshi-Rad, Hamid Reza, E-mail: Rezabakhsheshi@gmail.com [Department of Materials Engineering, Faculty of Mechanical Engineering, Universiti Teknologi Malaysia, 81310 Johor Bahru, Johor (Malaysia); Idris, Mohd Hasbullah [Department of Materials Engineering, Faculty of Mechanical Engineering, Universiti Teknologi Malaysia, 81310 Johor Bahru, Johor (Malaysia); Abdul Kadir, Mohammed Rafiq [Medical Implants Technology Group, Universiti Teknologi Malaysia, 81310 Johor Bahru, Johor (Malaysia); Department of Biomechanics and Biomedical Materials, Faculty of Biomedical Engineering and Health Sciences, Universiti Teknologi Malaysia, 81310 Johor Bahru, Johor (Malaysia); Lotfabadi, Amir Fereidouni [Department of Manufacturing and Industrial Engineering, Faculty of Mechanical Engineering, Universiti Teknologi Malaysia, 81310 Johor Bahru, Johor (Malaysia); Ourdjini, Ali [Department of Materials Engineering, Faculty of Mechanical Engineering, Universiti Teknologi Malaysia, 81310 Johor Bahru, Johor (Malaysia)

    2012-01-10

    Highlights: Black-Right-Pointing-Pointer The effect of Ca and Zn addition on Mg-Ca and Mg-Ca-Zn were investigated. Black-Right-Pointing-Pointer Ca and Zn addition decreased solid fraction at coherency point. Black-Right-Pointing-Pointer T{sub N}-T{sub DCP} increased by adding Ca and Zn in Mg-Ca and Mg-Ca-Zn, respectively. Black-Right-Pointing-Pointer Three reactions were detected when Zn/Ca atomic ratio less than 1.25 in Mg-Ca-Zn. Black-Right-Pointing-Pointer A new peak Mg{sub 51}Zn{sub 20} was identified in Mg-0.5Ca-9Zn in addition of other peaks. - Abstract: This research described the identification phases by thermal analysis and microscopy inspection of Mg-xCa and Mg-0.5%Ca-xZn alloys that were solidified at slow cooling rate. Analysis of cooling curve after Ca addition shows the evolution of the Mg{sub 2}Ca intermetallic phase at around 520 Degree-Sign C in addition to {alpha}-Mg phase. First derivative curves of alloys after the addition of Zn to Mg-0.5Ca alloy reveals three peaks related to {alpha}-Mg, Mg{sub 2}Ca and Ca{sub 2}Mg{sub 6}Zn{sub 3} for alloys that have Zn/Ca atomic ratio less than 1.23. The peak of Mg{sub 2}Ca reaction on the first derivative curves disappeared for alloys containing Zn/Ca ratio more than 1.23. A new peak was also observed at 330 Degree-Sign C for Mg-0.5Ca-9Zn which was identified as Mg{sub 51}Zn{sub 20}. Solid fraction at coherency point decreased with increasing Ca and Zn elements. However, coherency time and difference between the nucleation and coherency temperatures (T{sub N}-T{sub DCP}) increased by adding Ca and Zn in Mg-Ca and Mg-Ca-Zn systems.

  20. Equilibrium between (Li,Na,K,Mg)-carbonate melt, gaseous CO

    NARCIS (Netherlands)

    Velden, P.F. van

    1967-01-01

    Considerable amounts of MgCO3 may appear in alkali metal carbonate melts in contact with MgO and carbon dioxide gas. The equilibrium between dissolved MgCO3, MgO and carbon dioxide gas has been studied. The results satisfactorily obey thermodynamic theory based upon a melt