NMR measurements in milled GdCo2 and GdFe2 intermetallic compounds

International Nuclear Information System (INIS)

Tribuzy, C.V.B.; Guimaraes, A.P.; Biondo, A.; Larica, C.; Alves, K.M.B.

1998-12-01

We have used the nuclear magnetic resonance technique to study the magnetic and structural properties of the Gd-Co and Gd-Fe metallic systems, starting with the C15 laves phase intermetallic compounds, and submitting them to a high energy milling process. This leads to the amorphization of the samples, as determined by the X-ray diffraction spectra. For the Gd-Co system the NMR study used the 59 Co nucleus; in the Gd-Fe system, 155,157 Gd and 57 Fe were used. Both systems showed segregation of the pure elements, after a few hours of milling. In the Gd-Co system, a single line, of increasing width, was observed in the 59 Co spectrum. In the Gd-Fe system, the 155 Gd and 157 Gd resonances show three lines, arising from electrical quadrupole interaction. With increasing milling time, the lines broaden, and extra lines appear attributed to a cubic phase of Gd; this interpretation is supported by the X-ray analysis of the samples. The 57 Fe NMR spectrum of this system also informs on the direction of magnetization of the samples in the early stages of milling. From 1 h to 7 h of milling, a spectrum of α-Fe was observed. The study of the NMR line intensity as a function of radio frequency (r.f.) power in Gd Co 2 suggests the existence of regions of the samples with different degrees of disorder. We have observed the persistence of NMR signals from the original intermetallic compounds in the samples with up to 10 h and 7 h of milling, respectively, for Gd Co 2 and Gd Fe 2 . (author)

Summary and Comparison of the 2016 Billion-Ton Report with the 2011 U.S. Billion-Ton Update

Energy Technology Data Exchange (ETDEWEB)

None

2016-06-01

In terms of the magnitude of the resource potential, the results of the 2016 Billion-Ton Report (BT16) are consistent with the original 2005 Billion-Ton Study (BTS) and the 2011 report, U.S. Billion-Ton Update: Biomass Supply for a Bioenergy and Bioproducts Industry (BT2. An effort was made to reevaluate the potential forestland, agricultural, and waste resources at the roadside, then extend the analysis by adding transportation costs to a biorefinery under specified logistics assumptions to major resource fractions.

Enhanced flux pinning by BaZrO3 and (Gd,y)2O3 nano-structures in metal organic chemical vapor deposited GdYBCO high temperature superconductor tapes

Energy Technology Data Exchange (ETDEWEB)

Chen, Y [SuperPower Incorporated, Schenectady, New York; Selvamanickam, V. [SuperPower Incorporated, Schenectady, New York; Paranthaman, Mariappan Parans [ORNL; Cantoni, Claudia [ORNL; Aytug, Tolga [ORNL; Goyal, Amit [ORNL; Lee, Dominic F [ORNL; Specht, Eliot D [ORNL; Zuev, Yuri L [ORNL; Zhang, Yifei [ORNL

2009-01-01

We have formed BaZrO3 nano-columns and (Gd,Y)2O3 nano-precipitates in reel-to-reel MOCVD processed (Gd,Y)Ba2Cu3O7-x coated conductors and increased the critical currents (Ic) of the conductors in applied magnetic fields to remarkable levels. A (Gd,Y)Ba2Cu3O7-x tape of 1m length with 6.5% Zr-additions and 30% composition rich in both Gd and Y showed Ic values of 813 A/cm-width at (self-field, 77K) and above 186 A/cm-width at (1T, 77K). The strongly enhanced flux pinning over a wide range of magnetic field orientations can be attributed to the bidirectionally aligned defect structures of BaZrO3 and (Gd,Y)2O3 created by optimized MOCVD conditions.

Electrical and optical characterization of green synthesized Gd{sub 2}S{sub 3}

Energy Technology Data Exchange (ETDEWEB)

Paul, Somnath, E-mail: somnathpaul459@gmail.com; Sarkar, A. [Dept of Physics, Bijoy Krishna Girls’ College, 5/3, M. G. Road, Howrah-711101 (India)

2016-05-06

Gadolinium sulphide (Gd{sub 2}S{sub 3}) is a magnetic semiconductor with large band gap. Gd{sub 2}S{sub 3} was synthesized following chemical and green techniques. Later process provides good stability of the nano clusters (NC) due to in-situ capping of Gd{sub 2}S{sub 3} NC. It has been found that the optical band gap in Gd{sub 2}S{sub 3} developed by green synthesis is lowered considerably over that in chemically synthesized Gd{sub 2}S{sub 3}. The green agencies used in this work are Jatropha Latex and dilute Garlic extract; both are enriched in sulphur and other organic polymer molecules. Simple observation shows that Gd{sub 2}S{sub 3} NC retains residual magnetization. In this work optical and electrical characterization of the developed Gd{sub 2}S{sub 3} specimens are carried out. The overall results obtained are good.

Ni3d-Gd4f correlation effects on the magnetic behaviour of GdNi

Energy Technology Data Exchange (ETDEWEB)

Paulose, P L [Tata Inst. of Fundamental Research, Bombay (India); Patil, Sujata [Tata Inst. of Fundamental Research, Bombay (India); Mallik, R [Tata Inst. of Fundamental Research, Bombay (India); Sampathkumaran, E V [Tata Inst. of Fundamental Research, Bombay (India); Nagarajan, V [Tata Inst. of Fundamental Research, Bombay (India)

1996-07-01

The results of magnetization and heat-capacity measurements on the alloys, Gd{sub 1-x}Y{sub x}Ni (x=0.0, 0.25, 0.5, 0.75 and 0.9) are reported. The data suggest that there is a Gd induced magnetic moment on Ni, which may in turn enhance Gd-Gd exchange interaction strength in GdNi. The induced moment (on Ni) apparently exhibits itinerant ferromagnetism in the magnetically ordered state of GdNi. (orig.).

Evaluation of Gd and Gd{sup 159} as new approaches for cancer treatment

Energy Technology Data Exchange (ETDEWEB)

Galvao, I.; Neves, M.J., E-mail: nevesmj@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil). Grupo de Desenvolvimento de Radiofarmacos; Santos, R.G., E-mail: santosr@cdtn.br [Instituto Nacional de Ciencia e Tecnologia em Medicina Molecular (INCT-MM), Belo Horizonte, MG (Brazil)

2011-07-01

Metal compounds have shown many biological activities and have been successfully used as anticancer agents such cisplatin. Actually gadolinium (Gd) complexed with a porphyrin Motexafin (MGd) has been investigated as redox-active compound for treatment of cancer. 1{sup 59G}d decays by beta emission with an energy of 970 keV and half-life of 18.59 hours. The de-excitation can be via gamma ray and internal conversion electron emission followed by auger electrons and x rays. Considering all of this 1{sup 59G}d could be a interesting radionuclide to be as a radio therapeutical agent. The aims of this works were to evaluate the cytotoxicity of Gd and 1{sup 59G}d on malignant brain tumors such as glioblastoma multiform, the most frequent brain tumors which has a very poor prognosis. For this purpose, it was used human glioblastoma cell lines T98 (mutant p53) and U87 (wild-type p53) to investigate the cytotoxicity of gadolinium on cell metabolism by MTT assay and also morphological changes, chromatin condensation by DAPI assay and ROS generation. Gadolinium was able to decrease cell viability, the cells presented morphological changes like round shapes and blebs formation after cell treatment with 5x10{sup -6}M of Gd. Nuclear changing and ROS generation occurred in a dose dependent way indicating the cytotoxic effect of Gd. Treatment with 1{sup 59G}d increased all of changes observed with treatment with Gd. These results state for an additive effect of metal toxicity and radioactivity inducing ROS generation as the main mechanism of anti tumoral action of 1{sup 59G}d. The results obtained indicated that the radioactive analogues of Gd have increased cytotoxic effects and gadolinium can be a metal of choice for development of new drugs for cancer treatment. (author)

Sneak Peek to the 2016 Billion-Ton Report

Energy Technology Data Exchange (ETDEWEB)

None

2016-06-01

The 2005 Billion-Ton Study became a landmark resource for bioenergy stakeholders, detailing for the first time the potential to produce at least one billion dry tons of biomass annually in a sustainable manner from U.S. agriculture and forest resources. The 2011 U.S. Billion-Ton Update expanded and updated the analysis, and in 2016, the U.S. Department of Energy’s Bioenergy Technologies Office plans to release the 2016 Billion-Ton Report: Advancing Domestic Resources for a Thriving Bioeconomy.

Diagnosis of urinary bladder carcinoma by MR: Improvement through Gd-DTPA?

International Nuclear Information System (INIS)

Sparenberg, A.; Hamm, B.; Samberger, V.; Wolf, K.J.; Hammerer, P.

1991-01-01

85 patients suffering from urinary bladder carcinoma were examined by magnetic resonance imaging in a prospective study. Following precontrast diagnosis, 15 patients were given an intravesicular application of gadolinium-DTPA (Gd-DTPA). Another 35 patients received an intravenous bolus of Gd-DTPA. A diagnostic advantage was achieved in only 2 of 15 tumours by using intravesicular contrast application. Compared to the precontrast diagnosis, a 14% improvement from 69% (precontrast) to 83% (contrast medium) was seen with Gd-DTPA applied intravenously in the diagnosis of the tumour stage. The diagnostic gain lies in the improved tumour recognition, the improved demarcation of papillary, non-muscle-infiltrating tumours and in the more definite diagnosis of infiltration into neighbouring organs and the pelvic wall. Demarcation of perivesicular fatty infiltration is rendered more difficult by Gd-DTPA. (orig.) [de

Calculation of the band structure of GdCo2, GdRh2 e GdIr2 by the APW method

International Nuclear Information System (INIS)

Carvalho, J.A.B. de.

1974-03-01

The band structure of GdCo 2 , GdRh 2 , GdIr 2 has been calculated by the APW method. A histogram of the density of states is presented for each compound. The bands are transition-metal-like, with s-d hybridization near the Fermi level. The 5d character near the Fermi level increases as one goes from Co to Ir

The Structural Evolution of (Gd, Y)Ba2Cu3Ox Tapes With Zr Addition Made by Metal Organic Chemical Vapor Deposition

Energy Technology Data Exchange (ETDEWEB)

Lei, CH; Galstyan, E; Chen, YM; Shi, T; Liu, YH; Khatri, N; Liu, JF; Xiong, XM; Majkic, G; Selvamanickam, V

2013-06-01

Structural analysis of (Gd, Y) Ba2Cu3Ox tapes with Zr addition made by metal organic chemical vapor deposition has been conducted with transmission electron microscopy and X-ray diffraction. Zr content in the films was varied from 0 to 25% in the precursor. In all Zr-doped films, self-assembled nanocolumnar structures of BaZrO3 (BZO) were observed along the c-axis. The amount of BaZrO3 was found to increase steadily with Zr content. Additionally, planar BZO plates were found on the (001) plane of (Gd, Y) Ba2Cu3Ox film. The size and thickness of BZO plates were seen to increase with Zr doping level. Rare-earth copper oxide phases were observed to begin to emerge in the 20% Zr-doped film. Cross-sectional study of the interface between (Gd, Y)Ba2Cu3Ox and LaMnO3 cap layer revealed a thin discrete BZO layer on the LaMnO3 in the 20% Zr doped film.

The Role of TonB Gene in Edwardsiella ictaluri Virulence

Directory of Open Access Journals (Sweden)

Hossam Abdelhamed

2017-12-01

Full Text Available Edwardsiella ictaluri is a Gram-negative facultative intracellular pathogen that causes enteric septicemia in catfish (ESC. Stress factors including poor water quality, poor diet, rough handling, overcrowding, and water temperature fluctuations increase fish susceptibility to ESC. The TonB energy transducing system (TonB-ExbB-ExbD and TonB-dependent transporters of Gram-negative bacteria support active transport of scarce resources including iron, an essential micronutrient for bacterial virulence. Deletion of the tonB gene attenuates virulence in several pathogenic bacteria. In the current study, the role of TonB (NT01EI_RS07425 in iron acquisition and E. ictaluri virulence were investigated. To accomplish this, the E. ictaluri tonB gene was in-frame deleted. Growth kinetics, iron utilization, and virulence of the EiΔtonB mutant were determined. Loss of TonB caused a significant reduction in bacterial growth in iron-depleted medium (p > 0.05. The EiΔtonB mutant grew similarly to wild-type E. ictaluri when ferric iron was added to the iron-depleted medium. The EiΔtonB mutant was significantly attenuated in catfish compared with the parent strain (21.69 vs. 46.91% mortality. Catfish surviving infection with EiΔtonB had significant protection against ESC compared with naïve fish (100 vs. 40.47% survival. These findings indicate that TonB participates in pathogenesis of ESC and is an important E. ictaluri virulence factor.

Effect of Al2Gd on microstructure and properties of laser clad Mg–Al–Gd coatings

International Nuclear Information System (INIS)

Chen, Hong; Zhang, Ke; Yao, Chengwu; Dong, Jie; Li, Zhuguo; Emmelmann, Claus

2015-01-01

Highlights: • Mg–Al–Gd coatings with different Gd contents were fabricated by fiber laser cladding. • Chemical compositions and crystal structures of the second phases were characterized. • Dispersion of Al 2 Gd led to further grain refining and elevated mechanical properties. • Al 2 Gd improved high-temperature performances by preventing tiny liquation. - Abstract: In order to investigate the effects of Gd addition on the microstructures and properties of magnesium coatings, the Mg–7.5Al–xGd (x = 0, 2.5, 5.0 and 7.5 wt.%) coatings on cast magnesium alloy were fabricated by laser cladding with wire feeding. The results indicated that the gadolinium (Gd) addition led to the formation of a cubic Al 2 Gd phase as well as suppressed the precipitation of eutectic Mg 17 Al 12 phase. The laser clad coating containing nominally 7.5 wt.% Gd presented the highest microhardness, ultimate tensile strength and yield strength at both room temperature and high temperatures. The enhancement of heat resistant capacities was chiefly attributed to the existence of thermally stable Al 2 Gd particles, which prevented tiny liquation of eutectic phases along the grain boundaries and made great contributions on maintaining high yield ratio during high-temperature deformation

A comparison of Gd-BOPTA and Gd-DOTA for contrast-enhanced MRI of intracranial tumours

International Nuclear Information System (INIS)

Colosimo, C.; Knopp, M.V.; Barreau, X.; Gerardin, E.; Kirchin, M.A.; Guezenoc, F.; Lodemann, K.P.

2004-01-01

A two-centre intra-individual crossover study was performed in 23 patients with suspected high-grade glioma or metastases to assess and compare the safety and enhancement characteristics of two different MRI contrast media (gadobenate dimeglumine, Gd-BOPTA and gadoterate meglumine, Gd-DOTA) at equivalent doses of 0.1 mmol/kg body weight. T1-weighted spin-echo (SE) and T2-weighted fast SE images were obtained before and T1-weighted images 0, 2, 4, 6, 8 and 15 min after injection. T1-weighted images with magnetisation transfer contrast were acquired 12 min after injection. Qualitative assessment by blinded, off-site readers (reader 1: 19 patients; reader 2: 21) and on-site investigators (23) revealed significant (P ≤0.005) overall preference for Gd-BOPTA over Gd-DOTA for contrast enhancement (Gd-BOPTA preferred in 18, 15 and 18 cases; Gd-DOTA in 0, 1 and 1 and no preference in 1, 5 and 4; off-site readers 1 and 2, and on-site investigators, respectively). A similar significant preference for Gd-BOPTA was expressed by off-site readers and on-site investigators for lesion-to-brain contrast, lesion delineation, internal lesion structure, and overall image preference. Quantitative assessment by off-site readers revealed significantly (p<0.05) greater lesion enhancement with Gd-BOPTA than with Gd-DOTA at all times from 2 min after injection. (orig.)

Expression of OATP1B3 determines uptake of Gd-EOB-DTPA in hepatocellular carcinoma

OpenAIRE

Narita, Masato; Hatano, Etsuro; Arizono, Shigeki; Miyagawa-Hayashino, Aya; Isoda, Hiroyoshi; Kitamura, Koji; Yasuchika, Kentaro; Nitta, Takashi; Uemoto, Shinji

2009-01-01

Background: Gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid (Gd-EOB-DTPA) is an MRI contrast agent with perfusion and hepatoselective properties. The purpose of the study was to examine uptake of Gd-EOB-DTPA in the hepatobiliary phase in hepatocellular carcinoma (HCC). Methods: A retrospective analysis of 22 patients with HCC who underwent preoperative Gd-EOB-DTPA-enhanced MRI was performed. Enhancement ratios (ERs) and expression levels of the organic anion transporter (OATP) 1B3...

Thermodynamic calculation of Al-Gd and Al-Gd-Mg phase equilibria checked by key experiments

International Nuclear Information System (INIS)

Groebner, J.; Kevorkov, D.; Schmid-Fetzer, R.

2001-01-01

The binary Al-Gd and the ternary Al-Gd-Mg systems were calculated using the Calphad method. It is demonstrated that previous interpretation of ternary liquidus temperatures below 700 C must be related to other phase equilibria. The actual ternary liquidus temperatures are much higher, up to some 600 C above the previous interpretation in literature. They are widely governed by the high-melting compounds Al 2 Gd and Al 3 Gd with liquidus surfaces stretching far into the ternary system. A small number of key experiments in this work confirmed the calculated liquidus temperature and the phase relations. The available experimental data in literature fit excellently with the calculation in the binary Al-Gd system. In the ternary Al-Gd-Mg system, which is shown in several sections of the phase diagram, a good agreement can be observed too, considering the necessary reinterpretation of the liquidus temperatures suggested by Rokhlin et al. Ternary solubilities were not found experimentally. The ternary compound Al 4 GdMg (τ) forms in a ternary peritectic reaction at 761 C. (orig.)

Effect of Al{sub 2}Gd on microstructure and properties of laser clad Mg–Al–Gd coatings

Energy Technology Data Exchange (ETDEWEB)

Chen, Hong; Zhang, Ke; Yao, Chengwu [Shanghai Key Lab of Materials Laser Processing and Modification, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240 (China); Dong, Jie [National Engineering Research Center of Light Alloy Net Forming, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240 (China); Li, Zhuguo, E-mail: lizg@sjtu.edu.cn [Shanghai Key Lab of Materials Laser Processing and Modification, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240 (China); Emmelmann, Claus [Institute of Laser and System Technologies, Hamburg University of Technology, Hamburg, 21073 (Germany)

2015-03-01

Highlights: • Mg–Al–Gd coatings with different Gd contents were fabricated by fiber laser cladding. • Chemical compositions and crystal structures of the second phases were characterized. • Dispersion of Al{sub 2}Gd led to further grain refining and elevated mechanical properties. • Al{sub 2}Gd improved high-temperature performances by preventing tiny liquation. - Abstract: In order to investigate the effects of Gd addition on the microstructures and properties of magnesium coatings, the Mg–7.5Al–xGd (x = 0, 2.5, 5.0 and 7.5 wt.%) coatings on cast magnesium alloy were fabricated by laser cladding with wire feeding. The results indicated that the gadolinium (Gd) addition led to the formation of a cubic Al{sub 2}Gd phase as well as suppressed the precipitation of eutectic Mg{sub 17}Al{sub 12} phase. The laser clad coating containing nominally 7.5 wt.% Gd presented the highest microhardness, ultimate tensile strength and yield strength at both room temperature and high temperatures. The enhancement of heat resistant capacities was chiefly attributed to the existence of thermally stable Al{sub 2}Gd particles, which prevented tiny liquation of eutectic phases along the grain boundaries and made great contributions on maintaining high yield ratio during high-temperature deformation.

Measurement of Gd content in (U,Gd)O2 using thermal gravimetric analysis

International Nuclear Information System (INIS)

Kim, Keon Sik; Yang, Jae Ho; Kang, Ki Won; Song, Kun Woo; Kim, Gil Moo

2004-01-01

We propose a simple and precise method for measuring the Gd content in the (U,Gd)O 2 pellet by only measuring the weight variation of the pellet during thermal heat treatment in air. The (U,Gd)O 2 fuel pellets were oxidized at 475 deg. C, subsequently heat treated at 1300 deg. C, and then cooled to room temperature in air. The accompanying weight variations were measured using thermo gravimetric analysis (TGA). The measured weight variations were mathematically analyzed with reference to the successive phase reactions during the heat treatment. This method provides an advantage in that the rare-earth element content including Gd can be measured using relatively simple equipment such as an electric furnace and a balance

CW laser properties of Nd:GdYAG, Nd:LuYAG, and Nd:GdLuAG mixed crystals

Science.gov (United States)

Di, J. Q.; Xu, X. D.; Li, D. Z.; Zhou, D. H.; Wu, F.; Zhao, Z. W.; Xu, J.; Tang, D. Y.

2011-10-01

Three mixed crystals, Nd:GdYAG, Nd:LuYAG, and Nd:GdLuAG, were grown by Czochralski method. We report the continuous-wave (CW) Nd:GdYAG, Nd:LuYAG, and Nd:GdLuAG laser operation under laser diode pumping. The maximum output powers are 4.11, 5.31, and 7.47 W, with slope efficiency of 73.0, 55.3, and 57.1%, respectively. With replacing Lu3+ or Y3+ ions with large Gd3+ ions, the pump efficiency increases.

Peculiar features of thermal emission of GdB4 and GdB6 single crystals

International Nuclear Information System (INIS)

Ostrovskij, E.K.; Taran, A.A.; Kovalev, A.V.; Tkachenko, V.F.; Dudnik, E.M.; Matvienko, A.A.

1990-01-01

Thermoemission parameters of single crystals (410) GdB 4 and (110) GdB 6 are studied. Work function is calculated by total current. It is stated that work function of GdB 6 within temperature range of 1500-1880 K after 80 h of annealing varies from 2.95 to 3.10 eV practically with the same temperature coefficient as GdB 4 , i.e. 4.1x10 -4 eV/K. It is shown that single crystal gadolinium hexaboride during the high-temperature annealing in the surface region (∼70 mm) is transformed into gadolinium tetraboride. Influence of free air has been first studied on the GdB 4 emissivity which is determined to increase to p=1.3x10 -2 Pa within the range of T=1640-1840 K

The effect of Gd doping on the electrical and photoelectrical properties of Gd:ZnO/p-Si heterojunctions

Energy Technology Data Exchange (ETDEWEB)

Baturay, Silan [Department of Physics, Faculty of Science, Dicle University, 21280 Diyarbakir (Turkey); Ocak, Yusuf Selim, E-mail: yusufselim@gmail.com [Department of Science, Faculty of Education, Dicle University, 21280 Diyarbakir (Turkey); Science and Technology Application and Research Center, Dicle University, 21280 Diyarbakir (Turkey); Kaya, Derya [Department of Physics, Institute of Natural Applied Sciences, Dicle University, 21280 Diyarbakir (Turkey)

2015-10-05

Highlights: • Undoped and Gd doped ZnO thin films were deposited onto p-Si semiconductor. • The Gd:ZnO/p-Si heterojunctions were compared with undoped ZnO/p-Si heterojunction. • A strong effect of Gd doping on the performance of the devices were reported. - Abstract: Undoped ZnO thin films, as well as 1%, 3% and 5% Gd-doped ZnO films, were deposited on p-type Si using spin coating. The structural properties of these thin films were analysed using X-ray diffraction, and the current–voltage (I–V) and capacitance–voltage (C–V) characteristics of the Gd:ZnO/p-Si heterojunctions were compared with those of the undoped ZnO/p-Si heterojunctions. We found that Gd doping had a strong effect on the performance of the devices, and that the Gd:ZnO/p-Si heterojunctions formed with 1% Gd-doped ZnO were the most strongly rectifying, and had the highest barrier height and the lowest series resistance. Furthermore, the I–V measurements of the 1% Gd-doped ZnO/p-Si heterojunction exhibited the strongest response to light.

Improved sensitivity for W-band Gd(III)-Gd(III) and nitroxide-nitroxide DEER measurements with shaped pulses

Science.gov (United States)

Bahrenberg, Thorsten; Rosenski, Yael; Carmieli, Raanan; Zibzener, Koby; Qi, Mian; Frydman, Veronica; Godt, Adelheid; Goldfarb, Daniella; Feintuch, Akiva

2017-10-01

Chirp and shaped pulses have been recently shown to be highly advantageous for improving sensitivity in DEER (double electron-electron resonance, also called PELDOR) measurements due to their large excitation bandwidth. The implementation of such pulses for pulse EPR has become feasible due to the availability of arbitrary waveform generators (AWG) with high sampling rates to support pulse shaping for pulses with tens of nanoseconds duration. Here we present a setup for obtaining chirp pulses on our home-built W-band (95 GHz) spectrometer and demonstrate its performance on Gd(III)-Gd(III) and nitroxide-nitroxide DEER measurements. We carried out an extensive optimization procedure on two model systems, Gd(III)-PyMTA-spacer-Gd(III)-PyMTA (Gd-PyMTA ruler; zero-field splitting parameter (ZFS) D ∼ 1150 MHz) as well as nitroxide-spacer-nitroxide (nitroxide ruler) to evaluate the applicability of shaped pulses to Gd(III) complexes and nitroxides, which are two important classes of spin labels used in modern DEER/EPR experiments. We applied our findings to ubiquitin, doubly labeled with Gd-DOTA-monoamide (D ∼ 550 MHz) as a model for a system with a small ZFS. Our experiments were focused on the questions (i) what are the best conditions for positioning of the detection frequency, (ii) which pump pulse parameters (bandwidth, positioning in the spectrum, length) yield the best signal-to-noise ratio (SNR) improvements when compared to classical DEER, and (iii) how do the sample's spectral parameters influence the experiment. For the nitroxide ruler, we report an improvement of up to 1.9 in total SNR, while for the Gd-PyMTA ruler the improvement was 3.1-3.4 and for Gd-DOTA-monoamide labeled ubiquitin it was a factor of 1.8. Whereas for the Gd-PyMTA ruler the two setups pump on maximum and observe on maximum gave about the same improvement, for Gd-DOTA-monoamide a significant difference was found. In general the choice of the best set of parameters depends on the D

Synthesis and Characterization of Hollow Magnetic Alloy (GdNi2, Co5Gd Nanospheres Coated with Gd2O3

Directory of Open Access Journals (Sweden)

Wang Li

2014-01-01

Full Text Available Uniform magnetic hollow nanospheres (GdNi2, Co5Gd coated with Gd2O3 have been successfully prepared on a large scale via a urea-based homogeneous precipitation method using silica (SiO2 spheres as sacrificed templates, followed by subsequent heat treatment. Nitrogen sorption measurements and scanning electron microscope reveal that these hollow-structured magnetic nanospheres have the mesoporous shells that are composed of a large amount of uniform nanoparticles. After reduction treatment, these nanoparticles exhibit superparamagnetism that might have potential applications in medicine. Furthermore, the developed synthesis route may provide an important guidance for the preparation of other multifunctional hollow spherical materials.

Giant magnetocaloric effect in Gd5(Si2Ge2 alloy with low purity Gd

Directory of Open Access Journals (Sweden)

Cleber Santiago Alves

2004-12-01

Full Text Available Gd5(Ge1-xSi x, x < 4 based alloys are potential candidates for magnetic refrigeration in the range ~20 - ~290 K. However, one of the greatest obstacles for the use of that technology in large scale is the utilization of high pure Gd metal (99.99 wt. (% to produce the GdGeSi alloys, since the impurity elements decrease the intensity of the magnetocaloric effect (EMC¹. In this work, we prove that annealing of the Gd5Ge2Si2 can promote remarkable values for the EMC in comparison to those obtained for the alloy with high pure Gd. Also, the as cast alloy and the annealed alloy are not monophasic, but have at least two crystalline phases in their microstructure. Results for X-ray analysis, optical and electronic microscopy and magnetization measurements are reported.

Phase-Transition and Magnetic Moment of the Gd3+ Ion in the Gd2Fe17 Compound

Institute of Scientific and Technical Information of China (English)

HAO Yan-Ming; FU Bin; ZHOU Yan; ZHAO Miao

2009-01-01

The structure and magnetic phase transitions of the Gd2Fe17 compound are investigated by using a differential thermal/thermogravimetric analyzer, x-ray diffraction, and magnetization measurements. The result shows that there are two phase structures for the Gd2Fe17 compound: the hexagonal Th2Ni17-type structure at high tem-peratures (above 1243℃), and the rhombohedrai Th2Zn17-type structure, respectively. A method to measure the magnetic moments of the Gd-sublattice and the Fe-sublattice in the Gd2Fe17 compound is presented. The moments of the Gd-sublattice and the Fe-sublattice in the Gd2Fe17 compound from 77 to 500 K are measured in this way with a vibrating sample magnetometer. A detailed discussion is presented.

Phantom and animal studies of a new hepatobiliary agent for MR imaging: comparison of Gd-DTPA-DeA with Gd-EOB-DTPA.

Science.gov (United States)

Yoshikawa, Kohki; Inoue, Yusuke; Akahane, Masaaki; Shimada, Morio; Itoh, Sayaka; Seno, Atsushi; Hayashi, Sanshin

2003-08-01

To investigate the characteristics of Gd-DTPA-DeA as a hepatobiliary contrast agent for MR imaging in comparison with those of Gd-EOB-DTPA. We undertook phantom experiments to assess T1 relaxivity for Gd-DTPA-DeA, Gd-EOB-DTPA, and Gd-DTPA in human plasma. For Gd-DTPA-DeA and Gd-EOB-DTPA, we evaluated the contrast effect in rats using an SPGR sequence. The contrast ratios of liver and abdominal aorta were measured up to 21 minutes after intravenous administration of the agents. Visualization of the bile duct and renal pelvis was also assessed. In human plasma, T1 relaxivity was similar for Gd-DTPA-DeA and Gd-EOB-DTPA, and higher than those for Gd-DTPA. Whereas the contrast ratio of liver peaked about five minutes after the injection of Gd-EOB-DTPA and was followed by a subsequent decline, a continuous rise was shown for Gd-DTPA-DeA, resulting in a larger maximal contrast effect. Contrast ratios of the abdominal aorta were larger for Gd-DTPA-DeA. Biliary excretion was observed for both agents but occurred earlier with Gd-EOB-DTPA. While renal excretion was shown for all rats three minutes after the injection of Gd-EOB-DTPA, it was not observed for Gd-DTPA-DeA. Gd-DTPA-DeA may be used as a hepatobiliary contrast agent and shows different pharmacokinetics from Gd-EOB-DTPA. Copyright 2003 Wiley-Liss, Inc.

The production and use of a 148Gd charged particle target in a spectroscopic study of 147Gd

International Nuclear Information System (INIS)

Massey, T.N.

1988-01-01

This thesis discusses the nuclear structure of 147 Gd elucidated by the neutron pickup reactions (p,d), (d,t) and ( 3 He,α) on the unstable 148 Gd target. The neutron pickup reaction on 148 Gd probes the two-particle-one-hole states by the pickup of neutrons in the shell model orbitals below the N = 82 gap and one-particle states by pickup of neutrons in shell model orbitals above the N = 82 gap. Our experiments will provide information on the location of neutron single-particle energies which can be used for shell-model calculations in the 146 Gd region. The 2-particle-1-hole (2p-1h) states which are probed directly by the neutron transfer reaction in the experiments with the 148 Gd target, will bear indirectly on the energies of one-hole states in 145 Gd. They will also provide information on the strongest single-particle states in 147 Gd because all the single-particle states in the 148 Gd target are partially occupied because of the mixing by the pairing interaction. 107 refs., 23 figs., 20 tabs

Radiation characteristics of GD-2 fuel

International Nuclear Information System (INIS)

Chrapciak, V.

2008-01-01

The assembly WWER-440 type Gd-2 has radial profile of enrichment and has 6 pins with Gd 2 O 3 . The maximal enrichment is 4.4%. Some analyses are done for assembly with flat enrichment (4.4%) and without Gd 2 O 3 . In this article are compared some characteristics (decay heat, some nuclide concentration, photon and gamma sources) for real Gd-2 assembly and for flat 4.4% assembly. The TRITON module (in SCALE 5.1) was used. (Author)

Evaluation of Gd and Gd159 as new approaches for cancer treatment

International Nuclear Information System (INIS)

Galvao, I.; Neves, M.J.

2011-01-01

Metal compounds have shown many biological activities and have been successfully used as anticancer agents such cisplatin. Actually gadolinium (Gd) complexed with a porphyrin Motexafin (MGd) has been investigated as redox-active compound for treatment of cancer. 1 59G d decays by beta emission with an energy of 970 keV and half-life of 18.59 hours. The de-excitation can be via gamma ray and internal conversion electron emission followed by auger electrons and x rays. Considering all of this 1 59G d could be a interesting radionuclide to be as a radio therapeutical agent. The aims of this works were to evaluate the cytotoxicity of Gd and 1 59G d on malignant brain tumors such as glioblastoma multiform, the most frequent brain tumors which has a very poor prognosis. For this purpose, it was used human glioblastoma cell lines T98 (mutant p53) and U87 (wild-type p53) to investigate the cytotoxicity of gadolinium on cell metabolism by MTT assay and also morphological changes, chromatin condensation by DAPI assay and ROS generation. Gadolinium was able to decrease cell viability, the cells presented morphological changes like round shapes and blebs formation after cell treatment with 5x10 -6 M of Gd. Nuclear changing and ROS generation occurred in a dose dependent way indicating the cytotoxic effect of Gd. Treatment with 1 59G d increased all of changes observed with treatment with Gd. These results state for an additive effect of metal toxicity and radioactivity inducing ROS generation as the main mechanism of anti tumoral action of 1 59G d. The results obtained indicated that the radioactive analogues of Gd have increased cytotoxic effects and gadolinium can be a metal of choice for development of new drugs for cancer treatment. (author)

GdF Suez, the real energy champion;GdF Suez, le vrai champion de l'energie

Energy Technology Data Exchange (ETDEWEB)

Dupin, L.

2010-09-15

During summer 2010, France discovered that she owned a second energy giant, GdF Suez, ranked number two as a power producer just behind EdF, but world number one in the energy domain thanks to the taking over of International Power (UK) in 2010. Until now, GdF Suez and EdF were confronting with each other in a fair game, keeping their respective seizure on their historical monopolies, gas for GdF Suez and electricity for EdF. From now onward the two giants have started an open fight on all markets, with the exception of nuclear energy for which the French government continues to favour EdF. This paper recalls the main steps of the last 15 years of GdF Suez progress, from the Suez investment bank in 1995 to the merger with GdF in 2008 and the acquisition of International Power in 2010. Then it makes a comparative portrait of both GdF Suez and EdF energy groups with their respective advantages and, finally, it ends with an interview of G. Mestrallet, president of GdF Suez who explains the strategy of his group. (J.S.)

Experimental MR imaging with Gd-DOTA: Preliminary results

International Nuclear Information System (INIS)

Schouman-Claeys, E.; Kien, P.; Caille, J.M.; Bonnemain, B.; Frija, G.

1986-01-01

To evaluate the paramagnetic properties of a new gadolinium chelate, Gd-DOTA, in vitro and in vivo MR imaging was performed with a 0.5-T supraconductive magnet. The in vitro study consisted in measuring the MR signal obtained with various concentrations of Gd-DOTA and Gd-DTPA in different solutions. Potentialization of the paramagnetic properties of both DOTA and DTPA can be achieved by deuterium, glycerol, and protein solutions. The in vivo study was performed in rabbits with various experimental lesions. Enhancement of anatomic details was obtained with both Gd-DOTA and Gd-DTPA. There was no significant difference between Gd-DOTA and Gd-DTPA, both for in vitro and in vivo experiments. Gd-DOTA appears to be a potential paramagnetic agent for MR imaging

Determination of Gd concentration profile in UO{sub 2}–Gd{sub 2}O{sub 3} fuel pellets

Energy Technology Data Exchange (ETDEWEB)

Tobia, D., E-mail: dina.tobia@cab.cnea.gov.ar [Laboratorio de Resonancias Magnéticas, Centro Atómico Bariloche – CNEA and CONICET, 8400 S.C. de Bariloche (Argentina); Winkler, E.L.; Milano, J.; Butera, A. [Laboratorio de Resonancias Magnéticas, Centro Atómico Bariloche – CNEA and CONICET, 8400 S.C. de Bariloche (Argentina); Kempf, R. [División Caracterización de Combustibles Avanzados, Gerencia Ciclo Combustible Nuclear, Centro Atómico Constituyentes – CNEA, 1650 San Martín, Pcia. de Buenos Aires (Argentina); Bianchi, L.; Kaufmann, F. [Departamento de Combustibles Avanzados, Gerencia Ciclo Combustible Nuclear, Centro Atómico Constituyentes – CNEA, 1650 San Martín, Pcia. de Buenos Aires (Argentina)

2014-08-01

A transversal mapping of the Gd concentration was measured in UO{sub 2}–Gd{sub 2}O{sub 3} nuclear fuel pellets by electron paramagnetic resonance spectroscopy (EPR). The quantification was made from the comparison with a Gd{sub 2}O{sub 3} reference sample. The nominal concentration in the pellets is UO{sub 2}: 7.5% Gd{sub 2}O{sub 3}. A concentration gradient was found, which indicates that the Gd{sub 2}O{sub 3} amount diminishes towards the edges of the pellets. The concentration varies from (9.3 ± 0.5)% in the center to (5.8 ± 0.3)% in one of the edges. The method was found to be particularly suitable for the precise mapping of the distribution of Gd{sup 3+} ions in the UO{sub 2} matrix.

Influence of the size of Gd211 starting powder on the critical current density of Gd-Ba-Cu-O bulk superconductor

International Nuclear Information System (INIS)

Nariki, S.; Seo, S.J.; Sakai, N.; Murakami, M.

2000-01-01

The relationship between the particle size of Gd211 powder in the precursor and the particle size of Gd211 inclusions in Gd-Ba-Cu-O bulk has been investigated. Gd211 starting powders with various diameters were prepared by the calcination of Gd 2 O 3 , BaO 2 and CuO powders at different temperatures between 800 and 1000 deg. C. The particle size of Gd211 in the melt-grown bulk was proportional to the particle size of the initial Gd211 powder. In conclusion, the employment of fine Gd211 powder led to a size reduction of 211 particles in the bulk, while largely enhancing the J c values in low magnetic fields. A large Gd-Ba-Cu-O/Ag bulk sample, 32 mm in diameter, could also be fabricated by the hot-seeding method. The maximum trapped field value revealed 1.5 T at 77 K. (author)

Gd(III)-nanodiamond conjugates for MRI contrast enhancement

Science.gov (United States)

Manus, Lisa M.; Mastarone, Daniel J.; Waters, Emily A.; Zhang, Xue-Qing; Schultz-Sikma, Elise A.; MacRenaris, Keith W.; Ho, Dean

2010-01-01

A Gd(III)-nanodiamond conjugate [Gd(III)-ND] was prepared and characterized, enabling detection of nanodiamonds by MR imaging. The Gd(III)-ND particles significantly reduced the T1 of water protons with a per-Gd(III) relaxivity of 58.82 ± 1.18 mM−1s−1 at 1.5 Tesla (60 MHz). This represents a tenfold increase compared to the monomer Gd(III) complex (r1 = 5.42 ± 0.20 mM−1s−1) and is among the highest per-Gd(III) relaxivities reported. PMID:20038088

Reversed phase partition chromatographic separation of Gd(III) on poly(Crown Ether) column

International Nuclear Information System (INIS)

Mahanwar, K.R.; Sabale, S.R.

2014-01-01

A simple method has been developed for the separation of Gd(III) in hippuric acid medium by using poly(dibenzo-18-crown-6) as stationary phase. The effect of hippuric acid concentration, different eluting agent, foreign ions etc was studied and the optimum conditions were established. Breakthrough capacity of poly(dibenzo-18-crown-6) for Gd(III) was found to be 0.572 ±0.01 mmolg -1 of crown polymer. The separation of Gd(III) from other elements in multicomponent mixtures has been achieved. The method was extended for determination of Gd(III) in real sample. The method is simple, rapid and selective with good reproducibility (approximately ± 2%). Crown ethers are widely used as complexing agent that can selectively capture metal cation in their cavity. This special feature shown by poly (dibenzo-18-crown-6) has been used in our laboratory for selective cation exchanger by column chromatography. No attempts were made for the separation of Gd(III) using hippuric acid media and column chromatography. The present communication describes a simple and sensitive method for the determination of Gd(III) using poly(dibenzo-18-crown-6) as stationary phase in hippuric acid medium. The proposed method affords an attractive feature as compared to the solvent extraction technique i.e. it is free from any organic diluents as an environmental concern

Synthesis, characterization and thermal behavior: Gd(NO3)3.6H2O to Gd2O3

International Nuclear Information System (INIS)

Ghonge, Darshana K.; Sheelvantra, Smita S.; Kalekar, Bhupesh B.; Raje, Naina

2015-01-01

Gadolinium oxide finds its application in nuclear as well as medical industry. It has been prepared from the thermal decomposition of gadolinium nitrate hexahydrate. Surface area of the synthesized compound was measured as 19 m 2 /g. EDS data shows only the presence of gadolinium and oxygen in the synthesized compound with the Gd to O ratio as calculated for Gd 2 O 3 , suggests the formation of pure Gd 2 O 3 . XRD analysis confirms the formation of pure cubic phase Gd 2 O 3 . In the absence of any report on the thermal behavior of GdNH, present studies have been carried out to understand the decomposition mechanism using simultaneous TG - DTA - EGA measurements

Synthesis and characterization of Gd-doped magnetite nanoparticles

International Nuclear Information System (INIS)

Zhang, Honghu; Malik, Vikash; Mallapragada, Surya; Akinc, Mufit

2017-01-01

Synthesis of magnetite nanoparticles has attracted increasing interest due to their importance in biomedical and technological applications. Tunable magnetic properties of magnetite nanoparticles to meet specific requirements will greatly expand the spectrum of applications. Tremendous efforts have been devoted to studying and controlling the size, shape and magnetic properties of magnetite nanoparticles. Here we investigate gadolinium (Gd) doping to influence the growth process as well as magnetic properties of magnetite nanocrystals via a simple co-precipitation method under mild conditions in aqueous media. Gd doping was found to affect the growth process leading to synthesis of controllable particle sizes under the conditions tested (0–10 at% Gd"3"+). Typically, undoped and 5 at% Gd-doped magnetite nanoparticles were found to have crystal sizes of about 18 and 44 nm, respectively, supported by X-ray diffraction and transmission electron microscopy. Our results showed that Gd-doped nanoparticles retained the magnetite crystal structure, with Gd"3"+ randomly incorporated in the crystal lattice, probably in the octahedral sites. The composition of 5 at% Gd-doped magnetite was Fe_(_3_−_x_)Gd_xO_4 (x=0.085±0.002), as determined by inductively coupled plasma mass spectrometry. 5 at% Gd-doped nanoparticles exhibited ferrimagnetic properties with small coercivity (~65 Oe) and slightly decreased magnetization at 260 K in contrast to the undoped, superparamagnetic magnetite nanoparticles. Templation by the bacterial biomineralization protein Mms6 did not appear to affect the growth of the Gd-doped magnetite particles synthesized by this method. - Highlights: • Gd-doped magnetite nanoparticles are synthesized via aqueous co-precipitation method under mild conditions. • Gd doping affects growth of magnetite nanoparticles leading to tunable particle size. • Gd-doped magnetite nanoparticles exhibit ferrimagnetic properties.

New perspective for GdNCT. Gd-DTPA reaches the nucleus of glioblastoma cells in culture and in vivo

International Nuclear Information System (INIS)

Stasio, G. de; Gilbert, B.; Frazer, B.H.

2000-01-01

We investigated the prospects of gadolinium as a neutron capture therapy agent by combining three independent techniques to study the uptake of Gd-DTPA in vitro, in cultured glioblastoma cells, and in vivo, in the glioblastoma tissue sections after injection of Gd-DTPA and tumor extraction. We show that gadolinium not only penetrates the plasma membrane of glioblastoma cells grown in culture, but we also observe a statistically significant higher concentration of Gd in the nucleus relative to the cytoplasm. For the in vivo experiments, Gd-DTPA was administered to 6 glioblastoma patients before neurosurgery. The extracted bioptic tissue was then analyzed with spectromictroscopy, showing Gd localized in the nuclei of glioblastoma cells in 5 patients out of the 6 analyzed. (author)

Tissue gadolinium deposition in hepatorenally impaired rats exposed to Gd-EOB-DTPA: evaluation with inductively coupled plasma mass spectrometry (ICP-MS).

Science.gov (United States)

Sato, Tomohiro; Tamada, Tsutomu; Watanabe, Shigeru; Nishimura, Hirotake; Kanki, Akihiko; Noda, Yasufumi; Higaki, Atsushi; Yamamoto, Akira; Ito, Katsuyoshi

2015-06-01

This study was undertaken to quantify tissue gadolinium (Gd) deposition in hepatorenally impaired rats exposed to gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA) by means of inductively coupled plasma mass spectrometry (ICP-MS) and to compare differences in Gd distribution among major organs as possible triggers for nephrogenic systemic fibrosis. Five hepatorenally impaired rats (5/6-nephrectomized, with carbon-tetrachloride-induced liver fibrosis) were injected with Gd-EOB-DTPA. Histological assessment was conducted and Gd content of the skin, liver, kidneys, lungs, heart, spleen, diaphragm, and femoral muscle was measured by inductively coupled plasma mass spectrometry (ICP-MS) at 7 days after last injection. In addition, five renally impaired rats were injected with Gd-EOB-DTPA and the degree of tissue Gd deposition was compared with that in the hepatorenally impaired rats. ICP-MS analysis revealed significantly higher Gd deposition in the kidneys, spleen, and liver (p = 0.009-0.047) in the hepatorenally impaired group (42.6 ± 20.1, 17.2 ± 6.1, 8.4 ± 3.2 μg/g, respectively) than in the renally impaired group (17.2 ± 7.7, 5.4 ± 2.1, 2.8 ± 0.7 μg/g, respectively); no significant difference was found for other organs. In the hepatorenally impaired group, Gd was predominantly deposited in the kidneys, followed by the spleen, liver, lungs, skin, heart, diaphragm, and femoral muscle. Histopathological investigation revealed hepatic fibrosis in the hepatorenally impaired group. Compared with renally impaired rats, tissue Gd deposition in hepatorenally impaired rats exposed to Gd-EOB-DTPA was significantly increased in the kidneys, spleen, and liver, probably due to the impairment of the dual excretion pathways of the urinary and biliary systems.

Comparison of two brain tumor-localizing MRI agent. GD-BOPTA and GD-DTPA. MRI and ICP study of rat brain tumor model

International Nuclear Information System (INIS)

Zhang, T.; Matsumura, A.; Yamamoto, T.; Yoshida, F.; Nose, T.

2000-01-01

In this study, we compared the behavior of Gd-BOPTA as a brain tumor selective contrast agent with Gd-DTPA in a common dose of 0.1 mmol/kg. We performed a MRI study using those two agent as contrast material, and we measured tissue Gd-concentrations by ICP-AES. As a result, Gd-BOPTA showed a better MRI enhancement in brain tumor. ICP showed significantly greater uptake of Gd-BOPTA in tumor samples, at all time course peaked at 5 minutes after administration, Gd being retained for a longer time in brain tumor till 2 hours, without rapid elimination as Gd-DTPA. We conclude that Gd-BOPTA is a new useful contrast material for MR imaging in brain tumor and an effective absorption agent for neutron capture therapy for further research. (author)

Structural and magnetic properties of Gd-doped ZnO

KAUST Repository

Bantounas, Ioannis

2014-01-01

We use density functional theory to investigate structural and magnetic properties of Gd doped ZnO, accounting for the impurity 4f states using the GGA + U method. (i) We calculate the binding energy of forming [Gd-Gd] dimers, [VO - GdZn] and [VZn - GdZn] complexes and find that while the formation of [VZn - GdZn] is favourable, [GdZn - GdZn] and [VO - GdZn] complexes are less likely to form. Next, (ii) we investigate the spacial arrangement of two (and three) GdZn impurities in a 3 × 3 × 2 supercell and find that the magnetic impurities are energetically favourable when occupying distant lattice sites. Finally, we study the nature of interactions between the magnetic impurities (iii) for Gd in nearest-neighbour and non-nearest-neighbour Zn sites, (iv) in the presence of Zn or O vacancies, and (v) with and without additional charge carriers. Our results show mainly paramagnetic behaviour. In a few cases, e.g. magnetic impurities occupying in-plane nearest-neighbour zinc sites with n-type carrier doping, weak ferromagnetic coupling is observed. This magnetic ordering is of the order of a few meV and can be easily destroyed by thermal fluctuations. We thus expect Gd:ZnO to show paramagnetic behaviour at temperatures approaching room temperature.

Investigation of Gd compounds using synchrotron radiation

International Nuclear Information System (INIS)

Tyszka, B.; Szade, J.; Burian, W.; Skorek, G.; Deniszczyk, J.; Sikora, M.; Zajac, D.; Kapusta, Cz.; Matteucci, M.; Bondino, F.; Zacchigna, M.; Zangrando, M.

2005-01-01

The electronic structure of ferromagnetic compound GdTiGe has been investigated using element sensitive methods-X-ray absorption spectroscopy (XAS), X-ray magnetic circular dichroism (XMCD) and resonant inelastic X-ray scattering (RIXS). Additionally, another ferromagnet GdTiSi has been studied using XMCD. XMCD revealed a strong dichroic signal at Gd L 2 and L 3 edges, which can be related to polarisation of Gd 5d band. XAS at Ti L 2,3 edges has exhibited a structure which appeared to be in general agreement with the LAPW calculations. RIXS spectra have shown some resonance features for photon energies close to Ti L 2 and Gd M 5 edges

Magnetism at the V/Gd interface

International Nuclear Information System (INIS)

Mouketo, L; M'Passi-Mabiala, B; Binggeli, N

2010-01-01

Recent experimental investigations into the magnetic properties of V/Gd bilayers have shown that vanadium, which is nonmagnetic in the bulk, can acquire a magnetic moment in such systems. We have performed ab initio pseudopotential calculations to examine the magnetic behavior of V(110)/Gd(0001) bilayers for V layers with thicknesses up to 4 monolayers (ML). We considered both abrupt and atomic intermixed V/Gd interfaces. In both cases, the magnetic moment of the V layer is found to align antiparallel to the moment of the Gd layer, consistent with the experimental observation. However, the magnitude of the V moment at the abrupt interface is considerably smaller than the moments reported experimentally. In the presence of atomic intermixing, instead, substantially larger V moments are found, closer to the experimentally reported moments. On the basis of the calculated atomic and spin resolved density of states, we discuss the possible mechanism responsible for the observed Gd-V antiferromagnetic coupling.

GdF Suez, the real energy champion

International Nuclear Information System (INIS)

Dupin, L.

2010-01-01

During summer 2010, France discovered that she owned a second energy giant, GdF Suez, ranked number two as a power producer just behind EdF, but world number one in the energy domain thanks to the taking over of International Power (UK) in 2010. Until now, GdF Suez and EdF were confronting with each other in a fair game, keeping their respective seizure on their historical monopolies, gas for GdF Suez and electricity for EdF. From now onward the two giants have started an open fight on all markets, with the exception of nuclear energy for which the French government continues to favour EdF. This paper recalls the main steps of the last 15 years of GdF Suez progress, from the Suez investment bank in 1995 to the merger with GdF in 2008 and the acquisition of International Power in 2010. Then it makes a comparative portrait of both GdF Suez and EdF energy groups with their respective advantages and, finally, it ends with an interview of G. Mestrallet, president of GdF Suez who explains the strategy of his group. (J.S.)

Experimental evaluation of contrast-enhanced high-reselution MR angiography in the rabbit. Gd-DTPA versus Gd-DTPA polylysin

International Nuclear Information System (INIS)

Vogl, T.J.; Hoffmann, Y.; Juergens, M.; Weinmann, H.J.; Muehler, A.; Yucel, S.; Felix, R.

1996-01-01

In ten anesthesized rabbits (average weight 4.3 kg) MR angiography was performed using a 1.5 TMR unit (Magnetom SP63; Siemens Erlangen) and a CP head coil. Arterial MRA (FISP 3D TONE, TR/TE=33/8, Flip 20 ) and venous MRA (FLASH 2D, TR/TE=37/10, Flip 60 ) was performed before and after administration of the paramagnetic contrast agents Gd-DTPA (n=5) or Gd-DTPA polylysine (n=5) at a doseage of 0.1 mmol/kg. In all studies the single selections and the MIP reconstructions were evaluated quantitatively by measuring and calculating signal intensity, percentage enhancement, signal-to-noise and contrast-to-noise ratios. All studies were assessed qualitatively for visualization and distinction of the arterial and venous vessel system by three independent observers before and after the administration of contrast agent. Results: Gd-DTPA-enhanced arterial FISP 3D tone led to a percentage enhancement of 30% for the kidneys, 12% for the superior mesenteric artery, 18% for the deep circumfluent iliac artery, and 7% for the internal iliac artery. In FLASH 2D sequences Gd-DTPA led to a good C/N only for venous abdominal vessels like the left renal vein (2.59) and internal iliac vein (1.66); the percentage enhancement of these structures was between 16 and 21%. Qualitative comparison also showed no significant improvement after injection of Gd-DTPA. In FISP 3D TONE sequences Gd-DTPA polylysine led to a strong percentlage enhancement of right and left kidney (21 and 40%) and deep circumfluent iliac artery (17%). Qualitative evaluation showed improved delineation and contrast of low-diameter vessels, while the soft tissue was only slightly enhanced and did not impair vessel visualization. Conclusion: CMRA using Gd-DTPA and Gd-DTPA polylysine significantly improved the delineation of abdominal vessels, with Gd-DTPA polylysine being superior. (orig.) [de

Magnetic upconverting fluorescent NaGdF4:Ln3+ and iron-oxide@NaGdF4:Ln3+ nanoparticles

Science.gov (United States)

Shrivastava, Navadeep; Rocha, Uéslen; Muraca, Diego; Jacinto, Carlos; Moreno, Sergio; Vargas, J. M.; Sharma, S. K.

2018-05-01

Microwave assisted solvothermal method has been employed to synthesize multifunctional upconverting β-NaGdF4:Ln3+ and magnetic-upconverting Fe3O4/γ-Fe2O3@NaGdF4:Ln3+ (Ln = Yb and Er) nanoparticles. The powder x-ray diffraction data confirms the hexagonal structure of NaGdF4:Ln3+ and high resolution transmission electron microscopy shows the formation of rod shaped NaGdF4:Ln3+ (˜ 20 nm) and ovoid shaped Fe3O4/γ-Fe2O3@NaGdF4:Ln3+ (˜ 15 nm) nanoparticles. The magnetic hysteresis at 300 K for β-NaGdF4:Ln3+ demonstrates paramagnetic features, whereas iron-oxide@β-NaGdF4:Ln3+ exhibits superparamagnetic behavior along with a linear component at large applied field due to paramagnetic NaGdF4 matrix. Both nanoparticle samples provide an excellent green emitting [(2H11/2, 4S3/2)→4I15/2 (˜ 540 nm)] upconversion luminescence emission under excitation at 980 nm. The energy migration between Yb and Er in NaGdF4 matrix has been explored from 300-800 nm. Intensity variation of blue, green and red lines and the observed luminescence quenching due to the presence of Fe3O4/γ-Fe2O3 in the composite has been proposed. These kinds of materials contain magnetic and luminescence characteristics into single nanoparticle open new possibility for bioimaging applications.

Multi-Ton Argon and Xenon

Energy Technology Data Exchange (ETDEWEB)

Alarcon, Ricardo; Balascuta, Septimiu; Alton, Drew; Aprile, Elena; Giboni, Karl-Ludwig; Haruyama, Tom; Lang, Rafael; Melgarejo, Antonio Jesus; Ni, Kaixuan; Plante, Guillaume; Choi, Bin [et al.

2009-01-01

There is a wide range of astronomical evidence that the visible stars and gas in all galaxies, including our own, are immersed in a much larger cloud of non-luminous matter, typically an order of magnitude greater in total mass. The existence of this ''dark matter'' is consistent with evidence from large-scale galaxy surveys and microwave background measurements, indicating that the majority of matter in the universe is non-baryonic. The nature of this non-baryonic component is still totally unknown, and the resolution of the ''dark matter puzzle'' is of fundamental importance to cosmology, astrophysics, and elementary particle physics. A leading explanation, motivated by supersymmetry theory, is the existence of as yet undiscovered Weakly Interacting Massive Particles (WIMPs), formed in the early universe and subsequently clustered in association with normal matter. WIMPs could, in principle, be detected in terrestrial experiments by their collisions with ordinary nuclei, giving observable low energy (< 100 keV) nuclear recoils. The predicted low collision rates require ultra-low background detectors with large (0.1-10 ton) target masses, located in deep underground sites to eliminate neutron background from cosmic ray muons. The establishment of the Deep Underground Science and Engineering Laboratory for large-scale experiments of this type would strengthen the current leadership of US researchers in this and other particle astrophysics areas. We propose to detect nuclear recoils by scintillation and ionization in ton-scale liquid noble gas targets, using techniques already proven in experiments at the 0.01-0.1 ton level. The experimental challenge is to identify these events in the presence of background events from gammas, neutrons, and alphas.

Lifetime measurement in 144Gd

International Nuclear Information System (INIS)

Jensen, H.J.; Gast, W.; Georgiev, A.; Jaeger, H.M.; Lieder, R.M.; Utzelmann, S.; Gierlik, M.; Morek, T.; Przestrzelska, K.; Rzaca-Urban, T.; Dewald, A.; Kuehn, R.; Meier, C.; Ender, C.; Haertlein, T.

1996-01-01

The lifetime measurements of excited states in 144 Gd were carried out using the Koeln RDM-plunger together with the 2 x 3 CLUSTER detector setup in Heidelberg. The nucleus was populated in the 100 Mo( 48 Ti,4n) 144 Gd reaction at a beam energy of 205 MeV giving a recoil velocity of v/c = 2.6 %. Three and higher fold γ-ray coincidences were measured at 12 target-stopper distances ranged from 0 to 400 μm. Both the dipole and quadrupole bands in 144 Gd have been observed. The analysis is in progress

Ferrimagnetic properties of Co/(Gd-Co) multilayers

International Nuclear Information System (INIS)

Svalov, A.V.; Fernandez, A.; Vas'kovskiy, V.O.; Tejedor, M.; Barandiaran, J.M.; Orue, I.; Kurlyandskaya, G.V.

2006-01-01

Co/(Gd-Co) multilayers have been prepared by rf-sputtering and investigated by means of Transverse Magnetooptic Kerr Effect (TMOKE), SQUID and VSM magnetometry. The composition of amorphous Gd 0.36 Co 0.64 layers was chosen so that their saturation magnetization was dominated by Gd moments in all the temperature range. Co and Gd-Co layers formed a macroscopic ferrimagnetically coupled system displaying a compensation temperature. Complete magnetic moment compensation was found at such point. An inversion of TMOKE hysteresis loops and a divergent behaviour of coercivity were also observed. By changing the layers thickness it has been possible to control the magnetic characteristics of the Co/(Gd-Co) structures, in particular the compensation takes place at different temperatures

An investigation of the Pd-Ag-Ru-Gd quaternary system phase diagram

International Nuclear Information System (INIS)

Zhang Kanghou; Xu Yun

2005-01-01

On the basis of the Ag-Pd-Gd, Ag-Ru-Gd and Pd-Ru-Gd ternary systems, the partial phase diagram of Pd-Ag-Ru-Gd (Gd 3 Gd and Ag 51 Gd 14 ; five two-phase regions: Pd(Ag) + (Ru), Pd(Ag) + Ag 51 Gd 14 (Ru) + Ag 51 Gd 14 , Pd(Ag) + Pd 3 Gd and (Ru) + Pd 3 Gd; three three-phase regions: Pd(Ag) + Pd 3 Gd + (Ru), Pd(Ag) + Ag 51 Gd 14 + (Ru) and (Ru) + Ag 51 Gd 14 + Pd 3 Gd; one four-phase region Pd(Ag) + (Ru) + Ag 51 Gd 14 + Pd 3 Gd. No new quaternary intermetallic phase has been found

Enhanced and uniform in-field performance in long (Gd, Y)-Ba-Cu-O tapes with zirconium doping fabricated by metal-organic chemical vapor deposition

International Nuclear Information System (INIS)

Selvamanickam, V; Guevara, A; Zhang, Y; Kesgin, I; Xie, Y; Carota, G; Chen, Y; Dackow, J; Zhang, Y; Zuev, Y; Cantoni, C; Goyal, A; Coulter, J; Civale, L

2010-01-01

The influence of Zr doping in (Gd, Y)-Ba-Cu-O ((Gd, Y)BCO) tapes made by metal-organic chemical vapor deposition has been studied with a specific objective of uniform and reproducible enhancement in in-field critical current (I c ) over long lengths. 50 m long tapes with 7.5 and 10 at.% Zr doping in 1 μm thick (Gd, Y)BCO films have been found to exhibit a sharply enhanced peak in I c in the orientation of field parallel to the c-axis and retain 28% of their self-field I c value at 77 K and 1 T. BaZrO 3 (BZO) nanocolumn density in the cross-sectional microstructure was found to increase with increasing Zr addition. The end segments of the 50 m long tapes were found to display nearly identical angular dependence of critical current at 77 K and 1 T, indicative of the uniformity in in-field performance over this length. A 610 m long tape was fabricated with 10% Zr doping and a 130 m segment showed a 3.2% uniformity in critical current measured every meter in the orientation of B || c-axis. A retention factor of 36% of the zero-field I c value measured at 0.52 T over the 130 m is consistent with that obtained in short samples.

Enhanced and uniform in-field performance in long (Gd, Y)-Ba-Cu-O tapes with zirconium doping fabricated by metal-organic chemical vapor deposition

Energy Technology Data Exchange (ETDEWEB)

Selvamanickam, V; Guevara, A; Zhang, Y; Kesgin, I [Texas Center for Superconductivity and Department of Mechanical Engineering, University of Houston, Houston, TX 77059 (United States); Xie, Y; Carota, G; Chen, Y; Dackow, J [SuperPower Incorporated, 450 Duane Avenue Schenectady, NY 12304 (United States); Zhang, Y; Zuev, Y; Cantoni, C; Goyal, A [Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Coulter, J; Civale, L [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)

2010-01-15

The influence of Zr doping in (Gd, Y)-Ba-Cu-O ((Gd, Y)BCO) tapes made by metal-organic chemical vapor deposition has been studied with a specific objective of uniform and reproducible enhancement in in-field critical current (I{sub c}) over long lengths. 50 m long tapes with 7.5 and 10 at.% Zr doping in 1 {mu}m thick (Gd, Y)BCO films have been found to exhibit a sharply enhanced peak in I{sub c} in the orientation of field parallel to the c-axis and retain 28% of their self-field I{sub c} value at 77 K and 1 T. BaZrO{sub 3} (BZO) nanocolumn density in the cross-sectional microstructure was found to increase with increasing Zr addition. The end segments of the 50 m long tapes were found to display nearly identical angular dependence of critical current at 77 K and 1 T, indicative of the uniformity in in-field performance over this length. A 610 m long tape was fabricated with 10% Zr doping and a 130 m segment showed a 3.2% uniformity in critical current measured every meter in the orientation of B || c-axis. A retention factor of 36% of the zero-field I{sub c} value measured at 0.52 T over the 130 m is consistent with that obtained in short samples.

Enhanced and Uniform in-Field Performance in Long (Gd,Y)-Ba-Cu-O Tapes with Zirconium Doping Fabricated by Metal Organic Chemical Vapor Deposition

Energy Technology Data Exchange (ETDEWEB)

Selvamanickam, V. [SuperPower Incorporated, Schenectady, New York; Guevara, A. [University of Houston, Houston; Zhang, Y. [University of Houston, Houston; Kesign, I. [University of Houston, Houston; Xie, Y. Y. [SuperPower Incorporated, Schenectady, New York; Carota, G. [SuperPower Incorporated, Schenectady, New York; Chen, Y. [SuperPower Incorporated, Schenectady, New York; Dackow, J. [SuperPower Incorporated, Schenectady, New York; Zhang, Yifei [ORNL; Zuev, Yuri L [ORNL; Cantoni, Claudia [ORNL; Goyal, Amit [ORNL; Coulter, J. [Los Alamos National Laboratory (LANL); Civale, L. [Los Alamos National Laboratory (LANL)

2010-01-01

The influence of Zr doping in (Gd, Y)-Ba-Cu-O ((Gd, Y)BCO) tapes made by metal-organic chemical vapor deposition has been studied with a specific objective of uniform and reproducible enhancement in in-field critical current (I{sub c}) over long lengths. 50 m long tapes with 7.5 and 10 at.% Zr doping in 1 {mu}m thick (Gd, Y)BCO films have been found to exhibit a sharply enhanced peak in I{sub c} in the orientation of field parallel to the c-axis and retain 28% of their self-field I{sub c} value at 77 K and 1 T. BaZrO{sub 3} (BZO) nanocolumn density in the cross-sectional microstructure was found to increase with increasing Zr addition. The end segments of the 50 m long tapes were found to display nearly identical angular dependence of critical current at 77 K and 1 T, indicative of the uniformity in in-field performance over this length. A 610 m long tape was fabricated with 10% Zr doping and a 130 m segment showed a 3.2% uniformity in critical current measured every meter in the orientation of {beta} {parallel} c-axis. A retention factor of 36% of the zero-field I{sub c} value measured at 0.52 T over the 130 m is consistent with that obtained in short samples.

Transportation system benefits of early deployment of a 75-ton multipurpose canister system

International Nuclear Information System (INIS)

Wankerl, M.W.; Schmid, S.P.

1995-01-01

In 1993 the US Civilian Radioactive Waste Management System (CRWMS) began developing two multipurpose canister (MPC) systems to provide a standardized method for interim storage and transportation of spent nuclear fuel (SNF) at commercial nuclear power plants. One is a 75-ton concept with an estimated payload of about 6 metric tons (t) of SNF, and the other is a 125-ton concept with an estimated payload of nearly 11 t of SNF. These payloads are two to three times the payloads of the largest currently certified US rail transport casks, the IF-300. Although is it recognized that a fully developed 125-ton MPC system is likely to provide a greater cost benefit, and radiation exposure benefit than the lower-capacity 75-ton MPC, the authors of this paper suggest that development and deployment of the 75-ton MPC prior to developing and deploying a 125-ton MPC is a desirable strategy. Reasons that support this are discussed in this paper

Anomalous Hall effect in Fe/Gd bilayers

KAUST Repository

Xu, W. J.; Zhang, Bei; Liu, Z. X.; Wang, Z.; Li, W.; Wu, Z. B.; Yu, R. H.; Zhang, Xixiang

2010-01-01

Non-monotonic dependence of anomalous Hall resistivity on temperature and magnetization, including a sign change, was observed in Fe/Gd bilayers. To understand the intriguing observations, we fabricated the Fe/Gd bilayers and single layers of Fe and Gd simultaneously. The temperature and field dependences of longitudinal resistivity, Hall resistivity and magnetization in these films have also been carefully measured. The analysis of these data reveals that these intriguing features are due to the opposite signs of Hall resistivity/or spin polarization and different Curie temperatures of Fe and Gd single-layer films. Copyright (C) EPLA, 2010

Anomalous Hall effect in Fe/Gd bilayers

KAUST Repository

Xu, W. J.

2010-04-01

Non-monotonic dependence of anomalous Hall resistivity on temperature and magnetization, including a sign change, was observed in Fe/Gd bilayers. To understand the intriguing observations, we fabricated the Fe/Gd bilayers and single layers of Fe and Gd simultaneously. The temperature and field dependences of longitudinal resistivity, Hall resistivity and magnetization in these films have also been carefully measured. The analysis of these data reveals that these intriguing features are due to the opposite signs of Hall resistivity/or spin polarization and different Curie temperatures of Fe and Gd single-layer films. Copyright (C) EPLA, 2010

Phase equilibrium of the Gd-Fe-Co system at 873 K

International Nuclear Information System (INIS)

Huang Jinli; Zhong Haichang; Xia Xiuwen; He Wei; Zhu Jinming; Deng Jianqiu; Zhuang Yinghong

2009-01-01

Phase equilibrium of the ternary Gd-Fe-Co system at 873 K was investigated by using X-ray diffraction technique, electron probe microanalysis, metallographic analysis and differential thermal analysis. The 873 K isothermal section of the phase diagram of the Gd-Fe-Co ternary system consists of 11 single-phase regions, 16 two-phase regions and 6 three-phase regions. Three pairs of corresponding compounds of Gd-Co and Gd-Fe, i.e., Gd 2 Co 17 and Gd 2 Fe 17 , GdCo 3 and GdFe 3 , GdCo 2 and GdFe 2 , form a continuous series of solid solution. The compound Gd 2 Co 7-x Fe x was found to have a broad solubility range from 0 to 31 at.% Fe. The maximum solubility of Co in Gd 6 Fe 23 is about 7 at.% Co. At 873 K, the maximum solubilities of Fe in Gd 3 Co and Gd 4 Co 3 are about 3 and 1 at.% Fe, respectively. No ternary compound was found in all ternary alloy samples

Effect of Gd substitution on structure and spectroscopic properties of (Lu,Gd)2O3:Eu ceramic scintillator

Science.gov (United States)

Cao, Maoqing; Hu, Zewang; Ivanov, Maxim; Dai, Jiawei; Li, Chaoyu; Kou, Huamin; Shi, Yun; Chen, Haohong; Xu, Jiayue; Pan, Yubai; Li, Jiang

2018-02-01

In this paper, (Lu1-xGdx)2O3:Eu (x = 0, 0.1, 0.3, 0.5, 0.7, 0.9) ceramics were consolidated by the solid-state reaction method combined with vacuum sintering without sintering aids. We investigated the effect of the varying contents of Gd2O3 on the structure and spectroscopic properties of (Lu1-xGdx)2O3:Eu ceramics. X-ray diffraction (XRD) patterns indicate that proper amount of Gd2O3 can incorporate well with Lu2O3 and form Lu2O3-Gd2O3 solid solution. However, excessive Gd3+-doping in Lu2O3 will lead to the cubic phase transforming into monoclinic even hexagonal phase. The Gd3+ substitution no more than 50% of Lu2O3 enhances the radioluminescence, and reduces the fluorescence lifetime. Transmittance, photoluminescence, and radiation damage of the (Lu1-xGdx)2O3:Eu scintillation ceramics were also studied.

Hyperfine structure in the Gd II spectrum and the nuclear electric quadrupole moment of 157Gd

International Nuclear Information System (INIS)

Clieves, H.P.; Steudel, A.

1979-01-01

The hyperfine structure of 157 Gd was investigated in 20 Gd II lines by means of a photoelectric recording Fabry-Perot interferometer with digital data processing. The hyperfine splitting factors, A and B, were obtained by computer fits to the observed line structures. Using a multiconfigurational set of wave functions in intermediate coupling derived by Wyart, mono-electronic parameters were deduced by a parametric treatment. The nuclear electric quadrupole moment of 157 Gd was evaluated from the quadrupole interaction of the 5d electron in 4f 7 5d6s, the 5d electron in 4f 7 5d6p, and the 6p electron in 4f 7 5d6p. The three values obtained for the quadrupole moment agree very well. The final result, corrected for Sternheimer shielding, is Q( 157 Gd) = 1.34(7) x 10 -24 cm 2 . (orig.) [de

Gd-doped GaN studied with element specificity: Very small polarization of Ga, paramagnetism of Gd and the formation of magnetic clusters

Energy Technology Data Exchange (ETDEWEB)

Ney, A., E-mail: ney@maglomat.d [Fachbereich Physik and Center for Nanointegration Duisburg-Essen (CeNIDE), Universitaet Duisburg-Essen, Lotharstr. 1, D-47057 Duisburg (Germany); Kammermeier, T.; Ollefs, K.; Ney, V.; Ye, S. [Fachbereich Physik and Center for Nanointegration Duisburg-Essen (CeNIDE), Universitaet Duisburg-Essen, Lotharstr. 1, D-47057 Duisburg (Germany); Dhar, S. [Fachbereich Physik and Center for Nanointegration Duisburg-Essen (CeNIDE), Universitaet Duisburg-Essen, Lotharstr. 1, D-47057 Duisburg (Germany); Paul-Drude-Institut fuer Festkoerperelektronik, Hausvogteiplatz 5-7, D-10117 Berlin (Germany); Ploog, K.H. [Paul-Drude-Institut fuer Festkoerperelektronik, Hausvogteiplatz 5-7, D-10117 Berlin (Germany); Roever, M.; Malindretos, J.; Rizzi, A. [IV. Physikalisches Institut and Virtual Institute of Spinelectronics (VISel), Georg August Universitaet Goettingen, D-37077 Goettingen (Germany); Wilhelm, F.; Rogalev, A. [European Synchrotron Radiation Facility (ESRF), 6 Rue Jules Horowitz, BP 220, 38043 Grenoble Cedex (France)

2010-05-15

Element specific X-ray linear dichroism (XLD), X-ray magnetic circular dichroism (XMCD) at the Ga K- and Ga and Gd L{sub 3}-edges and magnetic resonance measurements have been carried out on Gd:GaN grown by molecular beam epitaxy with different Gd concentrations. XMCD studies at the Ga K-edge reveal only a very weak magnetic polarization, which is too small to account for the colossal moments reported before by SQUID. In the dilute limit we can show by XLD that the majority of the Gd dopant atoms go to substitutional Ga sites. XMCD studies demonstrate that the Gd sublattice behaves paramagnetic which is in contrast to integral SQUID measurements. The absence of ferromagnetic order at room temperature is corroborated by magnetic resonance studies. First signatures of phase separation are visible. At higher Gd concentrations phase separation is found by XLD. In such samples ferromagnetic-like order is consistently found by SQUID, XMCD and magnetic resonance which is characteristic for a blocked superparamagnetic ensemble. In turn, phase separated ferromagnetic Gd/GdN clusters cannot account for magnetic order observed at and above 300 K by SQUID.

Test of E1-radiative strength function and level density models by 155 Gd (n,2γ) 156 Gd reaction

International Nuclear Information System (INIS)

Voinov, A.V.

1996-01-01

The information about the level density of 156 Gd nucleus and strength functions of γ transitions extracted from two γ-cascade spectra of the 155 Gd (n,2γ) 156 Gd reaction is analyzed. The method of statistical simulation of γ-cascade intensity is applied for calculation of the main parameters of experimental spectra. The method is used to extract the information on the E1-radiative strength function of γ transitions and level density in the 156 Gd nucleus. It is shown that at an excitation energy above 3 MeV the level density of 156 Gd nucleus must decrease in comparison with that calculated within the Fermi gas model. Its is concluded that possible explanation of the observed effect is connected with the influence of pairing correlations on the level density in nuclei

Localization and screening in GdNi alloy films

Energy Technology Data Exchange (ETDEWEB)

Wu, N.; Dowben, P.A. [Department of Physics and Astronomy, Nebraska Center for Materials and Nanoscience, University of Nebraska-Lincoln, Theodore Jorgenson Hall, 855 North 16th Street, Lincoln, Nebraska 68588-0299 (United States); LaGraffe, D. [Office of Proliferation Detection NA-22, National Nuclear Security Administration, US Department of Energy, 1000 Independence Avenue SW, Washington, DC 20585 (United States); Yakovkin, I.N. [National Academy of Science of Ukraine, Institute of Physics, Prospect Nauki 46, 03028 Kiev (Ukraine)

2011-05-15

Gd/Ni compounds with different Gd concentration have been investigated with constant initial state spectroscopy (CIS) of photoemission utilizing the light of synchrotron radiation. The photoemission cross-sections of Gd 5d and 4f states show a strong resonance in CIS spectra at the Gd 5p absorption edge. The screenings of Gd ions by Ni 3d conduction electrons results in a dramatic suppression of the 5p{sup 6}4f{sup 7}5d{sup 1}6s{sup 2} to 5p{sup 5}4f{sup 7}5d{sup 2}6s{sup 2} resonant enhancement of photoemission valence band intensities. This decrease in the super-Coster-Kronig photoemission resonant enhancement of the valence band can be related to the hybridized Gd 5d and Ni 3d bands near the Fermi level, consistent with performed first-principles calculations of local densities of states. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Investigation of nanocrystalline Gd films loaded with hydrogen

KAUST Repository

Hruška, Petr; Čí žek, Jakub; Dobroň, Patrik; Anwand, Wolfgang; Mü cklich, Arndt; Gemma, Ryota; Wagner, Stefan; Uchida, Helmut; Pundt, Astrid

2015-01-01

The present work reports on microstructure studies of hydrogen-loaded nanocrystalline Gd films prepared by cold cathode beam sputtering on sapphire (112¯0) substrates. The Gd films were electrochemically step-by-step charged with hydrogen and the structural development with increasing concentration of absorbed hydrogen was studied by transmission electron microscopy and in-situ   X-ray diffraction using synchrotron radiation. The relaxation of hydrogen-induced stresses was examined by acoustic emission measurements. In the low concentration range absorbed hydrogen occupies preferentially vacancy-like defects at GBs typical for nanocrystalline films. With increasing hydrogen concentration hydrogen starts to occupy interstitial sites. At the solid solution limit the grains gradually transform into the ββ-phase (GdH2). Finally at high hydrogen concentrations xH>2.0xH>2.0 H/Gd, the film structure becomes almost completely amorphous. Contrary to bulk Gd specimens, the formation of the γγ-phase (GdH3) was not observed in this work.

Radiation damage in CaF2: Gd

International Nuclear Information System (INIS)

Prado, L.

1979-01-01

Calcium fluoride crystals doped with Gd 3+ at four different concentrations were irradiated at room temperature. The damage produced by radiation and the primary and secondary effects as well were studied by optical spectroscopy. The increase in optical absorption (with loss of transparency) varied from sample as a function of concentration and dose. The coloration curves showed an evolution from two to three radiation damage steps when going from a pure to the most Gd 3+ concentrated sample. The obtained spectra were analysed at characteristic wave lenghts of electronic defects (photochromic centers, F and its aggregates) and of Gd 3+ and Gd 2+ defects. As a result of the radiation damage the valence change (Gd 3+ →Gd 2+ ) and its reversible character under thermal activation were directly observed. These effects were correlated with other observed effects such as the room temperature luminescence after the irradiation ceased. The non radiative F centers formation from the interaction of holes and photochromic centers was also observed and analysed. A thermal activation study of the several defects responsible for the different absorption bands was made. Values of activation energies were obtained as expected for the kind of defects involved in these processes [pt

Magnetic ordering of GdMn2

International Nuclear Information System (INIS)

Ouladdiaf, B.; Ritter, C.; Ballou, R.; Deportes, J.

1999-01-01

Complete text of publication follows. GdMn 2 crystallizes in the C15 cubic Laves phase structure. Within this structure Mn atoms lie at the vertices of regular tetrahedra stacked in the diamond arrangement connected by sharing vertices, leading to a strong geometric frustration. An antiferromagnetic magnetic order sets in below T N ∼ 105 K. It gives rise to a large magnetovolume effect (ΔV/V ∼ 1%). Thermal expansion data show two anomalies at 105 K and 35 K. The second anomaly was often interpreted as the ferromagnetic ordering of Gd sublattice. Moessbauer data indicate however, that Gd sublattice orders at T N ∼ 105 K as the Mn moments. Elastic neutron scattering measurements were performed using short wavelength neutron beam (λ = 0.5 A) on D9 at ILL. No magnetic contribution to the nuclear peaks was found excluding thereby any K = [0 0 0] component. However antiferromagnetic peaks indexed by a propagation vector [2/3 2/3 0] were observed leading to a non collinear magnetic arrangement of both Mn and Gd sublattices. The results are discussed by invoking the geometric frustration associated with the Mn atomic packing and the singlet state of the Gd ions. (author)

TonEBP modulates the protective effect of taurine in ischemia-induced cytotoxicity in cardiomyocytes

Science.gov (United States)

Yang, Y J; Han, Y Y; Chen, K; Zhang, Y; Liu, X; Li, S; Wang, K Q; Ge, J B; Liu, W; Zuo, J

2015-01-01

Taurine, which is found at high concentration in the heart, exerts several protective actions on myocardium. Physically, the high level of taurine in heart is maintained by a taurine transporter (TauT), the expression of which is suppressed under ischemic insult. Although taurine supplementation upregulates TauT expression, elevates the intracellular taurine content and ameliorates the ischemic injury of cardiomyocytes (CMs), little is known about the regulatory mechanisms of taurine governing TauT expression under ischemia. In this study, we describe the TonE (tonicity-responsive element)/TonEBP (TonE-binding protein) pathway involved in the taurine-regulated TauT expression in ischemic CMs. Taurine inhibited the ubiquitin-dependent proteasomal degradation of TonEBP, promoted the translocation of TonEBP into the nucleus, enhanced TauT promoter activity and finally upregulated TauT expression in CMs. In addition, we observed that TonEBP had an anti-apoptotic and anti-oxidative role in CMs under ischemia. Moreover, the protective effects of taurine on myocardial ischemia were TonEBP dependent. Collectively, our findings suggest that TonEBP is a core molecule in the protective mechanism of taurine in CMs under ischemic insult. PMID:26673669

Preclinical evaluation of multistep targeting of diasialoganglioside GD2 using a IgG-scFv bispecific antibody with high affinity for GD2 and DOTA metal complex

Science.gov (United States)

Cheal, Sarah M.; Xu, Hong; Guo, Hong-fen; Zanzonico, Pat B.; Larson, Steven M.; Cheung, Nai-Kong

2014-01-01

Bispecific antibodies (BsAb) have proven to be useful targeting vectors for pretargeted radioimmunotherapy (PRIT). We sought to overcome key PRIT limitations such as high renal radiation exposure and immunogenicity (e.g. of streptavidin-antibody fusions), to advance clinical translation of this PRIT strategy for diasialoganglioside GD2-positive (GD2(+)) tumors. For this purpose, a IgG-scFv BsAb was engineered using the sequences for the anti-GD2 humanized monoclonal antibody hu3F8 (1) and C825, a murine scFv antibody with high affinity for the chelator 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) complexed with beta-particle emitting radiometals such as 177Lu and 90Y (2, 3). A three-step regimen including hu3F8-C825, a dextran-based clearing agent, and p-aminobenzyl-DOTA radiolabeled with 177Lu (as 177Lu-DOTA-Bn; t1/2 = 6.71 days (d)) was optimized in immunocompromised mice carrying subcutaneous (s.c.) human GD2(+) neuroblastoma (NB) xenografts. Absorbed doses for tumor and normal tissues were ∼85 cGy/MBq and ≤3.7 cGy/MBq, respectively, with therapeutic indicies (TI) of 142 for blood and 23 for kidney. A therapy study (n = 5 per group; tumor volume: 240 ± 160 mm3) with three successive PRIT cycles (total 177Lu: ∼33 MBq; tumor dose ∼3400 cGy), revealed complete tumor response in 5/5 animals, with no recurrence up to 28 d post-treatment. Tumor ablation was confirmed histologically in 4/5 mice, and normal organs showed minimal overall toxicities. All non-treated mice required sacrifice within 12 d (>1.0 cm3 tumor volume). We conclude that this novel anti-GD2 PRIT approach has sufficient TI to successfully ablate s.c. GD2(+)–NB in mice while sparing kidney and bone marrow. PMID:24944121

Regional Feedstock Partnership Summary Report: Enabling the Billion-Ton Vision

Energy Technology Data Exchange (ETDEWEB)

Owens, Vance N. [South Dakota State Univ., Brookings, SD (United States). North Central Sun Grant Center; Karlen, Douglas L. [Dept. of Agriculture Agricultural Research Service, Ames, IA (United States). National Lab. for Agriculture and the Environment; Lacey, Jeffrey A. [Idaho National Lab. (INL), Idaho Falls, ID (United States). Process Science and Technology Division

2016-07-12

The U.S. Department of Energy (DOE) and the Sun Grant Initiative established the Regional Feedstock Partnership (referred to as the Partnership) to address information gaps associated with enabling the vision of a sustainable, reliable, billion-ton U.S. bioenergy industry by the year 2030 (i.e., the Billion-Ton Vision). Over the past 7 years (2008–2014), the Partnership has been successful at advancing the biomass feedstock production industry in the United States, with notable accomplishments. The Billion-Ton Study identifies the technical potential to expand domestic biomass production to offset up to 30% of U.S. petroleum consumption, while continuing to meet demands for food, feed, fiber, and export. This study verifies for the biofuels and chemical industries that a real and substantial resource base could justify the significant investment needed to develop robust conversion technologies and commercial-scale facilities. DOE and the Sun Grant Initiative established the Partnership to demonstrate and validate the underlying assumptions underpinning the Billion-Ton Vision to supply a sustainable and reliable source of lignocellulosic feedstock to a large-scale bioenergy industry. This report discusses the accomplishments of the Partnership, with references to accompanying scientific publications. These accomplishments include advances in sustainable feedstock production, feedstock yield, yield stability and stand persistence, energy crop commercialization readiness, information transfer, assessment of the economic impacts of achieving the Billion-Ton Vision, and the impact of feedstock species and environment conditions on feedstock quality characteristics.

Strongly coupled band in 140Gd

International Nuclear Information System (INIS)

Falla-Sotelo, F.; Oliveira, J.R.B.; Rao, M.N.

2005-01-01

Several high-K states are known to exist in the mass 130-140 region. For the N=74 even-even isotopes, Kπ = 8 - isomers, with lifetimes ranging from ns to ms, are known in 128 Xe, 130 Ba, 132 Ce, 134 Nd, 136 Sm, and 138 Gd[. In 140 Gd, we have observed for the first time a band also based on an Iπ = 8 - state. This could be the first case of a Kπ = 8 - state observed in an N=76 even-even isotope. The systematics of the Kπ = 8 - isomeric states in N=74 isotopes has been studied by A.M. Bruce et al. These states decay towards the K = 0 ground state band, and the transitions are K-forbidden. The 140 Gd case presents strong similarities but also some significant differences with relation to the N=74 isotopes. We propose the same configuration but with larger deformation in 140 Gd

Novel Gd nanoparticles enhance vascular contrast for high-resolution magnetic resonance imaging.

Directory of Open Access Journals (Sweden)

Tot Bui

2010-09-01

Full Text Available Gadolinium (Gd, with its 7 unpaired electrons in 4f orbitals that provide a very large magnetic moment, is proven to be among the best agents for contrast enhanced MRI. Unfortunately, the most potent MR contrast agent based on Gd requires relatively high doses of Gd. The Gd-chelated to diethylene-triamine-penta-acetic acid (DTPA, or other derivatives (at 0.1 mmole/kg recommended dose, distribute broadly into tissues and clear through the kidney. These contrast agents carry the risk of Nephrogenic Systemic Fibrosis (NSF, particularly in kidney impaired subjects. Thus, Gd contrast agents that produce higher resolution images using a much lower Gd dose could address both imaging sensitivity and Gd safety.To determine whether a biocompatible lipid nanoparticle with surface bound Gd can improve MRI contrast sensitivity, we constructed Gd-lipid nanoparticles (Gd-LNP containing lipid bound DTPA and Gd. The Gd-LNP were intravenously administered to rats and MR images collected. We found that Gd in Gd-LNP produced a greater than 33-fold higher longitudinal (T(1 relaxivity, r(1, constant than the current FDA approved Gd-chelated contrast agents. Intravenous administration of these Gd-LNP at only 3% of the recommended clinical Gd dose produced MRI signal-to-noise ratios of greater than 300 in all vasculatures. Unlike current Gd contrast agents, these Gd-LNP stably retained Gd in normal vasculature, and are eliminated predominately through the biliary, instead of the renal system. Gd-LNP did not appear to accumulate in the liver or kidney, and was eliminated completely within 24 hrs.The novel Gd-nanoparticles provide high quality contrast enhanced vascular MRI at 97% reduced dose of Gd and do not rely on renal clearance. This new agent is likely to be suitable for patients exhibiting varying degrees of renal impairment. The simple and adaptive nanoparticle design could accommodate ligand or receptor coating for drug delivery optimization and in vivo drug

GD 358 - the demise of rotational splitting?

International Nuclear Information System (INIS)

Hill, J.A.

1987-01-01

Observations of GD 358 were obtained at the McDonald Observatory in 1982 and 1985 in order to determine its periods, stability, and rates of period change. The period structure could not be resolved, and the results indicate that GD 358 does not fit the rotational splitting model. It is suggested that if the changes in the amplitude spectra of GD 358 are due to beating of stable modes, then the number of modes must be large. 7 references

A new entry in GdNCT. The nanodosimetry

International Nuclear Information System (INIS)

Cerullo, Nicola; Bufalino, Domenico; Esposito, Juan

2006-01-01

The GdNCT is a recently proposed therapy, mainly based on the action of Auger and IC electrons, generated by 157 Gd after neutron activation. The energy carried out by these electrons is limited to about 1% of total energy of the reaction, but due to high electron LET, if the emitter is bound to DNA, their action is very effective. Some Gd compounds have the property to be bound to DNA. Therefore the evaluation of the DNA damage caused by the Gd-emitted electrons is a key issue. The DNA damage is due to almost double strand breaks (DSB) in the DNA double helix chain. The dimensions concerned are of the order of 2 to 3 nm. Therefore, in the study of GdNCT, besides macro and micro, we must use the new 'nanodosimetry', based on particle interactions in the nanometric sites. A general review on GdNCT state of the art and on the nanometric Monte Carlo computing techniques, applied to a DNA model, is here presented. (author)

Criticality safety review of 2 1/2-, 10-, and 14-ton UF6 cylinders

International Nuclear Information System (INIS)

Broadhead, B.L.

1991-10-01

Currently, UF 6 cylinders designed to contain 2 1/2 tons of UF 6 are classified as Fissile Class 2 packages with a transport index (TI) of 5 for the purpose of transportation. The 10-ton UF 6 cylinders are classified as Fissile Class 1 with no TI assigned for transportation. The 14-ton cylinders, although not certified for transport with enrichments greater than 1 wt % because they have no approved overpack, can be used in on-site operations for enrichments greater than 1 wt %. The maximum 235 U enrichments for these cylinders are 5.0 wt % for the 2 1/2-ton cylinder and 4.5 wt % for the 10- and 14-ton cylinders. This work reviews the suitability for reclassification of the 2 1/2-ton UF 6 packages as Fissile Class 1 with a maximum 235 U enrichment of 5 wt %. Additionally, the 10- and 14-ton cylinders are reviewed to address a change in maximum 235 U enrichment from 4.5 to 5 wt %. Based on this evaluation, the 2 1/2-ton UF 6 cylinders meet the 10 CFR.71 criteria for Fissile Class 1 packages, and no TI is needed for criticality safety purposes; however, a TI may be required based on radiation from the packages. Similarly, the 10- and 14-ton UF 6 packages appear acceptable for a maximum enrichment rating change to 5 wt % 235 U. 11 refs., 13 figs., 7 tabs

305 Building 2 ton bridge crane and monorail assembly analysis

International Nuclear Information System (INIS)

Axup, M.D.

1995-12-01

The analyses in the appendix of this document evaluate the integrity of the existing bridge crane structure, as depicted on drawing H-3-34292, for a bridge crane and monorail assembly with a load rating of 2 tons. This bridge crane and monorail assembly is a modification of a 1 1/2 ton rated manipulator bridge crane which originally existed in the 305 building

Hyperfine fields at some 4d, 5d and 4f impurities in ferromagnetic GdZn and GdCd

International Nuclear Information System (INIS)

Kasamatsu, Y.; Kojima, K.; Hihara, T.

1995-01-01

Hyperfine (hf) fields at 4d (Y, Nb, Rh, Pd), 5d (Lu, Ta, Ir) and 4f (La, Nd, Sm, Eu) impurities in ferromagnetic GdZn and GdCd have been measured by NMR at 4.2 K. The local moment contributions to the hf field suggest that the impurity moments at the beginning and end of the d series are parallel and antiparallel to Gd moments, respectively. The hf results for 4f impurities are also discussed. ((orig.))

Synthesis, crystal structure, and physical properties of the Gd{sub 3}BiO{sub 3} and Gd{sub 8}Bi{sub 3}O{sub 8} phases

Energy Technology Data Exchange (ETDEWEB)

Forbes, Scott; Yuan, Fang [Department of Chemistry and Chemical Biology, McMaster University, 1280 Main Street West, Hamilton, Ontario, Canada L8S 4M1 (Canada); Kosuda, Kosuke; Kolodiazhnyi, Taras [Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan); Mozharivskyj, Yurij, E-mail: mozhar@mcmaster.ca [Department of Chemistry and Chemical Biology, McMaster University, 1280 Main Street West, Hamilton, Ontario, Canada L8S 4M1 (Canada)

2016-01-15

The second and third known rare-earth bismuthide oxides, Gd{sub 3}BiO{sub 3} and Gd{sub 8}Bi{sub 3}O{sub 8}, have been discovered via high temperature reactions at 1300 °C. Like its Gd–Sb–O counterparts, the Gd{sub 3}BiO{sub 3} and Gd{sub 8}Bi{sub 3}O{sub 8} phases crystallize in the monoclinic C2/m space group, with the latter containing disordered Bi atoms along the b direction of the unit cell. Unlike the RE{sub 8}Sb{sub 3}O{sub 8} series, the formation of the Gd{sub 3}BiO{sub 3} phase does not necessarily precede the formation of Gd{sub 8}Bi{sub 3}O{sub 8}, which is likely due to the difficulty of accommodating bismuth in the RE–O framework due to its larger size. Physical property measurements performed on a pure Gd{sub 8}Bi{sub 3}O{sub 8} sample reveal semiconducting behavior. Although electronic structure calculations predict metallic behavior due to an unbalanced electron count, the semiconducting behavior originates from the Anderson localization of the Bi p states near the Fermi level as a result of atomic disorder. - Graphical abstract: Reaction of GdBi and Gd{sub 2}O{sub 3} at high temperatures yields Gd–Bi–O phases. - Highlights: • Gd{sub 3}BiO{sub 3} and Gd{sub 8}Bi{sub 3}O{sub 8}, the second and third rare-earth bismuthide oxides, have been discovered. • Gd{sub 3}BiO{sub 3} and Gd{sub 8}Bi{sub 3}O{sub 8} are isostructural with RE{sub 3}SbO{sub 3} and RE{sub 8}Sb{sub 3}O{sub 8}. • Gd{sub 8}Bi{sub 3}O{sub 8} displays semiconducting behavior despite an unbalanced electron count. • Anderson localization of Bi p states results in semiconducting behavior in Gd{sub 8}Bi{sub 3}O{sub 8}.

Hydrothermally synthesized PEGylated calcium phosphate nanoparticles incorporating Gd-DTPA for contrast enhanced MRI diagnosis of solid tumors.

Science.gov (United States)

Mi, Peng; Kokuryo, Daisuke; Cabral, Horacio; Kumagai, Michiaki; Nomoto, Takahiro; Aoki, Ichio; Terada, Yasuko; Kishimura, Akihiro; Nishiyama, Nobuhiro; Kataoka, Kazunori

2014-01-28

Organic-inorganic hybrid nanoparticles with calcium phosphate (CaP) core and PEGylated shell were developed to incorporate magnetic resonance imaging (MRI) contrast agent diethylenetriaminepentaacetic acid gadolinium (III) (Gd-DTPA) for noninvasive diagnosis of solid tumors. A two-step preparation method was applied to elaborate hybrid nanoparticles with a z-average hydrodynamic diameter about 80nm, neutral surface ξ-potential and high colloidal stability in physiological environments by self-assembly of poly(ethylene glycol)-b-poly(aspartic acid) block copolymer, Gd-DTPA, and CaP in aqueous solution, followed with hydrothermal treatment. Incorporation into the hybrid nanoparticles allowed Gd-DTPA to show significant enhanced retention ratio in blood circulation, leading to high accumulation in tumor positions due to enhanced permeability and retention (EPR) effect. Moreover, Gd-DTPA revealed above 6 times increase of relaxivity in the nanoparticle system compared to free form, and eventually, selective and elevated contrast enhancements in the tumor positions were observed. These results indicate the high potential of Gd-DTPA-loaded PEGylated CaP nanoparticles as a novel contrast agent for noninvasive cancer diagnosis. Copyright © 2013 Elsevier B.V. All rights reserved.

Experimental and theoretical study of pure and doped crystals: Gd2O2S, Gd2O2S:Eu3+ and Gd2O2S:Tb3+

Science.gov (United States)

Wang, Fei; Chen, Xiumin; Liu, Dachun; Yang, Bin; Dai, Yongnian

2012-08-01

Quantum chemistry and experimental method were used to study on pure and doped Gd2O2S crystals in this paper. The band structure and DOS diagrams of pure and doped Gd2O2S crystals which calculated by using DFT (Density Functional Theory) method were illustrated to explain the luminescent properties of impurities in crystals. The calculations of the crystal structure were finished by using the program of CASTEP (Cambridge Sequential Total Energy Package). The samples showed the characteristic emissions of Tb3+ ions with 5D4-7FJ transitions and Eu3+ ions with 5D0-7FJ transitions which emit pure green luminescence and red luminescence respectively. The experimental excitation spectra of Tb3+ and Eu3+ doped Gd2O2S are in agreement of the DOS diagrams over the explored energy range, which has allowed a better understanding of different luminescence mechanisms of Tb3+ and Eu3+ in Gd2O2S crystals.

Synthesis, structural characterization, luminescent properties and theoretical study of three novel lanthanide metal-organic frameworks of Ho(III), Gd(III) and Eu(III) with 2,5-thiophenedicarboxylate anion

Energy Technology Data Exchange (ETDEWEB)

Marques, Lippy F. [Instituto de Química, Universidade do Estado do Rio de Janeiro, Rio de Janeiro 20550-013 (Brazil); Correa, Charlane C. [Departamento de Química-ICE, Universidade Federal de Juiz de Fora, Juiz de Fora-MG, 36036-330 (Brazil); Ribeiro, Sidney J.L.; Santos, Molíria V. dos [Institute of Chemistry, São Paulo State University − UNESP, CP 355 Araraquara-SP 14801-970 Brazil (Brazil); Dutra, José Diogo L.; Freire, Ricardo O. [Pople Computational Chemistry Laboratory, Departamento de Química, Universidade Federal de Sergipe, São Cristóvão-SE 49100-000 (Brazil); Machado, Flávia C., E-mail: flavia.machado@ufjf.edu.br [Departamento de Química-ICE, Universidade Federal de Juiz de Fora, Juiz de Fora-MG, 36036-330 (Brazil)

2015-07-15

In this paper, the synthesis of three new metal-organic frameworks of lanthanides (LnMOFs) ([Ln{sub 2}(2,5-tdc){sub 3}(dmso){sub 2}]·H{sub 2}O){sub n} (Ln=Ho (1); Gd (2); Eu (3); 2,5-tdc=2,5-thiophenedicarboxylate anion; dmso=dimethylsulfoxide), and their complete characterization, including single crystal X-ray diffraction, FTIR spectroscopy and thermogravimetric analysis are reported. In especial, photophysical properties of Eu(III) complex have been studied in detail via both theoretical and experimental approaches. Crystal structure of (1) reveals that each lanthanide ion is seven-coordinated by oxygen atoms in an overall distorted capped trigonal – prismatic geometry. The 2,5-tdc{sup 2−} ligands connect four Ln(III) centers, adopting (κ{sup 1}–κ{sup 1})–(κ{sup 1}–κ{sup 1})–μ{sub 4} coordination mode, generating an 8-connected uninodal 3D network. In addition, theoretical studies for Eu(III) complex were performed using the Sparkle model for lanthanide complexes. - Graphical abstract: Three new metal-organic frameworks of lanthanides (LnMOFs) ([Ln{sub 2}(2,5-tdc){sub 3}(dmso){sub 2}]·H{sub 2}O){sub n} (Ln=Ho (1); Gd (2); Eu (3); 2,5-tdc=2,5-thiophenedicarboxylate anion; dmso=dimethylsulfoxide), were synthesized and their complete characterization, including single crystal X-ray diffraction, FTIR spectroscopy and thermogravimetric analysis are reported. In especial, photophysical properties of Eu(III) complex have been studied in detail via both theoretical and experimental approaches. - Highlights: • Three new LnMOFs were synthesized and fully characterized. • Ho{sup 3+}, Gd{sup 3+} and Eu{sup 3+} complexes photoluminescence properties were investigated. • Theoretical approaches for Eu{sup 3+} complex luminescence has been performed. • An energy level diagram is used to establish the ligand-to-metal energy transfer. • These metal−organic frameworks can act as light conversion molecular devices.

In vivo evidence of TonB shuttling between the cytoplasmic and outer membrane in Escherichia coli.

Science.gov (United States)

Larsen, Ray A; Letain, Tracy E; Postle, Kathleen

2003-07-01

Gram-negative bacteria are able to convert potential energy inherent in the proton gradient of the cytoplasmic membrane into active nutrient transport across the outer membrane. The transduction of energy is mediated by TonB protein. Previous studies suggest a model in which TonB makes sequential and cyclic contact with proteins in each membrane, a process called shuttling. A key feature of shuttling is that the amino-terminal signal anchor must quit its association with the cytoplasmic membrane, and TonB becomes associated solely with the outer membrane. However, the initial studies did not exclude the possibility that TonB was artifactually pulled from the cytoplasmic membrane by the fractionation process. To resolve this ambiguity, we devised a method to test whether the extreme TonB amino-terminus, located in the cytoplasm, ever became accessible to the cys-specific, cytoplasmic membrane-impermeant molecule, Oregon Green(R) 488 maleimide (OGM) in vivo. A full-length TonB and a truncated TonB were modified to carry a sole cysteine at position 3. Both full-length TonB and truncated TonB (consisting of the amino-terminal two-thirds) achieved identical conformations in the cytoplasmic membrane, as determined by their abilities to cross-link to the cytoplasmic membrane protein ExbB and their abilities to respond conformationally to the presence or absence of proton motive force. Full-length TonB could be amino-terminally labelled in vivo, suggesting that it was periplasmically exposed. In contrast, truncated TonB, which did not associate with the outer membrane, was not specifically labelled in vivo. The truncated TonB also acted as a control for leakage of OGM across the cytoplasmic membrane. Further, the extent of labelling for full-length TonB correlated roughly with the proportion of TonB found at the outer membrane. These findings suggest that TonB does indeed disengage from the cytoplasmic membrane during energy transduction and shuttle to the outer membrane.

Chemical bonding and magnetic properties of gadolinium (Gd) substituted cobalt ferrite

International Nuclear Information System (INIS)

Puli, Venkata Sreenivas; Adireddy, Shiva; Ramana, C.V.

2015-01-01

Graphical abstract: Room temperature Raman spectra of CoFe 2−x Gd x O 4 (CFGO, x = 0.0–0.3) compounds as a function of wavenumber (cm −1 ). - Highlights: • Gd substituted ferrites were synthesized under controlled concentration. • Gd ion induced lattice dynamical changes are significant. • Enhanced magnetization is observed upon Gd-incorporation in cobalt ferrite. • A correlation between lattice dynamics and magnetic properties is established. - Abstract: Polycrystalline gadolinium (Gd) substituted cobalt ferrites (CoFe 2−x Gd x O 4 ; x = 0–0.3, referred to CFGO) ceramics have been synthesized by solid state reaction method. Chemical bonding, crystal structure and magnetic properties of CFGO compounds have been evaluated as a function of Gd-content. X-ray diffraction (XRD) and Raman spectroscopic analyses confirmed the formation of inverse spinel cubic structure. However, a secondary ortho-ferrite phase (GdFeO 3 ) nucleates for higher values of Gd-content. A considerable increase in the saturation magnetization has been observed upon the initial substitution of Gd (x = 0.1). The saturation magnetization drastically decreases at higher Gd content (x ⩾ 0.3). No contribution from ortho-ferrite GdFeO 3 phase is noted to the magnetic properties. The increase in the magnetic saturation magnetization is attributed to the higher magnetic moment of Gd 3+ (4f 7 ) residing in octahedral sites is higher when compared to that of Fe 3+ (3d 5 ) and as well due to the migration of Co 2+ (3d 7 ) ions from the octahedral to the tetrahedral sites with a magnetic moment aligned anti-parallel to those of rare earth (RE 3+ ) ions in the spinel lattice. Increase in coercivity with increase in Gd 3+ is content is attributed to magnetic anisotropy in the ceramics

Ferromagnetism in Gd doped ZnO nanowires: A first principles study

KAUST Repository

Aravindh, S. Assa

2014-12-19

In several experimental studies, room temperature ferromagnetism in Gd-doped ZnO nanostructures has been achieved. However, the mechanism and the origin of the ferromagnetism remain controversial. We investigate the structural, magnetic, and electronic properties of Zn 48O48 nanowires doped with Gd, using density functional theory. Our findings indicate that substitutionally incorporated Gd atoms prefer occupying the surface Zn sites. Moreover, the formation energy increases with the distance between Gd atoms, signifying that no Gd-Gd segregation occurs in the nanowires within the concentration limit of ≤2%. Gd induces ferromagnetism in ZnO nanowires with magnetic coupling energy up to 21 meV in the neutral state, which increases with additional electron and O vacancy, revealing the role of carriers in magnetic exchange. The potential for achieving room temperature ferromagnetism and high TC in ZnO:Gd nanowires is evident from the large ferromagnetic coupling energy (200 meV) obtained with the O vacancy. Density of states shows that Fermi level overlaps with Gd f states with the introduction of O vacancy, indicating the possibility of s-f coupling. These results will assist in understanding experimental findings in Gd-doped ZnO nanowires.

Ferromagnetism in Gd doped ZnO nanowires: A first principles study

KAUST Repository

Aravindh, S. Assa; Schwingenschlö gl, Udo; Roqan, Iman S.

2014-01-01

In several experimental studies, room temperature ferromagnetism in Gd-doped ZnO nanostructures has been achieved. However, the mechanism and the origin of the ferromagnetism remain controversial. We investigate the structural, magnetic, and electronic properties of Zn 48O48 nanowires doped with Gd, using density functional theory. Our findings indicate that substitutionally incorporated Gd atoms prefer occupying the surface Zn sites. Moreover, the formation energy increases with the distance between Gd atoms, signifying that no Gd-Gd segregation occurs in the nanowires within the concentration limit of ≤2%. Gd induces ferromagnetism in ZnO nanowires with magnetic coupling energy up to 21 meV in the neutral state, which increases with additional electron and O vacancy, revealing the role of carriers in magnetic exchange. The potential for achieving room temperature ferromagnetism and high TC in ZnO:Gd nanowires is evident from the large ferromagnetic coupling energy (200 meV) obtained with the O vacancy. Density of states shows that Fermi level overlaps with Gd f states with the introduction of O vacancy, indicating the possibility of s-f coupling. These results will assist in understanding experimental findings in Gd-doped ZnO nanowires.

Faraday effect in Gd3Al5O12 and Gd3Ga5O12 rare earth garnets

International Nuclear Information System (INIS)

Valiev, U.V.; Klochkov, A.A.; Popov, A.I.; Sokolov, Y.B.

1989-01-01

The dispersion of the Faraday rotation of the garnets Gd 3 Ga 5 O 12 and Gd 3 Al 5 O 12 in the 440--700-nm region in the 85--295-K temperature interval and the spectral dependence of the Faraday effect in the garnets Y 3 Ga 5 O 12 and Y 3 Al 5 O 12 for wavelengths from 250 to 700 nm are investigated. The contributions to the Faraday rotation caused by the Gd 3+ ions and the diamagnetic lattice of the garnets are separated

Obtaining strong ferromagnetism in diluted Gd-doped ZnO thin films through controlled Gd-defect complexes

KAUST Repository

Roqan, Iman S.

2015-02-21

We demonstrate the fabrication of reproducible long-range ferromagnetism (FM) in highly crystalline GdxZn1-xO thin films by controlling the defects. Films are grown on lattice-matched substrates by pulsed laser deposition at low oxygen pressures (≤25 mTorr) and low Gd concentrations (x ≤ 0.009). These films feature strong FM (10 μB per Gd atom) at room temperature. While films deposited at higher oxygen pressure do not exhibit FM, FM is recovered by post-annealing these films under vacuum. These findings reveal the contribution of oxygen deficiency defects to the long-range FM. We demonstrate the possible FM mechanisms, which are confirmed by density functional theory study, and show that Gd dopants are essential for establishing FM that is induced by intrinsic defects in these films.

Obtaining strong ferromagnetism in diluted Gd-doped ZnO thin films through controlled Gd-defect complexes

KAUST Repository

Roqan, Iman S.; Venkatesh, S.; Zhang, Z.; Hussain, S.; Bantounas, Ioannis; Franklin, J. B.; Flemban, Tahani H.; Zou, B.; Lee, J.-S.; Schwingenschlö gl, Udo; Petrov, P. K.; Ryan, M. P.; Alford, N. M.

2015-01-01

We demonstrate the fabrication of reproducible long-range ferromagnetism (FM) in highly crystalline GdxZn1-xO thin films by controlling the defects. Films are grown on lattice-matched substrates by pulsed laser deposition at low oxygen pressures (≤25 mTorr) and low Gd concentrations (x ≤ 0.009). These films feature strong FM (10 μB per Gd atom) at room temperature. While films deposited at higher oxygen pressure do not exhibit FM, FM is recovered by post-annealing these films under vacuum. These findings reveal the contribution of oxygen deficiency defects to the long-range FM. We demonstrate the possible FM mechanisms, which are confirmed by density functional theory study, and show that Gd dopants are essential for establishing FM that is induced by intrinsic defects in these films.

Electronic Structure of GdCuGe Intermetallic Compound

Science.gov (United States)

Lukoyanov, A. V.; Knyazev, Yu. V.; Kuz'min, Yu. I.

2018-04-01

The electronic structure of GdCuGe intermetallic compound has been studied. Spin-polarized energy spectrum calculations have been performed by the band method with allowance for strong electron correlations in the 4 f-shell of gadolinium ions. Antiferromagnetic ordering of GdCuGe at low temperatures has been obtained in a theoretical calculation, with the value of the effective magnetic moment of gadolinium ions reproduced in fair agreement with experimental data. The electronic density of states has been analyzed. An optical conductivity spectrum has been calculated for GdCuGe; it reveals specific features that are analogous to the ones discovered previously in the GdCuSi compound with a similar hexagonal structure.

2016 Billion-Ton Report: Advancing Domestic Resources for a Thriving Bioeconomy

Energy Technology Data Exchange (ETDEWEB)

None

2016-07-06

This product builds on previous efforts, namely the 2005 Billion-Ton Study (BTS) and the 2011 U.S. Billion-Ton Update (BT2).With each report, greater perspective is gained on the potential of biomass resources to contribute to a national energy strategy. Similarly, each successive report introduces new questions regarding commercialization challenges. BTS quantified the broad biophysical potential of biomass nationally, and BT2 elucidated the potential economic availability of these resources. These reports clearly established the potential availability of up to one billion tons of biomass resources nationally. However, many questions remain, including but not limited to crop yields, climate change impacts, logistical operations, and systems integration across production, harvest, and conversion. The present report aims to address many of these questions through empirically modeled energy crop yields, scenario analysis of resources delivered to biorefineries, and the addition of new feedstocks. Volume 2 of the 2016 Billion-Ton Report is expected to be released by the end of 2016. It seeks to evaluate environmental sustainability indicators of select scenarios from volume 1 and potential climate change impacts on future supplies.

The magnetic anisotropy of Gd-Y alloys

Science.gov (United States)

Phu Thuy, Nguyen; Verdonk, H. J.; Menovsky, A.; Franse, J. J. M.; Gersdorf, R.

1983-02-01

Magnetic torque curves on single crystals of Gd 1- xY x ( x ⩽ 0.1) show a reduction of the anomalous contribution that was observed in pure Gd, with increasing Y-content. Several explanations of this phenomenon are indicated in this paper.

Ferromagnetism in Gd doped ZnO nanowires: A first principles study

Energy Technology Data Exchange (ETDEWEB)

Aravindh, S. Assa; Schwingenschloegl, Udo, E-mail: udo.schwingenschloegl@kaust.edu.sa, E-mail: iman.roqan@kaust.edu.sa; Roqan, Iman S., E-mail: udo.schwingenschloegl@kaust.edu.sa, E-mail: iman.roqan@kaust.edu.sa [Physical Sciences and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900 (Saudi Arabia)

2014-12-21

In several experimental studies, room temperature ferromagnetism in Gd-doped ZnO nanostructures has been achieved. However, the mechanism and the origin of the ferromagnetism remain controversial. We investigate the structural, magnetic, and electronic properties of Zn{sub 48}O{sub 48} nanowires doped with Gd, using density functional theory. Our findings indicate that substitutionally incorporated Gd atoms prefer occupying the surface Zn sites. Moreover, the formation energy increases with the distance between Gd atoms, signifying that no Gd-Gd segregation occurs in the nanowires within the concentration limit of ≤2%. Gd induces ferromagnetism in ZnO nanowires with magnetic coupling energy up to 21 meV in the neutral state, which increases with additional electron and O vacancy, revealing the role of carriers in magnetic exchange. The potential for achieving room temperature ferromagnetism and high T{sub C} in ZnO:Gd nanowires is evident from the large ferromagnetic coupling energy (200 meV) obtained with the O vacancy. Density of states shows that Fermi level overlaps with Gd f states with the introduction of O vacancy, indicating the possibility of s-f coupling. These results will assist in understanding experimental findings in Gd-doped ZnO nanowires.

Effect of rare-earth composition on microstructure and pinning properties of Zr-doped (Gd,Y)Ba2Cu3Ox superconducting tapes

International Nuclear Information System (INIS)

Selvamanickam, V; Zhang, Y; Guevara, A; Shi, T; Yao, Y; Majkic, G; Galtsyan, E; Chen, Y; Lei, C; Miller, D J

2012-01-01

The effect of changing Gd + Y content from 1.2 to 1.6 in the precursor of (Gd,Y)Ba 2 Cu 3 O 7 superconducting thin film tapes made by metal organic chemical vapor deposition (MOCVD) at a constant Gd:Y ratio and a fixed Zr content of 7.5% has been studied. The influence of changing the Gd:Y ratio from Gd = 0 to Y= 0 in 0.2 mol steps at a constant Gd + Y content of 1.2 in the precursor has also been investigated at a fixed Zr content of 7.5%. The critical current of these films is found to vary significantly as a function of rare-earth content as well as a function of rare-earth type. Even for a fixed Zr content, it is found that the critical current in the orientation of magnetic field parallel to the a–b plane and that in the orientation of field perpendicular to the a–b plane can be systematically varied with changing Gd + Y content as well as with changing Gd:Y ratio. The nanoscale defect structures along the a–b plane and along the c-axis are found to be sensitive to these changes in rare-earth content and type. (paper)

Favored neutron excitations in superdeformed 147Gd

International Nuclear Information System (INIS)

Theisen, C.; Khadiri, N.; Vivien, J.P.; Ragnarsson, I.; Beausang, C.W.; Beck, F.A.; Belier, G.; Byrski, T.; Curien, D.; de France, G.; Disdier, D.; Duchene, G.; Finck, C.; Flibotte, S.; Gall, B.; Haas, B.; Hanine, H.; Herskind, B.; Kharraja, B.; Merdinger, J.C.; Nourreddine, A.; Nyako, B.M.; Perez, G.E.; Prevost, D.; Stezowski, O.; Rauch, V.; Rigollet, C.; Savajols, H.; Sharpey-Schafer, J.; Twin, P.J.; Wei, L.; Zuber, K.

1996-01-01

Four new superdeformed (SD) bands have been observed in 147 Gd using the EUROGAM II spectrometer. By comparison with 146,148,149 Gd SD bands, we use the effective alignment to assign excited band configurations, with the support of the Nilsson-Strutinsky cranking formalism. The effect of the crossing of the [642]5/2 and [651]1/2 neutron orbitals lying just below the magic N=86 SD shell gap has been investigated for the 146,147,148 Gd bands. Evidence for the [411]1/2 orbital is also given. copyright 1996 The American Physical Society

Ageing effect on the magnetocaloric properties of Gd, Gd5Si1.9Ge2.1 and on the eutectic composition Gd75Cd25

International Nuclear Information System (INIS)

Canepa, F; Cirafici, S; Napoletano, M; Cimberle, M R; Tagliafico, L; Scarpa, F

2008-01-01

The ageing effects due to the interaction with typical working fluids (water and air) of magnetic refrigerant materials have been analysed for up to one year. Among the many compounds reported to exhibit a sufficiently high magnetocaloric effect, we decided to artificially age Gd, which represents the first choice high magnetocaloric element, Gd 5 Si 1.9 Ge 2.1 , belonging to the series Gd 5 (Si x Ge 4-x ) 4 which for x ∼ 0.5 displays a giant magnetocaloric effect, and finally, the eutectic Gd 75 Cd 25 alloy, presenting an almost constant adiabatic temperature rise in an interesting temperature span (260-280 K). Magnetothermal results give evidence that corrosion and corrosion/erosion processes take place with different results on the refrigerant properties of all the materials. The adiabatic temperature rise is strongly reduced due to surface oxidation which lowers thermal conduction while the effect on the refrigerant capacity Q is definitely smaller. The effects of corrosion/erosion processes are confirmed by quantitative chemical analysis performed on the refrigerant fluid before and after the ageing process. Employing working fluids with a reduced corrosive effect but with comparable thermal properties may be a viable way of avoiding corrosion damage; alternatively the use of additives to decrease the corrosive properties of the fluids is strongly suggested

Chemical bonding and magnetic properties of gadolinium (Gd) substituted cobalt ferrite

Energy Technology Data Exchange (ETDEWEB)

Puli, Venkata Sreenivas, E-mail: vspuli@utep.edu [Department of Mechanical Engineering, University of Texas, El Paso, TX 79968 (United States); Adireddy, Shiva [Department of Physics and Engineering Physics, Tulane University, New Orleans, LA 70118 (United States); Ramana, C.V. [Department of Mechanical Engineering, University of Texas, El Paso, TX 79968 (United States)

2015-09-25

Graphical abstract: Room temperature Raman spectra of CoFe{sub 2−x}Gd{sub x}O{sub 4} (CFGO, x = 0.0–0.3) compounds as a function of wavenumber (cm{sup −1}). - Highlights: • Gd substituted ferrites were synthesized under controlled concentration. • Gd ion induced lattice dynamical changes are significant. • Enhanced magnetization is observed upon Gd-incorporation in cobalt ferrite. • A correlation between lattice dynamics and magnetic properties is established. - Abstract: Polycrystalline gadolinium (Gd) substituted cobalt ferrites (CoFe{sub 2−x}Gd{sub x}O{sub 4}; x = 0–0.3, referred to CFGO) ceramics have been synthesized by solid state reaction method. Chemical bonding, crystal structure and magnetic properties of CFGO compounds have been evaluated as a function of Gd-content. X-ray diffraction (XRD) and Raman spectroscopic analyses confirmed the formation of inverse spinel cubic structure. However, a secondary ortho-ferrite phase (GdFeO{sub 3}) nucleates for higher values of Gd-content. A considerable increase in the saturation magnetization has been observed upon the initial substitution of Gd (x = 0.1). The saturation magnetization drastically decreases at higher Gd content (x ⩾ 0.3). No contribution from ortho-ferrite GdFeO{sub 3} phase is noted to the magnetic properties. The increase in the magnetic saturation magnetization is attributed to the higher magnetic moment of Gd{sup 3+} (4f{sup 7}) residing in octahedral sites is higher when compared to that of Fe{sup 3+} (3d{sup 5}) and as well due to the migration of Co{sup 2+} (3d{sup 7}) ions from the octahedral to the tetrahedral sites with a magnetic moment aligned anti-parallel to those of rare earth (RE{sup 3+}) ions in the spinel lattice. Increase in coercivity with increase in Gd{sup 3+} is content is attributed to magnetic anisotropy in the ceramics.

Gd-HOPO Based High Relaxivity MRI Contrast Agents

Energy Technology Data Exchange (ETDEWEB)

Datta, Ankona; Raymond, Kenneth

2008-11-06

Tris-bidentate HOPO-based ligands developed in our laboratory were designed to complement the coordination preferences of Gd{sup 3+}, especially its oxophilicity. The HOPO ligands provide a hexadentate coordination environment for Gd{sup 3+} in which all he donor atoms are oxygen. Because Gd{sup 3+} favors eight or nine coordination, this design provides two to three open sites for inner-sphere water molecules. These water molecules rapidly exchange with bulk solution, hence affecting the relaxation rates of bulk water olecules. The parameters affecting the efficiency of these contrast agents have been tuned to improve contrast while still maintaining a high thermodynamic stability for Gd{sup 3+} binding. The Gd- HOPO-based contrast agents surpass current commercially available agents ecause of a higher number of inner-sphere water molecules, rapid exchange of inner-sphere water molecules via an associative mechanism, and a long electronic relaxation time. The contrast enhancement provided by these agents is at least twice that of commercial contrast gents, which are based on polyaminocarboxylate ligands.

Interfacial exchange, magnetic coupling and magnetoresistance in ultra-thin GdN/NbN/GdN tri-layers

Science.gov (United States)

Takamura, Yota; Goncalves, Rafael S.; Cascales, Juan Pedro; Altinkok, Atilgan; de Araujo, Clodoaldo I. L.; Lauter, Valeria; Moodera, Jagadeesh S.; MIT Team

Superconducting spin-valve structures with a superconductive (SC) spacer sandwiched between ferromagnetic (FM) insulating layers [Li PRL 2013, Senapati APL 2013, Zhu Nat. Mat. 2016.] are attractive since the SC and FM characteristics can mutually be controlled by the proximity effect. We investigated reactively sputtered GdN/NbN/GdN tri-layer structures with various (SC) NbN spacer thicknesses (dNbN) from superconducting to normal layers. Magnetoresistive behavior similar to GMR in metallic magnetic multilayers was observed in the tri-layers with dNbN between 5-10 monolayers (ML), where thinner NbN layers did not show superconductivity down to 4.2 K. The occurrence of GMR signal indicates the presence of a ML of FM metallic layers at the GdN/NbN interfaces. Susceptibility and transport measurements in these samples revealed that the interface layers (ILs) are ferromagnetically coupled with adjacent GdN layers. The thickness of each of the IL is deduced to be about 1.25 ML, and as a result for dNbN magnetically coupled and switched simultaneously. These findings and interfacial characterization by various techniques will be presented. Work supported by NSF and ONR Grants.

Favored neutron excitations in superdeformed Gd-147

NARCIS (Netherlands)

Theisen, C; Khadiri, N; Vivien, JP; Ragnarsson, J; Beausang, CW; Beck, FA; Belier, G; Byrski, T; Curien, D; deFrance, G; Disdier, D; Duchene, G; Finck, C; Flibotte, S; Gall, B; Haas, B; Hanine, H; Herskind, B; Kharraja, B; Merdinger, JC; Nourreddine, A; Nyako, BM; Perez, GE; Prevost, D; Stezowski, O; Rauch, I; Rigollet, C; Savajols, H; SharpeySchafer, J; Twin, PJ; Wei, L; Zuber, K

1996-01-01

Four new superdeformed (SD) bands have been observed in Gd-147 using the EUROGAM II spectrometer. By comparison with (146,148,149),Gd SD bands, we use the effective alignment to assign excited band configurations, with the support of the Nilsson-Strutinsky cranking formalism. The effect of the

Dilution Refrigeration of Multi-Ton Cold Masses

CERN Document Server

Wikus, P; CERN. Geneva

2007-01-01

Dilution refrigeration is the only means to provide continuous cooling at temperatures below 250 mK. Future experiments featuring multi-ton cold masses require a new generation of dilution refrigeration systems, capable of providing a heat sink below 10 mK at cooling powers which exceed the performance of present systems considerably. This thesis presents some advances towards dilution refrigeration of multi-ton masses in this temperature range. A new method using numerical simulation to predict the cooling power of a dilution refrigerator of a given design has been developed in the framework of this thesis project. This method does not only allow to take into account the differences between an actual and an ideal continuous heat exchanger, but also to quantify the impact of an additional heat load on an intermediate section of the dilute stream. In addition, transient behavior can be simulated. The numerical model has been experimentally verified with a dilution refrigeration system which has been designed, ...

Humus application produced by organic waste transformation in growing lands

International Nuclear Information System (INIS)

Gutierrez Martinez, M. G.; Morales Osorio, A.; Gutierrez Martinez, R.; Marquez Monsalvo, J. J.; Reyes Reyes, G.

2009-01-01

Every year in Mexico are produced more tons of garbage (19 874 259 tons) than tons of corn (18 309 000 tons). Fifty percent of domestic garbage is constituted by organic remainders. In december 2005 began de project Biotransformation of Organic Remainders in Humus for its Application in growing Lands with the purpose to prove the methods of: 1) Natural outdoors transformation, 2) Accelerated fermentation with thermophilic and mesophilic microorganisms, and 3) Transformation with microorganisms such as californian red worm, Eisenia andrei, to transform efficiently fruits and vegetables remainders. (Author)

Multiorgan gadolinium (Gd) deposition and fibrosis in a patient with nephrogenic systemic fibrosis--an autopsy-based review

DEFF Research Database (Denmark)

Sanyal, Soma; Marckmann, Peter; Scherer, Susanne

2011-01-01

tissues of NSF patients, predominantly at the bulk chemical level. The distribution of Gd at the histologic level of organs other than skin has not been reported previously. METHODS: We analysed tissues from an autopsy case with verified advanced NSF by light microscopy and scanning electron microscopy......), kidney, lymph node, skeletal muscle, dura mater and cerebellum of the NSF autopsy case, primarily in vascular walls. Some, but not all, Gd deposits were seen in fibrotic areas. Literature review highlighted that non-specific tissue fibrosis and calcification are frequent findings in tissues of patients...

Magnetic and structural studies on nanostructured Gd/Cr multilayer films

International Nuclear Information System (INIS)

Gadioli, G.Z.; Rouxinol, F.P.; Gelamo, R.V.; Cardoso, L.P.; Gama, S.; Bica de Moraes, M.A.

2013-01-01

Investigations of magnetic phases, transition temperatures and coercivity were performed in multilayered Gd/Cr films as a function of the crystalline state and morphology of the Gd layers. The films were deposited by dc magnetron sputtering at three substrate temperatures, T s , (room temperature, 300 and 500 °C). The Gd and Cr thicknesses were of 10 and 30 nm, respectively. Two series of three films were prepared. In one of the series, the films had a single Gd/Cr bilayer; in the other, 15 bilayers. The discontinuous or granular nature of the Gd layers was revealed by scanning electron microscopy Grazing incidence angle x-ray diffraction was used to investigate the crystalline state of the Gd and Cr layers. These techniques revealed that grain average size and crystalline order increase with increasing T s . From dc magnetic measurements, the co-existence of ferromagnetic and superferromagnetic phases in the Gd layers was observed, and Curie transition temperatures, T C , were determined. High coercive fields at low temperature (2 K) were measured in hysteresis cycles. Field-cooled and zero field-cooled magnetizations as functions of temperature curves exhibited, for some of the samples, a low temperature peak suggesting a freezing transition to a cluster glass state. This was confirmed by complementary ac-susceptibility measurements carried out as a function of temperature, for various frequencies of the ac field. Some results of this work – the decline in T C for decreasing Gd grain size, the high coercive field and its dependence on particle size, and the behavior of the magnetization at low temperatures for the sample deposited at room temperature – are discussed in terms of finite size and surface effects in nanosized particles. - Highlights: • Sputter-deposited Gd/Cr multilayer films with nanostructured Gd layers • Ferromagnetic and superferromagnetic phases are observed. • Ferromagnetic phase dependent of the deposition temperature • Improved

Autoclave growth, magnetic, and optical properties of GdB6 nanowires

Science.gov (United States)

Han, Wei; Wang, Zhen; Li, Qidong; Liu, Huatao; Fan, Qinghua; Dong, Youzhong; Kuang, Quan; Zhao, Yanming

2017-12-01

High-quality single crystalline gadolinium hexaboride (GdB6) nanowires have been successfully prepared at very low temperatures of 200-240 °C by a high pressure solid state (HPSS) method in an autoclave with a new chemical reaction route, where Gd, H3BO3, Mg and I2 were used as raw materials. The crystal structure, morphology, valence, magnetic and optical absorption properties were investigated using XRD, FESEM, HRTEM, XPS, SQUID magnetometry and optical measurements. HRTEM images and SAED patterns reveal that the GdB6 nanowires are single crystalline with a preferred growth direction along [001]. The XPS spectrum suggests that the valence of Gd ion in GdB6 is trivalent. The effective magnetic momentum per Gd3+ in GdB6 is about 6.26 μB. The optical properties exhibit weak absorption in the visible light range, but relatively strong absorbance in the NIR and UV range. Low work function and high NIR absorption can make GdB6 nanowires a potential solar radiation shielding material for solar cells or other NIR blocking applications.

Octahedral tilt independent magnetism in confined GdTiO3 films

Science.gov (United States)

Need, R. F.; Isaac, B. J.; Kirby, B. J.; Borchers, J. A.; Stemmer, S.; Wilson, Stephen D.

2018-03-01

Low temperature polarized neutron reflectometry measurements are presented, exploring the evolution of ferrimagnetism in thin GdTiO3 films embedded within a SrTiO3 matrix. In GdTiO3 films thinner than ˜4 nm, the TiO6 octahedral tilts endemic to GdTiO3 coherently relax toward the undistorted, cubic phase of SrTiO3. Our measurements indicate that the ferrimagnetic state within the GdTiO3 layers survives as these TiO6 octahedral tilts are suppressed. Furthermore, our data suggest that layers of suppressed magnetization (i.e., magnetic dead layers) develop within the GdTiO3 layer at each GdTiO3/SrTiO3 interface and explain the apparent magnetization suppression observed in thin GdTiO3 films when using volume-averaged techniques. Our data show that the low temperature magnetic moment inherent to the core GdTiO3 layers is only weakly impacted as the octahedral tilt angles are suppressed by more than 50% and the t2 g bandwidth is dramatically renormalized.

Advances in enlargement of melt-textured Gd-Ba-Cu-O superconductors

International Nuclear Information System (INIS)

Nariki, S; Sakai, N; Kita, M; Fujikura, M; Murakami, M; Hirabayashi, I

2006-01-01

We investigated the fabrication of melt-textured Gd-Ba-Cu-O bulk superconductors with the employment of a Gd 2 BaO 4 (Gd210)-BaCuO 2 -CuO precursor. This enabled us to synthesize a very large Gd-Ba-Cu-O bulk superconductor, 140 mm in diameter. The trapped field distribution measured at 77 K revealed that the sample had no serious cracks, and the maximum field was 2.3 T. The formation behaviour and depressing mechanism of cracking were studied using sintered Gd210-containing precursors. The Ba-Cu-O component in the precursor melted at around 900 deg. C. The formation of such a liquid phase enhanced the densification of the precursor by liquid phase sintering. The mechanical strength of the sintered precursor was increased compared to the conventional Gd123-Gd211 precursor. This will be effective in preventing crack formation in the texturing process of large single-grain samples. The superconducting properties of the bulk sample fabricated from Gd210-containing precursor have been discussed

μ+ depolarization in AlGd alloys

International Nuclear Information System (INIS)

Kohn, S.; Brown, J.A.; Heffner, R.H.; Huang, C.Y.; Kitchens, T.A. Jr.; Leon, M.; Olsen, C.E.; Schillaci, M.E.

1979-01-01

The μ + depolarization rate in dilute AlGd alloys containing 50 and 450 atomic ppm Gd was measured in a transverse field of 80 Oe over the temperature range 6-300 K. For both alloys, Λ increased dramatically above 200 K, reaching values of 0.69 and 0.93 μs -1 , respectively, near room temperature. The results are interpreted as providing evidence for a thermally-activated trapping mechanism. (Auth.)

Single step synthesis of GdAlO3 powder

International Nuclear Information System (INIS)

Sinha, Amit; Nair, S.R.; Sinha, P.K.

2011-01-01

Research highlights: → First report on direct formation of GdAlO 3 powder using a novel combustion process. → Study of combustion characteristics of Gd(NO 3 ) 3 and Al(NO 3 ) 3 towards three fuels. → Preparation of highly sinterable GdAlO 3 powders through fuel-mixture approach. → Significant reduction in energy consumption for production of GdAlO 3 sintered body. - Abstract: A novel method for preparation of nano-crystalline gadolinium aluminate (GdAlO 3 ) powder, based on combustion synthesis, is reported. It was observed that aluminium nitrate and gadolinium nitrate exhibit different combustion characteristics with respect to urea, glycine and β-alanine. While urea was proven to be a suitable fuel for direct formation of crystalline α-Al 2 O 3 from its nitrate, glycine and β-alanine are suitable fuels for gadolinium nitrate for preparation of its oxide after combustion reaction. Based on the observed chemical characteristics of gadolinium and aluminium nitrates with respect to above mentioned fuels for the combustion reaction, the fuel mixture composition could be predicted that could lead to phase pure perovskite GdAlO 3 directly after the combustion reaction without any subsequent calcination step. The use of single fuel, on the other hand, leads to formation of amorphous precursor powders that call for subsequent calcination for the formation of crystalline GdAlO 3 . The powders produced directly after combustion reactions using fuel mixtures were found to be highly sinterable. The sintering of the powders at 1550 o C for 4 h resulted in GdAlO 3 with sintered density of more than 95%. T.D.

GdNCT of spontaneous canine melanoma

International Nuclear Information System (INIS)

Mitin, V.N.; Kulakov, V.N.; Khokhlov, V.F.

2006-01-01

The effectiveness of GdNCT has been studied in dogs with spontaneous melanoma of the mucousmembrane of the oral cavity patients on the NCT base at the IRT MEPhI reactor. The control group with melanomas was treated with neutrons. Fourteen canine patients were selected in the Clinic of Experimental Therapy affiliated with the RCRC RAMS. The calculation of doses has shown that the total dose of energy release depending on Gd concentration in the target can be several times higher than the dose produced by the reactor neutron beam. The calculations were carried out using the diffusion pharmacokinetic model. The gadolinium drug dipentast was administered intratumorally immediately prior to irradiation. The tumor size was estimated by measuring it in three projections. The tumor was irradiated for 60-90 minutes with a thermal neutron flux of 0.7x10 9 n/cm 2 s. The dose on tumor was 80-120 Gy, on surrounding tissues - 12-15 Gy. The treatment plan included immunotherapy with Roncoleikin in a dose of (15-10)x10 3 IE/kg. The results of GdNCT are still under observation. The results conform to those obtained by us earlier in cell cultures and inoculated experimental tumors. GdNCT is also effective in combination with immunotherapy. (author)

Magnetic short-range order in Gd

International Nuclear Information System (INIS)

Child, H.R.

1978-01-01

The magnetic short-range order in a ferromagnetic, isotopically enriched 160 Gd metal single crystal has been investigated by quasielastic scattering of 81-meV neutrons. Since Gd behaves as an S-state ion in the metal, little anisotropy is expected in its magnetic behavior. However, the data show that there is anisotropic short-range order present over a large temperature interval both above and below T/sub C/. The data have been analyzed in terms of an Ornstein-Zernike Lorentzian form with anisotropic correlation ranges. These correlation ranges as deduced from the observed data behave normally above T/sub C/ but seem to remain constant over a fairly large interval below T/sub C/ before becoming unobservable at lower temperatures. These observations suggest that the magnetic ordering in Gd may be a more complicated phenomenon than first believed

Comparison of gadobenate dimeglumine (Gd-BOPTA) with gadopentetate dimeglumine (Gd-DTPA) for enhanced MR imaging of brain and spine tumours in children

Energy Technology Data Exchange (ETDEWEB)

Colosimo, Cesare [Univ. Annunzio, Chieti (Italy). Dept. of Clinical Sciences; Demaerel, Philippe [Univ. Hospital Leuven (Belgium); Tortori-Donati, Paolo [Inst. Gaslini, Genoa (Italy); Christophe, Catherine [Hopital Universitaire des Efants, Brussels (Belgium); Buchem, Mark van [Univ. Hospital Leiden (Netherlands); Hoegstroem, Barry; Pirovano, Gianpaolo; Shen, Ningyan; Spinazzi, Alberto [Worldwide Medical Affairs, Bracco Diagnostics, Inc., Princeton, NJ (United States); Kirchin, Miles A. [Worldwide Medical Affairs, Bracco Imaging SpA, Milan (Italy)

2005-05-01

Sixty-three subjects, aged 6 months to 16 years, who were enrolled in a prospective, fully blinded, randomized parallel-group phase III clinical trial, received 0.1 mmol/kg doses of either Gd-BOPTA (n=29) or Gd-DTPA (n=34). The MR images were acquired before and within 10 min of contrast agent injection. The primary objective was to compare the difference from pre-dose to post-dose lesion visualization between Gd-BOPTA and Gd-DTPA. Lesion visualization was determined as the sum of individual scores for three criteria of lesion morphological characteristics (lesion border delineation, internal morphology, and contrast enhancement), each assessed qualitatively using 4-point scales. Quantitative evaluation compared changes in lesion-to-background (LBR) and contrast-to-noise (CNR) ratios and per cent enhancement. Monitoring for adverse events and evaluation of vital signs and laboratory values was performed. Pre-dose to post-dose changes in lesion visualization were significantly better for Gd-BOPTA for both lesion level (2.68{+-}2.17 vs. 1.05{+-}1.90, P=0.0106) and patient level (2.55{+-}2.18 vs. 1.14{+-}1.68, P=0.0079) comparisons. The mean pre-dose to post-dose change in CNR was greater for Gd-BOPTA (9.13{+-}15.36) than Gd-DTPA (2.18{+-}9.90), but the difference was only marginally significant (P=0.0779; 95% CI: -0.553, 14.454) because of wide variations of signal intensity between lesions. Similar findings were obtained for LBR and per cent enhancement. No differences between the agents were noted in terms of safety parameters. (orig.)

Ganglioside GD2 in reception and transduction of cell death signal in tumor cells

International Nuclear Information System (INIS)

Doronin, Igor I; Vishnyakova, Polina A; Kholodenko, Irina V; Ponomarev, Eugene D; Ryazantsev, Dmitry Y; Molotkovskaya, Irina M; Kholodenko, Roman V

2014-01-01

Ganglioside GD2 is expressed on plasma membranes of various types of malignant cells. One of the most promising approaches for cancer immunotherapy is the treatment with monoclonal antibodies recognizing tumor-associated markers such as ganglioside GD2. It is considered that major mechanisms of anticancer activity of anti-GD2 antibodies are complement-dependent cytotoxicity and/or antibody-mediated cellular cytotoxicity. At the same time, several studies suggested that anti-GD2 antibodies are capable of direct induction of cell death of number of tumor cell lines, but it has not been investigated in details. In this study we investigated the functional role of ganglioside GD2 in the induction of cell death of multiple tumor cell lines by using GD2-specific monoclonal antibodies. Expression of GD2 on different tumor cell lines was analyzed by flow cytometry using anti-GD2 antibodies. By using HPTLC followed by densitometric analysis we measured the amount of ganglioside GD2 in total ganglioside fractions isolated from tumor cell lines. An MTT assay was performed to assess viability of GD2-positive and -negative tumor cell lines treated with anti-GD2 mAbs. Cross-reactivity of anti-GD2 mAbs with other gangliosides or other surface molecules was investigated by ELISA and flow cytometry. Inhibition of GD2 expression was achieved by using of inhibitor for ganglioside synthesis PDMP and/or siRNA for GM2/GD2 and GD3 synthases. Anti-GD2 mAbs effectively induced non-classical cell death that combined features of both apoptosis and necrosis in GD2-positive tumor cells and did not affect GD2-negative tumors. Anti-GD2 mAbs directly induced cell death, which included alteration of mitochondrial membrane potential, induction of apoptotic volume decrease and cell membrane permeability. This cytotoxic effect was mediated exclusively by specific binding of anti-GD2 antibodies with ganglioside GD2 but not with other molecules. Moreover, the level of GD2 expression correlated with

Magnetic resonance imaging of human cerebral infarction: Enhancement with Gd-DTPA

Energy Technology Data Exchange (ETDEWEB)

Imakita, S.; Nishimura, T.; Naito, H.; Yamada, N.; Yamamoto, K.; Takamiya, M.; Yamada, Y.; Sakashita, Y.; Minamikawa, J.; Kikuchi, H.

1987-09-01

Five patients (1 female and 4 males) with cerebral infarction of 4 h to 27 months duration were studied 9 times with magnetic resonance (MR) using Gd-DTPA. Spinecho (SE) MR images (MRI) were obtained before and after the administration of Gd-DTPA, and correlative CT scans were performed on the same day. In 2 cases, 4 h and 27 months after the ictus, there was no enhancement with Gd-DTPA. There was faint enhancement in 2 cases with cerebral infarction of about 24 h duration and obvious enhancement in all cases in the subacute stage. Compared with enhanced CT, MR using Gd-DTPA demonstrated more obvious enhancement of infarcted areas. MR enhancement using Gd-DTPA showed a gradual increase and the accumulated Gd-DTPA in infarcted areas slowly diffused to the periphery. MR enhancement with Gd-DTPA is similar to that of enhanced CT, but may be more sensitive in the detection of blood brain barrier breakdown.

Crystal structure and electronic states of Co and Gd ions in a Gd0.4Sr0.6CoO2.85 single crystal

Science.gov (United States)

Platunov, M. S.; Dudnikov, V. A.; Orlov, Yu. S.; Kazak, N. V.; Solovyov, L. A.; Zubavichus, Ya. V.; Veligzhanin, A. A.; Dorovatovskii, P. V.; Vereshchagin, S. N.; Shaykhutdinov, K. A.; Ovchinnikov, S. G.

2016-02-01

X-ray diffraction and X-ray absorption near edge structure (XANES) spectra have been measured at the Co K-edge and Gd L 3-edge in GdCoO3 and Gd0.4Sr0.6CoO2.85 cobaltites. The effect of Sr substitution on the crystal structure and electronic and magnetic states of Co3+ ions in a Gd0.4Sr0.6CoO2.85 single crystal has been analyzed. The XANES measurements at the Co K-edge have not showed a noticeable shift of the absorption edge with an increase in the concentration of Sr. This indicates that the effective valence of cobalt does not change. An increase in the intensity of absorption at the Gd L 3-edge is due to an increase in the degree of hybridization of the Gd(5 d) and O(2 p) states. The effect of hole doping on the magnetic properties results in the appearance of the ferromagnetic component and in a significant increase in the magnetic moment.

Strongly coupled band in {sup 140}Gd

Energy Technology Data Exchange (ETDEWEB)

Falla-Sotelo, F.; Oliveira, J.R.B.; Rao, M.N. [Instituto de Fisica, Universidade de Sao Paulo, Sao Paulo (Brazil)] (and others)

2005-07-01

Several high-K states are known to exist in the mass 130-140 region. For the N=74 even-even isotopes, K{pi} = 8{sup -} isomers, with lifetimes ranging from ns to ms, are known in {sup 128}Xe, {sup 130}Ba, {sup 132}Ce, {sup 134}Nd, {sup 136}Sm, and {sup 138}Gd[. In {sup 140}Gd, we have observed for the first time a band also based on an I{pi} = 8{sup -} state. This could be the first case of a K{pi} = 8{sup -} state observed in an N=76 even-even isotope. The systematics of the K{pi} = 8{sup -} isomeric states in N=74 isotopes has been studied by A.M. Bruce et al. These states decay towards the K = 0 ground state band, and the transitions are K-forbidden. The {sup 140}Gd case presents strong similarities but also some significant differences with relation to the N=74 isotopes. We propose the same configuration but with larger deformation in {sup 140}Gd.

MR lymphography with macromolecular Gd-DTPA compounds

International Nuclear Information System (INIS)

Hamm, B.; Wagner, S.; Branding, G.; Taupitz, M.; Wolf, K.J.

1990-01-01

This paper investigates the suitability of macromolecular Gd-DTPA compounds as signal-enhancing lymphographic agents in MR imaging. Two Gd-DTPA polylysin compounds and Gd-DTPA albumin, with molecular weights of 48,000,170,000, and 87,000 daltons, respectively, were tested in rabbits at gadolinium doses of 5 and 15 μmol per animal. Three animals were examined at each dose with T1-weighted sequences. The iliac lymph nodes were imaged prior to and during unilateral endolymphatic infusion into a femoral lymph vessel as well as over a period of 2 hours thereafter. All contrast media showed a homogeneous and pronounced signal enhancement in the lymph nodes during infusion at both doses

The 500 deg. C isothermal section of the Gd-Tb-Co ternary system

International Nuclear Information System (INIS)

Zhou, K.W.; Zhuang, Y.H.; Li, J.Q.; Zhu, Q.M.; Deng, J.Q.

2006-01-01

The isothermal section of the phase diagram of the Gd-Tb-Co ternary system at 500 deg. C was investigated by X-ray powder diffraction, differential thermal analysis and metallographic analysis techniques. In this isothermal section, there are nine single-phase regions, eight two-phase regions and none three-phase region. No ternary compound was found. The compounds Gd 2 Co 17 and Tb 2 Co 17 , Gd 2 Co 7 and Tb 2 Co 7 , GdCo 3 and TbCo 3 , GdCo 2 and TbCo 2 , Gd 4 Co 3 and Tb 4 Co 3 , Gd 12 Co 7 and Tb 12 Co 7 , Gd 3 Co and Tb 3 Co, Gd and Tb form a continuous series of solid solutions. In addition, we experimentally determined the vertical section of pseudobinary system and the Curie temperature of Gd 1-x Tb x Co 2 (x from 0 to 1) series alloys

Thermal expansion of UO2-Gd2O3 fuel pellets

International Nuclear Information System (INIS)

Une, Katsumi

1986-01-01

In recent years, more consideration has been given to the application of UO 2 -Gd 2 O 3 burnable poison fuel to LWRs in order to improve the core physics and to extend the burnup. It has been known that UO 2 forms a single phase cubic fluorite type solid solution with Gd 2 O 3 up to 20 - 30 wt.% above 1300 K. The addition of Gd 2 O 3 to UO 2 lattices changes the properties of the fuel pellets. The limited data on the thermal expansion of UO 2 -Gd 2 O 3 fuel exist, but those are inconsistent. UO 2 -Gd 2 O 3 fuel pellets were fabricated, and the linear thermal expansion of UO 2 and UO 2 -(5, 8 and 10 wt.%)Gd 2 O 3 fuel pellets was measured with a differential dilatometer over the temperature range of 298 - 1973 K. A sapphire rod of 6 mm diameter and 15.5 mm length was used as the reference material. After the preheating cycle, the measurement was performed in argon atmosphere. The results for UO 2 pellets showed excellent agreement with the data in literatures. The linear thermal expansion of UO 2 -Gd 2 O 3 fuel pellets showed the increase with increasing the Gd 2 O 3 content. Consideration must be given to this excessive expansion in the fuel design of UO 2 -Gd 2 O 3 pellets. The equations for the linear thermal expansion and density of UO 2 -Gd 2 O 3 fuel pellets were derived by the method of least squares. (Kako, I.)

Molecular electrophosphorescence in (Sm, Gd)-β-diketonate complex blend for OLED applications

International Nuclear Information System (INIS)

Reyes, R.; Cremona, M.; Teotonio, E.E.S.; Brito, H.F.; Malta, O.L.

2013-01-01

In this work the preparation and characterization of the triple-layer organic light-emitting diode (OLED) using a mixture of the samarium and gadolinium β-diketonate complexes [Sm 0.5 Gd 0.5 (TTA) 3 (TPPO) 2 ] as emitting layer is reported. The OLED's devices contain 1-(3-methylphenyl)-1,2,3,4-tetrahydroquinoline-6-carboxyaldehyde-1, 1'-diphenylhydrazone (MTCD) as hole-transporting layer and tris(8-hydroxyquinoline aluminum) (Alq 3 ) as electron transporting layer. The electroluminescence spectrum present emission narrow bands from the 4 G 5/2 → 6 H J transitions (where J=5/2, 7/2 and 9/2) characteristic of the Sm 3+ ion. These sharp lines are overlapped with a broad band attributed to the electrophosphorescence from the T 1 →S 0 transition in the ligand TTA. The intramolecular energy transfer is discussed and applied on the change of the emission color of the organic LEDs at different bias voltages. - Highlights: ► Samarium and gadolinium complexes. ► OLED with complex blend (Sm,Gd). ► Electrophosphorescence emission detection. ► Application in OLED changing the color emission.

Two new glucose 6-phosphate dehydrogenase variants associated with congenital nonspherocytic hemolytic anemia found in Japan: GD(-) Tokushima and GD(-) Tokyo.

Science.gov (United States)

Miwa, S; Ono, J; Nakashima, K; Abe, S; Kageoka, T

1976-01-01

Two new variants of glucose 6-phosphate dehydrogenase (G6PD) deficiency associated with chronic nonspherocytic hemolytic anemia were discovered in Japan. Gd(-) Tokushima was found in a 17-years-old male whose erythrocytes contained 4.4% of normal enzyme activity. Partially purified enzyme revealed a main band of normal electrophoretic mobility with additional two minor bands of different mobility; normal Km G6P, and Km NADP five-to sixfold higher than normal; normal utilization of 2-deoxy-G6P, galactose-6P, and deamino-NADP; marked thermal instability; a normal pH curve; and normal Ki NADPH. The hemolytic anemia was moderate to severe. Gd(-) Tokyo was characterized from a 15-year-old male who had chronic nonspherocytic hemolytic anemia of mild degree. The erythrocytes contained 3% of normal enzyme activity, and partially purified enzyme revealed slow electrophoretic mobility (90% of normal for both a tris-hydrochloride buffer system and a tris-EDTA-borate buffer system, and 70% of normal for a phosphate buffer system); normal Km G6P and Km NADP; normal utilization of 2-deoxy-G6P, galactose-6P, and deamino-NADP; greatly increased thermal instability; a normal pH curve; and normal Ki NADPH. These two variants are clearly different from hitherto described G6PD variants, including the Japanese variants Gd(-) Heian and Gd(-) Kyoto. The mothers of both Gd(-) Tokushima and Gd(-) Tokoyo were found to be heterozygote by an ascorbate-cyanide test.

(Gd1−xErx)5Si2Ge2 compounds

Indian Academy of Sciences (India)

Gd metal (3 N) by arc melting, and then annealed at 1523 K (3 h). The phase, microstructure, Curie ... The temperature of magnetic transition decreases linearly from 281 K to 177 K with the increase of Er content from x = 0–0·2. ... Gd5Si2Ge2 serial compounds, different rare earth elements substituted for Gd in Gd5(Six ...

Gd-DTPA: a bowel contrast agent for magnetic resonance imaging of the abdomen

International Nuclear Information System (INIS)

Vlahos, L.; Gouliamos, A.; Clauss, W.; Kalovidouris, A.; Hadjiioannou, A.; Athanasopoulou, A.; Trakadas, S.; Papavasiliou, C.

1992-01-01

Forty patients with suspected pathology in the abdomen and pelvis have been investigated with MRI before and after administration of Gd-DTPA as an oral or rectal solution. The findings are analysed with respect to: (a) filling of the GI tract; (b) contrast in the region of interest, surrounding fat and vessels; (c) diagnostic yield in comparison to non-enhanced MRI and contrast CT. At a concentration of 1 mmol/l Gd-DTPA provided consistent positive contrast in the stomach and bowel in all cases. In 57.5% of cases we achieved complete filling of the GI tract. The opacification in the region of interest was good or satisfactory in 90% of cases. The diagnostic value of contrast MRI was better in 93% of cases than the non-enhanced MRI of the abdomen. In comparison with contrast CT, the contrast MRI was better or of the same value in 92% of cases. Despite the disadvantage of poor fat-to-bowel contrast (35% of cases were classified as poor), it is concluded that Gd-DTPA-enhanced MRI provides good delineation of organs adjacent to the bowel so this contrast agent has potential for a future role in abdominal MRI. (orig.)

Gd-DTPA: a bowel contrast agent for magnetic resonance imaging of the abdomen

Energy Technology Data Exchange (ETDEWEB)

Vlahos, L. [Dept. of Radiology, Univ. of Athens, Areteion Hospital (Greece); Gouliamos, A. [Dept. of Radiology, Univ. of Athens, Areteion Hospital (Greece); Clauss, W. [Schering A. G., Berlin (Germany); Kalovidouris, A. [Dept. of Radiology, Univ. of Athens, Areteion Hospital (Greece); Hadjiioannou, A. [Dept. of Radiology, Univ. of Athens, Areteion Hospital (Greece); Athanasopoulou, A. [Dept. of Radiology, Univ. of Athens, Areteion Hospital (Greece); Trakadas, S. [Dept. of Radiology, Univ. of Athens, Areteion Hospital (Greece); Papavasiliou, C. [Dept. of Radiology, Univ. of Athens, Areteion Hospital (Greece)

1992-08-01

Forty patients with suspected pathology in the abdomen and pelvis have been investigated with MRI before and after administration of Gd-DTPA as an oral or rectal solution. The findings are analysed with respect to: (a) filling of the GI tract; (b) contrast in the region of interest, surrounding fat and vessels; (c) diagnostic yield in comparison to non-enhanced MRI and contrast CT. At a concentration of 1 mmol/l Gd-DTPA provided consistent positive contrast in the stomach and bowel in all cases. In 57.5% of cases we achieved complete filling of the GI tract. The opacification in the region of interest was good or satisfactory in 90% of cases. The diagnostic value of contrast MRI was better in 93% of cases than the non-enhanced MRI of the abdomen. In comparison with contrast CT, the contrast MRI was better or of the same value in 92% of cases. Despite the disadvantage of poor fat-to-bowel contrast (35% of cases were classified as poor), it is concluded that Gd-DTPA-enhanced MRI provides good delineation of organs adjacent to the bowel so this contrast agent has potential for a future role in abdominal MRI. (orig.)

Energy transfer mechanism from Gd3+ to Sm3+ in K3Gd(PO4)2:Sm3+ phosphor

International Nuclear Information System (INIS)

Gupta, Palvi; Bedyal, A K; Kumar, Vinay; Khajuria, Y; Sharma, Vishal; Ntwaeaborwa, O M; Swart, H C

2015-01-01

Undoped K 3 Gd(PO 4 ) 2 and trivalent samarium (0.5–2.5 mol%) doped K 3 Gd(PO 4 ) 2 phosphors were synthesized by the solid-state method. The phase formation, optical and luminescence properties were investigated by x-ray diffraction (XRD), diffuse reflectance (DR) spectroscopy, and photoluminescence (PL) spectroscopy. The fluorescence decay spectra of the obtained phosphors were also recorded to study the energy transfer from sensitizer (Gd 3+ ) to activator (Sm 3+ ). Energy transfer effects from sensitizer to activator caused by rare-earth ions were mainly observed in the obtained PL and lifetime spectra. The decay curves of K 3 Gd(PO 4 ) 2 phosphor with different Sm 3+ ions concentrations were found to be non-exponential and the data is well fitted with the Inokuti–Hirayama (I–H) model. The energy transfer parameters such as critical distance for the transfer processes were determined. The Commission Internationale de l’Eclairage (CIE) chromatic coordinates and color-correlated temperature were also determined for the prepared phosphor. (paper)

The Application of CPA to Calculations of the Mean Magnetic Moment in the Gd1-xNi, Gd1-xFe, Gd1xCox, and Y1-xCox Intermetallic Compounds

DEFF Research Database (Denmark)

Szpunar, B.; Kozarzewski, B.

1977-01-01

with a narrow d-band is considered. The magnetic moment of the alloy at zero temperature is calculated within the molecular field and Hartree-Fock approximations. Disorder is treated in the coherent potential approximation. Results are in good agreement with the experimental data obtained for the crystalline......Calculations are made of the mean magnetic moment per atom of the transition metal and the rare-earth metal in the intermetallic compounds, Gd1-x,Nix, Gd1-x Fex, Gd1-x Cox, and Y1-x Cox. A simple model of the disordered alloy consisting of spins localized on the rare-earth atoms and interacting...

Segregation of solute atoms to interphase boundaries in GdNi{sub 2}

Energy Technology Data Exchange (ETDEWEB)

Murray, Ryan; Banerjee, Debashis; Collins, Gary S., E-mail: collins@wsu.edu [Washington State University, Department of Physics and Astronomy (United States); Zacate, Matthew O. [Northern Kentucky University, Department of Physics and Geology (United States)

2017-11-15

Lattice locations of {sup 111}In impurity probe atoms in intermetallic GdNi{sub 2} were studied as a function of alloy composition and temperature using perturbed angular correlation spectroscopy (PAC). Measurements were made on a pair of samples that were richer and poorer in Gd. Three nuclear quadrupole interaction signals were detected and their equilibrium site fractions were measured up to 700 {sup ∘}C. Two signals have well-defined electric field gradients (EFGs) and are attributed to In-probes on Gd- and Ni-sites in a well-ordered lattice. A third signal exhibiting strong inhomogeneous broadening was observed at low temperature in Gd-richer samples. This is attributed to segregation of the In-probes to phase boundaries (PB) of minor volume fractions of the neighboring GdNi phase. A measurement made on a stoichiometric GdNi sample exhibited the same inhomogeneously broadened signal, indicating that In-probes prefer to occupy PB and/or grain boundary sites in GdNi rather than the well-defined Gd- and Ni-sites. Changes in site fractions were reversible above 300 {sup ∘}C, indicating that probe atoms equilibrate among all lattice locations within a time period of one day. Thus, PB sites provide lower enthalpy environments for In-probes than either crystallographic site in GdNi{sub 2}. Enthalpy differences between the levels were determined from measurements of temperature dependences of ratios of site fractions. The enthalpy of transfer of In-probes from the Gd- to Ni-sublattice, which is coupled to intrinsic disorder in the compound, was found to be much smaller in the Gd-richer sample than in the Gd-poorer sample. This can be explained by differing temperature dependences of intrinsic defect concentrations at the two compositions. Among those probes that remain within the GdNi{sub 2} phase, there is a temperature dependence of the ratio of site fractions of In-probes on Gd- and Ni-sites. Taking this into account, a macroscopic segregation enthalpy is

Time-intensity curve in the abdominal aorta on dynamic contrast-enhanced MRI with high temporal and spatial resolution. Gd-EOB-DTPA versus Gd-DTPA in vivo

International Nuclear Information System (INIS)

Fujinaga, Yasunari; Tsukahara, Yoshinori; Sugiyama, Yukiko; Kadoya, Masumi; Ueda, Hitoshi; Kitou, Yoshihiro

2013-01-01

The purpose of this study was to evaluate the difference in the time-intensity curves (TICs) of the abdominal aorta on dynamic contrast-enhanced MRI (DCE-MRI) between gadolinium-diethylenetriamine pentaacetic acid (Gd-DTPA) and gadolinium ethoxybenzydiethylenetriamine pentaacetic acid (Gd-EOB-DTPA). Ten healthy volunteers underwent DCE-MRI three times with the following protocol: group A, Gd-DTPA at an injection rate of 3 ml/s; group B, Gd-EOB-DTPA, 3 ml/s; group C, Gd-EOB-DTPA, 1.5 ml/s. Signal intensities (SIs) of the abdominal aorta were measured, and the contrast enhancement ratio (CER) was calculated. Time-to-CER curves were compared among the three groups. The differences in maximum CER (CER max ) and time-to-peak of CER were analyzed. The time-to-CER curve showed a double peak pattern in group A and single-peak pattern in groups B and C. The mean time between the first and the second peak was 6.2 s. The mean CER max of each group was 4.50, 4.52 and 4.27, respectively. In group A, B and C, the mean time-to-peak was 14.6, 10.6 and 12.6 s, respectively. There was a significant difference between group A and B (P<0.01). To set up the optimal protocol for abdominal DCE-MRI, it should be noted that TIC in the Gd-DTPA and Gd-EOB-DTPA group showed different patterns, and a slower injection rate showed a less abrupt SI change in the Gd-EOB-DTPA group than in the Gd-DTPA group. (author)

The Effects of Gd-Free Impurity Phase on the Aging Behavior for the Microwave Surface Resistance of Ag-coated GdBa2Cu3O7-δ at Cryogenic Temperatures

Science.gov (United States)

Lee, Sungho; Yang, Woo Il; Jung, Ho Sang; Oh, Won-Jae; Jang, Jiyeong; Lee, Jae-Hun; Kang, Kihyeok; Moon, Seung-Hyun; Yoo, Sang-Im; Lee, Sang Young

2018-05-01

High-T C GdBa2Cu3O7-δ (GdBCO) superconductor has been popular for making superconductive tapes that have much potential for various fields of large-scale applications. We investigated aging effects on the microwave surface resistance (R S) of Ag-coated GdBCO layer on Hastelloy substrate, so called GdBCO coated conductors (CCs), and Ag-coated GdBCO films on LaAlO3 (LAO) single-crystal substrates at cryogenic temperatures and compared them with each other. Unlike the R S of Ag-coated GdBCO films showing significant degradation in 4 weeks, no significant aging effects were found in our Ag-coated GdBCO CCs aged 85 weeks. The reactive co-evaporation deposition and reaction (RCE-DR) method was used for preparing the Ag-coated GdBCO CCs. Such durability of the Ag-coated GdBCO CCs in terms of the R S could be explained by existence of a protective impurity phase, i.e., Gd-free Ba-Cu-O phase as confirmed by transmission electron microscopy study combined with the energy-dispersive X-ray spectroscopy measurements. Although the scope of this study is limited to the Ag-coated GdBCO CCs prepared by using the RCE-DR method, our results suggest that a solution for preventing the aging effects on transport properties of other kinds of Ag-coated GdBCO CCs could be realized by means of an artificially-grown protective impurity layer.

Behavior of Gd-DTPA in simulated bank filtration

International Nuclear Information System (INIS)

Moeller, Peter; Knappe, Andrea; Dulski, Peter; Pekdeger, Asaf

2011-01-01

Research highlights: → Gd-DTPA and similar products are common pollutants in surface and groundwater and prove to be a reliable monitor for mixing of groundwater with surface water loaded with effluents from sewage treatment plants. → Within a 30 m column filled with Pleistocene sand Gd-DTPA is reduced by 16% only within one month time by transmetallation. → Artificial bank filtration is not very effective in reducing Gd-DTPA in infiltrating water. - Abstract: The behavior of Gd-DTPA during bank filtration was simulated in a 30 m column filled with Pleistocene sand and flushed by surface water from a lakeside in Berlin, Germany. The surface water is about a 1:1 mixture of river water and effluents from a sewage treatment plant. Throughout 34 days this water was continuously spiked with Gd-DTPA at a level of 60 μg/L. The broad plateau of the Gd-DTPA pulse declined by 15.4% within 34 days by transmetallation. Nine percentage of the total decline is caused by Y and rare earth elements; the remaining part is attributed to Cu 2+ which is the most influential metal in surface water. All other metals also contributing to transmetallation are combined with Cu to Cu equivalents because only the rate constant of transmetallation of Cu 2+ is known. The analytical results of the column effluents prove the pseudo-first-order kinetics of transmetallation based on reversible sorption of metals by pools in the column sediment and disprove biodegradation at noticeable levels. The mass ratio of water to tracer is 10 .

Behavior of Gd-DTPA in simulated bank filtration

Energy Technology Data Exchange (ETDEWEB)

Moeller, Peter, E-mail: pemoe@gfz-potsdam.de [Freie Universitaet Berlin, Malteserstr. 74-100, AB Hydrogeologie, 12249 Berlin (Germany)] [Helmholtz Zentrum Potsdam, Deutsches GeoForschungsZentrum, Telegrafenberg, 14473 Potsdam (Germany); Knappe, Andrea [Freie Universitaet Berlin, Malteserstr. 74-100, AB Hydrogeologie, 12249 Berlin (Germany); Dulski, Peter [Helmholtz Zentrum Potsdam, Deutsches GeoForschungsZentrum, Telegrafenberg, 14473 Potsdam (Germany); Pekdeger, Asaf [Freie Universitaet Berlin, Malteserstr. 74-100, AB Hydrogeologie, 12249 Berlin (Germany)

2011-01-15

Research highlights: {yields} Gd-DTPA and similar products are common pollutants in surface and groundwater and prove to be a reliable monitor for mixing of groundwater with surface water loaded with effluents from sewage treatment plants. {yields} Within a 30 m column filled with Pleistocene sand Gd-DTPA is reduced by 16% only within one month time by transmetallation. {yields} Artificial bank filtration is not very effective in reducing Gd-DTPA in infiltrating water. - Abstract: The behavior of Gd-DTPA during bank filtration was simulated in a 30 m column filled with Pleistocene sand and flushed by surface water from a lakeside in Berlin, Germany. The surface water is about a 1:1 mixture of river water and effluents from a sewage treatment plant. Throughout 34 days this water was continuously spiked with Gd-DTPA at a level of 60 {mu}g/L. The broad plateau of the Gd-DTPA pulse declined by 15.4% within 34 days by transmetallation. Nine percentage of the total decline is caused by Y and rare earth elements; the remaining part is attributed to Cu{sup 2+} which is the most influential metal in surface water. All other metals also contributing to transmetallation are combined with Cu to Cu equivalents because only the rate constant of transmetallation of Cu{sup 2+} is known. The analytical results of the column effluents prove the pseudo-first-order kinetics of transmetallation based on reversible sorption of metals by pools in the column sediment and disprove biodegradation at noticeable levels. The mass ratio of water to tracer is <10{sup 10}.

Theranostic Gd(III)-lipid microbubbles for MRI-guided focused ultrasound surgery.

Science.gov (United States)

Feshitan, Jameel A; Vlachos, Fotis; Sirsi, Shashank R; Konofagou, Elisa E; Borden, Mark A

2012-01-01

We have synthesized a biomaterial consisting of Gd(III) ions chelated to lipid-coated, size-selected microbubbles for utility in both magnetic resonance and ultrasound imaging. The macrocyclic ligand DOTA-NHS was bound to PE headgroups on the lipid shell of pre-synthesized microbubbles. Gd(III) was then chelated to DOTA on the microbubble shell. The reaction temperature was optimized to increase the rate of Gd(III) chelation while maintaining microbubble stability. ICP-OES analysis of the microbubbles determined a surface density of 7.5 × 10(5) ± 3.0 × 10(5) Gd(III)/μm(2) after chelation at 50 °C. The Gd(III)-bound microbubbles were found to be echogenic in vivo during high-frequency ultrasound imaging of the mouse kidney. The Gd(III)-bound microbubbles also were characterized by magnetic resonance imaging (MRI) at 9.4 T by a spin-echo technique and, surprisingly, both the longitudinal and transverse proton relaxation rates were found to be roughly equal to that of no-Gd(III) control microbubbles and saline. However, the relaxation rates increased significantly, and in a dose-dependent manner, after sonication was used to fragment the Gd(III)-bound microbubbles into non-gas-containing lipid bilayer remnants. The longitudinal (r(1)) and transverse (r(2)) molar relaxivities were 4.0 ± 0.4 and 120 ± 18 mM(-1)s(-1), respectively, based on Gd(III) content. The Gd(III)-bound microbubbles may find application in the measurement of cavitation events during MRI-guided focused ultrasound therapy and to track the biodistribution of shell remnants. Copyright © 2011 Elsevier Ltd. All rights reserved.

Gd-DTPA L-cystine bisamide copolymers as novel biodegradable macromolecular contrast agents for MR blood pool imaging.

Science.gov (United States)

Kaneshiro, Todd L; Ke, Tianyi; Jeong, Eun-Kee; Parker, Dennis L; Lu, Zheng-Rong

2006-06-01

The purpose of this study was to synthesize biodegradable Gd-DTPA L-cystine bisamide copolymers (GCAC) as safe and effective, macromolecular contrast agents for magnetic resonance imaging (MRI) and to evaluate their biodegradability and efficacy in MR blood pool imaging in an animal model. Three new biodegradable GCAC with different substituents at the cystine bisamide [R = H (GCAC), CH2CH2CH3 (Gd-DTPA L-cystine bispropyl amide copolymers, GCPC), and CH(CH3)2 (Gd-DTPA cystine bisisopropyl copolymers, GCIC)] were prepared by the condensation copolymerization of diethylenetriamine pentaacetic acid (DTPA) dianhydride with cystine bisamide or bisalkyl amides, followed by complexation with gadolinium triacetate. The degradability of the agents was studied in vitro by incubation in 15 microM cysteine and in vivo with Sprague-Dawley rats. The kinetics of in vivo contrast enhancement was investigated in Sprague-Dawley rats on a Siemens Trio 3 T scanner. The apparent molecular weight of the polydisulfide Gd(III) chelates ranged from 22 to 25 kDa. The longitudinal (T1) relaxivities of GCAC, GCPC, and GCIC were 4.37, 5.28, and 5.56 mM(-1) s(-1) at 3 T, respectively. The polymeric ligands and polymeric Gd(III) chelates readily degraded into smaller molecules in incubation with 15 microM cysteine via disulfide-thiol exchange reactions. The in vitro degradation rates of both the polymeric ligands and macromolecular Gd(III) chelates decreased as the steric effect around the disulfide bonds increased. The agents readily degraded in vivo, and the catabolic degradation products were detected in rat urine samples collected after intravenous injection. The agents showed strong contrast enhancement in the blood pool, major organs, and tissues at a dose of 0.1 mmol Gd/kg. The difference of their in vitro degradability did not significantly alter the kinetics of in vivo contrast enhancement of the agents. These novel GCAC are promising contrast agents for cardiovascular and tumor MRI

Enhanced room temperature multiferroicity in Gd doped BFO

CSIR Research Space (South Africa)

Pradhan, SK

2009-01-01

Full Text Available deficient Gd doped multiferroic BFO system. At particular doping level of Gd, this bulk ceramics showed spectacular M~H behavior at room temperature which is likely to open a new avenue for the potential applications in information storing technology as well...

Magnetic transition in Co/(Gd-Co) multilayers

International Nuclear Information System (INIS)

Svalov, A.V.; Fernandez, A.; Barandiaran, J.M.; Vas'kovskiy, V.O.; Orue, I.; Tejedor, M.; Kurlyandskaya, G.V.

2008-01-01

[Co/Gd 0.36 Co 0.64 ] 4 /Co multilayers with Co termination layer have been prepared by rf sputtering. They form macroscopic ferrimagnets with a compensation temperature (T comp ) determined by the thickness ratio of the layers. In low fields the magnetization of Co and Gd-Co layers are along the axis of the applied field. Increasing field makes the moments of both the Co and Gd-Co layers deviate from the axis of the field giving rise to a transition into a twisted state. These magnetic transitions were studied by vibrating sample magnetometer (VSM), magneto-optic Kerr effect and magnetoresistance measurements at various temperatures. The nucleation and evolution of surface- and bulk-twisted magnetic states were also observed in these multilayers

Simulations of Lithium-Based Neutron Coincidence Counter for Gd-Loaded Fuel

Energy Technology Data Exchange (ETDEWEB)

Cowles, Christian C. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Kouzes, Richard T. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Siciliano, Edward R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

2014-10-01

The Department of Energy Office of Nuclear Safeguards and Security (NA-241) is supporting the project Lithium-Based Alternative Neutron Detection Technology Coincidence Counting for Gd-loaded Fuels at Pacific Northwest National Laboratory for the development of a lithium-based neutron coincidence counter for nondestructively assaying Gd loaded nuclear fuel. This report provides results from MCNP simulations of a lithium-based coincidence counter for the possible measurement of Gd-loaded nuclear fuel. A comparison of lithium-based simulations and UNCL-II simulations with and without Gd loaded fuel is provided. A lithium-based model, referred to as PLNS3A-R1, showed strong promise for assaying Gd loaded fuel.

Value of Gd-EOB-DTPA-enhanced MRI in assessing liver function

Directory of Open Access Journals (Sweden)

WANG Lili

2015-05-01

Full Text Available ObjectiveTo explore the value of magnetic resonance imaging (MRI specifically enhanced with gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid (Gd-EOB-DTPA in assessing the liver function in general population. MethodsUpper abdominal MRI images and Gd-EOB-DTPA-enhanced images, as well as some clinical information, were collected from 41 cases meeting the inclusion and exclusion criteria. Taking the spleen as the control organ, liver-spleen signal intensity contrast (SIliver/spleen and relative liver enhancement (RLE were calculated at 10 min and 20 min after injecting Gd-EOB-DTPA. Differences were evaluated using the independent-samples t-test or Mann-Whitney U test. Corrections were analyzed via Spearman’s rank correlation. ResultsBoth SIliver/spleen at 10 min and 20 min after injection of contrast agent were correlated with Child classification (P＜0.05. SIliver/spleen at 20 min had a greater correlation coefficient (r=-0.526 than that at 10 min. The SIliver/spleen with plain scan had no significant correlation with Child classification (P＞0.05. RLE at 20 min, but not at 10 min, was correlated with Child classification (r=-0.362, P=0049. Between the cirrhotic and non-cirrhotic groups, SIliver/spleen showed no significant difference (P＞0.05. However, SIliver/spleen at 10 min and 20 min, as well as RLE20 min, showed significant differences between the cirrhotic and non-cirrhotic groups (P＜0.05. SIliver/spleen at 20 min also exhibited a significant difference between the elevated and normal ALT and TBil groups (both P＜0.05. ConclusionGd-EOB-DTPA-enhanced MRI can monitor liver function changes, and SIliver/spleen at 20 min may have an important value in assessing the liver function in general population.

Characterization of InGaGdN layers prepared by molecular beam epitaxy

Energy Technology Data Exchange (ETDEWEB)

Tawil, Siti Nooraya Mohd [Institute of Scientific and Industrial Research, Osaka University, 8-1 Mihagaoka, Ibaraki, 567-0047 Osaka (Japan); Faculty of Electrical and Electronic Engineering, Tun Hussein Onn University of Malaysia, 86400 Batu Pahat Johor (Malaysia); Kakimi, Rina; Krishnamurthy, Daivasigamani; Emura, Shuichi; Tambo, Hiroyuki; Hasegawa, Shigehiko; Asahi, Hajime [Institute of Scientific and Industrial Research, Osaka University, 8-1 Mihagaoka, Ibaraki, 567-0047 Osaka (Japan)

2010-11-15

Gd-doped InGaN layers were prepared by plasma-assisted molecular-beam epitaxy in search of new functional diluted magnetic semiconductors for their potential use in spintronics. The local structure around the Gd atoms was examined by the Gd L{sub III}-edge of X-ray absorption fine structure. It was found that the majority of Gd atoms substitutionally occupied the cation sites in the InGaGdN layers. Clear hysteresis and saturation magnetization were observed from the magnetization versus field curves examined by means of a superconducting quantum interference device magnetometer at low and room temperatures. In addition, the incorporation of extra shallow donors by co-doping InGaN with both Gd and Si showed higher magnetization than the undoped InGaGdN. (copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Gd(III)-DOTA-modified sonosensitive liposomes for ultrasound-triggered release and MR imaging

Science.gov (United States)

Jung, Suk Hyun; Na, Kyunga; Lee, Seul A.; Cho, Sun Hang; Seong, Hasoo; Shin, Byung Cheol

2012-08-01

Ultrasound-sensitive (sonosensitive) liposomes for tumor targeting have been studied in order to increase the antitumor efficacy of drugs and decrease the associated severe side effects. Liposomal contrast agents having Gd(III) are known as a nano-contrast agent system for the efficient and selective delivery of contrast agents into pathological sites. The objective of this study was to prepare Gd(III)-DOTA-modified sonosensitive liposomes (GdSL), which could deliver a model drug, doxorubicin (DOX), to a specific site and, at the same time, be capable of magnetic resonance (MR) imaging. The GdSL was prepared using synthesized Gd(III)-DOTA-1,2-distearoyl- sn-glycero-3-phosphoethanolamine lipid. Sonosensitivity of GdSL to 20-kHz ultrasound induced 33% to 40% of DOX release. The relaxivities ( r 1) of GdSL were 6.6 to 7.8 mM-1 s-1, which were higher than that of MR-bester®. Intracellular uptake properties of GdSL were evaluated according to the intensity of ultrasound. Intracellular uptake of DOX for ultrasound-triggered GdSL was higher than that for non-ultrasound-triggered GdSL. The results of our study suggest that the paramagnetic and sonosensitive liposomes, GdSL, may provide a versatile platform for molecular imaging and targeted drug delivery.

Operation and maintenance techniques of 1 ton bucket elevator in IMEF

International Nuclear Information System (INIS)

Soong, Woong Sup

1999-04-01

IMEF pool is used as a pathway between pool and hot cell in order to transfer (incoming and outgoing) irradiated materials. Transfer is performed by 1 ton bucket elevator which is moved inside the rectangular tube installed between pool and M1 hot cell. Allowable load capacity is 1 ton of the bucket elevator and its size is 25 X 25 X 150 cm. Bucket is driven by chain system which is moved up and down through the guide rail. Guide rail is installed in rectangular tube that is tilted about 63 degree. Chain which is moved by using the roller sliding method is driven by sprocket wheel being rotated by the shaft and the shaft is driven by gear reducing motor. In this report operation and maintenance techniques of 1 ton bucket elevator in IMEF are described in detail. (Author). 8 refs., 14 tabs., 6 figs

Operation and maintenance techniques of 1 ton bucket elevator in IMEF

Energy Technology Data Exchange (ETDEWEB)

Soong, Woong Sup

1999-04-01

IMEF pool is used as a pathway between pool and hot cell in order to transfer (incoming and outgoing) irradiated materials. Transfer is performed by 1 ton bucket elevator which is moved inside the rectangular tube installed between pool and M1 hot cell. Allowable load capacity is 1 ton of the bucket elevator and its size is 25 X 25 X 150 cm. Bucket is driven by chain system which is moved up and down through the guide rail. Guide rail is installed in rectangular tube that is tilted about 63 degree. Chain which is moved by using the roller sliding method is driven by sprocket wheel being rotated by the shaft and the shaft is driven by gear reducing motor. In this report operation and maintenance techniques of 1 ton bucket elevator in IMEF are described in detail. (Author). 8 refs., 14 tabs., 6 figs.

SIMS imaging of gadolinium isotopes in tissue from Nephrogenic Systemic Fibrosis patients: Release of free Gd from magnetic resonance imaging (MRI) contrast agents

Energy Technology Data Exchange (ETDEWEB)

Abraham, Jerrold L. [Department of Pathology, SUNY Upstate Medical University, Syracuse, New York (United States); Chandra, Subhash [Cornell SIMS Laboratory, Department of Earth and Atmospheric Sciences, Cornell University, Ithaca, NY 14853 (United States)], E-mail: sc40@cornell.edu; Thakral, Charu [Department of Pathology, SUNY Upstate Medical University, Syracuse, New York (United States); Abraham, Joshua M. [Cornell SIMS Laboratory, Department of Earth and Atmospheric Sciences, Cornell University, Ithaca, NY 14853 (United States)

2008-12-15

Recently, Gd-based magnetic resonance imaging (MRI) contrast agents (GBMCA) have been linked to a new disease, Nephrogenic Systemic Fibrosis (NSF), with skin and systemic toxicity and death in certain patients with renal failure. Due to widespread use of GBMCA in diagnostic MRI, it is essential to study their excretion, metabolism, and target sites in cells and tissues. A CAMECA IMS-3f SIMS ion microscope and scanning electron microscopy (SEM) with energy dispersive X-ray spectroscopy (EDS) were used for imaging Gd isotopes in relation to calcium distributions in histologic sections of human tissues. SIMS imaging revealed two types of Gd localization in skin biopsies of patients who received GBMCA. The Gd was present in micrometer size deposits in association with calcium, and in detectable amounts in a more diffuse cellular distribution. Only the Gd-containing deposits associated with Ca and P were detectable using SEM/EDS. As only insoluble deposits remain in the biopsy tissues after aqueous and organic solvent processing of the tissue, our observations support release of free Gd from the GBMCA and selective localization of insoluble Gd in the target tissue from patients with NSF. This study opens new novel applications of SIMS for characterization of the safety of GBMCA.

Superconductivity and magnetism in Ir-doped GdFeAsO

International Nuclear Information System (INIS)

Cui, Y.J.; Chen, Y.L.; Cheng, C.H.; Yang, Y.; Jiang, J.; Wang, Y.Z.; Zhang, Y.; Zhao, Y.

2010-01-01

The 5d-transition metal, Ir has successfully been doped at Fe site and induced superconductivity in GdFeAsO at T c = 18.9 K and ∼20 atom%. The Ir-doping shortened the c-axis length and stretched the a-axis one, which led to enhance the coupling between the FeAs- and SmO-layer, and to weaken the bonding between Fe and As atom. Paramagnetism was observed in all of the samples, which was resulted from the magnetic Gd ion as in the F-doped GdFeAsO. An upper critical field of GdFe 0.8 Ir 0.2 AsO was extrapolated to around 24 T, much smaller than that of F-doped GdFeAsO owing to a relatively low T c and small value of dH c2 /dT.

Thermodynamic assessments of the Ag-Gd and Ag-Nd systems

International Nuclear Information System (INIS)

Wang, S.L.; Wang, C.P.; Liu, X.J.; Ishida, K.

2009-01-01

The phase diagrams and thermodynamic properties in the Ag-Re (Re: Gd, Nd) binary systems have been assessed by using the CALPHAD (Calculation of Phase Diagrams) method on the basis of the experimental data including the thermodynamic properties and phase equilibria. The Gibbs free energies of the liquid, bcc, fcc, dhcp and hcp phases were described by the subregular solution model with the Redlich-Kister equation, and those of the intermetallic compounds (Ag 51 Gd 14 , Ag 2 Gd, AgGd, Ag 51 Nd 14 , αAg 2 Nd, βAg 2 Nd and AgNd phases) in these two binary systems were described by the sublattice model. The thermodynamic parameters of each phase in the Ag-Re (Re: Gd, Nd) binary systems were obtained, and an agreement between the calculated results and experimental data was obtained in each binary system.

Nouvelles Techniques d'Intervention sur la Corrosion des Armatures du Béton Armé

CERN Document Server

Colloca, C

1999-01-01

Les principaux dégâts constatés dans les armatures passives du béton armé sont la corrosion généralisée et la corrosion locale. Ces dégradations sont provoquées soit par la carbonatation du béton soit par le contact avec l'eau pure ou l'eau chargée de chlorures pénétrant dans les pores et dans les fissures de surface. Ce document présente de nouvelles techniques d'intervention, fondées sur d'anciens principes, introduites pour le traitement électrochimique des zones altérées liées aux différentes conditions. La réalcalinisation (dans le cas de béton carbonaté) permet d'augmenter le pH du béton et de rétablir un niveau de basicité garantissant la passivation de l'armature. La désalification (dans le cas de béton entamé par les chlorures) provoque l'élimination des ions chlorure à travers la surface du béton. Les avantages de ces traitements, par rapport aux anciennes techniques, sont appréciables si l'on considère la durée d'exécution et leur coût moins élevé.

The isothermal section at 500 deg. C of the Gd-Tb-Ga ternary system

International Nuclear Information System (INIS)

Li, J.Q.; Jian, Y.X.; Ao, W.Q.; Zhuang, Y.H.; He, W.

2006-01-01

Phase equilibria in the Gd-Tb-Ga ternary system at 500 deg. C were investigated by X-ray powder diffraction and differential scanning calorimetry. The binary compounds, Gd 5 Ga 3 , Gd 3 Ga 2 , GdGa, GdGa 2 , Tb 5 Ga 3 , TbGa, TbGa 2 and TbGa 3 have been confirmed at 500 deg. C. No ternary compound was found in this system. The isothermal section of this system at 500 deg. C was constructed. It is composed of 7 single-phase regions, 8 two-phase regions and 2 three-phase regions. Four ternary continuous solid solutions (Gd, Tb), (Gd, Tb) 5 Ga 3 , (Gd, Tb)Ga, (Gd, Tb)Ga 2 were formed in this isothermal section. The maximum solid solubilities of Ga in (Gd, Tb) at 500 deg. C is 5.0 at.%. The homogeneity range of (Gd, Tb)Ga 2 is from 20 to 33.3 at.% Ga in Gd-Ga side but limited in Tb-Ga side. The solid solubilities of Ga in the other phases cannot be detected. The Curie temperatures of the Gd 0.6 Tb 0.4-x Ga x alloys increase from 270 to 298 K as x increases from 0 to 0.03

Charge compensation mechanisms in U{sub 1-x}Gd{sub x}O{sub 2} and Th{sub 1-x}Gd{sub x}O{sub 2-x/2} studied by X-ray Absorption Spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Bès, R., E-mail: rene.bes@aalto.fi [Department of Applied Physics, Aalto University, P.O. Box 14100, FI-00076 Aalto (Finland); Pakarinen, J.; Baena, A. [Belgian Nuclear Research Centre (SCK-CEN), Institute for Nuclear Materials Science, Boeretang 200, B-2400 Mol (Belgium); Conradson, S. [Synchrotron SOLEIL, Ligne de Lumière MARS, L' Orme des Merisiers, Saint Aubin, BP 48, F-91192 Gif-sur-Yvette Cedex (France); Verwerft, M. [Belgian Nuclear Research Centre (SCK-CEN), Institute for Nuclear Materials Science, Boeretang 200, B-2400 Mol (Belgium); Tuomisto, F. [Department of Applied Physics, Aalto University, P.O. Box 14100, FI-00076 Aalto (Finland)

2017-06-15

The charge compensation mechanisms in U{sub 1-x}Gd{sub x}O{sub 2} and Th{sub 1-x}Gd{sub x}O{sub 2-x/2} have been systematically studied using X-ray Absorption Spectroscopy (XAS) upon gradually increasing the Gd content. Gd doped nuclear fuels are widely used for optimizing the fresh core neutronics, yet when Gd{sup 3+} is substituted into U{sup 4+} or Th{sup 4+} lattice position in UO{sub 2} or ThO{sub 2}, respectively, charge must be compensated for charge neutrality. In U{sub 1-x}Gd{sub x}O{sub 2} the general hypothesis has been that the U{sup 4+} will oxidise to U{sup 5+}/U{sup 6+} while in Th{sub 1-x}Gd{sub x}O{sub 2-x/2} the fixed Th{sup 4+} valence requires generation of O vacancies. Our XAS results for a series of technologically relevant Gd contents (x = 0.04 to 0.14) in U{sub 1-x}Gd{sub x}O{sub 2} clearly demonstrate that upon increasing the Gd content U{sup 5+} is formed inducing slight increase in the U coordination number and contraction for the U-O distances while the Gd local environment remains virtually unchanged. For the Th{sub 1-x}Gd{sub x}O{sub 2-x/2} larger Gd fractions were applied (x = 0.10 to 0.34). Nonetheless, both Gd and Th local environments show changes upon increasing the Gd content; the average Gd-O and Th-O distances decrease gradually and the Gd and Th coordination numbers follow the expected trend considering the O vacancy formation to obtain charge neutrality. Finally, comparison to Gd{sub 2}O{sub 3} allowed us to propose that one of the Gd L{sub 3}-edge XANES resonance features is directly connected to the generation of O vacancies.

Positron annihilation study on the superconductivity of Gd-doped YBCO system

International Nuclear Information System (INIS)

Chen Zhenping; Su Yuling; Xue Yuncai; Liu Haizeng; Gong Shicheng; Zhao Jingxun; Li Xigui

2006-01-01

To make clear the influence of magnetic rare-earth ion Gd 3+ doping in the Y site on crystal structure and localized electron structure of YBCO system, the Gd-doped Y 1-x Gd x Ba 2 Cu 3 O 7-δ (x=0-1.0) systems were studied systematically by the positron annihilation technique and X-ray diffraction (XRD). The XRD analysis reveals that Gd 3+ with bigger radius doping in Y site makes the crystal parameters and crystal volume increase, while all the samples remain the single orthorhombic phase as YBa 2 Cu 3 O 7-δ (YBCO) system does. The temperature dependence of resistance measurement shows that T c is above 90 K for all samples, and T c increases with increasing Gd 3+ content. The positron experiment indicates that the localized electronic density n e decreases with increasing Gd 3+ content. (authors)

MR cisternography after intrathecal Gd-DTPA application

International Nuclear Information System (INIS)

Reiche, Werner; Komenda, Yvonne; Steudel, Wolf-Ingo; Schick, Bernhard; Grunwald, Iris; Reith, Wolfgang

2002-01-01

The purpose of this study was to establish and to evaluate MR cisternography after intrathecal Gd-DTPA administration to detect rhinobasal cerebrospinal fluid (CSF) fistulae in patients with suspected CSF rhinorrhoea. Ten patients with suspected CSF rhinorrhoea were examined. The MR cisternography included the following investigation steps: acquisition of nonenhanced fat-suppressed T1-weighted spin-echo (SE) scans of the skull base and the paranasal sinuses, lumbar puncture with administration of 1 ml Gd-DTPA solute with 4 ml NaCl and performance of MR cisternography with the same fat-suppressed T1-weighted sequences as used initially. In 10 patients with suspected CSF rhinorrhoea Gd-DTPA enhanced MR cisternography detected 5 CSF fistulae. In 3 of 5 CSF leaks were located in the cribriform plate and in 2 of 5 sphenoidal. Whereas 4 of these depicted leaks were confirmed surgically, in 1 case the CSF fistula closed spontaneously. In another case, CSF leakage after severe head injury was clinically highly suspected but ceased prior to MR cisternography with inability to detect the temporary fistula. In the remaining 4 patients with serous rhinorrhoea MR cisternography did not provide any evidences for CSF fistulae. Intrathecal Gd-DTPA injection was tolerated excellently. Clinical and EEG examinations showed no gross behavioural or neurological disturbances and no seizure activity, respectively. The MR cisternography after intrathecal administration of Gd-DTPA represents a safe, promising and minimally invasive method for detection of CSF fistulae. This MR investigation provides excellent depiction of CSF spaces and pinpoints CSF fistulae. (orig.)

Effect of rare-earth composition on microstructure and pinning properties of Zr-doped (Gd, Y)Ba{sub 2}Cu{sub 3}O{subx} superconducting tapes.

Energy Technology Data Exchange (ETDEWEB)

Selvamanickam, V.; Chen, Y.; Zhang, Y.; Guevara, A.; Shi, T.; Yao, Y.; Majkic, G.; Lei, C.; Galtsyan, E.; Miller, D. J. (Materials Science Division); (Univ. Houston); (SuperPower Inc.)

2012-01-01

The effect of changing Gd + Y content from 1.2 to 1.6 in the precursor of (Gd,Y)Ba{sub 2}Cu{sub 3}O{sub 7} superconducting thin film tapes made by metal organic chemical vapor deposition (MOCVD) at a constant Gd:Y ratio and a fixed Zr content of 7.5% has been studied. The influence of changing the Gd:Y ratio from Gd = 0 to Y= 0 in 0.2 mol steps at a constant Gd + Y content of 1.2 in the precursor has also been investigated at a fixed Zr content of 7.5%. The critical current of these films is found to vary significantly as a function of rare-earth content as well as a function of rare-earth type. Even for a fixed Zr content, it is found that the critical current in the orientation of magnetic field parallel to the a-b plane and that in the orientation of field perpendicular to the a-b plane can be systematically varied with changing Gd + Y content as well as with changing Gd:Y ratio. The nanoscale defect structures along the a-b plane and along the c-axis are found to be sensitive to these changes in rare-earth content and type.

Usefulness of fat-suppressed Gd-enhanced MR imaging of tongue cancer

International Nuclear Information System (INIS)

Murakami, Shumei; Fuchihata, Hajime; Yoon, Sukja; Furukawa, Souhei; Kawai, Tadahiko; Kishino, Mitsunobu

1999-01-01

To evaluate the usefulness of the fat suppression technique for magnetic resonance imaging of oral tongue cancer. One hundred and fourteen patients underwent both magnetic resonance imaging (MRI) and computed tomography (CT). All patients were clinically diagnosed as having oral tongue cancer shown to be squamous cell carcinoma histopathologically. We used two types of CT and six types of MRI scanning: plain CT, contrast enhanced CT, conventional T1w, conventional PDw, conventional T2w, fat-suppressed (FATS) T1w, Gd-enhanced conventional T1w, and Gd-enhanced FATS T1w images. The focus of our study was Gd-enhanced FATS T1w imaging. Tumor detection rates were as follows: Gd-enhanced FATS T1w MRI, 86.8%; conventional T2w MRI, 71.9%; conventional PDw MRI, 65.8%; Gd-enhanced conventional T1w MRI, 47.4%; contrast enhanced CT, 36.8%; T1w MRI, 20.2%; CT, 10.5%. There were 59 cases in which tumors were detected by Gd-enhanced FATS T1w MRI but not detected by contrast enhanced CT. Gd-enhanced FATS T1w MRI was the best for the tumor detection and Gd-enhanced conventional T1w MRI was not useful in the diagnosis of the tongue cancer. CT imaging must not be the first choice for tumor detection in tongue cancer patients. (author)

Gd-DTPA-enhanced dynamic MR imaging

International Nuclear Information System (INIS)

Frank, J.A.; Choyke, P.L.; Carvlin, M.; Inscoe, S.; Austin, H.; Dwyer, A.J.; Girton, M.; Black, J.

1988-01-01

This paper describes dynamic enhanced renal MR imaging, a new method of identifying specific derangements in renal function. Various diuretics were employed in 45 animal experiments to demonstrate the effects on the normal renal enhancement pattern (EP) after Gd-DTPA. Since different diuretics, osmotic (O), carbonic anhydrase (CA), and loop (L), are active at different sites, specific EP alterations are observed. Imaging was performed with 32 5.1-second sequential gradient recalled acquisition in a steady state images following a bolus of Gd-DTPA

GROWTH AND YIELD OF ORGANIC RICE WITH COW MANURE APPLICATION IN THE FIRST CROPPING SEASON

Directory of Open Access Journals (Sweden)

Wahyu Arif Sudarsono

2014-02-01

Full Text Available The study was addressed to investigating the effect of cow manure application rate on organic rice growth and yield in the first cropping season. The study was conducted from January to April 2012 in Blora, Central Java, Indonesia. The experiment was arranged in Randomized Complete Block Design, consisting of four treatments and four replications. There were two types of control treatments i.e. organic fertilizer treatments (statistically analyzed and conventional fertilizer (not statistically analyzed. The treatments were corn biomass, corn biomass+cow manure (7.5 tons ha-1, corn biomass+cow manure (10 tons ha-1 and cow manure (10 tons ha-1 with square spacing of 20 cm x 20 cm. The organic control treatments were corn biomass+sheep manure (7.5 tons ha-1 with spacing of 20 cm x 20 cm and corn biomass+cow manure (7.5 tons ha-1 with double-row spacing of 40 cm x 25 cm x 15 cm. For every treatment, the rate of corn biomass was 3 tons ha-1. All organic treatments were also added with 3 tons rice hull ash ha-1. The application of cow manure (10 tons ha-1 with square spacing or corn biomass+cow manure (7.5 tons ha-1 with double-row spacing resulted in better performance than those of other treatments.

Synergistic effect of Al and Gd on enhancement of mechanical properties of magnesium alloys

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Bita Pourbahari

2017-04-01

Full Text Available The effect of Gd/Al ratio on the properties of as-cast Mg-Gd-Al-Zn alloys was investigated by changing the chemical composition from that of AZ61 to GZ61. At the ratio of 1, the Al2Gd phase becomes predominant and Mg17Al12 is hardly seen in the microstructure. As a potent inoculant, the Al2Gd phase resulted in intense grain refinement and enhancement of strength, ductility and toughness. For instance, the tensile strength and elongation to failure of Mg-3Gd-3Al-1Zn alloy were enhanced by ~4% and 180% compared with those of AZ61 alloy, respectively. However, at high Gd/Al ratios, the Al2Gd phase was replaced by (Mg,Al3Gd and Mg5Gd phases and very large grain sizes were achieved, which led to poor tensile properties and the appearance of cleavage facets on the fracture surfaces. Therefore, it can be deduced that the presence of Gd and Al, in appropriate amounts to reach Gd/Al ratio of ~ 1, is required for the achievement of grain refinement, good ductility, high strength, and the appearance of ductile fracture surfaces in the Mg-Gd-Al-Zn system. Conclusively, the Mg-Gd-Al-Zn alloys can be considered as a new class of structural magnesium alloy and it is superior to both AZ (Mg-Al-Zn and GZ (Mg-Gd-Zn series of alloys.

Superconductivity and magnetism in Ir-doped GdFeAsO

Energy Technology Data Exchange (ETDEWEB)

Cui, Y.J.; Chen, Y.L. [Key Laboratory of Magnetic Levitation and Maglev Trains (Ministry of Education of China), Superconductivity R and D Center (SRDC), Mail Stop 165, Southwest Jiaotong University, Chengdu, Sichuan 610031 (China); Cheng, C.H. [School of Materials Science and Engineering, University of New South Wales, Sydney 2052 NSW (Australia); Yang, Y.; Jiang, J.; Wang, Y.Z.; Zhang, Y. [Key Laboratory of Magnetic Levitation and Maglev Trains (Ministry of Education of China), Superconductivity R and D Center (SRDC), Mail Stop 165, Southwest Jiaotong University, Chengdu, Sichuan 610031 (China); Zhao, Y., E-mail: yzhao@swjtu.edu.c [Key Laboratory of Magnetic Levitation and Maglev Trains (Ministry of Education of China), Superconductivity R and D Center (SRDC), Mail Stop 165, Southwest Jiaotong University, Chengdu, Sichuan 610031 (China); School of Materials Science and Engineering, University of New South Wales, Sydney 2052 NSW (Australia)

2010-11-01

The 5d-transition metal, Ir has successfully been doped at Fe site and induced superconductivity in GdFeAsO at T{sub c} = 18.9 K and {approx}20 atom%. The Ir-doping shortened the c-axis length and stretched the a-axis one, which led to enhance the coupling between the FeAs- and SmO-layer, and to weaken the bonding between Fe and As atom. Paramagnetism was observed in all of the samples, which was resulted from the magnetic Gd ion as in the F-doped GdFeAsO. An upper critical field of GdFe{sub 0.8}Ir{sub 0.2}AsO was extrapolated to around 24 T, much smaller than that of F-doped GdFeAsO owing to a relatively low T{sub c} and small value of dH{sub c2}/dT.

Antiferromagnetic ordering in GdRhIn{sub 5}

Energy Technology Data Exchange (ETDEWEB)

Latka, K.; Rams, M. [Marian Smoluchowski Inst. of Physics, Jagiellonian Univ., Krakow (Poland); Kmiec, R.; Pacyna, A.W. [Henryk Niewodniczanski Inst. of Nuclear Physics, Polish Academy of Sciences, Krakow (Poland); Zaremba, V.I. [Inorganic Chemistry Dept., Ivan Franko National Univ. of Lviv, Lviv (Ukraine); Inst. fuer Anorganische und Analytische Chemie, Westfaelische Wilhelms-Univ. Muenster (Germany); Poettgen, R. [Inst. fuer Anorganische und Analytische Chemie, Westfaelische Wilhelms-Univ. Muenster (Germany)

2004-09-01

A polycrystalline sample of tetragonal GdRhIn{sub 5} (HoCoGa{sub 5} type, space group P4/mmm) was obtained by induction melting of the elements in a glassy carbon crucible in a water-cooled sample chamber and subsequent annealing at 670 K. X-ray powder data yielded the cell parameters a = 460.65(7), c = 743.52(12) pm. The magnetic and electronic properties of GdRhIn{sub 5} have been studied by magnetic susceptibility, electrical resistivity, and {sup 155}Gd Moessbauer spectroscopic measurements. Antiferromagnetic ordering is detected at 41.0(2) K. The results are discussed using a simple molecular field approximation. (orig.)

Influences of Gd on the microstructure and strength of Mg-4.5Zn alloy

International Nuclear Information System (INIS)

Yang Jie; Xiao Wenlong; Wang Lidong; Wu Yaoming; Wang Limin; Zhang Hongjie

2008-01-01

Microstructure and mechanical properties of peak-aged Mg-4.5Zn-xGd (x 0, 0.5, 1.0 and 1.5 wt.%) alloys have been investigated. The results showed that the grain size of the alloys was refined gradually with increasing Gd. Mg 5 Gd and Mg 3 Gd 2 Zn 3 phases were found in the Gd-containing alloys. The strengths were greatly improved with Gd additions, and the highest strength level was obtained in the Mg-4.5Zn-1.5Gd alloy, in which the ultimate tensile strength and yield strength were 231 MPa and 113 MPa, respectively. Through comparing with the Mg-4.5Zn alloy, the increments of ultimate tensile strength and yield strength were 22 MPa and 56 MPa, respectively. The improved strength was mainly correlated to the grain refining effect, the strengthening effect of the Mg 5 Gd and Mg 3 Gd 2 Zn 3 phases and also the hardening effect of the solutioned Gd atoms

Etude comparative de la cinétique de la réaction d’hydratation des bétons autoplaçants et des bétons vibrés

Directory of Open Access Journals (Sweden)

Ahmed Gargouri

2014-04-01

En effet, la nature exothermique de la réaction chimique du ciment peut induire des déformations de dilatation et de contraction. Par ailleurs, la dépression capillaire crée par la consommation d’eau due à l’hydratation du ciment entraine un retrait de dessiccation. Ces déformations peuvent entrainer des micros fissurations pouvant affecter la durabilité de l’ouvrage à long terme surtout pour les ouvrages épais. D’où l’importance d’étudier la cinétique d’hydratation de ses bétons non conventionnels et de les comparer à celle des bétons vibrés traditionnels. L’évolution de la température adiabatique ainsi que la variation en fonction du temps du degré d’hydratation sont déterminées pour le béton autoplaçant et le béton vibré. L’analyse des résultats expérimentaux obtenus montre que le changement de composition modifie considérablement la cinétique de la réaction d’hydratation.

Structure evolution and magnetic properties of annealed nanoscale Gd/Ti multilayers

Directory of Open Access Journals (Sweden)

Larrañaga A.

2013-01-01

Full Text Available The structure and magnetic properties were comparatively analyzed for [Gd/Ti]n multilayers with Gd layer thickness of 1.5 to 12 nm. Multilayers were deposited by sputtering technique at room temperature and annealed for the temperatures up to 400 ºC. It was observed that the samples are highly textured in a different way depending on the Gd layer thickness and annealing temperature. It was found that the heat treatment practically does not change the Gd grain size. The lattice parameters obtained from X-ray results change significantly only for [Gd(1.5nm/Ti]50 multilayers, but their values remain higher than for the bulk Gd. The initial slope of the temperature dependence of magnetization near Curie temperature becomes steeper and Curie temperature increases upon annealing. Curie temperature variation can be understood by taking into account both relaxation of the lattice imperfections and change in lattice constants.

Facile Synthesis of Gd-Functionalized Gold Nanoclusters as Potential MRI/CT Contrast Agents

Directory of Open Access Journals (Sweden)

Wenjun Le

2016-04-01

Full Text Available Multi-modal imaging plays a key role in the earlier detection of disease. In this work, a facile bioinspired method was developed to synthesize Gd-functionalized gold nanoclusters (Gd-Au NCs. The Gd-Au NCs exhibit a uniform size, with an average size of 5.6 nm in dynamic light scattering (DLS, which is a bit bigger than gold clusters (3.74 nm, DLS, while the fluorescent properties of Gd-Au NCs are almost the same as that of Au NCs. Moreover, the Gd-Au NCs exhibit a high longitudinal relaxivity value (r1 of 22.111 s−1 per mM of Gd in phosphate-buffered saline (PBS, which is six times higher than that of commercial Magnevist (A complex of gadolinium with a chelating agent, diethylenetriamine penta-acetic acid, Gd-DTPA, r1 = 3.56 mM−1·s−1. Besides, as evaluated by nano single photon emission computed tomography (SPECT and computed tomography (CT the Gd-Au NCs have a potential application as CT contrast agents because of the Au element. Finally, the Gd-Au NCs show little cytotoxicity, even when the Au concentration is up to 250 μM. Thus, the Gd-Au NCs can act as multi-modal imaging contrast agents.

Magnetocaloric effect in gadolinium-oxalate framework Gd2(C2O4)3(H2O)6⋅(0⋅6H2O)

International Nuclear Information System (INIS)

Sibille, Romain; Didelot, Emilie; Mazet, Thomas; Malaman, Bernard; François, Michel

2014-01-01

Magnetic refrigerants incorporating Gd 3+ ions and light organic ligands offer a good balance between isolation of the magnetic centers and their density. We synthesized the framework material Gd 2 (C 2 O 4 ) 3 (H 2 O) 6 ⋅0.6H 2 O by a hydrothermal route and characterized its structure. The honeycomb lattice of Gd 3+ ions interlinked by oxalate ligands in the (a,c) plane ensures their decoupling in terms of magnetic exchange interactions. This is corroborated by magnetic measurements indicating negligible interactions between the Gd 3+ ions in this material. The magnetocaloric effect was evaluated from isothermal magnetization measurements. The maximum entropy change −ΔS M max reaches 75.9 mJ cm −3 K −1 (around 2 K) for a moderate field change (2 T)

Magnetic and transport properties of sputtered Gd-Y multilayers

International Nuclear Information System (INIS)

Freitas, P.P.; From, M.; Melo, L.V.

1991-01-01

Gd-Y-Gd multilayers were prepared that show a magnetoresistance enhancement for an Y layer separation of 30 A. This magnetoresistance enhancement is an interface effect and occurs in samples where some degree of antiferromagnetic coupling is present

Polymorphous GdScO3 as high permittivity dielectric

International Nuclear Information System (INIS)

Schäfer, A.; Rahmanizadeh, K.; Bihlmayer, G.; Luysberg, M.; Wendt, F.; Besmehn, A.; Fox, A.

2015-01-01

Four different polymorphs of GdScO 3 are assessed theoretically and experimentally with respect to their suitability as a dielectric. The calculations carried out by density functional theory reveal lattice constants, band gaps and the energies of formation of three crystal phases. Experimentally all three crystal phases and the amorphous phase can be realized as thin films by pulsed laser deposition using various growth templates. Their respective crystal structures are confirmed by X-ray diffraction and transmission electron microscopy reflecting the calculated lattice constants. X-ray photoelectron spectroscopy unveils the band gaps of the different polymorphs of GdScO 3 which are above 5 eV for all films demonstrating good insulating properties. From capacitance voltage measurements, high permittivities of up to 27 for hexagonal GdScO 3 are deduced. - Highlights: • Different epitaxial polymorph phases of GdScO 3 were grown by pulsed laser deposition. • The cubic phase of GdScO 3 is reported for the first time. • All phases are proven to be useful for the use in silicon based and III–V based microelectronic devices.

Large magnetocaloric effect of GdNiAl2 compound

International Nuclear Information System (INIS)

Dembele, S.N.; Ma, Z.; Shang, Y.F.; Fu, H.; Balfour, E.A.; Hadimani, R.L.; Jiles, D.C.; Teng, B.H.; Luo, Y.

2015-01-01

This paper presents the structure, magnetic properties, and magnetocaloric effect of the polycrystalline compound GdNiAl 2 . Powder X-ray diffraction (XRD) measurement and Rietveld refinement revealed that GdNiAl 2 alloy is CuMgAl 2 -type phase structure with about 1 wt% GdNi 2 Al 3 secondary phase. Magnetic measurements suggest that the compound is ferromagnetic and undergoes a second-order phase transition near 28 K. The maximum value of magnetic entropy change reaches 16.0 J/kg K for an applied magnetic field change of 0–50 kOe and the relative cooling power was 6.4×10 2 J/kg. It is a promising candidate as a magnetocaloric material working near liquid hydrogen temperature (~20 K) exhibiting large relative cooling power. - Highlights: • Preferred orientation with axis of [010] was found in the GdNiAl 2 compound. • The ΔS Mmax and the RCP are 16.0 J/kg K and 640 J/kg, respectively, for ΔH=50 kOe. • Relative low rare earth content in GdNiAl 2 comparing with other candidates

Solution growth of Tb doped Gd_2O_3 film

International Nuclear Information System (INIS)

Ghosh, M.; Pitale, S.; Desai, D.G.; Patra, G.D.; Sen, S.; Gadkari, S.C.

2016-01-01

Nanomaterials of Gd_2O_3 have proven applications in medical imaging and cancer therapy due to the presence of element Gd. Also Gd_2O_3 films have been grown by vapor phase method as well as self assembly in solution and studied as a high-k dielectric and efficient luminescence material. Here, we report a method to obtain Tb doped Gd_2O_3 film by solution growth method followed by suitable heat treatment. Uniform films of Tb doped Gadolinium hydroxycarbonate have been deposited on fused quartz substrates kept inside a solution containing gadolinium nitrate, terbium nitrate and Urea maintained at 90°C. Gadolinium hydroxy-carbonate films are then treated at 800°C for 2 hour to obtain Tb doped cubic Gd_2O_3 as confirmed by X-ray diffraction measurement. The photoluminescence spectra display characteristic Tb emission at 544 nm when excited at 285 nm. The lifetime of Tb emission is found to be of the order of few microseconds. (author)

Semiportable load-cell-based weighing system prototype of 18.14-metric-ton (20-ton) capacity for UF6 cylinder weight verifications: description and testing procedure

International Nuclear Information System (INIS)

McAuley, W.A.

1984-01-01

The 18.14-metric-ton-capacity (20-ton) Load-Cell-Based Weighing System (LCBWS) prototype tested at the Oak Ridge (Tennessee) Gaseous Diffusion Plant March 20-30, 1984, is semiportable and has the potential for being highly accurate. Designed by Brookhaven National Laboratory, it can be moved to cylinders for weighing as opposed to the widely used operating philosophy of most enrichment facilities of moving cylinders to stationary accountability scales. Composed mainly of commercially available, off-the-shelf hardware, the system's principal elements are two load cells that sense the weight (i.e., force) of a uranium hexafluoride (UF 6 ) cylinder suspended from the LCBWS while the cylinder is in the process of being weighed. Portability is achieved by its attachment to a double-hook, overhead-bridge crane. The LCBWS prototype is designed to weigh 9.07- and 12.70-metric ton (10- and 14-ton) UF 6 cylinders. A detailed description of the LCBWS is given, design information and criteria are supplied, a testing procedure is outlined, and initial test results are reported. A major objective of the testing is to determine the reliability and accuracy of the system. Other testing objectives include the identification of (1) potential areas for system improvements and (2) procedural modifications that will reflect an improved and more efficient system. The testing procedure described includes, but is not limited to, methods that account for temperature sensitivity of the instrumentation, the local variation in the acceleration due to gravity, and buoyance effects. Operational and safety considerations are noted. A preliminary evaluation of the March test data indicates that the LCBWS prototype has the potential to have an accuracy in the vicinity of 1 kg

Molecular electrophosphorescence in (Sm, Gd)-{beta}-diketonate complex blend for OLED applications

Energy Technology Data Exchange (ETDEWEB)

Reyes, R., E-mail: fisicaplic@hotmail.com [Facultad de Ingenieria Quimica y Textil, Universidad Nacional de Ingenieria, UNI, Av. Tupac Amaru 210, Lima 31, Peru (Peru); Cremona, M. [DIMAT - Divisao de Metrologia de Materiais, Instituto Nacional de Metrologia, Normalizacao e Qualidade Industrial, INMETRO, Duque de Caxias, RJ (Brazil); Departamento de Fisica, Pontificia Universidade Catolica do Rio de Janeiro, PUC-Rio, C.P. 38071, Rio de Janeiro, RJ, CEP 22453-970 (Brazil); Teotonio, E.E.S. [Departamento de Quimica, CCEN, Universidade Federal da Paraiba, UFPB, C.P. 5093, Joao Pessoa, PB, CEP 5805-970 (Brazil); Brito, H.F. [Instituto de Quimica, Universidade de Sao Paulo, USP, C.P. 26077, Sao Paulo, SP, CEP 05599-970 (Brazil); Malta, O.L. [Departamento de Quimica Fundamental, CCEN, Universidade Federal de Pernambuco, Cidade Universitaria, Recife, PE, CEP 50670-901 (Brazil)

2013-02-15

In this work the preparation and characterization of the triple-layer organic light-emitting diode (OLED) using a mixture of the samarium and gadolinium {beta}-diketonate complexes [Sm{sub 0.5}Gd{sub 0.5}(TTA){sub 3}(TPPO){sub 2}] as emitting layer is reported. The OLED's devices contain 1-(3-methylphenyl)-1,2,3,4-tetrahydroquinoline-6-carboxyaldehyde-1, 1'-diphenylhydrazone (MTCD) as hole-transporting layer and tris(8-hydroxyquinoline aluminum) (Alq{sub 3}) as electron transporting layer. The electroluminescence spectrum present emission narrow bands from the {sup 4}G{sub 5/2}{yields}{sup 6}H{sub J} transitions (where J=5/2, 7/2 and 9/2) characteristic of the Sm{sup 3+} ion. These sharp lines are overlapped with a broad band attributed to the electrophosphorescence from the T{sub 1}{yields}S{sub 0} transition in the ligand TTA. The intramolecular energy transfer is discussed and applied on the change of the emission color of the organic LEDs at different bias voltages. - Highlights: Black-Right-Pointing-Pointer Samarium and gadolinium complexes. Black-Right-Pointing-Pointer OLED with complex blend (Sm,Gd). Black-Right-Pointing-Pointer Electrophosphorescence emission detection. Black-Right-Pointing-Pointer Application in OLED changing the color emission.

Evaluation of hypothetical (153)Gd source for use in brachytherapy.

Science.gov (United States)

Ghorbani, Mahdi; Behmadi, Marziyeh

2016-01-01

The purpose of this work is to evaluate the dosimetric parameters of a hypothetical (153)Gd source for use in brachytherapy and comparison of the dosimetric parameters with those of (192)Ir and (125)I sources. Dose rate constant, the radial dose function and the two dimensional (2D) anisotropy function data for the hypothetical (153)Gd source were obtained by simulation of the source using MCNPX code and then were compared with the corresponding data reported by Enger et al. A comprehensive comparison between this hypothetical source and a (192)Ir source with similar geometry and a (125)I source was performed as well. Excellent agreement was shown between the results of the two studies. Dose rate constant values for the hypothetical (153)Gd, (192)Ir, (125)I sources are 1.173 cGyh(-1) U(-1), 1.044 cGyh(-1) U(-1), 0.925 cGyh(-1) U(-1), respectively. Radial dose function for the hypothetical (153)Gd source has an increasing trend, while (192)Ir has more uniform and (125)I has more rapidly falling off radial dose functions. 2D anisotropy functions for these three sources indicate that, except at 0.5 cm distance, (192)Ir and (125)I have more isotropic trends as compared to the (153)Gd source. A more uniform radial dose function, and 2D anisotropy functions with more isotropy, a much higher specific activity are advantages of (192)Ir source over (153)Gd. However, a longer half-life of (153)Gd source compared to the other two sources, and lower energy of the source with respect to (192)Ir are advantages of using (153)Gd in brachytherapy versus (192)Ir source.

Thermal properties of GdSr{sub 2}RuCu{sub 2}O{sub 8-{delta}} based mixtures in the GdSr{sub 2}RuO{sub 6}-CuO pseudo-binary system

Energy Technology Data Exchange (ETDEWEB)

Gombos, Marcello [Laboratorio Regionale Supermat CNR-INFM Via Salvador Allende, I-84081 Baronissi (Italy); Dipartimento di Fisica ' E.R.Caianiello' , Universita di Salerno, Via Salvador Allende, I-84081 Baronissi (Italy)], E-mail: gombos@sa.infn.it; Ciancio, Regina; Vecchione, Antonio; Pace, Sandro [Laboratorio Regionale Supermat CNR-INFM Via Salvador Allende, I-84081 Baronissi (Italy); Dipartimento di Fisica ' E.R.Caianiello' , Universita di Salerno, Via Salvador Allende, I-84081 Baronissi (Italy)

2007-09-01

GdSr{sub 2}RuCu{sub 2}O{sub 8-{delta}} (Gd1212) rutheno-cuprate compound is widely studied because it shows the coexistence of superconductivity and highly anisotropic magnetic ordering in the same cell. Anyway the nature of the magnetic ordering is still debated and the fabrication of macroscopic samples oriented along a crystallographic axis, that could help to clarify its details, appears to be quite difficult. For this reason, accurate investigation on Gd1212 incongruent melting reaction, producing liquid copper oxide and the solid GdSr{sub 2}RuO{sub 6} (Gd1210), appears to be necessary to improve the fabrication of crystallographically oriented bulk superconducting samples. Thermo-gravimetric and differential thermal measurements were performed to analyse the thermal behaviour up to 1200 deg. C and the melting temperatures of different mixtures of Gd1212 with Gd1210 or CuO, in view to perform a scan of the whole CuO-Gd1212-Gd1210 coexistence line of the Gd-Sr-Ru-Cu-O phase diagram. Dependence on the atmosphere and the formation of different spurious phases was also studied.

Sign change of magnetoresistance in Gd-doped amorphous carbon granular films.

Science.gov (United States)

Ding, Shihao; Jin, Chao; Fan, Ziwei; Li, Peng; Bai, Haili

2015-11-11

Gd/C granular films with 11% Gd were fabricated by facing-target magnetron sputtering at room temperature and then annealed at 300-650 °C for 1.5 h. A magnetoresistance of -82% was obtained in the Gd/C films annealed at 650 °C at 3 K under a magnetic field of 50 kOe. A sign change of the magnetoresistance from negative to positive and then back to negative was observed in all samples as the temperature decreases. Grain boundary scattering effects, wave-function-shrinkage, cotunneling and Gd-Gd interactions account for the mechanisms of the magnetoresistance effects in different temperature regions. The sign of the magnetoresistance also varies as the magnetic field increases. At the transition temperature of 25 K, the wave-function-shrinkage effect competes with cotunneling and Gd-Gd interactions at different magnetic fields. The competition between the wave-function-shrinkage effect and the grain boundary scattering effect is approximately at the transition temperature of 100 K. The temperature range of positive magnetoresistance expands and transition temperatures are changed as the annealing temperature increases. It is related to the expansion of the temperature region for the wave-function-shrinkage effect which occurs in the Mott variable range hopping conduction mechanism.

Study on the Mechanical Properties and Corrosion Behaviors of Fe-(20, 45) wt%Gd Intermetallics

Energy Technology Data Exchange (ETDEWEB)

Kang, Bo Kyeong; Baik, Youl; Choi, Yong [Dankook University, Chungnam (Korea, Republic of); Moon, Byung Moon [Korea Institute of Industrial Technology, Incheon (Korea, Republic of)

2017-02-15

Fe-(20, 45 wt%) Gd intermetallics were vacuum arc melted as the mother alloy of a neutron shielding and absorbing material. The structure of the cast Fe-20 wt%Gd intermetallics had primary dendrites with a short width of about 2 μm, which became coarse with increasing Gd content. The final compositions of the Fe-20 wt%Gd and Fe-45 wt%Gd intermetallics determined by Rietveld refinement were mainly Fe{sub 3}Gd with 26.6 at%Fe{sub 2}Gd, and Fe{sub 3}Gd with various intermetallics like 13.9 at%Fe{sub 2}Gd, 7.3 at%Fe{sub 9}Gd and 3.9 at%Fe{sub 17}Gd{sub 2}, respectively. The micro-hardnesses, yield strength, ultimate compressive strength and elongation of the Fe-20 wt%Gd intermetallics were 629±12 Hv, 753 MPa, 785 MPa and 4%, respectively, and those of the Fe-45 wt%Gd intermetallics were 741±13 Hv, 772 MPa, 823 MPa and 3%. Passivity was not present in artificial sea water at room temperature. The corrosion potentials and the corrosion rates of the Fe-20 wt%Gd and Fe-45 wt%Gd intermetallics were –624 mV{sub SHE}, 2.771 mA/cm{sup 2} , and –804 mV{sub SHE}, 3.397 mA/cm{sup 2} , respectively. The corroded surface of the Fe-Gd intermetallics contained corrosion products like gadolinium with iron, which detached to leave a trail of pits.

MRI contrast enhancement of the lung using as Gd-DTPA aerosol

International Nuclear Information System (INIS)

Bockisch, A.; Harvey, R.C.; Davis, M.A.; Kabalka, G.W.

1993-01-01

The efficacy of a Gd-DTPA aerosol to enhance ventilated lung parenchyma was evaluated in an MR study in anesthetized female beagle dogs. Ventilation of a 1.0-M Gd-DTPA solution was performed using a commercially available atomizer. MR imaging was performed at a 1.9 T whole body imager with an acquisition mode that was gated to respiration. To quantify the amount of ventilated Gd-DTPA experiments were repeated with 99m Tc-DTPA under identical conditions. Using ventral and dorsal digital scintigraphy, the amount of Gd-DTPA in both lungs were determined. MR imaging showed on increase of signal intensity of 70% following Gd-DTPA ventilation. Because of the inherently low signal intensity of lung parenchyma this degree of contrast enhancement is too small to be clinically useful. (orig.) [de

Homogeneity and microstructure study of Gd2O3-UO2 pellets

International Nuclear Information System (INIS)

Pan Ying; Gao Dihua; Guo Yibai; Zhu Shuming

1994-10-01

The microstructure of Gd 2 O 3 -UO 2 pellets (0∼10 wt%) prepared in different conditions, the homogeneity distribution of Gd 2 O 3 in the pellets and the lattice parameter of solid solution are studied by metalloscope, WDS, EDAX, SEM-image processing system, XRD and image analyzer. The theoretical density has been calculated. The effect of size and content of Gd 2 O 3 particles, the blend process, the sintering temperature and time, and the sintering atmosphere on the microstructure of Gd 2 O 3 pellets and the homogeneity of Gd 2 O 3 in the pellets are studied. (16 refs., 10 figs., 8 tabs.)

Twitching motility and biofilm formation are associated with tonB1 in Xylella fastidiosa.

Science.gov (United States)

Cursino, Luciana; Li, Yaxin; Zaini, Paulo A; De La Fuente, Leonardo; Hoch, Harvey C; Burr, Thomas J

2009-10-01

A mutation in the Xylella fastidiosa tonB1 gene resulted in loss of twitching motility and in significantly less biofilm formation as compared with a wild type. The altered motility and biofilm phenotypes were restored by complementation with a functional copy of the gene. The mutation affected virulence as measured by Pierce's disease symptoms on grapevines. The role of TonB1 in twitching and biofilm formation appears to be independent of the characteristic iron-uptake function of this protein. This is the first report demonstrating a functional role for a tonB homolog in X. fastidiosa.

Defect-band mediated ferromagnetism in Gd-doped ZnO thin films

KAUST Repository

Venkatesh, S.

2015-01-07

Gd-doped ZnO thin films prepared by pulsed laser deposition with Gd concentrations varying from 0.02–0.45 atomic percent (at. %) showed deposition oxygen pressure controlled ferromagnetism. Thin films prepared with Gd dopant levels (<Gd 0.112 at. %) at low oxygen deposition pressure (<25 mTorr) were ferromagnetic at room temperature. Negative magnetoresistance, electric transport properties showed that the ferromagnetic exchange is mediated by a spin-split defect band formed due to oxygen deficiency related defect complexes. Mott\\'s theory of variable range of hopping conduction confirms the formation of the impurity/defect band near the Fermi level.

Response Surface Model (RSM)-based Benefit Per Ton Estimates

Science.gov (United States)

The tables below are updated versions of the tables appearing in The influence of location, source, and emission type in estimates of the human health benefits of reducing a ton of air pollution (Fann, Fulcher and Hubbell 2009).

New look at magnetism in single-crystal Gd-Y alloys

International Nuclear Information System (INIS)

Ito, T.; Legvold, S.; Beaudry, B.J.

1981-01-01

Magnetic susceptibility, electrical resistivity, and specific-heat measurements have been made on a number of polycrystalline and single-crystal samples of Gd-rich Gd-Y alloys. It has been found (i) that samples with more than 30 at. % Y exhibit a helical structure phase; (ii) that samples between 10 and 30 at. % Y exhibit two different Curie-Weiss regimes leading to ''double'' ferromagnetism; and (iii) that samples with less than 10 at. % Y have Gd-like behavior

Magnetoelastic behaviour of Gd sub 5 Ge sub 4

CERN Document Server

Magen, C; Algarabel, P A; Marquina, C; Ibarra, M R

2003-01-01

A complete investigation of the complex magnetic behaviour of Gd sub 5 Ge sub 4 by means of linear thermal expansion and magnetostriction measurements (5-300 K, 0-120 kOe) has been carried out. Our results support the suggested existence in this system of a coupled crystallographic-magnetic transition from a Gd sub 5 Ge sub 4 -type Pnma (antiferromagnetic) to a Gd sub 5 Si sub 4 -type Pnma (ferromagnetic) state. Strong magnetoelastic effects are observed at the field-induced first-order magnetic-martensitic transformation. A revised magnetic and crystallographic H- T phase diagram is proposed.

MRI of the liver with the new contrast medium Gd-BOPTA

International Nuclear Information System (INIS)

Vogl, T.J.; Pegios, W.; Balzer, J.; Lissner, J.; Pirovano, G.

1992-01-01

A phase 1 study on 8 normals has been carried out to determine the effectiveness and safety during MRI of a new hepatobiliary contrast medium Gd-BOPTA for causing enhancement of the upper abdominal organs. Gradient echo sequences (flash), T 1 and T 2 -weighted spin echo sequences and turbo-flash sequences were used. The contrast medium was given as a single infusion in various concentrations (0.005, 0.05, 0.1 and 0.2 mmol/kg body weight). Optimal contrast of liver parenchyma was obtained with a dose of 0.05-0.1 mmol/kg body weight, resulting in contrast increase of 149.1% during gradient echo sequences and 107.8% during T 1 spin echo sequences. In general, the increased contrast lasted for about two hours. Because of the biliary and renal excretion there was an enormous increase in signal intensity of the bile ducts and a significant increase in the kidneys and ureters. The results of the first in-vivo-trial of Gd-BOPTA encourages the performance of further clinical studies of this new hepatobiliary contrast medium. (orig.) [de

Renal enhancement and excretion of the hepatobiliary contrast agent Gd-EOB-DTPA

International Nuclear Information System (INIS)

Zangos, S.; Hammerstingl, R.; Mack, M.G.; Straub, R.; Engelmann, K.; Eichler, K.; Vogl, T.J.

2001-01-01

Purpose: To evaluate the clinical value of the renal clearance using MR imaging with different doses of gadolinium ethoxybenzyl-DTPA (Gd-EOB-DTPA) in comparison to gadolinium DTPA (Gd-DTPA). Material and Methods: In a double-blind and randomized clinical phase II study. MR imaging at 1.5 T was performed in 61 patients with five different doses of Gd-EOB-DTPA (3, 6, 12.5, 25 and 50 μmol/kg b.w. as a bolus injection). The study protocol comprised T 1 - and T 2 -weighted spin-echo magnetic resonance and two-dimensional fast low-angle shot imaging before and at increasing intervals for up to 45 min after injection of Gd-EOB-DTPA. These images were compared with Gd-DTPA-enhanced imaging (0.1 mmol/kg b. w. as a bolus injection). Results: After bolus injection of the hepatobiliary MR contrast agent Gd-EOB-DTPA a renal elimination was observed. Immediately after the injection of Gd-EOB-DTPA until the eighth minute a corticomedullary enhancement of the kidney was conspicuous. After the fourth minute a contrast enhancement could be seen in the renal pelvis. The best enhancement was noted after 20 minutes in the FLASH GRE and T 1 -weighted images with good pelvicaliceal contrast. After 45 minutes an outflow of Gd-EOB-DTPA into the ureter could be observed. Conclusion: In addition to the hepatobiliary secretion Gd-EOB-DTPA appears useful for the evaluation of renal structures and renal function on account of the renal excretion without diuretic preparation of the patients. (orig.) [de

Confined Mobility of TonB and FepA in Escherichia coli Membranes.

Directory of Open Access Journals (Sweden)

Yoriko Lill

Full Text Available The important process of nutrient uptake in Escherichia coli, in many cases, involves transit of the nutrient through a class of beta-barrel proteins in the outer membrane known as TonB-dependent transporters (TBDTs and requires interaction with the inner membrane protein TonB. Here we have imaged the mobility of the ferric enterobactin transporter FepA and TonB by tracking them in the membranes of live E. coli with single-molecule resolution at time-scales ranging from milliseconds to seconds. We employed simple simulations to model/analyze the lateral diffusion in the membranes of E.coli, to take into account both the highly curved geometry of the cell and artifactual effects expected due to finite exposure time imaging. We find that both molecules perform confined lateral diffusion in their respective membranes in the absence of ligand with FepA confined to a region [Formula: see text] μm in radius in the outer membrane and TonB confined to a region [Formula: see text] μm in radius in the inner membrane. The diffusion coefficient of these molecules on millisecond time-scales was estimated to be [Formula: see text] μm2/s and [Formula: see text] μm2/s for FepA and TonB, respectively, implying that each molecule is free to diffuse within its domain. Disruption of the inner membrane potential, deletion of ExbB/D from the inner membrane, presence of ligand or antibody to FepA and disruption of the MreB cytoskeleton was all found to further restrict the mobility of both molecules. Results are analyzed in terms of changes in confinement size and interactions between the two proteins.

Relativistic electronic structure calculations on endohedral Gd rate at C60, La rate at C60, Gd rate at C74, and La rate at C74

International Nuclear Information System (INIS)

Lu, J.; Zhang, X.; Zhao, X.

2000-01-01

Relativistic discrete-variational local density functional calculations on endohedral Gd rate at C 60 , La rate at C 60 ,Gd rate at C 74 , and La rate at C 74 are performed. All the C 60 - and C 74 -derived levels are lowered upon endohedral Gd and La doping. Both the Gd (4f 7 5d 1 6s 2 ) and La (5d 1 6s 2 ) atoms only donate their two 6s valence electrons to the cages, leaving behind their 5d electrons when they are placed at the cage centers. Compared with large-band-gap C 60 , small-band-gap C 74 and Gd (La)-metallofullerenes have strong both electron-donating and electron-accepting characters, and the calculated ionization potentials and electron affinities for them agree well with the available experimental data. (orig.)

Gd-DTPA in MRI. Clinical experience in intracranial pathologies

Energy Technology Data Exchange (ETDEWEB)

Bradac, G B; Riva, A; Berger, T; Stura, G; Duca, S

1988-01-01

Sixty-seven patients with various intracranial pathologies were studied using Gd-DTPA as a contrast medium applied to MRI. This paramagnetic substance was well tolerated by all patients, and proved particularly useful in improving the diagnosis of extra-axial tumors, in which a rich enhancement was always present. Gd-DTPA allowed a better definition of the tumor outlines, as well as its differentiation from edema, and the demonstration of its relationship to brain parenchyma and cerebral vessels. This was particularly true for meningiomas, which often display poor contrast enhancement at MRI. Even though acoustic neuromas had, as a rule, high signal intensity, Gd-DTPA was useful to precisely recognise the intracanalar part of the tumor. The value of Gd-DTPA was less evident in intra-axial lesions. It proved nonetheless useful in demonstrating the portions of the tumor where, due to alterations in BBB, enhancement was present. This allowed both to characterized the lesion and to perform accurate biopsies.

Low-temperature magnetic properties of GdCoIn5

Science.gov (United States)

Betancourth, D.; Facio, J. I.; Pedrazzini, P.; Jesus, C. B. R.; Pagliuso, P. G.; Vildosola, V.; Cornaglia, Pablo S.; García, D. J.; Correa, V. F.

2015-01-01

A comprehensive experimental and theoretical study of the low temperature properties of GdCoIn5 was performed. Specific heat, thermal expansion, magnetization and electrical resistivity were measured in good quality single crystals down to 4He temperatures. All the experiments show a second-order-like phase transition at 30 K probably associated with the onset of antiferromagnetic order. The magnetic susceptibility shows a pronounced anisotropy below TN with an easy magnetic axis perpendicular to the crystallographic ĉ-axis. Total energy GGA+U calculations indicate a ground state with magnetic moments localized at the Gd ions and allowed a determination of the Gd-Gd magnetic interactions. Band structure calculations of the electron and phonon contributions to the specific heat together with Quantum Monte Carlo calculations of the magnetic contributions show a very good agreement with the experimental data. Comparison between experiment and calculations suggests a significant anharmonic contribution to the specific heat at high temperature (T ≳ 100 K).

The enhanced activity of mass-selected PtxGd nanoparticles for oxygen electroreduction

DEFF Research Database (Denmark)

Velazquez-Palenzuela, Amado Andres; Masini, Federico; Pedersen, Anders Filsøe

2015-01-01

Mass-selected platinum–gadolinium alloy nanoparticles (PtxGd NPs) are synthesized for the first time as oxygen reduction reaction (ORR) electrocatalysts using the gas aggregation technique, under ultrahigh vacuum (UHV) conditions. The morphology of the PtxGd catalysts is characterized, and their ......Mass-selected platinum–gadolinium alloy nanoparticles (PtxGd NPs) are synthesized for the first time as oxygen reduction reaction (ORR) electrocatalysts using the gas aggregation technique, under ultrahigh vacuum (UHV) conditions. The morphology of the PtxGd catalysts is characterized...

Multiple metamorphoses for EdF and GdF

International Nuclear Information System (INIS)

Jemain, A.

2004-01-01

The draft of law, modifying the statute of the French electric and gas utilities, Electricite de France (EdF) and Gaz de France (GdF), that the French government has presented to the Council of State, mixes some European and French preoccupations. The reason is the urgency of the planning and the date line of July 1, 2004 with the opening of the gas and power markets to 3.5 millions of professionals. The draft includes the obligations and missions of public utility of both companies, the transposition of the European directives, the conclusions of the negotiation of retirement pensions with the syndicate organizations, and the transformation of both public companies into anonymous companies. Short paper. (J.S.)

The new carbodiimide Li_2Gd_2Sr(CN_2)_5 having a crystal structure related to that of Gd_2(CN_2)_3

International Nuclear Information System (INIS)

Unverfehrt, Leonid; Stroebele, Markus; Meyer, H. Juergen

2013-01-01

The new carbodiimide compounds Li_2RE_2Sr(CN_2)_5 (RE = Sm, Gd, Eu, Tb) were prepared by a straight forward solid state metathesis reaction of REF_3, SrF_2, and Li_2(CN_2) at around 600 C. The crystal structure of Li_2Gd_2Sr(CN_2)_5 was solved based on X-ray single-crystal diffraction data. Corresponding Li_2RE_2Sr(CN_2)_5 compounds were analyzed by isotypic indexing of their powder patterns. The crystal structure of Li_2Gd_2Sr(CN_2)_5 can be well related to that of Gd_2(CN_2)_3, because both structures are based on layered structures composed of close packed layers of [N=C=N]"2"- sticks, alternating with layers of metal ions. The crystal structure of Li_2Gd_2Sr(CN_2)_5 can be considered to contain an ABC layer sequence of [N = C=N]"2"- layers with the interlayer voids being occupied by (three) distinct types of cations. (Copyright copyright 2013 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

A method to press powder at 6000 ton using small amount of explosive

Science.gov (United States)

Hilmi, Ahmad Humaizi; Azmi, Nor Azmaliana; Ismail, Ariffin

2017-12-01

Large die hydraulic press forces are one of the key instruments in making jumbo planes. The machine can produce aircraft components such as wing spars, landing gear supports and armor plates. Superpower nations such as USA, Russia, Germany, Japan, Korea and China have large die hydraulic press which can press 50,000 tons. In Malaysia, heavy-duty press is available from companies such as Proton that builds chassis for cars. However, that heavy-duty press is not able to produce better bulkhead for engines, fuselage, and wings of an aircraft. This paper presents the design of an apparatus that uses 50 grams of commercial grade explosives to produce 6000 tons of compaction. This is a first step towards producing larger scale apparatus that can produce 50,000-ton press. The design was done using AUTODYN blast simulation software. According to the results, the maximum load the apparatus can withstand was 6000 tons which was contributed by 50 grams of commercial explosive(Emulex). Explosive size larger than 50 grams will lead to catastrophic failure. Fabrication of the apparatus was completed. However, testing of the apparatus is not presented in this article.

The isolation and the separation of Sm, Gd, Dy by extraction

International Nuclear Information System (INIS)

Biyantoro, D.; Lahagu, F.; Basuki, K.T.; Handini, T.; Rosyidin

1996-01-01

The isolation of yttrium and separation of Sm, Gd, y with extraction has been investigated. The steps of the process include of this research were the production the concentrate of lanthanide, the dilution, the isolation of yttrium, and the separation of the Sm, Gd, Dy. The first step was the digestion of xenotime sand, the extraction, the dilution, the filtration, the precipitation, the baking production a lanthanide oxide. The step was the separation of yttrium, the stripping, and the calcination production of yttrium oxide. And the third process was the separation of Sm, Gd, Dy by extraction process using method liquid-liquid extraction with extractant of D 2 EHPA and a solvent of dodecane. From the result have been found concentration of yttrium oxide = 88,71 %. The optimum condition of the separation of Gd/Dy have been found : the concentration of HNO 3 = 0,5 M, time of extraction = 15 minutes, and the concentration of extractant = 30 % D 2 EHPA in dodecane. The results of this condition were the distribution coefficient of Gd = 2,226, the distribution coefficient of Dy = 3,762, and the separation factor of Gd/Dy = 0,592. (author)

The fate of Gd and chelate following intravenous injection of gadodiamide in rats

International Nuclear Information System (INIS)

Moerk Kindberg, Grete; Uran, Steinar; Friisk, Grete; Martinsen, Ivar; Skotland, Tore

2010-01-01

The biodistribution of gadolinium (Gd) and chelate was studied in rats injected intravenously with a commercially available gadodiamide magnetic resonance contrast agent spiked with trace amounts of 14 C-labelled GdDTPA-BMA. Biodistribution of the 14 C-labelled ligand in whole animals was visualised using quantitative whole-body autoradiography, and quantified in individual tissue samples by analysing for radioactivity using beta-counting. Biodistribution of Gd was measured by inductively coupled plasma atomic emission spectroscopy (ICP-AES) and inductively coupled plasma sector field mass spectrometry (ICP-SF-MS). The injected dose was rapidly excreted, with only 1.0% remaining in the body at 24 h. The radioactivity thereafter was mainly associated with kidney cortex, liver, lung, muscle and skin, with a similar rate of clearance for both ligand and Gd from these tissues. The ratio between 14 C-labelled substance and Gd was not significantly different from that of the injected substance in most tissue samples up to 24 h after injection; the ratio then slowly decreased. The data clearly show that measurements of Gd concentration alone in tissue samples from animals injected with Gd-based contrast agents (GBCAs) cannot be used as a measure of Gd released from the ligand. To our knowledge, such measurements comparing Gd and ligand concentrations and distribution in tissue samples have not been published previously for any of the commercial GBCAs. (orig.)

Thermal behaviour of GdCo1-xMnxO3 cobaltates

Science.gov (United States)

Thakur, Rasna; Thakur, Rajesh K.; Gaur, N. K.

2018-05-01

With the objective of exploring the unknown thermodynamic behavior of GdCo1-xMnxO3 family, we present here an investigation of the temperature-dependent (10K≤T≤1000K) thermodynamic properties of GdCo1-xMnxO3 (x=0.1 to 0.8). The specific heat of GdCoO3 with Mn doping in the perovskite structure at B-site has been studied by means of a Modified Rigid Ion Model (MRIM). The cohesive energy, specific heat (C), volume thermal expansion (α) and Gruneisen parameter (γ) of GdCo1-xMnxO3 compounds are also discussed.

MRI contrast enhancement of the lung using a Gd-DTPA aerosol

International Nuclear Information System (INIS)

Bockisch, A.; Harvey, R.C.; Davis, M.A.; Kabalka, G.W.

1993-01-01

A MR imaging study was performed in anesthetized female beagle dogs to investigate the effectiveness of Gd-DTPA aerosol for contrast enhancement in ventilated lungs. Ventilation was performed using a commercially available atomizer to administer Gd-DTPA solution. MR imaging was performed with a 1.9 T whole body imager using respiratory gated acquisition. To define the amount of Gd-DTPA being trapped in the lungs identical experiments were performed with 99m Tc-DTPA. MR imaging confirmed at 70% contrast enhancement following inhalation of Gd-DTPA. Because of the inherently low signal intensity of lung parenchyma the degree of contrast enhancement is not sufficient for clinical application. (orig.) [de

Contribution to the WWER-440 Gd-assembly evolution

International Nuclear Information System (INIS)

Cudrnak, P.; Darilek, P.; Necas, V.

2009-01-01

Development activities, presented in the paper, contribute to the evolution of gadolinium fuel for the WWER-440 reactors. Short overview of existing and already proposed Gd-assemblies is given. Two new assembly types with improved features are described. Multiplication coefficients and pin power peaking factors of all mentioned gadolinium assemblies are compared. Animations of power distribution behaviour in selected Gd-assemblies are shown. (Authors)

GdF in Hungary: the East in progress

International Nuclear Information System (INIS)

Anon.

1996-01-01

After Germany and the Czech Republic, Gaz de France (GdF) has decided to export its know-how and technologies about natural gas into Hungary. Thanks to the Hungarian privatization program started in 1995, GdF could obtain the major participation in the Degaz and Egaz companies, two out of the five local distribution companies, and controls 22% of the natural gas distribution in Hungary. (J.S.)

Domain walls and exchange-interaction in Permalloy/Gd films

International Nuclear Information System (INIS)

Ranchal, R; Aroca, C; Lopez, E

2008-01-01

In this work we study the exchange coupling in Permalloy (Py)/gadolinium (Gd) bilayers. The exchange-coupled Py/Gd system is very temperature dependent and moreover the magnetization process in the Py layer is mainly due to domain wall (DW) displacements which are strongly controlled by pinning effects. We propose that this pinning could be caused by magnetostatic and exchange interactions between Py DWs and the magnetostrictive Gd layer. These effects mask the antiferromagnetic coupling between layers and, depending on temperature and Py thicknesses, apparent ferromagnetic coupling occurs. The study has been performed in the 80-300 K temperature range for different Py layer thicknesses and different Py induced anisotropies

A Rare Form of Guillan Barre Syndrome: A Child Diagnosed with Anti-GD1a and Anti-GD1b Positive Pharyngeal-Cervical-Brachial Variant

OpenAIRE

Uysalol, Metin; Tatlı, Burak; Uzel, Nedret; Çıtak, Agop; Aygün, Erhan; Kayaoğlu, Semra

2013-01-01

Background: Pharyngeal-cervical-brachial (PCB) variant is a rare form of Guillan-Barre Syndrome (GBS). Antibodies against other membrane proteins like GM1b and GD1a have been found only in a small number of patients with Guillan Barre syndrome variant. Case Report: Here, we report a 5.5 year-old boy diagnosed early with positive GD1a and GD1b gangliosides of Guillan-Barre syndrome pharyngeal cervical-Brachial variant, who improved and recovered fully in a short period. This is in co...

A Rare Form of Guillan Barre Syndrome: A Child Diagnosed with Anti-GD1a and Anti-GD1b Positive Pharyngeal-Cervical-Brachial Variant

OpenAIRE

Uysalol, Metin; Tatlı, Burak; Uzel, Nedret; Çıtak, Agop; Aygün, Erhan; Kayaoğlu, Semra

2014-01-01

Background: Pharyngeal-cervical-brachial (PCB) variant is a rare form of Guillan-Barre Syndrome (GBS). Antibodies against other membrane proteins like GM1b and GD1a have been found only in a small number of patients with Guillan Barre syndrome variant. Case Report: Here, we report a 5.5 year-old boy diagnosed early with positive GD1a and GD1b gangliosides of Guillan-Barre syndrome pharyngeal cervical-Brachial variant, who improved and recovered fully in a short period. This is in cont...

Ultrasensitive interplay between ferromagnetism and superconductivity in NbGd composite thin films

Science.gov (United States)

Bawa, Ambika; Gupta, Anurag; Singh, Sandeep; Awana, V. P. S.; Sahoo, Sangeeta

2016-01-01

A model binary hybrid system composed of a randomly distributed rare-earth ferromagnetic (Gd) part embedded in an s-wave superconducting (Nb) matrix is being manufactured to study the interplay between competing superconducting and ferromagnetic order parameters. The normal metallic to superconducting phase transition appears to be very sensitive to the magnetic counterpart and the modulation of the superconducing properties follow closely to the Abrikosov-Gor’kov (AG) theory of magnetic impurity induced pair breaking mechanism. A critical concentration of Gd is obtained for the studied NbGd based composite films (CFs) above which superconductivity disappears. Besides, a magnetic ordering resembling the paramagnetic Meissner effect (PME) appears in DC magnetization measurements at temperatures close to the superconducting transition temperature. The positive magnetization related to the PME emerges upon doping Nb with Gd. The temperature dependent resistance measurements evolve in a similar fashion with the concentration of Gd as that with an external magnetic field and in both the cases, the transition curves accompany several intermediate features indicating the traces of magnetism originated either from Gd or from the external field. Finally, the signatures of magnetism appear evidently in the magnetization and transport measurements for the CFs with very low (<1 at.%) doping of Gd.

Large magnetocaloric effect of GdNiAl{sub 2} compound

Energy Technology Data Exchange (ETDEWEB)

Dembele, S.N.; Ma, Z.; Shang, Y.F. [School of Physical Electronics, University of Electronic Science and Technology of China, Chengdu 610054 (China); Fu, H., E-mail: fuhao@uestc.edu.cn [School of Physical Electronics, University of Electronic Science and Technology of China, Chengdu 610054 (China); Balfour, E.A. [School of Physical Electronics, University of Electronic Science and Technology of China, Chengdu 610054 (China); Hadimani, R.L.; Jiles, D.C. [Department of Electrical and Computer Engineering, Iowa State University, Ames, IA 50011 (United States); Ames Laboratory, US Department of Energy, Ames, IA 50011 (United States); Teng, B.H.; Luo, Y. [School of Physical Electronics, University of Electronic Science and Technology of China, Chengdu 610054 (China)

2015-10-01

This paper presents the structure, magnetic properties, and magnetocaloric effect of the polycrystalline compound GdNiAl{sub 2}. Powder X-ray diffraction (XRD) measurement and Rietveld refinement revealed that GdNiAl{sub 2} alloy is CuMgAl{sub 2}-type phase structure with about 1 wt% GdNi{sub 2}Al{sub 3} secondary phase. Magnetic measurements suggest that the compound is ferromagnetic and undergoes a second-order phase transition near 28 K. The maximum value of magnetic entropy change reaches 16.0 J/kg K for an applied magnetic field change of 0–50 kOe and the relative cooling power was 6.4×10{sup 2} J/kg. It is a promising candidate as a magnetocaloric material working near liquid hydrogen temperature (~20 K) exhibiting large relative cooling power. - Highlights: • Preferred orientation with axis of [010] was found in the GdNiAl{sub 2} compound. • The ΔS{sub Mmax} and the RCP are 16.0 J/kg K and 640 J/kg, respectively, for ΔH=50 kOe. • Relative low rare earth content in GdNiAl{sub 2} comparing with other candidates.

Comparing the physical properties of Pr/Gd and Pr/Ce substitutions in Ru(Gd1.5Ce0.5)Sr2Cu2O10- δ

Science.gov (United States)

Khajehnezhad, A.; Nikseresht, N.; Hadipour, H.; Akhavan, M.

2008-06-01

We have compared the electrical and magnetic properties of Ru(Gd1.5- x Pr x )Ce0.5Sr2Cu2O10- δ (Pr/Gd samples) with x = 0.0, 0.01, 0.03, 0.033, 0.035, 0.04, 0.05, 0.06, 0.1 and RuGd1.5(Ce0.5- x Pr x ) Sr2 Cu2O10- δ (Pr/Ce samples) with x = 0.0, 0.01, 0.03, 0.05, 0.08, 0.1, 0.15, 0.2 prepared by the standard solid-state reaction technique. We obtained the XRD patterns for different samples with various x. The lattice parameters versus x for different substitutions have been obtained from Rietveld analysis. To determine how the magnetic and superconducting properties of these layered cuprate systems can be affected by Pr substitution, the resistivity, and magnetoresistivity, with H ext varying from 0.0 to 15 kOe, have been measured at various temperatures. Superconducting transition temperature T c and magnetic transition T irr , have been obtained through resistivity and ac susceptibility measurements. The T c suppression due to Pr/Gd and Pr/Ce substitutions show competition between pair breaking by magnetic impurities, hole doping due to different valances of ions, difference in ionic radii, and oxygen stoichiometry. Pr/Gd substitution suppresses superconductivity more rapidly than for Pr/Ce, showing that the effect of hole doping and magnetic impurity pair breaking is stronger than the difference in ionic radii. In Pr/Gd substitution, the small difference between the ionic radii of Pr3+,4+ and Gd3+, and absorption of more oxygen due to the higher valence of Pr with respect to Gd, decreases the mean Ru-Ru distance, and as a result, the magnetic exchange interaction becomes stronger with the increase of x. However, Pr/Ce substitution has the opposite effect. The magnetic parameters such as H c , obtained through magnetization measurements versus applied magnetic field isotherm at 77 K and room temperatures, become stronger with x in Pr/Gd and weaker with x in Pr/Ce substitution.

Identifying the influence of the intrinsic defects in Gd-doped ZnO thin-films

KAUST Repository

Flemban, Tahani H.; Sequeira, M. C.; Zhang, Z.; Venkatesh, S.; Alves, E.; Lorenz, K.; Roqan, Iman S.

2016-01-01

Gd-doped ZnO thin films were prepared using pulsed laser deposition at different oxygen pressures and varied Gd concentrations. The effects of oxygen deficiency-related defects on the Gd incorporation, optical and structural properties, were explored by studying the impact of oxygen pressure during deposition and post-growth thermal annealing in vacuum. Rutherford Backscattering Spectrometry revealed that the Gd concentration increases with increasing oxygen pressure for samples grown with the same Gd-doped ZnO target. Unexpectedly, the c-lattice parameter of the samples tends to decrease with increasing Gd concentration, suggesting that Gd-defect complexes play an important role in the structural properties. Using low-temperature photoluminescence(PL), Raman measurements and density functional theory calculations, we identified oxygen vacancies as the dominant intrinsic point defects. PL spectra show a defect band related to oxygen vacancies for samples grown at oxygen deficiency.

Identifying the influence of the intrinsic defects in Gd-doped ZnO thin-films

KAUST Repository

Flemban, Tahani H.

2016-02-08

Gd-doped ZnO thin films were prepared using pulsed laser deposition at different oxygen pressures and varied Gd concentrations. The effects of oxygen deficiency-related defects on the Gd incorporation, optical and structural properties, were explored by studying the impact of oxygen pressure during deposition and post-growth thermal annealing in vacuum. Rutherford Backscattering Spectrometry revealed that the Gd concentration increases with increasing oxygen pressure for samples grown with the same Gd-doped ZnO target. Unexpectedly, the c-lattice parameter of the samples tends to decrease with increasing Gd concentration, suggesting that Gd-defect complexes play an important role in the structural properties. Using low-temperature photoluminescence(PL), Raman measurements and density functional theory calculations, we identified oxygen vacancies as the dominant intrinsic point defects. PL spectra show a defect band related to oxygen vacancies for samples grown at oxygen deficiency.

Monte Carlo study of the magnetic properties of GdSb alloys

Energy Technology Data Exchange (ETDEWEB)

Masrour, R., E-mail: rachidmasrour@hotmail.com [Laboratory of Materials, Processes, Environment and Quality, Cady Ayyed University, National School of Applied Sciences, Sidi Bouzid, Safi, BP, 46000 63 (Morocco); LMPHE (URAC 12), Faculté des Sciences, Université Mohammed V-Agdal, Av. Ibn Batouta, B.P. 1014, Rabat (Morocco); Bahmad, L. [LMPHE (URAC 12), Faculté des Sciences, Université Mohammed V-Agdal, Av. Ibn Batouta, B.P. 1014, Rabat (Morocco); Hlil, E.K. [Institut Néel, CNRS et Université Joseph Fourier, BP 166, F-38042 Grenoble cedex 9 (France); Hamedoun, M. [Institute of Layers and Nanotechnologies, MAScIR, Rabat (Morocco); Benyoussef, A. [LMPHE (URAC 12), Faculté des Sciences, Université Mohammed V-Agdal, Av. Ibn Batouta, B.P. 1014, Rabat (Morocco); Institute of Layers and Nanotechnologies, MAScIR, Rabat (Morocco); Hassan II Academy of Science and Technology, Rabat (Morocco)

2014-03-15

The magnetic properties of antiferromagnetic GdSb layers have been studied using Monte Carlo simulations within the Ising model framework. The considered Hamiltonian includes first nearest-neighbor, an external magnetic field and a crystal field. The thermal magnetizations and magnetic susceptibilities are computed for a fixed size. In addition, the Néel temperature is deduced. The magnetization versus the exchange interactions and crystal field are studied for a fixed system size, N=5, 7 and 9 sites. The magnetic hysteresis cycle versus temperature is also established. - Highlights: • Determination of the Néel temperature of GdSb by MC simulations. • Magnetic hysteresis cycle of GdSb. • Determination of saturation magnetization and field coercive in GdSb.

Basivertebral plexus enhancement at MR imaging after Gd-DTPA administration

International Nuclear Information System (INIS)

Bronstein, A.D.; Cohen, W.A.; Maravilla, K.R.

1989-01-01

This paper presents a study to identify noncontrast versus post-Gd-DTPA MR images of the spine, we analyzed the basivertebral plexus. The authors postulate that there are consistent patterns of enhancement specific with Gd-DTPA. This is a retrospective examination of the normal appearance and enhancement patterns of the basivertebral plexus in 805 vertebrae of 30 patients who underwent pre- and post-Gd-DTPA T1-weighted sagittal MR imaging of the spine. All patients show enhancement of the basivertebral plexus in a significant number of vertebrae when pre-and postcontrast images are compared

Fuel densification study about uranium- 7% nanostructured gadolinium (Gd2O3)

International Nuclear Information System (INIS)

Serafim, Antonio da Costa

2016-01-01

The sintering process of UO 2 -Gd 2 O 3 pellets has been investigated in this work for its importance in the nuclear industry and for its complex behavior during sintering. Sintering blockage occurs from 1300 deg C upwards, when densification is shifted toward higher temperatures and the final density obtained is decreased. This research includes the development of nuclear fuel for power reactors in order to increase its efficiency inside the reactor core by raising the burnup. The use of nanosized Gd 2 O 3 was studied in the range from 10 to 30nm, which was added to UO 2 , trying to verify the occurrence of characteristic sintering blockage due to Kirkendall sintering effect observed in previous research. The samples were produced by dry mechanical mixture of UO 2 powder and 7% Gd 2 O 3 (macro- and nanostructured). The powders were compacted and the pellets were sintered at 1700 deg C under H 2 atmosphere. These results indicate that the characteristic blockage during sintering in macrostructured system UO 2 -Gd 2 O 3 occurred in the temperature range of 1300-1500 deg C, which slows down the densification. It was observed a less intense effect when using the nanostructured Gd 2 O 3 ; it took place at the temperature of 900 deg C, then facilitating to get an additional densification. The dilatometric tests indicated shrinkage of 22, 18 and 20% respectively in UO 2 pellets, macrostructured UO 2 -7% Gd 2 O 3 and nanostructured UO 2 -7%Gd 2 O 3 . We detected 2% higher shrinkage, when nanostructured Gd 2 O 3 was used instead of macrostructured Gd 2 O 3 , which is used commercially. Then, the nanostructured results showed more adequate density for nuclear fuel usage. (author)

Gd_2O_3 nanoparticles stabilized by hydrothermally modified dextrose for positive contrast magnetic resonance imaging

International Nuclear Information System (INIS)

Babić-Stojić, Branka; Jokanović, Vukoman; Milivojević, Dušan; Požek, Miroslav; Jagličić, Zvonko; Makovec, Darko; Arsikin, Katarina; Paunović, Verica

2016-01-01

Gd_2O_3 nanoparticles of a few nm in size and their agglomerates dispersed in dextrose derived polymer template were synthesized by hydrothermal treatment. The produced nanosized material was investigated by TEM, FTIR spectroscopy, SQUID measurements and NMR relaxometry. Biological evaluation of this material was done by crystal violet and MTT assays to determine the cell viability. Longitudinal and transverse NMR relaxivities of water diluted Gd_2O_3 nanoparticle dispersions measured at the magnetic field of 1.5 T, estimated to be r_1(Gd_2O_3)=9.6 s"−"1 mM"−"1 in the Gd concentration range 0.1–30 mM and r_2(Gd_2O_3)=17.7 s"−"1 mM"−"1 in the lower concentration range 0.1–0.8 mM, are significantly higher than the corresponding relaxivities measured for the standard contrast agent r_1(Gd-DTPA)=4.1 s"−"1 mM"−"1 and r_2(Gd-DTPA)=5.1 s"−"1 mM"−"1. The ratio of the two relaxivities for Gd_2O_3 nanoparticles r_2/r_1=1.8 is suitable for T_1-weighted imaging. Good MRI signal intensities of the water diluted Gd_2O_3 nanoparticle dispersions were recorded at lower Gd concentrations 0.2–0.8 mM. The Gd_2O_3 samples did not exert any significant cytotoxic effects at Gd concentrations of 0.2 mM and below. These properties of the produced Gd_2O_3 nanoparticles in hydrothermally modified dextrose make them promising for potential application in MRI for the design of a positive MRI contrast agent. - Highlights: • Gd_2O_3 nanoparticles (NPs) were stabilized by hydrothermally modified dextrose. • Magnetic moment per Gd"3"+ ion in the Gd_2O_3 NPs is much lower than that in the bulk. • The ratio r_2/r_1=1.8 for Gd_2O_3 NPs dispersions is favorable for T_1-weighted MRI. • Gd_2O_3 NPs dispersions had good MRI signal intensity just at lower Gd concentrations. • Gd concentrations of 0.2 mM and below in the Gd_2O_3 NPs dispersions were not toxic.

Hydrogen absorption in CexGd1−x alloys

International Nuclear Information System (INIS)

Bereznitsky, M.; Bloch, J.; Yonovich, M.; Schweke, D.; Mintz, M.H.; Jacob, I.

2012-01-01

Highlights: ► Ce x Gd 1−x alloys exhibit the most negative heats of hydride formation ever found. ► Thermodynamics of H absorption in Ce x Gd 1−x correlates with the alloys hardness. ► The entropies of H solution and hydride formation reflect the hydrogen vibrations. ► Terminal hydrogen solubilities change in a monotonic way between Ce and Gd. - Abstract: The effect of alloying on the thermodynamics of hydrogen absorption was studied for Ce x Gd 1−x alloys (0 ≤ x ≤ 1) at temperatures between 850 K and 1050 K in the 1–10 −4 Torr pressure range. The temperature-dependent hydrogen solubilities and plateau pressures for hydride formation were obtained from hydrogen absorption isotherms. The terminal hydrogen solubility (THS) at a given temperature changes in a monotonic way as a function of x. It is approximately three times higher in Gd, than in Ce, throughout the investigated temperature range. This monotonic behavior is opposed to that of many other substitutional alloys, for which the hydrogen terminal solubility increases with increasing solute concentrations. The enthalpies, ΔH f , and the entropies, ΔS f , of the dihydride formation exhibit a pronounced and broad negative minimum starting at x ≈ 0.15, yielding the most negative ΔH f values ever found for metal hydrides. On the other hand, the enthalpies and entropies of ideal solution display a positive trend at x = 0.15 and x = 0.3. Both behaviors are considered in view of a reported distinct variation of the Ce x Gd 1−x hardness as a function of x. The particular compositional variations of the entropies of solution and formation as a function of x reflect most likely the vibrational properties of the hydrogen atoms in the metal matrices.

Unoccupied surface electronic structure of Gd(0001)

International Nuclear Information System (INIS)

Li, D.; Dowben, P.A.; Ortega, J.E.; Himpsel, F.J.

1994-01-01

The unoccupied surface electronic structure of Gd(0001) was investigated with high-resolution inverse-photoemission spectroscopy. An empty surface state near E F is observed at bar Γ. Two other surface-sensitive features are also revealed at 1.2 and 3.1 eV above the Fermi level. Hydrogen adsorption on Gd surfaces was used to distinguish the surface-sensitive features from the bulk features. The unoccupied bulk-band critical points are determined to be Γ 3 + at 1.9 eV and A 1 at 0.8 eV

Structural and magnetic properties of Gd{sup 3+} ion substituted magnesium ferrite nanopowders

Energy Technology Data Exchange (ETDEWEB)

Elkady, Ashraf S. [Department of Physics, Faculty of Science, King Abdulaziz University, Jeddah (Saudi Arabia); Department of Reactor Physics, NRC, Atomic Energy Authority, Cairo (Egypt); Hussein, Shaban I. [Department of Reactor Physics, NRC, Atomic Energy Authority, Cairo (Egypt); Rashad, Mohamed M., E-mail: rashad133@yahoo.com [Central Metallurgical Research and Development Institute, Helwan, Cairo 11421 (Egypt)

2015-07-01

Nanocrystalline MgGd{sub x}Fe{sub 2−x}O{sub 4} powders (where x=0, 0.05, 0.1, 0.2, 0.25, 0.3) have been synthesized by the ethylene diamine tetraacetic acid (EDTA)-based sol–gel combustion method. X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, high resolution transmission electron microscopy (HRTEM) and vibrating sample magnetometer (VSM) were applied in order to study the effect of variation of Gd{sup 3+} ion substitution and its impact on crystal structure, crystallite size, lattice parameters, nanostructure and magnetic properties of the formed powders. XRD indicated that, after doping and calcination at 400 °C for 2 h, all samples have two spinel ferrite structures namely cubic and tetragonal phases, which are dependent on Gd{sup 3+} ion concentration. The cubic phase is found to increase with increasing the Gd{sup 3+} ion molar ratio up to 0.1, compared to pure MgFe{sub 2}O{sub 4} and higher Gd{sup 3+} content samples. Indeed, with increasing Gd{sup 3+} ion, the crystallite size was almost unchanged whereas the lattice parameter was found to increase. FT-IR spectrum showed broadening of the ν{sub 2} band and the presence of another band in the range (465–470 cm{sup −1}) upon adding Gd{sup 3+} ion, which confirm the presence of Gd{sup 3+} ion in addition to Fe{sup 3+} ion at octahedral site. Besides, these bands were assigned to the formation of (Gd{sup 3+}–O{sup 2−}) complexes at B-sites. HRTEM images showed that the studied samples consist of nanocrystallites having average particle sizes around 9 nm for pure MgFe{sub 2}O{sub 4} up to 27 and 42 nm for the Gd{sup 3+} ion substituted MgFe{sub 2}O{sub 4} of molar ratio 0.05 and 0.30, respectively. An examination of the magnetic properties revealed an increase in saturation magnetization with increasing Gd concentration incorporation up to x=0.1, as a result of the change of cubic and tetragonal spinel ratio and lattice parameters. Meanwhile, the formed powders exhibited

Radioluminescence studies of colloidal oleate-capped β-Na(Gd,Lu)F4:Ln3+ nanoparticles (Ln = Ce, Eu, Tb).

Science.gov (United States)

Cooper, Daniel R; Capobianco, John A; Seuntjens, Jan

2018-04-26

We report on the synthesis, characterization, and radioluminescence quantification of several new varieties of nanoparticles with the general composition β-NaLnF4, incorporating known luminescent activator/sensitizer pairs. Using Monte Carlo modeling to complement luminescence measurements, we have calculated the radioluminescence yields and intrinsic conversion efficiencies of colloidally-dispersed nanoparticles by comparison to an organic liquid scintillator. While five of the compositions had low to modest radioluminescence yields relative to bulk materials, colloidal β-Na(Lu0.65Gd0.2Tb0.15)F4 displayed a strong output of 39 460 photons per MeV absorbed, comparable to some of the best non-hygroscopic bulk crystal scintillators and X-ray phosphors such as Gd2O2S:Tb. Measurements of β-Na(Lu0.65Gd0.2Tb0.15)F4 powder samples revealed persistent luminescence as well as stable charge trapping, warranting further investigation.

Extraction of 152Gd from HFIR control plates

International Nuclear Information System (INIS)

Kohring, M.W.

1986-01-01

The primary method of 153 Gd production at the Oak Ridge National Lab. (ORNL) research reactors since 1980 has been the irradiation of a natural europium oxide powder (Eu 2 O 3 ) followed by the chemical extraction of the gadolinium fraction. The specific activity of the resulting source is 45 to 50 Ci/g with a radiochemical purity of > 99.99%. A potential alternative method involves the extraction of gadolinium from the europium-bearing region of highly radioactive, spent control plates used in the High Flux Isotope Reactor (HFIR), followed by neutron irradiation. This alternative to the traditional process is attractive in that chemical separation of the europium and gadolinium occurs before the 153 Gd production irradiation, thus reducing process and decay losses and, most significantly, the gadolinium is highly enriched in the parent isotope, 152 Gd. Investigation into the usefulness of the gadolinium isotopes contained in spent HFIR control plates began in the late 1960s. However, separation of the gadolinium from the europium to the purity levels required for a marketable specific activity could not be attained. Due to the recent increase in 153 Gd demand and separation process improvements, research into this valuable source of parent material was resurrected

Gd-DTPA administered MR imaging of intracranial mass lesions

International Nuclear Information System (INIS)

Mihara, Futoshi; Hirakata, Ryosuke; Hasuo, Kanehiro; Yasumori, Kotaro; Yoshida, Kisaku; Kuroiwa, Toshiro; Masuda, Kouji; Fukui, Masashi

1989-01-01

Magnetic resonance (MR) images of 13 intracranial mass lesions taken with the intravenous administration of gadolinium-DTPA were evaluated in comparison with precontrast computed tomography (CT), postcontrast CT, and precontrast MR. In the MR images taken with Gd-DTPA, tumor delineation improved in eight of 13 cases (62%) in comparison with precontrast MR images, and in seven of 13 cases (54%) in comparison with the overall evaluation of precontrast CT, postcontrast CT, and precontrast MR images. Tumor demarcation was unchanged in the remaining cases; no deterioration was observed with Gd-DTPA administration. MR imaging with Gd-DTPA should be performed to better evaluate the extent of intracranial mass lesions and to provide additional information. (author)

NMR measurements in milled RE-TM2 compounds (RE=Gd and TM=Co, Fe)

International Nuclear Information System (INIS)

Tribuzy, C.V.; Guimaraes, A.P.; Biondo, A.; Larica, C.; Alves, K.M.B.

1996-09-01

Milled samples of the Laves phase intermetallic compounds Gd Fe 2 and Gd CO 2 were measured by NMR at 4.2 K. The milling was made from the crystalline intermetallic compounds, inside a cylindrical tool made of hard steel, under argon atmosphere, for several different time intervals. The initial compounds were produced from high purity elements in an arc furnace, under inert atmosphere. Their X-ray diffraction patterns agreed with those of the literature. The milling of Gd Fe 2 and of Gd CO 2 , induces amorphization. Above 1 hour the milling of Gd Fe 2 leads to segregation of α-Fe and formation of a Gd-Fe phase. These results are shown in the X-ray analysis. The spin-echo pulse NMR technique was utilized to study some structural and magnetic as a function of milling time. The measurements were made in a broad band pulse NMR spectrometer. The NMR spectra of the 155 Gd 157 Gd isotopes in Gd Fe 2 show a broadening and displacement of the NMR lines, reflecting the introduction of defects, some kind of disorder and also the formation of a new Gd-rich phase after 1 hour. This result is in agreement with the X-ray spectra. In both systems, the spectra of the amorphous samples show broader lines, and the measured hyperfine fields do not change much with milling. (author). 9 refs., 4 figs

Gd-BOPTA-enhanced excretory MR urography without administration of diuretics; Gd-BOPTA-gestuetzte MR-Ausscheidungsurographie ohne Diuretikagabe

Energy Technology Data Exchange (ETDEWEB)

Allkemper, T.; Tombach, B.; Heindel, W. [Muenster Univ. (Germany). Inst. fuer Klinische Radiologie

2001-02-01

Purpose: To evaluate the feasibility and clinical utility of Gd-BOPTA enhanced excretory magnetic resonance urography without additional administration of diuretics in correlation with conventional urography. Method: 15 preoperative patients with pelvic tumors were examined at 1.5 T using a breath-hold high-resolution 3D-FLASH sequence during first-pass as well as 5, 10, 15 minutes after iv. injection of 0.05 mmol/kg BW Gd-BOPTA (MultiHance {sup trademark}) without administration of diuretics. Post-processed coronal and multiplanar MIP reconstructions were compared to conventional excretory urography with regard to morphologic accuracy, anatomic variability, filling defects, cause and level of obstruction or compression, tumor visibility, and time-effectiveness by two independent radiologists. Results: Visualization of the urinary tract by MRU was comparable to conventional excretory urography in 14 of 15 cases. Caliceal fornices were better delineated on conventional urographies, whereas MRU was considered superior in the assessment of the inferior ureter sections, the urinary bladder and obstructive tumors, whose extents could be clearly marked out. Examination times of both techniques were comparable. Conclusion: These first results show that non-diuretic Gd-BOPTA enhanced MRU is comparable to conventional excretory urography for the preoperative diagnosis of pelvic tumors. Further improvements of this technique seem possible by optimization of examination intervals and injection doses. (orig.) [German] Ziel: Abschaetzung der Durchfuehrbarkeit und des klinischen Nutzens der Gd-BOPTA-gestuetzten MR-Ausscheidungsurographie (MRU) ohne zusaetzliche Diuretikagabe im Vergleich zur konventionellen Ausscheidungsurographie. Methoden: 15 Patienten mit Beckentumoren wurden praeoperativ an einem 1.5 T-Ganzkoerpersystem mit Hilfe einer atemgehaltenen, hochaufloesenden 3D-FLASH-Sequenz unmittelbar nach intra-venoeser Applikation von 0,05 mmol/kg KG Gd-BOPTA (MultiHance {sup

Study of the superdeformed states of the gadolinium nuclei: neutron excitations in {sup 147}Gd nucleus; Etude des etats superdeformes de noyaux de Gadolinium: Excitations neutron dans le noyau {sup 147}Gd

Energy Technology Data Exchange (ETDEWEB)

Khadiri, Najia [Institut de Recherche Subatomique, CNRS-IN2P3 - Universite Louis Pasteur, 67 - Strasbourg (France)

1997-10-17

This work is devoted to nuclear structure studies of superdeformed states in the second potential well. Under focus are the gadolinium isotopes and in particular the {sup 147}Gd nucleus. High spin states in {sup 147}Gd have been populating by {sup 122}Sn ({sup 30}Si,5n){sup 147}Gd fusion-evaporation reaction with a silicon beam of 158 MeV delivered by the VIVITRON accelerator of the Institut de Recherches Subatomiques. The nucleus {gamma} de-excitations have been measured using the EUROGAM II {gamma}-ray multidetector. On the basis of multiple coincidences, four new superdeformed (SD) rotational bands have been assigned to {sup 147}Gd nucleus. Nuclear structures corresponding to these bands have been investigated by shell model calculations using a harmonic oscillator potential with cranking, in the Nilsson Strutinsky formalism. Comparison of dynamical moments of inertia of band (1) and (5) in {sup 147}Gd with {sup 148}Gd(2) and {sup 146}Gd(1) SD bands has fixed the role of the [651 1/2]{alpha} = -1/2 orbital crossing frequency. Theoretical calculations reproduce quite well the {sup 148}Gd(2), {sup 127}Gd(1,5) and G{sup 146}Gd(1) dynamical moments of inertia. Using the particle hole excitation nature of {sup 149,148,147,146}Gd bands, effective spin alignment of [651 1/2]{alpha}= {+-}1/2, [770 1/2]{alpha} = -1/2 and [441 1/2]{alpha} = +1/2 orbitals have been deduced from the experiment in agreement with the theoretical values. Of particular interest, the spin alignment measured for the [441 1/2]{alpha} +1/2 orbital, with a value close to zero, is in contradiction with the value predicted by the Pseudo SU(3) model, formalism often used to explain the identical band phenomenon. (author) 68 refs., 41 figs., 17 tabs.

Thickness dependent formation and properties of GdSi2/Si(100) interfaces

International Nuclear Information System (INIS)

Peto, G.; Molnar, G.; Dozsa, L.; Horvath, Z.E.; Horvath, Zs.J.; Zsoldos, E.; Dimitriadis, C.A.; Papadimitriou, L.

2005-01-01

Epitaxial and polycrystalline orthorhombic GdSi 2 films were grown on Si(100) substrates by solid phase reaction between Si and Gd films at different thicknesses of the Gd film. The most important property of these GdSi 2 /Si interfaces was defect formation. This was investigated by studying the properties of the Schottky barriers by means of current voltage and capacitance-voltage characteristics, deep level transient spectroscopy by double crystal X-ray diffractometry, and transmission electron microscopy. Epitaxial growth of the silicide layer ensured a relatively low interface defect density (about 10 10 cm -2 ), while the non-epitaxial growth induced defects of a much higher density (about 10 12 cm -2 ). The defects generated during the silicide formation are located within a depth of about 10 nm from the GdSi 2 /Si interface. (orig.)

Neutronic analysis of Gd2O3 as burnable poison

International Nuclear Information System (INIS)

Lecot, C.A.

1990-01-01

For the reactors core design, the use of burnable poisons is one of the options for the control of in excess reactivity and the power form factor. As alternative procedures, the absorbing material may be included in pellets of an inert material or in fuel pellets. Besides, a cladding material and the locations of the fuel elements must be chosen for the first case. The CAREM reactor core design foresees the use of gadolinium oxide (Gd 2 O 3 ) as burnable poison. In this work, a comparative study was made, from the neutronic point of view, among the following alternatives for the poisons location: a) Gd 2 O 3 bars supports in alumina (Al 2 O 3 ), sheathed in steel; b) Gd 2 O 3 bars supports in alumina sheathed in Zry-4; c) Gd 2 O 3 in uranium dioxide (UO 2 ) fuel pellets. (Author) [es

Research for magnetocaloric effect of Gd{sub 1-x}Dy{sub x} alloy

Energy Technology Data Exchange (ETDEWEB)

Hou, Xueling; Shitao, Li; An, Zhang; Hui, Xu; Ni, Jiansen; Zhou, Bangxin [Institute of Materials, Shanghai University, Shanghai 20007 (China)

2007-12-15

The magnetocaloric effect (MEC) in Gd{sub 1-x}Dy{sub x} (x=0.13,0.20,0.27,0.34,0.40) alloys is investigated using commercial elements with purity of up to 99.80% for Gd and Dy. These alloys are prepared by arc melting in stoichiometric proportions on a water-cooled copper crucible under high pure argon atmosphere. As a result, when x was changed from 0 to 40at%, the adiabatic temperature change ({delta}T) increases from 1.6 K to 3.1 K, the Curie temperature decreased from 288 K to 245.5 K. Gd{sub 73}Dy{sub 27} exhibits the largest {delta}T{sub max} value of 3.1 K at the T{sub C} value of 260 K among the alloys investigated up to 1.2 T (tesla) applied field, it is almost same as the {delta}T of high pure unitary Gd (99.99%) and is clearly superior to commercial unitary Gd (99.80%). The T{sub C} of Gd{sub 73}Dy{sub 27} alloy is minor to high pure unitary Gd (99.99%) and commercially unitary Gd (99.80%). But this alloy prepared by commercial elements with low cost has better MEC to be a promising candidate for magnetic working substances for room temperature magnetic refrigeration. (copyright 2008 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

MR with GD-DTPA in the diagnosis of spinal lesions

International Nuclear Information System (INIS)

Fenzl, G.; Heywang, S.H.; Vogl, T.

1988-01-01

In spinal lesions GD-DTPA has led to a better diagnosis of tumors concerning the extent and differential diagnosis. Important indications for the application of GD-DTPA are intramedullary tumors: excellent information with respect to extent and differentiation cyst from tumor. At extramedullary interadural tumors we got distinction of extramedullary from intramedullary tumors and more information in the differential diagnosis for example in cases of neurinomas and meningiomas. Additional information is also obtained by means of GD-DTPA in extradural tumors: better delineation from the myelon, better possibilities to differentiate between meningiomas, neurinomas and scar and tumor. (orig.) [de

Valorisation et Recyclage des Déchets Plastiques dans le Béton

Directory of Open Access Journals (Sweden)

Benimam Samir

2014-04-01

Full Text Available La valorisation des déchets dans le génie civil est un secteur important dans la mesure où les produits que l’on souhaite obtenir ne sont pas soumis à des critères de qualité trop rigoureux. Le recyclage des déchets touche deux impacts très importants à savoir l’impact et l’impact économique. Donc plusieurs pays du monde, différents déchets sont utilisé dans le domaine de la construction et spécialement dans le ciment ou béton comme poudre, fibres ou agrégats. Ce travail s’intéresse à la valorisation d’un déchet qui est nuisible pour l’environnement vu son caractère encombrant et inesthétique il s’agit du déchet plastique. Trois types de déchets plastiques sont ajoutés dans le béton (sous forme de grains et fibres (ondulées et rectilignes. Les propriétés à l’état frais (maniabilité, air occlus et densité et à l’état durci (résistance à la compression, à la traction, retrait et absorption d’eau des différents bétons réalisés sont analysées et comparés par rapport leurs témoins respectifs. D’après les résultats expérimentaux on peut conclure que le renforcement de la matrice cimentaire avec des fibres plastiques ondulées montrent une nette amélioration de la résistance à la traction du béton ainsi qu’une diminution remarquable de sa capacité d’absorption de l’eau lorsqu’on utilise des grains plastiques.

Effects of Gd substitution on the structural and magnetic properties of strontium hexaferrites

Energy Technology Data Exchange (ETDEWEB)

Litsardakis, G. [Department of Electrical and Computer Engineering, Aristotle University of Thessaloniki, Thessaloniki 54124 (Greece)]. E-mail: Lits@eng.auth.gr; Manolakis, I. [Department of Electrical and Computer Engineering, Aristotle University of Thessaloniki, Thessaloniki 54124 (Greece); Serletis, C. [Department of Physics, Aristotle University of Thessaloniki, Thessaloniki 54124 (Greece); Efthimiadis, K.G. [Department of Physics, Aristotle University of Thessaloniki, Thessaloniki 54124 (Greece)

2007-09-15

The effect of Gd substitution in M-type strontium hexaferrites has been examined in two series of samples, (Sr{sub 1-x}Gd{sub x})O.5.25Fe{sub 2}O{sub 3} and Sr{sub 1-x}Gd{sub x}Fe{sub 12-x}Co{sub x}O{sub 19}, both prepared by the ceramic method, where x=0-0.40. The samples have been characterized by XRD, VSM and SEM-EDAX techniques. All substituted samples present primarily the hexaferrite structure. Sample (Sr{sub 0.95}Gd{sub x0.05})O.5.25Fe{sub 2}O{sub 3} is single phase. Formation of impurity phases is affected by stoichiometry and presence of Co. In Sr-Gd samples, coercivity showed a maximum value of 305kA/m (3.8kOe) for x=0.20, while remanence and saturation magnetization did not decrease. Coercivity and magnetization in the Sr-Gd-Co series decreased steadily with substitution degree.

Laterally configured resistive switching device based on transition-metal nano-gap electrode on Gd oxide

Energy Technology Data Exchange (ETDEWEB)

Kawakita, Masatoshi; Okabe, Kyota [Department of Physics, Kyushu University, 6-10-1 Hakozaki, Fukuoka 812-8581 (Japan); Kimura, Takashi [Department of Physics, Kyushu University, 6-10-1 Hakozaki, Fukuoka 812-8581 (Japan); Research Center for Quantum Nano-Spin Sciences, Kyushu University, 6-10-1 Hakozaki, Fukuoka 812-8581 (Japan)

2016-01-11

We have developed a fabrication process for a laterally configured resistive switching device based on a Gd oxide. A nano-gap electrode connected by a Gd oxide with the ideal interfaces has been created by adapting the electro-migration method in a metal/GdO{sub x} bilayer system. Bipolar set and reset operations have been clearly observed in the Pt/GdO{sub x} system similarly in the vertical device based on GdO{sub x}. Interestingly, we were able to observe a clear bipolar switching also in a ferromagnetic CoFeB nano-gap electrode with better stability compared to the Pt/GdO{sub x} device. The superior performance of the CoFeB/GdO{sub x} device implies the importance of the spin on the resistive switching.

Surfactant mediated hydrothermal synthesis, characterization and luminescent properties of GdPO{sub 4}: Ce{sup 3+}/Tb{sup 3+} @ GdPO{sub 4} core shell nanorods

Energy Technology Data Exchange (ETDEWEB)

Khajuria, Heena; Ladol, Jigmet; Khajuria, Sonika; Shah, Mohd Syed; Sheikh, H.N., E-mail: hnsheikh@rediffmail.com

2016-08-15

Highlights: • Core shell nanorods were synthesised by surfactant assisted hydrothermal method. • Morphology of core shell nanorods resembles those of core nanorods indicating coating of shell on cores. • More uniform and non-aggregated core shell nanorods were prepared in presence of surfactants. • Surfactant assisted prepared core shell nanorods show intense emission as compared to uncoated core nanorods. - Abstract: Core shell GdPO{sub 4}: Ce{sup 3+}/Tb{sup 3+} @ GdPO{sub 4} nanorods were synthesized via hydrothermal route in the presence of different surfactants [cetyltrimethyl ammonium bromide (CTAB) and Sodium dodecyl sulphate (SDS)]. The nanorods were characterized by powder X-ray diffraction (PXRD), fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS) and photoluminescence (PL) studies. The X-ray diffraction results indicate good crystallinity and effective doping in core and core shell nanorods. SEM and TEM micrographs show that all of the as prepared gadolinium phosphate products have rod like shape. The compositional analysis of GdPO{sub 4}: Ce{sup 3+}/Tb{sup 3+} core was done by EDS. The emission intensity of the GdPO{sub 4}: Ce{sup 3+}/Tb{sup 3+} @ GdPO{sub 4} core shell increased significantly with respect to those of GdPO{sub 4}: Ce{sup 3+}/Tb{sup 3+} core nanorods. The effect of surfactant on the uniformity, thickness and luminescence of the core shell nanorods was investigated.

Canted magnetic moments at the Gd(0001) surface

International Nuclear Information System (INIS)

Li Donggi; Zhang Jiandi; Dowben, P.A.; Tang, H.; Walker, T.G.; Hopster, H.

1993-01-01

With spin polarized electron spectroscopies, the authors have investigated ordered Gd(0001) films deposited on W(110). The photoemission features of the gadolinium 5d surface state, the 4f levels, and the background exhibit considerable spin polarization along the same direction in the plane of the film, indicative of ferromagnetic coupling between the surface and the bulk. The 4f spin polarized photoemission data provides strong evidence that the surface 4f polarization differs from the bulk 4f polarization for Gd(0001). The temperature dependent measurements with spin polarized secondary electron spectroscopy conclusively establishes that the surface of clean Gd(0001) possesses a perpendicular polarization component which persists to an enhanced surface Curie temperature. Small amounts of contamination at the surface result in the disappearance of the perpendicular component and, therefore, a more perfect ferromagnetic coupling between the surface and the bulk

Increase of alcohol yield per ton of pulp

Energy Technology Data Exchange (ETDEWEB)

Sokolov, B N

1957-01-01

Digestion processes of cellulose were studied under production conditions. When the digestion was carried out with acid having 5.2% total SO/sub 2/ and 0.92% CaO, the concentration of total sugars in the spent liquor was 1.8 to 2.5%. When the acidity was reduced to 4.8% total SO/sub 2/ and 0.82% CaO, all other conditions being the same, the sugar concentration in the spent liquor increased to 3.0 to 3.7%. The importance of the acid strength and CaO content of the cooking liquor was further demonstrated at the end of 1955. At that time the total SO/sub 2/ in the acid rose to 8% while the amount of CaO remained practically the same-0.85 to 0.90%. These conditions permitted an increase in the amount of ships by 25 to 30%, which further changed the ratio CaO: wood and created conditions favorable for an improved yield of sugar. The increase in the activity of the acid was reflected favorably in the degree of hydrolysis of the hemicelluloses and in the degree to which the oligosaccharides or polysaccharides were hydrolyzed to simple sugars. At that time the yield of alcohol reached 53 1/ton of unbleached pulp. The process was further improved in 1956 by the use of successive washings; at the end of the digestion period the concentrated spent liquor was piped to the alcohol unit. The yield of alcohol reached 59.4 1/ton of pulp. Sugar recovery from the tank was 92.5% of that theoretically possible. Further improvements resulted by saturating the wood chips with acid under variable pressures. As a result, the base of the cooking acid was reduced to 0.7 to 0.72% and, at the end of the process the liquor contained 0.03 to 0.06% CaO instead of 0.2 to 0.18%. The alcohol yield/ton of pulp then rose to 66.8 l.

Factory Acceptance Test Procedure Westinghouse 100 ton Hydraulic Trailer

International Nuclear Information System (INIS)

Aftanas, B.L.

1994-01-01

This Factory Acceptance Test Procedure (FAT) is for the Westinghouse 100 Ton Hydraulic Trailer. The trailer will be used for the removal of the 101-SY pump. This procedure includes: safety check and safety procedures; pre-operation check out; startup; leveling trailer; functional/proofload test; proofload testing; and rolling load test

Magnetic Susceptibility of liquid Gd-NM (NM = Cu, Ga, Ge alloys

Directory of Open Access Journals (Sweden)

Shimakura Hironori

2017-01-01

Full Text Available For rare earth alloys, the indirect interaction of RKKY is at work between rare-earth atoms. Therefore, the magnetism of them depends on the number of conduction electrons and the distance between rare-earth metals. In this work, to reveal the relationship between the number of conduction electrons and magnetic property of rare earth metal alloys, magnetic susceptibility measurements for liquid Gd-NM (NM = Cu, Ga, Ge was performed by Faraday method. As the results, it was observed that the sign of paramagnetic Curie temperature of Cu-Gd alloys are positive at all composition, while Ga-Gd and Ge-Gd alloys show negative paramagnetic Curie temperature at certain composition. Moreover, it was indicated when the alloy at certain composition shows highest melting temperature, it has the lowest paramagnetic Curie temperature.

ICARUS 600 ton: A status report

CERN Document Server

Vignoli, C; Badertscher, A; Barbieri, E; Benetti, P; Borio di Tigliole, A; Brunetti, R; Bueno, A; Calligarich, E; Campanelli, Mario; Carli, F; Carpanese, C; Cavalli, D; Cavanna, F; Cennini, P; Centro, S; Cesana, A; Chen, C; Chen, Y; Cinquini, C; Cline, D; De Mitri, I; Dolfini, R; Favaretto, D; Ferrari, A; Gigli Berzolari, A; Goudsmit, P; He, K; Huang, X; Li, Z; Lu, F; Ma, J; Mannocchi, G; Mauri, F; Mazza, D; Mazzone, L; Montanari, C; Nurzia, G P; Otwinowski, S; Palamara, O; Pascoli, D; Pepato, A; Periale, L; Petrera, S; Piano Mortari, Giovanni; Piazzoli, A; Picchi, P; Pietropaolo, F; Rancati, T; Rappoldi, A; Raselli, G L; Rebuzzi, D; Revol, J P; Rico, J; Rossella, M; Rossi, C; Rubbia, C; Rubbia, A; Sala, P; Scannicchio, D; Sergiampietri, F; Suzuki, S; Terrani, M; Ventura, S; Verdecchia, M; Wang, H; Woo, J; Xu, G; Xu, Z; Zhang, C; Zhang, Q; Zheng, S

2000-01-01

The goal of the ICARUS Project is the installation of a multi-kiloton LAr TPC in the underground Gran Sasso Laboratory. The programme foresees the realization of the detector in a modular way. The first step is the construction of a 600 ton module which is now at an advanced phase. It will be mounted and tested in Pavia in one year and then it will be moved to Gran Sasso for the final operation. The major cryogenic and purification systems and the mechanical components of the detector have been constructed and tested in a 10 m3 prototype. The results of these tests are here summarized.

Development of long GdBCO coated conductor using the IBAD/MPMT-PLD method

International Nuclear Information System (INIS)

Ibi, A; Fukushima, H; Yamada, Y; Miyata, S; Kuriki, R; Takahashi, K; Shiohara, Y

2006-01-01

We have developed long GdBa 2 Cu 3 O 7-X (GdBCO) coated conductors by a multi-plume and multi-turn pulsed laser deposition (MPMT-PLD) method and have successfully fabricated 32 and 60.7 m long GdBCO coated conductors with a high critical current, I c , and high deposition rate. The I c of the 32 and 60.7 m long GdBCO coated conductors were 205 A (J c = 1.36 MA cm -2 ) and 183 A (J c = 1.45 MA cm -2 ), respectively, at 77 K and 0 T. In addition, they exhibited higher I c values in a magnetic field than a YBa 2 Cu 3 O 7-X (YBCO) coated conductor: typically 20 A at 77 K and 3 T while the value for a YBCO coated conductor is 8 A. These high I c values are due to the smaller number of a-axis oriented grains in GdBCO than in YBCO. Furthermore, the speed of production of the GdBCO layer was increased to 10 m h -1 while that of the former YBCO coated conductor was 3.75 m h -1 . The material yield of long GdBCO layers using the MPMT-PLD method was about 26-28%. The high I c of GdBCO in a magnetic field, the high production rate and the high material yield are promising for applications

Implications of\tenhanced\teffectiveness\tof\tvincristine\tsulfate/ε-viniferin combination\tcompared\tto\tvincristine\tsulfate\tonly\ton\tHepG2\tcells

Directory of Open Access Journals (Sweden)

Filiz\tÖzdemir

2016-12-01

Full Text Available Objective: This\tstudy\twas\tdesigned\tto\tinvestigate\tthe\teffects\tof\tε-viniferin\t(ε-VNF\ton\tthe\tmitochondrial\tpathway\tof\tapoptosis and\ton\tlate\tapoptosis\tin\tHepG2\tcell\tlines.\tTo\tobserve\tthese\teffects,\tε-VNF\tand\tvincristine\tsulfate\t(VNC,\tanti-cancer\tdrugs\tused for\ttreatment\ton\tHepG2\tcells,\twere\tadministered\teither\talone\tor\tin\tcombination\tat\tdifferent\ttime\tintervals. Methods:\tMitochondrial\tmembrane\tpotential\tchanges\tin\tthe\tcells\t(ΔΨm\twere\tevaluated\tusing\tcationic\tdye\tJC-1,\twhile\tBax,\tBcl- 2\texpression\tlevels\twith\tRT-PCR\tand\tcaspase-3\tactivity\twere\tanalyzed\tusing\ta\tkit.\tFor\tdetection\tof\tapoptotic\tactivity,\tan\tin\tsitu TUNEL\tassay\twas\tperformed. Results: When 98.3µM ε-VNF, 52.5µM VNC and the 11.25+15.8µM VNC+ε-VNF combination were compared with the control group,\tΔΨm\tchanges\tat\tthe\t6th\thour\twere\tfound\tto\tbe\t19.5%,\t5.5%,\t24.6%,\tand\t3.5%\t,\trespectively.\tThese\tfinding\tshow\tthat\tthe combination\tgroup\t(24.6%\tresulted\tin\tearly\tapoptosis\tof\tthe\tcell\tat\tthe\t6th\thour.\tBax\tmRNA\texpression\tincreased\tat\tthe\t24th hour in the VNC+ε-VNF group compared to control group (160%, and caspase-3 activation increased in the 1.25+15.8 µM[VNC+ε-VNF]\tgroup\tcompared\tto\tthe\tcontrol\tgroup\tat\tthe\t48th\thour.\tThe\tdetection\tof\tDNA\tfragments\tin\tHepG2\tcells\twithin 24\thours\tsuggests\tdirect\tapoptosis. Conclusion: These findings demonstrate that the doses administered to the VNC+ε-VNF combination group\twere\tlower than those\tadministered\tto\tgroups\tusing\tone\tagent\talone\t(e.g.\tVNC,\tthe\tresults\tof\twhich\treduce\tthe\tpossibility\tof\tadministering\ttoxic doses.

10'000 ton ALICE gets her UK-built "Brain"

CERN Multimedia

Maddock, Julia

2007-01-01

For one of the four LEP experiments, called ALICE, the process got a step closer last week when a crucial part of the 10'000-ton detector, the British-built Central Trigger Processor (CTP), was installed in the ALICE cavern, some 150 feet underground. (plus background information about ALICE) (2,5 pages)

Fuel densification study about uranium- 7% nanostructured gadolinium (Gd{sub 2}O{sub 3}); Estudo da densificacao do combustivel uranio - 7% gadolinio (Gd{sub 2}O{sub 3}) nanoestruturado

Energy Technology Data Exchange (ETDEWEB)

Serafim, Antonio da Costa

2016-11-01

The sintering process of UO{sub 2}-Gd{sub 2}O{sub 3} pellets has been investigated in this work for its importance in the nuclear industry and for its complex behavior during sintering. Sintering blockage occurs from 1300 deg C upwards, when densification is shifted toward higher temperatures and the final density obtained is decreased. This research includes the development of nuclear fuel for power reactors in order to increase its efficiency inside the reactor core by raising the burnup. The use of nanosized Gd{sub 2}O{sub 3} was studied in the range from 10 to 30nm, which was added to UO{sub 2}, trying to verify the occurrence of characteristic sintering blockage due to Kirkendall sintering effect observed in previous research. The samples were produced by dry mechanical mixture of UO{sub 2} powder and 7% Gd{sub 2}O{sub 3} (macro- and nanostructured). The powders were compacted and the pellets were sintered at 1700 deg C under H{sub 2} atmosphere. These results indicate that the characteristic blockage during sintering in macrostructured system UO{sub 2}-Gd{sub 2}O{sub 3} occurred in the temperature range of 1300-1500 deg C, which slows down the densification. It was observed a less intense effect when using the nanostructured Gd{sub 2}O{sub 3}; it took place at the temperature of 900 deg C, then facilitating to get an additional densification. The dilatometric tests indicated shrinkage of 22, 18 and 20% respectively in UO{sub 2} pellets, macrostructured UO{sub 2}-7% Gd{sub 2}O{sub 3} and nanostructured UO{sub 2}-7%Gd{sub 2}O{sub 3}. We detected 2% higher shrinkage, when nanostructured Gd{sub 2}O{sub 3} was used instead of macrostructured Gd{sub 2}O{sub 3}, which is used commercially. Then, the nanostructured results showed more adequate density for nuclear fuel usage. (author)

Ferro-paramagnetic coupled resonant modes in GdEuCuO4

International Nuclear Information System (INIS)

Fainstein, A.; Tovar, M.

1990-01-01

Two paramagnetic resonances were observed in compound GdEuCuO 4 : one was originated in trivalent gadolinium paramagnetism, while the other is associated to a weak ferromagnetic mode in Cu-O planes. In this work, experimental results are presented that show an anisotropy and a strongly anomalous temperature dependence of Gd 3+ . A theoretical model was introduced which explains the data in terms of coupled ferro-paramagnetic resonant modes originated in spin exchange coupling of Cu and Gd. (Author). 9 refs., 4 figs

Study on factors affecting sintering density of Gd2O3-UO2 pellets

International Nuclear Information System (INIS)

Zhu Shuming; Zou Congpei; Yang Jing; Yang Youqing; Mei Xiaohui

1996-02-01

The sintered density of Gd 2 O 3 -UO 2 burnable poison fuel pellets is an important quality index and is one of main QC items. Therefore, the efforts were made to investigate the factors affecting the sintered density of Gd 2 O 3 -UO 2 , that is, the influences of pre-treatment of Gd 2 O 3 powder, additives, mixing methods and time, sintering atmosphere, sintering temperature and time on the final density of Gd 2 O 3 UO 2 pellets contained 0, 3%, 7% and 10% (mass percentage) Gd 2 O 3 . The results show: the pre-treatment is useful for improving the distribution of Gd 2 O 3 ; the additive of ammonium oxalate will effectively adjust the density of pellets; 1750 degree C is the suitable sintering temperature. The proper process parameters have been obtained, and the Gd 2 O 3 -UO 2 pellets prepared for in-pile irradiation test meet the design requirements for the density (93.5%∼96.5% of T.D.), homogeneity, microstructure, etc. (8 refs., 3 figs., 8 tabs.)

Neutronics feasibility of using Gd2O3 particles in VVER-1000 fuel assembly

International Nuclear Information System (INIS)

Hoang Van Khanh; Hoang Thanh Phi Hung; Tran Hoai Nam

2016-01-01

Neutronics feasibility of using Gd 2 O 3 particles for controlling excess reactivity of VVER-1000 fuel assembly has been investigated. The motivation is that the use of Gd 2 O 3 particles would increase the thermal conductivity of the UO 2 +Gd 2 O 3 fuel pellet which is one of the desirable characteristics for designing future high burnup fuel. The calculation results show that the Gd 2 O 3 particles with the diameter of 60 µm could control the reactivity similarly to that of homogeneous mixture with the same amount of Gd 2 O 3 . The power densities at the fuel pin with Gd 2 O 3 particles increase by about 10-11%, leading to the decrease of the power peak and a slightly flatter power distribution. The power peak appears at the periphery pins at the beginning of burnup process which is decreased by 0.9 % when using Gd 2 O 3 particles. Further work and improvement are being planned to optimize the high power peaking at the beginning of burnup. (author)

Development of a compact superconducting magnet with a GdBCO magnetic lens

International Nuclear Information System (INIS)

Zhang, Z Y; Matsumoto, S; Kiyoshi, T; Teranishi, R

2013-01-01

Concentration of a magnetic field has been achieved using a Gd–Ba–Cu–O (GdBCO) magnetic lens. A conduction-cooled compact high-field superconducting magnet with a GdBCO magnetic lens was developed. The magnet possessed a 10-mm room-temperature bore and consisted of two Nb–Ti solenoid coils and a GdBCO magnetic lens, which was installed at the center of the Nb–Ti coils in order to concentrate the background field generated by the Nb–Ti coils. The Nb–Ti coils and the GdBCO magnetic lens were cooled using a two-stage pulse-tube cryocooler. A concentrated magnetic field of 10.3 T was obtained at a background field of 5.6 T provided by the Nb–Ti coils. No degradation was found in the magnet during repeat excitation. The large field gradient generated by the GdBCO magnetic lens is expected to be used for the levitation of diamagnetic materials. (paper)

Comportement en flexion des bétons fibrés sous chargement cyclique

Directory of Open Access Journals (Sweden)

Boulekbache Bensaid

2014-04-01

Full Text Available Ce papier présente les résultats d’une étude expérimentale sur le comportement en flexion des bétons de fibres métalliques. On étudie l’effet de la rhéologie du béton sur l’orientation des fibres et l’influence de l’orientation sur les propriétés mécaniques. La rigidité de l’ancrage des fibres étudiée par les essais cycliques est liée aux caractéristiques rhéologiques et mécaniques de la matrice. Les résultats montrent que la fluidité des bétons est un paramètre essentiel de l’orientation des fibres. Dès lors que l’on obtient une orientation dans le sens de l’efficacité mécanique, la résistance à la flexion est nettement améliorée.

Synthesis of nanocrystalline Gd{sub 2}O{sub 2}NCN from a versatile single-source precursor

Energy Technology Data Exchange (ETDEWEB)

Ionescu, Emanuel; Wiehl, Leonore; Mera, Gabriela; Riedel, Ralf [Fachbereich Material- und Geowissenschaften, Technische Universitaet Darmstadt (Germany); Li, Wenjie [Fachbereich Material- und Geowissenschaften, Technische Universitaet Darmstadt (Germany); Center for Energy Harvesting Materials and Systems, Mechanical Engineering Department, Virginia Polytechnic Institute and State University, Blacksburg, VA (United States)

2017-11-17

Nanocrystalline Gd{sub 2}O{sub 2}NCN (P anti 3m1, crystallite size 30-40 nm) was synthesized upon ammonolysis of bis[[(N-carboxymethyl,N-carboxy-κO-methyl)amino-κN-ethyl]-glycinato( 3-)-κN,κO]gadolinium(III) (diethylenetriamine pentaacetic acid gadolinium(III) dihydrogen salt or gadopentetic acid, Gd-H{sub 2}DTPA hereafter) at 900 C. The conversion of Gd-H{sub 2}DTPA into Gd{sub 2}O{sub 2}NCN takes place in several steps, probably via transient formation of iminodiacetate-, glycinate-, and carbamate-containing complexes of Gd. Thermal treatment in air of Gd-H{sub 2}DTPA at 750 and 1300 C delivers nanocrystalline bixbyite-type Gd{sub 2}O{sub 3} (Ia anti 3, crystallite size 30-70 nm); in an argon or nitrogen atmosphere the formation of monoclinic Gd{sub 2}O{sub 3} (C2/m) was observed at 1300 C. The synthesized Gd{sub 2}O{sub 2}NCN converts upon thermal treatment in air, nitrogen, or argon atmosphere into monoclinic Gd{sub 2}O{sub 3} (C2/m). In ammonia atmosphere, Gd{sub 2}O{sub 2}NCN seems to be stable against decomposition, even upon prolonged exposure to 1000 C. This study indicates that Gd-H{sub 2}DTPA may be a robust, low-cost, and flexible precursor for nanoscaled Gd-based nanopowders. Moreover, precursor approaches based on metal complexes using H{sub 5}DTPA as a ligand are suggested as promising access pathways towards nanocrystalline materials in the M/O/C/N system. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Gd2O3 nanoparticles stabilized by hydrothermally modified dextrose for positive contrast magnetic resonance imaging

Science.gov (United States)

Babić-Stojić, Branka; Jokanović, Vukoman; Milivojević, Dušan; Požek, Miroslav; Jagličić, Zvonko; Makovec, Darko; Arsikin, Katarina; Paunović, Verica

2016-04-01

Gd2O3 nanoparticles of a few nm in size and their agglomerates dispersed in dextrose derived polymer template were synthesized by hydrothermal treatment. The produced nanosized material was investigated by TEM, FTIR spectroscopy, SQUID measurements and NMR relaxometry. Biological evaluation of this material was done by crystal violet and MTT assays to determine the cell viability. Longitudinal and transverse NMR relaxivities of water diluted Gd2O3 nanoparticle dispersions measured at the magnetic field of 1.5 T, estimated to be r1(Gd2O3)=9.6 s-1 mM-1 in the Gd concentration range 0.1-30 mM and r2(Gd2O3)=17.7 s-1 mM-1 in the lower concentration range 0.1-0.8 mM, are significantly higher than the corresponding relaxivities measured for the standard contrast agent r1(Gd-DTPA)=4.1 s-1 mM-1 and r2(Gd-DTPA)=5.1 s-1 mM-1. The ratio of the two relaxivities for Gd2O3 nanoparticles r2/r1=1.8 is suitable for T1-weighted imaging. Good MRI signal intensities of the water diluted Gd2O3 nanoparticle dispersions were recorded at lower Gd concentrations 0.2-0.8 mM. The Gd2O3 samples did not exert any significant cytotoxic effects at Gd concentrations of 0.2 mM and below. These properties of the produced Gd2O3 nanoparticles in hydrothermally modified dextrose make them promising for potential application in MRI for the design of a positive MRI contrast agent.

Crystallographic and 119Sn and 155Gd Moessbauer analyses of Gd5Ge2(Si1-xSnx)2 (x = 0.23 and x = 0.40)

International Nuclear Information System (INIS)

Campoy, J. C. P.; Santos, A. O. dos; Cardoso, L. P.; Paesano, A.; Raposo, M. T.; Fabris, J. D.

2010-01-01

We report the structural characterization of Gd 5 Ge 2 (Si 1-x Sn x ) 2 (x = 0.23 and x = 0.40) compounds by means of 100 and 298 K-X-ray diffractometry (XRD) and 4 K- 155 Gd and 298 K- 119 Sn Moessbauer spectroscopy. These compounds order ferromagnetically at 218.4 and 172.7 K, respectively. At ∼100 K, it was identified the Gd 5 Si 4 -orthorhombic phase (type I) for both samples. At ∼298 K, it was identified a Gd 5 Si 2 Ge 2 -monoclinic phase, for x = 0.23 and a Sm 5 Sn 4 -orthorhombic phase (type II), for x 0.40. The Rietveld analysis of XRD data suggests a first order magneto-structural transition at Curie temperature for both compositions. Moessbauer results are well consistent with the proposed crystallographic models for these systems.

An aging effect and its origin in GdBCO thin films

Science.gov (United States)

Schlesier, K.; Huhtinen, H.; Granroth, S.; Paturi, P.

2010-06-01

An aging effect investigation was made for GdBa2Cu3O7 (GdBCO) thin films grown on SrTiO3 (001) substrates with pulsed laser deposition (PLD) method from nanograined targets. The films were cut into two pieces where one piece was coated with gold cap layer while the other was left without coating. Both pieces were kept in ambient air during the half year measurement period. Magnetization measurements as well as phase purity, lattice parameter, oxygen effect and depth structure determination with x-ray diffraction (XRD) were made in one month interval. For structure and oxygen content, x-ray photoelectron spectroscopy measurements (XPS) were done in the beginning and in the end of the period. A reduction of the critical temperature and the critical current density, Jc, was found in the gold coated GdBCO film in ambient air in course of time. A smaller decrease of Jc was detected in uncoated GdBCO. No development of impurity phase, increase of a-orientation or reduction of the pinning structure was detected in uncoated GdBCO. However, a small development of impurity phase was found in gold coated GdBCO. The diminution of Tc and Jc is concluded to originate from oxygen release. No such a phenomenon was found in YBa2Cu3O7. We conclude that gold is not a proper cap layer at least for some applications.

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.

MR enhancement of epidural fibrosis by Gd-DTPA: Biodistribution and mechanism

International Nuclear Information System (INIS)

Ross, J.S.; Delamater, R.; Van Dyke, C.W.; Masaryk, T.J.; Hueftle, M.G.; Bohlman, H.; Modic, M.T.

1987-01-01

Epidural lumbar fibrosis was induced in eight beagle dogs at the L-6 level. Vascular injection with india ink showed abundant vessels in the scar. This agreed with light microscopy in eight patients with epidural fibrosis, which enhanced with Gd-DTPA from a clinical trial. Electron microscopy of epidural scar in humans and dogs demonstrated a continuous endothelium with scattered tight junctions. Biodistirbution was determined in four dogs with rapid MR scanning following intravenous (IV) bolus of 0.1 mmol/kg of Gd-DTPA and radioassay of tissue samples following Gd-153-DTPA IV injection. Maximum percent enhancement (70% humans, 100% dogs) occurred at 3-6 minutes in epidural fibrosis with a slow decline in enhancement over the next hour. These findings suggest that Gd-DTPA enhancement of epidural fibrosis is via an extracellular distribution within vascularized scar tissue

Effective combination treatment of GD2-expressing neuroblastoma and Ewing's sarcoma using anti-GD2 ch14.18/CHO antibody with Vγ9Vδ2+ γδT cells.

Science.gov (United States)

Fisher, Jonathan P H; Flutter, Barry; Wesemann, Florian; Frosch, Jennifer; Rossig, Claudia; Gustafsson, Kenth; Anderson, John

Gamma delta T lymphocytes (γδT cells) have pleiotropic properties including innate cytotoxicity, which make them attractive effectors for cancer immunotherapy. Combination treatment with zoledronic acid and IL-2 can activate and expand the most common subset of blood γδT, which express the Vγ9Vδ2 T cell receptor (TCR) (Vδ2 T cells). Vγ9Vδ2 T cells are equipped for antibody-dependent cell-mediated cytotoxicity (ADCC) through expression of the low-affinity FcγR CD16. GD2 is a highly ranked tumor associated antigen for immunotherapy due to bright expression on the cell surface, absent expression on normal tissues and availability of therapeutic antibodies with known efficacy in neuroblastoma. To explore the hypothesis that zoledronic acid, IL-2 and anti-GD2 antibodies will synergize in a therapeutic combination, we evaluated in vitro cytotoxicity and tumor growth inhibition in the GD2 expressing cancers neuroblastoma and Ewing's sarcoma. Vδ2 T cells exert ADCC against GD2-expressing Ewing's sarcoma and neuroblastoma cell lines, an effect which correlates with the brightness of GD2 expression. In an immunodeficient mouse model of small established GD2-expressing Ewing's sarcoma or neuroblastoma tumors, the combination of adoptively transferred Vδ2+ T cells, expanded in vitro with zoledronic acid and IL-2, with anti-GD2 antibody ch14.18/CHO, and with systemic zoledronic acid, significantly suppressed tumor growth compared to antibody or γδT cell-free controls. Combination treatment using ch14.18/CHO, zoledronic acid and IL-2 is more effective than their use in isolation. The already-established safety profiles of these agents make testing of the combination in GD2 positive cancers such as neuroblastoma or Ewing's sarcoma both rational and feasible.

Initial operational experience with Gd-2M+ fuel at Dukovany NPP

International Nuclear Information System (INIS)

Borovička, M.; Zýbal, J.

2015-01-01

Trend of continuous development of nuclear fuel and fuel cycle can be observed from the very beginning of Dukovany NPP operation. The results of this development are documented on the one hand by extending the length of the cycle and on the other by significant reduction in the number of fresh FA’s which are loaded into reactor cores. As a continuation of this trend introduces Dukovany NPP evolutional change of nuclear fuel from the fuel Gd-2M to the Gd-2M + . (authors) Keywords: Gd-2M + , fuel assembly, operational experience

Applied molecular simulations over FER-, TON- and AEL-type zeolites

NARCIS (Netherlands)

Domokos, L.; Lefferts, Leonardus; Seshan, Kulathuiyer; Lercher, J.A.

2001-01-01

Interaction and transport of representative (un)saturated hydrocarbon molecules involved in the proposed reaction network of n-butene isomerization in zeolites FER, TON, and AEL have been studied by classic molecular modeling calculations. Docking of the guest molecules into the zeolite frameworks

X-ray excited photoluminescence near the giant resonance in solid-solution Gd1-xTbxOCl nanocrystals and their retention upon solvothermal topotactic transformation to Gd1-xTbxF3

Science.gov (United States)

Waetzig, Gregory R.; Horrocks, Gregory A.; Jude, Joshua W.; Zuin, Lucia; Banerjee, Sarbajit

2015-12-01

Design rules for X-ray phosphors are much less established as compared to their optically stimulated counterparts owing to the absence of a detailed understanding of sensitization mechanisms, activation pathways and recombination channels upon high-energy excitation. Here, we demonstrate a pronounced modulation of the X-ray excited photoluminescence of Tb3+ centers upon excitation in proximity to the giant resonance of the host Gd3+ ions in solid-solution Gd1-xTbxOCl nanocrystals prepared by a non-hydrolytic cross-coupling method. The strong suppression of X-ray excited optical luminescence at the giant resonance suggests a change in mechanism from multiple exciton generation to single thermal exciton formation and Auger decay processes. The solid-solution Gd1-xTbxOCl nanocrystals are further topotactically transformed with retention of a nine-coordinated cation environment to solid-solution Gd1-xTbxF3 nanocrystals upon solvothermal treatment with XeF2. The metastable hexagonal phase of GdF3 can be stabilized at room temperature through this topotactic approach and is transformed subsequently to the orthorhombic phase. The fluoride nanocrystals indicate an analogous but blue-shifted modulation of the X-ray excited optical luminescence of the Tb3+ centers upon X-ray excitation near the giant resonance of the host Gd3+ ions.Design rules for X-ray phosphors are much less established as compared to their optically stimulated counterparts owing to the absence of a detailed understanding of sensitization mechanisms, activation pathways and recombination channels upon high-energy excitation. Here, we demonstrate a pronounced modulation of the X-ray excited photoluminescence of Tb3+ centers upon excitation in proximity to the giant resonance of the host Gd3+ ions in solid-solution Gd1-xTbxOCl nanocrystals prepared by a non-hydrolytic cross-coupling method. The strong suppression of X-ray excited optical luminescence at the giant resonance suggests a change in mechanism

/GD-Tracker/ A software for blood-brain barrier permeability assessment\

Czech Academy of Sciences Publication Activity Database

Kala, David; Svoboda, Jan; Litvinec, Andrej; Pošusta, Antonín; Lisý, J.; Šulc, V.; Tomek, A.; Marusič, P.; Jiruška, Přemysl; Otáhal, Jakub

2017-01-01

Roč. 47, č. 2 (2017), s. 43-48 ISSN 0301-5491 R&D Projects: GA MZd(CZ) NV15-33115A; GA MŠk(CZ) LM2015062 Institutional support: RVO:67985823 Keywords : blood-brain barrier * MRI * Gd-DTPA * permeability * stroke * epileptogenesis * MATLAB * freeware * Gd-Tracker Subject RIV: FH - Neurology OBOR OECD: Neurosciences (including psychophysiology

Influence of Gd2O3 on thermal and spectroscopic properties of aluminosilicate glasses

Science.gov (United States)

Kasprzyk, Marta; Środa, Marcin

2018-06-01

A series of aluminosilicate glasses 25SiO2·(20-x)Al2O3·40Na2O·15BaO-xGd2O3 with 0 ≤ x ≤ 10 were prepared in order to analyze the influence of gadolinium on thermal and spectroscopic properties of these materials. Increasing of thermal parameters (Tg, Tx, Δcp, ΔT) values with higher Gd2O3 content was determined using DSC method. Crystalline phases, formed during heat treatment, were identified with XRD - NaAlSiO4 and BaSiO3 in glass with 0% mol. Gd2O3 and Gd9.33(SiO4)6O2, NaAlSiO4 and BaAl2Si2O6 in glass with 10% mol. Gd2O3. Spectroscopic analysis - FTIR and Raman - revealed Gd2O3 influence on glass structure in the same way like Al2O3, but some differences appear due to the differ bond strength and ionic radius between Gd and Al. Raman spectra confirmed higher network polymerization (enriched with Q2 units). Optical band gap energy (Eopt) and Urbach energy (ΔE) were calculated from the Tauc plot. Mechanical tests demonstrated lower microhardness with increasing content of Gd2O3 content, as a result of higher concentration of atoms with larger radius.

A comparative study on the luminescence properties of Ce3+/Tb3+ doped Gd-based host nanomaterials

Science.gov (United States)

Jadhao, Charushila Vasant; Rani, Barkha; Sahu, Niroj Kumar

2018-04-01

A comparative study on the crystal phases and their respective luminescence behaviour of Gd3+ based host materials such as GdPO4, GdF3, GdVO4 and Gd2O3 sensitized with 7at.% Ce3+ and activated with 5 at.% Tb3+ have been reported. The nanomaterials were prepared by polyol method using ethylene glycol as solvent and found to have different crystal structures such as monoclinic, orthorhombic, tetragonal and cubic phase. Clear characteristics emission from Tb3+ has been observed in all the samples when excited in the absorption wavelength of Ce3+ and Gd3+ (˜280 nm). Among all the above materials, intense emission of Tb3+ is found in GdPO4 followed by GdF3, Gd2O3 and GdVO4 respectively. The Tb3+ emission is strongly influenced by the energy transfer process and crystal structure of the host materials and hence this study will be important for choosing suitable materials for display devices and biomedical applications.

Solution growth of the Gd-Cu-Al systems in the low-gadolinium concentration range

International Nuclear Information System (INIS)

Uhlirova, Klara; Sechovsky, Vladimir

2009-01-01

Solution growth of Gd-Cu-Al resulted in the formation of single crystals of GdCu 4 Al 8 with tetragonal ThMn 12 -type structure (a = 8.751 Aa, c = 5.148 Aa), Gd 2 Cu 9.4-6.7 Al 7.6-10.3 with hexagonal Th 2 Zn 17 -type structure (a = 8.83 Aa c = 1.28 Aa), and Gd(Cu, Al) 4 with orthorhombic CeNi 2+x Sb 2-x -type structure. An antiferromagnetic ordering of GdCu 4 Al 8 was found below 35 K, which is in agreement with the previously reported T N = 35 K and T N = 32 K measured on polycrystalline samples. In the temperature range 50-320 K the magnetic susceptibility χ follows the Curie-Weiss law with μ eff = 7.8 μ B /f.u. and θ p = -17 K for B parallel c, μ eff = 7.9 μ B /f.u. and θ p = - 18 K for B perpendicular to c. The a-axis is the easy magnetization direction. The Gd(Cu, Al) 4 and Gd(Cu, Al) 4 compounds order antiferromagnetically below T N = 35 K and T N = 31 K, respectively. (orig.)

Safety aspects of the using Gd as burnable poison in PWR's

International Nuclear Information System (INIS)

Vandenberg, C.; Bonet, H.; Charlier, A.

1978-01-01

The experience of BELGONUCLEAIRE in using Gd in LWR's has indicated the safety related advantages of this burnable poison. The successfully operation of the BR3 PWR power plant with 5% of Gd rods is presented and extrapolated to large PWR's. (authro)

Follow-up of acute myocardial infarction with Gd-DTPA-enhanced MR image

International Nuclear Information System (INIS)

Matheijssen, N.A.A.; Dijkman, P.; Rossum, A.C. van der; Laarse, A. van der; Voorthuisen, A. van; Bruschke, A.

1990-01-01

MR imaging with Gd-DTPA has been shown to be useful in the identification of acutely infarcted myocardium. The purpose of this paper is to assess the influence of Gd-DTPA on myocardial signal intensity (SI) at different intervals after acute myocardial infarction (SMI). The authors used Gd-DTPA-enhanced MR imaging to study 84 patients at different intervals after AMI. A total of 109 T1-weighted MR studies were performed with a Philips Gyroscan magnet (0.5T) before and 20 minutes after Gd-DTPA (0.15 mmol/kg given intravenously). Four groups were studied. Group 1 underwent MR imaging less than 1 week after AMI; group 2, 1-3 weeks; group 3, 3-6 weeks; and group 4, over 6 weeks after AMI

Apparent suppression of MMP-9 activity by GD1a as determined by gelatin zymography.

Science.gov (United States)

Hu, Dan; Tan, Xuan; Sato, Toshinori; Yamagata, Sadako; Yamagata, Tatsuya

2006-10-13

Gelatin zymography is widely used to detect and evaluate matrix metalloproteinase-9 (MMP-9) activity. MMP-9 transcription was previously shown to be negatively regulated by ganglioside GD1a [D. Hu, Z. Man, T. Xuan, P. Wang, T. Takaku, S. Hyuga, X.S. Yao, T. Sato, S. Yamagata, T. Yamagata, Ganglioside GD1a regulation of matrix metalloproteinase-9 (MMP-9) expression in mouse FBJ cell Lines: GD1a suppression of MMP-9 expression stimulated by PI3K-Akt and p38 though not by the Erk signaling pathway, 2006, submitted for publication.]. Zymography of MMP-9 of FBJ-M5 cells preincubated with GD1a indicated a greater decrease in activity than expected from mRNA suppression. Incubation of conditioned medium containing MMP-9 with GD1a caused MMP-9 activity to decrease. Examination was thus made to confirm that MMP-9 activity is actually suppressed and/or MMP-9 protein undergoes degradation by GD1a. GD1a was found to have no effect on MMP-9 activity and Western blots indicated GD1a not to diminish MMP-9 during electrophoresis under reducing conditions. GD1a appeared to mediate the binding of a portion of MMP-9 with certain molecules, with consequently greater molecular mass on the gel, to cause decrease in the activity of MMP-9 at the site where it would normally appear. Caution should be used in doing gelatin zymography since molecules other than GD1a may similarly work, causing decrease in MMP-9 activity in zymography.

Organic and Inorganic Fertilizers Application on NPK Uptake and Production of Sweet Corn in Inceptisol Soil of Lowland Swamp Area

Directory of Open Access Journals (Sweden)

Marlina Neni

2017-01-01

Full Text Available This study objective was to determine the dose of organic and inorganic fertilizers which can increase N, P and K nutrients uptake as well as the growth and yield of sweet corn on inceptisol soil of lowland swamp. Inceptisol soil has low soil fertility and relatively low to moderate levels of organic matter content. Application of organic fertilizer on inceptisol soil of lowland swampis expected capable to increase N, P and K nutrients as well as yield of sweet corn. This research was conducted from April to July 2014 at Experimental Farm Area of Pulau Semambu Village, Indralaya Utara Subdistrict, Ogan Ilir District, South Sumatra Province. The method used in this research was randomized block design consisting treatments as follows: 75% inorganic fertilizer + 5 ton.ha−1organic fertilizer, 50% inorganic fertilizer + 5 ton.ha−1organic fertilizer, 25% inorganic fertilizer + 5 ton.ha−1 organic fertilizer, 0% inorganic fertilizer + 5 ton.ha−1organic fertilizer with six replications. The recommended dose of inorganic fertilizerswas 200 kg.ha−1 urea, 100 kg.ha−1 SP-36 and 100 kg. ha−1 KCl. The results showed that treatment of 75% of inorganic fertilizer + 5 ton.ha−1organic fertilizer had produced N, P and K nutrients uptake with magnitude of 1.850, 0.418 and 2.374 g.plant−1 respectively as well as good growth and yield of sweet corn with magnitude of 356.36 g. plant−1or 15.21 ton ha−1.

In vitro photothermal destruction of neuroblastoma cells using carbon nanotubes conjugated with GD2 monoclonal antibody

International Nuclear Information System (INIS)

Wang, Chung-Hao; Huang, Yao-Jhang; Chang, Chia-Wei; Peng, Ching-An; Hsu, Wen-Ming

2009-01-01

Despite aggressive multimodality therapy, most neuroblastoma-bearing patients relapse and survival rate remains poor. Exploration of alternative therapeutic modalities is needed. Carbon nanotubes (CNTs), revealing optical absorbance in the near-infrared region, warrant their merits in photothermal therapy. In order to specifically target disialoganglioside (GD2) overexpressed on the surface of neuroblastoma stNB-V1 cells, GD2 monoclonal antibody (anti-GD2) was conjugated to acidified CNTs. To examine the fate of anti-GD2 bound CNTs after incubation with stNB-V1 cells, rhodamine B was labeled on carboxylated CNTs functionalized with and without anti-GD2. Our results illustrated that anti-GD2-linked CNTs were extensively internalized by neuroblastoma cells via GD2-mediated endocytosis. In addition, we showed that anti-GD2 bound CNTs were not ingested by PC12 cells without GD2 expression. After anti-GD2 conjugated CNTs were incubated with neuroblastoma cells for 6 h and endocytosed by the cells, CNT-laden neuroblastoma cells were further irradiated with an 808 nm near-infrared (NIR) laser with intensity ramping from 0.6 to 6 W cm -2 for 10 min which was then maintained at 6 W cm -2 for an additional 5 min. Post-NIR laser exposure, and after being examined by calcein-AM dye, stNB-V1 cells were all found to undergo necrosis, while non-GD2 expressing PC12 cells all remained viable. Based on the in vitro study, CNTs bound with anti-GD2 have the potential to be utilized as a therapeutic thermal coupling agent that generates heat sufficient to selectively kill neuroblastoma cells under NIR laser light exposure.

Phosphors doped with Dy3+ and Gd3+ for lighting

International Nuclear Information System (INIS)

Su, Q; Pei, Z.; Zeng, Q.; Chi, L.

1998-01-01

Full text: Some heavy lanthanide ions with even atomic number such as Dy 3+ and Gd 3+ are abundant in the ion adsorption type deposit of China. Their price is cheap and they have specific spectroscopic properties which can be used as phosphors. Dy 3i on has two dominant bands in the emission spectrum. The yellow band (575 nm) corresponds to the hypersensitive transition 4 F 9/2 → 6 H 13/2 (ΔL=2, ΔJ=2), and the blue band (485 nm) corresponds to the 4 F 9/2 → 6 H 15/2 transition. Factors which influence on the yellow- to-blue intensity ratio (Y/B) were investigated. Adjusting to a suitable Y/B, Dy 3+ will emit white light with high colour temperature and can be used for lighting. But Dy 3+ ion has only narrow excitation bands of f-f transitions ranging from 300-500 nm, no broad excitation band such as charge transfer band or f-d transition band exists in the UV region 200-300 nm. Hence its luminescent efficiency is low when it is excited by UV radiation emitted from the mercury plasma. This is one of the drawbacks to its use as lamp phosphor. However, this can be overcome by sensitisation with Gd 3+ , Pb 2+ or other sensitisers such as vanadate shown in this report. Gd 3+ is not only a good matrix, but also a good sensitiser. Using its 8 S 7/2 → 6 D, 6 I and 6 P transitions, the UV excitation energy can be absorbed and transferred to the activator such as Dy 3+ . Therefore, in some cases Gd 3+ is better than Y 3+ which is optical inert as a matrix. For the phosphor Ca 1.96 Pb 0.04 RE 7.9 Dy 0.1 (SiO 4 ) 6 O 2 prepared by sol-gel method, the intensity of Dy 3+ in the Gd 3+ compound (RE=Gd 3+ ) is six times that in the Y 3+ compound. Some new phosphors doped with Dy 3+ and Gd 3+ prepared in our laboratory are reported

Recurrent medulloblastoma: Frequency of tumor enhancement on Gd-DTPA MR imaging

International Nuclear Information System (INIS)

Rollins, N.; Mendelsohn, D.; Mulne, A.; Barton, R.; Diehl, J.; Reyes, N.; Sklar, F.

1990-01-01

Thirty-two children with medulloblastoma were evaluated postoperatively with conventional and gadolinium-enhanced MR imaging. Eleven patients had abnormal cranial MR studies; nine of these had recurrent tumor. In six patients recurrent tumor enhanced with Gd, while in the other three patients recurrent tumor did not enhance. The remaining two patients had areas of abnormal Gd enhancement that were caused by radiation-induced breakdown of the blood-brain barrier rather than by recurrent tumor. This study shows that not all recurrent medulloblastoma enhances and that the absence of Gd enhancement does not necessarily indicate the absence of recurrent tumor

Photoluminescence properties of Gd_2O_3:Eu"3"+ for solid state lighting

International Nuclear Information System (INIS)

Ukare, R.S.; Zade, G.D.; Dhoble, S.J.

2016-01-01

We synthesized Gd_2O_3 doped europium (III) (1 m%) nanophosphors using the precipitation method and combustion method. The synthesized nanophosphors were characterized by X-ray diffraction (XRD) and SEM techniques. The optical properties of the synthesized nanophosphors were investigated by photoluminescence spectroscopy. The XRD patterns of Gd_2O_3 revealed formation of desired cubic phase by both methods. The XRD of nanophosphors synthesized by both methods were highly consistent with standard JCPDS file of Gd_2O_3 indicating no structural change with incorporation of the Eu"3"+ ions in the Gd_2O_3 matrix. Both XRD and SEM result confirms the particle size of prepared sample in nanometer range. The phosphor could be effectively excited by near UV at 395 nm. The Eu"3"+ doping of Gd_2O_3 produced red luminescence around 613 nm. The stimulated CIE chromaticity coordinates were also calculated. (author)

Gd-DOTA enhancement of cerebral and spinal tumors on MR imaging

International Nuclear Information System (INIS)

Berry, I.; Manelfe, C.; Chastin, I.; Arrue, P.; Prere, J.

1987-01-01

The use of Gd-DOTA as a contrast agent in MR imaging to improve the diagnosis of cerebral and spinal tumors was assessed in 20 patients, ten with brain tumors and ten with spinal tumors. Imaging was performed with a 0.5-T Magniscan 5000 unit. T1-weighted (spin-echo and gradient-echo) and T2-weighted (spin-echo) images were acquired before and after intravenous injection of Gd-DOTA, 0.1 mmol/kg. On T1-weighted images, Gd-DOTA enhanced sites of presumed disruption of the blood-brain barrier. This made some brain tumors more conspicuous and helped target biopsies, but did not reveal any additional lesions. On the other hand, the use of Gd-DOTA significantly improved the reliability of spinal tumor imaging compared to imaging performed without contrast agent, allowing delineation of abnormalities on T1-weighted images, which frequently contain fewer artifacts than the most sensitive T2-weighted images. Images obtained with Gd-DOTA could be used by the physician to rule out residual tumor after surgery and to assess recurrences. Additional work should be done to discover whether spinal tumor exploration with MR imaging could include solely T1-weighted sequences, performed before and after contrast agent administration, without T2-weighted sequences

The Interface between Gd and Monolayer MoS2: A First-Principles Study

KAUST Repository

Zhang, Xuejing

2014-12-08

We analyze the electronic structure of interfaces between two-, four- and six-layer Gd(0001) and monolayer MoS2 by first-principles calculations. Strong chemical bonds shift the Fermi energy of MoS2 upwards into the conduction band. At the surface and interface the Gd f states shift to lower energy and new surface/interface Gd d states appear at the Fermi energy, which are strongly hybridized with the Mo 4d states and thus lead to a high spin-polarization (ferromagnetically ordered Mo magnetic moments of 0.15 μB). Gd therefore is an interesting candidate for spin injection into monolayer MoS2.

Demonstration and evaluation of the 20-ton-capacity load-cell-based weighing system, Eldorado Resources, Ltd., Port Hope, Ontario, September 3-4, 1986

International Nuclear Information System (INIS)

Cooley, J.N.; Huxford, T.J.

1986-01-01

On September 3 and 4, 1986, the prototype 20-ton-capacity load-cell-based weighing system (LCBWS) developed by the US Enrichment Safeguards Program (ESP) at Martin Marietta Energy Systems, Inc., was field tested at the Eldorado Resources, Ltd., (ERL) facility in Port Hope, Ontario. The 20-ton-capacity LCBWS has been designed and fabricated for use by the International Atomic Energy Agency (IAEA) for verifying the masses of large-capacity UF 6 cylinders during IAEA safeguards inspections at UF 6 handling facilities. The purpose of the Canadian field test was to demonstrate and to evaluate with IAEA inspectorates and with UF 6 bulk handling facility operators at Eldorado the principles, procedures, and hardware associated with using the 20-ton-capacity LCBWS as a portable means for verifying the masses of 10- and 14-ton UF 6 cylinders. Session participants included representatives from the IAEA, Martin Marietta Energy Systems, Inc., Eldorado Resources, Ltd., the Atomic Energy Control Board (AECB), and the International Safeguards Project Office (ISPO) at Brookhaven National Laboratory (BNL). Appendix A presents the list of participants and their organization affiliation. The two-day field test involved a formal briefing by ESP staff, two cylinder weighing sessions, IAEA critiques of the LCBWS hardware and software, and concluding discussions on the field performance of the system. Appendix B cites the meeting agenda. Summarized in this report are (1) the technical information presented by the system developers, (2) results from the weighing sessions, and (3) observations, suggestions, and concluding statements from meeting participants

Pulsed laser-deposited nanocrystalline GdB{sub 6} thin films on W and Re as field emitters

Energy Technology Data Exchange (ETDEWEB)

Suryawanshi, Sachin R.; More, Mahendra A. [Savitribai Phule Pune University, Department of Physics, Centre for Advanced Studies in Materials Science and Condensed Matter Physics, Pune (India); Singh, Anil K.; Sinha, Sucharita [Bhabha Atomic Research Centre, Laser and Plasma Technology Division, Trombay, Mumbai (India); Phase, Deodatta M. [UGC-DAE Consortium for Scientific Research Indore Centre, Indore (India); Late, Dattatray J. [CSIR-National Chemical Laboratory, Physical and Materials Chemistry Division, Pune (India)

2016-10-15

Gadolinium hexaboride (GdB{sub 6}) nanocrystalline thin films were grown on tungsten (W), rhenium (Re) tips and foil substrates using optimized pulsed laser deposition (PLD) technique. The X-ray diffraction analysis reveals formation of pure, crystalline cubic phase of GdB{sub 6} on W and Re substrates, under the prevailing PLD conditions. The field emission (FE) studies of GdB{sub 6}/W and GdB{sub 6}/Re emitters were performed in a planar diode configuration at the base pressure ∝10{sup -8} mbar. The GdB{sub 6}/W and GdB{sub 6}/Re tip emitters deliver high emission current densities of ∝1.4 and 0.811 mA/cm{sup 2} at an applied field of ∝6.0 and 7.0 V/μm, respectively. The Fowler-Nordheim (F-N) plots were found to be nearly linear showing metallic nature of the emitters. The noticeably high values of field enhancement factor (β) estimated using the slopes of the F-N plots indicate that the PLD GdB{sub 6} coating on W and Re substrates comprises of high-aspect-ratio nanostructures. Interestingly, the GdB{sub 6}/W and GdB{sub 6}/Re planar emitters exhibit excellent current stability at the preset values over a long-term operation, as compared to the tip emitters. Furthermore, the values of workfunction of the GdB{sub 6}/W and GdB6/Re emitters, experimentally measured using ultraviolet photoelectron spectroscopy, are found to be same, ∝1.6 ± 0.1 eV. Despite possessing same workfunction value, the FE characteristics of the GdB{sub 6}/W emitter are markedly different from that of GdB{sub 6}/Re emitter, which can be attributed to the growth of GdB{sub 6} films on W and Re substrates. (orig.)

Ways for accurate analysis of high purity materials using the glow discharge mass spectrometry (GD-MS); Wege zur genauen Charakterisierung hochreiner Materialien mit der Glimmentladungs-Massenspektrometrie (GD-MS)

Energy Technology Data Exchange (ETDEWEB)

Gusarova, Tamara

2010-04-14

The main aim of this work consists in the investigation, development and application of improved possibilities of accurate analysis of high purity materials using the solid sample technique of Glow Discharge Mass Spectrometry (GD-MS), as well as in the sensitivity enhancement of GD Optical Emission Spectrometry (GD-OES) by implicating the hollow cathode effect. The emphasis of the PhD thesis consists in the accurate quantification for GD-MS. As appropriate certified reference materials (CRMs) for calibration are lacking in most cases an accurate quantification especially for trace elements mass fractions at {mu}g kg{sup -1} level can often not be achieved. To overcome this problem and to expand the possibilities of modern GD-MS hereby, synthetic standards were applied for calibration of both high resolution GD-MS instruments ''VG 9000'' and ''Element GD''. The standards were prepared by doping of matrix powder with trace element standard solutions followed by drying and pressing the doped powder to compact pellets. With the quantification approach worked out and described here accurate analysis results with small uncertainties can be achieved for most elements of periodic table in almost every matrix composition. Furthermore direct traceability of the analytical results to the International System of Units (SI) is provided ensuring their higher metrological quality. Numerous additional systematic investigations concerning the preparation of the synthetic standards and their properties were carried out. The results of calibration of GD-MS instruments with synthetic standards for Co (Co-C), Cu, In, Fe and Zn matrices were checked by measuring CRMs. These results were also contrasted with those of other quantification approaches, as usually used in GD-MS routine. The results achieved with synthetic standards had the highest accuracy. The successful participation in the round robin test CCQM-P107 between international

Neutron diffraction studies on GdB6 and TbB6 powders

International Nuclear Information System (INIS)

Luca, S.E.; Amara, M.; Galera, R.M.; Givord, F.; Granovsky, S.; Isnard, O.; Beneu, B.

2004-01-01

We report here the first powder neutron diffraction study of GdB 6 and TbB 6 . GdB 6 and TbB 6 order antiferromagnetically at 15 and 21 K, respectively. In both compounds the transition at T N is of the first order. Moreover GdB 6 presents a second spontaneous magnetic transition at T * =8 K. The present study shows that, in both compounds, the magnetic propagation vectors belong to the star and that the direction of the magnetic moment is perpendicular to the ((1)/(2)) component of the wave-vector in GdB 6 , while in TbB 6 the moment is parallel to it. The deduced low-temperature values of the magnetic moments agree with those of the respective rare-earth trivalent ions

Hypertonic-induced lamin A/C synthesis and distribution to nucleoplasmic speckles is mediated by TonEBP/NFAT5 transcriptional activator

International Nuclear Information System (INIS)

Favale, Nicolas O.; Sterin Speziale, Norma B.; Fernandez Tome, Maria C.

2007-01-01

Lamin A/C is the most studied nucleoskeletal constituent. Lamin A/C expression indicates cell differentiation and is also a structural component of nuclear speckles, which are involved in gene expression regulation. Hypertonicity has been reported to induce renal epithelial cell differentiation and expression of TonEBP (NFAT5), a transcriptional activator of hypertonicity-induced gene transcription. In this paper, we investigate the effect of hypertonicity on lamin A/C expression in MDCK cells and the involvement of TonEBP. Hypertonicity increased lamin A/C expression and its distribution to nucleoplasm with speckled pattern. Microscopy showed codistribution of TonEBP and lamin A/C in nucleoplasmic speckles, and immunoprecipitation demonstrated their interaction. TonEBP silencing caused lamin A/C redistribution from nucleoplasmic speckles to the nuclear rim, followed by lamin decrease, thus showing that hypertonicity induces lamin A/C speckles through a TonEBP-dependent mechanism. We suggest that lamin A/C speckles could serve TonEBP as scaffold thus favoring its role in hypertonicity

Structural and microstructural analysis of the U-Gd-O system using X-Ray diffraction data

International Nuclear Information System (INIS)

Darin, Gaspar; Imakuma, Kengo; Martinez, Luis G.; Turrrilas, Xabier M.; Ichikawa, Rodrigo U.; Silva, André S.B.; Durazzo, Michelangelo; Riella, Humberto G.; Urano, Elita

2017-01-01

Gadolinium is one of the best neutron absorber materials and its usage can be considered as a burnable poison for Light Water Reactors (LWR) and as a sacrificial material in Sodium Fast Reactor (SFR). Most of the experiments in the literature focus on nuclear fuel with up to 12 wt% Gd 2 O 3 . Recently, the phase diagram and melting point has been investigated for high contents of Gd 2 O 3 in the U-Gd-O system, that means a solid solution of the composition (U 1-x , Gd x )O 2 for 0Gd-O system for high contents of Gd 2 O 3 using X-ray diffraction data. Rietveld analysis was applied to obtain cell parameters, atomic positions and atomic displacement factors and compared with literature available. Also, the quantification of phases was performed for the different contents of Gd 2 O 3 in the system. Finally, mean crystallite sizes were determined and correlated with the weight fraction of the phases. (author)

Vacuum ultraviolet excited photoluminescence properties of Gd2O2CO3:Eu3+ phosphor

Institute of Scientific and Technical Information of China (English)

WANG Zhilong; WANG Yuhua; ZHANG Jiachi

2008-01-01

The Gd2O2CO3:Eu3+ with type-II structure phosphor was successfully synthesized via flux method at 400℃ and their photoluminescence properties in vacuum ultraviolet (VUV) region were examined. The broad and strong excitation bands in the range of 153-205 nm owing to the CO32- host absorption and charge transfer (CT) of Gd3+-O2- were observed for Gd2O2CO3:Eu3+. Under 172 nm excitation, Gd2O2CO3:Eu3+ exhibited strong red emission with good color purity, indicating Eu3+ ions located at low symmetry sites and the chromaticity coordination of luminescence for Gd2O2CO3:Eu3+ was (x=0.652, y=0.345). The photoluminescence quenching concentration of Eu3+ excited by 172 nm for Gd2O2CO3:Eu3+ was about 5%. Gd2O2CO3:Eu3+ would be a potential VUV-excited red phosphor applied in mercury-free fluorescent lamps.

The enhancement effects of Gd-DTPA for cerebro-spinal lesions

International Nuclear Information System (INIS)

Mano, Isamu; Yoshida, Hideo; Kono, Takeshi; Tsuchida, Takashi; Terao, Hideo; Iio, Masahiro.

1987-01-01

Effects of Gadolinium DTPA enhancement in MRI for cerebro-spinal lesions were studied on 20 patients. In this study, pre-contrast T 2 weighted image and the postcontrast T 1 weighted image were, especially, compared. Out of 20 cases investigated, the clinical significance of Gd-DTPA was recognized clearly in 14 cases. In the other 6 cases, some new information, though which did not give us the direct clinical significance, was also obtained. It was confirmed that T 2 weighted sequence without Gd-DTPA was the best in sensitivity, while T 1 weighted sequence after Gd-DTPA administration was superior in specificity of the information in making a discrimination between tumor and edema, gliosis and in the time-course of infarction. (author)

Blood brain barrier and brain tissue injury by Gd-DTPA in uremia-induced rabbits

International Nuclear Information System (INIS)

Choi, Sun Seob; Huh, Ki Yeong; Han, Jin Yeong; Lee, Yong Chul; Eun, Choong Gi; Yang, Yeong Il

1996-01-01

An experimental study was carried out to evaluate the morphological changes in the blood brain barrier and neighbouring brain tissue caused by Gd-DTPA in uremia-induced rabbits. Bilateral renal arteries and veins of ten rabbits were ligated. Gd-DTPA(0.2mmol/kg) was intravenously injected into seven rabbits immediately after ligation. After MRI, they were sacrificed 2 or 3 days after ligation in order to observe light and electron microscopic changes in the blood brain barrier and brain tissue. MRI findings were normal, except for enhancement of the superior and inferior sagittal sinuses on T1 weighted images in uremia-induced rabbits injected with Gd-DTPA. On light microscopic examination, these rabbits showed perivascular edema and glial fibrillary acidic protein expression: electron microscopic examination showed separation of tight junctions of endothelial cells, duplication/rarefaction of basal lamina, increased lysosomes of neurons with neuronal death, demyelination of myelin, and extravasation of red blood cells. Uremia-induced rabbits injected with Gd-DTPA showed more severe changes than those without Gd-DTPA injection. Injuries to the blood brain barrier and neighbouring brain tissue were aggravated by Gd-DTPA administration in uremia-induced rabbits. These findings appear to be associated with the neurotoxicity of Gd-DTPA

Exogenous and Endogeneous Disialosyl Ganglioside GD1b Induces Apoptosis of MCF-7 Human Breast Cancer Cells

Directory of Open Access Journals (Sweden)

Sun-Hyung Ha

2016-04-01

Full Text Available Gangliosides have been known to play a role in the regulation of apoptosis in cancer cells. This study has employed disialyl-ganglioside GD1b to apoptosis in human breast cancer MCF-7 cells using exogenous treatment of the cells with GD1b and endogenous expression of GD1b in MCF-7 cells. First, apoptosis in MCF-7 cells was observed after treatment of GD1b. Treatment of MCF-7 cells with GD1b reduced cell growth rates in a dose and time dependent manner during GD1b treatment, as determined by XTT assay. Among the various gangliosides, GD1b specifically induced apoptosis of the MCF-7 cells. Flow cytometry and immunofluorescence assays showed that GD1b specifically induces apoptosis in the MCF-7 cells with Annexin V binding for apoptotic actions in early stage and propidium iodide (PI staining the nucleus of the MCF-7 cells. Treatment of MCF-7 cells with GD1b activated apoptotic molecules such as processed forms of caspase-8, -7 and PARP (Poly(ADP-ribose polymerase, without any change in the expression of mitochondria-mediated apoptosis molecules such as Bax and Bcl-2. Second, to investigate the effect of endogenously produced GD1b on the regulation of cell function, UDP-gal: β1,3-galactosyltransferase-2 (GD1b synthase, Gal-T2 gene has been transfected into the MCF-7 cells. Using the GD1b synthase-transfectants, apoptosis-related signal proteins linked to phenotype changes were examined. Similar to the exogenous GD1b treatment, the cell growth of the GD1b synthase gene-transfectants was significantly suppressed compared with the vector-transfectant cell lines and transfection activated the apoptotic molecules such as processed forms of caspase-8, -7 and PARP, but not the levels of expression of Bax and Bcl-2. GD1b-induced apoptosis was blocked by caspase inhibitor, Z-VAD. Therefore, taken together, it was concluded that GD1b could play an important role in the regulation of breast cancer apoptosis.

MR study of acute myocardial infarction with injection of Gd-DOTA (Fifteen patients)

International Nuclear Information System (INIS)

Richoz, B.; Delcour, C.; Depelchin, P.; Lenaers, A.; Jacquemin, C.; Gusella, P.; Struyven, J.; Richoz, B.

1990-01-01

We studied 15 patients 4 to 8 days after myocardial infarction by using ECG gated MR before and after administration of 0.2 mmol/kg Gd-DOTA. The diagnosis in each patient was confirmed by electrocardiographic criteria, elevated levels of fractionated creatine kinase (CK) isoenzyme, thallium scintigraphy, ventriculography and coronarography. T1-weighted, spin-echo images, were obtained before and immediately after injection of Gd-DOTA and were repeated 15 min later. The site of infarction was visualized in 10 patients as an area of high signal intensity after the injection of Gd-DOTA. Contrast between normal and infarcted myocardium was greatest 15 min after injection. Three patients were excluded because of failure to acquire adequate MR studies. In 2 other patients, the infarct were not detected. Before injection of Gd-DOTA, only 2 infarcts were detected. These results suggest that Gd-DOTA can improve MR visualization and detection of acute myocardial infarction [fr

Experiment and density functional theory analyses of GdTaO4 single crystal

Science.gov (United States)

Ding, Shoujun; Kinross, Ashlie; Wang, Xiaofei; Yang, Huajun; Zhang, Qingli; Liu, Wenpeng; Sun, Dunlu

2018-05-01

GdTaO4 is a type of excellent materials that can be used as scintillation, laser matrix as well as self-activated phosphor has generated significant interest. Whereas its band structure, electronic structure and optical properties are still need elucidation. To solve this intriguing problem, high-quality GdTaO4 single crystal (M-type) was grown successfully using Czochralski method. Its structure as well as optical properties was determined in experiment. Moreover, a systematic theoretical calculation based on the density function theory methods were performed on M-type and M‧-type GdTaO4 and their band structure, density of state as well as optical properties were obtained. Combine with the performed experiment results, the calculated results were proved with high reliability. Hence, the calculated results obtained in this work could provide a deep understanding of GdTaO4 material, which also useful for the further investigation on GdTaO4 material.

Gd{sub 2}O{sub 3} nanoparticles stabilized by hydrothermally modified dextrose for positive contrast magnetic resonance imaging

Energy Technology Data Exchange (ETDEWEB)

Babić-Stojić, Branka, E-mail: babic@vinca.rs [Vinča Institute of Nuclear Sciences, University of Belgrade, PO Box 522, 11001 Belgrade (Serbia); Jokanović, Vukoman; Milivojević, Dušan [Vinča Institute of Nuclear Sciences, University of Belgrade, PO Box 522, 11001 Belgrade (Serbia); Požek, Miroslav [Department of Physics, Faculty of Science, University of Zagreb, 10000 Zagreb (Croatia); Jagličić, Zvonko [Institute of Mathematics, Physics and Mechanics, Jadranska 19, 1000 Ljubljana (Slovenia); Makovec, Darko [Department for Materials Synthesis, Jožef Stefan Institute, Jamova 39, 1000 Ljubljana (Slovenia); Arsikin, Katarina; Paunović, Verica [Institute of Microbiology and Immunology, School of Medicine, University of Belgrade, 11000 Belgrade (Serbia)

2016-04-01

Gd{sub 2}O{sub 3} nanoparticles of a few nm in size and their agglomerates dispersed in dextrose derived polymer template were synthesized by hydrothermal treatment. The produced nanosized material was investigated by TEM, FTIR spectroscopy, SQUID measurements and NMR relaxometry. Biological evaluation of this material was done by crystal violet and MTT assays to determine the cell viability. Longitudinal and transverse NMR relaxivities of water diluted Gd{sub 2}O{sub 3} nanoparticle dispersions measured at the magnetic field of 1.5 T, estimated to be r{sub 1}(Gd{sub 2}O{sub 3})=9.6 s{sup −1} mM{sup −1} in the Gd concentration range 0.1–30 mM and r{sub 2}(Gd{sub 2}O{sub 3})=17.7 s{sup −1} mM{sup −1} in the lower concentration range 0.1–0.8 mM, are significantly higher than the corresponding relaxivities measured for the standard contrast agent r{sub 1}(Gd-DTPA)=4.1 s{sup −1} mM{sup −1} and r{sub 2}(Gd-DTPA)=5.1 s{sup −1} mM{sup −1}. The ratio of the two relaxivities for Gd{sub 2}O{sub 3} nanoparticles r{sub 2}/r{sub 1}=1.8 is suitable for T{sub 1}-weighted imaging. Good MRI signal intensities of the water diluted Gd{sub 2}O{sub 3} nanoparticle dispersions were recorded at lower Gd concentrations 0.2–0.8 mM. The Gd{sub 2}O{sub 3} samples did not exert any significant cytotoxic effects at Gd concentrations of 0.2 mM and below. These properties of the produced Gd{sub 2}O{sub 3} nanoparticles in hydrothermally modified dextrose make them promising for potential application in MRI for the design of a positive MRI contrast agent. - Highlights: • Gd{sub 2}O{sub 3} nanoparticles (NPs) were stabilized by hydrothermally modified dextrose. • Magnetic moment per Gd{sup 3+} ion in the Gd{sub 2}O{sub 3} NPs is much lower than that in the bulk. • The ratio r{sub 2}/r{sub 1}=1.8 for Gd{sub 2}O{sub 3} NPs dispersions is favorable for T{sub 1}-weighted MRI. • Gd{sub 2}O{sub 3} NPs dispersions had good MRI signal intensity just at lower Gd concentrations

Electromagnetic Properties of (Gd, Y)Ba2Cu3Ox Superconducting Tapes With High Levels of Zr Addition

Energy Technology Data Exchange (ETDEWEB)

Liu, Y; Yao, Y; Chen, Y; Khatri, ND; Liu, J; Galtsyan, E; Lei, C; Selvamanickam, V

2013-06-01

The dependence of the critical current density (J(c)) on the orientation of applied magnetic fields was studied in Zr-doped (Gd, Y)Ba2Cu3Ox tapes fabricated by metal organic chemical vapor deposition. The in-field performance of J(c) of (Gd, Y)Ba2Cu3Ox tapes with Zr-doping levels of 7.5-30 at.% was investigated up to 5 T over a temperature range of 40-77 K. The highest critical currents (I-c) at H parallel to c and the highest values of minimum Ic in angular dependence measurements were achieved in the tapes with 20% Zr doping over a broad range of temperature and magnetic field conditions measured. The electromagnetic properties have been related to the changes in BaZrO3 content and microstructure.

Twitching motility and biofilm formation are associated with tonB1 in Xylella fastidiosa

OpenAIRE

Cursino, Luciana; Li, Yaxin; Zaini, Paulo A.; De La Fuente, Leonardo; Hoch, Harvey C.; Burr, Thomas J.

2017-01-01

A mutation in the Xylella fastidiosa tonB1 gene resulted in loss of twitching motility and in significantly less biofilm formation as compared with a wild type. The altered motility and biofilm phenotypes were restored by complementation with a functional copy of the gene. The mutation affected virulence as measured by Pierce's disease symptoms on grapevines. The role of TonB1 in twitching and biofilm formation appears to be independent of the characteristic iron-uptake function of this prote...

Gd doping induced weak ferromagnetic ordering in ZnS nanoparticles synthesized by low temperature co-precipitation technique

Energy Technology Data Exchange (ETDEWEB)

Kaur, Palvinder [Department of Physics, Punjabi University, Patiala, Punjab, 147002 (India); Kumar, Sanjeev, E-mail: sanjeev04101977@gmail.com [Applied Science Department, PEC University of Technology, Chandigarh, 160012 (India); Chen, Chi-Liang, E-mail: chen.cl@nsrrc.org.tw [National Synchrotron Radiation Research Center (NSRRC), Hsinchu, 30076, Taiwan (China); Yang, Kai-Siang [National Synchrotron Radiation Research Center (NSRRC), Hsinchu, 30076, Taiwan (China); Department of Mechanical Engineering, National Taipei University of Technology, Taipei, Taiwan (China); Wei, Da-Hua [Department of Mechanical Engineering, National Taipei University of Technology, Taipei, Taiwan (China); Dong, Chung-Li [Department of Physics, Tamkang University, Tamsui, Taiwan (China); Srivastava, C. [Materials Engineering Department, Indian Institute of Science, Bangalore, 560012 (India); Rao, S.M. [Department of Physics, Punjabi University, Patiala, Punjab, 147002 (India); Institute of Physics, Academia Sinica, Taipei, 11529, Taiwan (China)

2017-01-15

Zn{sub 1−x}Gd{sub x}S nanoparticles with Gd concentration x = 0.00, 0.02 and 0.04 were synthesized by the chemical co-precipitation technique using thioglycerol as capping agent. X-ray diffraction (XRD), transmission electron microscopy (TEM), photoluminescence (PL) spectroscopy, X-ray absorption near-edge structure (XANES) and vibrating sample magnetometer (VSM) were employed to characterize the as synthesized Gd doped ZnS nanoparticles. XRD and TEM studies show the formation of cubic ZnS nanoparticles with an average size in the range 5–10 nm. The doping did not alter the phase of the ZnS. The PL spectra of doped ZnS nanoparticles showed the presence of sulphur vacancies in the lattice. XANES of Gd doped ZnS nanoparticles depicts spectral changes may arise from charge transfer between host Zn and dopant Gd ions. A VSM study shows that the weak ferromagnetic behaviour increases with increase in Gd doping ZnS nanoparticles. - Highlights: • Gd doped ZnS nanoparticles synthesized using co-precipitation technique. • PL studies depict sulphur and zinc vacancies in Gd doped ZnS nanoparticles. • XANES studies depict the charge transfer between host Zn and dopant Gd ions. • Room temperature weak ferromagnetism is observed in Gd doped ZnS nanoparticles.

Gd doping induced weak ferromagnetic ordering in ZnS nanoparticles synthesized by low temperature co-precipitation technique

International Nuclear Information System (INIS)

Kaur, Palvinder; Kumar, Sanjeev; Chen, Chi-Liang; Yang, Kai-Siang; Wei, Da-Hua; Dong, Chung-Li; Srivastava, C.; Rao, S.M.

2017-01-01

Zn_1_−_xGd_xS nanoparticles with Gd concentration x = 0.00, 0.02 and 0.04 were synthesized by the chemical co-precipitation technique using thioglycerol as capping agent. X-ray diffraction (XRD), transmission electron microscopy (TEM), photoluminescence (PL) spectroscopy, X-ray absorption near-edge structure (XANES) and vibrating sample magnetometer (VSM) were employed to characterize the as synthesized Gd doped ZnS nanoparticles. XRD and TEM studies show the formation of cubic ZnS nanoparticles with an average size in the range 5–10 nm. The doping did not alter the phase of the ZnS. The PL spectra of doped ZnS nanoparticles showed the presence of sulphur vacancies in the lattice. XANES of Gd doped ZnS nanoparticles depicts spectral changes may arise from charge transfer between host Zn and dopant Gd ions. A VSM study shows that the weak ferromagnetic behaviour increases with increase in Gd doping ZnS nanoparticles. - Highlights: • Gd doped ZnS nanoparticles synthesized using co-precipitation technique. • PL studies depict sulphur and zinc vacancies in Gd doped ZnS nanoparticles. • XANES studies depict the charge transfer between host Zn and dopant Gd ions. • Room temperature weak ferromagnetism is observed in Gd doped ZnS nanoparticles.

Synthesis and Characterization of Gd and Nd Nanoparticles

Science.gov (United States)

Romero, Dulce G.; Ho, Pei-Chun; Attar, Saeed

2009-03-01

Due to the reduced dimensionality, nano-sized materials have physical properties significantly different from the bulk material, such as, superparamagnetic behavior, enhanced magnetization, and self-organization [1-3]. Nano-sized materials have great potential for technical applications, for example, magnetic information storage, imaging, medical devices, and magnetic refrigeration. In this report, we will present the growth and filtration of rare-earth Gd and Nd nanoparticles by the inverse micelle technique [4]. The results of the characterization of these clusters by X- ray diffraction, scanning electron microscope, and energy-dispersive x-ray spectroscopy will be presented. [1] D.C. Douglass, et al. Phys. Rev. B. 47, 19 (1993). [2] J.P. Chen, et al. Phys. Rev. B. 51, 11527 (1995). [3] C. Petit, et al. Advanced Materials. 10, 259 (1998). [4] X.M. Lin, et al. Langmuir. 14, 7140 (1998).

Influence of hydrogenation and mechanical grinding on the structural and ferromagnetic properties of GdFeSi

Energy Technology Data Exchange (ETDEWEB)

Chevalier, Bernard; Duttine, Mathieu; Wattiaux, Alain [Universite de Bordeaux, CNRS ICMCB, Pessac (France)

2016-08-01

Hydrogen insertion into GdFeSi induces (i) a structural transition from a tetragonal CeFeSi-type to a tetragonal ZrCuSiAs-type, (ii) an anisotropic expansion of the unit cell parameters because the a parameter decreases, whereas the c parameter increases, and (iii) a decrease in Curie temperature from 121 to 20 K. On the contrary, an amorphous ferromagnet (T{sub C} = 65 K) is obtained by mechanical grinding of GdFeSi. The three compounds (GdFeSi, GdFeSiH, and amorphous GdFeSi) were investigated by {sup 57}Fe Moessbauer spectroscopy. At 4.2 K, this study has revealed that the magnetically ordered Gd substructure produces a small transferred hyperfine magnetic field at the {sup 57}Fe nucleus.

Conversion of green emission into white light in Gd{sub 2}O{sub 3} nanophosphors

Energy Technology Data Exchange (ETDEWEB)

Jayasimhadri, M.; Ratnam, B.V. [Department of Physics, Changwon National University, Changwon, 641-773 (Korea, Republic of); Jang, Kiwan, E-mail: kwjang@changwon.ac.k [Department of Physics, Changwon National University, Changwon, 641-773 (Korea, Republic of); Lee, Ho Sueb [Department of Physics, Changwon National University, Changwon, 641-773 (Korea, Republic of); Yi, Soung-Soo [Department of Photonics, Silla University, Busan (Korea, Republic of); Jeong, Jung-Hyun [Department of Physics, Pukyong National University, Busan (Korea, Republic of)

2010-09-01

Gd{sub 2}O{sub 3} nanophosphors were prepared by combustion synthesis with and without doping of Dy{sup 3+} ions. The X-ray powder diffraction patterns indicate that as-prepared Gd{sub 2}O{sub 3} and 0.1 mol% Dy{sub 2}O{sub 3} doped Gd{sub 2}O{sub 3} nanophosphors have monoclinic structures. The transmission electron microscope (TEM) studies revealed that the as-prepared phosphors had an average crystallite sizes around 37 nm. The excitation and emission properties have been investigated for Dy{sup 3+} doped and undoped Gd{sub 2}O{sub 3} nanophosphors. New emission bands were observed in the visible region for Gd{sub 2}O{sub 3} nanophosphors without any rare earth ion doping under different excitations. A tentative mechanism for the origin of luminescence from Gd{sub 2}O{sub 3} host was discussed. Emission properties also measured for 0.1 mol% Dy{sup 3+} doped Gd{sub 2}O{sub 3} nanophosphors and found the characteristic Dy{sup 3+} visible emissions at 489 and 580 nm due to {sup 4}F{sub 9/2} {yields} {sup 6}H{sub 15/2} and {sup 4}F{sub 9/2} {yields} {sup 6}H{sub 13/2} transitions, respectively. The chromaticity coordinates were calculated based on the emission spectra of Dy{sup 3+} doped and undoped Gd{sub 2}O{sub 3} nanophosphors and analyzed with Commission Internationale de l'Eclairage (CIE) chromaticity diagram. These nanophosphors exhibit green color in undoped Gd{sub 2}O{sub 3} and white color after adding 0.1 mol% Dy{sub 2}O{sub 3} to Gd{sub 2}O{sub 3} nanophosphors under UV excitation. These phosphors could be a promising phosphor for applications in flat panel displays.

Ab initio investigation on the magnetic ordering in Gd doped ZnO

KAUST Repository

Bantounas, Ioannis; Goumri-Said, Souraya; Benali Kanoun, Mohammed; Manchon, Aurelien; Roqan, Iman S.; Schwingenschlö gl, Udo

2011-01-01

The current study investigates the magnetic properties of the Gdx Zn1−xO, with x=0.0625 and 0.0185, dopedsemiconductor using the full potential (linearized) augmented plane wave plus local orbital method. We show that in contrast to the findings of Shi et al. [J. Appl. Phys. 106, 023910 (2009)], the implementation of the Hubbard U parameter to the Gd f states favors an antiferromagnetic phase in both wurtzite GdO and Gdx Zn1−xO. Spin polarized calculations on Gdx Zn1−xO indicate that, even if a ferromagnetic ground state were favored, the magnetic influence of Gd in a perfect ZnO wurtzite lattice is highly localized and limited to the first three nearest neighboring O atoms. Increasing the supercell size and thus diluting the concentration of Gd within the ZnO matrix does not show any changes in the net magnetic moment between these three O atoms nor in the remaining lattice sites, indicating that sizing effects do not influence the range of matrix polarization. We conclude that the localized Gd induced polarization can not account for long range magnetic ordering in a defect-free ZnO wurtzite lattice.

Ab initio investigation on the magnetic ordering in Gd doped ZnO

KAUST Repository

Bantounas, Ioannis

2011-04-22

The current study investigates the magnetic properties of the Gdx Zn1−xO, with x=0.0625 and 0.0185, dopedsemiconductor using the full potential (linearized) augmented plane wave plus local orbital method. We show that in contrast to the findings of Shi et al. [J. Appl. Phys. 106, 023910 (2009)], the implementation of the Hubbard U parameter to the Gd f states favors an antiferromagnetic phase in both wurtzite GdO and Gdx Zn1−xO. Spin polarized calculations on Gdx Zn1−xO indicate that, even if a ferromagnetic ground state were favored, the magnetic influence of Gd in a perfect ZnO wurtzite lattice is highly localized and limited to the first three nearest neighboring O atoms. Increasing the supercell size and thus diluting the concentration of Gd within the ZnO matrix does not show any changes in the net magnetic moment between these three O atoms nor in the remaining lattice sites, indicating that sizing effects do not influence the range of matrix polarization. We conclude that the localized Gd induced polarization can not account for long range magnetic ordering in a defect-free ZnO wurtzite lattice.

Clinical utility of Gd-DTPA subtraction MR imaging for spinal bone metastasis

International Nuclear Information System (INIS)

Ando, Keiichi; Murakami, Masao; Kuroda, Yasumasa

1993-01-01

Based on reports that Gd-DTPA contributes to the detection of tumors, we used it in 31 cases (97 lesions) of spinal bone metastases. The result was that Gd-DTPA increased the intensity of tumors and the surrounding bone marrow to almost the same level in 53%. To show the metastases clearly, an existing subtraction command system was utilized. The technique included the pixel-by-pixel method, to obtain a Gd-DTPA T1-weighted image (T1WI) subtracted by the original T1WI. The detectability of the subtraction image was improved up to 96%, but was less than the original T1WI (99%). Because of the different imaging rationale between two methods, a means to assess the quality of diagnosis must be proposed. To check the normal background, the same kind of postprocessing was performed in 21 patients without malignancy. Gd-DTPA prefusion was highest in the paravertebral veins, moderate in muscles and epidural fat, and lowest in the spinal cord, intervertebral disk and bone cortex. Gd-DTPA enhanced subtraction MR imaging provides a new diagnostic tool to detect and to assess bone metastasis. (author)

Contribution to the qualification of Gd calculation in PWR reactors

International Nuclear Information System (INIS)

Chaucheprat, Patrick.

1982-06-01

This thesis presents the state of knowledge on gadolinium and the advantages of its use as burnable poison. A study on the behaviour of gadolinium makes it possible to bring out the essential parameters to which it is sensitive. The most important part of this work is devoted to the measurements by oscillations carried out in Minerve in 1981. The conceiving and implementation of this campaign are reported. The experimental results and the amending factors linked to the interpretation are presented. To complete this study at zero time, it seemed useful to process configurations with fuel clusters of UO 2 - Gd 2 O 3 in order to see the effect of UO 2 - Gd 2 O 3 rods in interaction. To this end, efficiency determinations of UO 2 - Gd 2 O 3 rod clusters were carried out in the Melodie lattice. The second part of this work involves the change in the gadolinium. Two main points are tackled here. The first concerns the determinations by oscillations of ''reconstituted'' samples that are composed of two concentric rings with various 235 U enrichments and gadolinium levels so as to simulate irradiated UO 2 - Gd 2 O 3 fuel. The second point is devoted to the description of the GEDEON experiment. UO 2 - Gd 2 O 3 rods will be irradiated in a 13 x 13 lattice of which the spectrum is representative of that of a PWR. This experiment will take place in the centre of the Melusine reactor at Grenoble [fr

Magnetic properties of GdMnO3 nanoparticles embedded in mesoporous silica

Science.gov (United States)

Tajiri, Takayuki; Mito, Masaki; Deguchi, Hiroyuki; Kohno, Atsushi

2018-05-01

Perovskite manganite GdMnO3 nanoparticles were synthesized using mesoporous silica as a template, and their magnetic properties and crystal structure were investigated. Powder X-ray diffraction data indicated successful synthesis of the GdMnO3 nanoparticles, with mean particle sizes of 13.9 and 20.9 nm. The lattice constants for the nanoparticles were slightly different from those for the bulk material and varied with the particle size. The magnetic transition temperatures for the nanoparticles were higher than those of the bulk crystal. The synthesized GdMnO3 nanoparticles exhibited superparamagnetic behaviors: The blocking temperature, coercive field, and transition temperature depended on the particle size. Magnetic measurements and crystal structure analysis suggest that the changes in the magnetic properties for GdMnO3 nanoparticles can be attributed to the modulation of the crystallographic structure.

Anti-Neuroblastoma Activity of Gold Nanorods Bound with GD2 Monoclonal Antibody under Near-Infrared Laser Irradiation

International Nuclear Information System (INIS)

Peng, Ching-An; Wang, Chung-Hao

2011-01-01

High-risk neuroblastoma is one of the most common deaths in pediatric oncology. Current treatment of this disease involves a coordinated sequence of chemotherapy, surgery, and radiation. Further advances in therapy will require the targeting of tumor cells in a more selective and efficient way so that survival can be improved without substantially increasing toxicity. To achieve tumor-selective delivery, disialoganglioside (GD2) expressed by almost all neuroblastoma tumors represents a potential molecular target that can be exploited for tumor-selective delivery. In this study, GD2 monoclonal antibody (anti-GD2) was conjugated to gold nanorods (GNRs) which are one of anisotropic nanomaterials that can absorb near-infrared (NIR) laser light and convert it to energy for photothermolysis of tumor cells. Thiolated chitosan, due to its biocompatibility, was used to replace cetyltrimethylammonium bromide (CTAB) originally used in the synthesis of gold nanorods. In order to specifically target GD2 overexpressed on the surface of neuroblastoma stNB-V1 cells, anti-GD2 was conjugated to chitosan modified GNRs (CGNRs). To examine the fate of CGNRs conjugated with anti-GD2 after incubation with neuroblastoma cells, rhadoamine B was labeled on CGNRs functionalized with anti-GD2. Our results illustrated that anti-GD2-conjugated CGNRs were extensively endocytosed by GD2 + stNB-V1 neuroblastoma cells via antibody-mediated endocytosis. In addition, we showed that anti-GD2 bound CGNRs were not internalized by GD2 − SH-SY5Y neuroblastoma cells. After anti-GD2-linked CGNRs were incubated with neuroblatoma cells for six hours, the treated cells were further irradiated with 808 nm NIR laser. Post-NIR laser exposure, when examined by calcein-AM dye, stNB-V1 cells all underwent necrosis, while non-GD2 expressing SH-SY5Y cells all remained viable. Based on the in vitro study, CGNRs bound with anti-GD2 has the potential to be utilized as a therapeutic thermal coupling agent that generates

Gd-substituted Bi-2223 superconductor

Indian Academy of Sciences (India)

The effects of gadolinium doping at calcium site on the normal and super- conducting properties of Bi-2223 system were ... quantities of the metal oxides and the carbonates were taken and thoroughly mixed. The calcination of the mixture after .... Therefore, Gd has higher solubility in (BiPb)-2223 as compared to Pr, and is, ...

Interplay of spin-dependent delocalization and magnetic anisotropy in the ground and excited states of [Gd2@C78]- and [Gd2@C80]-

Science.gov (United States)

Mansikkamäki, Akseli; Popov, Alexey A.; Deng, Qingming; Iwahara, Naoya; Chibotaru, Liviu F.

2017-09-01

The magnetic properties and electronic structure of the ground and excited states of two recently characterized endohedral metallo-fullerenes, [Gd2@C78]- (1) and [Gd2@C80]- (2), have been studied by theoretical methods. The systems can be considered as [Gd2]5+ dimers encapsulated in a fullerene cage with the fifteen unpaired electrons ferromagnetically coupled into an S = 15/2 high-spin configuration in the ground state. The microscopic mechanisms governing the Gd-Gd interactions leading to the ferromagnetic ground state are examined by a combination of density functional and ab initio calculations and the full energy spectrum of the ground and lowest excited states is constructed by means of ab initio model Hamiltonians. The ground state is characterized by strong electron delocalization bordering on a σ type one-electron covalent bond and minor zero-field splitting (ZFS) that is successfully described as a second order spin-orbit coupling effect. We have shown that the observed ferromagnetic interaction originates from Hund's rule coupling and not from the conventional double exchange mechanism. The calculated ZFS parameters of 1 and 2 in their optimized geometries are in qualitative agreement with experimental EPR results. The higher excited states display less electron delocalization, but at the same time they possess unquenched first-order angular momentum. This leads to strong spin-orbit coupling and highly anisotropic energy spectrum. The analysis of the excited states presented here constitutes the first detailed study of the effects of spin-dependent delocalization in the presence of first order orbital angular momentum and the obtained results can be applied to other mixed valence lanthanide systems.

The manufacture process and properties of (U, Gd)O2 burnable poisonous fuel pellets

International Nuclear Information System (INIS)

Yi Wei; Tang Yueming; Dai Shengping; Yang Youqing; Zuo Guoping; Wu Shihong; Gu Xiaofei; Gu Mingfei

2006-03-01

The main properties of important raw powder materials used in the (U, Gd)O 2 burnable poisonous fuel pellets production line of NPIC are presented. The powders included UO 2 , Gd 2 O 3 , (U, Gd) 3 O 8 and necessary additives, such as ammonium oxalate and zinc stearate. And the main properties of (U, Gd)O 2 burnable poisonous fuel pellets and the manufacture processes, such as ball-milling blending, granulation, pressing, sintering and grinding are also described. Moreover, the main effect of the process parameters controlled in the manufacture process have been discussed. (authors)

Hot corrosion behavior of YSZ, Gd2Zr2O7 and YSZ/Gd2Zr2O7 thermal barrier coatings exposed to molten sulfate and vanadate salt

Science.gov (United States)

Ozgurluk, Yasin; Doleker, Kadir Mert; Karaoglanli, Abdullah Cahit

2018-04-01

Thermal barrier coatings (TBCs) are mostly used in critical components of aircraft gas turbine engines. Hot corrosion is among the main deteriorating factors in TBCs which results from the effect of molten salt on the coating-gas interface. This type of corrosion is observed as a result of contamination accumulated during combustion processes. Fuels used in aviation industry generally contain impurities such as vanadium oxide (V2O5) and sodium sulfate (Na2SO4). These impurities damage turbines' inlet at elevated temperatures because of chemical reaction. Yttria stabilized zirconia (YSZ) is a conventional top coating material for TBCs while Gd2Zr2O7 is a new promising top coating material for TBCs. In this study, CoNiCrAlY metallic bond coat was deposited on Inconel 718 nickel based superalloy substrate material with a thickness about 100 μm using cold gas dynamic spray (CGDS) method. Production of TBCs were done with deposition of YSZ, Gd2Zr2O7, YSZ/Gd2Zr2O7 ceramic top coating materials using EB-PVD method, having a total thickness of 300 μm. Hot corrosion behavior of YSZ, Gd2Zr2O7, YSZ/Gd2Zr2O7 TBC systems were exposed to 45 wt.% Na2SO4 and 55 wt.% V2O5 molten salt mixtures at 1000 °C temperature. TBC samples were investigated and compared using scanning electron microscope (SEM), energy dispersive spectroscopy (EDS) analysis and X-ray diffractometer (XRD). The hot corrosion failure mechanisms of YSZ, Gd2Zr2O7 and YSZ/Gd2Zr2O7 TBCs in the molten salts were evaluated.

Combustion characteristics and NO formation for biomass blends in a 35-ton-per-hour travelling grate utility boiler.

Science.gov (United States)

Li, Zhengqi; Zhao, Wei; Li, Ruiyang; Wang, Zhenwang; Li, Yuan; Zhao, Guangbo

2009-04-01

Measurements were taken for a 35-ton-per-hour biomass-fired travelling grate boiler. Local mean concentrations of O(2), CO, SO(2) and NO gas species and gas temperatures were determined in the region above the grate. For a 28-ton-per-hour load, the mass ratios of biomass fly ash and boiler slag were 42% and 58%, the boiler efficiency was 81.56%, and the concentrations of NO(x) and SO(2) at 6% O(2) were 257 and 84 mg/m(3). For an 18-ton-per-hour load, the fuel burning zone was nearer to the inlet than it was for the 28-ton-per-hour load, and the contents of CO and NO in the fuel burning zone above the grate were lower.

Structural and microstructural analysis of the U-Gd-O system using X-Ray diffraction data

Energy Technology Data Exchange (ETDEWEB)

Darin, Gaspar; Imakuma, Kengo; Martinez, Luis G.; Turrrilas, Xabier M.; Ichikawa, Rodrigo U.; Silva, André S.B.; Durazzo, Michelangelo; Riella, Humberto G.; Urano, Elita, E-mail: gaspardarin@gmail.com, E-mail: kimakuma@ipen.br, E-mail: lgallego@ipen.br, E-mail: ichikawa@usp.br, E-mail: andre.santos.silva@ipen.br, E-mail: mdurazzo@ipen.br, E-mail: riella@enq.ufsc.br, E-mail: elitaucf@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Centro de Combustíveis Nuclear; Institute of Material Science of Barcelona (ICMAB) Barcelona (Spain)

2017-11-01

Gadolinium is one of the best neutron absorber materials and its usage can be considered as a burnable poison for Light Water Reactors (LWR) and as a sacrificial material in Sodium Fast Reactor (SFR). Most of the experiments in the literature focus on nuclear fuel with up to 12 wt% Gd{sub 2}O{sub 3}. Recently, the phase diagram and melting point has been investigated for high contents of Gd{sub 2}O{sub 3} in the U-Gd-O system, that means a solid solution of the composition (U{sub 1-x}, Gd{sub x})O{sub 2} for 0Gd-O system for high contents of Gd{sub 2}O{sub 3} using X-ray diffraction data. Rietveld analysis was applied to obtain cell parameters, atomic positions and atomic displacement factors and compared with literature available. Also, the quantification of phases was performed for the different contents of Gd{sub 2}O{sub 3} in the system. Finally, mean crystallite sizes were determined and correlated with the weight fraction of the phases. (author)

Manganese and Gd-DTPA stearyl liposomes as reticuloendothelial-system-specific MR imaging contrast agents

International Nuclear Information System (INIS)

Wuthrich, R.; Schwendener, R.; Duewell, S.; VonSchulthess, G.K.; Fuchs, W.A.

1988-01-01

Liposomes can be used to target metal ions as MR contrast agents to liver and spleen. It was the aim of this work to examine unilamellar liposomes containing manganese and gadolinium ions with respect to their targetting ability, contrast enhancement, and in vivo kinetics in rats and dogs. Unilamellar liposomes containing DTPA stearate were complexed with Mn/sup 2+/ and Gd/sup 3+/ resulting in vesicles of 30-40 nm. Injected into rats, approximately 35% of manganese liposomes were present in the liver after 30-60 minutes, and after 24 hours more than 80% had been eliminated. The pharmacokinetics of gadolinium were more protracted. In MR imaging, a reduction in the T1 of the liver parenchyma from 450 to 170 and 280 msec was observed for manganese and gadolinium liposomes (0.03 mmol/kg body weight), respectively, with the liver appearing as bright as fat. Manganese (and Gd-DTPA) stearyl liposomes are potential organ-selective contrast agents for liver and spleen and are eliminated through a hepatobiliary route

Thermal, defects, mechanical and spectral properties of Nd-doped GdNbO{sub 4} laser crystal

Energy Technology Data Exchange (ETDEWEB)

Ding, Shoujun [Chinese Academy of Sciences, Anhui Institute of Optics and Fine Mechanics, Hefei, Anhui Province (China); University of Science and Technology of China, Hefei (China); Zhang, Qingli; Luo, Jianqiao; Liu, Wenpeng; Wang, Xiaofei; Sun, Guihua; Li, Xiuli; Sun, Dunlu [Chinese Academy of Sciences, Anhui Institute of Optics and Fine Mechanics, Hefei, Anhui Province (China)

2017-05-15

A Nd-doped GdNbO{sub 4} crystal was grown successfully by Czochralski method. Its monoclinic structure was determined by X-ray diffraction; the unit-cell parameters are a = 5.38 Aa, b = 11.09 Aa, c = 5.11 Aa, and β = 94.56 . The morphological defects of Nd:GdNbO{sub 4} crystal were investigated using the chemical etching with the phosphoric acid etchant. For a new crystal, the physical properties are of great importance. The hardness and density of Nd:GdNbO{sub 4} were investigated first. Thermal properties of Nd:GdNbO{sub 4}, including thermal expansion coefficient and specific heat, were measured along a-, b-, and c-crystalline axes. Thermal properties indicate that the Nd:GdNbO{sub 4} pumped along c-axis can reduce the thermal lensing effect effectively. The specific heat is 0.53 J g{sup -1} K{sup -1} at 300 K, indicating a relatively high damage threshold of Nd:GdNbO{sub 4}. The transmission and emission spectrum of Nd:GdNbO{sub 4} were measured, and the absorption peaks were assigned. The strongest emission peak of Nd:GdNbO{sub 4} is located at 1065.3 nm in the spectral range of 850-1420 nm excited by 808 nm laser. The refractive index of Nd:GdNbO{sub 4} was calculated with the transmission spectrum and fitted with Sellmeier equation. All these obtained results is of great significance for the further research of Nd:GdNbO{sub 4}. (orig.)

Observation of the magnetization-step in Gd doped antiperovskite compounds Mn{sub 3}Cu{sub 1−x}Gd{sub x}N (0.15≤x≤0.25)

Energy Technology Data Exchange (ETDEWEB)

Yuan, Quan [Center for Composite Materials and structures, Harbin Institute of Technology, Harbin 150080 (China); Zhang, Xinghong, E-mail: zhangxh@hit.edu.cn [Center for Composite Materials and structures, Harbin Institute of Technology, Harbin 150080 (China); Gao, Tangling [Institute of Petrochemistry, Heilongjiang Academy of Sciences, Harbin 150040 (China); Zhao, Jinggeng [Department of Physics, Harbin Institute of Technology, Harbin 150080 (China); Academy of Fundamental and Interdisciplinary Sciences, Harbin 150080 (China); Han, Jiecai; Zhou, Shanbao [Center for Composite Materials and structures, Harbin Institute of Technology, Harbin 150080 (China); Hu, Chang; Wang, Xianjie [Department of Physics, Harbin Institute of Technology, Harbin 150080 (China); Zhang, Zhihua [School of Materials Science and Engineering, Dalian Jiaotong University, Dalian 116028 (China); Song, Bo, E-mail: songbo@hit.edu.cn [Center for Composite Materials and structures, Harbin Institute of Technology, Harbin 150080 (China); Department of Physics, Harbin Institute of Technology, Harbin 150080 (China); Academy of Fundamental and Interdisciplinary Sciences, Harbin 150080 (China)

2017-04-15

(Gadolinium) Gd-doped antiperovskite compounds Mn{sub 3}Cu{sub 1−x}Gd{sub x}N were synthesized by the conventional solid-state reaction. With increasing Gd concentration, two magnetic transitions appeared at a high Curie temperature (T{sub C1}) corresponding to paramagnetic (PM)-ferromagnetic (FM) transition and a low temperature (T{sub C2}) ascribed to the FM-antiferromagnetic (AFM) transition. The magnetic relaxation results show the formation of a magnetic metastable state after the FM-AFM transition at low temperature (lower than T{sub C2}), forming a novel magnetic-step feature in the process from AFM to FM under a certain magnetic field. - Highlights: • For the first time, a novel magnetization-step features were revealed in Mn-based antiperovskite compounds. • This study not only benefits us to understand the intrinsic origin of two magnetic transitions after Gd doped, but also paves the way for the design and fabrication of new antiperovskite nitrides with different magnetic state and transition temperature for practical applications. • Two-step magnetic transition were induced by doping Gd element. • The process from AFM to FM in the magnetization-step is irreversible, which is different from that observed in other materials.

Structural and superconducting properties of (Y,Gd)Ba2Cu3O7-δ grown by MOCVD on samarium zirconate buffered IBAD-MgO

International Nuclear Information System (INIS)

Stan, L; Holesinger, T G; Maiorov, B; Feldmann, D M; Usov, I O; DePaula, R F; Civale, L; Foltyn, S R; Jia, Q X; Chen, Y; Selvamanickam, V

2008-01-01

Textured samarium zirconate (SZO) films have been grown by reactive cosputtering directly on an ion beam assisted deposited (IBAD) MgO template, without an intermediate homoepitaxial MgO layer. The subsequent growth of 0.9 μm thick (Y,Gd)Ba 2 Cu 3 O 7-δ ((Y, Gd)BCO) films by metal organic chemical vapor deposition (MOCVD) yielded well textured films with a full width at half maximum of 1.9 0 and 3.4 0 for the out-of-plane and in-plane texture, respectively. Microstructural characterizations of the SZO buffered samples revealed clean interfaces. This indicates that the SZO not only provides a diffusion barrier, but also functions as a buffer for (Y, Gd)BCO grown by MOCVD. The achievement of self-field critical current densities (J c ) of over 2 MA cm -2 at 75.5 K is another proof of the effectiveness of SZO as a buffer on the IBAD-MgO template. The in-field measurements revealed an asymmetric angular dependence of J c and a shift of the ab-plane maxima due to the tilted nature of the template and (Y,Gd) 2 O 3 particles existing in the (Y, Gd)BCO matrix. The present results are especially important because they demonstrate that high temperature superconducting coated conductors with simpler architecture can be fabricated using commercially viable processes

Optimizing the Relaxivity of MRI Probes at High Magnetic Field Strengths With Binuclear GdIII Complexes

Directory of Open Access Journals (Sweden)

Loredana Leone

2018-05-01

Full Text Available The key criteria to optimize the relaxivity of a Gd(III contrast agent at high fields (defined as the region ≥ 1.5 T can be summarized as follows: (i the occurrence of a rotational correlation time τR in the range of ca. 0.2–0.5 ns; (ii the rate of water exchange is not critical, but a τM < 100 ns is preferred; (iii a relevant contribution from water molecules in the second sphere of hydration. In addition, the use of macrocycle-based systems ensures the formation of thermodynamically and kinetically stable Gd(III complexes. Binuclear Gd(III complexes could potentially meet these requirements. Their efficiency depends primarily on the degree of flexibility of the linker connecting the two monomeric units, the absence of local motions and the presence of contribution from the second sphere water molecules. With the aim to maximize relaxivity (per Gd over a wide range of magnetic field strengths, two binuclear Gd(III chelates derived from the well-known macrocyclic systems DOTA-monopropionamide and HPDO3A (Gd2L1 and Gd2L2, respectively were synthesized through a multistep synthesis. Chemical Exchange Saturation Transfer (CEST experiments carried out on Eu2L2 at different pH showed the occurrence of a CEST effect at acidic pH that disappears at neutral pH, associated with the deprotonation of the hydroxyl groups. Then, a complete 1H and 17O NMR relaxometric study was carried out in order to evaluate the parameters that govern the relaxivity associated with these complexes. The relaxivities of Gd2L1 and Gd2L2 (20 MHz, 298 K are 8.7 and 9.5 mM−1 s−1, respectively, +77% and +106% higher than the relaxivity values of the corresponding mononuclear GdDOTAMAP-En and GdHPDO3A complexes. A significant contribution of second sphere water molecules was accounted for the strong relaxivity enhancement of Gd2L2. MR phantom images of the dinuclear complexes compared to GdHPDO3A, recorded at 7 T, confirmed the superiority of Gd2L2. Finally, ab initio

Luminescence and spectroscopic investigations on Gd3+ doped ZnO nanophosphor

Directory of Open Access Journals (Sweden)

G. Krishna Reddy

2017-09-01

Full Text Available The present paper describes the synthesis of 0.1 mol% Gadolinium (Gd doped Zinc oxide (ZnO nanophosphor by solution combustion method using Oxalyl dihydrazide (ODH fuel. Powder X-ray diffraction (PXRD peaks are well matched with the standard hexagonal wurtzite structure of ZnO (JCPDS card no. 36-1451. SEM and TEM analysis reveals porous morphology of as -formed sample with particles having narrow size distribution in the range ∼60–70 nm, in good agreement with XRD data. The PL spectrum of Gd doped ZnO sample exhibits an extra blue emission at 441 nm (∼2.81 eV in addition to the emission bands from undoped ZnO. From the TL data of ZnO:Gd nanophosphor with UV irradiation, it is observed that considerable amount of re-trapping is taking place in all the TL second order peaks. The EPR spectrum exhibits a number of resonance signals suggesting that Gd3+ ions are experiencing different crystal field strength and Zeeman interactions.

Perpendicular exchange coupling effects in ferrimagnetic TbFeCo/GdFeCo hard/soft structures

Science.gov (United States)

Wang, Ke; Wang, Yahong; Ling, Fujin; Xu, Zhan

2018-04-01

Bilayers consisting of magnetically hard TbFeCo and soft GdFeCo alloy were fabricated. Exchange-spring and sharp switching in a step-by-step fashion were observed in the TbFeCo/GdFeCo hard/soft bilayers with increasing GdFeCo thickness. A perpendicular exchange bias field of several hundred Oersteds is observed from the shift of minor loops pinned by TbFeCo layer. The perpendicular exchange energy is derived to be in the range of 0.18-0.30 erg/cm2. The exchange energy is shown to increase with the thickness of GdFeCo layer in the bilayers, which can be attributed to the enhanced perpendicular anisotropy of GdFeCo layer in our experimental range.

A novel cryogenic magnetic refrigerant metal-organic framework based on 1D gadolinium(III) chain

Energy Technology Data Exchange (ETDEWEB)

Tang, Qun; Li, Peng-Fei [Guangxi Key Laboratory of Electrochemical and Magneto-chemical Functional Materials, College of Chemistry and Bioengineering, Guilin University of Technology, Guilin, Guangxi 541004 (China); Zou, Zhi-Ming, E-mail: 2014005@glut.edu.cn [Guangxi Key Laboratory of Electrochemical and Magneto-chemical Functional Materials, College of Chemistry and Bioengineering, Guilin University of Technology, Guilin, Guangxi 541004 (China); Liu, Zheng [Guangxi Key Laboratory of Electrochemical and Magneto-chemical Functional Materials, College of Chemistry and Bioengineering, Guilin University of Technology, Guilin, Guangxi 541004 (China); Liu, Shu-Xia, E-mail: liusx@nenu.edu.cn [Key Laboratory of Polyoxometalate Science of Ministry of Education, College of Chemistry, Northeast Normal University, Changchun, Jilin 130024 (China)

2017-02-15

A metal-organic framework (MOF) based on gadolinium ion (Gd{sup 3+}) and tricarboxylate ligand, [Gd(BTPCA)(H{sub 2}O)]·2DMF·3H{sub 2}O (Gd-BTPCA) (H{sub 3}BTPCA =1,1′,1′-(benzene-1,3,5-triyl)tripiperidine-4-carboxylic acid; DMF=dimethylformamide), was synthesized and structurally characterized. The adjacent Gd{sup 3+} ions are intraconnected by the carboxylate groups of the BTPCA{sup 3-} ligands to form a 1D Gd{sup 3+} ion chain. The 1D Gd{sup 3+} ion chains are interconnected by the BTPCA{sup 3-} ligands, giving rise to a 3D framework with 1D open channel. The magnetic studies indicate that Gd-BTPCA exhibits weak ferromagnetic interactions, and acts as a cryogenic magnetic refrigerant having the magnetic entropy change (−ΔS{sub m}) of 20.40 J kg{sup −1} K{sup −1} for ΔH =7 T at 3 K. - Graphical abstract: A 1D gadolinium(III) chains-based metal-organic framework performed ferromagnetic coupling on the magnetic property. Magnetic investigation reveals that Gd-BTPCA exhibits the entropy change (−ΔS{sub m}) of 20.40 J kg{sup −1} K{sup −1} for ΔH =7 T at 3 K. - Highlights: • The MOF based on gadolinium ion and tricarboxylate ligand was synthesized. • This MOF is connected with 1D Gd{sup 3+} ions chain and the carboxylate groups of BTPCA{sup 3-} ligands. • The magnetic studies indicate that the MOF exhibits the weak ferromagnetic interactions. • Magnetic investigation reveals that the MOF exhibits the high entropy change.

Photoluminescence and thermoluminescence properties of Tb3+ doped K3Gd(PO4)2 nanophosphor

International Nuclear Information System (INIS)

Gupta, Palvi; Bedyal, A.K.; Kumar, Vinay; Khajuria, Y.; Lochab, S.P.; Pitale, S.S.; Ntwaeaborwa, O.M.; Swart, H.C.

2014-01-01

Energy level diagram of Tb 3+ ion in the K 3 Gd(PO 4 ) 2 host lattice. - Highlights: • First time, a detailed TL and PL study on undoped and Tb 3+ doped K 3 Gd(PO 4 ) 2 nanophosphor. • Combustion method was employed to synthesize the Tb 3+ doped K 3 Gd(PO 4 ) 2 nanophosphor. • Mechanism of excitation and emission in undoped and Tb 3+ doped K 3 Gd(PO 4 ) 2 nanophosphor was given. - Abstract: Tb 3+ doped nanoparticulate K 3 Gd(PO 4 ) 2 phosphor was prepared by combustion method using urea as a fuel. The structure, optical and luminescent properties of the phosphor were studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), diffuse reflectance spectroscopy (DRS), photoluminescence spectroscopy (PL), and thermoluminescence (TL) spectroscopy. In undoped K 3 Gd(PO 4 ) 2 , the excitation and emission peaks at 273 nm and 323 nm belongs to the 8 S 7/2 → 6 I J(J=7/2) and 6 P J(J=7/2) → 8 S 7/2 transitions of Gd 3+ while green emission was observed in the Tb 3+ doped K 3 Gd(PO 4 ) 2 . TL study was carried out after exposing the samples to γ-radiations (0.1–5 kGy) in the K 3 Gd(PO 4 ) 2 :Tb 3+ (1.5 mol%). The calculated kinetic parameters were compared with different methods. The band gap of the phosphor was estimated as 5.80 eV. The green shade of the Tb 3+ ion with the CIE coordinates (x, y) as (0.29, 0.54) was in good agreement with the well known green phosphors

Development of Gd(III) porphyrin-conjugated chitosan nanoparticles as contrast agents for magnetic resonance imaging

Energy Technology Data Exchange (ETDEWEB)

Jahanbin, Tania [Université Paul Sabatier, Toulouse III, INSERM U825, CHU Purpan, 31059 Toulouse Cedex 9 (France); Sauriat-Dorizon, Hélène [Institut de Chimie Moléculaire et des Matériaux d' Orsay, UMR CNRS 8182, ECBB, Université Paris-Sud, 91405 Orsay (France); Spearman, Peter [Faculty of Science, Engineering and Computing, University of Kingston, Penrhyn Road Kingston upon Thames Surrey KT1 2EE, London (United Kingdom); Benderbous, Soraya, E-mail: soraya.benderbous@univ-tlse3.fr [Université Paul Sabatier, Toulouse III, INSERM U825, CHU Purpan, 31059 Toulouse Cedex 9 (France); Korri-Youssoufi, Hafsa, E-mail: hafsa.korri-youssoufi@u-psud.fr [Institut de Chimie Moléculaire et des Matériaux d' Orsay, UMR CNRS 8182, ECBB, Université Paris-Sud, 91405 Orsay (France)

2015-07-01

A novel magnetic resonance imaging (MRI) contrast agent based on gadolinium meso-tetrakis(4-pyridyl)porphyrin [Gd(TPyP)] conjugated with chitosan nanoparticles has been developed. The chitosan nanoparticles were synthesized following an ionic gelation method and the conditions optimized to generate small nanoparticles (CNs) with a narrow size distribution of 35–65 nm. The gadolinium meso-tetrakis(4-pyridyl)porphyrin [Gd(TPyP)] was loaded into chitosan nanoparticles by passive adsorption. The interaction of chitosan with Gd(TPyP) has been examined by UV–visible, Fourier transform infrared spectroscopies (FT-IR) and inductively coupled plasma mass spectrometry (ICP-MS), which indicate the successful association of Gd(TPyP) without any structural distortion throughout the chitosan nanoparticles. The potential of Gd(TPyP)-CNs as MRI contrast agent has been investigated by magnetic resonance imaging (MRI) in-vitro. Relaxivities of Gd(TPyP)-CNs obtained from T{sub 1}-weighted images, increased with Gd concentration and attained an optimum r{sub 1} of 38.35 mM{sup −1} s{sup −1}, which is 12-fold higher compared to commercial Gd-DOTA (~ 4 mM{sup −1} s{sup −1} at 3T). The combination of such strong MRI contrast with the known properties of porphyrins in photodynamic therapy and biocompatibility of chitosan, presents a new perspective in using these compounds in cancer theranostics. - Highlights: • Synthesis of chitosan nanoparticles with small size • Study of loading properties with gadolinium porphyrins • In vitro properties of the conjugated complex as contrast agent for MRI imaging • Comparison of MRI properties with commercial contrast agent Gd-DOTA.

Glypican-1-antibody-conjugated Gd-Au nanoclusters for FI/MRI dual-modal targeted detection of pancreatic cancer.

Science.gov (United States)

Huang, Xin; Fan, Chengqi; Zhu, Huanhuan; Le, Wenjun; Cui, Shaobin; Chen, Xin; Li, Wei; Zhang, Fulei; Huang, Yong; Sh, Donglu; Cui, Zheng; Shao, Chengwei; Chen, Bingdi

2018-01-01

Pancreatic cancer (PC) has a poor prognosis with high mortality, due to the lack of effective early diagnostic and prognostic tools. In order to target and diagnose PC, we developed a dual-modal imaging probe using Glypican-1 (GPC-1) antibody conjugated with Gd-Au nanoclusters (NCs; Gd-Au-NC-GPC-1). GPC-1 is a type of cell surface heparan sulfate proteoglycan, which is often highly expressed in PC. The probe was successfully prepared with a hydrodynamic diameter ranging from 13.5 to 24.4 nm. Spectral characteristics showed absorption at 280 nm and prominent emission at 650 nm. Confocal microscopic imaging showed effective detection of GPC-1 highly expressed PC cells by Gd-Au-NC-GPC-1, which was consistent with flow cytometry results. In vitro relaxivity characterization demonstrated that the r1 value of the probe was 17.722 s -1 mM -1 Gd, which was almost 4 times higher compared with that of Gd-diethylenetriaminepentacetate (DTPA; r1 value =4.6 s -1 mM -1 Gd). Gd-Au-NC-GPC-1 exhibited similar magnetic resonance (MR) signals when compared to Gd-DTPA even at lower Gd concentrations. Much higher MR signals were registered in PC cells (COLO-357) compared with normal cells (293T). Furthermore, Gd-Au-NC-GPC-1 could effectively detect PC cells in vivo by dual-modal fluorescence imaging/magnetic resonance imaging (FI/MRI) at 30 minutes postinjection. In addition, Gd-Au-NC-GPC-1 did not show significant biotoxicity to normal cells at tested concentrations both in vitro and in vivo. Gd-Au-NC-GPC-1 has demonstrated to be a promising dual-modal FI/MRI contrast agent for targeted diagnosis of PC.

Synthesis, structure and photoluminescence of novel lanthanide (Tb(III), Gd(III)) complexes with 6-diphenylamine carbonyl 2-pyridine carboxylate

International Nuclear Information System (INIS)

An Baoli; Gong Menglian; Cheah, Kok-Wai; Wong, Wai-Kwok; Zhang Jiming

2004-01-01

A novel organic ligand, 6-diphenylamine carbonyl 2-pyridine carboxylic acid (HDPAP), and the corresponding lanthanide complexes, tris(6-diphenylamine carbonyl 2-pyridine carboxylato) terbium(III) (Tb-DPAP) and tris(6-diphenylamine carbonyl 2-pyridine carboxylato) gadolinium(III) (Gd-DPAP) have been designed and synthesized. The crystal structure and photoluminescence of Tb-DPAP and Gd-DPAP have been studied. The results showed that the lanthanide complexes have electroneutral structures, and the solid terbium complex emits characteristic green fluorescence of Tb(III) ions at room temperature while the gadolinium complex emits the DPAP ligand phosphorescence. The lowest triplet level of DPAP ligand was calculated from the phosphorescence spectrum of Gd-DPAP in N,N-dimethyl formamide (DMF) dilute solution determined at 77 K, and the energy transfer mechanisms in the lanthanide complexes were discussed. The lifetimes of the 5 D 4 levels of Tb 3+ ions in the terbium complex were examined using time-resolved spectroscopy, and the values are 0.0153±0.0001 ms for solid Tb(DPAP) 3 ·11.5H 2 O and 0.074±0.007 ms for 2.5x10 -5 mol/l Tb-DPAP ethanol solution

Long Gd-123 coated conductor by PLD method

International Nuclear Information System (INIS)

Fuji, H.; Igarashi, M.; Hanada, Y.; Miura, T.; Hanyu, S.; Kakimoto, K.; Iijima, Y.; Saitoh, T.

2008-01-01

We have developed long Gd-123 coated conductors by ion-beam-assisted deposition (IBAD) and pulsed-laser-deposition (PLD) method. Recently, large-scale reel-to-reel apparatus with the 110 cm x 15 cm assisting ion source was introduced to IBAD system. It was enable to produce 500 m-class IBAD-Gd 2 Zr 2 O 7 (GZO) tapes with Δφ of below 15 deg. and high throughputs of 3 m/h. Furthermore, apparatus with multi-lane and laser scanning was introduced to PLD system. As a result, end to end I c of 318 A were obtained for a 201.5 m long tape, and I c x L values were 64,077 Am. Furthermore, 500 m-class deposition was carried out by improving PLD conditions. As a result, I c x L values of 112,166 Am was obtained and it's a world record on August 2007. In the short samples, I c of over 500 A was obtained with Gd-123 thickness of 2.0 μm and over 100 A was obtained in magnetic field of 3 T, perpendicular to c-axis

Ferromagnetic resonance features of degenerate GdN semiconductor

Energy Technology Data Exchange (ETDEWEB)

Vidyasagar, Reddithota, E-mail: dr.vidyasagar1979@gmail.com [Department of Electrical and Electronic Engineering, Graduate School of Engineering, Kobe University, 1-1 Rokkodai, Kobe 657-8501 (Japan); Kita, Takashi [Department of Electrical and Electronic Engineering, Graduate School of Engineering, Kobe University, 1-1 Rokkodai, Kobe 657-8501 (Japan); Sakurai, Takahiro; Shimokawa, Tokuro [Centre for Support to Research and Education Activities, Kobe University, 1-1 Rokkodai, Kobe 657-8501 (Japan); Ohta, Hitoshi [Molecular Photoscience Research Center and Graduate School of Science, Kobe University, 1-1 Rokkodai, Kobe 657-8501 (Japan)

2017-06-15

Using X-band Ferromagnetic Resonance (FMR) Spectroscopy, we demonstrate the microscopic ferromagnetic resonance features of degenerated GdN semiconductor. The FMR spectrum suggests a single resonance mode below 10 K; interestingly, this particular structure is found to exhibit a peculiar magnetic resonance (PMR) on the top of the uniform FMR while temperature increases from 12–36 K. The low-field PMR mode attributed to the differently magnetized part of the film with an easy in-plane axis. The narrow-field gap between PMR and uniform FMR suggests the strong coupling owning to the differently magnetized part with easy in-plane axis and the magnetized part with an out-of-plane axis. The saturation magnetization, cubic magnetocrystalline anisotropy, and uniaxial anisotropy of GdN epitaxial film have been evaluated by the angular-dependence FMR. - Highlights: • Observation of peculiar magnetic resonance (PMR) on the top of ferromagnetic resonance (FMR). • Newly evolving PMR manifests differently magnetized part of the film with an easy in-plane axis. • Narrow gap between PMR and FMR owing to the strong interaction between two spin–wave resonances. • Uniaxial anisotropy increases with GdN thickness decreases.

Structure and magnetic transport properties of GdIn{sub 3−x}Mn{sub x} intermetallics

Energy Technology Data Exchange (ETDEWEB)

He, Qiang; Guo, Yongquan, E-mail: yqguo@ncepu.edu.cn; Liu, Hanyuan

2016-03-01

The crystal structures and magneto-transport properties of GdIn{sub 3−x}Mn{sub x} have been investigated using X-ray diffraction and magnetic and electric measurements. GdIn{sub 3−x}Mn{sub x} crystallize in cubic structure, and their lattice parameters tend to decrease with increasing Mn content due to the size effect at In site by Mn substitution for In. Mn doped GdIn{sub 3−x}Mn{sub x} order antiferromagnetically at low temperature. However, Mn doping into GdIn{sub 3} causes the decrease of Néel temperature due to the distortion of Gd(In,Mn){sub 3} tetrahedron formed by Gd at corners and (In,Mn) at face centers in unit cell. The resistivities of GdIn{sub 3−x}Mn{sub x} are going up with increasing Mn content. The electric phase transition is associated with the magnetic transition, and the magneto-transport follows electron–magnon scattering model in low temperature region and the Stoner spin fluctuation model in high temperature region, respectively. - Highlights: • Novel GdIn{sub 3−x}Mn{sub x} intermetallic compounds have been successfully prepared. • The lattice parameters tend to decrease with increasing Mn content. • GdIn{sub 3−x}Mn{sub x} orders antiferromagnetically at low temperature. • The strong correlation between the electric transport and magnetic state is observed.

Recent developments in melt processed Gd-123 and MgB2 materials at RTRI

International Nuclear Information System (INIS)

Muralidhar, M.; Fukumoto, Y.; Ishihara, A.; Suzuki, K.; Tomita, M.; Koblischka, M.R.; Yamamoto, A.; Kishio, K.

2014-01-01

Highlights: •Large size Gd-123 bulk material grown in air, using novel thin film Nd-123 seeds grown on MgO crystals. •Quality and uniformity of the Gd-123 materials are excellent. •Batch processed Gd-123 material was used for construction of chilled Maglev vehicle. •MgB 2 bulks can be utilized around 20 K similarly to the Gd-123 material at 77 K. -- Abstract: In this contribution we will report on the current status, recent developments in GdBa 2 Cu 3 O y “Gd-123” and MgB 2 material processing, characterization, and applications at the Railway Technical Research Institute (RTRI). Batch-processing of Gd-123 bulk material grown in air was performed using novel thin film Nd-123 seeds grown on MgO crystals. In this way, we are able to fabricate materials with good quality, and uniform performance. We examined the technology of the uniform performance of the large 45 mm diameter, single grain Gd-123 bulks for use in application of NMR. For this purpose, four 5 mm thick pieces are cut vertically from a single grain Gd-123 material and the magnetic field distribution is measured using a scanning hall sensor. We found that all four pieces are single domain and exhibit a quite uniform field distribution. Furthermore, the batch-processed bulk materials are used for the construction of a chilled Maglev vehicle. On the other hand, to optimize the trapped field performance of bulk MgB 2 material, several samples were prepared by solid state reaction at different temperatures ranging from 750 to 950 °C in pure argon atmosphere. X-ray diffraction results indicated that single phase and homogenous MgB 2 bulks are produced when sintering them around 775 °C. Further, atomic force microscopy (AFM) and scanning electron microscopy (SEM) indicated that an uniform grain size results by controlling the processing temperature. So, higher trapped fields can be achieved in sintered MgB 2 material

Wetting behaviour and reactivity between liquid Gd and ZrO2 substrate

Directory of Open Access Journals (Sweden)

Turalska P.

2017-01-01

Full Text Available The wetting behavior and reactivity between molten pure Gd and polycrystalline 3YSZ substrate (ZrO2 stabilized with 3 wt% of Y2O3were experimentally determined by a sessile drop method using a classical contact heating coupled with drop pushing procedure. The test was performed under an inert flowing gas atmosphere (Ar at two temperatures of 1362°C and 1412°C. Immediately after melting (Tm=1341°C, liquid Gd did not wet the substrate forming a contact angle of θ=141°. The non-wetting to wetting transition (θ < 90° took place after about 110 seconds of interaction and was accompanied by a sudden decrease in the contact angle value to 67°. Further heating of the couple to 1412 °C did not affect wetting (θ=67°±1°. The solidified Gd/3YSZ couple was studied by means of optical microscopy and scanning electron microscopy coupled with X-ray energy dispersive spectroscopy. Structural investigations revealed that the wettability in the Gd/3YSZ system is of a reactive nature associated with the formation of a continuous layer of a wettable reaction product Gd2Zr2O7.

GD-OES and XPS coupling: A new way for the chemical profiling of photovoltaic absorbers

Energy Technology Data Exchange (ETDEWEB)

Mercier, Dimitri, E-mail: dimitri.mercier@uvsq.fr [Institut Lavoisier de Versailles, 45 av. des Etats-Unis, 78035 Versailles Cedex (France); Bouttemy, Muriel; Vigneron, Jackie [Institut Lavoisier de Versailles, 45 av. des Etats-Unis, 78035 Versailles Cedex (France); Chapon, Patrick [HORIBA Jobin Yvon SAS, F-91165 Longjumeau (France); Etcheberry, Arnaud [Institut Lavoisier de Versailles, 45 av. des Etats-Unis, 78035 Versailles Cedex (France)

2015-08-30

Highlights: • The coupling between GD-OES and XPS analysis is a promising way for fine characterization of thin layers. • Crater surface modifications obtained after GD-OES sputtering depend to the plasma gas. • Inversion of the gas flow improves the surface of the crater. • The modified layer is totally eliminated a few seconds after restarting GD-OES sputtering. - Abstract: In this paper, we examine the complementarity of Glow Discharge Optical Emission Spectroscopy (GD-OES) and X Ray Photoelectron Spectroscopy (XPS) for the realization of fine chemical depth profiling of photovoltaic absorbers using Cu(In,Ga)Se{sub 2} (CIGS) materials. The possibility to use sequentially these two techniques is discussed in this paper. We have evaluated the chemical modifications of the crater after GD-OES analyses which depend on the manner of finishing the plasma etching sequence; and we propose different ways to limit or eliminate this effect. For the moment, an intermediate step (wet chemical etching or weak sputtering) is required to obtain a CIGS phase in the crater. Finally, we have demonstrated the possibility to restart the GD-OES analyses of the materials after XPS quantification or GD-OES breaking without modifying the profile shape.

External electric field effects on Schottky barrier at Gd3N@C80/Au interface

Science.gov (United States)

Onishi, Koichi; Nakashima, Fumihiro; Jin, Ge; Eto, Daichi; Hattori, Hayami; Miyoshi, Noriko; Kirimoto, Kenta; Sun, Yong

2017-08-01

The effects of the external electric field on the height of the Schottky barrier at the Gd3N@C80/Au interface were studied by measuring current-voltage characteristics at various temperatures from 200 K to 450 K. The Gd3N@C80 sample with the conduction/forbidden/valence energy band structure had a face-centered cubic crystal structure with the average grain size of several nanometers. The height of the Gd3N@C80/Au Schottky barrier was confirmed to be 400 meV at a low electric field at room temperature. Moreover, the height decreases with the increasing external electric field through a change of permittivity in the Gd3N@C80 sample due to a polarization of the [Gd3] 9 +-[N3 -+("separators="|C80 ) 6 -] dipoles in the Gd3N@C80 molecule. The field-dependence of the barrier height can be described using a power math function of the electric field strength. The results of the field-dependent barrier height indicate that the reduction in the Schottky barrier is due to an image force effect of the transport charge carrier at the Gd3N@C80/Au interface.

Angular correlation and lifetime measurements in /sup 154/Gd

Energy Technology Data Exchange (ETDEWEB)

Sharma, A K; Verma, H R; Kaur, R; Sooch, S S; Trehan, P N

1982-03-01

Multipole admixtures in 591.80, 692.51, 723.38, 756.84, 873.27, 1004.74, 1274.50, 1494.22 and 1596.65 keV transitions have been measured by investigating nine gamma-gamma angular correlations in /sup 154/Gd. The present study confirms very small Ml admixtures in the transitions from ..beta..- and ..gamma..-vibrational bands to ground state band in /sup 154/Gd which is a transitional nucleus. In addition, lifetime of an excited level at 123.04 keV has been measured to be 1.19 +- 0.03 nsec.

Double ferromagnetism in single-crystal Gd-Y-Lu alloys

International Nuclear Information System (INIS)

Ito, T.; Oka, M.; Legvold, S.; Beaudry, B.J.

1984-01-01

Magnetization, electrical resistivity, specific-heat and thermal-expansion measurements have been made on Gd-Y-Lu single crystals. Low isofield magnetization data for the a-axis sample of Gd 75 Y/sub 17.5/ Lu/sub 7.5/ exhibit two different Curie-Weiss regimes, which suggests double ferromagnetism. Electrical resistivity, specific-heat, and thermal-expansion data show two anomalies at the transition temperatures. The anomaly at 231.5 K shows a lambda-type second-order phase transition and the anomaly at 223 K shows a sharp spike first-order phase transition

Data of evolutionary structure change: 1RAAA-3GD5C [Confc[Archive

Lifescience Database Archive (English)

Full Text Available 1RAAA-3GD5C 1RAA 3GD5 A C ANPLYQKHIISINDLSRDDLNLVLATAAKLKANPQPELL...LRDPFEAARGAHILYTDVWTHRLQLFEQYQINAALLN--------------CAAAEAIVLHCLPAHRGEEITDEVMEGPRS... 0 1RAA A 1RAAAA 1RAAA PLPRV--DEIAT...Chain> 1RAA A 1RAAA

A comprehensive investigation of tetragonal Gd-doped BiVO{sub 4} with enhanced photocatalytic performance under sun-light

Energy Technology Data Exchange (ETDEWEB)

Luo, Yangyang; Tan, Guoqiang, E-mail: tan3114@163.com; Dong, Guohua; Ren, Huijun; Xia, Ao

2016-02-28

Graphical abstract: - Highlights: • Tetragonal Gd-BiVO{sub 4} with enhanced photocatalytic activity was synthesized. • Gd doping can induce the phase transition from monoclinic to tetragonal BiVO{sub 4}. • GdVO{sub 4} seeds as crystal nucleus dominate the formation of tetragonal Gd-BiVO{sub 4}. • Tetragonal Gd-BiVO{sub 4} exhibits the excellent separation of electrons and holes. • The contribution of high photocatalytic activity under sun-light is from UV-light. - Abstract: Tetragonal Gd-doped BiVO{sub 4} having enhanced photocatalytic activity have been synthesized by a facile microwave hydrothermal method. The structural analysis indicates that Gd doping can induce the phase transition from monoclinic to tetragonal BiVO{sub 4}. The reaction results in precursor solutions imply that tetragonal GdVO{sub 4} seeds as crystal nucleus are the original and determined incentives to force the formation of tetragonal Gd-BiVO{sub 4}. The influences of the surface defect, band structure, and BET surface area on the improved photocatalytic activities of tetragonal Gd-doped BiVO{sub 4} are investigated systematically. The results demonstrate that the more surface oxygen deficiencies as active sites and the excellent mobility and separation of photogenerated electrons and holes are beneficial to the enhancement of the photocatalytic performance of tetragonal Gd-BiVO{sub 4}. The RhB photodegradation experiments indicate that the contribution of high photocatalytic activities under simulated sun-light is mainly from UV-light region due to the tetragonal structure feature. The best photocatalytic performance is obtained for tetragonal 10 at% Gd-BiVO{sub 4}, of which the RhB degradation rate can reach to 96% after 120 min simulated sun-light irradiation. The stable tetragonal Gd-BiVO{sub 4} with efficient mineralization will be a promising photocatalytic material applied in water purification.

Hydrothermal synthesis of Gd2O3:Eu3+ nanophosphors: Effect of surfactant on structural and luminescence properties

International Nuclear Information System (INIS)

Dhananjaya, N.; Nagabhushana, H.; Sharma, S.C.; Rudraswamy, B.; Shivakumara, C.; Nagabhushana, B.M.

2014-01-01

Highlights: • Gd(OH) 3 :Eu 3+ , GdOOH:Eu 3+ and Gd 2 O 3 :Eu 3+ phases were prepared by hydrothermal method. • Phosphors were well characterized by XRD, SEM, TEM, Raman, UV–Vis, FT-IR. • Cubic Gd 2 O 3 :Eu 3+ show intense red emission, which was highly useful for photonics application. • HDA surfactant plays an important role in conversion of cubic to hexagonal phases. -- Abstract: Various morphologies of Eu 3+ activated gadolinium oxide have been prepared by hydrothermal method using hexadecylamine (HDA) as surfactant at different experimental conditions. The powder X-ray diffraction studies reveal as-formed product is hexagonal Gd(OH) 3 :Eu 3+ phase and subsequent heat treatment at 350 and 600 °C transforms to monoclinic GdOOH:Eu 3+ and cubic Gd 2 O 3 :Eu 3+ phases respectively. SEM pictures of without surfactant show irregular shaped rods along with flakes. However, in the presence of HDA surfactant, the particles are converted into rods of various sizes. The temperature dependent morphological evolution of Gd 2 O 3 :Eu 3+ without and with HDA surfactant is studied. TEM micrographs of Gd(OH) 3 :Eu 3+ sample with HDA confirms smooth nanorods with various diameters in the range 20–100 nm. FTIR studies reveal that HDA surfactant plays an important role in conversion of cubic to hexagonal phases. Among these three phases, cubic phase Gd 2 O 3 :Eu 3+ (λ ex = 254 nm) show red emission at 612 nm corresponding to 5 D 0 → 7 F 2 and is more efficient host than the monoclinic counterpart. The band gap for hexagonal Gd(OH) 3 :Eu 3+ is more when compared to monoclinic GdOOH:Eu 3+ and cubic Gd 2 O 3 :Eu 3+

Influence of gadolinium concentration on the EMR spectrum of Gd{sup 3+} in zircon

Energy Technology Data Exchange (ETDEWEB)

Biasi, R.S. de, E-mail: rsbiasi@ime.eb.b [Secao de Engenharia Mecanica e de Materiais, Instituto Militar de Engenharia, 22290-270 Rio de Janeiro, RJ (Brazil); Grillo, M.L.N., E-mail: mluciag@uerj.b [Instituto de Fisica, Universidade do Estado do Rio de Janeiro, 20550-013 Rio de Janeiro, RJ (Brazil)

2009-11-01

Electron magnetic resonance (EMR) spectra of gadolinium-doped zircon (ZrSiO{sub 4}) powders have been studied at room temperature for gadolinium concentrations between 0.20 and 1.0 mol%. The results suggest that Gd{sup 3+} ions occupy substitutional sites in the zircon lattice, that the electron magnetic resonance linewidth increases with increasing gadolinium concentration and that the range of the exchange interaction between Gd{sup 3+} ions is about 1.17 nm, larger than that of the same ion in other host lattices, such as ceria (CeO{sub 2}), strontium oxide (SrO) and calcium oxide (CaO). The fact that the electron magnetic resonance linewidth of the Gd{sup 3+} ion in polycrystalline zircon increases, regularly and predictably, with Gd concentration, shows that the Gd{sup 3+} ion can be used as a probe to study, rapidly and non-destructively, the crystallinity and degradation of ZrSiO{sub 4}.

Enteropathogenic bacterial contamination of a latosol following application of organic fertilizer

Directory of Open Access Journals (Sweden)

Pedro Alexandre Escosteguy

2015-10-01

Full Text Available Poultry manure is used as fertilizer in natura, but little is known about whether it contaminates the soil with pathogenic organisms. The aim of this study was to assess the effects of organic, organomineral and mineral fertilizers on soil contamination by enteric pathogens, using poultry manure as the organic fertilizer. Manure was applied in field experiments at rates of 7.0 ton. ha-1 (maize crop, 2008/2009, 8.0 ton. ha-1 (wheat crop, 2009 and 14 ton. ha-1 (maize crop, 2010/2011. Organomineral fertilizer was applied at the same rates but was comprised of 50% manure and 50% mineral fertilizer. At 30 and 70 days after fertilization, the organic fertilizer and the upper 0-5 cm layer of the soil were tested for the presence of helminth eggs and larvae and enteropathogenic bacteria. Fecal and non-fecal coliforms (Escherichia coli and Clostridium perfringes were found in the organic fertilizer, but neither Salmonella spp. nor enteroparasites were detected. The population of enteropathogenic bacteria in the soil was similar among the treatments for all crops at both evaluation times. The population of thermotolerant coliforms in the organic fertilizer was larger than the maximum level allowed in Brazil, but neither the organic or nor the organomineral fertilizer contaminated the soil.

Responsible for 45 000 tons CO2 emissions

International Nuclear Information System (INIS)

Nedrelid, Ola N.

2006-01-01

Waste combustion has much better tax conditions in Sweden compared to Norway. Today waste is being transported from Norway to Sweden, resulting in a 45 000 ton emission of CO 2 every year, when the waste could have remained in Norway, utilized as regained energy in district heating. The tax regime, however, does not provide the conditions for a profitable use of the waste in Norway. The district heating association is disappointed with the new government's proposed fiscal budget, which only worsens the competitive situation for Norway handling its own waste (ml)

Phase analysis and magnetocaloric properties of Zr substituted Gd-Si-Ge alloys

International Nuclear Information System (INIS)

Prabahar, K.; Raj Kumar, D.M.; Manivel Raja, M.; Chandrasekaran, V.

2011-01-01

The structure, microstructure, magneto-structural transition and magnetocaloric effect have been investigated in series of (Gd 5-x Zr x )Si 2 Ge 2 alloys with 0≤x≥0.20. X-ray powder diffraction analysis revealed the presence of orthorhombic structure for Zr containing alloys at room temperature in contrast to the monoclinic structure observed in the parent Gd 5 Si 2 Ge 2 alloy. The microstructural studies reveal that, low Zr addition (x≤0.1) resulted in low volume fraction of detrimental Gd 5 Si 3 -type secondary phase compared to that present in the parent alloy. All the Zr containing alloys have shown the presence of only second order magnetic transition unlike the parent alloy showing both first order structural and second order magnetic transition. A moderate (ΔS) M value of -5.5 J/kg K was obtained for the x=0.05 alloy at an enhanced operating temperature of 292 K compared to -7.8 J/kg K at 274 K of the parent alloy for an applied field of 2 T. The interesting feature of Zr (x=0.05) containing alloy is the wide operating temperature range of ∼25 K than that of ∼10-12 K for the parent, which resulted in enhanced net refrigerant capacity of 103 J/kg compared to that of 53 J/kg for the parent alloy. - Research highlights: → Zr addition in Gd 5 Si 2 Ge 2 alloy has been investigated for the first time to reduce the 5:3-type (Gd 5 Si 3 ) secondary phase formed when using commercial grade elements in Gd 5 Si 2 Ge 2 alloy. → It is interesting to observe that Zr addition decrease the volume fraction 5:3. → The refrigerator capacity and transition temperature of Zr added alloy is greater than the pure Gd 5 Si 2 Ge 2 which makes this alloy promising for room temperature application.

Fabrication of single-grain GdBa 2 Cu 3 O 7− bulk ...

Indian Academy of Sciences (India)

Research Articles Volume 74 Issue 5 May 2010 pp 827-832 ... Superconductors; top seeded infiltration and growth process; GdBa2 ... The morphology, microstructure and levitation force of the bulk GdBCO have also been investigated.

Gd(iii)-doped carbon dots as a dual fluorescent-MRI probe

KAUST Repository

Bourlinos, Athanasios B.; Bakandritsos, Aristides; Kouloumpis, Antonios; Gournis, Dimitrios; Krysmann, Marta; Giannelis, Emmanuel P.; Polakova, Katerina; Safarova, Klara; Hola, Katerina; Zboril, Radek

2012-01-01

We describe the synthesis of Gd(iii)-doped carbon dots as dual fluorescence-MRI probes for biomedical applications. The derived Gd(iii)-doped carbon dots show uniform particle size (3-4 nm) and gadolinium distribution and form stable dispersions in water. More importantly, they exhibit bright fluorescence, strong T1-weighted MRI contrast and low cytotoxicity. © The Royal Society of Chemistry 2012.

Structural and dielectric properties of Gd doped bismuth ferrite-lead titanate

International Nuclear Information System (INIS)

Mohanty, N. K.; Behera, A. K.; Satpathy, S. K.; Behera, B.; Nayak, P.

2014-01-01

0.5BiGd x Fe 1−x O 3 −0.5PbTiO 3 with x=0.05, 0.10, 0.15, 0.20 composite was prepared by mixed oxide method. Structural characterization was performed by X-ray diffraction and studied that the materials show tetragonal structure at room temperature for all concentration of Gd. Studies of dielectric properties (ε r and tanδ) of the above compound at different frequencies in a wide range of temperature (25°-500°C) with an impedance analyser revealed that the dielectric constant increases with increase in Gd concentration as well temperature and the compound do not have any dielectric anomaly in the studied frequency and temperature range

Application of a dynamic-nanoindentation method to analyze the local structure of an Fe-18 at.% Gd cast alloy

Energy Technology Data Exchange (ETDEWEB)

Choi, Yong; Baik, Youl [Dept. of Materials Science and Technology, Dankook University, Cheonan(Korea, Republic of); Moon, Byung M. [Liquid Processing and Casting Technology R and D Group, KITECH, Incheon (Korea, Republic of); Sohn, Dong Seong [Nuclear Engineering Department, UNIST, Ulsan (Korea, Republic of)

2017-04-15

A dynamic nanoindentation method was applied to study an Fe-18 at.% Gd alloy as a neutron-absorbing material prepared by vacuum arc-melting and cast in a mold. The Fe-18 at.% Gd cast alloy had a microstructure with matrix phases and an Fe-rich primary dendrite of Fe9Gd. Rietveld refinement of the X-ray spectra showed that the Fe-18 at.% Gd cast alloy consisted of 35.84 at.% Fe3Gd, 6.58 at.% Fe5Gd, 16.22 at.% Fe9Gd, 1.87 at.% Fe2Gd, and 39.49 at.% β-Fe17Gd2. The average nanohardness of the primary dendrite phase and the matrix phases were 8.7 GPa and 9.3 GPa, respectively. The fatigue limit of the matrix phase was approximately 37% higher than that of the primary dendrite phase. The dynamic nanoindentation method is useful for identifying local phases and for analyzing local mechanical properties.

Electronic and magnetic structures of GdS layers investigated by first principle and series expansions calculations

International Nuclear Information System (INIS)

Masrour, R.; Hlil, E.K.; Hamedoun, M.; Benyoussef, A.

2014-01-01

Self-consistent ab initio calculations, based on Density Functional Theory (DFT) approach and using Full Potential Linear Augmented Plane Wave (FLAPW) method within GGA+U approximation, are performed to investigate both electronic and magnetic properties of the GdS layers. Polarized spin and spin–orbit coupling are included in calculations within the framework of the antiferromagnetic state between two adjacent Gd layers. Magnetic moment considered to lie along (001) axes are computed. Obtained data from ab initio calculations are used as input for the High Temperature Series Expansions (HTSEs) calculations to compute other magnetic parameters. Using the Heisenberg model, the exchange interactions between the magnetic atoms Gd–Gd in the same layer and between the magnetic atoms in the adjacent bilayers are estimated. This estimate is obtained using the antiferromagnetic and ferromagnetic energies computed by abinitio calculations for GdS layers. The High Temperature Series Expansions (HTSEs) of the magnetic susceptibility of GdS with antiferromagnetic moment (m Gd ) is given up to sixth order series versus of (J 11 (Gd–Gd)/k B T). The Néel temperature T N is obtained by mean field theory and by HTSEs of the magnetic susceptibility series using the Padé approximant method. The critical exponent γ associated with the magnetic susceptibility is calculated for GdS layers. - Highlights: • Electronic and magnetic properties of GdS are investigated using the ab initio calculations. • Obtained data from abinitio calculations are used as input for HTSEs to compute other magnetic parameters. • Néel temperature and critical exponent are deduced using HTSE method

Analysis on the energetics, magnetism and electronic properties in a 45° ZnO grain boundary doped with Gd

KAUST Repository

Devi, Assa Aravindh Sasikala

2018-04-13

The structural stability and magnetic properties of a grain boundary (GB) formed by aligning two ZnO single crystals oriented at an angle of 45° is investigated by density functional theory, using generalized gradient approximation (GGA) and taking the U parameter into consideration for the 4f impurity states. We found that the GB is stable with no dangling bonds and inter-granular structures. The stability of defects such as Gd substituted to the Zn site (Gd), Zn vacancy (V) and O vacancy (V) as well as defect complexes Gd-Gd, Gd-V, and Gd-V are analyzed using formation energy calculations. It is found that Gd-Gd clusters prefers to form at the GB. The spin polarization at the Gd sites is too localized and the exchange coupling energy is insufficient to overcome the thermal fluctuations. However, we show that the presence of V increases the hybridization between p orbitals of O as well as d orbitals of Zn, which can assist in increasing the magnetic polarization of the system. This work advances the understanding of the ferromagnetism in Gd-doped ZnO, indicating that Gd clustering at the GB is not likely to contribute to the ferromagnetism.

Gadolinium released by the linear gadolinium-based contrast-agent Gd-DTPA decreases the activity of human epithelial Na+ channels (ENaCs).

Science.gov (United States)

Knoepp, Fenja; Bettmer, Joerg; Fronius, Martin

2017-05-01

Gadolinium-based-contrast-agents (GBCAs) are used for magnetic-resonance-imaging and associated with renal and cardiovascular adverse reactions caused by released Gd 3+ ions. Gd 3+ is also a modulator of mechano-gated ion channels, including the epithelial Na + channel (ENaC) that is expressed in kidney epithelium and the vasculature. ENaC is important for salt-/water homeostasis and blood pressure regulation and a likely target of released Gd 3+ from GBCAs causing the above-mentioned adverse reactions. Therefore this study examined the effect of Gd 3+ and GBCAs on ENaC's activity. Human αβγENaC was expressed in Xenopus laevis oocytes and exposed to Gd 3+ , linear (Gd-DTPA, Magnevist) or cyclic (Dotarem) GBCAs. Transmembrane ion-currents (I M ) were recorded by the two-electrode-voltage-clamp technique and Gd 3+ -release by Gd-DTPA was confirmed by inductively coupled plasma-mass spectrometry. Gd 3+ exerts biphasic effects on ENaC's activity: ≤0.3mmol/l decreased I M which was preventable by DEPC (modifies histidines). Strikingly Gd 3+ ≥0.4mmol/l increased I M and this effect was prevented by cysteine-modifying MTSEA. Linear Gd-DTPA and Magnevist mimicked the effect of ≤0.3mmol/l Gd 3+ , whereas the chelator DTPA showed no effect. Gd 3+ and Gd-DTPA increased the IC 50 for amiloride, but did not affect ENaC's self-inhibition. Interestingly, cyclic Gd-DOTA (Dotarem) increased I M to a similar extent as its chelator DOTA, suggesting that the chelator rather than released Gd 3+ is responsible for this effect. These results confirm Gd 3+ -release from linear Gd-DTPA and indicate that the released Gd 3+ amount is sufficient to interfere with ENaC's activity to provide putative explanations for GBCA-related adverse effects. Copyright © 2017 Elsevier B.V. All rights reserved.

Preparation and performance of intermediate-temperature fuel cells based on Gd-doped ceria electrolytes with different compositions

International Nuclear Information System (INIS)

Li, Zhimin; Mori, Toshiyuki; Yan, Pengfei; Wu, Yuanyuan; Li, ZhiPeng

2012-01-01

Highlights: ► Gd 0.1 Ce 0.9 O 1.95 electrolyte had less density of oxygen vacancies ordering. ► Gd 0.2 Ce 0.8 O 1.9 fuel cell showed better performance than Gd 0.1 Ce 0.9 O 1.95 . ► The relationship between microstructures and performance for cells were discussed. ► Gd 0.2 Ce 0.8 O 1.9 electrolyte with higher grain boundary conductivity was concluded. - Abstract: In this work, the effect of two frequently used Gd x Ce 1−x O 2−x/2 electrolytes (x = 0.1 and x = 0.2) on the performance of fuel cells operated at intermediate temperature was studied. The microstructures of ceria electrolytes responsible for the performance were discussed. Electrochemical measurements of as-prepared cells showed that the cell with Gd 0.2 Ce 0.8 O 1.9 electrolyte had a better performance than that of Gd 0.1 Ce 0.9 O 1.95 . It can be concluded that the increase of grain boundary conductivity of Gd 0.2 Ce 0.8 O 1.9 electrolyte contributes to its better cell performance.

Data of evolutionary structure change: 1RAAA-3GD5D [Confc[Archive

Lifescience Database Archive (English)

Full Text Available 1RAAA-3GD5D 1RAA 3GD5 A D ANPLYQKHIISINDLSRDDLNLVLATAAKLKANPQPELL...RDPFEAARGAHILYTDVWTHRLQLFEQYQINAAL-----------LNC--AAAEAIVLHCLPAHRGEEITDEVMEGPRSRI... 0 1RAA A 1RAAA...RAA A 1RAAA P...ine> 1RAA A 1RAAA

Optical flare observed in the flaring gamma-ray blazar Ton 599

Science.gov (United States)

Pursimo, Tapio; Sagues, Ana; Telting, John; Ojha, Roopesh

2017-11-01

We report optical photometry of the flat spectrum radio quasar Ton 599, obtained with the 2.56m Nordic Optical Telescope in La Palma, to look for any enhanced optical activity associated with a recent flare in the daily averaged gamma-ray flux (ATel#10931, ATel#10937).

2016 Billion-ton report: Advancing domestic resources for a thriving bioeconomy, Volume 1: Economic availability of feedstock

Science.gov (United States)

M.H. Langholtz; B.J. Stokes; L.M. Eaton

2016-01-01

This product builds on previous efforts, namely the 2005 Billion-Ton Study (BTS) and the 2011 U.S. Billion-Ton Update (BT2).With each report, greater perspective is gained on the potential of biomass resources to contribute to a national energy strategy. Similarly, each successive report introduces new questions regarding commercialization challenges. BTS quantified...

Synthesis and photoluminescence properties of GdBO3:Ln3+ (Ln = Eu, Tb) nanofibers by electrospinning

International Nuclear Information System (INIS)

Shen, Hongzhi; Feng, Shuo; Wang, Ying; Gu, Yipeng; Zhou, Jing; Yang, Hang; Feng, Guanlin; Li, Liang; Wang, Wenquan; Liu, Xiaoyang; Xu, Dapeng

2013-01-01

Highlights: ► GdBO 3 :Ln 3+ nanofibers were synthesized successfully by electrospinning. ► The samples have the average diameter of 150 nm and the flexible morphology. ► The GdBO 3 : Eu 3+ nanofibers have the stronger orange emission. ► The luminescence properties are different from the reported bulk material. ► We describe the energy transform process of GdBO 3 :Ln 3+ system. - Abstract: GdBO 3 :Ln 3+ (Ln = Eu, Tb) nanofibers were synthesized using electrospinning combined with heat treatment. The synthesized nanofibers were characterized by X-ray diffraction, Raman spectroscopy, field emission-scanning electron microscopy, thermogravimetric and differential thermal analyses, and photoluminescence. The experimental results show that the flexible synthesized nanofibers have an average diameter of approximately 150 nm. The nanofibers consist of crystalline grains with diameters of about 40 nm and have a vaterite-type structure of GdBO 3 . The GdBO 3 :Eu 3+ nanofibers exhibit strong orange and weak red emissions with a low ratio of red to orange emission intensities, which is different from those of the reported bulk materials and nanoparticles. The luminescence properties of the synthesized GdBO 3 :Tb 3+ nanofibers are essentially consistent with those of the synthesized GdBO 3 :Tb 3+ powders by solid-state reaction.

Studies on the Sintering Behaviour of UO2-Gd2O3 Nuclear Fuel

International Nuclear Information System (INIS)

Durazzo, Michelangelo; Gracher Riella, Humberto

2008-01-01

The incorporation of gadolinium directly into nuclear power reactor fuel is important from the point of reactivity compensation and adjustment of power distribution enabling thus longer fuel cycles and optimized fuel utilization. The incorporation of Gd 2 O 3 powder directly into the UO 2 powder by dry mechanical blending is the most attractive process because of its simplicity. Nevertheless, processing by this method leads to difficulties while obtaining sintered pellets with the minimum required density. This is due to blockages during the sintering process. There is little information in published literature about the possible mechanism for this blockage and this is restricted to the hypothesis based on formation of a low diffusivity Gd rich (U,Gd)O 2 phase. Experimental evidences indicated the existence of phases in the (U,Gd)O 2 system with structure different from the fluorite type structure of UO 2 . The apparition of these new phases coincides with the lowering of the density after sintering and with the lowering of the interdiffusion coefficient. However, it has been shown experimentally that the sintering blockage phenomena cannot be explained on the basis of the formation of low diffusivity Gd rich (U,Gd)O 2 phases. The work was continued to investigate other possible blocking mechanism. (authors)

Photon strength functions in Gd isotopes studied from radiative capture of resonance neutrons

Directory of Open Access Journals (Sweden)

Kroll J.

2014-04-01

Full Text Available The experimental spectra of γ rays following radiative neutron capture on isolated resonances of stable 152,154–158Gd targets were measured by the DANCE calorimeter installed at the Los Alamos Neutron Scattering Center in New Mexico, USA. These spectra were analyzed within the extreme statistical model to get new information on the photon strength functions. Special emphasis was put on study of the scissors vibrational mode present in these isotopes. Our data show that the scissors-mode resonances are built not only on the ground states but also on the excited levels of all studied Gd isotopes. The scissors mode strength observed in 157,159Gd products is significantly higher than in neighboring even-even nuclei 156,158Gd. Such a difference indicates the existence of an odd-even effect in the scissors mode strength. Moreover, there exists no universal parameter-free model of the electric dipole photon strength function describing the experimental data in all of the Gd isotopes studied. The results for the scissors mode are compared with the (γ, γ′ data for the ground-state transitions and with the results from 3He-induced reactions.

CHANGES IN SOIL CHEMICAL PROPERTIES OF ORGANIC PADDY FIELD WITH AZOLLA APPLICATION

Directory of Open Access Journals (Sweden)

Jauhari Syamsiyah

2016-12-01

Full Text Available The use of organic fertilizer is a way to improve soil fertility. Azolla can be used as organic fertilizer. This study aims to determine the effect of Azolla (Azolla mycrophylla. L on some soil chemical properties on organic paddy field. The field experiments used factorial complete randomized block design of three factors, namely Azolla (0 and 2 tons/ha, Manure (0 and 10 tons/ha and Rice Varieties (Mira1, Mentik Wangi and Merah Putih, with three times replication. Using Azolla on an organic paddy field does not significantly increase the levels of soil N, organic C, Cation Exchange Capacity and soil pH. However Azolla’s influence on soil available P is significant.

Stress-strain behavior under static loading in Gd123 high-temperature superconductors at 77 K

Science.gov (United States)

Fujimoto, Hiroyuki; Murakami, Akira; Teshima, Hidekazu; Morita, Mitsuru

2013-10-01

Mechanical properties of melt-growth GdBa2Cu3Ox (Gd123) superconducting samples with 10 wt.% Ag2O and 0.5 wt.% Pt were evaluated at 77 K through flexural tests for specimens cut from the samples in order to estimate the mechanical properties of the Gd123 material without metal substrates, buffer layers or stabilization layers. We discuss the mechanical properties; the Young's modulus and flexural strength with stress-strain behavior at 77 K. The results show that the flexural strength and fracture strain of Gd123 at 77 K are approximately 100 MPa and 0.1%, respectively, and that the origin of the fracture is defects such as pores, impurities and non-superconducting compounds. We also show that the Young's modulus of Gd123 is estimated to be 160-165 GPa.

Effects of Gd substitution on the structural and magnetic properties of strontium hexaferrites

Science.gov (United States)

Litsardakis, G.; Manolakis, I.; Serletis, C.; Efthimiadis, K. G.

2007-09-01

The effect of Gd substitution in M-type strontium hexaferrites has been examined in two series of samples, (Sr1-xGdx)O·5.25Fe2O3 and Sr1-xGdxFe12-xCoxO19, both prepared by the ceramic method, where x=0-0.40. The samples have been characterized by XRD, VSM and SEM-EDAX techniques. All substituted samples present primarily the hexaferrite structure. Sample (Sr0.95Gd)O·5.25Fe2O3 is single phase. Formation of impurity phases is affected by stoichiometry and presence of Co. In Sr-Gd samples, coercivity showed a maximum value of 305 kA/m (3.8 kOe) for x=0.20, while remanence and saturation magnetization did not decrease. Coercivity and magnetization in the Sr-Gd-Co series decreased steadily with substitution degree.

X-ray excited photoluminescence near the giant resonance in solid-solution Gd(1-x)Tb(x)OCl nanocrystals and their retention upon solvothermal topotactic transformation to Gd(1-x)Tb(x)F3.

Science.gov (United States)

Waetzig, Gregory R; Horrocks, Gregory A; Jude, Joshua W; Zuin, Lucia; Banerjee, Sarbajit

2016-01-14

Design rules for X-ray phosphors are much less established as compared to their optically stimulated counterparts owing to the absence of a detailed understanding of sensitization mechanisms, activation pathways and recombination channels upon high-energy excitation. Here, we demonstrate a pronounced modulation of the X-ray excited photoluminescence of Tb(3+) centers upon excitation in proximity to the giant resonance of the host Gd(3+) ions in solid-solution Gd1-xTbxOCl nanocrystals prepared by a non-hydrolytic cross-coupling method. The strong suppression of X-ray excited optical luminescence at the giant resonance suggests a change in mechanism from multiple exciton generation to single thermal exciton formation and Auger decay processes. The solid-solution Gd1-xTbxOCl nanocrystals are further topotactically transformed with retention of a nine-coordinated cation environment to solid-solution Gd1-xTbxF3 nanocrystals upon solvothermal treatment with XeF2. The metastable hexagonal phase of GdF3 can be stabilized at room temperature through this topotactic approach and is transformed subsequently to the orthorhombic phase. The fluoride nanocrystals indicate an analogous but blue-shifted modulation of the X-ray excited optical luminescence of the Tb(3+) centers upon X-ray excitation near the giant resonance of the host Gd(3+) ions.

Data of evolutionary structure change: 1RAAA-3GD5F [Confc[Archive

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Gd-DTPA-enhanced T{sub 1}-weighted excretory MR urography after low-dose diuretic injection; T{sub 1}-gewichtete MR-Ausscheidungsurographie mittels Gd-DTPA und vorheriger niedrigdosierter Gabe eines Diuretikums

Energy Technology Data Exchange (ETDEWEB)

Nolte-Ernsting, C.; Buecker, A.; Adam, G.; Neuerburg, J.; Guenther, R.W. [Universitaetsklinikum der RWTH Aachen (Germany). Klinik fuer Radiologische Diagnostik

1997-09-01

Purpose: Assessment of the morphology of the urinary tract by gadolinium(Gd)-enhanced T{sub 1}-weighted MR-urography (MRU) and precontrast diuretic injection. Methods: MRU was performed in 5 patients using Gd-DTPA-enhanced coronal T{sub 1}-weighted 3D-gradient-echo sequences with different spatial resolution. Prior to contrast injection, 10 mg of furosemide were administered intravenously. Results: Secondary to the precontrast furosemide injection, the increase of the renal excretion rate allows complete visualisation of the entire collecting system within 10 minutes following Gd injection. Maximum intensity projections provide a three-dimensional overview of the ureters separate from the bladder. To achieve detailed anatomic imaging of the calices, both optimal distension and high resolution sequences are prerequisites which cannot be realized by means of survey urograms only. (orig./AJ) [Deutsch] Ziel: Darstellung der Morphologie der ableitenden Harnwege mittels T{sub 1}-gewichteter MR-Urographie (MRU) nach Gabe eines nierengaengigen Gadolinium(Gd)-Chelates und vorheriger Diuretikumapplikation. Methoden: Der Harntrakt von 5 Patienten wurde nach Injektion von Gd-DTPA mit koronaren T{sub 1}-gewichteten 3D-Gradienten-Echo-Sequenzen unterschiedlicher Ortsaufloesung untersucht. Vor der Kontrastmittelgabe wurden jeweils 10 mg Furosemid intravenoes verabreicht. Ergebnisse: Nach initialer Steigerung des Harnflusses durch Furosemidgabe wurden Uebersichtsurogramme mit vollstaendig durchzeichnenden Ureteren bereits 10 min nach Gd-Injektion erzielt. Maximumintensitaetsprojektionen ermoeglichten die Beurteilung des dreidimensionalen Verlaufes der Ureteren ohne Blasenueberlagerung. Eine genauere anatomische Darstellung der Nierenkelche erforderte neben einem guten Fuellungszustand eine moeglichst hohe Sequenzaufloesung, die mit Uebersichtsurogrammen allein nicht zu erreichen war. (orig./AJ)

Hydrogen absorption in Ce{sub x}Gd{sub 1-x} alloys

Energy Technology Data Exchange (ETDEWEB)

Bereznitsky, M. [Department of Nuclear Engineering, Ben Gurion University of the Negev, P.O. Box 653, Beer Sheva 84105 (Israel); Bloch, J. [Nuclear Research Center-Negev, P.O. Box 9001, Beer Sheva 84190 (Israel); Yonovich, M. [Department of Nuclear Engineering, Ben Gurion University of the Negev, P.O. Box 653, Beer Sheva 84105 (Israel); Schweke, D. [Nuclear Research Center-Negev, P.O. Box 9001, Beer Sheva 84190 (Israel); Mintz, M.H. [Department of Nuclear Engineering, Ben Gurion University of the Negev, P.O. Box 653, Beer Sheva 84105 (Israel); Nuclear Research Center-Negev, P.O. Box 9001, Beer Sheva 84190 (Israel); Jacob, I., E-mail: izi@bgu.ac.il [Department of Nuclear Engineering, Ben Gurion University of the Negev, P.O. Box 653, Beer Sheva 84105 (Israel)

2012-08-15

Highlights: Black-Right-Pointing-Pointer Ce{sub x}Gd{sub 1-x} alloys exhibit the most negative heats of hydride formation ever found. Black-Right-Pointing-Pointer Thermodynamics of H absorption in Ce{sub x}Gd{sub 1-x} correlates with the alloys hardness. Black-Right-Pointing-Pointer The entropies of H solution and hydride formation reflect the hydrogen vibrations. Black-Right-Pointing-Pointer Terminal hydrogen solubilities change in a monotonic way between Ce and Gd. - Abstract: The effect of alloying on the thermodynamics of hydrogen absorption was studied for Ce{sub x}Gd{sub 1-x} alloys (0 {<=} x {<=} 1) at temperatures between 850 K and 1050 K in the 1-10{sup -4} Torr pressure range. The temperature-dependent hydrogen solubilities and plateau pressures for hydride formation were obtained from hydrogen absorption isotherms. The terminal hydrogen solubility (THS) at a given temperature changes in a monotonic way as a function of x. It is approximately three times higher in Gd, than in Ce, throughout the investigated temperature range. This monotonic behavior is opposed to that of many other substitutional alloys, for which the hydrogen terminal solubility increases with increasing solute concentrations. The enthalpies, {Delta}H{sub f}, and the entropies, {Delta}S{sub f}, of the dihydride formation exhibit a pronounced and broad negative minimum starting at x Almost-Equal-To 0.15, yielding the most negative {Delta}H{sub f} values ever found for metal hydrides. On the other hand, the enthalpies and entropies of ideal solution display a positive trend at x = 0.15 and x = 0.3. Both behaviors are considered in view of a reported distinct variation of the Ce{sub x}Gd{sub 1-x} hardness as a function of x. The particular compositional variations of the entropies of solution and formation as a function of x reflect most likely the vibrational properties of the hydrogen atoms in the metal matrices.

Theoretical Magnon Dispersion Curves for Gd

DEFF Research Database (Denmark)

Lindgård, Per-Anker; Harmon, B. N.; Freeman, A. J.

1975-01-01

The magnon dispersion curve of Gd metal has been determined from first principles by use of augmented-plane-wave energy bands and wave functions. The exchange matrix elements I(k⃗, k⃗′) between the 4f electrons and the conduction electrons from the first six energy bands were calculated under...

U.S. Billion-Ton Update: Biomass Supply for a Bioenergy and Bioproducts Industry

Energy Technology Data Exchange (ETDEWEB)

Downing, Mark [ORNL; Eaton, Laurence M [ORNL; Graham, Robin Lambert [ORNL; Langholtz, Matthew H [ORNL; Perlack, Robert D [ORNL; Turhollow Jr, Anthony F [ORNL; Stokes, Bryce [Navarro Research & Engineering; Brandt, Craig C [ORNL

2011-08-01

The report, Biomass as Feedstock for a Bioenergy and Bioproducts Industry: The Technical Feasibility of a Billion-Ton Annual Supply (generally referred to as the Billion-Ton Study or 2005 BTS), was an estimate of 'potential' biomass based on numerous assumptions about current and future inventory, production capacity, availability, and technology. The analysis was made to determine if conterminous U.S. agriculture and forestry resources had the capability to produce at least one billion dry tons of sustainable biomass annually to displace 30% or more of the nation's present petroleum consumption. An effort was made to use conservative estimates to assure confidence in having sufficient supply to reach the goal. The potential biomass was projected to be reasonably available around mid-century when large-scale biorefineries are likely to exist. The study emphasized primary sources of forest- and agriculture-derived biomass, such as logging residues, fuel treatment thinnings, crop residues, and perennially grown grasses and trees. These primary sources have the greatest potential to supply large, reliable, and sustainable quantities of biomass. While the primary sources were emphasized, estimates of secondary residue and tertiary waste resources of biomass were also provided. The original Billion-Ton Resource Assessment, published in 2005, was divided into two parts-forest-derived resources and agriculture-derived resources. The forest resources included residues produced during the harvesting of merchantable timber, forest residues, and small-diameter trees that could become available through initiatives to reduce fire hazards and improve forest health; forest residues from land conversion; fuelwood extracted from forests; residues generated at primary forest product processing mills; and urban wood wastes, municipal solid wastes (MSW), and construction and demolition (C&D) debris. For these forest resources, only residues, wastes, and small

Electronic and magnetic structures of GdS layers investigated by first principle and series expansions calculations

Energy Technology Data Exchange (ETDEWEB)

Masrour, R., E-mail: rachidmasrour@hotmail.com [Laboratory of Materials, Processes, Environment and Quality, Cady Ayyed University, National School of Applied Sciences, 63 46000 Safi (Morocco); LMPHE (URAC 12), Faculty of Science, Mohammed V-Agdal University, Rabat (Morocco); Hlil, E.K. [Institut Néel, CNRS et Université Joseph Fourier, BP 166, F-38042 Grenoble cedex 9 (France); Hamedoun, M. [Institute of Nanomaterials and Nanotechnologies, MAScIR, Rabat (Morocco); Benyoussef, A. [LMPHE (URAC 12), Faculty of Science, Mohammed V-Agdal University, Rabat (Morocco); Institute of Nanomaterials and Nanotechnologies, MAScIR, Rabat (Morocco); Hassan II Academy of Science and Technology, Rabat (Morocco)

2014-04-01

Self-consistent ab initio calculations, based on Density Functional Theory (DFT) approach and using Full Potential Linear Augmented Plane Wave (FLAPW) method within GGA+U approximation, are performed to investigate both electronic and magnetic properties of the GdS layers. Polarized spin and spin–orbit coupling are included in calculations within the framework of the antiferromagnetic state between two adjacent Gd layers. Magnetic moment considered to lie along (001) axes are computed. Obtained data from ab initio calculations are used as input for the High Temperature Series Expansions (HTSEs) calculations to compute other magnetic parameters. Using the Heisenberg model, the exchange interactions between the magnetic atoms Gd–Gd in the same layer and between the magnetic atoms in the adjacent bilayers are estimated. This estimate is obtained using the antiferromagnetic and ferromagnetic energies computed by abinitio calculations for GdS layers. The High Temperature Series Expansions (HTSEs) of the magnetic susceptibility of GdS with antiferromagnetic moment (m{sub Gd}) is given up to sixth order series versus of (J{sub 11}(Gd–Gd)/k{sub B}T). The Néel temperature T{sub N} is obtained by mean field theory and by HTSEs of the magnetic susceptibility series using the Padé approximant method. The critical exponent γ associated with the magnetic susceptibility is calculated for GdS layers. - Highlights: • Electronic and magnetic properties of GdS are investigated using the ab initio calculations. • Obtained data from abinitio calculations are used as input for HTSEs to compute other magnetic parameters. • Néel temperature and critical exponent are deduced using HTSE method.

Coupling fast water exchange to slow molecular tumbling in Gd3+ chelates: why faster is not always better.

Science.gov (United States)

Avedano, Stefano; Botta, Mauro; Haigh, Julian S; Longo, Dario L; Woods, Mark

2013-08-05

The influence of dynamics on solution state structure is a widely overlooked consideration in chemistry. Variations in Gd(3+) chelate hydration with changing coordination geometry and dissociative water exchange kinetics substantially impact the effectiveness (or relaxivity) of monohydrated Gd(3+) chelates as T1-shortening contrast agents for MRI. Theory shows that relaxivity is highly dependent upon the Gd(3+)-water proton distance (rGdH), and yet this distance is almost never considered as a variable in assessing the relaxivity of a Gd(3+) chelate as a potential contrast agent. The consequence of this omission can be seen when considering the relaxivity of isomeric Gd(3+) chelates that exhibit different dissociative water exchange kinetics. The results described herein show that the relaxivity of a chelate with "optimal" dissociative water exchange kinetics is actually lower than that of an isomeric chelate with "suboptimal" dissociative water exchange. When the rate of molecular tumbling of these chelates is slowed, an approach that has long been understood to increase relaxivity, the observed difference in relaxivity is increased with the more rapidly exchanging ("optimal") chelate exhibiting lower relaxivity than the "suboptimally" exchanging isomer. The difference between the chelates arises from a non-field-dependent parameter: either the hydration number (q) or rGdH. For solution state Gd(3+) chelates, changes in the values of q and rGdH are indistinguishable. These parametric expressions simply describe the hydration state of the chelate--i.e., the number and position of closely associating water molecules. The hydration state (q/rGdH(6)) of a chelate is intrinsically linked to its dissociative water exchange rate kex, and the interrelation of these parameters must be considered when examining the relaxivity of Gd(3+) chelates. The data presented herein indicate that the changes in the hydration parameter (q/rGdH(6)) associated with changing dissociative

Gadolinium scandium germanide, Gd2Sc3Ge4

Directory of Open Access Journals (Sweden)

Sumohan Misra

2009-04-01

Full Text Available Gd2Sc3Ge4 adopts the orthorhombic Pu5Rh4-type structure. The crystal structure contains six sites in the asymmetric unit: two sites are statistically occupied by rare-earth atoms with Gd:Sc ratios of 0.967 (4:0.033 (4 and 0.031 (3:0.969 (3, one site (.m. symmetry is occupied by Sc atoms, and three distinct sites (two of which with .m. symmetry are occupied by Ge atoms. The rare-earth atoms form two-dimensional slabs with Ge atoms occupying the trigonal-prismatic voids.

The Gd14Ag51 structure type and its relation to some complex amalgam structures

International Nuclear Information System (INIS)

Tambornino, Frank; Sappl, Jonathan; Hoch, Constantin

2015-01-01

Highlights: • The Gd 14 Ag 51 structure type has been revisited on the basis of single crystal diffraction data. • Symmetry analysis from electron density and TEM shows the space group P6/m to be true. • Gd 14 Ag 51 shows good metallic behaviour. • Structure relations to alkali, alkaline-earth and rare-earth metal amalgams can be established. • Complexity values for the RE 14 Ag 51 structure family were calculated. - Abstract: A plethora of binary and ternary intermetallic compounds has been assigned to the Gd 14 Ag 51 structure type, crystallising in the hexagonal system (space group P6/m, a = 1264.30(18) pm, c = 933.58(11) pm for Gd 14 Ag 51 ). Starting in the late 1960s, much work has been invested in the structural elucidation of these crystal structures. However, reliable single crystal data are scarce, and most structure type assignments have been performed merely on the basis of powder data. We have redetermined four representatives of the binary RE 14 Ag 51 structure type (RE = Y, Ce, Gd, Tb) with modern high-precision single crystal X-ray methods. The assignment of the Gd 14 Ag 51 structure type to space group P6/m was additionally verified by careful analysis of high resolution transmission electron micrographs. We emphasise the close relation of the Gd 14 Ag 51 structure type to the structures of some recently described amalgams of similar composition focussing on disorder phenomena and structural complexity. Furthermore, we provide detailed information on synthesis as well as electrical and magnetic properties for Gd 14 Ag 51 , the parent compound of this structure family

Doping effects on the structural, magnetic, and hyperfine properties of Gd-doped SnO{sub 2} nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Coelho-Júnior, H.; Aquino, J. C. R.; Aragón, F. H. [Universidade de Brasília, Núcleo de Física Aplicada, Instituto de Física (Brazil); Hidalgo, P. [Universidade de Brasília, Faculdade Gama-FGA, Setor Central Gama (Brazil); Cohen, R.; Nagamine, L. C. C. M. [Universidade de São Paulo, Instituto de Física (Brazil); Coaquira, J. A. H., E-mail: coaquira@unb.br; Silva, S. W. da [Universidade de Brasília, Núcleo de Física Aplicada, Instituto de Física (Brazil); Brito, H. F. [Universidade de São Paulo, Instituto de Química (Brazil)

2014-12-15

In this work we present the study of the structural, magnetic, and hyperfine properties of Gd-doped SnO{sub 2} nanoparticles synthesized by a polymer precursor method. The X-ray diffraction data analysis shows the formation of the rutile-type structure in all samples with Gd content from 1.0 to 10.0 mol%. The mean crystallite size is ∼11 nm for the 1.0 mol% Gd-doped samples and it shows a decreasing tendency as the Gd content is increased. The analysis of magnetic measurements indicates the coexistence of ferromagnetic and paramagnetic phases for the 1.0 mol% Gd-doped sample; however, above that content, only a paramagnetic phase is observed. The ferromagnetic phase observed in the 1.0 mol% Gd-doped sample has been assigned to the presence of bound magnetic polarons which overlap to create a spin-split impurity band. Room-temperature {sup 119}Sn Mössbauer measurements reveal the occurrence of strong electric quadrupole interactions. It has been determined that the absence of magnetic interactions even for 1.0 mol% Gd-doped sample has been related to the weak magnetic field associated to the exchange interaction between magnetic ions and the donor impurity band. The broad distribution of electric quadrupole interactions are attributed to the several non-equivalent surroundings of Sn{sup 4+} ions provoked by the entrance of Gd{sup 3+} ions and to the likely presence of Sn{sup 2+} ions. The isomer shift seems to be nearly independent of the Gd content for samples with Gd content below 7.5 mol%.

High temperature X-ray diffraction studies on HfO2-Gd2O3 system

International Nuclear Information System (INIS)

Panneerselvam, G.; Antony, M.P.; Ananthasivan, K.; Joseph, M.

2016-01-01

High temperature X-ray diffraction (HTXRD) technique is an important experimental tool for measuring thermal expansion of materials of interest. A series of solid solutions containing GdO 1.5 in HfO 2 ,Hf 1-y Gd y )O 2 (y = 0.15, 0.2, 0.3, 0.41 and 0.505) were prepared by solid state method. Structural characterization and computation of lattice parameter was carried out by using room temperature X-ray diffraction measurements. The room temperature lattice parameter estimated for (Hf 1-y Gd y )O 2 (y=0.15, 0.2, 0.3, 0.41 and 0.505) are 0.51714 nm, 0.51929 nm, 0.52359nm, 0.52789nm and 0.53241 nm, respectively. Thermal expansion coefficients and percentage linear thermal expansion of the HfO 2 -Gd 2 O 3 solid solutions containing 20 and 41 mol% GdO 1.5 were determined using HTXRD in the temperature range 298 to 1673K. The mean linear thermal expansion coefficients of the solid solutions containing 20 and 41 mol. %Gd are 11.65 x 10 -6 K -1 and 12.07 x 10 -6 K -1 , respectively. (author)

Magnetic and crystallographic properties of Gd(Cu/sub 1-x/Ni/sub x/)2 and Gd(Cu/sub 1-x/Al/sub x/)2 intermetallic compounds

International Nuclear Information System (INIS)

Borombaev, M.K.; Levitin, R.Z.; Markosyan, A.S.; Snegirev, V.V.

1986-01-01

Magnetization, paramagnetic susceptibility, and temperature dependence of lattice parameters of Gd(Cu/sub 1-x/Ni/sub x/) 2 (0 2 (0 2 -type structure have been studied in a wide range of temperatures. Below the ordering temperature anomalies in thermal expansion along the crystallographic axes a, b, and c enabled to distinguish between various types of magnetic arrangements. The Gd(Cu/sub 1-x/Ni/sub x/) 2 system has two types of antiferromagnetic phases: AF1 (0 = 0.13 the system orders ferromagnetically. In the Gd(Cu/sub 1-x/Al/sub x/) 2 system two magnetic phases AF1 and AF3 occur in the concentration regions 0 <= x <= 0.035 and 0.04 <= x <= 0.07, respectively. The obtained results are discussed in terms of the RKKY model via the changing conduction electron concentration. (author)

Structural, magnetic, and electrical properties of Gd-doped BiFeO3 nanoparticles with reduced particle size

International Nuclear Information System (INIS)

Lotey, Gurmeet Singh; Verma, N. K.

2012-01-01

Pure and Gd-doped BiFeO 3 nanoparticles have been synthesized by sol–gel method. The significant effects of size and Gd-doping on structural, electrical, and magnetic properties have been investigated. X-ray diffraction study reveals that the pure BiFeO 3 nanoparticles possess rhombohedral structure, but with 10% Gd-doping complete structural transformation from rhombohedral to orthorhombic has been observed. The particle size of pure and Gd-doped BiFeO 3 nanoparticles, calculated using Transmission electron microscopy, has been found to be in the range 25–15 nm. Pure and Gd-doped BiFeO 3 nanoparticles show ferromagnetic character, and the magnetization increases with decrease in particle size and increase in doping concentration. Scanning electron microscopy study reveals that grain size decreases with increase in Gd concentration. Well-saturated polarization versus electric field loop is observed for the doped samples. Leakage current density decreases by four orders by doping Gd in BiFeO 3 . The incorporation of Gd in BiFeO 3 enhances spin as well as electric polarization at room temperature. The possible origin of enhancement in these properties has been explained on the basis of dopant and its concentration, phase purity, small particle, and grain size.

Synthesis and Characterization of Gd2O3 Hollow Microspheres Using a Template-Directed Method

Directory of Open Access Journals (Sweden)

Xueliang Jiang

2016-04-01

Full Text Available Uniform rare-earth gadolinium oxide (Gd2O3 hollow microspheres, as formed through a urea-assisted homogenous precipitation process using carbon spheres as a template and a subsequent heat treatment, were characterized by using X-ray diffraction, Fourier transformed infared spectroscopy, thermogravimetry, X-ray photoelectron spectroscopy, scanning electron microscopy, transmission electron microscopy and Brunauer-Emmett-Tellet surface area measurement. The results indicate that the final products can be indexed to a cubic Gd2O3 phase with high purity and have a uniform morphology at 500 nm in diameter and 20 nm in shell thickness. The as-synthesized Gd2O3 hollow microspheres exhibited a superior photooxidation activity to that of Gd2O3 powder and an effect similar to P25, significantly broadening the potential of Gd2O3 hollow microspheres for many practical applications.

46 CFR 25.25-17 - Survival craft requirements for uninspected passenger vessels of at least 100 gross tons.

Science.gov (United States)

2010-10-01

... 46 Shipping 1 2010-10-01 2010-10-01 false Survival craft requirements for uninspected passenger... Survival craft requirements for uninspected passenger vessels of at least 100 gross tons. (a) Each uninspected passenger vessel of at least 100 gross tons must have adequate survival craft with enough capacity...

Transcription of gD and gI genes in BHV1-infected cells

Indian Academy of Sciences (India)

) are contiguous genes with 141 bp region between the two open reading frames (ORFs). Expression of gD and gI from a bicistronic construct containing complete gD and gI gene has been reported either through internal ribosome entry site ...

Inter-atomic bonding and dielectric polarization in Gd"3"+ incorporated Co-Zn ferrite nanoparticles

International Nuclear Information System (INIS)

Pawar, R.A.; Desai, S.S.; Patange, S.M.; Jadhav, S.S.; Jadhav, K.M.

2017-01-01

A series of ferrite with a chemical composition Co_0_._7Zn_0_._3Gd_xFe_2_−_xO_4 (where x=0.0 to x=0.1) were prepared by sol-gel auto-combustion method. X-ray diffraction pattern were used to determine the crystal structure and phase formation of the prepared samples. Scanning electron microscopy is used to study the surface morphology of the prepared samples. Elastic properties were determined from the infrared spectroscopy. Debye temperature, wave velocities, elastic constants found to increase with the increase in Gd"3"+ substitution. Dielectric properties such as dielectric constant and dielectric loss were studied as a function of Gd"3"+ substitution and frequency. Dielectric constant decreased with the increase in frequency and Gd"3"+ substitution. Behavior of dielectric properties was explained on the basis of Maxwell-Wagner interfacial polarization which in accordance with Koops phenomenological theory. Real and imaginary part of impedance was studied as a function of resistance and Gd"3"+ substitution. The behavior of impedance is systematically discussed on the basis of resistance-capacitance circuit.

Turning Maneuver Limitations Imposed by Sudden Strut Side Ventilation on a 200-Ton 80-Knot Hydrofoil Craft

Science.gov (United States)

1975-05-01

ventilated, but never supercavitating , for speeds up to 80 knots. In particular, choking of the air flow to the foil vent was not con- sidered. If this...4Conolly, A.C., "Experimental Investigations of Supercavitating Hydrofoils with Flaps," General Dynamics/Convair Report GD/C-63-210 (Dec 1963). 10 THE SIX...Dec 1966). 4. Conolly, A.C., "Experimenta, Investigations of Supercavitating Hydro- foils with Flaps," General Dynamics/Convair Report GD/C-63-210 (Dec

Superconducting Dy1-x(Gd,Yb)xBa2Cu3O7-δ thin films made by Chemical Solution Deposition

DEFF Research Database (Denmark)

Opata, Yuri Aparecido; Wulff, Anders Christian; Hansen, Jørn Otto Bindslev

2016-01-01

Dy1-x(Gd or Yb)xBa2Cu3O7-δ samples were prepared using chemical solution deposition (CSD), based on trifluoroacetate metal-organic decomposition (MOD) methods. X-ray diffraction results demonstrated the formation of the RE123 superconducting phase with a strong in-plane and out-of-plane texture. c...

Multipole mixing ratios in /sup 154/Gd

Energy Technology Data Exchange (ETDEWEB)

Chung, Won Mo; Song, Choong Sik; Joo, Koan Sik

1985-06-01

We have measured gamma-gamma angular correlations to determine the mixing ratios of several gamma transitions in /sup 154/Gd. The results are compared with those derived from the pairing-plus-quadrupole model and from the interacting boson model.

Synthesis and characterization of Al-TON zeolite using a dialkylimizadolium as structure-directing agent

Energy Technology Data Exchange (ETDEWEB)

Lopes, Christian Wittee; Pergher, Sibele Berenice Castella, E-mail: chriswittee@gmail.com [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil); Villarroel-Rocha, Jhonny [Laboratorio de Solidos Porosos, Instituto de Fisica Aplicada, Universidad Nacional de San Luis, Chacabuco, San Luis (Argentina); Silva, Bernardo Araldi Da; Mignoni, Marcelo Luis [Universidade Regional Integrada, Erechim, RS (Brazil)

2016-11-15

In this work, the synthesis of zeolites using 1-butyl-3-methylimidazolium chloride [C{sub 4}MI]Cl as a structure-directing agent was investigated. The organic cation shows effectiveness and selectivity for the syntheses of TON zeolites under different reaction conditions compared to the traditional structure directing agent, 1,8-diaminooctane. The 1-butyl-3-methylimidazolium cation lead to highly crystalline materials and its role as OSDA in our synthesis conditions has been confirmed by characterization techniques. ICP-OES confirms the presence of Al in the samples and {sup 27}Al MAS NMR analysis indicated that aluminum atoms were incorporated in tetrahedral coordination. Scanning electron microscopy indicated that changing the crystallization condition (static or stirring), zeolites with different crystal size were obtained, which consequently affects the textural properties of the zeolites. Moreover, varying some synthesis parameters MFI zeolite can also be obtained. (author)

TNF-α promotes nuclear enrichment of the transcription factor TonEBP/NFAT5 to selectively control inflammatory but not osmoregulatory responses in nucleus pulposus cells.

Science.gov (United States)

Johnson, Zariel I; Doolittle, Alexandra C; Snuggs, Joseph W; Shapiro, Irving M; Le Maitre, Christine L; Risbud, Makarand V

2017-10-20

Intervertebral disc degeneration (IDD) causes chronic back pain and is linked to production of proinflammatory molecules by nucleus pulposus (NP) and other disc cells. Activation of tonicity-responsive enhancer-binding protein (TonEBP)/NFAT5 by non-osmotic stimuli, including proinflammatory molecules, occurs in cells involved in immune response. However, whether inflammatory stimuli activate TonEBP in NP cells and whether TonEBP controls inflammation during IDD is unknown. We show that TNF-α, but not IL-1β or LPS, promoted nuclear enrichment of TonEBP protein. However, TNF-α-mediated activation of TonEBP did not cause induction of osmoregulatory genes. RNA sequencing showed that 8.5% of TNF-α transcriptional responses were TonEBP-dependent and identified genes regulated by both TNF-α and TonEBP. These genes were over-enriched in pathways and diseases related to inflammatory response and inhibition of matrix metalloproteases. Based on RNA-sequencing results, we further investigated regulation of novel TonEBP targets CXCL1 , CXCL2 , and CXCL3 TonEBP acted synergistically with TNF-α and LPS to induce CXCL1 -proximal promoter activity. Interestingly, this regulation required a highly conserved NF-κB-binding site but not a predicted TonE, suggesting cross-talk between these two members of the Rel family. Finally, analysis of human NP tissue showed that TonEBP expression correlated with canonical osmoregulatory targets TauT/SLC6A6 , SMIT/SLC5A3 , and AR/AKR1B1 , supporting in vitro findings that the inflammatory milieu during IDD does not interfere with TonEBP osmoregulation. In summary, whereas TonEBP participates in the proinflammatory response to TNF-α, therapeutic strategies targeting this transcription factor for treatment of disc disease must spare osmoprotective, prosurvival, and matrix homeostatic activities. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

Complexes of 4-chlorophenoxyacetates of Nd(III), Gd(III) and Ho(III)

International Nuclear Information System (INIS)

Ferenc, W.; Bernat, M; Gluchowska, H.W.; Sarzynski, J.

2010-01-01

The complexes of 4-chlorophenoxyacetates of Nd(III), Gd(III) and Ho(III) have been synthesized as polycrystalline hydrated solids, and characterized by elemental analysis, spectroscopy, magnetic studies and also by X-ray diffraction and thermogravimetric measurements. The analysed complexes have the following colours: violet for Nd(III), white for Gd(III) and cream for Ho(III) compounds. The carboxylate groups bind as bidentate chelating (Ho) or bridging ligands (Nd, Gd). On heating to 1173K in air the complexes decompose in several steps. At first, they dehydrate in one step to form anhydrous salts, that next decompose to the oxides of respective metals. The gaseous products of their thermal decomposition in nitrogen were also determined and the magnetic susceptibilities were measured over the temperature range of 76-303K and the magnetic moments were calculated. The results show that 4-chlorophenoxyacetates of Nd(III), Gd(III) and Ho(III) are high-spin complexes with weak ligand fields. The solubility value in water at 293K for analysed 4-chlorophenoxyacetates is in the order of 10 -4 mol/dm 3 . (author)

Correlation between structural, electrical and magnetic properties of GdMnO3 bulk ceramics

International Nuclear Information System (INIS)

Samantaray, S.; Mishra, D.K.; Pradhan, S.K.; Mishra, P.; Sekhar, B.R.; Behera, Debdhyan; Rout, P.P.; Das, S.K.; Sahu, D.R.; Roul, B.K.

2013-01-01

This paper reports the effect of sintering temperature on ferroelectric properties of GdMnO 3 (GMO) bulk ceramics at room temperature prepared by the conventional solid state reaction route following slow step sintering schedule. Ferroelectric hysteresis loop as well as sharp dielectric anomaly in pure (99.999%) GMO sintered ceramics has been clearly observed. Samples sintered at 1350 °C become orthorhombic with Pbnm space group and showed frequency independent sharp dielectric anomalies at 373 K and a square type of novel ferroelectric hysteresis loop was observed at room temperature. Interestingly, dielectric anomalies and ferroelectric behavior were observed to be dependent upon sintering temperature of GdMnO 3 . Room temperature dielectric constant (ε r ) value at different frequencies is observed to be abnormally high. The magnetic field and temperature dependent magnetization show antiferromagnetic behavior at 40 K for both 1350 °C and 1700 °C sintered GMO. Present findings showed the possibility of application of GdMnO 3 at room temperature as multifunctional materials. - Highlights: • Preparation of single-phasic polycrystalline GdMnO 3 sample by the solid state sintering route. • Observation of square type P–E hysteresis loop with higher saturation and remnant polarization. • Observation of antiferromagnetic behavior at 40 K in polycrystalline GdMnO 3 . • Possibility of room temperature application of GdMnO 3 as multifunctional material

Recent developments in melt processed Gd-123 and MgB{sub 2} materials at RTRI

Energy Technology Data Exchange (ETDEWEB)

Muralidhar, M., E-mail: miryala1@rtri.or.jp [Railway Technology Research Institute (RTRI), Applied Superconductivity, Materials Technology Division, 2-8-38 Hikari-cho, Kokubunji-shi, Tokyo 185-8540 (Japan); Fukumoto, Y.; Ishihara, A.; Suzuki, K.; Tomita, M. [Railway Technology Research Institute (RTRI), Applied Superconductivity, Materials Technology Division, 2-8-38 Hikari-cho, Kokubunji-shi, Tokyo 185-8540 (Japan); Koblischka, M.R. [Institute of Experimental Physics, Saarland University, P.O. Box 151150, D-66041 Saarbrucken (Germany); Yamamoto, A.; Kishio, K. [Department of Applied Chemistry, Faculty of Engineering, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-656 (Japan)

2014-01-15

Highlights: •Large size Gd-123 bulk material grown in air, using novel thin film Nd-123 seeds grown on MgO crystals. •Quality and uniformity of the Gd-123 materials are excellent. •Batch processed Gd-123 material was used for construction of chilled Maglev vehicle. •MgB{sub 2} bulks can be utilized around 20 K similarly to the Gd-123 material at 77 K. -- Abstract: In this contribution we will report on the current status, recent developments in GdBa{sub 2}Cu{sub 3}O{sub y} “Gd-123” and MgB{sub 2} material processing, characterization, and applications at the Railway Technical Research Institute (RTRI). Batch-processing of Gd-123 bulk material grown in air was performed using novel thin film Nd-123 seeds grown on MgO crystals. In this way, we are able to fabricate materials with good quality, and uniform performance. We examined the technology of the uniform performance of the large 45 mm diameter, single grain Gd-123 bulks for use in application of NMR. For this purpose, four 5 mm thick pieces are cut vertically from a single grain Gd-123 material and the magnetic field distribution is measured using a scanning hall sensor. We found that all four pieces are single domain and exhibit a quite uniform field distribution. Furthermore, the batch-processed bulk materials are used for the construction of a chilled Maglev vehicle. On the other hand, to optimize the trapped field performance of bulk MgB{sub 2} material, several samples were prepared by solid state reaction at different temperatures ranging from 750 to 950 °C in pure argon atmosphere. X-ray diffraction results indicated that single phase and homogenous MgB{sub 2} bulks are produced when sintering them around 775 °C. Further, atomic force microscopy (AFM) and scanning electron microscopy (SEM) indicated that an uniform grain size results by controlling the processing temperature. So, higher trapped fields can be achieved in sintered MgB{sub 2} material.

Structural evolution and electrical properties of BaTiO{sub 3} doped with Gd{sup 3+}

Energy Technology Data Exchange (ETDEWEB)

Hernandez Lara, Juan Pablo; Perez Labra, Miguel; Barrientos Hernandez, Francisco Raul, E-mail: miguelabra@hotmail.com [Autonomous University of Hidalgo (Mexico); Romero Serrano, Jose Antonio; Hernandez Ramirez, Aurelio [Metallurgy and Materials Department, ESIQIE-IPN, UPALM, Zacatenco (Mexico); Avila Davila, Erika Osiris [Mechanical Engineering Department, Technological Institute of Pachuca, Hidalgo (Mexico); Thangarasu, Pandiyan [Facultad de Quimica, UNAM, Mexico D.F. (Mexico)

2017-03-15

BaTiO{sub 3} doped with Gd{sup 3+} (Ba{sub 1-x}Gd{sub x}Ti{sub 1-x/4}O{sub 3}) was synthesized using the solid-state reaction method with x = 0.001, 0.003, 0.005, 0.01, 0.05, 0.1, 0.15, 0.20, 0.25, 0.30, and 0.35 Gd{sup 3+} (wt. %). The powders were decarbonated at 900 °C and sintered at 1400 °C for 8 hours. The tetragonality of the synthesized Gd{sup 3+}-doped BaTiO{sub 3} particles was analyzed. XRD patterns and Raman spectra revealed that the crystal phase of the obtained particles was predominately tetragonal BaTiO{sub 3}; the intensity of the Raman bands at 205 cm{sup -1}, 265 cm{sup -1}, and 304 cm{sup -1} decreased when Gd'3{sup +} was increased. A secondary phase (Gd{sub 2}Ti{sub 2}O{sub 7}) was found when the Gd{sup 3+} content was higher than 0.15 wt. %. The capacitance of the sintering pellets was measured at 1 kHz; these values were used to calculate the relative permittivity, the maximum permittivity values were recorded for the samples with x = 0.001, 0.005, and 0.1. (author)

An i{sub 13/2} neutron intruder band in {sup 141}Gd

Energy Technology Data Exchange (ETDEWEB)

Mullins, S M; Omar, A; Persson, L; Prevost, D; Waddington, J C [McMaster Univ., Hamilton, ON (Canada); Andrews, H R; Ball, G C; Galindo-Uribarri, A; Janzen, V P; Radford, D C; Ward, D [Atomic Energy of Canada Ltd., Chalk River, ON (Canada). Chalk River Nuclear Labs.; Drake, T E [Toronto Univ., ON (Canada). Dept. of Physics; Fossan, D B; Lafosse, D; Vaska, P; Waring, M [State Univ. of New York, Stony Brook, NY (United States). Dept. of Physics; Wadsworth, R [York Univ. (United Kingdom). Dept. of Physics

1992-08-01

The nucleus {sup 141}Gd has been investigated at high spins for the first time following the reactions {sup 112}Sn({sup 32}S,2pn){sup 141}Gd at 155 MeV and {sup 112}Sn({sup 33}S,2p2n){sup 141}Gd at 170 MeV. The methods of in-beam {gamma}-ray spectroscopy were used to establish a number of different structures, including a band which has been assigned as being based on the {nu}i{sub 13/2}[660]1/2{sup +} Nilsson intruder orbital. This is the heaviest nucleus thus far in which this type of intruder band has been identified. (author). 11 refs., 3 figs.

Pr and Gd co-doped bismuth ferrite thin films with enhanced

Indian Academy of Sciences (India)

Pr and Gd co-modified Bi0.95−PrGd0.05FeO3 ( = 0.00, 0.05, 0.10) (BPGFO) thin films on Pt(111)/Ti/SiO2/Si(100) substrates were prepared by a sol-gel together with spin coating technique. A detailed study of electrical and magnetic properties of these thin films is reported. X-ray diffraction analysis shows that, with an ...

Enhanced critical currents in (Gd,Y)Ba2Cu3Ox superconducting tapes with high levels of Zr addition

Energy Technology Data Exchange (ETDEWEB)

Selvamanickam, V; Chen, Y; Shi, T; Liu, Y; Khatri, ND; Liu, J; Yao, Y; Xiong, X; Lei, C; Soloveichik, S; Galstyan, E; Majkic, G

2013-01-21

The critical current and structural properties of (Gd,Y)BaCuO tapes made by metal organic chemical vapor deposition (MOCVD) with Zr addition levels up to 30 at.% have been investigated. The reduction in critical current beyond the previously optimized Zr addition level of 7.5 at.% was found to be due to structural deterioration of the (Gd,Y)Ba2Cu3Ox film. By a modified MOCVD process,enhanced critical current densities have been achieved with high levels of Zr addition,including 3.83 MA cm(-2) in 15 at.% Zr- added 1.1 mu m thick film at 77 K in zero magnetic field. Critical currents as high as 1072 A/ 12 mm have been reached in (Gd,Y) BaCuO tapes with 15 at.% Zr addition at 30 K in a field of 3 T applied perpendicular to the tape,corresponding to a pinning force value of 268 GN m(-3). The enhanced critical currents achievable with a high density of nanoscale defects by employing high levels of second- phase additions enable the performance targets needed for the use of HTS tapes in coil applications involving high magnetic fields at temperatures below 50 K to be met.

Enhanced critical currents in (Gd,Y)Ba2Cu3Ox superconducting tapes with high levels of Zr addition

International Nuclear Information System (INIS)

Selvamanickam, V; Shi, T; Liu, Y; Khatri, N D; Liu, J; Yao, Y; Galstyan, E; Majkic, G; Chen, Y; Xiong, X; Lei, C; Soloveichik, S

2013-01-01

The critical current and structural properties of (Gd,Y)BaCuO tapes made by metal organic chemical vapor deposition (MOCVD) with Zr addition levels up to 30 at.% have been investigated. The reduction in critical current beyond the previously optimized Zr addition level of 7.5 at.% was found to be due to structural deterioration of the (Gd,Y)Ba 2 Cu 3 O x film. By a modified MOCVD process, enhanced critical current densities have been achieved with high levels of Zr addition, including 3.83 MA cm −2 in 15 at.% Zr-added 1.1 μm thick film at 77 K in zero magnetic field. Critical currents as high as 1072 A/12 mm have been reached in (Gd,Y)BaCuO tapes with 15 at.% Zr addition at 30 K in a field of 3 T applied perpendicular to the tape, corresponding to a pinning force value of 268 GN m −3 . The enhanced critical currents achievable with a high density of nanoscale defects by employing high levels of second-phase additions enable the performance targets needed for the use of HTS tapes in coil applications involving high magnetic fields at temperatures below 50 K to be met. (paper)

Thermal expansion studies on HfO2-Gd2O3 system

International Nuclear Information System (INIS)

Panneerselvam, G.; Antony, M.P.; Nagarajan, K.

2014-01-01

A series of solid solutions containing GdO 1.5 in HfO 2 , (Hf 1-y Gd y ) O 2 (y = 0.15, 0.2, 0.3, 0.41 and 0.505) were prepared by solid state method. Structural characterization and computation of lattice parameter was carried out using room temperature X-ray diffraction measurements

MR imaging of acute myocardial infarction in pigs using Gd-DTPA-labeled dextran

International Nuclear Information System (INIS)

Wikstroem, M.; Martinussen, H.J.; Wikstroem, G.; Ericsson, A.; Nyman, R.; Waldenstroem, A.; Hemmingsson, A.

1992-01-01

Myocardial infarctions were induced in 12 pigs. In 6 pigs, dextran-(Gd-DTPA)15 (≅ 0.1 mmol Gd/kg b.w.) was injected i.v. 4 to 4.5 hours after coronary artery occlusion. ECG gated MR images were obtained repeatedly before (n=4) and after (n=6) contrast medium injection. Relaxation times in blood samples were measured repeatedly. The animals were scarificed 2 hours after contrast medium administration. The hearts were excised, reaxamined in the MR equipment and stained with triphenyltetrazolium chloride (TTC) in order to define areas of infarction. The remaining 6 pigs were sacrificed 6 hours after occlusion without administration of contrast medium. These hearts were only imaged ex vivo. In vivo, the infarctions could not be identified with or without dextran-(Gd-DTPA)15. Ex vivo, without contrast medium, the infarctions had an increased signal intensity, most pronounced in the T2-weighted images. Dextran-(Gd-DTPA)15 caused a prolonged, pronounced shortening of T1 und T2 in blood samples. The infarct demarcation improved in the T1-weighted images after injection of dextran-(Gd-DTPA)15, due to a moderate enhancement in normal myocardium and a stronger enhancement at the periphery of the infarctions, while the central parts of the infarctions were only weakly enhanced. (orig.)

Gamma multi-detectors and nuclear structure studies: search for superdeformed structures in {sup 147}Gd and {sup 144}Gd isotopes using Crystal Castle; simulation calculations for EUROGAM multi-detector definition; Multidetecteurs gamma et etudes de structure nucleaire: recherche avec le Chateau de Cristal de structures superdeformees dans les isotopes {sup 147}Gd et {sup 144}Gd; calculs de simulation pour la definition du multidetecteur EUROGAM

Energy Technology Data Exchange (ETDEWEB)

France, G de

1992-12-31

Computer simulations have been used for the calculation of the new generation of 4 {pi}{gamma} multi-detectors (Castle Crystal) of EUROGAM system (phase I and II). Two superdeformed bands (I and II), comprising 16 and 13 transitions respectively, have been described for {sup 147}Gd nucleus during the {sup 122}Sn({sup 30}Si,5n) fusion-evaporation reaction in a 155 MeV bombardment energy. Dynamic inertia momentum similarities and gamma transition energy similarities have been observed between band I and {sup 148}Gd nucleus and between band II and {sup 146}Gd nucleus, respectively. These similarities can be related to a pseudo-spin symmetry. Calculations suggest the existence of an octupolar susceptibility in this mass region. {sup 144}Gd nucleus has been studied using {sup 120}Sn({sup 29}Si,5n) fusion-evaporation reaction in a 155 MeV bombardment energy and using {sup 100}Mo({sup 48}Ti,4n) reactions in a 200 MeV bombardment energy. {gamma}-{gamma} coincidences have revealed the existence of a 58 keV width valley in the matrix representation compatible with theoretical predictions. In spite of the evidence for about ten transitions during these experiments, no superdeformed structure has been demonstrated for {sup 144}Gd nucleus. (J.S.). 87 refs., 57 figs., 41 tabs.

Isomer decay spectroscopy of 164Sm and 166Gd: midshell collectivity around N=100.

Science.gov (United States)

Patel, Z; Söderström, P-A; Podolyák, Zs; Regan, P H; Walker, P M; Watanabe, H; Ideguchi, E; Simpson, G S; Liu, H L; Nishimura, S; Wu, Q; Xu, F R; Browne, F; Doornenbal, P; Lorusso, G; Rice, S; Sinclair, L; Sumikama, T; Wu, J; Xu, Z Y; Aoi, N; Baba, H; Bello Garrote, F L; Benzoni, G; Daido, R; Fang, Y; Fukuda, N; Gey, G; Go, S; Gottardo, A; Inabe, N; Isobe, T; Kameda, D; Kobayashi, K; Kobayashi, M; Komatsubara, T; Kojouharov, I; Kubo, T; Kurz, N; Kuti, I; Li, Z; Matsushita, M; Michimasa, S; Moon, C-B; Nishibata, H; Nishizuka, I; Odahara, A; Şahin, E; Sakurai, H; Schaffner, H; Suzuki, H; Takeda, H; Tanaka, M; Taprogge, J; Vajta, Zs; Yagi, A; Yokoyama, R

2014-12-31

Excited states in the N=102 isotones 166Gd and 164Sm have been observed following isomeric decay for the first time at RIBF, RIKEN. The half-lives of the isomeric states have been measured to be 950(60) and 600(140) ns for 166Gd and 164Sm, respectively. Based on the decay patterns and potential energy surface calculations, including β6 deformation, a spin and parity of 6- has been assigned to the isomeric states in both nuclei. Collective observables are discussed in light of the systematics of the region, giving insight into nuclear shape evolution. The decrease in the ground-band energies of 166Gd and 164Sm (N=102) compared to 164Gd and 162Sm (N=100), respectively, presents evidence for the predicted deformed shell closure at N=100.

Isomer Decay Spectroscopy of Sm 164 and Gd 166 : Midshell Collectivity Around N =100

Science.gov (United States)

Patel, Z.; Söderström, P.-A.; Podolyák, Zs.; Regan, P. H.; Walker, P. M.; Watanabe, H.; Ideguchi, E.; Simpson, G. S.; Liu, H. L.; Nishimura, S.; Wu, Q.; Xu, F. R.; Browne, F.; Doornenbal, P.; Lorusso, G.; Rice, S.; Sinclair, L.; Sumikama, T.; Wu, J.; Xu, Z. Y.; Aoi, N.; Baba, H.; Bello Garrote, F. L.; Benzoni, G.; Daido, R.; Fang, Y.; Fukuda, N.; Gey, G.; Go, S.; Gottardo, A.; Inabe, N.; Isobe, T.; Kameda, D.; Kobayashi, K.; Kobayashi, M.; Komatsubara, T.; Kojouharov, I.; Kubo, T.; Kurz, N.; Kuti, I.; Li, Z.; Matsushita, M.; Michimasa, S.; Moon, C.-B.; Nishibata, H.; Nishizuka, I.; Odahara, A.; Şahin, E.; Sakurai, H.; Schaffner, H.; Suzuki, H.; Takeda, H.; Tanaka, M.; Taprogge, J.; Vajta, Zs.; Yagi, A.; Yokoyama, R.

2014-12-01

Excited states in the N =102 isotones Gd 166 and Sm 164 have been observed following isomeric decay for the first time at RIBF, RIKEN. The half-lives of the isomeric states have been measured to be 950(60) and 600(140) ns for Gd 166 and Sm 164 , respectively. Based on the decay patterns and potential energy surface calculations, including β6 deformation, a spin and parity of 6- has been assigned to the isomeric states in both nuclei. Collective observables are discussed in light of the systematics of the region, giving insight into nuclear shape evolution. The decrease in the ground-band energies of Gd 166 and Sm 164 (N =102 ) compared to Gd 164 and Sm 162 (N =100 ), respectively, presents evidence for the predicted deformed shell closure at N =100 .

Recovery of uranium from (U,Gd)O{sub 2} nuclear fuel scrap using dissolution and precipitation in carbonate media

Energy Technology Data Exchange (ETDEWEB)

Kim, Kwang-Wook, E-mail: nkwkim@kaeri.re.kr [Korea Atomic Energy Research Institute, 1045 Daedeok daero, Yuseong, Daejeon 305-353 (Korea, Republic of); KEPCO NF 1047 Daedeok daero, Yuseong, Daejeon 305-353 (Korea, Republic of); Hyun, Jun-Taek; Lee, Eil-Hee; Park, Geun-Il; Lee, Kune-Woo [Korea Atomic Energy Research Institute, 1045 Daedeok daero, Yuseong, Daejeon 305-353 (Korea, Republic of); Yoo, Myung-June [KEPCO NF 1047 Daedeok daero, Yuseong, Daejeon 305-353 (Korea, Republic of); Song, Kee-Chan; Moon, Jei-Kwon [Korea Atomic Energy Research Institute, 1045 Daedeok daero, Yuseong, Daejeon 305-353 (Korea, Republic of)

2011-11-15

Highlights: > A treatment of (U,Gd)O{sub 2} scrap with a dissolution in carbonate solution with H{sub 2}O{sub 2}. > Partial dissolution of Gd together with uranium in carbonate solution. > Solubilities of Gd in solutions with and without carbonate at several pHs. > Purification of Gd-contaminated UO{sub 4} by dissolution and precipitation of UO{sub 4}. - Abstract: This work studied a process to recover uranium from contaminated (U,Gd)O{sub 2} scraps generated from nuclear fuel fabrication processes by using the dissolution of (U,Gd)O{sub 2} scraps in a carbonate with H{sub 2}O{sub 2} and the precipitation of the dissolved uranium as UO{sub 4}. The dissolution characteristics of uranium, Gd, and impurity metal oxides were tested, and the behaviors of UO{sub 4} precipitation and Gd solubility were evaluated with changes of the pH of the solution. A little Gd was entrained in the UO{sub 4} precipitate to contaminate the uranium precipitate. Below a pH of 3, the uranium dissolved in the form of uranyl peroxo-carbonato complex ions in the carbonate solution was precipitated as UO{sub 4} with a high precipitation yield, and the Gd had a very high solubility. Using these characteristics, the Gd-contaminated UO{sub 4} could be purified using dissolution in a 1-M HNO{sub 3} solution with heating and re-precipitation upon addition of H{sub 2}O{sub 2} to the solution. Finally, an environmentally friendly and economical process to recover pure uranium from contaminated (U,Gd)O{sub 2} scraps was suggested.

Determination of critical exponents of inhomogeneous Gd films

Energy Technology Data Exchange (ETDEWEB)

Rosales-Rivera, A., E-mail: arosalesr@unal.edu.co [Laboratorio de Magnetismo y Materiales Avanzados, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Colombia, Sede Manizales, Manizales (Colombia); Salazar, N.A. [Laboratorio de Magnetismo y Materiales Avanzados, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Colombia, Sede Manizales, Manizales (Colombia); Hovorka, O.; Idigoras, O.; Berger, A. [CIC nanoGUNE Consolider, Tolosa Hiribidea 76, E-20018 Donostia-San Sebastian (Spain)

2012-08-15

The role of inhomogeneity on the critical behavior is studied for non-epitaxial Gd films. For this purpose, the film inhomogeneity was varied experimentally by annealing otherwise identical samples at different temperatures T{sub AN}=200, 400, and 500 Degree-Sign C. Vibrating sample magnetometry (VSM) was used for magnetization M vs. T measurements at different external fields H. A method based upon the linear superposition of different sample parts having different Curie temperatures T{sub C} was used to extract the critical exponents and the intrinsic distribution of Curie temperatures. We found that this method allows extracting reliable values of the critical exponents for all annealing temperatures, which enabled us to study the effects of disorder onto the universality class of Gd films.

Determination of critical exponents of inhomogeneous Gd films

International Nuclear Information System (INIS)

Rosales-Rivera, A.; Salazar, N.A.; Hovorka, O.; Idigoras, O.; Berger, A.

2012-01-01

The role of inhomogeneity on the critical behavior is studied for non-epitaxial Gd films. For this purpose, the film inhomogeneity was varied experimentally by annealing otherwise identical samples at different temperatures T AN =200, 400, and 500 °C. Vibrating sample magnetometry (VSM) was used for magnetization M vs. T measurements at different external fields H. A method based upon the linear superposition of different sample parts having different Curie temperatures T C was used to extract the critical exponents and the intrinsic distribution of Curie temperatures. We found that this method allows extracting reliable values of the critical exponents for all annealing temperatures, which enabled us to study the effects of disorder onto the universality class of Gd films.

Vacuum ultraviolet excited luminescence properties of sol–gel derived GdP5O14:Eu3+ powders

International Nuclear Information System (INIS)

Mbarek, Aïcha; Chadeyron, Geneviève; Boyer, Damien; Avignant, Daniel; Fourati, Mohieddine; Zambon, Daniel

2014-01-01

Sol–gel route has successfully been used to synthesize pure and Eu 3+ doped polycrystalline samples of the GdP 5 O 14 pentaphosphates. The as-prepared samples have structurally been characterized using X-ray diffraction. Optical properties in the vacuum ultraviolet (VUV) of Eu 3+ activated GdP 5 O 14 samples prepared either by sol–gel process or solid-state reaction were investigated at room temperature for comparison. In this GdP 5 O 14 host matrix the P 5 O 14 ultraphosphate groups were proved to exhibit an efficient absorption in the VUV range. The excitation spectra recorded in the VUV-UV spectral region from 120 nm to 350 nm have revealed the presence of Gd 3+ 4f–5d interconfiguration transitions, Gd 3+ –O 2− and Eu 3+ –O 2− charge transfer states(CTS)in addition to intraconfiguration transitions of Gd 3+ ions.Furthermore the Gd 3+ →Eu 3+ energy transfer process was investigated and discussed in the framework of the multiphonon relaxation process. Besides, the GdP 5 O 14 :Eu 3+ phosphor led to a strong red emission under 147/172 nm excitation, so that it can be considered as a promising red phosphor for mercury-free lamps and plasma display panels applications. -- Highlights: • Lanthanide pentaphosphates were synthesized by the sol–gel process. • A broad absorption was evidenced in the VUV range for GdP 5 O 14 :Eu 3+ . • An efficient energy transfer was proved from pentaphosphate lattice to Eu 3+ ions

Magnetic short range order in Gd

International Nuclear Information System (INIS)

Child, H.R.

1976-01-01

Quasielastic neutron scattering has been used to investigate magnetic short range order in Gd for 80 0 K 0 K. Short range order exists throughout this range from well below T/sub C/ = 291 0 K to well above it and can be reasonably well described by an anisotropic Orstein-Zernike form for chi

Synthesis and luminescence properties of BaTiO3:RE (RE = Gd , Dy ...

Indian Academy of Sciences (India)

thermoluminescence (TL) properties of BaTiO3 samples doped with Gd3+, Dy3+, Tb3+ and Lu3+ were investigated. ... electron microscope using an accelerating voltage of 20 kV. .... doping of 1% mole Gd3+ ion into the BaTiO3 compound.

Effect of Gd{sup 3+} doping and reaction temperature on structural and optical properties of CdS nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Pandey, Gajanan, E-mail: pandeygajanan@rediffmail.com [Department of Applied Chemistry, Babasaheb Bhimrao Ambedkar University, Lucknow, 226025, (U.P.) (India); Dixit, Supriya; Shrivastava, A.K. [School of Studies in Physics, Jiwaji University, Gwalior, 474011, (M.P.) (India)

2015-10-15

Graphical abstract: - Highlights: • Cd{sub 1−x}Gd{sub x}S nanoparticles have been prepared in aqueous medium in presence of CTAB. • From XRD, EDX and ICP-OES study, successful doping of Gd{sup 3+} in CdS has been proved. • Gd{sup 3+} doping reduced size of NCs, while temperature increased size and altered shape. • Gd{sup 3+} doping and reaction temperature influenced the optical properties of NCs. - Abstract: CdS and Gd{sup 3+} ions doped CdS nanoparticles have been prepared at two reaction temperatures 90 and 120 °C in aqueous medium in presence of cationic surfactant cetyltrimethylammonium bromide. X-ray diffraction study revealed predominant formation of zinc blend CdS and Gd:CdS at 90 °C, while at 120 °C, phase pure wurtzite CdS and Gd:CdS were formed. From EDX spectra and ICP-OES analysis, successful doping of Gd{sup 3+} ions in CdS host has been proved. Fourier transform infrared spectroscopy results show the interaction of CTAB through headgroup at the nanoparticles surface. In the transmission electron microscopy images, it has been observed that the reaction temperature and Gd{sup 3+} doping played critical role on size and shape of nanocrystals. In UV–visible absorption as well as photoluminescence emission spectra, size and shape-dependent quantum confinement effect has been observed. On Gd{sup 3+} doping, surface states related emission peak shifted to higher wavelength, while intensity of peaks increased on increasing temperature.

Un nouveau béton auto-cicatrisant grâce à l’incorporation de bactéries

NARCIS (Netherlands)

Wiktor, V.; Jonkers, H.M.

2011-01-01

La formation d’un réseau continu de fissures contribue à l’augmentation de la perméabilité du béton, réduisant ainsi de manière importante sa résistance à l’attaque d’agents agressifs dissous dans l’eau. Afin d’augmenter la capacité de cicatrisation autogène du béton, certains agents cicatrisants

Detection of hepatocellular carcinoma: comparison of Gd-DTPA- and ferumoxides-enhanced MR imaging

International Nuclear Information System (INIS)

Simon, G.; Link, T.M.; Daldrup-Link, H.; Settles, M.; Woertler, K.; Doebereiner, F.; Schulte-Frohlinde, E.; Rummeny, E.J.

2005-01-01

The aim was to compare the diagnostic performance of dynamic Gd-DTPA- and ferumoxides-enhanced MRI for hepatocellular carcinoma (HCC). Twenty-five patients with chronic hepatitis or liver cirrhosis underwent both dynamic gadopentetate- and ferumoxides-enhanced MRI studies of the liver for HCC detection on the same day. MR data of both studies were retrospectively and independently analyzed. Two observers determined in consensus the grade of diffuse fibrotic liver changes (mild, moderate or severe) and the number of focal lesions. HCCs were confirmed by histology (n=22) and/or follow-up studies for at least six months (n=64). Differences in results obtained from both MR data sets were tested for significance with the McNemar's test (p 0.05) and Gd-DTPA-enhanced scans (94.2%). Gd-DTPA- and ferumoxides-enhanced MRI perform equally well for HCC detection. The majority of small hypervascular hepatic lesions, detected on dynamic Gd-DTPA-enhanced MRI but not on ferumoxides-enhanced MRI, represent no HCCs. (orig.)

Thermal conductivity of ferrimagnet GdBaMn2O5.0 single crystals

Directory of Open Access Journals (Sweden)

J. C. Wu

2017-05-01

Full Text Available GdBaMn2O5.0 is a double-perovskite ferrimagnet consisting of pyramidal manganese layers. In this work, we study the in-plane and the c-axis thermal conductivities of GdBaMn2O5.0 single crystals at low temperatures down to 0.3 K and in high magnetic fields up to 14 T. The κc(T curve shows a broad hump below the Néel temperature (TN = 144 K, which indicates the magnon heat transport along the c axis. Whereas, the κa(T shows a kink at TN, caused by a magnon-phonon scattering effect. This anisotropic behavior is caused by the anisotropy of spin interactions along different directions. At very low temperatures, magnetic-field-induced changes of κa and κc, which is likely due to phonon scattering by free Gd3+ spins, is rather weak. This indicates that the spin coupling between Gd3+ and Mn2+/Mn3+ is rather strong at low temperatures.

Efficacy of Gd-DTPA-enhanced MRI in hypertrophic cardiomyopathy

International Nuclear Information System (INIS)

Okamoto, Shinya; Aoki, Toshikazu; Konishi, Tokuji; Nakano, Takeshi; Yamakado, Kyoichiro; Sakuma, Hajime; Takeda, Kann; Nakagawa, Takashi

1991-01-01

The cabability of magnetic resonance (MR) imaging to detect tissue characterization or myocardial degeneration process of the hypertrophied myocardium was evaluated in 15 patients with hypertrophic cardiomyopathy. T1-weighted MR images were obtained with a 1.5 T MR unit by using ECG-gated spin-echo techniques. MR images were visually reviewed before and after enhancement of Gd-DTPA. Four patients had an increase in signal intensity mainly in the endocardium of the left ventricular septum on non-enhanced MR images, 3 of whom had widespread high intensity in addition to two-thirds of the wall. Gd-DTPA enhanced-MR images showed high intensity over the whole septum in 5 patients and also in the antero-lateral endocardium in 4 patients. Decreased intensity on non-enhanced MR images, as shown in 4 patients, became clear on enhanced-MR images. According to findings on enhanced-MR images, signal intensity was defined as normal (N), septum (S), and diffuse (D). Patients in Group D tended to be younger and have more frequently family history. Regarding both interventricular septum thickness and left ventricular posterior wall thickness, there was no significant difference among the three groups. Both left ventricular diastolic diameter and left ventricular systolic diameter were significantly larger in Group D than the other two groups. Left ventricular ejection fraction was significantly lower in both Group S and Group D. Widespread abnormal intensity on Gd-DTPA enhanced MR images was associated with findings similar to dilated cardiomyopathy, such as dilated left ventricular lumen and decreased ejection fraction. Gd-DTPA enhanced MR imaging seemed to be useful for visualizing myocardial degeneration in hypertrophic cardiomyopathy.(N.K.)

Gd-DTPA MR imaging enhancement of spinal cord tumors

International Nuclear Information System (INIS)

Dillon, W.P.; Bolla, K.; Mark, A.S.; Tsudura, J.S.; Norman, D.; Newton, T.H.

1987-01-01

Nineteen patients with suspected spinal cord tumors were imaged with T1- and T2-weighted sequences before and after the administration of Gd-DTPA (0.1 mmol/kg). Eleven of the 19 patients had spinal cord tumors (three unproven). Eight of 11 patients had intramedullary tumors (four astrocytomas, two ependymomas) and two had extra-medullary tumors (one meningioma, one metastatic melanoma). Other lesions studied include idiopathic syringomyelia (two), spinal arteriovenous malformation (AVM) (one), posttraumatic arachnoiditis (one), and cord infarct (one). All of the tumors enhanced after the administration of Gd-DTPA. Spinal cord enhancement was also noted in association with a spinal cord AVM, a suspected cord infarct, and in the patient with severe arachnoiditis. No enhancement was present in patients with idiopathic or posttraumatic syringomyelia or in the three normal patients. In six of the patients, enhancement was critical in confirming disease that was questionable on the precontrast MR images. Gadolinium enhancement allowed differentiation of tumor from postoperative changes in two patients with spinal cord tumors. Enhanced images localized the lesion more accurately than precontrast MR images in eight patients. In four patients a lesion could only be detected after the administration of contrast. The postcontrast images better defined the margin of tumor from surrounding edema, operative scarring, and cord cavitation. The AVM case had enhancement of slowly flowing veins with Gd-DTPA posterior to an ischemic cord segment. Gd-DTPA enhancement is extremely useful in the detection and therapeutic assessment of spinal cord tumors; however, enhancement is not specific for tumors and should be interpreted in light of the clinical setting

Ageing and memory effects in the weak random anisotropy magnets amorphous NdGdFe and HoGdFe

International Nuclear Information System (INIS)

Saito, Toshiaki; Emura, Ai; Hanashima, Koji

2007-01-01

We experimentally examined the ageing phenomena in typical weak random anisotropy magnets (weak RAMs), amorphous NdGdFe and HoGdFe, with a small ratio of the random anisotropy (D) to the ferromagnetic exchange (J) (D/J). These weak RAMs have very long average relaxation time, two or three orders longer than that of spin glasses (SGs) around the transition temperature, and also have a very large ac excitation field (h 0 ) dependence of the ac susceptibility. Measuring the imaginary part of the ac susceptibility at frequency of 0.5 Hz and h 0 of 0.3 Oe by using two temperature-change protocols, we observed the memory and rejuvenation effects as reported in SGs, but the effects are weaker in the present weak RAMs, suggesting that the picture of the hierarchical structure of the free energy space is also effective in weak RAMs as in SGs, but it may have smaller barrier heights than those of SGs

Growth and structural characterization of single crystals of the magnetic superconductor Ru1-xSr2-yGd1+yCu2+xO8-δ (RuGd-1212) obtained by the partial melting technique

Science.gov (United States)

Yamaki, K.; Bamba, Y.; Mochiku, T.; Funahashi, S.; Matsushita, Y.; Irie, A.

2018-05-01

In this study, cubic single crystals of the magnetic superconductor Ru1-xSr2-yGd1+yCu2+xO8-δ (RuGd-1212) with typical dimensions of 100-150 μm in length were grown by the partial melting technique. Multiple 00l reflections were first observed by XRD measurements of the bulk RuGd-1212 single crystals. The resistivity of the obtained crystals was roughly estimated to be ∼24-80 mΩ cm and no superconducting transition was observed down to 4.2 K. From the XRD measurements and refinement of the crystal structure, it was apparent that the Ru and Sr sites of the single-crystal RuGd-1212 were partially substituted by Cu and Gd, respectively. Oxygen defects were found to be minor (δ ≈ 0.1). The lattice parameters a and c of the single crystals were found to be larger and smaller, respectively, than those of a polycrystalline sample.

Optimising the design of paramagnetic MRI contrast agents: influence of backbone substitution on the water exchange rate of Gd-DTPA derivatives.

Science.gov (United States)

Laurent, S; Botteman, F; Vander Elst, L; Muller, R N

2004-04-01

Among other factors influencing the residence time of the coordinated water (tauM) of paramagnetic contrast agents, the steric hindrance around the gadolinium ion seems to play a beneficial role. Such a crowding can be achieved by substituting the Gd-DTPA backbone on the C4 position. Several Gd-DTPA complexes carrying diverse groups at this position have thus been synthesised and characterised: GdS-C4-Me-DTPA, GdS-C4-n-Bu-DTPA, GdS-C4-iBu-DTPA, GdS-C4-iPr-DTPA, and Gd-C4-diMe-DTPA. TauM has been measured through the evolution of the water oxygen-17 transverse relaxation rate as a function of the temperature. The data show a reduction of tauM of GdS-C4-Me-DTPA, GdS-C4-n-Bu-DTPA, GdS-C4-iBu-DTPA, GdS-C4-iPr-DTPA, and Gd-C4-diMe-DTPA (tauM310 = 91,82, 108,98, and 57 ns respectively, as compared to Gd-DTPA (tauM310 = 143 ns)). At 310 K, the nuclear magnetic dispersion relaxation profiles of water protons are very similar for the five complexes which present longitudinal relaxivities slightly higher than those of Gd-DTPA. Regarding zinc transmetallation, C4-monosubstituted derivatives are more stable than Gd-DTPA. These results confirm that a judicious substitution of the DTPA skeleton allows for an acceleration of the coordinated water exchange rate. This observation can be useful for the design of vectorised contrast agents for molecular imaging. Copyright 2004 ESMRMB

Sequential MR images of uterus after Gd-DTPA injection

International Nuclear Information System (INIS)

Okada, Susumu; Kato, Tomoyasu; Yamada, Keiko; Sawano, Seishi; Yamashita, Takashi; Hirai, Yasuo; Hasumi, Katsuhiko

1993-01-01

To investigate the sequential changes in signal intensity (SI) of normal and abnormal uteri, T1-weighted images were taken repeatedly after the injection of Gd-diethylenetriaminepentaacetic acid (DTPA). Six volunteers and 19 patients with known uterine body malignancy (18 carcinomas, one carcinosarcoma) were examined. The results in volunteers were as follows. In the secretory phase, SI of the endometrium was stronger in the late images than in the early ones, whereas in the proliferative phase, SI was stronger in the early images. SI of the myometrium decreased rapidly and there were no differences in SI between menstrual phases. In 17 of 18 endometrial carcinomas, the tumors showed hypointensity relative to the myometrium, and the contrast between the tumor and the myometrium was better in the early images. In the remaining two cases, the tumor showed hyperintensity and the contrast was better in the late images. After the injection of Gd-DTPA, the endometrium appeared differently according to the menstrual cycle in normal volunteers, and the appearance of uterine structures and endometrial malignant tumors changed sequentially. These findings must be kept in mind when evaluating uterine diseases by Gd-DTPA enhanced MRI. (author)

The Gd-isotopic fuel for high burnup in PWR's

International Nuclear Information System (INIS)

Dias, Marcio Soares; Mattos, João Roberto L. de; Andrade, Edison Pereira de

2017-01-01

Today, the discussion about the high burnup fuel is beyond the current fuel enrichment licensing and burnup limits. Licensing issues and material/design developments are again key features in further development of the LWR fuel design. Nevertheless, technological and economical solutions are already available or will be available in a short time. In order to prevent the growth of the technological gap, Brazil's nuclear sector needs to invest in the training of new human resources, in the access to international databases, and in the upgrading existing infrastructure. Experimental database and R&D infrastructure are essential components to support the autonomous development of Brazilian Nuclear Reactors, promoting the development of national technologies. The (U,Gd)O_2 isotopic fuel proposed by the CDTN's staff solve two main issues in the high burnup fuel, which are (1) the peak of reactivity resulting from the Gd-157 fast burnup, and (2) the peak of temperature in the (U,Gd)O_2 nuclear fuel resulting from detrimental effects in the thermal properties for gadolinia additions higher than 2%. A sustainable future can be envisaged for the nuclear energy. (author)

Diabetes\tand\tdepression:\tA\treview\twith\tspecial\tfocus\ton\tIndia

Directory of Open Access Journals (Sweden)

Megha\tThakur

2015-10-01

Full Text Available Diabetes,\ta\tpsychologically\tchallenging\tcondition for the\tpatients\tand their care givers, has been found to be a significant risk factor for depression. Depression\tmay\tbe\ta\tcritical\tbarrier\tto\teffective\tdiabetes\tmanagement.\tThe accompanying\tfatigue\tremarkably\tlowers\tthe\tmotivation\tfor\tself-care,\toften leading to lowered physical and emotion well-being, poor markers of diabetes control, poor adherence to medication, and increased mortality among individuals with diabetes. A very small proportion of the diabetes patients\twith\tdepression\tget\tdiagnosed,\tand\tfurthermore,\tonly\ta\thandful\tof the ones diagnosed get treated for depression. Despite the fact that 80 percent\tof\tthe\tpeople\twith\ttype\t2\tdiabetes\treside\tin\tlow\tand\tmiddle\tincome\tcountries,\tmost\tof\tthe\tevidence\ton diabetes\tand\tdepression\tcomes\tfrom\thigh\tincome\tcountries.\tThis\treview\toffers\ta\tsummary\tof\texisting\tevidence and\tthe\tpotential\tgaps\tthat\tneed\tto\tbe\taddressed.

T1-T2 dual-modal MRI of brain gliomas using PEGylated Gd-doped iron oxide nanoparticles.

Science.gov (United States)

Xiao, Ning; Gu, Wei; Wang, Hao; Deng, Yunlong; Shi, Xin; Ye, Ling

2014-03-01

To overcome the negative contrast limitations of iron oxide-based contrast agents and to improve the biocompatibility of Gd-chelate contrast agents, PEGylated Gd-doped iron oxide (PEG-GdIO) NPs as a T1-T2 dual-modal contrast agent were synthesized by the polyol method. The transverse relaxivity (r2) and longitudinal relaxivity (r1) of PEG-GdIO were determined to be 66.9 and 65.9 mM(-1) s(-1), respectively. The high r1 value and low r2/r1 ratio make PEG-GdIO NPs suitable as a T1-T2 dual-modal contrast agent. The in vivo MRI demonstrated a brighter contrast enhancement in T1-weighted image and a simultaneous darken effect in T2-weighted MR image compared to the pre-contrast image in the region of glioma. Furthermore, the biocompatibility of PEG-GdIO NPs was confirmed by the in vitro MTT cytotoxicity and in vivo histological analyses (H&E). Therefore, PEG-GdIO NPs hold great potential in T1-T2 dual-modal imaging for the diagnosis of brain glioma. Copyright © 2013 Elsevier Inc. All rights reserved.

Hypoeutectic melting in the UO{sub 2-x}-Gd{sub 2}O{sub 3} system

Energy Technology Data Exchange (ETDEWEB)

Journeau, Christophe, E-mail: christophe.journeau@cea.fr [CEA, DEN, SMTA, LPMA, Cadarache, F13108 St Paul lez Durance (France); Fouquart, Pascal [CEA, DEN, SMTA, LPMA, Cadarache, F13108 St Paul lez Durance (France); Domenger, Renaud; Allegri, Patrick [CEA, DEN, SGCS, LMAC, Marcoule, F30207 Bagnols sur Cèze (France)

2017-05-15

Gadolinium is one of the best neutron absorber materials and its use can be considered as a sacrificial material in a Sodium Fast Reactor core catcher in view of preventing recriticallity. A series of experiments have been conducted in the VITI induction-heated facility to study the melting in the UO{sub 2-x}-Gd{sub 2}O{sub 3} system with 60–87 mol% gadolinia. These experiments have indicated that the eutectic composition is around 92 mol% Gd{sub 2}O{sub 3} – 8 mol% UO{sub 2-x} and that the liquidus line is close to that of Popov et al. [Atom. Energ. 110 (2011) pp. 221–229] phase diagram. - Highlights: •Melting/Solidification experiments with UO{sub 2-x} and Gd{sub 2}O{sub 3} in reducing environment. •Eutectic composition around 92 mol% Gd{sub 2}O{sub 3}-8 mol% UO{sub 2-x}. •UO{sub 2-x} - Gd{sub 2}O{sub 3} liquidus line seems close to that of the pseudobinary phase diagram proposed by Popov et al. •Results will support the assessment of Gd{sub 2}O{sub 3} as a sacrificial material to mitigate criticality risk in SFR core catchers.

Melt-processed Gd-Ba-Cu-O superconductor with trapped field of 3 T at 77 K

International Nuclear Information System (INIS)

Nariki, S; Sakai, N; Murakami, M

2005-01-01

We fabricated a single-domain Gd-Ba-Cu-O bulk superconductor 65 mm in diameter and studied the microstructure, superconducting and field-trapping properties. Melt-processing was performed under a controlled oxygen partial pressure of 1.0% using a precursor containing Gd123 and Gd211 powders in a molar ratio of 2:1, with 0.5 wt% of Pt and 20 wt% of Ag 2 O added. The distribution of Ag and Gd211 particles was almost homogeneous. The addition of Ag was very effective in reducing the amount of cracking in the sample. The maximum trapped magnetic field recorded was 3.05 T at 77 K. We also measured the trapped field between two Gd-Ba-Cu-O bulk samples in order to minimize the demagnetizing effect and found that the trapped field reached 4.3 T at 77 K

Luminescence study of Eu3+ doped GdVO4 nanoparticles: Concentration, particle size, and core/shell effects

Science.gov (United States)

Singh, N. Shanta; Ningthoujam, R. S.; Devi, L. Romila; Yaiphaba, N.; Sudarsan, V.; Singh, S. Dorendrajit; Vatsa, R. K.; Tewari, R.

2008-11-01

Nanoparticles of GdVO4 doped with Eu3+ and core/shell of GdVO4:Eu3+/GdVO4 are prepared by urea hydrolysis method using ethylene glycol as capping agent as well as reaction medium at 130 °C. Unit cell volume increases when GdVO4 is doped with Eu3+ indicating the substitution of Gd3+ lattice sites by Eu3+. From luminescence study, it is confirmed that there is no particle size effect on emission positions of Eu3+. Optimum luminescence intensity is found to be in 5-10 at. % Eu3+. Above these concentrations, luminescence intensity decreases due to concentration quenching effect. There is an enhancement in luminescence intensity of core/shell nanoparticles. This has been attributed to the reduction in surface inhomogenities of Eu3+ surroundings by bonding to GdVO4 shell. The lifetime for D50 level increases with annealing and core/shell formation.

Mid-Infrared Observations of the White Dwarf Brown Dwarf Binary GD 1400

OpenAIRE

Farihi, J.; Zuckerman, B.; Becklin, E. E.

2005-01-01

Fluxes are measured for the DA white dwarf plus brown dwarf pair GD 1400 with the Infrared Array Camera on the {\\em Spitzer Space Telescope}. GD 1400 displays an infrared excess over the entire $3-8\\mu$m region consistent with the presence of a mid- to late-type L dwarf companion. A discussion is given regarding current knowledge of this unique system.

Degeneration of uterine leiomyoma: comparison between Gd-DTPA enhanced MR imaging and pathologic findings

International Nuclear Information System (INIS)

Shin, M. J.; Kim, G. W.; No, T. Y.; Ahn, W. H.; Baik, S. K.; Kim, B. G.; Choi, H. Y.; Paik, O. J.

1995-01-01

Gonadotropin-releasing hormone(GnRH) analogues have been used as a conservative or preoperative therapy in the treatment of uterine leiomyoma. Since these drugs, which can induce a low estrogenic state, affect only undegenerative leiomyoma tissue, the aim of the present study was to differentiate degenerative leiomyoma from undegenerative one by Gd-DTPA enhanced magnetic resonance imaging(MRI). There were 40 masses in 24 patients; all were diagnosed by surgical-pathology. With superconductive 0.5T MR circuit, T1-and T2-weighted images and Gd-DTPA T1-weighted images were obtained. Based on a combination of signal intensities of T2-weighted and enhanced T1 weighted image on the same tumor section all the lesions were classified to one of four MRI patterns. Pattern I was a heterogeneous hyperintensity on the T2-weighted images that was enhancement by Gd-DTPA. Pattern II was a high signal intensity on the T2-weighted MR images but no enhancement by Gd-DTPA. Pattern III was a low to intermediate signal intensity on the T2-weighted MR images and enhancement on the Gd-DTPA T1-weighted images. Pattern IV was a low to intermediate signal intensity on the T2-weighted images and no enhancement by Gd-DTPA. Each of these 4 groups of MRI pattern were co-related to the surgical-pathology findings. Pathologically, pattern I corresponded to an edematous leiomyoma in 3 cases and a connective tissue leiomyoma in one case. Pattern II corresponded to three red degeneration, two cystic degeneration and one infected leiomyoma. Pattern III corresponded to eighteen undegenerative leiomyomas, but some of them showed focal connective tissue proliferation. All of twelve cases in pattern IV corresponded to a hyaline degeneration. MRI with Gd-DTPA enhancement may differentiate undegenerative leiomyoma from degenerated one

Degeneration of uterine leiomyoma: comparison between Gd-DTPA enhanced MR imaging and pathologic findings

Energy Technology Data Exchange (ETDEWEB)

Shin, M. J.; Kim, G. W.; No, T. Y.; Ahn, W. H.; Baik, S. K.; Kim, B. G.; Choi, H. Y.; Paik, O. J. [Wallace Memorial Baptist Hospital, Busan (Korea, Republic of)

1995-05-15

Gonadotropin-releasing hormone(GnRH) analogues have been used as a conservative or preoperative therapy in the treatment of uterine leiomyoma. Since these drugs, which can induce a low estrogenic state, affect only undegenerative leiomyoma tissue, the aim of the present study was to differentiate degenerative leiomyoma from undegenerative one by Gd-DTPA enhanced magnetic resonance imaging(MRI). There were 40 masses in 24 patients; all were diagnosed by surgical-pathology. With superconductive 0.5T MR circuit, T1-and T2-weighted images and Gd-DTPA T1-weighted images were obtained. Based on a combination of signal intensities of T2-weighted and enhanced T1 weighted image on the same tumor section all the lesions were classified to one of four MRI patterns. Pattern I was a heterogeneous hyperintensity on the T2-weighted images that was enhancement by Gd-DTPA. Pattern II was a high signal intensity on the T2-weighted MR images but no enhancement by Gd-DTPA. Pattern III was a low to intermediate signal intensity on the T2-weighted MR images and enhancement on the Gd-DTPA T1-weighted images. Pattern IV was a low to intermediate signal intensity on the T2-weighted images and no enhancement by Gd-DTPA. Each of these 4 groups of MRI pattern were co-related to the surgical-pathology findings. Pathologically, pattern I corresponded to an edematous leiomyoma in 3 cases and a connective tissue leiomyoma in one case. Pattern II corresponded to three red degeneration, two cystic degeneration and one infected leiomyoma. Pattern III corresponded to eighteen undegenerative leiomyomas, but some of them showed focal connective tissue proliferation. All of twelve cases in pattern IV corresponded to a hyaline degeneration. MRI with Gd-DTPA enhancement may differentiate undegenerative leiomyoma from degenerated one.

Micro structural and magnetic characterization of Gd doped SnO2 nanoparticles

International Nuclear Information System (INIS)

Adhikari, R.; Das, A.K.; Karmakar, D.; Chandrasekhar Rao, T.V.; Ghatak, J.

2008-01-01

Gd doped SnO 2 nanoparticles were prepared by a chemical co-precipitation method. The prepared samples were calcined at 600 deg C. The annealed samples were characterized using XRD, TEM and SQUID magnetometry. The structural characterizations showed formation of particles in the nanometer regime. The M(T) and M(H) studies indicated an antiferromagnetic (AFM) interaction in 3 and 6% (at. wt.) Gd doped SnO 2 nanoparticles. The M(H) plot of both samples indicate a super paramagnetic (SPM) behavior at 7K as against the perfect AFM nature at 300K. The samples exhibit an insulating DMS nature, but we do not observe any ferromagnetism as was observed for other Gd doped systems like GaN and ZnO. (author)

Low-lying dipole strength in the well-deformed nucleus {sup 156}Gd

Energy Technology Data Exchange (ETDEWEB)

Tamkas, M. [ExtreMe Matter Institute (EMMI), GSI, Darmstadt (Germany); Graduate School of Natural and Applied Sciences, Yildiz Technical University, Istanbul (Turkey); Isaak, J.; Silva, J. [ExtreMe Matter Institute (EMMI), GSI, Darmstadt (Germany); Frankfurt Institute for Advanced Studies (FIAS), Frankfurt (Germany); Savran, D. [ExtreMe Matter Institute (EMMI), GSI, Darmstadt (Germany); GSI Helmholtzzentrum fuer Schwerionenforschung, Darmstadt (Germany); Loeher, B. [GSI Helmholtzzentrum fuer Schwerionenforschung, Darmstadt (Germany); Aciksoz, E. [Department of Physics, Akdeniz University (Turkey); Beck, T.; Beller, J.; Gayer, U.; Pietralla, N.; Romig, C.; Werner, V.; Zweidinger, M. [Institut fuer Kernphysik, Technische Universitaet, Darmstadt (Germany); Tornow, W.; Weller, H. [Department of Physics, Duke University, TUNL, Durham (United States); Zilges, A. [Institut fuer Kernphysik, Universitaet zu Koeln (Germany)

2016-07-01

In this study the dipole strength has been investigated in the well-deformed nucleus {sup 156}Gd using the method of Nuclear Resonance Fluorescence (NRF). The NRF experiment was performed at the High Intensity vector γ-ray Source at Duke University in combination with the γ{sup 3} setup using a mono-energetic and linearly polarised beam. The dipole strength of {sup 156}Gd has been studied with photon beam energies between 3 MeV and 6.2 MeV. The parity quantum numbers of J=1 states have been determined for the energy region above ∝3 MeV for the first time. Recent results of the {sup 156}Gd(vector γ,γ') experiment are presented and discussed.

Activation of human naïve Th cells increases surface expression of GD3 and induces neoexpression of GD2 that colocalize with TCR clusters.

Science.gov (United States)

Villanueva-Cabello, Tania M; Mollicone, Rosella; Cruz-Muñoz, Mario E; López-Guerrero, Delia V; Martínez-Duncker, Iván

2015-12-01

CD4+ T helper lymphocytes (Th) orchestrate the immune response after their activation by antigen-presenting cells. Activation of naïve Th cells is reported to generate the reduction in surface epitopes of sialic acid (Sia) in α2,3 and α2,6 linkages. In this work, we report that in spite of this glycophenotype, anti-CD3/anti-CD28-activated purified human naïve Th cells show a significant increase in surface Sia, as assessed by metabolic labeling, compared with resting naïve Th cells, suggesting an increased flux of Sia toward Siaα2,8 glycoconjugates. To understand this increase as a result of ganglioside up-regulation, we observed that very early after activation, human naïve Th cells show an increased expression in surface GD3 and neoexpression of surface GD2 gangliosides, the latter clustering with the T cell receptor (TCR). Also, we report that in contrast to GM2/GD2 synthase null mice, lentiviral vector-mediated silencing of the GM2/GD2 synthase in activated human naïve Th cells reduced efficient TCR clustering and downstream signaling, as assessed by proliferation assays and IL-2 and IL-2R expression, pointing to an important role of this enzyme in activation of human naive Th cells. © The Author 2015. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Primed infusion with delayed equilibrium of Gd.DTPA for enhanced imaging of small pulmonary metastases.

Science.gov (United States)

Kalber, Tammy L; Campbell-Washburn, Adrienne E; Siow, Bernard M; Sage, Elizabeth; Price, Anthony N; Ordidge, Katherine L; Walker-Samuel, Simon; Janes, Sam M; Lythgoe, Mark F

2013-01-01

To use primed infusions of the magnetic resonance imaging (MRI) contrast agent Gd.DTPA (Magnevist), to achieve an equilibrium between blood and tissue (eqMRI). This may increase tumor Gd concentrations as a novel cancer imaging methodology for the enhancement of small tumor nodules within the low signal-to-noise background of the lung. A primed infusion with a delay before equilibrium (eqMRI) of the Gd(III) chelator Gd.DTPA, via the intraperitoneal route, was used to evaluate gadolinium tumor enhancement as a function of a bolus injection, which is applied routinely in the clinic, compared to gadolinium maintained at equilibrium. A double gated (respiration and cardiac) spin-echo sequence at 9.4T was used to evaluate whole lungs pre contrast and then at 15 (representative of bolus enhancement), 25 and 35 minutes (representative of eqMRI). This was carried out in two lung metastasis models representative of high and low tumor cell seeding. Lungs containing discrete tumor nodes where inflation fixed and taken for haematoxylin and eosin staining as well as CD34 staining for correlation to MRI. We demonstrate that sustained Gd enhancement, afforded by Gd equilibrium, increases the detection of pulmonary metastases compared to bolus enhancement and those tumors which enhance at equilibrium are sub-millimetre in size (<0.7 mm(2)) with a similar morphology to early bronchoalveolar cell carcinomas. As Gd-chelates are routinely used in the clinic for detecting tumors by MRI, this methodology is readily transferable to the clinic and advances MRI as a methodology for the detection of small pulmonary tumors.

Structural and magnetic properties of Gd1-xPrxMn2Si2 silicides

International Nuclear Information System (INIS)

Kilic, A.; Kervan, S.; Gencer, A.

2004-01-01

X-ray powder diffraction, AC susceptibility and differential scanning calorimetry (DSC) studies were performed on the polycrystalline Gd 1-x Pr x Mn 2 Si 2 (0≤x≤1) compounds. All compounds investigated crystallize in the body-centred tetragonal ThCr 2 Si 2 -type structure with the space group I4/mmm. Substitution of Pr for Gd leads to a linear increase of the lattice constants and the unit cell volume. The lattice constants and the unit cell volume obey Vegard's law. At the Curie temperature T C (Gd), the Gd sublattice orders and reconfigures the ordering in the Mn sublattice. This temperature becomes depressed and disappears with increasing Pr content x. The Neel temperature T N (Mn) determined by DSC technique decreases linearly with increasing Pr content x. The results are summarized in the x-T magnetic phase diagram

Neutron diffraction studies on GdB{sub 6} and TbB{sub 6} powders

Energy Technology Data Exchange (ETDEWEB)

Luca, S.E.; Amara, M.; Galera, R.M.; Givord, F.; Granovsky, S.; Isnard, O.; Beneu, B

2004-07-15

We report here the first powder neutron diffraction study of GdB{sub 6} and TbB{sub 6}. GdB{sub 6} and TbB{sub 6} order antiferromagnetically at 15 and 21 K, respectively. In both compounds the transition at T{sub N} is of the first order. Moreover GdB{sub 6} presents a second spontaneous magnetic transition at T{sup *}=8 K. The present study shows that, in both compounds, the magnetic propagation vectors belong to the <((1)/(4)) ((1)/(4)) ((1)/(2))> star and that the direction of the magnetic moment is perpendicular to the ((1)/(2)) component of the wave-vector in GdB{sub 6}, while in TbB{sub 6} the moment is parallel to it. The deduced low-temperature values of the magnetic moments agree with those of the respective rare-earth trivalent ions.

Electromagnetic transition probabilities in the natural-parity rotational bands of 155,157Gd

International Nuclear Information System (INIS)

Kusakari, H.; Oshima, M.; Uchikura, A.; Sugawara, M.; Tomotani, A.; Ichikawa, S.; Iimura, H.; Morikawa, T.; Inamura, T.; Matsuzaki, M.

1992-01-01

The ground-state rotational bands of 155 Gd and 157 Gd have been investigated through multiple Coulomb excitation with beams of 240-MeV 58 Ni and 305-MeV 81 Br. Gamma-ray branchings and E2/M1 mixing ratios were determined by γ-ray angular-distribution measurement. Nuclear lifetimes of levels up to I=21/2 and 23/2 for 155,157 Gd, respectively, have been measured using the Doppler-shift recoil-distance method. The observed signature dependence of M1 transition rates was found to be inverted in relation to the quasiparticle energy splitting. The data are analyzed in terms of the cranking model

Phase I trial of anti-GD2 monoclonal antibody hu3F8 plus GM-CSF: Impact of body weight, immunogenicity and anti-GD2 response on pharmacokinetics and survival.

Science.gov (United States)

Cheung, Irene Y; Kushner, Brian H; Modak, Shakeel; Basu, Ellen M; Roberts, Stephen S; Cheung, Nai-Kong V

2017-01-01

Fifty-seven stage 4 patients with refractory/relapsed neuroblastoma were enrolled in a phase I trial (Clinicaltrials.gov NCT01757626) using humanized anti-GD2 monoclonal antibody hu3F8 in combination with granulocyte-macrophage colony-stimulating factor. The influence of body weight and human anti-human antibody (HAHA) on the pharmacokinetics (PK) of hu3F8, and the effect of de novo anti-GD2 response on patient outcome were explored. Serum samples before hu3F8 infusion, and serially up to day 12 during treatment cycle #1, and at 5 min after each hu3F8 infusion for all subsequent cycles were collected. PK was analyzed using non-compartmental modeling. Immunogenicity was assayed by HAHA response, and vaccination effect by induced host anti-GD2 response measured periodically until disease progression or last followup. Progression-free and overall survival was estimated by the Kaplan-Meier method. Despite dosing being based on body weight, smaller patients had consistently lower area-under-the-curve and faster clearance over the 15 dose levels (0.9 to 9.6 mg/kg per treatment cycle) in this trial. Positive HAHA, defined by the upper limit of normal, when measured within 10 days from the last hu3F8 dose received, was associated with significantly lower serum hu3F8. Despite prior sensitization to other anti-GD2 antibody, e.g. mouse 3F8 or ch14.18, 75% of the patients never developed HAHA response even after getting more treatment cycles. Hu3F8 induced a de novo anti-GD2 response in patients, which was prognostic of progression-free survival. We conclude that hu3F8 had low immunogenicity. During treatment, positive HAHA and low body weight affected PK adversely, whereas induced anti-GD2 response was an outcome predictor.

Design and analysis of a 1-ton prototype of the Jinping Neutrino Experiment

International Nuclear Information System (INIS)

Wang, Zongyi; Wang, Yuanqing; Wang, Zhe; Chen, Shaomin; Du, Xinxi; Zhang, Tianxiong; Guo, Ziyi; Yuan, Huanxin

2017-01-01

The Jinping Neutrino Experiment will perform an in-depth research on solar neutrinos and geo-neutrinos. Two structural options (i.e., cylindrical and spherical schemes) are proposed for the Jinping detector based on other successful underground neutrino detectors. Several key factors in the design are also discussed in detail. A 1-ton prototype of the Jinping experiment is proposed based on physics requirements. Subsequently, the structural design, installation procedure, and mechanical analysis of the neutrino detector prototype are discussed. The results show that the maximum Mises stresses on the acrylic vessel, stainless steel truss, and the tank are all lower than the design values of the strengths. The stability requirement of the stainless steel truss in the detector prototype is satisfied. Consequently, the structural scheme for the 1-ton prototype is safe and reliable.

Design and analysis of a 1-ton prototype of the Jinping Neutrino Experiment

Energy Technology Data Exchange (ETDEWEB)

Wang, Zongyi, E-mail: wangzongyi1990@outlook.com [School of Civil Engineering, Wuhan University, Wuhan 430072 (China); Wang, Yuanqing [Key Laboratory of Civil Engineering Safety and Durability of Education Ministry, Tsinghua University, Beijing 100084 (China); Wang, Zhe; Chen, Shaomin [Department of Engineering Physics, Tsinghua University, Beijing 100084 (China); Du, Xinxi [School of Civil Engineering, Wuhan University, Wuhan 430072 (China); Zhang, Tianxiong [School of Civil Engineering, Tianjin University, Tianjin 300072 (China); Guo, Ziyi [Department of Engineering Physics, Tsinghua University, Beijing 100084 (China); Yuan, Huanxin [School of Civil Engineering, Wuhan University, Wuhan 430072 (China)

2017-05-21

The Jinping Neutrino Experiment will perform an in-depth research on solar neutrinos and geo-neutrinos. Two structural options (i.e., cylindrical and spherical schemes) are proposed for the Jinping detector based on other successful underground neutrino detectors. Several key factors in the design are also discussed in detail. A 1-ton prototype of the Jinping experiment is proposed based on physics requirements. Subsequently, the structural design, installation procedure, and mechanical analysis of the neutrino detector prototype are discussed. The results show that the maximum Mises stresses on the acrylic vessel, stainless steel truss, and the tank are all lower than the design values of the strengths. The stability requirement of the stainless steel truss in the detector prototype is satisfied. Consequently, the structural scheme for the 1-ton prototype is safe and reliable.

Development of organic MRI contrast agents

International Nuclear Information System (INIS)

Hayashi, Hiroyuki; Sato, Yuichiro; Karasawa, Satoru; Koga, Noboru

2008-01-01

Described are trends of the development in the title since those agents with target properties are awaited for specific organ and regional MRI. The contrast agents alter the relaxation time of water proton to yield the enhanced contrast between organs and tissues with different water volumes. Nowadays Gd-complexes and nano-particle of superparamagnetic iron oxide (Fe(III)) are widely used for enhancing in clinic. Among organic compounds with paramagnetic spin, those possessing nitroxide radical like TEMPO- and PROXYL-radicals have been subject to development by their derivatization. High spin molecules conceivably affect the relaxivity, which, however, is found smaller per spin of synthesized triplet complexes than doublet ones. This has lead to basic approach for molecules restricting water movement due to their hydrogen bond like DNA as a model, for introducing many radicals in high molecular weight compounds, and their polymer, as one of which authors have developed a derivative of hyperbranched polymer (HPS)-TEMPO having the similar relaxivity to gadolinium-diethylenetiamine pentaacetid acid (Gd-DTPA) (R.T.)

Structural and magnetic properties of Gd/Fe multilayers grown by pulsed laser deposition

DEFF Research Database (Denmark)

Kant, K. Mohan; Bahl, Christian Robert Haffenden; Pryds, Nini

2010-01-01

This work investigates the structural and the magnetic properties of Gd/Fe multilayered thin films grown by pulsed laser deposition onto Si (001) substrates at room temperature. he Fe layer thickness is varied from 70 to 150 nm and its effect on the structural and magnetic properties of Fe/Gd/Fe ...

Synthesis and study of bifunctional core–shell nanostructures based on ZnO@Gd{sub 2}O{sub 3}

Energy Technology Data Exchange (ETDEWEB)

Babayevska, Nataliya, E-mail: natbab@amu.edu.pl; Nowaczyk, Grzegorz; Jarek, Marcin; Załęski, Karol; Jurga, Stefan

2016-07-05

Bifunctional nanostructures based on ZnO nanoparticles (NPs) with controlled Gd{sub 2}O{sub 3} shell thicknesses were obtained by simple low-temperature methods (sol–gel technique and seed deposition method). The morphology, nanostructure, phase and chemical composition as well as luminescent and magnetic properties of the obtained core–shell nanostructures were investigated by transmission electron microscopy (HRTEM), energy dispersive x-ray spectroscopy (EDS), x-ray diffraction (XRD) techniques, optical spectroscopy, and SQUID magnetometer. As-obtained ZnO NPs are highly monodispersed and crystalline with mean particles size distribution of about 7 nm. Modification of the ZnO NPs surface by Gd{sub 2}O{sub 3} shell leads to an increase of the ZnO particles size up to 80–160 nm and the formation the Gd{sub 2}O{sub 3} shell with size of 2–4 nm. The dependence of the phase composition, luminescent and magnetic properties on Gd{sub 2}O{sub 3} content are also discussed. - Highlights: • The bifunctional ZnO@Gd{sub 2}O{sub 3} nanostructures were obtained by sol–gel technique. • ZnO@Gd{sub 2}O{sub 3} have intensive luminescence in the visible range under 325 nm excitation. • Gd{sup 3+} content allows to control paramagnetic properties of the ZnO@Gd{sub 2}O{sub 3}. • ZnO@Gd{sub 2}O{sub 3} nanostructures are potential objects for application in medicine.

The dependence of critical current density of GdFeCo layer on composition of thermally assisted STT-RAM

Science.gov (United States)

Dai, B.; Zhu, J.; Liu, K.; Yang, L.; Han, J.

2017-07-01

Amorphous rare earth-transitional metal (RETM) GdFeCo memory layer with RE- and TM-rich compositions was fabricated in stacks of GdFeCo (10 nm)/Cu (3 nm)/[Co(0.2 nm)/Pd(0.4 nm)]6. Their magnetic properties and spin transfer torque (STT) switching of magnetization were investigated. The maximum magneto-resistance (MR) was around 0.24% for the TM-rich Gd21.4 (Fe90Co10)78.6 memory layer and was -0.03% for the RE-rich Gd29.0 (Fe90Co10)71.0 memory layer. The critical current densities Jc to switch the GdFeCo memory layers are in the range of 1.4 × 107 A/cm2-4.5 × 107 A/cm2. The dependence of critical current density Jc and effective anisotropy constant Keff on Gd composition were also investigated. Both Jc and Keff have maximum values in the Gd composition range from 21-29 at.%, suitable for thermally assisted STT-RAM for storage density exceeding Gb/inch2.

Luminescent properties of Pr3+-sensitized LaPO4:Gd3+ ultraviolet-B phosphor under vacuum-ultraviolet light excitation

International Nuclear Information System (INIS)

Okamoto, Shinji; Uchino, Rika; Kobayashi, Keisuke; Yamamoto, Hajime

2009-01-01

Luminescent properties of Pr 3+ -sensitized LaPO 4 :Gd 3+ under vacuum-ultraviolet (vuv) light excitation have been investigated. The energy transfer probably occurs from the 5d levels in Pr 3+ ions to Gd 3+ ions under 172 nm light excitation. LaPO 4 :Gd 3+ ,Pr 3+ shows efficient ultraviolet-B (uv-B) emission at 312 nm, whose peak intensity reaches its maximum at Gd=35 mol % and Pr=5 mol %. (La 0.65 Gd 0.35 ) 0.95 Pr 0.05 PO 4 is about 1.6 times higher than a typical uv-B phosphor for vuv lamp, Y 0.75 Gd 0.25 Al 3 (BO 3 ) 4 , in Gd 3+ -emission intensity under 172 nm light excitation. This result implies that the Pr 3+ -sensitized LaPO 4 :Gd 3+ is a candidate of uv-B phosphors for xenon-excimer discharge vuv lamps. In order to evaluate the effect of the narrow-band uv-B emission by LaPO 4 :Gd 3+ ,Pr 3+ phosphor, irradiation test on DNA was performed. The irradiation damage of pUC 18 DNA by the narrow-band uv-B light from the LaPO 4 :Gd 3+ ,Pr 3+ phosphor is in the same magnitude as that by uv-A light from a filtered Hg lamp, even though the uv-B lamp is higher than the uv-A lamp in power density and photon energy.

Prognostic significance of highly sulfated chondroitin sulfates in ovarian cancer defined by the single chain antibody GD3A11.

Science.gov (United States)

van der Steen, Sophieke C H A; van Tilborg, Angela A G; Vallen, Myrtille J E; Bulten, Johan; van Kuppevelt, Toin H; Massuger, Leon F A G

2016-03-01

The extracellular matrix (ECM) of ovarian cancer may provide a number of potential biomarkers. Chondroitin sulfate (CS), a class of sulfated polysaccharides, is abundantly present in the ECM of ovarian cancer. Structural alterations of CS chains (i.e. sulfation pattern) have been demonstrated to play a role in cancer development and progression. In this study we investigate the potential of highly sulfated CS as a biomarker in ovarian cancer using the single chain antibody GD3A11 selected by the phage display technology. The specificity of the antibody was determined by an indirect ELISA. GD3A11 epitope expression was assessed by immunohistochemistry in healthy organs, benign and malignant ovarian tumors (N=359) and correlated to clinical parameters. The CHST15 gene, responsible for the biosynthesis of highly sulfated CS was evaluated for mutation and methylation status. The GD3A11 epitope was minimally expressed in normal organs. Intense expression was observed in the ECM of different ovarian cancer subtypes, in contrast to benign ovarian tumors. Expression was independent of tumor grade, FIGO stage, and the use chemotherapy. For the aggressive ovarian cancer phenotype, intense expression was identified as an independent predictor for poor prognosis. CHST15 gene analysis showed no mutations nor an altered methylation status. Specific highly sulfated CS motifs expressed in the tumoral ECM hold biomarker potential in ovarian cancer patients. These matrix motifs constitute a novel class of biomarkers with prognostic significance and may be instrumental for innovative diagnostic and therapeutic applications (e.g. targeted therapy) in management of ovarian cancer. Copyright © 2016 Elsevier Inc. All rights reserved.

Gd-DTPA: Clinical use in MR imaging of postoperative lumbar recurrent disk herniation and fibrosis

International Nuclear Information System (INIS)

Narang, A.K.; Hueftle, M.; Williams, A.; Modic, M.; Davis, D.O.

1987-01-01

Gd-DTPA, a paramagnetic MR contrast agent, is most familiarly utilized for delineation of brain and cord abnormalities. Since contrast-enhanced CT may help distinguish epidural fibrosis from recurrent herniated lumbar disk, the efficacy of Gd-DTPA-enhanced MR imaging was evaluated. Symptomatic patients with previous back surgery are being evaluated with pre- and post-Gd-DTPA T1- and T2-weighted images. Results to date (over 40 cases) suggest that this technique will be extremely helpful