Steroid receptor coupling becomes nuclear.

PubMed

Galigniana, Mario D

2012-06-22

In this issue of Chemistry & Biology, Grossman et al. report a study on aldosterone-dependent nuclear translocation of the mineralocorticoid receptor (MR). They analyze the dependency of MR retrotransport, DNA-binding, and transcriptional activity on Hsp90 and demonstrate that MR dimerization is a nuclear event. Copyright © 2012 Elsevier Ltd. All rights reserved.

Varying levels of small microcalcifications and macrophages in ATTR and AL cardiac amyloidosis: implications for utilizing nuclear medicine studies to subtype amyloidosis.

PubMed

Stats, Miriam A; Stone, James R

2016-01-01

Recently, there has been much interest in using nuclear medicine studies to noninvasively identify and subtype cardiac amyloidosis. In particular, modified bone scans using (99m)Tc-3,3-diphosphono-1,2-propanodicarboxylic acid ((99m)Tc-DPD) and (99m)Tc-pyrophosphate ((99m)Tc-PYP) are being used to selectively identify patients with ATTR amyloidosis rather than AL amyloidosis. The morphologic basis underlying the selectivity of these imaging modalities for ATTR amyloidosis has been unclear. To determine if variations in microcalcifications and/or macrophages within ATTR and AL amyloidosis might be responsible for the selectivity for these imaging modalities, 8 endomyocardial biopsies of ATTR amyloidosis and 7 endomyocardial biopsies of AL amyloidosis were stained with von Kossa calcium stains and with immunohistochemistry for the macrophage marker CD68. Compared with AL amyloidosis, there was a greater density of small microcalcifications in cases of ATTR amyloidosis (mean=16.8 vs. 6.5 per 200× field, P=.008). In contrast, there were fewer macrophages in ATTR amyloidosis compared with AL amyloidosis (mean=2.5 vs. 11.7 per 200× field, P=.0004). The density of microcalcifications within each group was not related to patient age, echocardiographic features of cardiac function, or serum levels of calcium and creatinine. These data suggest that microcalcifications but not macrophages likely underlie the selectivity of modified bone scans for ATTR amyloidosis and suggest that other pathologic entities containing microcalcifications might also result in positive scans with these imaging modalities. Copyright © 2016 Elsevier Inc. All rights reserved.

Intrasite motions and monument instabilities at Medicina ITRF co-location site

NASA Astrophysics Data System (ADS)

Sarti, Pierguido; Abbondanza, Claudio; Legrand, Juliette; Bruyninx, Carine; Vittuari, Luca; Ray, Jim

2013-03-01

We process the total-station surveys performed at the ITRF co-location site Medicina (Northern Italy) over the decade (2001-2010) with the purpose of determining the extent of local intrasite motions and relating them to local geophysical processes, the geological setting and the design of the ground pillars. In addition, continuous observations acquired by two co-located GPS stations (MEDI and MSEL separated by ≈27 m) are analysed and their relative motion is cross-checked with the total-station results. The local ground control network extends over a small area (<100 × 100 m) but the results demonstrate significant anisotropic deformations with rates up to 1.6 mm a-1, primarily horizontal, a value comparable to intraplate tectonic deformations. The results derived from GPS and total-station observations are consistent and point to the presence of horizontal intrasite motions over very short distances possibly associated with varying environmental conditions in a very unfavourable local geological setting and unsuitable monument design, these latter being crucial aspects of the realization and maintenance of global permanent geodetic networks and the global terrestrial reference frame.

A radioluminescent nuclear battery using volumetric configuration: 63Ni solution/ZnS:Cu,Al/InGaP.

PubMed

Russo, Johnny; Litz, Marc; Ray, William; Smith, Brenda; Moyers, Richard

2017-12-01

Energy dense power sources are critical to the development of compact, remote sensors for terrestrial and space applications. Nuclear batteries using β - -emitting radioisotopes possess energy densities 1000 times greater than chemical batteries. Their power generation is a function of β - flux saturation point relative to the planar (2D) configuration, β - range, and semiconductor converter. An approach to increase power density in a beta-photovoltaic (β-PV) nuclear battery is described. By using volumetric (3D) configuration, the radioisotope, nickel-63 ( 63 Ni) in a chloride solution was integrated in a phosphor film (ZnS:Cu,Al) where the β - energy is converted into optical energy. The optical energy was converted to electrical energy via an indium gallium phosphate (InGaP) photovoltaic (PV) cell, which was optimized for low light illumination and closely matched to radioluminescence (RL) spectrum. With 15mCi of 63 Ni activity, the 3D configuration energy values surpassed 2D configuration results. The highest total power conversion efficiency (η t ) of 3D configuration was 0.289% at 200µm compared 0.0638% for 2D configuration at 50µm. The highest electrical power and η t for the 3D configuration were 3.35 nW e /cm 2 at an activity of 30mCi and 0.289% at an activity of 15mCi, respectively. By using 3D configuration, the interaction space between the radioisotope source and scintillation material increased, allowing for significant electrical energy output, relative to the 2D configuration. These initial results represent a first step to increase nuclear battery power density from microwatts to milliwatts per 1000cm 3 with the implementation of higher energy β - sources. Published by Elsevier Ltd.

Decoherence and fluctuation dynamics of the quantum dot nuclear spin bath probed by nuclear magnetic resonance

NASA Astrophysics Data System (ADS)

Chekhovich, Evgeny A.

2017-06-01

Dynamics of nuclear spin decoherence and nuclear spin flip-flops in self-assembled InGaAs/GaAs quantum dots are studied experimentally using optically detected nuclear magnetic resonance (NMR). Nuclear spin-echo decay times are found to be in the range 1-4 ms. This is a factor of ~3 longer than in strain-free GaAs/AlGaAs structures and is shown to result from strain-induced quadrupolar effects that suppress nuclear spin flip-flops. The correlation times of the flip-flops are examined using a novel frequency-comb NMR technique and are found to exceed 1 s, a factor of ~1000 longer than in strain-free structures. These findings complement recent studies of electron spin coherence and reveal the paradoxical dual role of the quadrupolar effects in self-assembled quantum dots: large increase of the nuclear spin bath coherence and at the same time significant reduction of the electron spin-qubit coherence. Approaches to increasing electron spin coherence are discussed. In particular the nanohole filled GaAs/AlGaAs quantum dots are an attractive option: while their optical quality matches the self-assembled dots the quadrupolar effects measured in NMR spectra are a factor of 1000 smaller.

[Physical activity centre VSTJ MEDICINA Prague--rehabilitation for diabetics].

PubMed

Fábin, P; Matoulek, M

2007-05-01

Physical activity is the basic non-pharmacological instrument in the treatment of type 2 diabetes. Nevertheless, only a small number of diabetics take regular physical exercise. One of the reasons why diabetics "do not exercise" is that they have little opportunity to try physical stress under expert supervision and to get to know its effects on, for example, sugar levels. It is a very complex matter to define the optimal intensity of physical activity of, for example, a diabetic who suffers from obesity. In 2001 VSTJ MEDICINA Prague opened its first physical activity centre at the First Faculty of Medicine, Charles University in Prague, in cooperation with the Third Internal Clinic and the Institute of Sports Medicine of the First Faculty of Medicine, Charles University in Prague. It now has over 2000 members, of whom around 60% are patients with metabolic syndrome. Over 150 patients exercise every day under the supervision of expert instructors. The main objective of the Physical Activity Centre is to teach patients the correct principles of physical exercise to enable them to continue carrying out their trainers' instructions at home. A correct understanding of the importance of physical exercise and practical experience under the supervision of experienced instructors improves compliance and has a strong effect on the compensation of diabetes, thereby improving the prognoses of these patients.

26Al production: The Allende meteorite (Chihuahua) stellar nucleosynthesis and solar models

NASA Astrophysics Data System (ADS)

Araujo-Escalona, V.; Andrade, E.; Barrón-Palos, L.; Canto, C.; Favela, F.; Huerta, A.; de Lucio, O.; Ortiz, M. E.; Solís, C.; Chávez, E.

2015-07-01

In 1969 a meteorite fell near the small town of Allende, state of Chihuahua in the north of Mexico. Its study yielded information that changed the current understanding of the solar model. In particular traces of 26Al were found. Abundances of that isotope had been seen in the universe and were related to regions of active heavy nucleosynthesis. Its presence on the solar system was unexpected. It is now understood that cosmic rays induce nuclear reactions on materials to produce 26Al, on Earth this is well known and it is the basis of many environmental studies, so it is not only the product of some high metalicity star collapse. Taking advantage of the recently reinforced laboratory infrastructure of the Instituto de Física, at UNAM in Mexico City, we proposed to measure the cross section for 26Al production via some of the most likely reactions, from the nuclear physics point of view (highest Q-values). In this paper the study of the 28Si(d,α)26 Al nuclear reaction is shown. A target is prepared by a mixture of silicon and aluminum powders. It is irradiated with a deuteron beam (≈1 µA current) at the MV CN-Van de Graaff accelerator laboratory. The number of projectiles is deduced by Rutherford Backscattering Spectrometry (RBS). The produced 26Al nuclei are then counted at the Accelerator Mass Spectrometry Laboratory.

27Al, 63Cu NMR spectroscopy and electrical transport in Heusler Cu-Mn-Al alloy powders

NASA Astrophysics Data System (ADS)

Nadutov, V. M.; Perekos, A. O.; Kokorin, V. V.; Trachevskii, V. V.; Konoplyuk, S. M.; Vashchuk, D. L.

2018-02-01

The ultrafine powder of the Heusler Cu-13,1Mn-12,6Al (wt.%) alloy produced by electrical spark dispersion (ESD) in ethanol and the pellets prepared by pressing of the powders and aged in various gas environment (air, Ar, vacuum) were studied by XRD, nuclear magnetic resonance, magnetic and electric transport methods. The constituent phases were identified as b.c.c. α-Cu-Mn-Al, f.c.c. γ-Cu-Mn-Al, Cu2MnAl, and oxides. The sizes of the coherently scattering domains (CSD) and the saturation magnetizations were in the range of 4-90 nm and 0-1.5 Am2/kg, respectively. 27Al and 63Cu NMR spectra of the powders and pellets have shown hyperfine structure caused by contributions from atomic nuclei of the constituent phases. The aging of pellets in different gas environments had effect on their phase composition but no effect on dispersion of the phases. In contrast to the as-cast alloy, electrical resistance of the pellets evidenced semiconducting behavior at elevated temperatures due to the presence of metal oxides formed on the surfaces of nanoparticles.

Ion irradiation testing and characterization of FeCrAl candidate alloys

DOE Office of Scientific and Technical Information (OSTI.GOV)

Anderoglu, Osman; Aydogan, Eda; Maloy, Stuart Andrew

2014-10-29

The Fuel Cycle Research and Development program’s Advanced Fuels Campaign has initiated a multifold effort aimed at facilitating development of accident tolerant fuels. This effort involves development of fuel cladding materials that will be resistant to oxidizing environments for extended period of time such as loss of coolant accident. Ferritic FeCrAl alloys are among the promising candidates due to formation of a stable Al₂O₃ oxide scale. In addition to being oxidation resistant, these promising alloys need to be radiation tolerant under LWR conditions (maximum dose of 10-15 dpa at 250 – 350°C). Thus, in addition to a number of commerciallymore » available alloys, nuclear grade FeCrAl alloys developed at ORNL were tested using high energy proton irradiations and subsequent characterization of irradiation hardening and damage microstructure. This report summarizes ion irradiation testing and characterization of three nuclear grade FeCrAl cladding materials developed at ORNL and four commercially available Kanthal series FeCrAl alloys in FY14 toward satisfying FCRD campaign goals.« less

[Profile of patients with anophthalmic cavity: study at Faculdade de Medicina de Botucatu - UNESP].

PubMed

Narikawa, Silvia; Natsuaki, Kryscia Leiko; Fruet, Juliana; Padovani, Carlos Roberto; Schellini, Silvana Artioli

2011-01-01

To evaluate the profile of anophthalmic cavity carriers and patients' evolution with the employed treatments. Retrospective study carried out at Faculdade de Medicina de Botucatu, to evaluate the profile and the evolution of patients with anophthalmic cavity treated in our service. Data were evaluated according to the frequency of occurrence and analysis of association. Anophthalmic cavity was more frequently observed in young males, workers in activities carried on with their hands. Trauma and phthisis bulbi were the most frequent causes, with differences according to age and gender. The complications were high (57.1% of cases), the majority occurred belatedly. Trauma is still an important cause of loss of the eye. The complications during the follow-up of the patient are frequent, occurring in general, very late, which reinforces the need for periodic and prolonged monitoring of patients with anophthalmic cavity.

Using SAFRAN Software to Assess Radiological Hazards from Dismantling of Tammuz-2 Reactor Core at Al-tuwaitha Nuclear Site

NASA Astrophysics Data System (ADS)

Abed Gatea, Mezher; Ahmed, Anwar A.; jundee kadhum, Saad; Ali, Hasan Mohammed; Hussein Muheisn, Abbas

2018-05-01

The Safety Assessment Framework (SAFRAN) software has implemented here for radiological safety analysis; to verify that the dose acceptance criteria and safety goals are met with a high degree of confidence for dismantling of Tammuz-2 reactor core at Al-tuwaitha nuclear site. The activities characterizing, dismantling and packaging were practiced to manage the generated radioactive waste. Dose to the worker was considered an endpoint-scenario while dose to the public has neglected due to that Tammuz-2 facility is located in a restricted zone and 30m berm surrounded Al-tuwaitha site. Safety assessment for dismantling worker endpoint-scenario based on maximum external dose at component position level in the reactor pool and internal dose via airborne activity while, for characterizing and packaging worker endpoints scenarios have been done via external dose only because no evidence for airborne radioactivity hazards outside the reactor pool. The in-situ measurements approved that reactor core components are radiologically activated by Co-60 radioisotope. SAFRAN results showed that the maximum received dose for workers are (1.85, 0.64 and 1.3mSv/y) for activities dismantling, characterizing and packaging of reactor core components respectively. Hence, the radiological hazards remain below the low level hazard and within the acceptable annual dose for workers in radiation field

"De medicina et morbis" from De rerum naturis by Rabano Mauro.

PubMed

Iorio, Luigi; Mantella, Daniela; Iorio, Brunella

2009-01-01

De rerum naturis from the Monastery of Montecassino (MS codex 132) by Rabano Mauro, is a medieval encyclopedia issued around the year 1025, in the Abbey of Montecassino, during the period of Abbot Teobaldo. It is a copy of a more ancient text, written almost certainly in the Abbey of Fulda 2 centuries before, when Rabano Mauro was the abbot - that is, in the Carolingian age. In the Book 18 there is a chapter entitled "De medicina et morbis," in which we find related the fundamental principles on which studies of the human body, illness and the principal medicinal herbs were based. The text is not intended for teaching the medical art, but has the precise objective of helping to form the cultured Christian, trying to combine the old Greek-Roman tradition with a mystical vision, giving a moral application according to the dictates of Jewish-Christian religion. This text is indicative of the fusion of the scientific and religious worlds in the West during the Middle Ages. This interpretation of the universe will last for about a millennium, and only the Renaissance will be able to separate the 2 worlds again.

Incommensurate to commensurate antiferromagnetism in CeRhAl 4 Si 2 : An Al 27 NMR study

DOE PAGES

Sakai, Hironori; Hattori, T.; Tokunaga, Y.; ...

2016-01-04

27Al nuclear magnetic resonance (NMR) experiments have been performed on a single crystal of CeRhAl 4Si 2, which is an antiferromagnetic Kondo-lattice compound with successive antiferromagnetic transitions of T N1 = 14 K and T N2 = 9 K at zero external field. In the paramagnetic state, the Knight shifts, quadrupolar frequency, and asymmetric parameter of electrical field gradient on the Al sites have been determined, which have local orthorhombic symmetry. The transferred hyperfine coupling constants are also determined. Here, analysis of the NMR spectra indicates that a commensurate antiferromagnetic structure exists below T N2, but an incommensurate modulation ofmore » antiferromagnetic moments is present in the antiferromagnetic state between T N1 and T N2. The spin-lattice relaxation rate suggests that the 4f electrons behave as local moments at temperatures above T N1.« less

MgCoAl and NiCoAl LDHs synthesized by the hydrothermal urea hydrolysis method: Structural characterization and thermal decomposition

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chagas, L.H., E-mail: lhchagas-prometro@inmetro.gov.br; Instituto Nacional de Metrologia Qualidade e Tecnologia, Divisão de Metrologia de Materiais, 25250-020 Duque de Caxias, RJ; De Carvalho, G.S.G.

Highlights: • We synthesized MgCoAl and NiCoAl LDHs by the urea hydrolysis method. • Aluminum rich and crystalline materials have been formed. • The calcination of the LDHs generated mixed oxides with high surface areas. - Abstract: Layered double hydroxides (LDHs) with Mg/Co/Al and Ni/Co/Al were synthesized for the first time by the urea hydrolysis method. The experimental conditions promoted aluminum rich and crystalline materials. The formation of LDHs was investigated by powder X-ray diffraction (XRD), chemical analysis, solid state nuclear magnetic resonance with magic angle spinning ({sup 27}Al-MAS-NMR), simultaneous thermogravimetric/differential thermal analysis (TGA/DTA), FTIR spectroscopy, scanning electron microscopy (SEM),more » and N{sub 2} adsorption–desorption experiments. A single phase corresponding to LDH could be obtained in all the investigated compositions. Thermal calcination of these LDHs at 500 °C resulted in the formation of solid solutions in which Al{sup 3+} was dissolved. All the calcined materials have rock-salt like structures and high surface areas.« less

{sup 26}Al production: The Allende meteorite (Chihuahua) stellar nucleosynthesis and solar models

DOE Office of Scientific and Technical Information (OSTI.GOV)

Araujo-Escalona, V.; Andrade, E.; Barrón-Palos, L.

2015-07-23

In 1969 a meteorite fell near the small town of Allende, state of Chihuahua in the north of Mexico. Its study yielded information that changed the current understanding of the solar model. In particular traces of {sup 26}Al were found. Abundances of that isotope had been seen in the universe and were related to regions of active heavy nucleosynthesis. Its presence on the solar system was unexpected. It is now understood that cosmic rays induce nuclear reactions on materials to produce {sup 26}Al, on Earth this is well known and it is the basis of many environmental studies, so itmore » is not only the product of some high metalicity star collapse. Taking advantage of the recently reinforced laboratory infrastructure of the Instituto de Física, at UNAM in Mexico City, we proposed to measure the cross section for {sup 26}Al production via some of the most likely reactions, from the nuclear physics point of view (highest Q-values). In this paper the study of the {sup 28}Si(d,α){sup 26} Al nuclear reaction is shown. A target is prepared by a mixture of silicon and aluminum powders. It is irradiated with a deuteron beam (≈1 µA current) at the MV CN-Van de Graaff accelerator laboratory. The number of projectiles is deduced by Rutherford Backscattering Spectrometry (RBS). The produced {sup 26}Al nuclei are then counted at the Accelerator Mass Spectrometry Laboratory.« less

[Positivism and medical science in Rio Grande do Sul: the Faculdade de Medicina de Porto Alegre].

PubMed

Weber, B T

1998-01-01

The article analyzes conflicts and interests at one of Rio Grande de Sul's main centers for medical science, the Faculdade de Medicina de Porto Alegre. It explores the meaning and impact of the emergence of this specific, exclusive field of knowledge in a state where positivist principles of professional freedom were adopted by successive administrations during the early period of the Republic. Physicians there launched an entrenched war to uphold the principles of science over faith and politics, challenging the positivism of the party which held power in Rio Grande do Sul throughout the years. This perspective grew and developed in a climate of conflict and doubts among physicians, within a political context that differed from the rest of Brazil.

Developments of FPGA-based digital back-ends for low frequency antenna arrays at Medicina radio telescopes

NASA Astrophysics Data System (ADS)

Naldi, G.; Bartolini, M.; Mattana, A.; Pupillo, G.; Hickish, J.; Foster, G.; Bianchi, G.; Lingua, A.; Monari, J.; Montebugnoli, S.; Perini, F.; Rusticelli, S.; Schiaffino, M.; Virone, G.; Zarb Adami, K.

In radio astronomy Field Programmable Gate Array (FPGA) technology is largely used for the implementation of digital signal processing techniques applied to antenna arrays. This is mainly due to the good trade-off among computing resources, power consumption and cost offered by FPGA chip compared to other technologies like ASIC, GPU and CPU. In the last years several digital backend systems based on such devices have been developed at the Medicina radio astronomical station (INAF-IRA, Bologna, Italy). Instruments like FX correlator, direct imager, beamformer, multi-beam system have been successfully designed and realized on CASPER (Collaboration for Astronomy Signal Processing and Electronics Research, https://casper.berkeley.edu) processing boards. In this paper we present the gained experience in this kind of applications.

NQRS Data for AlDO28Si13 (Subst. No. 0033)

NASA Astrophysics Data System (ADS)

Chihara, H.; Nakamura, N.

This document is part of Subvolume A `Substances Containing Ag … C10H15' of Volume 48 `Nuclear Quadrupole Resonance Spectroscopy Data' of Landolt-Börnstein - Group III `Condensed Matter'. It contains an extract of Section `3.2 Data tables' of the Chapter `3 Nuclear quadrupole resonance data' providing the NQRS data for AlDO28Si13 (Subst. No. 0033)

NQRS Data for AlDO70Si34 (Subst. No. 0035)

NASA Astrophysics Data System (ADS)

Chihara, H.; Nakamura, N.

This document is part of Subvolume A `Substances Containing Ag … C10H15' of Volume 48 `Nuclear Quadrupole Resonance Spectroscopy Data' of Landolt-Börnstein - Group III `Condensed Matter'. It contains an extract of Section `3.2 Data tables' of the Chapter `3 Nuclear quadrupole resonance data' providing the NQRS data for AlDO70Si34 (Subst. No. 0035)

NQRS Data for AlDO28Si13 (Subst. No. 0034)

NASA Astrophysics Data System (ADS)

Chihara, H.; Nakamura, N.

This document is part of Subvolume A `Substances Containing Ag … C10H15' of Volume 48 `Nuclear Quadrupole Resonance Spectroscopy Data' of Landolt-Börnstein - Group III `Condensed Matter'. It contains an extract of Section `3.2 Data tables' of the Chapter `3 Nuclear quadrupole resonance data' providing the NQRS data for AlDO28Si13 (Subst. No. 0034)

A nuclear fragmentation energy deposition model

NASA Technical Reports Server (NTRS)

Ngo, D. M.; Wilson, J. W.; Fogarty, T. N.; Buck, W. W.; Townsend, L. W. (Principal Investigator)

1991-01-01

A formalism for target fragment transport is presented with application to energy loss spectra in thin silicon devices. A nuclear data base is recommended that agrees well with the measurements of McNulty et al. using surface barrier detectors. High-energy events observed by McNulty et al., which are not predicted by intranuclear cascade models, are well represented by the present work.

Prediction of Nuclear Masses as a function of P and F-spin

NASA Astrophysics Data System (ADS)

Teymurazyan, Artur; Aprahamian, Ani; Georgieva, Ana

2001-10-01

Nuclear masses are one of the most important components in nucleosynthesis calculations of elemental abundances for specific stellar scenarios. Proton rich nuclei in the A=80 region are thought to be produced in the rp-process (rapid p and α-capture)involving a large number of unknown nuclei. Schatz et al.(H. Schatz et al., Phys. Rep. 294,167 (1998)) have carried out an extensive comparison of the effects on abundances that result from the use of different mass models. One of these models was a semi-empirical mass model(A. Aprahamian et al., Rev. Mex. Fis. 42, 1 (1996)) based on the relationship of the nuclear structure component of the nuclear mass on the parameter P=N_pN_n/(N_p+N_n) where N-p and Nn are the number of valence protons and neutrons. Davis et al.(E.D. Davis et al., Phys. Rev. C 44, 1655 (1991)) had used another approach involving F-spin (an approximate symmetry under particle-hole Conjugation) to predict binding energies for r-process nuclei in the Z=50-82 and N=82-126 region. In this paper, we combine structure systematics using F-spin(A. Georgieva et al., Int. J. Theor. Phys. 28, 769 (1989)) to show a simple relationship between P and F-spin for this very interesting region and to apply it to the prediction of nuclear masses in the A=80 region of nuclei.

Results and Outlook of The Aluminum Capture Experiment (AlCap)

NASA Astrophysics Data System (ADS)

Quirk, John R.; Miller, James; ALCap Collaboration Collaboration

2016-03-01

Observation of neutrinoless muon-to-electron conversion in the presence of a nucleus would be unambiguous evidence of physics Beyond the Standard Model. Two experiments, COMET at J-PARC and Mu2e at Fermilab, will search for this process in the coming decade. Barring discovery, these experiments will provide upper-limits on this branching ratio up to 10,000 times better than previously published. COMET/Mu2e developed a joint venture, the AlCap Experiment, to measure particle emission spectra from muonic interactions in a number of materials. As a major source of background hits in COMET/Mu2e detectors, AlCap sought to measure the charged particle and neutron spectra following nuclear capture on the candidate target materials aluminum and titanium. Additionally, COMET/Mu2e are exploring normalization schemes via AlCap's measurement of the photon spectra following both atomic and nuclear capture. Over the course of 2013 and 2015, AlCap performed three runs at the Paul Scherrer Institut in Switzerland. The first acquired preliminary data for all spectra, the second run collected only neutron and photon data, and the third primarily charged particle data. Preliminary analyses of the first two runs, already impactful for COMET/Mu2e, is presented along with a summary of the third.

Antisense Proline-Arginine RAN dipeptides linked to C9ORF72-ALS/FTD form toxic nuclear aggregates that initiate in vitro and in vivo neuronal death

PubMed Central

Wen, Xinmei; Tan, Wenzhi; Westergard, Thomas; Krishnamurthy, Karthik; ShamamandriMarkandaiah, Shashirekha; Shi, Yingxiao; Lin, Shaoyu; Shneider, Neil A.; Monaghan, John; Pandey, Udai B.; Pasinelli, Piera; Ichida, Justin K.; Trotti, Davide

2015-01-01

SUMMARY Expanded GGGGCC nucleotide repeats within the C9ORF72 gene are the most common genetic mutation associated with both amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). Sense and antisense transcripts of these expansions are translated to form five dipeptide repeat proteins (DRPs). We employed primary cortical and motor neuron cultures, live-cell imaging, and transgenic fly models and found that the arginine-rich dipeptides, in particular Proline-Arginine (PR), are potently neurotoxic. Factors that anticipated their neurotoxicity included aggregation in nucleoli, decreased number of processing bodies, and stress granules formation, implying global translational dysregulation as path accountable for toxicity. Nuclear PR aggregates were also found in human-induced motor neurons and postmortem spinal cord tissues from C9ORF72 ALS and ALS/FTD patients. Intronic G4C2 transcripts, but not loss of C9ORF72 protein, are also toxic to motor and cortical neurons. Interestingly, G4C2 transcript-mediated neurotoxicity synergizes with that of PR aggregates, suggesting convergence of mechanisms. PMID:25521377

Paraquat adsorption on NaX and Al-MCM-41.

PubMed

Rongchapo, Wina; Deekamwong, Krittanun; Loiha, Sirinuch; Prayoonpokarach, Sanchai; Wittayakun, Jatuporn

2015-01-01

The aim of this work is to determine paraquat adsorption capacity of zeolite NaX and Al-MCM-41. All adsorbents were synthesized by hydrothermal method using rice husk silica. For Al-MCM-41, aluminum (Al) was added to the synthesis gel of MCM-41 with Al content of 10, 15, 20 and 25 wt%. The faujasite framework type of NaX and mesoporous characteristic of Al-MCM-41 were confirmed by X-ray diffraction. Surface area of all adsorbents determined by N2 adsorption-desorption analysis was higher than 650 m2/g. Al content and geometry were determined by X-ray fluorescence and 27Al nuclear magnetic resonance, respectively. Morphology of Al-MCM-41 were studied by transmission electron microscopy; macropores and defects were observed. The paraquat adsorption experiments were conducted using a concentration range of 80-720 mg/L for NaX and 80-560 mg/L for Al-MCM-41. The paraquat adsorption isotherms from all adsorbents fit well with the Langmuir model. The adsorption capacity of NaX was 120 mg/g-adsorbent. Regarding Al-MCM-41, the 10% Al-MCM-41 exhibited the lowest capacity of 52 mg/g-adsorbent while the other samples had adsorption capacity of 66 mg/g-adsorbent.

Fifty years since the nuclear accident in Palomares (Almeria). Medical repercussions.

PubMed

Laynez-Bretones, F; Lozano-Padilla, C

In January 1966, 2 US military aircraft collided over the skies of Palomares (Almeria). One of them carried thermonuclear bombs, which released plutonium and other radioactive materials upon striking the ground. The most contaminated earth and plants were immediately removed. The Indalo Project was launched to study the effects of nuclear material on the inhabitants and environment of Palomares. A total of 1,077 inhabitants have been monitored since then, and the official version is that the ionising radiation has not been related to any type of disease. However, secrecy has surrounded much of the investigations, and no trustworthy epidemiological study has been conducted in the area. Approximately 500g of plutonium and americium remains in Palomares. Although the risk for the population appears to be low, this radioactive material should be removed as soon as possible. Copyright © 2017 Elsevier España, S.L.U. and Sociedad Española de Medicina Interna (SEMI). All rights reserved.

Nuclear Receptors in Neurodegenerative Diseases

PubMed Central

Skerrett, Rebecca; Malm, Tarja; Landreth, Gary

2014-01-01

Nuclear receptors have generated substantial interest in the past decade as potential therapeutic targets for the treatment of neurodegenerative disorders. Despite years of effort, effective treatments for progressive neurodegenerative diseases such as Alzheimer’s disease, Parkinson’s disease, Huntington’s disease and ALS remain elusive, making non-classical drug targets such as nuclear receptors an attractive alternative. A substantial literature in mouse models of disease and several clinical trials have investigated the role of nuclear receptors in various neurodegenerative disorders, most prominently AD. These studies have met with mixed results, yet the majority of studies in mouse models report positive outcomes. The mechanisms by which nuclear receptor agonists affect disease pathology remain unclear. Deciphering the complex signaling underlying nuclear receptor action in neurodegenerative diseases is essential for understanding this variability in preclinical studies, and for the successful translation of nuclear receptor agonists into clinical therapies. PMID:24874548

2001 GPS and Classical Survey at Medicina Observatory: Local Tie and VLBI Antenna's Reference Point Determination

NASA Astrophysics Data System (ADS)

Vittuari, Luca; Sarti, Pierguido; Tomasi, Paolo

2001-12-01

During a 6 days campaign in June 2001, we have performed a local survey at Medicina Observatory using classical geodesy and GPS techniques in order to determine the effects of an undergone track repair. We have determined the position of the reference point P within a local and ITRF2000 (epoch 1997.0) reference frames using trilateration and triangulation: Pclas_{loc}^{2001}=(21.580pm0.001,45.536pm0.001,17.699pm0.001) Pclas_{loc}^{2001}=(21.580pm0.001,45.536pm0.001,17.699pm0.001) Pclas_{ITRF2000}^{1997.0}=(4461369.982pm0.001,919596.818pm0.001,4449559.207pm0.001) Kinematic GPS has also given interesting results:Medicina in ITRF2000 the agreement is striking especially for the classical technique. A complete tie between the 3-D forced centered local ground control network (materialised in May 2000) and the widely used older network (which is now experiencing some problems due to the disgregation of the concrete where bolts are situated) has also been realised. This will allow inter-comparison of results obtained by the different campaigns that have been carried out in the last decade. Finally, the position of the ASI-GPS permanent station has been estimated within the local ground control network. Thus, using classical methodology, a precise determination of the VLBI-GPS ex-centre vector has been possible.

Nuclear Data Sheets for A=40

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, Jun

The experimental nuclear structure data and decay data are evaluated for the known nuclides of mass 40 (Mg, Al, Si, P, S, Cl, Ar, K, Ca, Sc, Ti). Detailed evaluated nuclear structure information is presented with the best values recommended for level energies, half-lives, γ-ray energies and intensities, decay properties (energies, intensities and placement of radiations), and other spectroscopic data. The {sup 40}Ca and {sup 40}K nuclides remain as the most extensively studied from many different reactions and decays; no excited states are known in {sup 40}Mg, {sup 40}Al, {sup 40}P and {sup 40}Ti. This work supersedes the earlier fullmore » evaluation of A=40 by J. Cameron and B. Singh (2004Ca38).« less

Liver X Receptor Genes Variants Modulate ALS Phenotype.

PubMed

Mouzat, Kevin; Molinari, Nicolas; Kantar, Jovana; Polge, Anne; Corcia, Philippe; Couratier, Philippe; Clavelou, Pierre; Juntas-Morales, Raul; Pageot, Nicolas; Lobaccaro, Jean -Marc A; Raoul, Cedric; Lumbroso, Serge; Camu, William

2018-03-01

Amyotrophic lateral sclerosis (ALS) is one of the most severe motor neuron (MN) disorders in adults. Phenotype of ALS patients is highly variable and may be influenced by modulators of energy metabolism. Recent works have implicated the liver X receptors α and β (LXRs), either in the propagation process of ALS or in the maintenance of MN survival. LXRs are nuclear receptors activated by oxysterols, modulating cholesterol levels, a suspected modulator of ALS severity. In a cohort of 438 ALS patients and 330 healthy controls, the influence of LXR genes on ALS risk and phenotype was studied using single nucleotide polymorphisms (SNPs). The two LXRα SNPs rs2279238 and rs7120118 were shown to be associated with age at onset in ALS patients. Consistently, homozygotes were twice more correlated than were heterozygotes to delayed onset. The onset was thus delayed by 3.9 years for rs2279238 C/T carriers and 7.8 years for T/T carriers. Similar results were obtained for rs7120118 (+2.1 years and +6.7 years for T/C and C/C genotypes, respectively). The LXRβ SNP rs2695121 was also shown to be associated with a 30% increase of ALS duration (p = 0.0055, FDR = 0.044). The tested genotypes were not associated with ALS risk. These findings add further evidence to the suspected implication of LXR genes in the disease process of ALS and might open new perspectives in ALS therapeutics.

Direct current superconducting quantum interference device spectrometer for pulsed nuclear magnetic resonance and nuclear quadrupole resonance at frequencies up to 5 MHz

DOE Office of Scientific and Technical Information (OSTI.GOV)

TonThat, D.M.; Clarke, J.

1996-08-01

A spectrometer based on a dc superconducting quantum interference device (SQUID) has been developed for the direct detection of nuclear magnetic resonance (NMR) or nuclear quadrupole resonance (NQR) at frequencies up to 5 MHz. The sample is coupled to the input coil of the niobium-based SQUID via a nonresonant superconducting circuit. The flux locked loop involves the direct offset integration technique with additional positive feedback in which the output of the SQUID is coupled directly to a low-noise preamplifier. Precession of the nuclear quadrupole spins is induced by a magnetic field pulse with the feedback circuit disabled; subsequently, flux lockedmore » operation is restored and the SQUID amplifies the signal produced by the nuclear free induction signal. The spectrometer has been used to detect {sup 27}Al NQR signals in ruby (Al{sub 2}O{sub 3}[Cr{sup 3+}]) at 359 and 714 kHz. {copyright} {ital 1996 American Institute of Physics.}« less

Active nuclear import and passive nuclear export are the primary determinants of TDP-43 localization.

PubMed

Pinarbasi, Emile S; Cağatay, Tolga; Fung, Ho Yee Joyce; Li, Ying C; Chook, Yuh Min; Thomas, Philip J

2018-05-04

ALS (Amyotrophic Lateral Sclerosis) is a neurodegenerative disease characterized by the redistribution of the RNA binding protein TDP-43 in affected neurons: from predominantly nuclear to aggregated in the cytosol. However, the determinants of TDP-43 localization and the cellular insults that promote redistribution are incompletely understood. Here, we show that the putative Nuclear Export Signal (NES) is not required for nuclear egress of TDP-43. Moreover, when the TDP-43 domain which contains the putative NES is fused to a reporter protein, YFP, the presence of the NES is not sufficient to mediate nuclear exclusion of the fusion protein. We find that the previously studied "∆NES" mutant, in which conserved hydrophobic residues are mutated to alanines, disrupts both solubility and splicing function. We further show that nuclear export of TDP-43 is independent of the exportin XPO1. Finally, we provide evidence that nuclear egress of TDP-43 is size dependent; nuclear export of dTomato TDP-43 is significantly impaired compared to Flag TDP-43. Together, these results suggest nuclear export of TDP-43 is predominantly driven by passive diffusion.

Integrated Response Time Evaluation Methodology for the Nuclear Safety Instrumentation System

NASA Astrophysics Data System (ADS)

Lee, Chang Jae; Yun, Jae Hee

2017-06-01

Safety analysis for a nuclear power plant establishes not only an analytical limit (AL) in terms of a measured or calculated variable but also an analytical response time (ART) required to complete protective action after the AL is reached. If the two constraints are met, the safety limit selected to maintain the integrity of physical barriers used for preventing uncontrolled radioactivity release will not be exceeded during anticipated operational occurrences and postulated accidents. Setpoint determination methodologies have actively been developed to ensure that the protective action is initiated before the process conditions reach the AL. However, regarding the ART for a nuclear safety instrumentation system, an integrated evaluation methodology considering the whole design process has not been systematically studied. In order to assure the safety of nuclear power plants, this paper proposes a systematic and integrated response time evaluation methodology that covers safety analyses, system designs, response time analyses, and response time tests. This methodology is applied to safety instrumentation systems for the advanced power reactor 1400 and the optimized power reactor 1000 nuclear power plants in South Korea. The quantitative evaluation results are provided herein. The evaluation results using the proposed methodology demonstrate that the nuclear safety instrumentation systems fully satisfy corresponding requirements of the ART.

Radiation characteristics of Al wire arrays on Z*

NASA Astrophysics Data System (ADS)

Coverdale, C. A.; Ampleford, D. J.; Jones, B.; Cuneo, M. E.; Hansen, S.; Jennings, C. A.; Moore, N.; Jones, S. C.; Deeney, C.

2011-10-01

Analysis of mixed material nested wire array experiments at Z have shown that the inner wire array dominates the hottest regions of the stagnated z pinch. In those experiments, substantial free-bound continuum radiation was observed when Al was fielded on the inner wire array. Experiments with Al (5% Mg) on both wire arrays have also been fielded, with variations in the free-bound continuum observed. These variations appear to be tied to the initial mass and diameter of the wire array. The results presented here will investigate the trends in the measured emission (Al and Mg K-shell and free-bound continuum) and will compare the measured output to more recent Al wire array experimental results on the refurbished Z accelerator. *Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000. +current address: NNSA/DOE Headquarters, Washington D.C.

Precision Half-life Measurement of 25Al

NASA Astrophysics Data System (ADS)

Long, Jacob; Ahn, Tan; Allen, Jacob; Bardayan, Daniel; Becchetti, Fredrich; Blankstein, Drew; Brodeur, Maxime; Burdette, Daniel; Frentz, Bryce; Hall, Matthew; Kelly, James; Kolata, James; O'Malley, Patrick; Schultz, Bradley; Strauss, Sabrina; Valverde, Adrian; TwinSol Collaboration

2017-09-01

In recent years, precision measurements have led to considerable advances in several areas of physics, including fundamental symmetry. Precise determination of ft values for superallowed mixed transitions between mirror nuclides could provide an avenue to test the theoretical corrections used to extract the Vud matrix element from superallowed pure Fermi transitions. Calculation of the ft value requires the half-life, branching ratio, and Q value. 25Al decay is of particular interest as its half-life is derived from a series of conflicting measurements, and the largest uncertainty on the ft value stems from the half-life uncertainty. The life-time was determined by the β counting of implanted 25Al on a Ta foil that was removed from the beam for counting. The 25Al beam was produced by a transfer reaction and separated by the TwinSol facility of the Nuclear Science Laboratory of the University of Notre Dame. The 25Al results will be presented with preliminary results of more recent half-life measurements. The National Science Foundation.

Securing Nuclear and Radiological Material in the Homeland

DTIC Science & Technology

2007-03-01

Gorge in order to continue efforts to produce anthrax bacteria, ricin, and botulinum toxin. 3- Jan -05 French Government “Al-Qaeda Made Biological...claim that the amount of uranium was insufficient for the construction of a nuclear device. 25- Jan -04 German government Craig Whitlock, “Germnay...Mass Destruction and Al- Qa’ida,” Al- Akhbar (Cairo),18 January 2004. 1/23/2004 Chemical U.S. forces found 3kg of cyanide at the Baghdad house of

ESR Detection of optical dynamic nuclear polarization in GaAs/Al{sub x}Ga{sub 1-x}As quantum wells at unity filling factor in the quantum Hall effect

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vitkalov, Sergey A.; Bowers, C. Russell; Simmons, Jerry A.

2000-02-15

This paper presents a study of the enhancement of the Zeeman energy of two-dimensional (2D) conduction electrons near the {nu}=1 filling factor of the quantum Hall effect by optical dynamic nuclear polarization. The change in the Zeeman energy is determined from the Overhauser shift of the transport detected electron spin resonance in GaAs/Al{sub x}Ga{sub 1-x}As multiquantum wells. In a separate experiment the NMR signal enhancement factor is obtained by radio frequency detected nuclear magnetic resonance under similar conditions in the same sample. These measurements afford an estimation of the hyperfine coupling constant between the nuclei and 2D conduction electrons. (c)more » 2000 The American Physical Society.« less

Effect of Al and Cr Content on Air and Steam Oxidation of FeCrAl Alloys and Commercial APMT Alloy

DOE PAGES

Unocic, Kinga A.; Yamamoto, Yukinori; Pint, Bruce A.

2017-03-09

To develop the next generation of accident-tolerant fuel cladding for light-water nuclear reactors, wrought FeCrAlY alloys with varying amounts of Cr and Al and commercial Kanthal APMT alloy were evaluated for short-term (4 h) oxidation resistance in steam and air at 1200–1475 °C. Model alloys with lower Cr contents and higher Al contents were evaluated in this paper as lower Cr contents are desirable for radiation damage resistance during operation. As expected, a synergistic effect was found between the Cr and Al contents to enable protective Al 2O 3 formation under these conditions. Characterization of the alumina scales formed inmore » steam found that the scale morphology was affected by the alloy Y content and detailed scanning transmission electron microscopy (STEM) detected Y segregation along scale grain boundaries at 1200 °C. However, after 4 h at 1475 °C, Y and Hf were not segregated to the oxide grain boundaries formed on APMT and the scale had a single layer structure. Finally, compared to oxidation in air, STEM characterization of the outer scale showed differences in the Fe and Cr distributions in steam.« less

In-plane nuclear field formation investigated in single self-assembled quantum dots

NASA Astrophysics Data System (ADS)

Yamamoto, S.; Matsusaki, R.; Kaji, R.; Adachi, S.

2018-02-01

We studied the formation mechanism of the in-plane nuclear field in single self-assembled In0.75Al0.25As /Al0.3Ga0.7As quantum dots. The Hanle curves with an anomalously large width and hysteretic behavior at the critical transverse magnetic field were observed in many single quantum dots grown in the same sample. In order to explain the anomalies in the Hanle curve indicating the formation of a large nuclear field perpendicular to the photo-injected electron spin polarization, we propose a new model based on the current phenomenological model for dynamic nuclear spin polarization. The model includes the effects of the nuclear quadrupole interaction and the sign inversion between in-plane and out-of-plane components of nuclear g factors, and the model calculations reproduce successfully the characteristics of the observed anomalies in the Hanle curves.

Separating Mass and Height Contributions in Gravity Variations at Medicina, Italy

NASA Astrophysics Data System (ADS)

Zerbini, S.; Bruni, S.; Errico, M.; Santi, E.; Wziontek, H.

2016-12-01

During 1996, at the Medicina station, a GPS and a superconducting gravimeter (SG) were installed in the framework of an experiment focused on the comparison between height and gravity variations. Absolute gravity observations are also performed twice a year and environmental parameters, among others water table levels, are recorded continuously. The station is also equipped with a second GPS system, the two antennas are very close to each other, and both are located in close proximity to the VLBI dish. Two decades of continuous height and gravity observations are now available which allow investigating both long and short period signals and the relevant correlations between the two measured quantities. Long period signatures are observed, a principal component is due to subsidence which is well known to occur in the area; however, also non-linear long-period behaviors are observed. Seasonal effects are also clearly recognizable in the time series and are mainly associated with the water table seasonal behavior. The station is characterized by clayey soil which is subject to consolidation effects when the water table lowers during the summer period. This effect is particularly recognizable in the SG data since the instrument is installed on a shallow foundation pillar which may suffer for height decreases in the order of 2,5-3 cm for water table lowering of 2 m.

Combined Radiation and Thermal Injury after Nuclear Attack

DTIC Science & Technology

1990-01-01

0T’Fit f-copy Combined Radiation and Thermal Injury 04 After Nuclear Attack , (M) William K. Becker, Teresa M. Buescher, William G. Cioffi, William F...Chicago, 1979, pp. 5-61. 4. Reiss, E., Stirman, J. A., Artz, C . P., et al. Fluid and electrolyte balance in burns. JAMA 152:1309- 1313, 1953. 5...et al. Septicemia in burn injury. J Trauma 1:22-31,1961. 7. Moncrief , J. A., Lindberg, R. B., Switzer, W. E., et al. Use of topical antibacterial

Nuclear fragmentation studies for microelectronic application

NASA Technical Reports Server (NTRS)

Ngo, Duc M.; Wilson, John W.; Buck, Warren W.; Fogarty, Thomas N.

1989-01-01

A formalism for target fragment transport is presented with application to energy loss spectra in thin silicon devices. Predicted results are compared to experiments with the surface barrier detectors of McNulty et al. The intranuclear cascade nuclear reaction model does not predict the McNulty experimental data for the highest energy events. A semiempirical nuclear cross section gives an adequate explanation of McNulty's experiments. Application of the formalism to specific electronic devices is discussed.

Radiation Resistance of the U(Al, Si)3 Alloy: Ion-Induced Disordering

PubMed Central

Yaniv, Gili; Horak, Pavel; Vacik, Jiri; Mykytenko, Natalia; Rafailov, Gennady; Dahan, Itzchak; Fuks, David; Kiv, Arik

2018-01-01

During the exploitation of nuclear reactors, various U-Al based ternary intermetallides are formed in the fuel-cladding interaction layer. Structure and physical properties of these intermetallides determine the radiation resistance of cladding and, ultimately, the reliability and lifetime of the nuclear reactor. In current research, U(Al, Si)3 composition was studied as a potential constituent of an interaction layer. Phase content of the alloy of an interest was ordered U(Al, Si)3, structure of which was reported earlier, and pure Al (constituting less than 20 vol % of the alloy). This alloy was investigated prior and after the irradiation performed by Ar ions at 30 keV. The irradiation was performed on the transmission electron microscopy (TEM, JEOL, Japan) samples, characterized before and after the irradiation process. Irradiation induced disorder accompanied by stress relief. Furthermore, it was found that there is a dose threshold for disordering of the crystalline matter in the irradiated region. Irradiation at doses equal or higher than this threshold resulted in almost solely disordered phase. Using the program “Stopping and Range of Ions in Matter” (SRIM), the parameters of penetration of Ar ions into the irradiated samples were estimated. Based on these estimations, the dose threshold for ion-induced disordering of the studied material was assessed. PMID:29393870

Radiation Resistance of the U(Al, Si)₃ Alloy: Ion-Induced Disordering.

PubMed

Meshi, Louisa; Yaniv, Gili; Horak, Pavel; Vacik, Jiri; Mykytenko, Natalia; Rafailov, Gennady; Dahan, Itzchak; Fuks, David; Kiv, Arik

2018-02-02

During the exploitation of nuclear reactors, various U-Al based ternary intermetallides are formed in the fuel-cladding interaction layer. Structure and physical properties of these intermetallides determine the radiation resistance of cladding and, ultimately, the reliability and lifetime of the nuclear reactor. In current research, U(Al, Si)₃ composition was studied as a potential constituent of an interaction layer. Phase content of the alloy of an interest was ordered U(Al, Si)₃, structure of which was reported earlier, and pure Al (constituting less than 20 vol % of the alloy). This alloy was investigated prior and after the irradiation performed by Ar ions at 30 keV. The irradiation was performed on the transmission electron microscopy (TEM, JEOL, Japan) samples, characterized before and after the irradiation process. Irradiation induced disorder accompanied by stress relief. Furthermore, it was found that there is a dose threshold for disordering of the crystalline matter in the irradiated region. Irradiation at doses equal or higher than this threshold resulted in almost solely disordered phase. Using the program "Stopping and Range of Ions in Matter" (SRIM), the parameters of penetration of Ar ions into the irradiated samples were estimated. Based on these estimations, the dose threshold for ion-induced disordering of the studied material was assessed.

Disease of the kidney and of the urinary tract in De Medicina Methodica (Padua, 1611) of Prospero Alpini (1563-1616).

PubMed

De Santo, Natale Gaspare; Bisaccia, Carmela; Ricciardi, Biagio; Anastasio, Pietro; Aliotta, Giovanni; Ongaro, Giuseppe

2016-02-01

The study was devised to understand the contribution to nephrology ofDe Medicina Methodicaof Prospero Alpini published in 1511, at a time when the fame of the professor reached the azimuth. We have analyzed the contents of chapters devoted to nephrology in that book of Prospero Alpini and the novelties of his message. Prospero Alpini (1563-1616) taught at the University of Padua (1594-1616), at the same time of Galileo Galilei, Santorio Santorio, and Girolamo Fabrizi dAcquapendente, when measurements (pulse, temperature, perspiration) were introduced into medicine. He was a travelling physician to whom we owe fundamental contributions to the use of urine to prognosticate life and death (De Praesagienda vita et morte aegrotantium libri septem, Venetiis, apud Haeredes Melchioris Sessae,1601). As prefect of the Botanical Garden - the first ever and a model in the world - he could turn the study of simples into cures(De Medicina Methodica Libri Tredecim. Patavi, apud Franciscum Bolzettam, 1611. Ex typographia Laurentij Pasquali, is anin foliovolume of XLVII + 424 pages, 54 lines per page), wherein Alpini aimed to rejuvenate antique medical Methodism. It is a testimony of the interest of medicine philosophers of the modern era for the corpuscular and atomic ideas (Nancy Siraisi). Methodists (2ndCentury BC) refused anatomy and physiology as unique guidelines to the interpretations of diseases and gave importance to the development of a pharmacological science and alternative medicine. The book begins with a 3 page letter to Francis Maria della Rovere Duke of Montefeltro, and a 2 page letter to the readers. We discuss the novelties of the chapters on renal colic (de dolorerenum), hematuria (de sanguinis profluvium), pyuria, anuria (de urina suppressa) and its cure, polyuria (de urina profluvio), renal abscesses, hydrops and its treatment by skin incisions. We also analyze the chapter on kidney and bladder stones (Book X, Chapter XVIII, pp. 354-356) - a masterpiece of

In-Situ Studies of Structure Transformation and Al Coordination of KAl(MoO4)2 during Heating by High Temperature Raman and 27Al NMR Spectroscopies

PubMed Central

Wang, Min; You, Jinglin; Sobol, Alexander; Lu, Liming; Wang, Jian; Xie, Yingfang

2017-01-01

Recent interest in optimizing composition and synthesis conditions of functional crystals, and the further exploration of new possible candidates for tunable solid-state lasers, has led to significant research on compounds in this family MIMIII(MVIO4)2 (MI = alkali metal, MIII = Al, In, Sc, Fe, Bi, lanthanide; MVI = Mo, W). The vibrational modes, structure transformation, and Al coordination of crystalline, glassy, and molten states of KAl(MoO4)2 have been investigated by in-situ high temperature Raman scattering and 27Al magic angle spinning nuclear magnetic resonance (MAS NMR) spectroscopy, together with first principles density functional simulation of room temperature Raman spectrum. The results showed that, under the present fast quenching conditions, Al is present predominantly in [AlO6] octahedra in both KAl(MoO4)2 glass and melt, with the tetrahedrally coordinated Al being minor at approximately 2.7%. The effect of K+, from ordered arrangement in the crystal to random distribution in the melt, on the local chemical environment of Al, was also revealed. The distribution and quantitative analysis of different Al coordination subspecies are final discussed and found to be dependent on the thermal history of the glass samples. PMID:28772669

[Theses on hepatitis at the Faculdade de Medicina of the Universidade Federal do Rio de Janeiro, 1837-2000].

PubMed

Gaze, Rosangela; Carvalho, Diana Maul de; Tura, Luiz Fernando Rangel; Martins, Carolina Passos Telles Taveira; Lobato, Vanessa Maria Tavares

2012-06-01

An inventory of the theses on hepatitis of the Faculdade de Medicina of the Universidade Federal do Rio de Janeiro between 1837 and 2000 is presented. The analysis indicates the potential and limits for discussion of the evolutionary framework of scientific knowledge on these health problems in Brazil. The theories are also discussed in light of their scientific reference points and the technological and social changes that influenced them. The landmarks in medical education and knowledge about hepatitis are identified and categorized, considering that the theses reveal at the very least the state of the art on the subject. The study makes it possible to explore the foundations upon which the scientific knowledge on hepatitis were built and indicate possibilities for research in the reconstruction of scientific knowledge of other health problems.

In-Situ Studies of Structure Transformation and Al Coordination of KAl(MoO₄)₂ during Heating by High Temperature Raman and 27Al NMR Spectroscopies.

PubMed

Wang, Min; You, Jinglin; Sobol, Alexander; Lu, Liming; Wang, Jian; Xie, Yingfang

2017-03-17

Recent interest in optimizing composition and synthesis conditions of functional crystals, and the further exploration of new possible candidates for tunable solid-state lasers, has led to significant research on compounds in this family M I M III (M VI O₄)₂ (M I = alkali metal, M III = Al, In, Sc, Fe, Bi, lanthanide; M VI = Mo, W). The vibrational modes, structure transformation, and Al coordination of crystalline, glassy, and molten states of KAl(MoO₄)₂ have been investigated by in-situ high temperature Raman scattering and 27 Al magic angle spinning nuclear magnetic resonance (MAS NMR) spectroscopy, together with first principles density functional simulation of room temperature Raman spectrum. The results showed that, under the present fast quenching conditions, Al is present predominantly in [AlO₆] octahedra in both KAl(MoO₄)₂ glass and melt, with the tetrahedrally coordinated Al being minor at approximately 2.7%. The effect of K⁺, from ordered arrangement in the crystal to random distribution in the melt, on the local chemical environment of Al, was also revealed. The distribution and quantitative analysis of different Al coordination subspecies are final discussed and found to be dependent on the thermal history of the glass samples.

Stellar reaction rate for {sup 22}Mg+p->{sup 23}Al from the asymptotic normalization coefficient in the mirror nuclear system {sup 22}Ne+n->{sup 23}Ne

DOE Office of Scientific and Technical Information (OSTI.GOV)

Al-Abdullah, T.; Physics Department, Hashemite University, Zarqa 13115; Carstoiu, F.

2010-03-15

The production of {sup 22}Na in ONe novae can be influenced by the {sup 22}Mg(p,gamma){sup 23}Al reaction. To investigate this reaction rate at stellar energies, we have determined the asymptotic normalization coefficient (ANC) for {sup 22}Mg+p->{sup 23}Al through measurements of the ANCs in the mirror nuclear system {sup 22}Ne+n->{sup 23}Ne. The peripheral neutron-transfer reactions {sup 13}C({sup 12}C,{sup 13}C){sup 12}C and {sup 13}C({sup 22}Ne,{sup 23}Ne){sup 12}C were studied. The identical entrance and exit channels of the first reaction make it possible to extract independently the ground-state ANC in {sup 13}C. Our experiment gives C{sub p{sub 1/2}}{sup 2}({sup 13}C)=2.24+-0.11 fm{sup -1}, whichmore » agrees with the value obtained from several previous measurements. The weighted average for all the obtained C{sub p{sub 1/2}}{sup 2} is 2.31+-0.08 fm{sup -1}. This value is adopted to be used in obtaining the ANCs in {sup 23}Ne. The differential cross sections for the reaction {sup 13}C({sup 22}Ne,{sup 23}Ne){sup 12}C leading to the J{sup {pi}}=5/2{sup +} and 1/2{sup +} states in {sup 23}Ne have been measured at 12 MeV/u. Optical model parameters for use in the DWBA calculations were obtained from measurements of the elastic scatterings {sup 22}Ne+{sup 13}C and {sup 22}Ne+{sup 12}C. The extracted ANC for the ground state in {sup 23}Ne, C{sub d{sub 5/2}}{sup 2}=0.86+-0.08+-0.12 fm{sup -1}, is converted to its corresponding value in {sup 23}Al using mirror symmetry to give C{sub d{sub 5/2}}{sup 2}({sup 23}Al)=(4.63+-0.77)x10{sup 3} fm{sup -1}. The astrophysical S factor S(0) for the {sup 22}Mg(p,gamma) reaction was determined to be 0.96+-0.11 keV b. The consequences for nuclear astrophysics are discussed.« less

Can Nuclear Terrorists be Deterred?

NASA Astrophysics Data System (ADS)

Ferguson, Charles

2005-04-01

Conventional thinking since September 11, 2001, posits that nuclear-armed terrorists cannot be deterred. However, not all terrorist groups are alike. For instance, those that are strongly affiliated with a national territory or a constituency that can be held hostage are more likely to be self-deterred against using or even acquiring nuclear weapons. In contrast, international terrorist organizations, such as al Qaeda, or apocalyptic groups, such as Aum Shinrikyo, may welcome retaliatory nuclear strikes because they embrace martyrdom. Such groups may be immune to traditional deterrence, which threatens direct punishment against the group in question or against territory or people the terrorists' value. Although deterring these groups may appear hopeless, nuclear forensic techniques could provide the means to establish deterrence through other means. In particular, as long as the source of the nuclear weapon or fissile material could be identified, the United States could threaten a retaliatory response against a nation that did not provide adequate security for its nuclear weapons or weapons-usable fissile material. This type of deterrent threat could be used to compel the nation with lax security to improve its security to meet rigorous standards.

Next Generation Sequencing and ALS: known genes, different phenotyphes.

PubMed

Campopiano, Rosa; Ryskalin, Larisa; Giardina, Emiliano; Zampatti, Stefania; Busceti, Carla L; Biagioni, Francesca; Ferese, Rosangela; Storto, Marianna; Gambardella, Stefano; Fornai, Francesco

2017-12-01

Amyotrophic lateral sclerosis (ALS) is fatal neurodegenerative disease clinically characterized by upper and lower motor neuron dysfunction resulting in rapidly progressive paralysis and death from respiratory failure. Most cases appear to be sporadic, but 5-10 % of cases have a family history of the disease, and over the last decade, identification of mutations in about 20 genes predisposing to these disorders has provided the means to better understand their pathogenesis. Next Generation sequencing (NGS) is an advanced high-throughput DNA sequencing technology which have rapidly contributed to an acceleration in the discovery of genetic risk factors for both familial and sporadic neurological and neurodegenerative diseases. These strategies allowed to rapidly identify disease-associated variants and genetic risk factors for both familial (fALS) and sporadic ALS (sALS), strongly contributing to the knowledge of the genetic architecture of ALS. Moreover, as the number of ALS genes grows, many of the proteins they encode are in intracellular processes shared with other known diseases, suggesting an overlapping of clinical and phatological features between different diseases. To emphasize this concept, the review focuses on genes coding for Valosin-containing protein (VPC) and two Heterogeneous nuclear RNA-binding proteins (HNRNPA1 and hnRNPA2B1), recently idefied through NGS, where different mutations have been associated in both ALS and other neurological and neurodegenerative diseases.

75 FR 28664 - Southern Nuclear Operating Company; Notice of Availability of Environmental Assessment and...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-21

... NUCLEAR REGULATORY COMMISSION [Docket No. 52-011; NRC-2008-0252] Southern Nuclear Operating Company; Notice of Availability of Environmental Assessment and Finding of No Significant Impact for License Amendment to Early Site Permit Issued to Southern Nuclear Operating Company et al., for Vogtle Electric Generating Plant ESP Site Located in Burke...

Geologic isolation of nuclear waste at high latitudes: the role of ice sheets

USGS Publications Warehouse

Person, M.; McIntosh, J.; Iverson, N.; Neuzil, C.E.; Bense, V.

2012-01-01

Geologic isolation of high-level nuclear waste from the biosphere requires special consideration in countries at high latitudes (>40°N) owing to the possibility of future episodes of continental glaciation (Talbot 1999). It is now widely recognized that Pleistocene continental glaciations have had a profound effect on rates of sediment erosion (Cuffey & Paterson 2010) and deformation including tectonic thrusting (Pedersen 2005) as well as groundwater flow (Person et al. 2007; Lemieux et al. 2008a,b,c). In addition, glacial mechanical loads may have generated anomalous, or fossil, pore pressures within certain clay-rich confining units (e.g. Vinard et al. 2001). Because high-level nuclear wastes must be isolated from the biosphere as long as 1 million years (McMurry et al. 2003), the likelihood of one or more continental ice sheets overrunning high-latitude sites must be considered.

[Productivity, visibility and citation analysis of the Revista Peruana de Medicina Experimental y Salud Pública, 2002-2009].

PubMed

Huamaní, Charles

2010-09-01

Biomedical journals are the most used and important venue to disseminate and interchange scientific information, and evaluation is an important component. A bibliometric study was conducted on the productivity, visibility and citation analysis of the Revista Peruana de Medicina Experimental y Salud Pública (RPMESP), from 2002 to 2009. During this period, the RPMESP published about 62 documents per year, 55.3% were research articles. The visibility of RPMESP, determined among three databases (SISBIB-UNMSM, SciELO-Peru, and REDALYC), was irregular, increasing on July 2006, with the highest access on October 2009 (117,618 hits). 43.0% of publications were cited. The calculated impact factor in ISI journals was 0.04 in 2009. In conclusion, the citation of RPMESP shows a slowly growing during the period 2002-2009. It is hoped that the RPMESP increase its visibility and impact after its inclusion in MEDLINE.

De novo design of RNA-binding proteins with a prion-like domain related to ALS/FTD proteinopathies.

PubMed

Mitsuhashi, Kana; Ito, Daisuke; Mashima, Kyoko; Oyama, Munenori; Takahashi, Shinichi; Suzuki, Norihiro

2017-12-04

Aberrant RNA-binding proteins form the core of the neurodegeneration cascade in spectrums of disease, such as amyotrophic lateral sclerosis (ALS)/frontotemporal dementia (FTD). Six ALS-related molecules, TDP-43, FUS, TAF15, EWSR1, heterogeneous nuclear (hn)RNPA1 and hnRNPA2 are RNA-binding proteins containing candidate mutations identified in ALS patients and those share several common features, including harboring an aggregation-prone prion-like domain (PrLD) containing a glycine/serine-tyrosine-glycine/serine (G/S-Y-G/S)-motif-enriched low-complexity sequence and rich in glutamine and/or asparagine. Additinally, these six molecules are components of RNA granules involved in RNA quality control and become mislocated from the nucleus to form cytoplasmic inclusion bodies (IBs) in the ALS/FTD-affected brain. To reveal the essential mechanisms involved in ALS/FTD-related cytotoxicity associated with RNA-binding proteins containing PrLDs, we designed artificial RNA-binding proteins harboring G/S-Y-G/S-motif repeats with and without enriched glutamine residues and nuclear-import/export-signal sequences and examined their cytotoxicity in vitro. These proteins recapitulated features of ALS-linked molecules, including insoluble aggregation, formation of cytoplasmic IBs and components of RNA granules, and cytotoxicity instigation. These findings indicated that these artificial RNA-binding proteins mimicked features of ALS-linked molecules and allowed the study of mechanisms associated with gain of toxic functions related to ALS/FTD pathogenesis.

U.S. Strategic Nuclear Policy and Force Structure: Three Analytical Approaches

DTIC Science & Technology

1999-12-01

research rocket fired from Norway, an incident that sparked strong concerns that nuclear war 18 Lachlan Forrow, Bruce Blair, Ira Helfnad, George Lewis...quoted in R. Jeffrey Smith , "Clinton Directive Changes Strategy On Nuclear Arms," Washington Post, 7 December 1997, Al. 86 President William...Meyers, "U.S. Updates Nuclear War Guidelines," New York Times, 8 December 1997, 4. 233 Bell quoted in R. Jeffrey Smith , "Clinton Directive Changes

China’s Future Nuclear Submarine Force. Insights from Chinese Writings

DTIC Science & Technology

2007-01-01

ts056058.pdf. 115. , , [Lu Jiaben, Wang Shen- glong, Liu Wen, et al.], “‘ ’ ” [Evaluation of Health Protective Effects of “Silver Ginseng ...Based on his instructions, in the course of developing nuclear-powered submarines, we formed a seamless and effective nuclear safety mechanism by...the manner in which France strives to maximize the effectiveness of its second-tier nuclear submarine force.32 The September 2005 issue of (Naval

Nuclear equation of state for core-collapse supernova simulations with realistic nuclear forces

NASA Astrophysics Data System (ADS)

Togashi, H.; Nakazato, K.; Takehara, Y.; Yamamuro, S.; Suzuki, H.; Takano, M.

2017-05-01

A new table of the nuclear equation of state (EOS) based on realistic nuclear potentials is constructed for core-collapse supernova numerical simulations. Adopting the EOS of uniform nuclear matter constructed by two of the present authors with the cluster variational method starting from the Argonne v18 and Urbana IX nuclear potentials, the Thomas-Fermi calculation is performed to obtain the minimized free energy of a Wigner-Seitz cell in non-uniform nuclear matter. As a preparation for the Thomas-Fermi calculation, the EOS of uniform nuclear matter is modified so as to remove the effects of deuteron cluster formation in uniform matter at low densities. Mixing of alpha particles is also taken into account following the procedure used by Shen et al. (1998, 2011). The critical densities with respect to the phase transition from non-uniform to uniform phase with the present EOS are slightly higher than those with the Shen EOS at small proton fractions. The critical temperature with respect to the liquid-gas phase transition decreases with the proton fraction in a more gradual manner than in the Shen EOS. Furthermore, the mass and proton numbers of nuclides appearing in non-uniform nuclear matter with small proton fractions are larger than those of the Shen EOS. These results are consequences of the fact that the density derivative coefficient of the symmetry energy of our EOS is smaller than that of the Shen EOS.

Irradiation of Wrought FeCrAl Tubes in the High Flux Isotope Reactor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Linton, Kory D.; Field, Kevin G.; Petrie, Christian M.

The Advanced Fuels Campaign within the Nuclear Technology Research and Development program of the Department of Energy Office of Nuclear Energy is seeking to improve the accident tolerance of light water reactors. Alumina-forming ferritic alloys (e.g., FeCrAl) are one of the leading candidate materials for fuel cladding to replace traditional zirconium alloys because of the superior oxidation resistance of FeCrAl. However, there are still some unresolved questions regarding irradiation effects on the microstructure and mechanical properties of FeCrAl at end-of-life dose levels. In particular, there are concerns related to irradiation-induced embrittlement of FeCrAl alloys due to secondary phase formation. Tomore » address this issue, Oak Ridge National Laboratory has developed a new experimental design to irradiate shortened cladding tube specimens with representative 17×17 array pressurized water reactor diameter and thickness in the High Flux Isotope Reactor (HFIR) under relevant temperatures (300–350°C). Post-irradiation examination will include studies of dimensional change, microstructural changes, and mechanical performance. This report briefly summarizes the capsule design concept and the irradiation test matrix for six rabbit capsules. Each rabbit contains two FeCrAl alloy tube specimens. The specimens include Generation I and Generation II FeCrAl alloys with varying processing conditions, Cr concentrations, and minor alloying elements. The rabbits were successfully assembled, welded, evaluated, and delivered to the HFIR along with a complete quality assurance fabrication package. Pictures of the rabbit assembly process and detailed dimensional inspection of select specimens are included in this report. The rabbits were inserted into HFIR starting in cycle 472 (May 2017).« less

ExoMol line lists XXVIII: The rovibronic spectrum of AlH

NASA Astrophysics Data System (ADS)

Yurchenko, Sergei N.; Williams, Henry; Leyland, Paul C.; Lodi, Lorenzo; Tennyson, Jonathan

2018-06-01

A new line list for AlH is produced. The WYLLoT line list spans two electronic states X 1Σ+ and A 1Π. A diabatic model is used to model the shallow potential energy curve of the A 1Π state, which has a strong pre-dissociative character with only two bound vibrational states. Both potential energy curves are empirical and were obtained by fitting to experimentally derived energies of the X 1Σ+ and A 1Π electronic states using the diatomic nuclear motion codes DPOTFIT and DUO. High temperature line lists plus partition functions and lifetimes for three isotopologues 27AlH, 27AlD and 26AlH were generated using ab initio dipole moments. The line lists cover both the X-X and A-X systems and are made available in electronic form at the CDS and ExoMol databases.

Second Annual Progress Report on Radiation Tolerance of Controlled Fusion Welds in High Temperature Oxidation Resistant FeCrAl Alloys

DOE Office of Scientific and Technical Information (OSTI.GOV)

Field, Kevin G.; Gussev, Maxim N.; Yamamoto, Yukinori

2016-12-30

The present report summarizes and discusses the current results and on-going activity towards developing a modern, nuclear grade FeCrAl alloy designed to have enhanced radiation tolerance and weldability under the Department of Energy (DOE) Nuclear Energy Enabling Technologies (NEET) program.

VizieR Online Data Catalog: Arcetri Catalogue of H2O Maser Sources (Brand+ 1994)

NASA Astrophysics Data System (ADS)

Brand, J.; Cesaroni, R.; Caselli, P.; Catarzi, M.; Codella, C.; Comoretto, G.; Curioni, G. P.; Curioni, P.; di, Franco S.; Felli, M.; Giovanardi, C.; Olmi, L.; Palagi, F.; Palla, F.; Panella, D.; Pareschi, G.; Rossi, E.; Speroni, N.; Tofani, G.

1993-11-01

An update is presented of the Arcetri Atlas of water masers (Comoretto et al. 1990A&AS...84..179C). It contains the results of observations of water masers with the Medicina 32-m antenna. The observed sources were all discovered in the period 1989-1993, and were found either directly in the course of our own programs or were taken from the literature in which case they were re-observed at Medicina. We give the observed parameters of 214 sources in tabular form, and present all the spectra of the 141 detections. (2 data files).

Neurology at Escola Paulista de Medicina (1933-1995). From Fausto Guerner to José Geraldo Camargo Lima.

PubMed

Ferraz, Henrique Ballalai; Neves, Afonso Carlos

2015-02-01

Escola Paulista de Medicina (EPM) was founded in 1933 and the first Professor of Neurology was Fausto Guerner, who could not effectively assume the teaching activities due to his premature death in 1938. Professor Guerner had had his neurological training at Paris. Professor Longo was his successor. Longo was one of the founders of Arquivos de Neuro-Psiquiatria the foremost journal of neurosciences in Latin American. Longo died in 1967 and Professor Paulo Pupo succeeded him. Pupo introduced electroencephalography in Brazil. After his death in 1970, Professor Dante Giorgi succeeded him until 1974. Professor José Geraldo Camargo Lima took over the position after Giorgi's death. He created the Neurological Emergency unit, initiated the Post-Graduation in Neurology and divided the Discipline in specialized units. During the 1980's and until his retirement in 1995, EPM had become one of most important centers of Brazil training neurologists and researchers in neurological sciences.

Hydrothermal Synthesis and Characterization of Ni-Al Montmorillonite-Like Phyllosilicates

PubMed Central

Reinholdt, Marc X.; Brendlé, Jocelyne; Tuilier, Marie-Hélène; Kaliaguine, Serge; Ambroise, Emmanuelle

2013-01-01

This work describes the first hydrothermal synthesis in fluoride medium of Ni-Al montmorillonite-like phyllosilicates, in which the only metallic elements in the octahedral sheet are Ni and Al. X-ray diffraction , chemical analysis, thermogravimetric and differential thermal analysis, scanning electron microscopy and transmission electron microscopy confirm that the synthesized samples are montmorillonite-like phyllosilicates having the expected chemical composition. The specific surface areas of the samples are relatively large (>100 m2 g−1) compared to naturally occurring montmorillonites. 29Si and 27Al nuclear magnetic resonance (NMR) indicate substitutions of Al for Si in the tetrahedral sheet. 19F NMR and Ni K-edge extended X-ray absorption fine structure (EXAFS) local probes highlight a clustering of the metal elements and of the vacancies in the octahedral sheet of the samples. These Ni-Al phyllosilicates exhibit a higher local order than in previously synthesized Zn-Al phyllosilicates. Unlike natural montmorillonites, where the distribution of transition metal cations ensures a charge equilibrium allowing a stability of the framework, synthetic montmorillonites entail clustering and instability of the lattice when the content of divalent element in the octahedral sheet exceeds ca. 20%. Synthesis of Ni-Al montmorillonite-like phyllosilicates, was successfully achieved for the first time. These new synthetic materials may find potential applications as catalysts or as materials with magnetic, optical or staining properties. PMID:28348321

75 FR 5357 - In the Matter of Entergy Nuclear Operations, Inc., et al.; Order Extending the Effectiveness of...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-02-02

...). Pilgrim is a boiling water nuclear reactor that is owned by Entergy Nuclear and operated by ENO. The... Generating Unit No. 1 (IP1). IP1 is a pressurized water nuclear reactor that is owned by ENIP2 and maintained... nuclear reactors that are owned by ENIP2 and ENIP3, respectively, and operated by ENO. The facilities are...

Study on underclad cracking in nuclear reactor vessel steels

DOE Office of Scientific and Technical Information (OSTI.GOV)

Horiya, T.; Takeda, T.; Yamato, K.

1985-02-01

Susceptibility to underclad cracking in nuclear reactor vessel steels, such as SA533 Grade B Class 1 and SA508 Class 2, was studied in detail. A convenient simulation test method using simulated HAZ specimens of small size has been developed for quantitative evaluation of susceptibility to underclad cracks. The method can predict precisely the cracking behavior in weldments of steels with relative low crack susceptibility. The effect of chemical compositions on susceptibility to the cracking was examined systematically using the developed simulation test method and the following index was obtained from the test results: U = 20(V) + 7(C) + 4(Mo)more » + (Cr) + (Cu) - 0.5(Mn) + 1.5 log(X) X = Al . . . Al/2N less than or equal to 1 X = 2N . . . Al/2N > 1 It was confirmed that the new index (U) is useful for the prediction of crack susceptibility of the nuclear vessel steels; i.e., no crack initiation is detected in weldments in the roller bend test for steels having U value below 0.90.« less

Nuclear Data Sheets for A=37

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cameron J.; Nica N.; Cameron,J.

2012-02-01

Nuclear spectroscopic information for experimentally investigated nuclides of mass 37 (Na, Mg, Al, Si, P, S, Cl, Ar, K, Ca) has been evaluated. The principal sources of the 'adopted levels' presented for nuclides close to the stability line are Endt's evaluations (1990En08, 1978En02). The data sets for reactions and decays, including all available gamma-ray data, are based mostly on the original literature. There are no data available for the excited states in {sup 37}Na, {sup 37}Mg, {sup 37}Al; and for {sup 37}Si, only one excited state is known.

Mechanical properties of neutron-irradiated model and commercial FeCrAl alloys

NASA Astrophysics Data System (ADS)

Field, Kevin G.; Briggs, Samuel A.; Sridharan, Kumar; Howard, Richard H.; Yamamoto, Yukinori

2017-06-01

The development and understanding of the mechanical properties of neutron-irradiated FeCrAl alloys is increasingly a critical need as these alloys continue to become more mature for nuclear reactor applications. This study focuses on the mechanical properties of model FeCrAl alloys and of a commercial FeCrAl alloy neutron-irradiated to up to 13.8 displacements per atom (dpa) at irradiation temperatures between 320 and 382 °C. Tensile tests were completed at room temperature and at 320 °C, and a subset of fractured tensile specimens was examined by scanning electron microscopy. Results showed typical radiation hardening and embrittlement indicative of high chromium ferritic alloys with strong chromium composition dependencies at lower doses. At and above 7.0 dpa, the mechanical properties saturated for both the commercial and model FeCrAl alloys, although brittle cleavage fracture was observed at the highest dose in the model FeCrAl alloy with the highest chromium content (18 wt %). The results suggest the composition and microstructure of FeCrAl alloys plays a critical role in the mechanical response of FeCrAl alloys irradiated near temperatures relevant to light water reactors.

Rotational relaxation of AlO+(1Σ+) in collision with He

NASA Astrophysics Data System (ADS)

Denis-Alpizar, O.; Trabelsi, T.; Hochlaf, M.; Stoecklin, T.

2018-03-01

The rate coefficients for the rotational de-excitation of AlO+ by collisions with He are determined. The possible production mechanisms of the AlO+ ion in both diffuse and dense molecular clouds are first discussed. A set of ab initio interaction energies is computed at the CCSD(T)-F12 level of theory, and a three-dimensional analytical model of the potential energy surface is obtained using a linear combination of reproducing kernel Hilbert space polynomials together with an analytical long range potential. The nuclear spin free close-coupling equations are solved and the de-excitation rotational rate coefficients for the lower 15 rotational states of AlO+ are reported. A propensity rule to favour Δj = -1 transitions is obtained while the hyperfine resolved state-to-state rate coefficients are also discussed.

First Annual Progress Report on Radiation Tolerance of Controlled Fusion Welds in High Temperature Oxidation Resistant FeCrAl Alloys

DOE Office of Scientific and Technical Information (OSTI.GOV)

Field, Kevin G.; Gussev, Maxim N.; Hu, Xunxiang

2015-12-01

The present report summarizes and discusses the first year efforts towards developing a modern, nuclear grade FeCrAl alloy designed to have enhanced radiation tolerance and weldability under the Department of Energy (DOE) Nuclear Energy Enabling Technologies (NEET) program. Significant efforts have been made within the first year of this project including the fabrication of seven candidate FeCrAl alloys with well controlled chemistry and microstructure, the microstructural characterization of these alloys using standardized and advanced techniques, mechanical properties testing and evaluation of base alloys, the completion of welding trials and production of weldments for subsequent testing, the design of novel tensilemore » specimen geometry to increase the number of samples that can be irradiated in a single capsule and also shorten the time of their assessment after irradiation, the development of testing procedures for controlled hydrogen ingress studies, and a detailed mechanical and microstructural assessment of weldments prior to irradiation or hydrogen charging. These efforts and research results have shown promise for the FeCrAl alloy class as a new nuclear grade alloy class.« less

The scientific authorship of Doctor Chernoviz, from the popularization of medicine to professional training: the Dicionário de medicina popular, 1842-1890.

PubMed

Medeiros, Aline da Silva

2018-03-01

This article reflects on the scientific authorship of Pedro Luiz Napoleão Chernoviz, based on his Dicionário de medicina popular, which was published in six editions between 1842 and 1890. The first part of the text discusses Chernoviz's position within the regimes of scientific authorship which were present in the medical community in Rio de Janeiro. Next, we analyze the author's arguments justifying a text that popularized medical science while this field strove for exclusivity in the practice of medicine. Finally, we suggest new meanings around Chernoviz's scientific authorship based on how the Dicionário was used and read by an initiated public.

Ambient Dose Equivalent measured at the Instituto Nacional de Cancerología Department of Nuclear Medicine

NASA Astrophysics Data System (ADS)

Ávila, O.; Torres-Ulloa, C. L.; Medina, L. A.; Trujillo-Zamudio, F. E.; de Buen, I. Gamboa; Buenfil, A. E.; Brandan, M. E.

2010-12-01

Ambient dose equivalent values were determined in several sites at the Instituto Nacional de Cancerología, Departmento de Medicina Nuclear, using TLD-100 and TLD-900 thermoluminescent dosemeters. Additionally, ambient dose equivalent was measured at a corridor outside the hospitalization room for patients treated with 137Cs brachytherapy. Dosemeter calibration was performed at the Instituto Nacional de Investigaciones Nucleares, Laboratorio de Metrología, to known 137Cs gamma radiation air kerma. Radionuclides considered for this study are 131I, 18F, 67Ga, 99mTc, 111In, 201Tl and 137Cs, with main gamma energies between 93 and 662 keV. Dosemeters were placed during a five month period in the nuclear medicine rooms (containing gamma-cameras), injection corridor, patient waiting areas, PET/CT study room, hot lab, waste storage room and corridors next to the hospitalization rooms for patients treated with 131I and 137Cs. High dose values were found at the waste storage room, outside corridor of 137Cs brachytherapy patients and PET/CT area. Ambient dose equivalent rate obtained for the 137Cs brachytherapy corridor is equal to (18.51±0.02)×10-3 mSv/h. Sites with minimum doses are the gamma camera rooms, having ambient dose equivalent rates equal to (0.05±0.03)×10-3 mSv/h. Recommendations have been given to the Department authorities so that further actions are taken to reduce doses at high dose sites in order to comply with the ALARA principle (as low as reasonably achievable).

Ambient Dose Equivalent measured at the Instituto Nacional de Cancerologia Department of Nuclear Medicine

DOE Office of Scientific and Technical Information (OSTI.GOV)

Avila, O.; Torres-Ulloa, C. L.; Facultad de Ciencias, Universidad Nacional Autonoma de Mexico, AP 70-542, 04510, DF

2010-12-07

Ambient dose equivalent values were determined in several sites at the Instituto Nacional de Cancerologia, Departmento de Medicina Nuclear, using TLD-100 and TLD-900 thermoluminescent dosemeters. Additionally, ambient dose equivalent was measured at a corridor outside the hospitalization room for patients treated with {sup 137}Cs brachytherapy. Dosemeter calibration was performed at the Instituto Nacional de Investigaciones Nucleares, Laboratorio de Metrologia, to known {sup 137}Cs gamma radiation air kerma. Radionuclides considered for this study are {sup 131}I, {sup 18}F, {sup 67}Ga, {sup 99m}Tc, {sup 111}In, {sup 201}Tl and {sup 137}Cs, with main gamma energies between 93 and 662 keV. Dosemeters were placedmore » during a five month period in the nuclear medicine rooms (containing gamma-cameras), injection corridor, patient waiting areas, PET/CT study room, hot lab, waste storage room and corridors next to the hospitalization rooms for patients treated with {sup 131}I and {sup 137}Cs. High dose values were found at the waste storage room, outside corridor of {sup 137}Cs brachytherapy patients and PET/CT area. Ambient dose equivalent rate obtained for the {sup 137}Cs brachytherapy corridor is equal to (18.51{+-}0.02)x10{sup -3} mSv/h. Sites with minimum doses are the gamma camera rooms, having ambient dose equivalent rates equal to (0.05{+-}0.03)x10{sup -3} mSv/h. Recommendations have been given to the Department authorities so that further actions are taken to reduce doses at high dose sites in order to comply with the ALARA principle (as low as reasonably achievable).« less

76 FR 50767 - Southern Nuclear Operating Co., et al.; Combined Licenses for Vogtle Electric Generating Plant...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-08-16

... Limited Work Authorizations AGENCY: Nuclear Regulatory Commission. ACTION: Notice of hearing. SUMMARY: The... Southern Nuclear Operating Company for two combined licenses (COLs) seeking approval to construct and...), as well as for two limited work authorizations (LWAs) to engage in selected construction activities...

Nuclear egress of TDP-43 and FUS occurs independently of Exportin-1/CRM1.

PubMed

Ederle, Helena; Funk, Christina; Abou-Ajram, Claudia; Hutten, Saskia; Funk, Eva B E; Kehlenbach, Ralph H; Bailer, Susanne M; Dormann, Dorothee

2018-05-04

TDP-43 and FUS are nuclear proteins with multiple functions in mRNA processing. They play key roles in ALS (amyotrophic lateral sclerosis) and FTD (frontotemporal dementia), where they are partially lost from the nucleus and aggregate in the cytoplasm of neurons and glial cells. Defects in nucleocytoplasmic transport contribute to this pathology, hence nuclear import of both proteins has been studied in detail. However, their nuclear export routes remain poorly characterized and it is unclear whether aberrant nuclear export contributes to TDP-43 or FUS pathology. Here we show that predicted nuclear export signals in TDP-43 and FUS are non-functional and that both proteins are exported independently of the export receptor CRM1/Exportin-1. Silencing of Exportin-5 or the mRNA export factor Aly/REF, as well as mutations that abrogate RNA-binding do not impair export of TDP-43 and FUS. However, artificially enlarging TDP-43 or FUS impairs their nuclear egress, suggesting that they could leave the nucleus by passive diffusion. Finally, we found that inhibition of transcription causes accelerated nuclear egress of TDP-43, suggesting that newly synthesized RNA retains TDP-43 in the nucleus, limiting its egress into the cytoplasm. Our findings implicate reduced nuclear retention as a possible factor contributing to mislocalization of TDP-43 in ALS/FTD.

Interaction of curcumin with Al(III) and its complex structures based on experiments and theoretical calculations

NASA Astrophysics Data System (ADS)

Jiang, Teng; Wang, Long; Zhang, Sui; Sun, Ping-Chuan; Ding, Chuan-Fan; Chu, Yan-Qiu; Zhou, Ping

2011-10-01

Curcumin has been recognized as a potential natural drug to treat the Alzheimer's disease (AD) by chelating baleful metal ions, scavenging radicals and preventing the amyloid β (Aβ) peptides from the aggregation. In this paper, Al(III)-curcumin complexes with Al(III) were synthesized and characterized by liquid-state 1H, 13C and 27Al nuclear magnetic resonance (NMR), mass spectroscopy (MS), ultraviolet spectroscopy (UV) and generalized 2D UV-UV correlation spectroscopy. In addition, the density functional theory (DFT)-based UV and chemical shift calculations were also performed to view insight into the structures and properties of curcumin and its complexes. It was revealed that curcumin could interact strongly with Al(III) ion, and form three types of complexes under different molar ratios of [Al(III)]/[curcumin], which would restrain the interaction of Al(III) with the Aβ peptide, reducing the toxicity effect of Al(III) on the peptide.

Detection of Nuclear Weapons and Materials: Science, Technologies, Observations

DTIC Science & Technology

2008-11-06

Nonproliferation Studies , 2004; Michael Levi, On Nuclear Terrorism, Cambridge, MA, Harvard University Press, 2007; and Carson Mark et al., “Can Terrorists Build...radiation and types of shielding. A DMOA study of real-world data found that the spectra from cargo differed between spring-summer and fall-winter; the study ...Algorithm and Resolution Studies ,” LLNL-TR-401531, December 31, 2007, by Padmini Sokkappa et al., pp. 21-22 This source is a report marked by Lawrence

Calcium-aluminum-rich inclusions with fractionation and unidentified nuclear effects (FUN CAIs): II. Heterogeneities of magnesium isotopes and 26Al in the early Solar System inferred from in situ high-precision magnesium-isotope measurements

NASA Astrophysics Data System (ADS)

Park, Changkun; Nagashima, Kazuhide; Krot, Alexander N.; Huss, Gary R.; Davis, Andrew M.; Bizzarro, Martin

2017-03-01

Calcium-aluminum-rich inclusions with isotopic mass fractionation effects and unidentified nuclear isotopic anomalies (FUN CAIs) have been studied for more than 40 years, but their origins remain enigmatic. Here we report in situ high precision measurements of aluminum-magnesium isotope systematics of FUN CAIs by secondary ion mass spectrometry (SIMS). Individual minerals were analyzed in six FUN CAIs from the oxidized CV3 carbonaceous chondrites Axtell (compact Type A CAI Axtell 2271) and Allende (Type B CAIs C1 and EK1-4-1, and forsterite-bearing Type B CAIs BG82DH8, CG-14, and TE). Most of these CAIs show evidence for excess 26Mg due to the decay of 26Al. The inferred initial 26Al/27Al ratios [(26Al/27Al)0] and the initial magnesium isotopic compositions (δ26Mg0) calculated using an exponential law with an exponent β of 0.5128 are (3.1 ± 1.6) × 10-6 and 0.60 ± 0.10‰ (Axtell 2271), (3.7 ± 1.5) × 10-6 and -0.20 ± 0.05‰ (BG82DH8), (2.2 ± 1.1) × 10-6 and -0.18 ± 0.05‰ (C1), (2.3 ± 2.4) × 10-5 and -2.23 ± 0.37‰ (EK1-4-1), (1.5 ± 1.1) × 10-5 and -0.42 ± 0.08‰ (CG-14), and (5.3 ± 0.9) × 10-5 and -0.05 ± 0.08‰ (TE) with 2σ uncertainties. We infer that FUN CAIs recorded heterogeneities of magnesium isotopes and 26Al in the CAI-forming region(s). Comparison of 26Al-26Mg systematics, stable isotope (oxygen, magnesium, calcium, and titanium) and trace element studies of FUN and non-FUN igneous CAIs indicates that there is a continuum among these CAI types. Based on these observations and evaporation experiments on CAI-like melts, we propose a generic scenario for the origin of igneous (FUN and non-FUN) CAIs: (i) condensation of isotopically normal solids in an 16O-rich gas of approximately solar composition; (ii) formation of CAI precursors by aggregation of these solids together with variable abundances of isotopically anomalous grains-possible carriers of unidentified nuclear (UN) effects; and (iii) melt evaporation of these precursors

Rock-Magnetic Method for Post Nuclear Detonation Diagnostics

NASA Astrophysics Data System (ADS)

Englert, J.; Petrosky, J.; Bailey, W.; Watts, D. R.; Tauxe, L.; Heger, A. S.

2011-12-01

A magnetic signature characteristic of a Nuclear Electromagnetic Pulse (NEMP) may still be detectable near the sites of atmospheric nuclear tests conducted at what is now the Nevada National Security Site. This signature is due to a secondary magnetization component of the natural remanent magnetization of material containing traces of ferromagnetic particles that have been exposed to a strong pulse of magnetic field. We apply a rock-magnetic method introduced by Verrier et al. (2002), and tested on samples exposed to artificial lightning, to samples of rock and building materials (e.g. bricks, concrete) retrieved from several above ground nuclear test sites. The results of magnetization measurements are compared to NEMP simulations and historic test measurements.

75 FR 16518 - Florida Power Corporation, et al.; Crystal River Unit 3 Nuclear Generating Plant; Exemption

Federal Register 2010, 2011, 2012, 2013, 2014

2010-04-01

... generically extend the rule's compliance date for all operating nuclear power plants, but noted that the..., Nuclear Energy Institute). The licensee's request for an exemption is therefore consistent with the... of this exemption will not have a significant effect on the quality of the human environment (75 FR...

75 FR 70953 - Florida Power Corporation, et al.; Crystal River Unit 3 Nuclear Generating Plant; Exemption

Federal Register 2010, 2011, 2012, 2013, 2014

2010-11-19

... rule's compliance date for all operating nuclear power plants, but noted that the Commission's... compliance date (Reference: June 4, 2009, letter from R. W. Borchardt, NRC, to M. S. Fertel, Nuclear Energy... Commission (NRC, the Commission) now or hereafter in effect. The facility consists of one pressurized-water...

Synthesizing (ZrAl3 + AlN)/Mg-Al composites by a 'matrix exchange' method

NASA Astrophysics Data System (ADS)

Gao, Tong; Li, Zengqiang; Hu, Kaiqi; Han, Mengxia; Liu, Xiangfa

2018-06-01

A method named 'matrix exchange' to synthesize ZrAl3 and AlN reinforced Mg-Al composite was developed in this paper. By inserting Al-10ZrN master alloy into Mg matrix and reheating the cooled ingot to 550 °C, Al and Mg atoms diffuse to the opposite side. As a result, liquid melt occurs once the interface areas reach to proper compositions. Then dissolved Al atoms react with ZrN, leading to the in-situ formation of ZrAl3 and AlN particles, while the Al matrix is finally replaced by Mg. This study provides a new insight for preparing Mg composites.

The Healthy Worker Effect and Nuclear Industry Workers

PubMed Central

Fornalski, Krzysztof W.; Dobrzyński, Ludwik

2010-01-01

The linear no-threshold (LNT) dose-effect relationship has been consistently used by most radiation epidemiologists to estimate cancer mortality risk. The large scattering of data by International Agency for Research on Cancer, IARC (Vrijheid et al. 2007; Therry-Chef et al. 2007; Cardis et al. 2007), interpreted in accordance with LNT, has been previously demonstrated (Fornalski and Dobrzyński 2009). Using conventional and Bayesian methods the present paper demonstrates that the standard mortality ratios (SMRs), lower in the IARC cohort of exposed nuclear workers than in the non exposed group, should be considered as a hormetic effect, rather than a healthy worker effect (HWE) as claimed by the IARC group. PMID:20585442

Antiferromagnetic spin fluctuations and unconventional nodeless superconductivity in an iron-based new superconductor (Ca4Al2O(6-y))(Fe2As2): 75As nuclear quadrupole resonance study.

PubMed

Kinouchi, H; Mukuda, H; Yashima, M; Kitaoka, Y; Shirage, P M; Eisaki, H; Iyo, A

2011-07-22

We report 75As nuclear quadrupole resonance studies on (Ca4Al2O(6-y))(Fe2As2) with T(c) = 27  K. Measurement of nuclear-spin-relaxation rate 1/T1 has revealed a significant development of two-dimensional antiferromagnetic spin fluctuations down to T(c) in association with the smallest As-Fe-As bond angle. Below T(c), the temperature dependence of 1/T1 without any trace of the coherence peak is well accounted for by a nodeless s(±)-wave multiple-gaps model. From the fact that its T(c) is comparable to T(c) = 28  K in the optimally doped LaFeAsO(1-y) in which antiferromagnetic spin fluctuations are not dominant, we remark that antiferromagnetic spin fluctuations are not a unique factor for enhancing T(c) among Fe-based superconductors, but a condition for optimizing superconductivity should be addressed from the lattice structure point of view.

Nuclear Data Sheets for A=36

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nica N.; Nica,N.; Cameron,J.

2012-01-01

Nuclear spectroscopic information for experimentally investigated nuclides of mass 36 (Mg, Al, Si, P, S, Cl, Ar, K, Ca) has been evaluated. The principal sources of the 'adopted levels' presented for nuclides close to the stability line are Endt's evaluations (1990En08, 1978En02). The data sets for reactions and decays, including all available gamma-ray data, are based mostly on the original literature. The {sup 36}Na has been looked for but not yet experimentally detected. There are no data available for the excited states in {sup 36}Al, and for {sup 36}Mg and {sup 36}Ca, only one excited state is known.

Al-26 from red giants. [connections with anomalous Mg-26 content in meteorites and solar system formation

NASA Technical Reports Server (NTRS)

Norgaard, H.

1980-01-01

Simplified models of thermally pulsing red giants are investigated, with particular emphasis on predicting the extent to which nuclear processing at the base of the convective envelope in conjunction with processing in the thermally unstable He shell can synthesize Al-26 (tau/1/2/ = 7.2 x 10 to the 5th yr). Values of Al-26/Al-27 of about 0.5-1, with Al-27/Al-27(solar) of about 1-2, are predicted in some cases. It is pointed out that such results can lead to isotope shifts in the absorption lines of AlH and AlO, which should be observationally identifiable in some late-type supergiants. The possible connection with the anomalous Mg-26 content (assigned to the decay of Al-26) detected in some meteorites and the connection with formation of the solar system are also touched on.

The Analysis of the General Performance and Mechanical Behavior of Unirradiated FeCrAl Alloys Before and After Welding

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gussev, Maxim N.; Field, Kevin G.; Yamamoto, Yukinori

2016-06-03

The present report summarizes and discusses the preliminary results for the in-depth characterization of the modern, nuclear-grade FeCrAl alloys currently under development. The alloys were designed for enhanced radiation tolerance and weldability, and the research is currently being pursued by the Department of Energy (DOE) Nuclear Energy Enabling Technologies (NEET) program. Last year, seven candidate FeCrAl alloys with well-controlled chemistry and microstructures were designed and produced; welding was performed under well-controlled conditions. The structure and general performance of unirradiated alloys were assessed using standardized and advanced microstructural characterization techniques and mechanical testing. The primary objective is to identify the bestmore » candidate alloy, or at a minimum to identify the contributing factors that increase the weldability and radiation tolerance of FeCrAl alloys, therefore enabling future generations of FeCrAl alloys to deliver better performance parameters. This report is structured so as to describe these critical assessments of the weldability; radiation tolerance will be reported on in later reports from this program.« less

Converting point-wise nuclear cross sections to pole representation using regularized vector fitting

NASA Astrophysics Data System (ADS)

Peng, Xingjie; Ducru, Pablo; Liu, Shichang; Forget, Benoit; Liang, Jingang; Smith, Kord

2018-03-01

Direct Doppler broadening of nuclear cross sections in Monte Carlo codes has been widely sought for coupled reactor simulations. One recent approach proposed analytical broadening using a pole representation of the commonly used resonance models and the introduction of a local windowing scheme to improve performance (Hwang, 1987; Forget et al., 2014; Josey et al., 2015, 2016). This pole representation has been achieved in the past by converting resonance parameters in the evaluation nuclear data library into poles and residues. However, cross sections of some isotopes are only provided as point-wise data in ENDF/B-VII.1 library. To convert these isotopes to pole representation, a recent approach has been proposed using the relaxed vector fitting (RVF) algorithm (Gustavsen and Semlyen, 1999; Gustavsen, 2006; Liu et al., 2018). This approach however needs to specify ahead of time the number of poles. This article addresses this issue by adding a poles and residues filtering step to the RVF procedure. This regularized VF (ReV-Fit) algorithm is shown to efficiently converge the poles close to the physical ones, eliminating most of the superfluous poles, and thus enabling the conversion of point-wise nuclear cross sections.

Mechanical properties of neutron-irradiated model and commercial FeCrAl alloys

DOE PAGES

Field, Kevin G.; Briggs, Samuel A.; Sridharan, Kumar; ...

2017-03-28

The development and understanding of the mechanical properties of neutron-irradiated FeCrAl alloys is increasingly a critical need as these alloys continue to become more mature for nuclear reactor applications. This study focuses on the mechanical properties of model FeCrAl alloys and of a commercial FeCrAl alloy neutron-irradiated to up to 13.8 displacements per atom (dpa) at irradiation temperatures between 320 and 382 °C. Tensile tests were completed at room temperature and at 320 °C, and a subset of fractured tensile specimens was examined by scanning electron microscopy. Results showed typical radiation hardening and embrittlement indicative of high chromium ferritic alloysmore » with strong chromium composition dependencies at lower doses. At and above 7.0 dpa, the mechanical properties saturated for both the commercial and model FeCrAl alloys, although brittle cleavage fracture was observed at the highest dose in the model FeCrAl alloy with the highest chromium content (18 wt %). Finally, the results suggest the composition and microstructure of FeCrAl alloys plays a critical role in the mechanical response of FeCrAl alloys irradiated near temperatures relevant to light water reactors.« less

[The language of medicine as presented in the references of original articles published in Medicina Clínica for 50 years (1945-1995)].

PubMed

Navarro, F A

1996-11-09

To describe and analyse the frequency of the various languages in the bibliographical references from the original articles published in MEDICINA CLINICA during the past 50 years (1945-1995). The languages of publication of 12,807 references from 540 original works published in MEDICINA CLINICA between 1945 and 1995 were determined (at the rate of near 50 articles per year at intervals of five years). The percentage of references in English increased constantly until 1980, but has decreased since then (26.3% in 1945, 42.1% in 1995, 57.7% in 1970, 84.2% in 1980 and 78.5% in 1995). In contrast, the percentage of references in Spanish decreased until 1980, but has increased since then (27.4% in 1945, 18.4% in 1955, 15.8% in 1970, 8.1% in 1980 and 20.0% in 1995). Initially the percentage of references in French remained more or less constant, but decreased markedly from 1970 on ward (23.1% in 1945, 22.5% in 1955, 17.1% in 1970, 5.9% in 1980 and 0.5% in 1995). The percentage of references in German decreased almost continuously during the whole period studied (19.6% in 1945, 10.7% in 1955, 5.8% in 1970, 0.3% in 1980 and 0.3% also in 1995). In 1965, English became the undisputed language of medicine in Spain. The importance of English increased from 1945, then stabilised and even started to decrease in 1980. The importance of Spanish has evolved inversely to that of English, decreasing until 1980 and increasing since that time. The importance of French remained stable until 1970, since when it has decreased, although it continued to be mentioned relatively frequently until 1990. The importance of German decreased constantly from 1945, until this language almost completely disappeared from 1985 onward.

Heterogeneous dislocation loop formation near grain boundaries in a neutron-irradiated commercial FeCrAl alloy

DOE PAGES

Field, Kevin G.; Briggs, Samuel A.; Hu, Xunxiang; ...

2016-11-01

FeCrAl alloys are an attractive materials class for nuclear power applications due to their increased environmental compatibility over more traditional nuclear materials. Preliminary studies into the radiation tolerance of FeCrAl alloys under accelerated neutron testing between 300-400 °C have shown post-irradiation microstructures containing dislocation loops and Cr-rich ' phase. Although these initial works established the post-irradiation microstructures, little to no focus was applied towards the influence of pre-irradiation microstructures on this response. Here, a well annealed commercial FeCrAl alloy, Alkrothal 720, was neutron irradiated to 1.8 dpa at 382 °C and then the role of random high angle grain boundariesmore » on the spatial distribution and size of dislocation loops, dislocation loops, and black dot damage was analyzed using on-zone scanning transmission electron microscopy. Results showed a clear heterogeneous dislocation loop formation with dislocation loops showing an increased number density and size, black dot damage showing a significant number density decrease, and an increased size of dislocation loops in the vicinity directly adjacent to the grain boundary. Lastly, these results suggest the importance of the pre-irradiation microstructure on the radiation tolerance of FeCrAl alloys.« less

Lattice damage assessment and optical waveguide properties in LaAlO3 single crystal irradiated with swift Si ions

NASA Astrophysics Data System (ADS)

Liu, Y.; Crespillo, M. L.; Huang, Q.; Wang, T. J.; Liu, P.; Wang, X. L.

2017-02-01

As one of the representative ABO3 perovskite-structured oxides, lanthanum aluminate (LaAlO3) crystal has emerged as one of the most valuable functional-materials, and has attracted plenty of fundamental research and promising applications in recent years. Electronic, magnetic, optical and other properties of LaAlO3 strongly depend on its crystal structure, which could be strongly modified owing to the nuclear or electronic energy loss deposited in an ion irradiation environment and, therefore, significantly affecting the performance of LaAlO3-based devices. In this work, utilizing swift (tens of MeV) Si-ion irradiation, the damage behavior of LaAlO3 crystal induced by nuclear or electronic energy loss has been studied in detail utilizing complementary characterization techniques. Differing from other perovskite-structured crystals in which the electronic energy loss could lead to the formation of an amorphous region based on the thermal spike mechanism, in this case, intense electronic energy loss in LaAlO3 will not induce any obvious structural damage. The effects of ion irradiation on the mechanical properties, including hardness increase and elastic modulus decrease, have been confirmed. On the other hand, considering the potential applications of LaAlO3 in the field of integrated optoelectronics, the optical-waveguide properties of the irradiation region have been studied. The significant correspondence (symmetrical inversion) between the iWKB-reconstructed refractive-index profile and SRIM-simulated dpa profile further proves the effects (irradiation-damage production and refractive-index decrease) of nuclear energy loss during the swift-ion penetration process in LaAlO3 crystal. In the case of the rather-thick damage layer produced by swift-ion irradiation, obtaining a damage profile will be constrained owing to the analysis-depth limitation of the characterization techniques (RBS/channeling), and our analysis process (optical guided-mode measurement and

Nuclear Fusion prize laudation Nuclear Fusion prize laudation

NASA Astrophysics Data System (ADS)

Burkart, W.

2011-01-01

Clean energy in abundance will be of critical importance to the pursuit of world peace and development. As part of the IAEA's activities to facilitate the dissemination of fusion related science and technology, the journal Nuclear Fusion is intended to contribute to the realization of such energy from fusion. In 2010, we celebrated the 50th anniversary of the IAEA journal. The excellence of research published in the journal is attested to by its high citation index. The IAEA recognizes excellence by means of an annual prize awarded to the authors of papers judged to have made the greatest impact. On the occasion of the 2010 IAEA Fusion Energy Conference in Daejeon, Republic of Korea at the welcome dinner hosted by the city of Daejeon, we celebrated the achievements of the 2009 and 2010 Nuclear Fusion prize winners. Steve Sabbagh, from the Department of Applied Physics and Applied Mathematics, Columbia University, New York is the winner of the 2009 award for his paper: 'Resistive wall stabilized operation in rotating high beta NSTX plasmas' [1]. This is a landmark paper which reports record parameters of beta in a large spherical torus plasma and presents a thorough investigation of the physics of resistive wall mode (RWM) instability. The paper makes a significant contribution to the critical topic of RWM stabilization. John Rice, from the Plasma Science and Fusion Center, MIT, Cambridge is the winner of the 2010 award for his paper: 'Inter-machine comparison of intrinsic toroidal rotation in tokamaks' [2]. The 2010 award is for a seminal paper that analyzes results across a range of machines in order to develop a universal scaling that can be used to predict intrinsic rotation. This paper has already triggered a wealth of experimental and theoretical work. I congratulate both authors and their colleagues on these exceptional papers. W. Burkart Deputy Director General Department of Nuclear Sciences and Applications International Atomic Energy Agency, Vienna

75 FR 31477 - Southern Nuclear Operating Company, et al; Notice of Consideration of Issuance of Amendment to...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-03

... seismic analyses of the Nuclear Island (NI). Reclassifying backfill over the slopes of the excavation does... to define the VEGP GMRS and FIRS or the VEGP SASSI SSI seismic analyses of the Nuclear Island (NI...

Viability and molecular authentication of Coccidioides spp. isolates from the Instituto de Medicina Tropical de São Paulo culture collection, Brazil.

PubMed

Cavalcanti, Sarah Desirée Barbosa; Vidal, Mônica Scarpelli Martinelli; Sousa, Maria da Glória Teixeira de; Del Negro, Gilda Maria Barbaro

2013-01-01

Coccidioidomycosis is an emerging fungal disease in Brazil; adequate maintenance and authentication of Coccidioides isolates are essential for research into genetic diversity of the environmental organisms, as well as for understanding the human disease. Seventeen Coccidioides isolates maintained under mineral oil since 1975 in the Instituto de Medicina Tropical de São Paulo (IMTSP) culture collection, Brazil, were evaluated with respect to their viability, morphological characteristics and genetic features in order to authenticate these fungal cultures. Only five isolates were viable after almost 30 years, showing typical morphological characteristics, and sequencing analysis using Coi-F and Coi-R primers revealed 99% identity with Coccidioides genera. These five isolates were then preserved in liquid nitrogen and sterile water, and remained viable after two years of storage under these conditions, maintaining the same features.

Autophagy Devours the Nuclear Lamina to Thwart Oncogenic Stress.

PubMed

Leidal, Andrew M; Debnath, Jayanta

2015-12-07

A recent study by Dou et al. (2015) in Nature extends the functions of autophagy to the nucleus, where it mediates the degradation of the nuclear lamina upon oncogenic insults to reinforce cellular senescence. Copyright © 2015 Elsevier Inc. All rights reserved.

Aluminum Solubility Mechanisms in Quartz: Implications for Al-in-Quartz Thermobarometry

NASA Astrophysics Data System (ADS)

Was, E.; Thomas, J. B.; Nachlas, W. O.

2016-12-01

Trace element thermobarometers in minerals are becoming increasingly important tools for studying geologic processes in many different geologic environments. The solubility of some trace-level (i.e. <1000 ppmw) components in minerals can be measured and used to estimate the pressure (P) and/or temperature (T) of mineral crystallization. To date, quartz has been useful for trace element thermobarometry (based on its Ti content) due to its common occurrence in many rock types and therefore can provide information on a wide range of petrologic processes. However, this technique relies on an independent constraint on T (or P) to calculate P (or T), which can be difficult to obtain in some rocks. To add to the utility of quartz as a thermobarometer, we have experimentally co-crystallized quartz and aluminosilicates at elevated P-T conditions to determine Al solubilities in quartz, which will allow use of the crossing isopleths method to determine a unique P and T solution from two independent techniques (using Ti and Al) in the same mineral. Preliminary experiments demonstrate that Al concentrations in quartz vary systematically with P and T, and also show that Al is soluble at greater levels than Ti. The success of an Al-in-quartz thermobarometer relies on determining both the variations in Al solubility across P-T space as well as the solubility mechanism for Al substitution into the quartz structure. To determine these parameters, we use Fourier transform infrared spectroscopy (FTIR) to quantify H+ contents as a charge-balancing ion for Al3+ to replace Si4+, electron microprobe (EPMA) to measure Al concentrations, and nuclear magnetic resonance spectroscopy (NMR) to determine the coordination environment of Al in quartz.

Classical-Nova Contribution to the Milky Way’s Al 26 Abundance: Exit Channel of the Key Al 25 ( p , γ ) Si 26 Resonance

DOE PAGES

Bennett, M. B.; Wrede, C.; Chipps, K. A.; ...

2013-12-04

We present that classical novae are expected to contribute to the 1809-keV Galactic γ-ray emission by producing its precursor 26Al, but the yield depends on the thermonuclear rate of the unmeasured 25Al(p,γ) 26Si reaction. Using the β decay of 26P to populate the key J π=3 + resonance in this reaction, we report the first evidence for the observation of its exit channel via a 1741.6±0.6(stat)±0.3(syst) keV primary γ ray, where the uncertainties are statistical and systematic, respectively. By combining the measured γ-ray energy and intensity with other experimental data on 26Si, we find the center-of-mass energy and strength of the resonance to be E r=414.9±0.6(stat)±0.3(syst)±0.6(lit.) keV and ωγ=23±6(stat)more » $$+11\\atop{-10}$$(lit.) meV, respectively, where the last uncertainties are from adopted literature data. Finally, we use hydrodynamic nova simulations to model 26Al production showing that these measurements effectively eliminate the dominant experimental nuclear-physics uncertainty and we estimate that novae may contribute up to 30% of the Galactic 26Al.« less

Magnetism of Al-substituted magnetite reduced from Al-hematite

NASA Astrophysics Data System (ADS)

Jiang, Zhaoxia; Liu, Qingsong; Zhao, Xiang; Roberts, Andrew P.; Heslop, David; Barrón, Vidal; Torrent, José

2016-06-01

Aluminum-substituted magnetite (Al-magnetite) reduced from Al-substituted hematite or goethite (Al-hematite or Al-goethite) is an environmentally important constituent of magnetically enhanced soils. In order to characterize the magnetic properties of Al-magnetite, two series of Al-magnetite samples were synthesized through reduction of Al-hematite by a mixed gas (80% CO2 and 20% CO) at 395°C for 72 h in a quartz tube furnace. Al-magnetite samples inherited the morphology of their parent Al-hematite samples, but only those transformed from Al-hematite synthesized at low temperature possessed surficial micropores, which originated from the release of structural water during heating. Surface micropores could thus serve as a practical fingerprint of fire or other high-temperature mineralogical alteration processes in natural environments, e.g., shear friction in seismic zones. In addition, Al substitution greatly affects the magnetic properties of Al-magnetite. For example, coercivity (Bc) increases with increasing Al content and then decreases slightly, while the saturation magnetization (Ms), Curie temperature (Tc), and Verwey transition temperature (Tv) all decrease with increasing Al content due to crystal defect formation and dilution of magnetic ions caused by Al incorporation. Moreover, different trends in the correlation between Tc and Bc can be used to discriminate titanomagnetite from Al-magnetite, which is likely to be important in environmental and paleomagnetic studies, particularly in soil.

EVN e-VLBI detections of MAXI J1659-152

NASA Astrophysics Data System (ADS)

Paragi, Z.; van der Horst, A. J.; Granot, J.; Taylor, G. B.; Kouveliotou, C.; Garrett, M. A.; Wijers, R. A. M. J.; Ramirez-Ruiz, E.; Kuulkers, E.; Gehrels, N.; Woods, P. M.

2010-10-01

We observed MAXI J1659-152 (Negoro et al. 2010, ATel #2873; Mangano et al. 2010, GCN #11296) following its sub-millimeter and centimeter radio detections (de Ugarte Postigo et al. 2010, GCN #11304; van der Horst et al. 2010, ATel #2874) with the European VLBI Network (EVN) in real-time e-VLBI mode on 30 September 2010, from 13:30 to 18:30 UT at 4.9 GHz. The participating telescopes were Cambridge, Effelsberg, Jodrell Bank (MkII), Hartebeesthoek, Medicina, Onsala, Torun and Westerbork sending data at a rate of ~1024 Mbps to the EVN Data Processor at JIVE.

Familial ALS

PubMed Central

Boylan, Kevin

2015-01-01

Synopsis Genes linked to ALS susceptibility are being identified at an increasing rate owing to advances in molecular genetic technology. Genetic mechanisms in ALS pathogenesis appear to exert major effects in ~10% of patients, but genetic factors at some level may be important components of disease risk in most ALS patients. Identification of gene variants associated with ALS has informed concepts of the pathogenesis of ALS, aided the identification of therapeutic targets, facilitated research to develop new ALS biomarkers, and supported the establishment of clinical diagnostic tests for ALS-linked genes. Translation of this knowledge to ALS therapy development is ongoing. PMID:26515623

The climatic effects of nuclear war

NASA Technical Reports Server (NTRS)

Turco, R. P.; Toon, O. B.; Ackerman, T. P.; Pollack, J. B.; Sagan, C.

1984-01-01

The effects of various US-USSR nuclear-exchange scenarios on global climate are investigated by means of computer simulations, summarizing the results of Turco et al. (1983) and follow-up studies using 3D global-circulation models. A nuclear-scenario model is used to determine the amounts of dust, smoke, radioactivity, and pyrotoxins generated by a particular type of nuclear exchange (such as a general 5,000-Mt exchange, a 1,000-Mt limited exchange, a 5,000-Mt hard-target counterforce attack, and a 100-Mt attack on cities only): a particle-microphysics model predicts the evolution of the dust and smoke particles; and a radiative-convective climate model estimates the effects of the dust and smoke clouds on the global radiation budget. The findings are presented in graphs, diagrams, and a table. Thick clouds blocking most sunlight over the Northern Hemisphere midlatitudes for weeks or months and producing ground-temperature reductions of 20-40 C, disruption of global circulation patterns, and rapid spread of clouds to the Southern Hemisphere are among the 'nuclear-winter' effects predicted for the 5,000-Mt baseline case. The catastrophic consequences for plant, animal, and human populations are considered, and the revision of superpower nuclear strategies is urged.

Ab initio modeling of zincblende AlN layer in Al-AlN-TiN multilayers

DOE PAGES

Yadav, S. K.; Wang, J.; Liu, X. -Y.

2016-06-13

An unusual growth mechanism of metastable zincblende AlN thin film by diffusion of nitrogen atoms into Al lattice is established. Using first-principles density functional theory, we studied the possibility of thermodynamic stability of AlN as a zincblende phase due to epitaxial strains and interface effect, which fails to explain the formation of zincblende AlN. We then compared the formation energetics of rocksalt and zincblende AlN in fcc Al through direct diffusion of nitrogen atoms to Al octahedral and tetrahedral interstitials. Furthermore, the formation of a zincblende AlN thin film is determined to be a kinetically driven process, not a thermodynamicallymore » driven process.« less

Submission of FeCrAl Feedstock for Support of AFC ATR-2 Irradiations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Field, Kevin G.; Barrett, Kristine E.; Sun, Zhiqian

The Advanced Test Reactor (ATR) is currently being used to test accident tolerant fuel (ATF) forms destined for commercial nuclear power plant deployment. One irradiation program using the ATR for ATF concepts, Accident Tolerant Fuel-2 (ATF-2), is a water loop irradiation test using miniaturized fuel pins as test articles. This complicated testing configuration requires a series of pre-test experiments and verification including a flowing loop autoclave test and a sensor qualification test (SQT) prior to full test train deployment within the ATR. In support of the ATF-2 irradiation program, Oak Ridge National Laboratory (ORNL) has supplied two different Generation IImore » FeCrAl alloys in rod stock form to Idaho National Laboratory (INL). These rods will be machined into dummy pins for deployment in the autoclave test and SQT. Post-test analysis of the dummy pins will provide initial insight into the performance of Generation II FeCrAl alloys in the ATF-2 irradiation experiment as well as within a commercial nuclear reactor.« less

Interfacial characterization of Al-Al thermocompression bonds

DOE Office of Scientific and Technical Information (OSTI.GOV)

Malik, N., E-mail: nishantmalik1987@gmail.com; SINTEF ICT, Department of Microsystems and Nanotechnology, P.O. Box 124 Blindern, N-0314 Oslo; Carvalho, P. A.

2016-05-28

Interfaces formed by Al-Al thermocompression bonding were studied by the transmission electron microscopy. Si wafer pairs having patterned bonding frames were bonded using Al films deposited on Si or SiO{sub 2} as intermediate bonding media. A bond force of 36 or 60 kN at bonding temperatures ranging from 400–550 °C was applied for a duration of 60 min. Differences in the bonded interfaces of 200 μm wide sealing frames were investigated. It was observed that the interface had voids for bonding with 36 kN at 400 °C for Al deposited both on Si and on SiO{sub 2}. However, the dicing yield was 33% for Al onmore » Si and 98% for Al on SiO{sub 2}, attesting for the higher quality of the latter bonds. Both a bond force of 60 kN applied at 400 °C and a bond force of 36 kN applied at 550 °C resulted in completely bonded frames with dicing yields of, respectively, 100% and 96%. A high density of long dislocations in the Al grains was observed for the 60 kN case, while the higher temperature resulted in grain boundary rotation away from the original Al-Al interface towards more stable configurations. Possible bonding mechanisms and reasons for the large difference in bonding quality of the Al films deposited on Si or SiO{sub 2} are discussed.« less

Heterogeneous dislocation loop formation near grain boundaries in a neutron-irradiated commercial FeCrAl alloy

NASA Astrophysics Data System (ADS)

Field, Kevin G.; Briggs, Samuel A.; Hu, Xunxiang; Yamamoto, Yukinori; Howard, Richard H.; Sridharan, Kumar

2017-01-01

FeCrAl alloys are an attractive class of materials for nuclear power applications because of their increased environmental compatibility compared with more traditional nuclear materials. Preliminary studies into the radiation tolerance of FeCrAl alloys under accelerated neutron testing between 300 and 400 °C have shown post-irradiation microstructures containing dislocation loops and a Cr-rich α‧ phase. Although these initial studies established the post-irradiation microstructures, there was little to no focus on understanding the influence of pre-irradiation microstructures on this response. In this study, a well-annealed commercial FeCrAl alloy, Alkrothal 720, was neutron irradiated to 1.8 displacements per atom (dpa) at 382 °C and then the effect of random high-angle grain boundaries on the spatial distribution and size of a〈100〉 dislocation loops, a/2〈111〉 dislocation loops, and black dot damage was analyzed using on-zone scanning transmission electron microscopy. Results showed a clear heterogeneous dislocation loop formation with a/2〈111〉 dislocation loops showing an increased number density and size, black dot damage showing a significant number density decrease, and a〈100〉 dislocation loops exhibiting an increased size in the vicinity of the grain boundary. These results suggest the importance of the pre-irradiation microstructure and, specifically, defect sink density spacing to the radiation tolerance of FeCrAl alloys.

The 26gAl(p,g)27Si reaction in Novae

NASA Astrophysics Data System (ADS)

Ruiz, Chris; Parikh, A.; José, J.; Buchmann, L.; Caggiano, J. A.; Chen, A. A.; Clark, J. A.; Crawford, H.; Davids, B.; D'Auria, J. M.; Davis, C.; Deibel, C.; Erikson, L.; Fogarty, L.; Frekers, D.; Greife, U.; Hussein, A.; Hutcheon, D. A.; Huyse, M.; Jewett, C.; Laird, A. M.; Lewis, R.; Mumby-Croft, P.; Olin, A.; Ottewell, D. F.; Ouellet, C. V.; Parker, P.; Pearson, J.; Ruprecht, G.; Trinczek, M.; Vockenhuber, C.; Wrede, C.

The 26gAl(p,γ)27Si Reaction in Novae PoS(NIC-IX)004 1 TRIUMF, 4004 Wesbrook Mall, Vancouver, BC V6T 2A3, Canada 2 Wright Nuclear Structure Laboratory, Yale University, New Haven, Conneticut 06520-8124, USA 3 Dept. de Física í Enginyeria Nuclear, Universitat Politécnica de Catalunya, Barcelona, Spain 4 Institut d'Estudis Espacials de Catalunya (IEEC), Barcelona, Spain 5 McMaster University, Hamilton, ON L8S 481, Canada 6 Simon Fraser University, Burnaby, BC V5A 1S6, Canada 7 Department of Physics, Colorado School of Mines, Golden, Colorado 80401, USA 8 National University of Ireland, Maynooth, Co. Kildare, Ireland 9 Institut für Kernphysik, Westfälische Willhelms-Universität Münster, 48149 Münster, Germany 10 University of Northern British Columbia, Prince George, BC V2N 4Z9, Canada 11 Katholieke Universiteit Leuven, 3000 Leuven, Belgium 12 Department of Physics, University of York, York YO10 5DD, United Kingdom The 184 keV resonance strength in the 26gAl(p,γ)27Si reaction was measured in inverse kinematics using the DRAGON facility at TRIUMF-ISAC. We obtain a value of ωγ=35±7 μeV for the strength and ER=184±1 keV for the resonance energy. These values are consistent with p-wave capture into the 7652(3) keV state in 27Si. We discuss the implications of these results for 26gAl nucleosynthesis in a typical O-Ne white dwarf nova.

[The chapter De Puero virgine (or de homine) of Liber medicinae ex animalibus by Sextus Placidus. Historical study, new critical edition and translation].

PubMed

Ferraces Rodríguez, Arsenio

2012-01-01

The article offers an historical study, a new critical edition and the translation of the chapter De Puero virgine of Liber medicinae ex animalibus by Sextus Placitus, firstly edited by Sigerist and Howald in 1927. The book, dating to Late Antiquity, is part of a phyto -zootherapeutical corpus, trasmitted by the manuscript tradition in a single block of text whose central axis is represented by the Herbarium by Pseudo-Apuleius, the tractatus De herba vettonica attributed to Antonius Musa and the De taxone. Chapter 17 is devoted to pharmacological recipes whose ingredients are organic or human body parts; here is provided a critical edition based on the collation of three texts in the manuscript tradition, well testifying the particular vitality of medical prescription texts in Late Antiquity.

76 FR 77023 - In the Matter of Florida Power Corporation, et al., Crystal River Unit 3 Nuclear Generating Plant...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-12-09

... the Nuclear Regulatory Commission (NRC, the Commission) consent to the proposed indirect transfer of... transfer action, FPC shall inform the Director of the Office of Nuclear Reactor Regulation in writing of... NUCLEAR REGULATORY COMMISSION [NRC-2011-0281; License No. DPR-72; Docket No. 50-302] In the Matter...

Thermal Modeling of Al-Al and Al-Steel Friction Stir Spot Welding

NASA Astrophysics Data System (ADS)

Jedrasiak, P.; Shercliff, H. R.; Reilly, A.; McShane, G. J.; Chen, Y. C.; Wang, L.; Robson, J.; Prangnell, P.

2016-09-01

This paper presents a finite element thermal model for similar and dissimilar alloy friction stir spot welding (FSSW). The model is calibrated and validated using instrumented lap joints in Al-Al and Al-Fe automotive sheet alloys. The model successfully predicts the thermal histories for a range of process conditions. The resulting temperature histories are used to predict the growth of intermetallic phases at the interface in Al-Fe welds. Temperature predictions were used to study the evolution of hardness of a precipitation-hardened aluminum alloy during post-weld aging after FSSW.

Nuclear Testing and National Security,

DTIC Science & Technology

1981-01-01

ests, even though we have promised for years to begin nuclear dis- armament in the particular way represented by a CTB. More rational is the proposition...when Harold Stassen was Eisenhower’s selection to head a special White House group to formulate US dis- armament policy, we have been wrapped up in a...desired "personal incentive not to deny" their negotiated agreements Is perhaps the most ration - al explanation yet advanced. isi .. .. . n mI The

Proton irradiation studies on Al and Al5083 alloy

NASA Astrophysics Data System (ADS)

Bhattacharyya, P.; Gayathri, N.; Bhattacharya, M.; Gupta, A. Dutta; Sarkar, Apu; Dhar, S.; Mitra, M. K.; Mukherjee, P.

2017-10-01

The change in the microstructural parameters and microhardness values in 6.5 MeV proton irradiated pure Al and Al5083 alloy samples have been evaluated using different model based techniques of X-ray diffraction Line Profile Analysis (XRD) and microindendation techniques. The detailed line profile analysis of the XRD data showed that the domain size increases and saturates with irradiation dose both in the case of Al and Al5083 alloy. The corresponding microstrain values did not show any change with irradiation dose in the case of the pure Al but showed an increase at higher irradiation doses in the case of Al5083 alloy. The microindendation results showed that unirradiated Al5083 alloy has higher hardness value compared to that of unirradiated pure Al. The hardness increased marginally with irradiation dose in the case of Al5083, whereas for pure Al, there was no significant change with dose.

Can Cr( iii ) substitute for Al( iii ) in the structure of boehmite?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chatterjee, Sayandev; Conroy, Michele A.; Smith, Frances N.

2016-01-01

The dissolution of boehmite is a technical issue for the Al industry because of its recalcitrant nature. In fact, a similar problem exists with boehmite in nuclear waste sludge at the Hanford site in eastern Washington State, USA. Dissolution of Al phases is required to reduce the waste loadings in the final borosilicate glass waste form. Although not the most common Al-bearing species in the sludge, boehmite may become a rate limiting step in the processing of the wastes. Hanford boehmite is an order of magnitude more resistant to dissolution in hot caustic solutions than expected from surface-normalized rates. Wemore » are exploring potential intrinsic and extrinsic effects that may limit boehmite reactivity; one clue comes from microstructural analyses that indicate an association of Cr with Al in the Hanford nuclear waste. Hence, in this first paper, we investigated the potential role of chromium on the reactivity of boehmite in caustic solution. An important finding was that irrespective of the synthesis pathway, amount of Cr(III), or the resultant morphology, there was no evidence for Cr incorporation in the bulk structure, in agreement with QM calculations. In fact, electron microscopic (EM) and spectroscopic analyses showed that Cr was enriched at the (101) edges of the boehmite. However, Cr had no measurable effect on the morphology during the synthesis step. In contrast, comparison of the morphologies of the synthetic Cr-doped and pure boehmite samples after exposure to caustic solutions provided evidence that Cr inhibited the corrosion. TEM showed that Cr was not homogeneously distributed at the surface. Consequently, Cr may have partially passivated the surface by blocking discrete energetic sites on the lateral surfaces of boehmite.« less

Summary documentation of LASL nuclear data evaluations for ENDF/B-V

DOE Office of Scientific and Technical Information (OSTI.GOV)

Young, P.G.

1979-01-01

Summaries are presented of nuclear data evaluations performed at Los Alamos Scientific Laboratory (LASL) that will comprise part of Version V of the Evaluated Nuclear Data File, ENDF/B. A total of 18 general purpose evaluations of neutron-induced data are summarized, together with 6 summaries directed specifically at covariance data evaluations. The general purpose evaluation summaries cover the following isotopes: /sup 1 -3/H, /sup 3/ /sup 4/He, /sup 6/ /sup 7/Li, /sup 10/B, /sup 14/ /sup 15/N, /sup 16/O, /sup 27/Al, /sup 182/ /sup 183/ /sup 184/ /sup 186/W, /sup 233/U, and /sup 242/Pu. The covariance data summaries are given formore » /sup 1/H, /sup 6/Li, /sup 10/B, /sup 14/N, /sup 16/O, and /sup 27/Al. 28 figures.« less

Radiation tolerance of neutron-irradiated model Fe-Cr-Al alloys

DOE PAGES

Field, Kevin G.; Hu, Xunxiang; Littrell, Kenneth C.; ...

2015-07-14

The Fe Cr Al alloy system has the potential to form an important class of enhanced accident-tolerant cladding materials in the nuclear power industry owing to the alloy system's higher oxidation resistance in high-temperature steam environments compared with traditional zirconium-based alloys. However, radiation tolerance of Fe Cr Al alloys has not been fully established. In this study, a series of Fe Cr Al alloys with 10 18 wt % Cr and 2.9 4.9 wt % Al were neutron irradiated at 382 C to 1.8 dpa to investigate the irradiation-induced microstructural and mechanical property evolution as a function of alloy composition.more » Dislocation loops with Burgers vector of a/2 111 and a 100 were detected and quantified. Results indicate precipitation of Cr-rich is primarily dependent on the bulk chromium composition. Mechanical testing of sub-size-irradiated tensile specimens indicates the hardening response seen after irradiation is dependent on the bulk chromium composition. Furthermore, a structure property relationship was developed; it indicated that the change in yield strength after irradiation is caused by the formation of these radiation-induced defects and is dominated by the large number density of Cr-rich α' precipitates at sufficiently high chromium contents after irradiation.« less

Combustion synthesis of AlB2-Al2O3 composite powders with AlB2 nanowire structures

NASA Astrophysics Data System (ADS)

Yang, Pan; Xiao, Guoqing; Ding, Donghai; Ren, Yun; Yang, Shoulei; Lv, Lihua; Hou, Xing

2018-05-01

Using of Al and B2O3 powders as starting materials, and Mg-Al alloy as additives, AlB2-Al2O3 composite powders with AlB2 nanowire structures were successfully fabricated via combustion synthesis method in Ar atmosphere at a pressure of 1.5 MPa. The effect of different amount of Mg-Al alloy on the phase compositions and morphology of the combustion products was investigated. The results revealed that AlB2 and Al2O3 increased, whereas Al decreased with the content of Mg-Al alloy increasing. The impurities MgAl2O4 and AlB12 would exist in the sample with adding of 18 wt% Mg-Al alloy. Interestingly, FESEM/TEM/EDS results showed that AlB2 nanowires were observed in the products when the content of Mg-Al alloy is 6 wt% and 12 wt%. The more AlB2 nanowires can be found as the content of Mg-Al alloy increased. And the yield of AlB2 nanowires with the diameter of about 200 nanometers (nm) and the length up to several tens of micrometers (μm) in the combustion product is highest when the content of Mg-Al alloy is 12 wt%. The vapor, such as Mg-Al (g), B2O2 (g), AlO (g) and Al2O (g), produced during the process of combustion synthesis, reacted with each other to yield AlB2 nanowires by vapor-solid (VS) mechanism and the corresponding model was also proposed.

Interfacial Phenomena in Al/Al, Al/Cu, and Cu/Cu Joints Soldered Using an Al-Zn Alloy with Ag or Cu Additions

NASA Astrophysics Data System (ADS)

Pstruś, Janusz; Gancarz, Tomasz

2014-05-01

The studies of soldered joints were carried out in systems: Al/solder/Al, Al/solder/Cu, Cu/solder/Cu, where the solder was (Al-Zn)EUT, (Al-Zn)EUT with 0.5, 1.0, and 1.5 at.% of Ag and (Al-Zn)EUT with 0.5, 1.0, and 1.5 at.% of Cu addition. Brazing was performed at 500 °C for 3 min. The EDS analysis indicated that the composition of the layers starting from the Cu pad was CuZn, Cu5Zn8, and CuZn4, respectively. Wetting tests were performed at 500 °C for 3, 8, 15, and 30 min, respectively. Thickness of the layers and their kinetics of growth were measured based on the SEM micrographs. The formation of interlayers was not observed from the side of Al pads. On the contrary, dissolution of the Al substrate and migration of Al-rich particles into the bulk of the solder were observed.

Ordered hexagonal mesoporous aluminosilicates with low Si/Al ratio: synthesis, characterization, and catalytic application.

PubMed

Liu, Aifeng; Che, Hongwei; Liu, Chuanzhi; Fu, Quanrong; Jiang, Ruijiao; Wang, Cheng; Wang, Liang

2014-06-01

Ordered hexagonal mesoporous aluminosilicates with lower Si/Al ratio below 5 have been successfully synthesized via the co-assembly of preformed aluminosilicate precursors with Gemini surfactant [C12H25N+(CH3)2(CH2)6N+(CH3)2C12H25] x 2Br(-) as the template. Powder X-ray diffraction, transmission electron microscopy, scanning electron microscopy, N2 adsorption-desorption isotherm measurements, Fourier transform infrared spectroscopy, 27Al nuclear magnetic resonance, thermogravimetric analysis, and temperature-programmed desorption of cyclohexylamine are employed to characterize the resulting samples. The phenol alkylation reaction is carried out to evaluate their catalytic performances. These studies indicate that the sample with a low Si/Al ratio of 3 still retains a highly ordered hexagonal mesoporous structure. And it also possesses the highest acidity of 0.96 mmol among the samples with lower Si/Al ratios below 5 due to its higher specific surface area together with more content of tetrahedrally coordinated Al in the framework. The catalytic tests confirm that the acidity of the samples plays a key role in determining their catalytic performances.

Orientation relationship of eutectoid FeAl and FeAl2.

PubMed

Scherf, A; Kauffmann, A; Kauffmann-Weiss, S; Scherer, T; Li, X; Stein, F; Heilmaier, M

2016-04-01

Fe-Al alloys in the aluminium range of 55-65 at.% exhibit a lamellar microstructure of B2-ordered FeAl and triclinic FeAl 2 , which is caused by a eutectoid decomposition of the high-temperature Fe 5 Al 8 phase, the so-called ∊ phase. The orientation relationship of FeAl and FeAl 2 has previously been studied by Bastin et al. [ J. Cryst. Growth (1978 ▸), 43 , 745] and Hirata et al. [ Philos. Mag. Lett. (2008 ▸), 88 , 491]. Since both results are based on different crystallographic data regarding FeAl 2 , the data are re-evaluated with respect to a recent re-determination of the FeAl 2 phase provided by Chumak et al. [ Acta Cryst. (2010 ▸), C 66 , i87]. It is found that both orientation relationships match subsequent to a rotation operation of 180° about a 〈112〉 crystallographic axis of FeAl or by applying the inversion symmetry of the FeAl 2 crystal structure as suggested by the Chumak data set. Experimental evidence for the validity of the previously determined orientation relationships was found in as-cast fully lamellar material (random texture) as well as directionally solidified material (∼〈110〉 FeAl || solidification direction) by means of orientation imaging microscopy and global texture measurements. In addition, a preferential interface between FeAl and FeAl 2 was identified by means of trace analyses using cross sectioning with a focused ion beam. On the basis of these habit planes the orientation relationship between the two phases can be described by ([Formula: see text]01) FeAl || (114)[Formula: see text] and [111] FeAl || [1[Formula: see text]0][Formula: see text]. There is no evidence for twinning within FeAl lamellae or alternating orientations of FeAl lamellae. Based on the determined orientation and interface data, an atomistic model of the structure relationship of Fe 5 Al 8 , FeAl and FeAl 2 in the vicinity of the eutectoid decomposition is derived. This model is analysed with respect to the strain which has to be

The structure of Al-23 and astrophysical consequences

NASA Astrophysics Data System (ADS)

Zhai, Yongjun

Motivated by existing nuclear astrophysics problems, the b-decay of the proton rich nucleus 23 Al was studied for the first time with pure samples which were obtained by using the 1 H( 24 Mg, 23 Al)2n reaction and the MARS recoil separator at Texas A&M University. b and b-g coincidence measurements were made with a fast tape-transport system, scintillator, BGO and HPGe g detectors. The experiment allowed us to measure absolute b branching ratios and to determine log ft values for transitions to final states in 23 Mg, including the isobaric analog state (IAS), and, therefore, to determine unambiguously the spin and parity of the 23 Al ground state to be J p = 5/2 + . This work excludes the large increases in the radiative proton capture cross section for the reaction 22 Mg(p,g) 23 Al at astrophysical energies, which were implied by claims that the spin and parity of the 23 Al ground state were J p = 1/2 + . More precise half life and mass determinations of 23 Al were obtained from the experimental data. The log ft for the Fermi transition to its isobaric analog state in 23 Mg was also determined for the first time. This IAS and a state 16 keV below it were observed, well separated in the same experiment for the first time. The b- decay scheme of the proton rich nucleus 23 Al was established. We can now solve a number of inconsistencies in the literature, exclude strong isospin mixing claimed before, and obtain a new determination of the resonance strength. The IAS and the state 16 keV below it are resonances in the 22 Na(p,g) 23 Mg reaction at energies that are important in novae. This second state turns out to be the resonance that gives the most important contribution in the depletion of 22Na from novae. Both of the reactions of 22 Mg(p,g) 23 Al and 22 Na(p,g) 23 Mg have been suggested as possible candidates for diverting some of the flux in oxygen-neon novae explosions from the A=22 into the A=23 mass chain.

Nuclear magnetic resonance properties of lunar samples.

NASA Technical Reports Server (NTRS)

Kline, D.; Weeks, R. A.

1972-01-01

Nuclear magnetic resonance spectra of Na-23, Al-27, and P-31 in fines samples 10084,60 and 14163,168 and in crystalline rock samples 12021,55 and 14321,166, have been recorded over a range of frequencies up to 20 MHz. A shift in the field at which maximum absorption occurs for all of the spectra relative to the field at which maximum absorption occurs for terrestrial analogues is attributed to a sample-dependent magnetic field at the Na, Al, and P sites opposing the laboratory field. The magnitude of these fields internal to the samples is sample dependent and varies from 5 to 10 G. These fields do not correlate with the iron content of the samples. However, the presence of single-domain particles of iron distributed throughout the plagioclase fraction that contains the principal fraction of Na and Al is inferred from electron magnetic resonance spectra shapes.

Medical and policy considerations for nuclear and radiation accidents, incidents and terrorism.

PubMed

Gale, Robert Peter

2017-11-01

The purpose of this review is to address the increasing medical and public concern regarding the health consequences of radiation exposure, a concern shaped not only by fear of another Chernobyl or Fukushima nuclear power facility accident but also by the intentional use of a nuclear weapon, a radiological dispersion device, a radiological exposure device, or an improved nuclear device by rogue states such as North Korea and terrorist organizations such as Al Qaeda and ISIS. The United States has the medical capacity to respond to a limited nuclear or radiation accident or incident but an effective medical response to a catastrophic nuclear event is impossible. Dealing effectively with nuclear and radiation accidents or incidents requires diverse strategies, including policy decisions, public education, and medical preparedness. I review medical consequences of exposures to ionizing radiations, likely concomitant injuries and potential medical intervention. These data should help haematologists and other healthcare professionals understand the principles of medical consequences of nuclear terrorism. However, the best strategy is prevention.

Inclusions and Substructures in Uranium of Nuclear Purity. Report No. 51; INCLUSIONES Y SUBESTRUCTURAS EN URANIO DE PUREZA NUCLEAR. INFORME NO. 51

DOE Office of Scientific and Technical Information (OSTI.GOV)

Biloni, H.; Lindenvald, N.; Sabato, J.A.

1961-01-01

The inclusions in uranium of nuclear purity (UC, UH/sub 3/, UO/sub 2/, UO, UN, and the complexes which include the intersolubility of U with C and N or with C, N, and O) were . analyzed metallographically, and the results reported by other authors were discussed critically. The existence of the fine precipitate reticular substructure, sensitive to thermal treatments, which generally appears in uraniunn was analyzed. Its origins were discussed in accordance with bibliographic data. Complementary data for its comprehension are given from the metallographic analysis of U--Al and U-- Fe alloys with low Al and Fe concentrations. (tr-auth)

Nature of weak magnetism in SrTiO3/LaAlO3 multilayers.

PubMed

Salman, Z; Ofer, O; Radovic, M; Hao, H; Ben Shalom, M; Chow, K H; Dagan, Y; Hossain, M D; Levy, C D P; Macfarlane, W A; Morris, G M; Patthey, L; Pearson, M R; Saadaoui, H; Schmitt, T; Wang, D; Kiefl, R F

2012-12-21

We report the observation of weak magnetism in superlattices of LaAlO(3)/SrTiO(3) using β-detected nuclear magnetic resonance. The spin lattice relaxation rate of ^{8}Li in superlattices with a spacer layers of 8 and 6 unit cells of LaAlO(3) exhibits a strong peak near ~35 K, whereas no such peak is observed in a superlattice with spacer layer thickness of 3 unit cells. We attribute the observed temperature dependence to slowing down of weakly coupled electronic moments at the LaAlO(3)/SrTiO(3) interface. These results show that the magnetism at the interface depends strongly on the thickness of the spacer layer, and that a minimal thickness of ~4-6 unit cells is required for the appearance of magnetism. A simple model is used to determine that the observed relaxation is due to small fluctuating moments (~0.002μ(B)) in the two samples with a larger LaAlO(3) spacer thickness.

Electrochemical Behavior of Al-B4C Metal Matrix Composites in NaCl Solution

PubMed Central

Han, Yu-Mei; Chen, X.-Grant

2015-01-01

Aluminum based metal matrix composites (MMCs) have received considerable attention in the automotive, aerospace and nuclear industries. One of the main challenges using Al-based MMCs is the influence of the reinforcement particles on the corrosion resistance. In the present study, the corrosion behavior of Al-B4C MMCs in a 3.5 wt.% NaCl solution were investigated using potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS) techniques. Results indicated that the corrosion resistance of the composites decreased when increasing the B4C volume fraction. Al-B4C composite was susceptible to pitting corrosion and two types of pits were observed on the composite surface. The corrosion mechanism of the composite in the NaCl solution was primarily controlled by oxygen diffusion in the solution. In addition, the galvanic couples that formed between Al matrix and B4C particles could also be responsible for the lower corrosion resistance of the composites. PMID:28793574

Status of FeCrAl ODS Irradiations in the High Flux Isotope Reactor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Field, Kevin G.; Howard, Richard H.

2016-08-19

FeCrAl oxide-dispersion strengthened (ODS) alloys are an attractive sub-set alloy class of the more global FeCrAl material class for nuclear applications due to their high-temperature steam oxidation resistance and hypothesized enhanced radiation tolerance. A need currently exists to determine the radiation tolerance of these newly developed alloys. To address this need, a preliminary study was conducted using the High Flux Isotope Reactor (HFIR) to irradiate an early generation FeCrAl ODS alloy, 125YF. Preliminary post-irradiation examination (PIE) on these irradiated specimens have shown good radiation tolerance at elevated temperatures (≥330°C) but possible radiation-induced hardening and embrittlement at irradiations of 200°C tomore » a damage level of 1.9 displacement per atom (dpa). Building on this experience, a new series of irradiations are currently being conceptualized. This irradiation series called the FCAD irradiation program will irradiate the latest generation FeCrAl ODS and FeCr ODS alloys to significantly higher doses. These experiments will provide the necessary information to determine the mechanical performance of irradiated FeCrAl ODS alloys at light water reactor and fast reactor conditions.« less

Effects of Containment on Radionuclide Releases from Underground Nuclear Explosions

NASA Astrophysics Data System (ADS)

Carrigan, C. R.; Sun, Y.

2016-12-01

Confirming the occurrence of an underground nuclear explosion can require capturing short-lived noble gas radioisotopes produced by the explosion, sometimes referred to as the "smoking gun" for nuclear explosion detection. It is well known that the radioisotopic distribution resulting from the detonation evolves with time in the explosion cavity. In effect, the explosion cavity or chimney behaves as a chemical reactor. As long as the parent and daughter radionuclides remain in a closed and well-mixed cavity, parameters, such as radioxenon isotopic ratios, can be calculated analytically from a decay-chain network model. When gases from the cavity migrate into the containment regime, consideration of a "leaky reactor" model is more appropriate. We consider several implications of such a leaky reactor model relevant to interpretations of gas samples from the subsurface during an on-site inspection that could potentially be carried out under the Comprehensive Nuclear Test Ban Treaty. Additionally, we have attempted to validate our leaky reactor model against atmospheric observations of radioactive xenon isotopes detected by radionuclide monitoring stations in Japan and Russia following the February 2013 DPRK underground nuclear explosion (Carrigan et al., 2016). While both model uncertainty and observational error are significant, our model of isotopic evolution appears to be in broad agreement with radionuclide observations, and for the first time links atmospheric measurements of radioxenon isotopic ratios to estimates of seismic yield. Carrigan et al., Scientific Reports 6, Article number: 23032 (2016) doi:10.1038/srep23032

Ohmic contacts to Al-rich AlGaN heterostructures

DOE PAGES

Douglas, E. A.; Reza, S.; Sanchez, C.; ...

2017-06-06

Due to the ultra-wide bandgap of Al-rich AlGaN, up to 5.8 eV for the structures in this study, obtaining low resistance ohmic contacts is inherently difficult to achieve. A comparative study of three different fabrication schemes is presented for obtaining ohmic contacts to an Al-rich AlGaN channel. Schottky-like behavior was observed for several different planar metallization stacks (and anneal temperatures), in addition to a dry-etch recess metallization contact scheme on Al 0.85Ga 0.15N/Al 0.66Ga 0.34N. However, a dry etch recess followed by n +-GaN regrowth fabrication process is reported as a means to obtain lower contact resistivity ohmic contacts onmore » a Al 0.85Ga 0.15N/Al 0.66Ga 0.34N heterostructure. In conclusion, specific contact resistivity of 5×10 -3 Ω cm 2 was achieved after annealing Ti/Al/Ni/Au metallization.« less

Growth and stress-induced transformation of zinc blende AlN layers in Al-AlN-TiN multilayers

DOE PAGES

Li, Nan; Yadav, Satyesh K.; Wang, Jian; ...

2015-12-18

We report that AlN nanolayers in sputter deposited {111}Al/AlN/TiN multilayers exhibit the metastable zinc-blende-structure (z-AlN). Based on density function theory calculations, the growth of the z-AlN is ascribed to the kinetically and energetically favored nitridation of the deposited aluminium layer. In situ nanoindentation of the as-deposited {111}Al/AlN/TiN multilayers in a high-resolution transmission electron microscope revealed the z-AlN to wurzite AlN phase transformation through collective glide of Shockley partial dislocations on every two {111} planes of the z-AlN.

Electrical switching in Sb doped Al23Te77 glasses

NASA Astrophysics Data System (ADS)

Pumlianmunga; Ramesh, K.

2017-08-01

Bulk glasses (Al23Te77)Sbx (0≤ x≤10) prepared by melt quenching method show a change in switching type from threshold to memory for x≥5. An increase in threshold current (Ith) and a concomitant decrease in threshold voltage (Vth) and resisitivity(ρ) have been observed with the increase of Sb content. Raman spectra of the switched region in memory switching compositions show a red shift with respect to the as prepared glasses whereas in threshold switching compositions no such shift is observed. The magic angle spinning nuclear magnetic resonance (MAS NMR) of 27Al atom shows three different environments for Al ([4]Al, [5]Al and [6]Al). The samples annealed at their respective crystallization temperatures show rapid increase in [4]Al sites by annihilating [5]Al sites. The melts of threshold switching glasses (x≤2.5) quenched in water at room temperature (27 °C) show amorphous structure whereas, the melt of memory switching glasses (x>2.5) solidify into crystalline structure. The higher coordination of Al increases the cross-linking and rigidity. The addition of Sb increases the glass transition(Tg) and decreases the crystallization temperature(Tc). The decrease in the interval between the Tg and Tc eases the transition between the amorphous and crystalline states and improves the memory properties. The temperature rise at the time of switching can be as high as its melting temperature and the material in between the electrodes may melt to form a filament. The filament may consists of temporary (high resistive amorphous) and permanent (high conducting crystalline) units. The ratio between the temporary and the permanent units may decide the switching type. The filament is dominated by the permanent units in memory switching compositions and by the temporary units in threshold switching compositions. The present study suggests that both the threshold and memory switching can be understood by the thermal model and filament formation.

Can shale safely host US nuclear waste?

USGS Publications Warehouse

Neuzil, C.E.

2013-01-01

"Even as cleanup efforts after Japan’s Fukushima disaster offer a stark reminder of the spent nuclear fuel (SNF) stored at nuclear plants worldwide, the decision in 2009 to scrap Yucca Mountain as a permanent disposal site has dimmed hope for a repository for SNF and other high-level nuclear waste (HLW) in the United States anytime soon. About 70,000 metric tons of SNF are now in pool or dry cask storage at 75 sites across the United States [Government Accountability Office, 2012], and uncertainty about its fate is hobbling future development of nuclear power, increasing costs for utilities, and creating a liability for American taxpayers [Blue Ribbon Commission on America’s Nuclear Future, 2012].However, abandoning Yucca Mountain could also result in broadening geologic options for hosting America’s nuclear waste. Shales and other argillaceous formations (mudrocks, clays, and similar clay-rich media) have been absent from the U.S. repository program. In contrast, France, Switzerland, and Belgium are now planning repositories in argillaceous formations after extensive research in underground laboratories on the safety and feasibility of such an approach [Blue Ribbon Commission on America’s Nuclear Future, 2012; Nationale Genossenschaft für die Lagerung radioaktiver Abfälle (NAGRA), 2010; Organisme national des déchets radioactifs et des matières fissiles enrichies, 2011]. Other nations, notably Japan, Canada, and the United Kingdom, are studying argillaceous formations or may consider them in their siting programs [Japan Atomic Energy Agency, 2012; Nuclear Waste Management Organization (NWMO), (2011a); Powell et al., 2010]."

The Trilateral Force: The Atlantic Alliance and the Future of Nuclear Weapons Strategy

DTIC Science & Technology

2013-12-03

Western World, Atlantic Council (2013), 46. s Paul Bracken, The Second Nuclear Age: Strategy, Danger, and the New Power Politics (New York: Times...Studies Institute (2013); Paul Bracken, "The Bomb Returns for a Second Act," Foreign Policy Research Institute E- Notes, November (2012). 11 David...Commission Report: Modernizing US. Nuclear Strategy, Force Structure and Posture, Global Zero (2012), 6. 27 Dana Johnson, et al., "Triad, Dyad, Monad

Climate and smoke - An appraisal of nuclear winter

NASA Technical Reports Server (NTRS)

Turco, R. P.; Toon, O. B.; Pollack, J. B.; Ackerman, T. P.; Sagan, C.

1990-01-01

A reevaluation is presented of the 'nuclear winter' scenario of Turco et al. (1983). New pertinent data have emerged from laboratory studies, field experiments, and numerical models on the smoke-plume, mesoscale, and global scales. A full-scale nuclear exchange's probable soot injections lead, in three-dimensional climate simulations, to midsummer land temperature decreases averaging 10-20 C in northern midlatitudes, with local cooling of as much as 35 C. Anomalous circulation patterns due to solar heating of the soot could stabilize the upper atmosphere against overturning, thereby prolonging the soot's residence time in the atmosphere. Monsoon disruptions and severe ozone layer depletion are also foreseen.

Abnormal assembly of annulate lamellae and nuclear pore complexes coincides with fertilization arrest at the pronuclear stage of human zygotic development.

PubMed

Rawe, V Y; Olmedo, S Brugo; Nodar, F N; Ponzio, R; Sutovsky, P

2003-03-01

The assembly of nuclear pore complexes (NPC) and their cytoplasmic stacks, annulate lamellae (AL), promote normal nucleocytoplasmic trafficking and accompany pronuclear development within the mammalian zygote. Previous studies showed that a percentage of human oocytes fertilized in vitro failed to develop normal pronuclei and cleave within 40-48 h post insemination. We hypothesized that an aberrant recruitment of NPC proteins, nucleoporins and/or NPC preassembled into AL, might accompany human fertilization arrest. We explored NPC and AL assembly in unfertilized human oocytes, and fertilized and arrested zygotes by immunofluorescence with an NPC- and AL-specific antibody, mAb 414, and by transmission electron microscopy. Major NPC or AL assembly was not observed in the unfertilized human oocytes. Once fertilization took place, the formation of AL was observed throughout the cytoplasm and near the developing pronuclei with NPC. On the contrary, NPC assembly was disrupted in the arrested zygotes, whereas AL were clustered into large sheaths. This was accompanied by the lack of NPC incorporation into the nuclear envelopes. We conclude that the aberrant assembly of NPC and AL coincides with early developmental failure in humans.

Comparing the Thermodynamic Behaviour of Al(1)+ZrO2(s) to Al(1)+Al2O3(s)

NASA Technical Reports Server (NTRS)

Copland, Evan

2004-01-01

In an effort to better determine the thermodynamic properties of Al(g) and Al2O(g). the vapor in equilibrium with Al(l)+ZrO2(s) was compared to the vapor in equilibrium with Al(l)+Al2O3(s) over temperature range 1197-to-1509K. The comparison was made directly by Knudsen effusion-cell mass spectrometry with an instrument configured for a multiple effusion-cell vapor source (multi-cell KEMS). Second law enthalpies of vaporization of Al(g) and Al2O(g) together with activity measurements show that Al(l)+ZrO2(s) is thermodynamically equivalent to Al(l)+Al2O3(s), indicating Al(l) remained pure and Al2O3(s) was present in the ZrO2-cell. Subsequent observation of the Al(l)/ZrO2 and vapor/ZrO2 interfaces revealed a thin Al2O3-layer had formed, separating the ZrO2-cell from Al(l) and Al(g)+Al2O(g), effectively transforming it into an Al2O3 effusion-cell. This behavior agrees with recent observations made for Beta-NiAl(Pt) alloys measured in ZrO2 effusion-cell.

Anisotropy of Spin Fluctuations in a Tetragonal Heavy Fermion Antiferromagnet CeRhAl 4 Si 2

DOE PAGES

Sakai, H.; Hattori, T.; Tokunaga, Y.; ...

2017-06-01

An antiferromagnetic (AFM) Kondo lattice compound CeRhAl 4Si 2, which exhibits successive AFM transitions at T N1=14 K and T N2=9 K in zero external field, has been microscopically investigated by means of 27Al nuclear magnetic resonance (NMR) technique. In the high temperature range, magnetic excitations of 4f electrons can be well explained by isotropic localized spin fluctuations. Below ~50 K, it begins to show a characteristic anisotropy of spin fluctuations, which suggests a competition between spin fluctuations and nesting instability in this system.

Nanoporous Al sandwich foils using size effect of Al layer thickness during Cu/Al/Cu laminate rolling

NASA Astrophysics Data System (ADS)

Yu, Hailiang; Lu, Cheng; Tieu, A. Kiet; Li, Huijun; Godbole, Ajit; Kong, Charlie

2018-06-01

The roll bonding technique is one of the most widely used methods to produce metal laminate sheets. Such sheets offer interesting research opportunities for both scientists and engineers. In this paper, we report on an experimental investigation of the 'thickness effect' during laminate rolling for the first time. Using a four-high multifunction rolling mill, Cu/Al/Cu laminate sheets were fabricated with a range of thicknesses (16, 40, 70 and 130 μm) of the Al layer. The thickness of the Cu sheets was a constant 300 μm. After rolling, TEM images show good bonding quality between the Cu and Al layers. However, there are many nanoscale pores in the Al layer. The fraction of nanoscale pores in the Al layer increases with a reduction in the Al layer thickness. The finite element method was used to simulate the Cu/Al/Cu rolling process. The simulation results reveal the effect of the Al layer thickness on the deformation characteristics of the Cu/Al/Cu laminate. Finally, we propose that the size effect of the Al layer thickness during Cu/Al/Cu laminate rolling may offer a method to fabricate 'nanoporous' Al sandwich laminate foils. Such foils can be used in electromagnetic shielding of electrical devices and noisy shielding of building.

Molecular shuttle chelation: the use of ascorbate, desferrioxamine and Feralex-G in combination to remove nuclear bound aluminum.

PubMed

Kruck, Theo P; Cui, Jian-Guo; Percy, Maire E; Lukiw, Walter J

2004-06-01

1. Abundant data suggest that aluminum (Al(III)) exposure may be an environmental risk factor contributing to the development, progression and/or neuropathology of several human neurodegenerative disorders, including Alzheimer's disease (AD). 2. Nuclei appear to be one directed target for Al(III) binding, accumulation, and Al(III)-mediated dysfunction due in part to their high content of polyphosphorylated nucleic acids, nucleotides, and nucleoproteins. 3. The design of chelation therapies dealing with the removal of Al(III) from these genetic compartments therefore represents an attractive strategy to alleviate the development and/or progression of central nervous system dysfunction that may arise from excessive Al(III) exposure. 4. In this study we have investigated the potential application of 10 natural and synthetic Al(III) chelators, including ascorbate (AS), desferrioxamine (DF), and Feralex-G (FG), used either alone or in combination, to remove Al(III) preincubated with intact human brain cell nuclei. 5. Although nuclear bound Al(III) was found to be highly refractory to removal, the combination of AS+FG was found to be particularly effective in removing Al(III) from the nuclear matrix. 6. Our data suggest that chelators carrying cis-hydroxy ketone groups, such as FG, are particularly suited to the removal of Al(III) from complex biological systems. 7. We further suggest a mechanism whereby small chelating molecules may penetrate the nucleus, bind Al(III), diffuse to regions accessible by the larger DF or FG molecules and transfer their Al(III) to DF or FG. 8. The proposed mechanism, called molecular shuttle chelation may provide a useful pharmacotherapy in the potential treatment of Al(III) overload disease.

Comment on "Nuclear genomic sequences reveal that polar bears are an old and distinct bear lineage".

PubMed

Nakagome, Shigeki; Mano, Shuhei; Hasegawa, Masami

2013-03-29

Based on nuclear and mitochondrial DNA, Hailer et al. (Reports, 20 April 2012, p. 344) suggested early divergence of polar bears from a common ancestor with brown bears and subsequent introgression. Our population genetic analysis that traces each of the genealogies in the independent nuclear loci does not support the evolutionary model proposed by the authors.

WOx supported on γ-Al2O3 with different morphologies as model catalysts for alkanol dehydration

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shi, Dachuan; Wang, Huamin; Kovarik, Libor

2018-04-21

The distinctive morphological and surface characteristics of platelet-like γ-Al2O3 were compared to a regular, commercial γ-Al2O3. γ-Al2O3 platelets display dominant (110) surface facets and higher densities of coordinative unsaturated penta-coordinate Al3+ (Al3+penta) sites than regular γ-Al2O3, as measured by solid-state magic-angle spinning nuclear magnetic resonance spectroscopy (MAS NMR). Such Al3+penta sites are also the preferred surface anchoring sites for tungsten oxide (WOx) species consistent with NMR analysis indicating that these sites are consumed upon WOx adsorption. The higher Al3+penta density on γ-Al2O3 platelets leads to greater WOx dispersion (or smaller WOx clusters), as demonstrated by scanning transmission electron microscopy andmore » ultraviolet–visible spectroscopy, and WOx species at intermediate WOx surface concentration are the most active for the probe reaction of 2-butanol dehydration. WOx on γ-Al2O3 platelets approaches the highest turnover rates at higher surface densities than WOx on regular γ-Al2O3, yet with similar highest rate values for both series of catalysts. This indicates that different Al2O3 supports mainly affect the dispersion of supported WOx rather than the intrinsic reactivity of individual WOx clusters with similar size.« less

"Other" indirect methods for nuclear astrophysics

NASA Astrophysics Data System (ADS)

Trache, Livius

2018-01-01

In the house of Trojan Horse Method (THM), I will say a few words about "other" indirect methods we use in Nuclear Physics for Astrophysics. In particular those using Rare Ion Beams that can be used to evaluate radiative proton capture reactions. I add words about work done with the Professore we celebrate today. With a proposal, and some results with TECSA, for a simple method to produce and use isomeric beam of 26mAl.

Ti{sub 2}AlN thin films synthesized by annealing of (Ti+Al)/AlN multilayers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cabioch, Thierry, E-mail: Thierry.cabioch@univ-poitiers.fr; Alkazaz, Malaz; Beaufort, Marie-France

2016-08-15

Highlights: • Epitaxial thin films of the MAX phase Ti{sub 2}AlN are obtained by thermal annealing. • A new metastable (Ti,Al,N) solid solution with the structure of α-T is evidenced. • The formation of the MAX phase occurs at low temperature (600 °C). - Abstract: Single-phase Ti{sub 2}AlN thin films were obtained by annealing in vacuum of (Ti + Al)/AlN multilayers deposited at room temperature by magnetron sputtering onto single-crystalline (0001) 4H-SiC and (0001) Al{sub 2}O{sub 3} substrates. In-situ X-ray diffraction experiments combined with ex-situ cross-sectional transmission electron microscopy observations reveal that interdiffusion processes occur in the multilayer at amore » temperature of ∼400 °C leading to the formation of a (Ti, Al, N) solid solution, having the hexagonal structure of α-Ti, whereas the formation of Ti{sub 2}AlN occurs at 550–600 °C. Highly oriented (0002) Ti{sub 2}AlN thin films can be obtained after an annealing at 750 °C.« less

Constraints on CEMP-no progenitors from nuclear astrophysics

NASA Astrophysics Data System (ADS)

Choplin, Arthur; Maeder, André; Meynet, Georges; Chiappini, Cristina

2016-09-01

Context. The CEMP-no stars are long-lived small mass stars presenting a very low iron content and overabundances of carbon with no sign or only very weak signs of s- or r-elements. Although the origin of this abundance pattern is still a matter of debate, it was very likely inherited from a previous massive star, which we call the source star. Aims: We rely on a recent classification of CEMP-no stars arguing that some of them are made of a material processed by hydrogen burning that was enriched in products of helium burning during the nuclear life of the source star. We examine the possibility of forming CEMP-no stars with this material. Methods: We study the nucleosynthesis of the CNO cycle and the Ne-Na Mg-Al chains in a hydrogen burning single zone while injecting the helium burning products 12C, 16O, 22Ne, and 26Mg. We investigate the impact of changing density, temperature and the injection rate. The nuclear reaction rates involving the creation and destruction of 27Al are also examined. Results: 14N, 23Na, 24Mg, and 27Al are formed when injecting 12C, 16O, 22Ne, and 26Mg in the hydrogen burning zone. The 12C/13C ratio is constant under various conditions in the hydrogen burning zone. The predicted [Al/Fe] ratio varies up to ~ 2 dex depending on the prescription used for the reaction rates involving 27Al. Conclusions: The experiments we carried out support the view that some CEMP-no stars are made of a material processed by hydrogen burning that comes from a massive star experiencing mild to strong rotational mixing. During its burning, this material was likely enriched in helium burning products. No material coming from the carbon-oxygen rich core of the source star should be added to form the daughter star, otherwise the 12C/13C ratio would be largely above the observed range of values.

The Effect of Electronic Paramagnetism on Nuclear Magnetic Resonance Frequencies in Metals

DOE R&D Accomplishments Database

Townes, C. H.; Herring, C.; Knight, W. D.

1950-09-22

Observations on the shifts of nuclear resonances in metals ( Li{sup 7}, Na{sup 23}, Cu {sup 63}, Be{sup 9}, Pb{sup 207}, Al{sup 27}, and Ca{sup 69} ) due to free electron paramagnetism; comparison with theoretical values.

Spectroscopy of Al wire array stagnation on Z

NASA Astrophysics Data System (ADS)

Jones, B.; Jennings, C. A.; Hansen, S. B.; Bailey, J. E.; Rochau, G. A.; Coverdale, C. A.; Yu, E. P.; Ampleford, D. J.; Cuneo, M. E.; Maron, Y.; Fisher, V. I.; Bernshtam, V.; Starobinets, A.; Weingarten, L.; Pinhas, S.

2011-10-01

In this work, we present analysis of time-gated spectra of ~2 keV K-shell emissions from Al (5% Mg) wire arrays on Z to provide details of the plasma conditions and dynamics at the onset of stagnation. The plasma is modeled as concentric radial zones, and collisional-radiative modeling with self-consistent radiation transport is used to constrain the temperatures and densities in these regions. A hot ~2 keV plasma core bearing a few percent of the total mass forms at the foot of the x-ray pulse, with participating mass increasing toward peak x-ray power as material arrives on axis with ~50 cm/ μs implosion velocity. The atomic modeling accounts for K-shell line opacity and Doppler effects, and is compared to 3D MHD simulations. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. DOE National Nuclear Security Administration under contract DE-AC04-94AL85000.

Frequent somatic transfer of mitochondrial DNA into the nuclear genome of human cancer cells.

PubMed

Ju, Young Seok; Tubio, Jose M C; Mifsud, William; Fu, Beiyuan; Davies, Helen R; Ramakrishna, Manasa; Li, Yilong; Yates, Lucy; Gundem, Gunes; Tarpey, Patrick S; Behjati, Sam; Papaemmanuil, Elli; Martin, Sancha; Fullam, Anthony; Gerstung, Moritz; Nangalia, Jyoti; Green, Anthony R; Caldas, Carlos; Borg, Åke; Tutt, Andrew; Lee, Ming Ta Michael; van't Veer, Laura J; Tan, Benita K T; Aparicio, Samuel; Span, Paul N; Martens, John W M; Knappskog, Stian; Vincent-Salomon, Anne; Børresen-Dale, Anne-Lise; Eyfjörd, Jórunn Erla; Myklebost, Ola; Flanagan, Adrienne M; Foster, Christopher; Neal, David E; Cooper, Colin; Eeles, Rosalind; Bova, Steven G; Lakhani, Sunil R; Desmedt, Christine; Thomas, Gilles; Richardson, Andrea L; Purdie, Colin A; Thompson, Alastair M; McDermott, Ultan; Yang, Fengtang; Nik-Zainal, Serena; Campbell, Peter J; Stratton, Michael R

2015-06-01

Mitochondrial genomes are separated from the nuclear genome for most of the cell cycle by the nuclear double membrane, intervening cytoplasm, and the mitochondrial double membrane. Despite these physical barriers, we show that somatically acquired mitochondrial-nuclear genome fusion sequences are present in cancer cells. Most occur in conjunction with intranuclear genomic rearrangements, and the features of the fusion fragments indicate that nonhomologous end joining and/or replication-dependent DNA double-strand break repair are the dominant mechanisms involved. Remarkably, mitochondrial-nuclear genome fusions occur at a similar rate per base pair of DNA as interchromosomal nuclear rearrangements, indicating the presence of a high frequency of contact between mitochondrial and nuclear DNA in some somatic cells. Transmission of mitochondrial DNA to the nuclear genome occurs in neoplastically transformed cells, but we do not exclude the possibility that some mitochondrial-nuclear DNA fusions observed in cancer occurred years earlier in normal somatic cells. © 2015 Ju et al.; Published by Cold Spring Harbor Laboratory Press.

Ion Association in AlCl3 Aqueous Solutions from Constrained First-Principles Molecular Dynamics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cauet, Emilie L.; Bogatko, Stuart A.; Bylaska, Eric J.

2012-10-15

Ab initio molecular dynamics was used to investigate the ion pairing behavior between Cl- and the Al3+ ion in an aqueous AlCl3 solution containing 63 water molecules. A series of constrained simulations was carried out at 300 K for up to 16 ps each, by fixing the inter-nuclear separation (rAl-Cl) between the Al3+ ion and one of the Cl- ions. The calculated potential of mean force of the Al3+-Cl- ion pair shows a pronounced minimum at rAl-Cl = 2.3 Å corresponding to a contact ion pair (CIP). Two local minima assigned to solvent separated ion pairs (SSIP) are identified atmore » rAl-Cl= 4.4 and 6.0 Å. The positions of the free energy minima coincide with the hydration shell intervals of the Al3+ cation suggesting that the Cl- ion is inclined to reside in regions of low concentration of waters, i.e. between the 1st and 2nd shells of Al3+ and between the 2nd shell and bulk. A detailed analysis of solvent structure around the Al3+ and Cl- ions as a function of rAl-Cl is presented. The results are compared to structure data from X-ray measurements and unconstrained AIMD simulations of single ions Al3+ and Cl- and AlCl3 solutions. The dipole moment of the water molecules inside the 1st and 2nd hydration shells of Al3+ and in the bulk region and those of the Clion were calculated as a function of rAl-Cl. Major changes in the electronic structure of the system result from the removal of Cl- from the 1st hydration shell of the Al3+ cation. Finally, two unconstrained AIMD simulations of aqueous AlCl3 solutions corresponding to CIP and SSIP configurations were performed (17 ps, 300 K). Only minor structural changes are observed in these systems, confirming their stability.« less

ALS Association

MedlinePlus

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Potential Fuel Loadings, Fire Ignitions, and Smoke Emissions from Nuclear Bursts in Megacities

NASA Astrophysics Data System (ADS)

Turco, R. P.; Toon, O. B.; Robock, A.; Bardeen, C.; Oman, L.; Stenchikov, G. L.

2006-12-01

We consider the effects of "small" nuclear detonations in modern "megacities," focusing on the possible extent of fire ignitions, and the properties of corresponding smoke emissions. Explosive devices in the multi-kiloton yield range are being produced by a growing number of nuclear states (Toon et al., 2006), and such weapons may eventually fall into the hands of terrorists. The numbers of nuclear weapons that might be used in a regional conflict, and their potential impacts on population and infrastructure, are discussed elsewhere. Here, we estimate the smoke emissions that could lead to widespread environmental effects, including large-scale climate anomalies. We find that low-yield weapons, which emerging nuclear states have been stockpiling, and which are likely to be targeted against cities in a regional war, can generate up to 100 times as much smoke per kiloton of yield as the high-yield weapons once associated with a superpower nuclear exchange. The fuel loadings in modern cities are estimated using a variety of data, including extrapolations from earlier detailed studies. The probability of ignition and combustion of fuels, smoke emission factors and radiative properties, and prompt scavenging and dispersion of the smoke are summarized. We conclude that a small regional nuclear war might generate up to 5 teragrams of highly absorbing particles in urban firestorms, and that this smoke could initially be injected into the middle and upper troposphere. These results are used to develop smoke emission scenarios for a climate impact analysis reported by Oman et al. (2006). Uncertainties in the present smoke estimates are outlined. Oman, L., A. Robock, G. L. Stenchikov, O. B. Toon, C. Bardeen and R. P. Turco, "Climatic consequences of regional nuclear conflicts," AGU, Fall 2006. Toon, O. B., R. P. Turco, A. Robock, C. Bardeen, L. Oman and G. L. Stenchikov, "Consequences of regional scale nuclear conflicts and acts of individual nuclear terrorism," AGU, Fall

[Cardiac transplantation and neoplasms: experiences at Escola Paulista de Medicina of the Federal University of São Paulo].

PubMed

Mello Junior, Walter Teixeira de; Branco, João Nelson R; Catani, Roberto; Aguiar, Luciano de Figueiredo; Paez, Rodrigo Pereira; Buffolo, Enio

2006-02-01

To study the occurrence and types of neoplasms developed by patients who underwent an orthotopic cardiac transplantation under the Program of Cardiac Transplantation of Escola Paulista de Medicina, Federal University of São Paulo. This is an observational study of 106 patients who underwent orthotopic cardiac transplantation from November 1986 to September 2002 and survived at least thirty days following the procedure. The triple immunosuppressive regimen given included cyclosporin A, azathioprine and a corticosteroid agent. Only two patients received OKT3 in addition to the regimen established. Mean follow-up was 61.4 months (ranging from two months to 192 months). Twenty-three patients (21.3%) developed neoplasms--56.5% of these were skin neoplasm, 30.1%, solid tumors, and 13.4% of post-transplant lymphoproliferative disease (PTLD). Mean interval between transplantation and diagnosis of neoplasm was: 54.9 months for skin neoplasm; 24.8 months for solid tumors and 70.3 months for PTLD. Malignant neoplasms are relatively common in the population studied. Skin cancer was the most common type compared to the other types of neoplasms. Solid tumors were more frequently diagnosed than the lymphoproliferative diseases in the population examined.

Nuclear export receptor CRM1 recognizes diverse conformations in nuclear export signals.

PubMed

Fung, Ho Yee Joyce; Fu, Szu-Chin; Chook, Yuh Min

2017-03-10

Nuclear export receptor CRM1 binds highly variable nuclear export signals (NESs) in hundreds of different cargoes. Previously we have shown that CRM1 binds NESs in both polypeptide orientations (Fung et al., 2015). Here, we show crystal structures of CRM1 bound to eight additional NESs which reveal diverse conformations that range from loop-like to all-helix, which occupy different extents of the invariant NES-binding groove. Analysis of all NES structures show 5-6 distinct backbone conformations where the only conserved secondary structural element is one turn of helix that binds the central portion of the CRM1 groove. All NESs also participate in main chain hydrogen bonding with human CRM1 Lys568 side chain, which acts as a specificity filter that prevents binding of non-NES peptides. The large conformational range of NES backbones explains the lack of a fixed pattern for its 3-5 hydrophobic anchor residues, which in turn explains the large array of peptide sequences that can function as NESs.

Glossary on the environmental impact of a nuclear war. Technical note

DOE Office of Scientific and Technical Information (OSTI.GOV)

Verstraete, M.M.

1986-02-01

The glossary defines a number of words, expressions, and acronyms used in the description of the impact of nuclear war on the environment, and associated issues. Selected additional words related to the problems of armaments, disarmament, and nuclear war in general were also added for convenience, although terms and expressions specifically related to the medical aspects of the problem were not included. The glossary is an enlarged and updated version of the glossary that was published as part of the SCOPE-Enuwar study on the same subject, and published by Wiley (Pittock et al., 1986).

Critical Nuclear Charge of the Quantum Mechanical Three-Body Problem

NASA Astrophysics Data System (ADS)

Busuttil, Michael; Moini, Amirreza; Drake, Gordon W. F.

2014-05-01

The critical nuclear charge (Zc) for a three-body quantum mechanical system consisting of positive and negative charges is the minimum nuclear charge that can keep the system in a bound state. Here we present a study of the critical nuclear charge for two-electron (heliumlike) systems with infinite nuclear mass, and also a range of reduced mass ratio (μ / m) up to 0.5. The results help to resolve a discrepancy in the literature for the infinite mass case, and they are the first to study the dependence on reduced mass ratio. It was found that Zc has a local maximum with μ / m = 0 . 352 5 . The critical charge for the infinite mass case is found to be Zc = 0 . 911 028 224 076 8 (1 0) . This value is more accurate than any previous value in the literature, and agrees with the upper bound Zc = 0 . 911 03 reported by Baker et al.. The critical nuclear charge outside this range [0.5 - 1.0] still needs to be investigated in future works. Research Supported by NSERC and SHARCNET.

Semiclassical Calculations of Peripheral Heavy-Ion Collisions at Fermi Energies and the Nuclear Equation of State

NASA Astrophysics Data System (ADS)

Souliotis, G. A.; Shetty, D. V.; Galanopoulos, S.; Yennello, S. J.

2008-10-01

A systematic study of quasi-elastic and deep-inelastic collisions at Fermi energies has been undertaken at Texas A&M aiming at obtaining information on the mechanism of nucleon exchange and the course towards N/Z equilibration [1,2]. We expect to get insight in the dynamics and the nuclear equation of state by comparing our experimental heavy residue data to detailed calculations using microscopic models of quantum molecular dynamics (QMD) type. At present, we have performed detailed calculations using the code CoMD (Constrained Molecular Dynamics) of A. Bonasera and M. Papa [3]. The code implements an effective interaction with a nuclear-matter compressibility of K=200 (soft EOS) with several forms of the density dependence of the nucleon-nucleon symmetry potential. CoMD imposes a constraint in the phase space occupation for each nucleon, effectively restoring the Pauli principle at each time step of the collision. Results of the calculations and comparisons with our data will be presented and implications concerning the isospin part of the nuclear equation of state will be discussed. [1] G.A. Souliotis et al., Phys. Rev. Lett. 91, 022701 (2003). [2] G.A. Souliotis et al., Phys. Lett. B 588, 35 (2004). [3] M. Papa et al., Phys. Rev. C 64, 024612 (2001).

Doses from external irradiation to Marshall Islanders from Bikini and Enewetak nuclear weapons tests.

PubMed

Bouville, André; Beck, Harold L; Simon, Steven L

2010-08-01

Annual doses from external irradiation resulting from exposure to fallout from the 65 atmospheric nuclear weapons tests conducted in the Marshall Islands at Bikini and Enewetak between 1946 and 1958 have been estimated for the first time for Marshallese living on all inhabited atolls. All tests that deposited fallout on any of the 23 inhabited atolls or separate reef islands have been considered. The methodology used to estimate the radiation doses at the inhabited atolls is based on test- and location-specific radiation survey data, deposition density estimates of 137Cs, and fallout times-of-arrival provided in a companion paper (Beck et al.), combined with information on the radionuclide composition of the fallout at various times after each test. These estimates of doses from external irradiation have been combined with corresponding estimates of doses from internal irradiation, given in a companion paper (Simon et al.), to assess the cancer risks among the Marshallese population (Land et al.) resulting from exposure to radiation from the nuclear weapons tests.

Medicina array demonstrator: calibration and radiation pattern characterization using a UAV-mounted radio-frequency source

NASA Astrophysics Data System (ADS)

Pupillo, G.; Naldi, G.; Bianchi, G.; Mattana, A.; Monari, J.; Perini, F.; Poloni, M.; Schiaffino, M.; Bolli, P.; Lingua, A.; Aicardi, I.; Bendea, H.; Maschio, P.; Piras, M.; Virone, G.; Paonessa, F.; Farooqui, Z.; Tibaldi, A.; Addamo, G.; Peverini, O. A.; Tascone, R.; Wijnholds, S. J.

2015-06-01

One of the most challenging aspects of the new-generation Low-Frequency Aperture Array (LFAA) radio telescopes is instrument calibration. The operational LOw-Frequency ARray (LOFAR) instrument and the future LFAA element of the Square Kilometre Array (SKA) require advanced calibration techniques to reach the expected outstanding performance. In this framework, a small array, called Medicina Array Demonstrator (MAD), has been designed and installed in Italy to provide a test bench for antenna characterization and calibration techniques based on a flying artificial test source. A radio-frequency tone is transmitted through a dipole antenna mounted on a micro Unmanned Aerial Vehicle (UAV) (hexacopter) and received by each element of the array. A modern digital FPGA-based back-end is responsible for both data-acquisition and data-reduction. A simple amplitude and phase equalization algorithm is exploited for array calibration owing to the high stability and accuracy of the developed artificial test source. Both the measured embedded element patterns and calibrated array patterns are found to be in good agreement with the simulated data. The successful measurement campaign has demonstrated that a UAV-mounted test source provides a means to accurately validate and calibrate the full-polarized response of an antenna/array in operating conditions, including consequently effects like mutual coupling between the array elements and contribution of the environment to the antenna patterns. A similar system can therefore find a future application in the SKA-LFAA context.

Hafnium influence on the microstructure of FeCrAl alloys

NASA Astrophysics Data System (ADS)

Geanta, V.; Voiculescu, I.; Stanciu, E.-M.

2016-06-01

Due to their special properties at high temperatures, FeCrAl alloys micro-alloyed with Zr can be regarded as potential materials for use at nuclear power plants, generation 4R. These materials are resistant to oxidation at high temperatures, to corrosion, erosion and to the penetrating radiations in liquid metal environments. Also, these are able to form continuously, by the self-generation process of an oxide coating with high adhesive strength. The protective oxide layers must be textured and regenerable, with a good mechanical strength, so that crack and peeling can not appear. To improve the mechanical and chemical characteristics of the oxide layer, we introduced limited quantities of Zr, Ti, Y, Hf, Ce in the range of 1-3%wt in the FeCrAl alloy. These elements, with very high affinity to the oxygen, are capable to stabilize the alumina structure and to improve the oxide adherence to the metallic substrate. FeCrAl alloys microalloyed with Hf were prepared using VAR (Vacuum Arc Remelting) unit, under high argon purity atmosphere. Three different experimental alloys have been prepared using the same metallic matrix of Fe-14Cr-5Al, by adding of 0.5%wt Hf, 1.0%wt Hf and respectively 1.5%wt Hf. The microhardness values for the experimental alloys have been in the range 154 ... 157 HV0.2. EDAX analyses have been performed to determine chemical composition on the oxide layer and in the bulk of sample and SEM analyze has been done to determine the microstructural features. The results have shown the capacity of FeCrAl alloy to form oxide layers, with different texture and rich in elements such as Al and Hf.

Processability evaluation of a Mo-containing FeCrAl alloy for seamless thin-wall tube fabrication

DOE PAGES

Sun, Zhiqian; Yamamoto, Yukinori

2017-06-10

The processability of a Mo-containing FeCrAl alloy (Fe-13Cr-5.2Al-2Mo base, in wt%), developed for accident-tolerant nuclear fuel claddings, was evaluated through a stepwise rolling process at 400 °C under two different inter-pass annealing conditions (i.e., 650 °C for 1 h and at 870 °C for 30 min). The inter-pass annealing at 870 °C easily softened the FeCrAl alloy; however, it led to the formation of coarse grains of ~200 µm. On the other hand, the FeCrAl alloy maintained elongated, deformed grains with the inter-pass annealing at 650 °C, but the annealed samples showed relatively high deformation resistance and strong texture. Importantmore » aspects concerning the processability and microstructural control of FeCrAl alloys, such as deformation inhomogeneity, texture development, and grain coarsening, were discussed. Optimized processing conditions were recommended, based on the results, to achieve desirable microstructures with balanced processability and mechanical properties.« less

WO x supported on γ-Al 2 O 3 with different morphologies as model catalysts for alkanol dehydration

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shi, Dachuan; Wang, Huamin; Kovarik, Libor

The distinctive morphological and surface characteristics of platelet-like γ-Al2O3 were compared to a regular, commercial γ-Al2O3. γ-Al2O3 platelets display dominant (110) surface facets and higher densities of coordinative unsaturated penta-coordinate Al3+ (Al3+penta) sites than regular γ-Al2O3, as measured by solid-state magic-angle spinning nuclear magnetic resonance spectroscopy (MAS NMR). Such Al3+penta sites are also the preferred surface anchoring sites for tungsten oxide (WOx) species consistent with NMR analysis indicating that these sites are consumed upon WOx adsorption. The higher Al3+penta density on γ-Al2O3 platelets leads to greater WOx dispersion (or smaller WOx clusters), as demonstrated by scanning transmission electron microscopy andmore » ultraviolet–visible spectroscopy, and WOx species at intermediate WOx surface concentration are the most active for the probe reaction of 2-butanol dehydration. WOx on γ-Al2O3 platelets approaches the highest turnover rates at higher surface densities than WOx on regular γ-Al2O3, yet with similar highest rate values for both series of catalysts. This indicates that different Al2O3 supports mainly affect the dispersion of supported WOx rather than the intrinsic reactivity of individual WOx clusters with similar size.« less

Piezo-tunnel effect in Al/Al2O3/Al junctions elaborated by atomic layer deposition

NASA Astrophysics Data System (ADS)

Rafael, R.; Puyoo, E.; Malhaire, C.

2017-11-01

In this work, the electrical transport in Al/Al2O3/Al junctions under mechanical stress is investigated in the perspective to use them as strain sensors. The metal/insulator/metal junctions are elaborated with a low temperature process (≤200 °C) fully compatible with CMOS back-end-of-line. The conduction mechanism in the structure is found to be Fowler-Nordheim tunneling, and efforts are made to extract the relevant physical parameters. Gauge factors up to -32.5 were found in the fabricated devices under tensile stress. Finally, theoretical mechanical considerations give strong evidence that strain sensitivity in Al/Al2O3/Al structures originates not only from geometrical deformations but also from the variation of interface barrier height and/or effective electronic mass in the tunneling oxide layer.

Influence of AlN(0001) Surface Reconstructions on the Wettability of an Al/AlN System: A First-Principle Study.

PubMed

Cao, Junhua; Liu, Yang; Ning, Xiao-Shan

2018-05-11

A successful application of a hot dip coating process that coats aluminum (Al) on aluminum nitride (AlN) ceramics, revealed that Al had a perfect wettability to the ceramics under specific circumstances, which was different from previous reports. In order to elucidate the mechanism that controlled the supernormal wetting phenomenon during the dip coating, a first-principle calculation of an Al(111)/AlN(0001) interface, based on the density functional theory (DFT), was employed. The wettability of the Al melt on the AlN(0001) surface, as well as the effect that the surface reconstruction of AlN and the oxygen adsorption had on Al for the adhesion and the wettability of the Al/AlN system, were studied. The results revealed that a LCM (laterally contracted monolayer) reconstruction could improve the adhesion and wettability of the system. Oxygen adsorption on the free surface of Al decreased the contact angle, because the adsorption reduced of the surface tension of Al. A prefect wetting was obtained only after some of the oxygen atoms adsorbed on the free surface of Al. The supernormal wetting phenomenon came from the surface reconstruction of the AlN and the adsorption of oxygen atoms on the Al melt surface.

Atmospheric effects and societal consequences of regional scale nuclear conflicts and acts of individual nuclear terrorism

NASA Astrophysics Data System (ADS)

Toon, O. B.; Turco, R. P.; Robock, A.; Bardeen, C.; Oman, L.; Stenchikov, G. L.

2007-04-01

We assess the potential damage and smoke production associated with the detonation of small nuclear weapons in modern megacities. While the number of nuclear warheads in the world has fallen by about a factor of three since its peak in 1986, the number of nuclear weapons states is increasing and the potential exists for numerous regional nuclear arms races. Eight countries are known to have nuclear weapons, 2 are constructing them, and an additional 32 nations already have the fissile material needed to build substantial arsenals of low-yield (Hiroshima-sized) explosives. Population and economic activity worldwide are congregated to an increasing extent in megacities, which might be targeted in a nuclear conflict. We find that low yield weapons, which new nuclear powers are likely to construct, can produce 100 times as many fatalities and 100 times as much smoke from fires per kt yield as previously estimated in analyses for full scale nuclear wars using high-yield weapons, if the small weapons are targeted at city centers. A single "small" nuclear detonation in an urban center could lead to more fatalities, in some cases by orders of magnitude, than have occurred in the major historical conflicts of many countries. We analyze the likely outcome of a regional nuclear exchange involving 100 15-kt explosions (less than 0.1% of the explosive yield of the current global nuclear arsenal). We find that such an exchange could produce direct fatalities comparable to all of those worldwide in World War II, or to those once estimated for a "counterforce" nuclear war between the superpowers. Megacities exposed to atmospheric fallout of long-lived radionuclides would likely be abandoned indefinitely, with severe national and international implications. Our analysis shows that smoke from urban firestorms in a regional war would rise into the upper troposphere due to pyro-convection. Robock et al. (2007) show that the smoke would subsequently rise deep into the stratosphere due

Japanese version of the ALS-FTD-Questionnaire (ALS-FTD-Q-J).

PubMed

Watanabe, Yasuhiro; Beeldman, Emma; Raaphorst, Joost; Izumi, Yuishin; Yoshino, Hiide; Masuda, Michihito; Atsuta, Naoki; Ito, Satoru; Adachi, Tadashi; Adachi, Yoshiki; Yokota, Osamu; Oda, Masaya; Hanashima, Ritsuko; Ogino, Mieko; Ichikawa, Hiroo; Hasegawa, Kazuko; Kimura, Hideki; Shimizu, Toshio; Aiba, Ikuko; Yabe, Hayato; Kanba, Makoto; Kusumi, Kimiyoshi; Aoki, Tetsuya; Hiroe, Yu; Watanabe, Hirohisa; Nishiyama, Kazutoshi; Nomoto, Masahiro; Sobue, Gen; Nakashima, Kenji

2016-08-15

Amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) share common clinical, genetic and neuropathological features. Some ALS patients have behavioral/personality changes, which could result in significant obstacles in the care provided by family members and caregivers. An easy screening tool would contribute greatly to the evaluation of these symptoms. We translated the ALS-FTD-Questionnaire, developed in the Netherlands, into Japanese (ALS-FTD-Q-J) and examined the clinimetric properties (internal consistency, construct and clinical validity). Patients with ALS and/or behavioral variant FTD (bvFTD) were evaluated alongside healthy controls in this multicenter study. All ALS patients, regardless of bvFTD status, were further evaluated by the frontal behavioral inventory (FBI) and for frontal/executive function, cognition, anxiety/depression, and motor functions. Data from 146 subjects were analyzed: ALS (92), ALS-bvFTD (6), bvFTD (16), and healthy controls (32). The internal consistency of the ALS-FTD-Q-J was good (Cronbach α=0.92). The ALS-FTD-Q-J showed construct validity as it exhibited a high correlation with the FBI (r=0.79). However, correlations were moderate with anxiety/depression and low with cognitive scales, in contrast to the original report, i.e. a moderate correlation with cognition and a low correlation with anxiety/depression. The ALS-FTD-Q-J discriminated ALS patients from (ALS-)bvFTD patients and controls. Thus, the ALS-FTD-Q-J is useful for evaluating Japanese ALS/FTD patients. Copyright © 2016 Elsevier B.V. All rights reserved.

Structural and optical properties of MgxAl1-xHy gradient thin films: a combinatorial approach

NASA Astrophysics Data System (ADS)

Gremaud, R.; Borgschulte, A.; Chacon, C.; van Mechelen, J. L. M.; Schreuders, H.; Züttel, A.; Hjörvarsson, B.; Dam, B.; Griessen, R.

2006-07-01

The structural, optical and dc electrical properties of MgxAl1-x (0.2≤x≤0.9) gradient thin films covered with Pd/Mg are investigated before and after exposure to hydrogen. We use hydrogenography, a novel high-throughput optical technique, to map simultaneously all the hydride forming compositions and the kinetics thereof in the gradient thin film. Metallic Mg in the MgxAl1-x layer undergoes a metal-to-semiconductor transition and MgH2 is formed for all Mg fractions x investigated. The presence of an amorphous Mg-Al phase in the thin film phase diagram enhances strongly the kinetics of hydrogenation. In the Al-rich part of the film, a complex H-induced segregation of MgH2 and Al occurs. This uncommon large-scale segregation is evidenced by metal and hydrogen profiling using Rutherford backscattering spectrometry and resonant nuclear analysis based on the reaction 1H(15N,αγ)12C. Besides MgH2, an additional semiconducting phase is found by electrical conductivity measurements around an atomic [Al]/[Mg] ratio of 2 (x=0.33). This suggests that the film is partially transformed into Mg(AlH4)2 at around this composition.

76 FR 16012 - STP Nuclear Operating Company, et al. South Texas Project, Units 1 and 2 Notice of Consideration...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-03-22

... NUCLEAR REGULATORY COMMISSION [NRC-2011-0063; Docket Nos. 50-498 And 50-499] STP Nuclear Operating... Facility Operating License, Proposed No Significant Hazards Consideration Determination, and Opportunity... on the NRC Web site and on the Federal rulemaking Web site http://www.regulations.gov . Because your...

3-Dimensional Microstructure of Al-Al3Ti Alloy Severely Deformed by ECAP

NASA Astrophysics Data System (ADS)

Sato, Hisashi; Hishikawa, Takahisa; Makino, Yuuki; Kunimine, Takahiro; Watanabe, Yoshimi

Microstructure of Al-Al3Ti alloy deformed by Equal-Channel-Angular Pressing (ECAP) is 3-dimensionally investigated. Especially, distribution of Al3Ti particles is focused in this study. The Al-Al3Ti alloy has coarse Al3Ti platelet particles in α-Al matrix. When the Al-Al3Ti alloy is deformed by ECAP under route A, fine Al3Ti platelet particles are observed. These Al3Ti platelet particles are aligned along to deformation axis, and its plane normal is perpendicular to the deformation axis. On the other hand, Al-Al3Ti alloy ECAPed under route Bc forms several groups consisted of fine Al3Ti platelet particles. Moreover, longitudinal size of the Al3Ti particle groups is close to that of initial Al3Ti particles with 4-pass ECAP specimen. These distribution behaviors of the Al3Ti particle can be explained by plastic flow of α-Al matrix. Finally, it is concluded that distribution of Al3Ti particle in Al-Al3Ti alloy by ECAP is controlled by plastic deformation of α-Al matrix.

Abu al-Layth al-Libi

DTIC Science & Technology

2015-02-01

in the region and apparently “showed brilliance in this regard through his perfect memorization , clever understanding, persistence, and patience...Taliban’s officials quietly left the capital without informing 73 Vernie Liebl, “Al-Qaida on the US Invasion of Afghanistan in Their Own Words ,” Small Wars... memorization . A talented and charismatic orator, he also used to deliver eulogies and `Id sermons. As to `Abdallah Sa`id al-Libi, his profile is similar

Defect structures in ordered intermetallics; grain boundaries and surfaces in FeAl, NiAl, CoAl and TiAl

NASA Astrophysics Data System (ADS)

Mutasa, Batsirai Manyara

Ordered intermetallics based on transition metal aluminides have been proposed as structural materials for advanced aerospace applications. The development of these materials, which have the advantages of low density and high operating temperatures, have been focused on the aluminides of titanium, nickel and iron. Though these materials exhibit attractive properties at elevated temperatures, their utilization is limited due to their propensity for low temperature fracture and susceptibility to decreased ductility due to environmental effects. A major embrittlement mechanism at ambient temperatures in these aluminides has been by the loss of cohesive strength at the interfaces (intergranular failure). This study focuses on this mechanism of failure, by undertaking a systematic study of the energies and structures of specific grain boundaries in some of these compounds. The relaxed atomistic grain boundary structures in B2 aluminides, FeAl, NiAl and CoAl and L10 gamma-TiAl were investigated using molecular statics and embedded atom potentials in order to explore general trends for a series of B2 compounds as well as TiAl. The potentials used correctly predict the proper mechanism of compositional disorder of these compounds. Using these potentials, point defects, free surface energies and various grain boundary structures of similar energies in three B2 compounds, FeAl, NiAl and CoAl were studied. These B2 alloys exhibited increasing anti-phase boundary energies respectively. The misorientations chosen for detailed study correspond to the Sigma5(310) and Sigma5(210) boundaries. These boundaries were investigated with consideration given to possible variations in the local chemical composition. The effects of both boundary stoichiometry and bulk stoichiometry on grain boundary energetics were also considered. Defect energies were calculated for boundaries contained in both stoichiometric and off-stoichiometric bulk. The surface energies for these aluminides were also

A Rechargeable Al/S Battery with an Ionic-Liquid Electrolyte.

PubMed

Gao, Tao; Li, Xiaogang; Wang, Xiwen; Hu, Junkai; Han, Fudong; Fan, Xiulin; Suo, Liumin; Pearse, Alex J; Lee, Sang Bok; Rubloff, Gary W; Gaskell, Karen J; Noked, Malachi; Wang, Chunsheng

2016-08-16

Aluminum metal is a promising anode material for next generation rechargeable batteries owing to its abundance, potentially dendrite-free deposition, and high capacity. The rechargeable aluminum/sulfur (Al/S) battery is of great interest owing to its high energy density (1340 Wh kg(-1) ) and low cost. However, Al/S chemistry suffers poor reversibility owing to the difficulty of oxidizing AlSx . Herein, we demonstrate the first reversible Al/S battery in ionic-liquid electrolyte with an activated carbon cloth/sulfur composite cathode. Electrochemical, spectroscopic, and microscopic results suggest that sulfur undergoes a solid-state conversion reaction in the electrolyte. Kinetics analysis identifies that the slow solid-state sulfur conversion reaction causes large voltage hysteresis and limits the energy efficiency of the system. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Growth of Ni-Al alloys on Ni(1 1 1), from Al deposits of various thicknesses: (II) Formation of NiAl over a Ni 3Al interfacial layer

NASA Astrophysics Data System (ADS)

Le Pévédic, S.; Schmaus, D.; Cohen, C.

2007-01-01

This paper describes the second part of a study devoted to the growth of thin Ni-Al alloys after deposition of Al on Ni(1 1 1). In the previous paper [S. Le Pévédic, D. Schmaus, C. Cohen, Surf. Sci. 600 (2006) 565] we have described the results obtained for ultra-thin Al deposits, leading, after annealing at 750 K, to an epitaxial layer of Ni 3Al(1 1 1). In the present paper we show that this regime is only observed for Al deposits smaller than 8 × 10 15 Al/cm 2 and we describe the results obtained for Al deposits exceeding this critical thickness, up to 200 × 10 15 Al/cm 2. Al deposition was performed at low temperature (around 130 K) and the alloying process was followed in situ during subsequent annealing, by Auger electron spectroscopy, low energy electron diffraction and ion beam analysis-channeling measurements, in an ultra-high vacuum chamber connected to a Van de Graaff accelerator. We evidence the formation, after annealing at 750 K, of a crystallographically and chemically well-ordered NiAl(1 1 0) layer (whose thickness depends on the deposited Al amount), over a Ni 3Al "interfacial" layer (whose thickness—about 18 (1 1 1) planes—is independent of the deposited Al amount). The NiAl overlayer is composed of three variants, at 120° from each other in the surface plane, in relation with the respective symmetries of NiAl(1 1 0) and Ni 3Al(1 1 1). The NiAl layer is relaxed (the lattice parameters of cc-B2 NiAl and fcc-L1 2 Ni 3Al differ markedly), and we have determined its epitaxial relationship. In the case of the thickest alloyed layer formed the results concerning the structure of the NiAl layer have been confirmed and refined by ex situ X-ray diffraction and information on its grain size has been obtained by ex situ Atomic Force Microscopy. The kinetics of the alloying process is complex. It corresponds to an heterogeneous growth leading, above the thin Ni 3Al interfacial layer, to a mixture of Al and NiAl over the whole Al film, up to the

Multidisciplinary ALS care improves quality of life in patients with ALS.

PubMed

Van den Berg, J P; Kalmijn, S; Lindeman, E; Veldink, J H; de Visser, M; Van der Graaff, M M; Wokke, J H J; Van den Berg, L H

2005-10-25

To examine the effect of multidisciplinary ALS care on the quality-of-life (QoL) in patients with ALS and their caregivers. In a cross-sectional study, 208 patients with ALS and their caregivers were interviewed. QoL was assessed using the 36-item Short Form Health Survey (SF-36) and two visual analogue scales (VAS). Criteria for multidisciplinary ALS care were: an ALS team headed by a consultant in rehabilitation medicine and consisting of at least a physical therapist, occupational therapist, speech pathologist, dietician and a social worker; use of the Dutch ALS consensus guidelines for ALS care; and at least six incident ALS patients per year. Clinical characteristics and functional loss of the 133 patients receiving multidisciplinary ALS care and the 75 patients receiving general ALS care were similar. The percentage of patients with adequate aids and appliances was higher in those with multidisciplinary ALS care (93.1 vs 81.3%, p = 0.008), whereas the number of visits to professional caregivers was similar in both groups. Patients in the multidisciplinary ALS care group had a better mental QoL on the SF-36 Mental Summary Score than those in the general care group (p = 0.01). The difference in QoL was most pronounced in the domains of Social Functioning and Mental Health, and was independent of the presence of aids and appliances. No significant differences were found in the SF-36 Physical Summary Score, VAS, or in QoL of caregivers of patients with ALS. High standard of care improves mental quality-of-life in patients with ALS.

New Insight into Nuclear Reactions in Solids

NASA Astrophysics Data System (ADS)

Miley, George H.

2003-04-01

Earlier work by the author disclosed evidence for nuclear transmutations in multi-layer thin-film Ni/Pd electrodes loaded to a high ratio of hydrogen/film metal using an electrolytic technique [1]. Non-natural isotopes abundances were found for select products. A distinctive characteristic of this and similar experiments by others is a product yield curve vs. mass with four high yield peaks distributed between low and high masses. Attempts to explain this observation have evolved around the original swimming electron layer (SEL) theory [2]. In addition, CR-39 track detector measurements have revealed low-level emission of 1.6 MeV protons and 16 MeV alpha particles from the front face of the thin film electrodes during runs [3]. Most recently Mitsubishi Corp. researchers have reported a real-time transmutation measurement using built-in XPS diagnostics where a surface layer of Sr-88 was transmuted into Mo-96 over a 200 hour run period during the diffusion of deuterium through a multi-layer thin-film Pd/CaO substrate [4]. Likewise in a companion experiment, Cs-133 was transmuted into Pr-141. These products exhibit a large deviation from natural isotopic abundance, and the characteristic signature is a mass change of 8 and charge change of 4. These various phenomena along with a preliminary theory involving SEL and orbital mixing will be presented. The objective is to provide a unified understanding of both types of experiments presented in Refs. 1 and 3. [1] G.H. Miley and J. A. Patterson, "Nuclear Transmutations in Thin-Film Nickel Coatings Undergoing Electrolysis," J. New Energy, 1, 3, 5-30 (1996). [2] H. Hora, et al., "Screening in Cold Fusion Derived from D D Reactions," Physics Ltrs. A, 175, 138-143, (1993). [3] A. Lipson, et al., "In-situ long - range alpha particles and X-ray detection in Pd thin film-cathodes during electrolysis in, Li2SO4/H2O, Bult. APS, 47, 1,Pt. II, 1219, Indianapolis, (2002). [4] Y. Iwamura, T. Itoh, et al., "Low energy nuclear reaction

The thermal expansion and thermophysical properties of an aluminum and Al/B4C composite

NASA Astrophysics Data System (ADS)

Gladkovsky, S. V.; Kamantsev, I. S.; Kuteneva, S. V.; Veselova, V. E.; Ryzhkov, M. A.

2017-12-01

The paper presents results of experimental studies of the thermal expansion and thermophysical properties of an Al/B4C composite with a boron carbide content of 20 wt% and technically pure aluminum in the temperature range from 100 to 600°C to evaluate the possible use of this composite as a neutron-protective material in the nuclear industry.

75 FR 15745 - Arizona Public Service Company, et al. Palo Verde Nuclear Generating Station, Units 1, 2, and 3...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-30

... rule's compliance date for all operating nuclear power plants, but noted that the Commission's... compliance date as documented in a letter from R.W. Borchardt, (NRC), to M.S. Fertel, (Nuclear Energy... Commission (NRC, or the Commission) now or hereafter in effect. The facility consists of three pressurized...

AlGaN-based ultraviolet light-emitting diodes on sputter-deposited AlN templates with epitaxial AlN/AlGaN superlattices

NASA Astrophysics Data System (ADS)

Zhao, Lu; Zhang, Shuo; Zhang, Yun; Yan, Jianchang; Zhang, Lian; Ai, Yujie; Guo, Yanan; Ni, Ruxue; Wang, Junxi; Li, Jinmin

2018-01-01

We demonstrate AlGaN-based ultraviolet light-emitting diodes (UV-LEDs) grown by metalorganic chemical vapor deposition (MOCVD) on sputter-deposited AlN templates upon sapphire substrates. An AlN/AlGaN superlattices structure is inserted as a dislocation filter between the LED structure and the AlN template. The full width at half maximum values for (0002) and (10 1 bar 2) X-ray rocking curves of the n-type Al0.56Ga0.44N layer are 513 and 1205 arcsec, respectively, with the surface roughness of 0.52 nm. The electron concentration and mobility measured by Hall measurement are 9.3 × 1017cm-3 and 54 cm2/V·s at room temperature, respectively. The light output power of a 282-nm LED reaches 0.28 mW at 20 mA with an external quantum efficiency of 0.32%. And the values of leakage current and forward voltage of the LEDs are ∼3 nA at -10 V and 6.9 V at 20 mA, respectively, showing good electrical performance. It is expected that the cost of the UV-LED can be reduced by using sputter-deposited AlN template.

On the Potential of MAX phases for Nuclear Applications

NASA Astrophysics Data System (ADS)

Tallman, Darin Joseph

Materials within nuclear reactors experience some of the harshest environments currently known to man, including long term operation in extreme temperatures, corrosive media, and fast neutron fluences with up to 100 displacements per atom, dpa. In order to improve the efficiency and safety of current and future reactors, new materials are required to meet these harsh demands. The M n+1AXn phases, a growing family of ternary nano-layered ceramics, possess a desirable combination of metallic and ceramic properties. They are composed of an early transition metal (M), a group 13--16 element (A), and carbon and/or nitrogen (X). The MAX phases are being proposed for use in such extreme environments because of their unique combination of high fracture toughness values and thermal conductivities, machinability, oxidation resistance, and ion irradiation damage tolerance. Previous ion irradiation studies have shown that Ti3SiC2 and Ti3AlC2 resist irradiation damage, maintaining crystallinity up to 50 dpa. The aim of this work was to explore the effect of neutron irradiation, up to 9 dpa and at temperatures of 100 to 1000 °C, on select MAX phases for the first time. The MAX phases Ti3SiC2, Ti 3AlC2, Ti2AlC, and Ti2AlN were synthesized, and irradiated in test reactors that simulate in-pile conditions of nuclear reactors. X-ray diffraction, XRD, pattern refinements of samples revealed a distortion of the crystal lattice after low temperature irradiation, which was not observed after high temperature irradiations. Additionally, the XRD results indicated that Ti3AlC2 and Ti2AlN dissociated after relatively low neutron doses. This led us to focus on Ti 3SiC2 and Ti2AlC. For the first time, dislocation loops were observed in Ti3SiC 2 and Ti2AlC as a result of neutron irradiation. At 1 x 1023 loops/m3, the loop density in Ti2 AlC after irradiation to 0.1 dpa at 700°C was 1.5 orders of magnitude greater than that observed in Ti3SiC2, at 3 x 1021 loops/m3. The Ti2AlC composition

Cyclic oxidation resistance of a reaction milled NiAl-AlN composite

NASA Technical Reports Server (NTRS)

Lowell, Carl E.; Barrett, Charles A.; Whittenberger, J. D.

1990-01-01

Based upon recent mechanical property tests a NiAl-AlN composite produced by cryomilling has very attractive high temperature strength. This paper focuses on the oxidation resistance of the NiAl-AlN composite at 1473 and 1573 K as compared to that of Ni-47Al-0.15Zr, one of the most oxidation resistant intermetallics. The results of cyclic oxidation tests show that the NiAl-AlN composite has excellent properties although not quite as good as those of Ni-47Al-0.15Zr. The onset of failure of the NiAl-AlN was unique in that it was not accompanied by a change in scale composition from alumina to less protective oxides. Failure in the composite appears to be related to the entrapment of AlN particles within the alumina scale.

ALS-Plus Syndrome: Non-Pyramidal Features in a Large ALS Cohort

PubMed Central

McCluskey, Leo; Vandriel, Shannon; Elman, Lauren; Van Deerlin, Vivianna M.; Powers, John; Boller, Ashley; Wood, Elisabeth McCarty; Woo, John; McMillan, Corey T.; Rascovsky, Katya; Grossman, Murray

2014-01-01

Objective Autopsy studies show widespread pathology in amyotrophic lateral sclerosis (ALS), but clinical surveys of multisystem disease in ALS are rare. We investigated ALS-Plus syndrome, an understudied group of patients with clinical features extending beyond pyramidal and neuromuscular systems with or without cognitive/behavioral deficits. Methods In a large, consecutively-ascertained cohort of 550 patients with ALS, we documented atypical clinical manifestations. Genetic screening for C9orf72 hexanucleotide expansions was performed in 343 patients, and SOD1, TARDBP, and VCP were tested in the subgroup of patients with a family history of ALS. Gray matter and white matter imaging was available in a subgroup of 30 patients. Results Seventy-five (13.6%) patients were identified with ALS-Plus syndrome. We found disorders of ocular motility, cerebellar, extrapyramidal and autonomic functioning. Relative to those without ALS-Plus, cognitive impairment (8.0% vs 2.9%, p=0.029), bulbar-onset (49.3% vs 23.2%, p<0.001), and pathogenic mutations (20.0% vs 8.4%, p=0.015) were more than twice as common in ALS-Plus. Survival was significantly shorter in ALS-Plus (29.66 months vs 42.50 months, p=0.02), regardless of bulbar-onset or mutation status. Imaging revealed significantly greater cerebellar and cerebral disease in ALS-Plus compared to those without ALS-Plus. Conclusions ALS-Plus syndrome is not uncommon, and the presence of these atypical features is consistent with neuropathological observations that ALS is a multisystem disorder. ALS-Plus syndrome is associated with increased risk for poor survival and the presence of a pathogenic mutation. PMID:25086858

[Researchers training in the context of the collaborative projects: experiences of Instituto de Medicina Tropical "Alexander von Humbolt", Universidad Peruana Cayetano Heredia].

PubMed

Gotuzzo, Eduardo; González, Elsa; Verdonck, Kristien

2010-09-01

Research is a main element for human and social development. Under this point of view, it involves particular challenges and opportunities for the so-called "developing countries". An approach for those challenges and opportunities comes from the analysis of two interrelated activities; the training of new researchers and the research development with institutions or researchers which are external to the institution ("collaborative research"). Both activities are essential for the consolidation, widening and updating of the institutional capabilities for scientific production. We present here the experiences of the Instituto de Medicina Tropical "Alexander von Humboldt" of the Universidad Peruana Cayetano Heredia, in relation to the training of new researchers, we discuss the four elements we consider key for this process; the promotion of stimulating environments for research, the proactive identification of fellows, the complementary advice and networks consolidation; and we analyze three successful models of international collaboration for the training of new researchers under different institutional approaches.

Rapid regulation of nuclear proteins by rapamycin-induced translocation in fission yeast

PubMed Central

Ding, Lin; Laor, Dana; Weisman, Ronit; Forsburg, Susan L

2014-01-01

Genetic analysis of protein function requires a rapid means of inactivating the gene under study. Typically this exploits temperature sensitive mutations, or promoter shut-off techniques. We report the adaptation to Schizosaccharomyces pombe of the Anchor Away technique, originally designed in budding yeast (Haruki et al., 2008a). This method relies on a rapamycin-mediated interaction between the FRB and FKBP12 binding domains, to relocalize nuclear proteins of interest to the cytoplasm. We demonstrate a rapid nuclear depletion of abundant proteins as proof-of-principle. PMID:24733494

Valence subband coupling effect on polarization of spontaneous emissions from Al-rich AlGaN/AlN quantum wells.

PubMed

Lu, Huimin; Yu, Tongjun; Yuan, Gangcheng; Jia, Chuanyu; Chen, Genxiang; Zhang, Guoyi

2012-12-03

The optical polarization properties of Al-rich AlGaN/AlN quantum wells (QWs) were investigated using the theoretical model based on the k·p method. Numerical results show that there is valence subband coupling which can influence the peak emission wavelength and emission intensity for TE and TM polarization components from Al-rich AlGaN/AlN QWs. Especially the valence subband coupling could be strong enough when CH1 is close to HH1 and LH1 subbands to modulate the critical Al content switching dominant emissions from TE to TM polarization. It is believed that the valence subband coupling may give important influence on polarization properties of spontaneous emissions and should be considered in designing high efficiency AlGaN-based ultraviolet (UV) LEDs.

Modulating optical polarization properties of Al-rich AlGaN/AlN quantum well by controlling wavefunction overlap

NASA Astrophysics Data System (ADS)

Chen, X. J.; Yu, T. J.; Lu, H. M.; Yuan, G. C.; Shen, B.; Zhang, G. Y.

2013-10-01

Using modified k.p perturbation method, the optical polarization properties of Al-rich AlGaN/AlN quantum wells (QWs) are studied. It is found that change of wavefunction overlaps between conduction band and valance subbands of heavy hole, light hole, and crystal-field split off hole is different. Such difference leads to the overturn of polarization degree and modulates optical polarization properties as well width and strain vary. This prompts that changing wavefunction overlaps of electron and hole can lead to a way to modulate optical polarization properties of Al-rich AlGaN/AlN QWs, on no condition that valence band order changes.

Effect of AlB2 on the P-threshold in Al-Si alloy

NASA Astrophysics Data System (ADS)

Wu, Yuying; Liu, Xiangfa

2018-06-01

The nucleation of primary Si in Al-Si alloys has been investigated in this work. It was found that there was a threshold concentration of P, below which AlP can not heterogeneous nucleate primary Si in Al-12 wt%Si alloy. AlB2 can not nucleate primary Si directly, but the presence of AlB2 may assist the nucleation of AlP leading to the nucleation of primary Si particles. In addition, with addition of AlB2, the nucleation efficiency of AlP can be improved in Al-18 wt%Si alloy. The orientation relationship between AlB2 and AlP has been calculated, and the adsorption model for AlB2 and AlP was proposed in this work.

LLNL Results from CALIBAN-PROSPERO Nuclear Accident Dosimetry Experiments in September 2014

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lobaugh, M. L.; Hickman, D. P.; Wong, C. W.

2015-05-21

Lawrence Livermore National Laboratory (LLNL) uses thin neutron activation foils, sulfur, and threshold energy shielding to determine neutron component doses and the total dose from neutrons in the event of a nuclear criticality accident. The dosimeter also uses a DOELAP accredited Panasonic UD-810 (Panasonic Industrial Devices Sales Company of America, 2 Riverfront Plaza, Newark, NJ 07102, U.S.A.) thermoluminescent dosimetery system (TLD) for determining the gamma component of the total dose. LLNL has participated in three international intercomparisons of nuclear accident dosimeters. In October 2009, LLNL participated in an exercise at the French Commissariat à l’énergie atomique et aux énergies alternativesmore » (Alternative Energies and Atomic Energy Commission- CEA) Research Center at Valduc utilizing the SILENE reactor (Hickman, et.al. 2010). In September 2010, LLNL participated in a second intercomparison at CEA Valduc, this time with exposures at the CALIBAN reactor (Hickman et al. 2011). This paper discusses LLNL’s results of a third intercomparison hosted by the French Institut de Radioprotection et de Sûreté Nucléaire (Institute for Radiation Protection and Nuclear Safety- IRSN) with exposures at two CEA Valduc reactors (CALIBAN and PROSPERO) in September 2014. Comparison results between the three participating facilities is presented elsewhere (Chevallier 2015; Duluc 2015).« less

Origins of low resistivity in Al ion-implanted ZnO bulk single crystals

NASA Astrophysics Data System (ADS)

Oga, T.; Izawa, Y.; Kuriyama, K.; Kushida, K.; Kinomura, A.

2011-06-01

The origins of low resistivity in Al ion-implanted ZnO bulk single crystals are studied by combining Rutherford backscattering spectroscopy (RBS), nuclear reaction analysis (NRA), photoluminescence (PL), and Van der Pauw methods. The Al-ion implantation (peak concentration: 2.6 × 1020cm-3) into ZnO is performed using a multiple-step energy. The resistivity decreases from ˜104 Ω cm for un-implanted ZnO to 1.4 × 10-1 Ω cm for as-implanted, and reaches 6.0 × 10-4 Ω cm for samples annealed at 1000 °C. RBS and NRA measurements for as-implanted ZnO suggest the existence of the lattice displacement of Zn (Zni) and O (Oi), respectively. After annealing at 1000 °C, the Zni related defects remain and the Oi related defects disappear. The origin of the low resistivity in the as-implanted sample is attributed to the Zni (˜30 meV [Look et al., Phys. Rev. Lett. 82, 2552 (1999)]). In contrast, the origin of the low resistivity in the sample annealed at 1000 °C is assigned to both of the Zni related defects and the electrically activated Al donor. A new PL emission appears at around 3.32 eV after annealing at 1000 °C, suggesting electrically activated Al donors.

Suppression of nuclear spin bath fluctuations in self-assembled quantum dots induced by inhomogeneous strain

PubMed Central

Chekhovich, E.A.; Hopkinson, M.; Skolnick, M.S.; Tartakovskii, A.I.

2015-01-01

Interaction with nuclear spins leads to decoherence and information loss in solid-state electron-spin qubits. One particular, ineradicable source of electron decoherence arises from decoherence of the nuclear spin bath, driven by nuclear–nuclear dipolar interactions. Owing to its many-body nature nuclear decoherence is difficult to predict, especially for an important class of strained nanostructures where nuclear quadrupolar effects have a significant but largely unknown impact. Here, we report direct measurement of nuclear spin bath coherence in individual self-assembled InGaAs/GaAs quantum dots: spin-echo coherence times in the range 1.2–4.5 ms are found. Based on these values, we demonstrate that strain-induced quadrupolar interactions make nuclear spin fluctuations much slower compared with lattice-matched GaAs/AlGaAs structures. Our findings demonstrate that quadrupolar effects can potentially be used to engineer optically active III-V semiconductor spin-qubits with a nearly noise-free nuclear spin bath, previously achievable only in nuclear spin-0 semiconductors, where qubit network interconnection and scaling are challenging. PMID:25704639

Ultra-High Precision Half-Life Measurement for the Superallowed &+circ; Emitter ^26Al^m

NASA Astrophysics Data System (ADS)

Finlay, P.; Demand, G.; Garrett, P. E.; Leach, K. G.; Phillips, A. A.; Sumithrarachchi, C. S.; Svensson, C. E.; Triambak, S.; Grinyer, G. F.; Leslie, J. R.; Andreoiu, C.; Cross, D.; Austin, R. A. E.; Ball, G. C.; Bandyopadhyay, D.; Djongolov, M.; Ettenauer, S.; Hackman, G.; Pearson, C. J.; Williams, S. J.

2009-10-01

The calculated nuclear structure dependent correction for ^26Al^m (δC-δNS= 0.305(27)% [1]) is smaller by nearly a factor of two than the other twelve precision superallowed cases, making it an ideal case to pursue a reduction in the experimental errors contributing to the Ft value. An ultra-high precision half-life measurement for the superallowed &+circ; emitter ^26Al^m has been made at the Isotope Separator and Accelerator (ISAC) facility at TRIUMF in Vancouver, Canada. A beam of ˜10^5 ^26Al^m/s was delivered in October 2007 and its decay was observed using a 4π continuous gas flow proportional counter as part of an ongoing experimental program in superallowed Fermi β decay studies. With a statistical precision of ˜0.008%, the present work represents the single most precise measurement of any superallowed half-life to date. [4pt] [1] I.S. Towner and J.C. Hardy, Phys. Rev. C 79, 055502 (2009).

Ultra-High Precision Half-Life Measurement for the Superallowed &+circ; Emitter ^26Al^m

NASA Astrophysics Data System (ADS)

Finlay, P.; Demand, G.; Garrett, P. E.; Leach, K. G.; Phillips, A. A.; Sumithrarachchi, C. S.; Svensson, C. E.; Triambak, S.; Ball, G. C.; Bandyopadhyay, D.; Djongolov, M.; Ettenauer, S.; Hackman, G.; Pearson, C. J.; Williams, S. J.; Andreoiu, C.; Cross, D.; Austin, R. A. E.; Grinyer, G. F.; Leslie, J. R.

2008-10-01

The calculated nuclear structure dependent correction for ^26Al^m (δC-δNS= 0.305(27)% [1]) is smaller by nearly a factor of two than the other twelve precision superallowed cases, making it an ideal case to pursue a reduction in the experimental errors contributing to the Ft value. An ultra-high precision half-life measurement for the superallowed &+circ; emitter ^26Al^m has been made using a 4π continuous gas flow proportional counter as part of an ongoing experimental program in superallowed Fermi β decay studies at the Isotope Separator and Accelerator (ISAC) facility at TRIUMF in Vancouver, Canada, which delivered a beam of ˜10^5 ^26Al^m/s in October 2007. With a statistical precision of ˜0.008%, the present work represents the single most precise measurement of any superallowed half-life to date. [1] I.S. Towner and J.C. Hardy, Phys. Rev. C 77, 025501 (2008).

[The anti-philosophical anthropology in the Hippocratic treatise De Vetere Medicina (On Ancient Medicine)].

PubMed

Imai, Masahiro

2007-01-01

The Hippocratic treatise De Vetere Medicina (On Ancient Medicine) has been the focus of attention among classical scholars and historians of medicine. The author attacks in ch. 20 doctors and sophists who base their own medical theories and methods on philosophical anthropology taken from the contemporary natural philosophers. Many attempts have been made to elucidate, as opposed to their philosophical inquiry into human nature, the author's way of understanding it, which still remains unclear. I draw attention to the following points to make it clear that the conceptual framework of the author's medical anthropology is different from theirs. Their philosophical inquiry into human nature has its starting point in fundamental element(s), from which human beings were originally formed. The author focuses on human beings as existent in their present states, whose conditions and functions must be investigated through interrelations between them and their external factors, such as foods and drinks. A medical investigation into the interrelations will give us a scientific idea about human body, whose constituents are taken to be a large number of humors, reacting against some external factors and accordingly making us feel pain. This may presuppose that, in the author's medical anthropology, human body is conceptually demarcated as the physical or material aspect of human being, within which all physiological events depending on external factors and the humors take place. In their philosophical anthropology, however, human body doesn't seem to have been clearly conceptualized as such, because our experience of feeling pain should be judged to take place within the actions of the fundamental element(s), which must be supposed to constitute our cognitive self.

Mg-Al and Zn-Al Layered Double Hydroxides Promote Dynamic Expression of Marker Genes in Osteogenic Differentiation by Modulating Mitogen-Activated Protein Kinases.

PubMed

Kang, Ha Ram; da Costa Fernandes, Célio Junior; da Silva, Rodrigo Augusto; Constantino, Vera Regina Leopoldo; Koh, Ivan Hong Jun; Zambuzzi, Willian F

2018-02-01

The effect of LDH samples comprised of chloride anions intercalated between positive layers of magnesium/aluminum (Mg-Al LDH) or zinc/aluminum (Zn-Al LDH) chemical composition on pre-osteoblast performance is investigated. Non-cytotoxic concentrations of both LDHs modulated pre-osteoblast adhesion by triggering cytoskeleton rearrangement dependent on recruiting of Cofilin, which is modulated by the inhibition of the Protein Phosphatase 2A (PP2A), culminating in osteoblast differentiation with a significant increase of osteogenic marker genes. The alkaline phosphatase (ALP) and bone sialoprotein (BSP) are significantly up-modulated by both LDHs; however, Mg-Al LDH nanomaterial promoted even more significance than both experimental controls, while the phosphorylations of mitogen-activated protein kinase (MAPKs)- extracellular signal-regulated kinases (ERK) and c-Jun N-terminal kinase (JNK) significantly increased. MAPK signaling is necessary to activate Runt-related transcription factor 2 (RUNX2) gene. Concomitantly, it is also investigated whether challenged osteoblasts are able to modulate osteoclastogenesis by investigating both osteoprotegerin (OPG) and Receptor activator of nuclear factor kappa-ligand (RANKL) in this model; a dynamic reprogramming of both these genes is found, suggesting LDHs in modulating osteoclastogenesis. These results suggest that LDHs interfere in bone remodeling, and they can be considered as nanomaterials in graft-based bone healing or drug-delivery materials for bone disorders. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

High temperature deformation of NiAl and CoAl

NASA Technical Reports Server (NTRS)

Nix, W. D.

1982-01-01

The high temperature mechanical properties of the aluminides are reviewed with respect to their potential as high temperature structural materials. It is shown that NiAl and CoAl are substantially stronger than the pure metals Ni and Co at high temperatures and approach the strength of some superalloys, particularly when those superalloys are tested in "weak" directions. The factors that limit and control the high temperature strengths of NiAl and CoAl are examined to provide a basis for the development of intermetallic alloys of this type.

Preliminary Results on FeCrAl Alloys in the As-received and Welded State Designed to Have Enhanced Weldability and Radiation Tolerance

DOE Office of Scientific and Technical Information (OSTI.GOV)

Field, Kevin G.; Gussev, Maxim N.; Hu, Xunxiang

2015-09-30

The present report summarizes and discusses the recent results on developing a modern, nuclear grade FeCrAl alloy designed to have enhanced radiation tolerance and weldability. The alloys used for these investigations are modern FeCrAl alloys based on a Fe-13Cr-5Al-2Mo-0.2Si-0.05Y alloy (in wt.%, designated C35M). Development efforts have focused on assessing the influence of chemistry and microstructure on the fabricability and performance of these newly developed alloys. Specific focus was made to assess the weldability, thermal stability, and radiation tolerance.

The structure-directed effect of Al-based metal–organic frameworks on fabrication of alumina by thermal treatment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Dandan, E-mail: liudandan_upc@126.com; Dai, Fangna, E-mail: fndai@upc.edu.cn; Collage of Science, China University of Petroleum

2015-05-15

Highlights: • We use Al-MOFs as precursor in the fabrication process of mesoporous alumina by thermal treatment. • The obtained mesoporous alumina has dual pore system and five-fold aluminum. • The aluminum building units in the precursor show structure-directed effect on the formation of alumina. - Abstract: In this work, the block-shaped Al-based metal–organic frameworks (Al-MOFs) MIL-53 have been synthesized by hydrothermal method. To detect the correlation between the structure of Al-MOFs and the formation of alumina, the ligands are eliminated by thermal treatment. MIL-53 and the calcination products were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR),more » scanning electron microscope (SEM), transmission electron microscopy (TEM), nitrogen adsorption–desorption and solid-state {sup 27}Al nuclear magnetic resonance ({sup 27}Al NMR). It was found that after calcination, the block-shaped Al-MOFs precursor turns into high-crystallinity mesoporous alumina nanosheets, and the thermal treatment product γ-alumina possesses a dual pore system and a large surface area (146 m{sup 2}/g), with five-fold aluminum. During the thermal treatment process, the structure of MIL-53 and its secondary building units have structure-directed effect in the formation of alumina.« less

Atomistic Modeling of RuAl and (RuNi) Al Alloys

NASA Technical Reports Server (NTRS)

Gargano, Pablo; Mosca, Hugo; Bozzolo, Guillermo; Noebe, Ronald D.; Gray, Hugh R. (Technical Monitor)

2002-01-01

Atomistic modeling of RuAl and RuAlNi alloys, using the BFS (Bozzolo-Ferrante-Smith) method for alloys is performed. The lattice parameter and energy of formation of B2 RuAl as a function of stoichiometry and the lattice parameter of (Ru(sub 50-x)Ni(sub x)Al(sub 50)) alloys as a function of Ni concentration are computed. BFS based Monte Carlo simulations indicate that compositions close to Ru25Ni25Al50 are single phase with no obvious evidence of a miscibility gap and separation of the individual B2 phases.

Nuclear starburst activity induced by elongated bulges in spiral galaxies

NASA Astrophysics Data System (ADS)

Kim, Eunbin; Kim, Sungsoo S.; Choi, Yun-Young; Lee, Gwang-Ho; de Grijs, Richard; Lee, Myung Gyoon; Hwang, Ho Seong

2018-06-01

We study the effects of bulge elongation on the star formation activity in the centres of spiral galaxies using the data from the Sloan Digital Sky Survey Data Release 7. We construct a volume-limited sample of face-on spiral galaxies with Mr < -19.5 mag at 0.02 ≤z< 0.055 by excluding barred galaxies, where the aperture of the SDSS spectroscopic fibre covers the bulges of the galaxies. We adopt the ellipticity of bulges measured by Simard et al. (2011) who performed two-dimensional bulge+disc decompositions using the SDSS images of galaxies, and identify nuclear starbursts using the fibre specific star formation rates derived from the SDSS spectra. We find a statistically significant correlation between bulge elongation and nuclear starbursts in the sense that the fraction of nuclear starbursts increases with bulge elongation. This correlation is more prominent for fainter and redder galaxies, which exhibit higher ratios of elongated bulges. We find no significant environmental dependence of the correlation between bulge elongation and nuclear starbursts. These results suggest that non-axisymmetric bulges can efficiently feed the gas into the centre of galaxies to trigger nuclear starburst activity.

An investigation of FeCrAl cladding behavior under normal operating and loss of coolant conditions

DOE PAGES

Gamble, Kyle A.; Barani, Tommaso; Pizzocri, David; ...

2017-04-30

Iron-chromium-aluminum (FeCrAl) alloys are candidates to be used as nuclear fuel cladding for increased accident tolerance. An analysis of the response of FeCrAl under normal operating and loss of coolant conditions has been performed using fuel performance modeling. In particular, recent information on FeCrAl material properties and phenomena from separate effects tests has been implemented in the BISON fuel performance code and analyses of integral fuel rod behavior with FeCrAl cladding have been performed. BISON simulations included both light water reactor normal operation and loss-of-coolant accidental transients. In order to model fuel rod behavior during accidents, a cladding failure criterionmore » is desirable. For FeCrAl alloys, a failure criterion is developed using recent burst experiments under loss of coolant like conditions. The added material models are utilized to perform comparative studies with Zircaloy-4 under normal operating conditions and oxidizing and non-oxidizing out-of-pile loss of coolant conditions. The results indicate that for all conditions studied, FeCrAl behaves similarly to Zircaloy-4 with the exception of improved oxidation performance. Here, further experiments are required to confirm these observations.« less

Design of alumina forming FeCrAl steels for lead or lead-bismuth cooled fast reactors

NASA Astrophysics Data System (ADS)

Lim, Jun; Hwang, Il Soon; Kim, Ji Hyun

2013-10-01

Iron-chromium-aluminum alloys containing 15-20 wt.% Cr and 4-6 wt.% Al have shown excellent corrosion resistance in the temperature range up to 600 °C or higher in liquid lead and lead-bismuth eutectic environments by the formation of protective Al2O3 layers. However, the higher Cr and Al concentrations in ferritic alloys could be problematic because of severe embrittlement in the manufacturing process as well as in service, caused by the formation of brittle phases. For this reason, efforts worldwide have so far mainly focused on the development of aluminizing surface treatments. However, aluminizing surface treatments have major disadvantages of cost, processing difficulties and reliability issues. In this study, a new FeCrAl alloy is proposed for structural materials in lead and lead-bismuth cooled nuclear applications. The alloy design relied on corrosion experiments in high temperature lead and lead-bismuth eutectic environments and computational thermodynamic calculations using the commercial software, JMatPro. The design of new alloys has focused on the optimization of Cr and Al levels for the formation of an external Al2O3 layer which can provide excellent oxidation and corrosion resistance in liquid lead alloys in the temperature range 300-600 °C while still retaining workable mechanical properties.

An investigation of FeCrAl cladding behavior under normal operating and loss of coolant conditions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gamble, Kyle A.; Barani, Tommaso; Pizzocri, David

Iron-chromium-aluminum (FeCrAl) alloys are candidates to be used as nuclear fuel cladding for increased accident tolerance. An analysis of the response of FeCrAl under normal operating and loss of coolant conditions has been performed using fuel performance modeling. In particular, recent information on FeCrAl material properties and phenomena from separate effects tests has been implemented in the BISON fuel performance code and analyses of integral fuel rod behavior with FeCrAl cladding have been performed. BISON simulations included both light water reactor normal operation and loss-of-coolant accidental transients. In order to model fuel rod behavior during accidents, a cladding failure criterionmore » is desirable. For FeCrAl alloys, a failure criterion is developed using recent burst experiments under loss of coolant like conditions. The added material models are utilized to perform comparative studies with Zircaloy-4 under normal operating conditions and oxidizing and non-oxidizing out-of-pile loss of coolant conditions. The results indicate that for all conditions studied, FeCrAl behaves similarly to Zircaloy-4 with the exception of improved oxidation performance. Here, further experiments are required to confirm these observations.« less

Overview of insoluble radioactive cesium particles emitted from the Fukushima Dai-ichi Nuclear Power Station

NASA Astrophysics Data System (ADS)

Satou, Yukihiko

2017-04-01

In the early stage of the Fukushima Dai-ichi Nuclear Power Station (F1NPS) accident, number of spot type contamination has been observed in computed autoradiography (Kashimura 2013, Shibata 2013, Satou 2014). It's means presence of radioactive particles, however, insoluble cesium particle was overlooked because cesium, which is dominant radioactive element in the accident, becomes ionized in the environment. Adachi et al. (2013) showed presence of cesium (Cs)-bearing particles within air dust sample collected at Tsukuba, 170 km south from the Fukushima site, in midnight of 14 to morning of 15 March 2011. These particles were micrometer order small particles and Cs was could be detectable as element using an energy dispersive X-ray spectroscopy (EDX). However, other radioactive elements such as Co-60, Ru-103 and uranium, which were dominant element of radioactive particles delivered from Chernobyl accident, could not detected. Abe et al. (2014) employed a synchrotron radiation (SR)-micro(μ)-X-ray analysis to the Cs-bearing particles, and they were concluded that (1) contained elements derived from nuclear fission processes and from nuclear reactor and fuel materials; (2) were amorphous; (3) were highly oxidized; and (4) consisted of glassy spherules formed from a molten mixture of nuclear fuel and reactor material. In addition, Satou et al. (2016) and Yamaguchi et al. (2016) disclosed that silicate is main component of Cs-bearing particles. Satou et al. (2015) discovered two types of radioactive particles from soil samples collected in the vicinity of the F1NPS. These particles were remained in the natural environment more than four years, silicate is main component in common of each group particles. Group A particles were very similar to Cs-bearing particles reported by Adachi et al. except particle shape. On the other hand, group B is big particles found in north area from the F1NPS, and the strongest particles contained 20 kBq of Cs-137 within a particle

Future intrusion of oxygenated glacial meltwaters into the Fennoscandian shield: a possibility to consider in performance assessments for nuclear-waste disposal sites?: Chapter 6

USGS Publications Warehouse

Glynn, Pierre

2008-01-01

Provost et al. (1998) and Glynn and Voss (1999; also published in Glynn et al., 1999) considered the possibility that during future glaciations, oxygenated glacial meltwaters from two- to three-kilometer thick ice sheets could potentially intrude to the 500 m depth of planned nuclear-waste repositories. This possibility has been of concern because of potential negative effects on the stability of the repository engineered environment, and because of the potential mobilization of radionuclides should the oxygenated waters come into contact with the radioactive waste. The above reports argued that given the current state of knowledge, it was hard to discount the possibility that oxygenated waters could penetrate to repository level depth. The reports also suggested that oxidizing conditions might be present in the fractured rock environment for significant amounts of time, on the order of thousands to tens of thousands of years. In some earlier reports, Swedish and Finnish governmental agencies in charge of nuclear-waste disposal had considered the possibility that oxygenated meltwaters might intrude to the repository depth (SKI: 1992; Martinerie et al, 1992; Ahonen and Vieno, 1994). Subsequent to the publication of Provost et al. (1998), Glynn et al. (1999) and Glynn and Voss (1999), the Swedish Nuclear Fuel and Waste Handling Company (SKB) commissioned efforts to examine more thoroughly the possibilities that oxygenated meltwaters might occur under ice-sheet conditions and intrude to the repository depth.

Al6H18: A baby crystal of γ-AlH3

NASA Astrophysics Data System (ADS)

Kiran, B.; Kandalam, Anil K.; Xu, Jing; Ding, Y. H.; Sierka, M.; Bowen, K. H.; Schnöckel, H.

2012-10-01

Using global-minima search methods based on the density functional theory calculations of (AlH3)n (n = 1-8) clusters, we show that the growth pattern of alanes for n ≥ 4 is dominated by structures containing hexa-coordinated Al atoms. This is in contrast to the earlier studies where either linear or ring structures of AlH3 were predicted to be the preferred structures in which the Al atoms can have a maximum of five-fold coordination. Our calculations also reveal that the Al6H18 cluster, with its hexa-coordination of the Al atoms, resembles the unit-cell of γ-AlH3, thus Al6H18 is designated as the "baby crystal." The fragmentation energies of the (AlH3)n (n = 2-8) along with the dimerization energies for even n clusters indicate an enhanced stability of the Al6H18 cluster. Both covalent (hybridization) and ionic (charge) contribution to the bonding are the driving factors in stabilizing the isomers containing hexa-coordinated Al atoms.

Direct Observation of Lattice Aluminum Environments in Li Ion Cathodes LiNi1-y-zCoyAlzO2 and Al-Doped LiNixMnyCozO2 via (27)Al MAS NMR Spectroscopy.

PubMed

Dogan, Fulya; Vaughey, John T; Iddir, Hakim; Key, Baris

2016-07-06

Direct observations of local lattice aluminum environments have been a major challenge for aluminum-bearing Li ion battery materials, such as LiNi1-y-zCoyAlzO2 (NCA) and aluminum-doped LiNixMnyCozO2 (NMC). (27)Al magic angle spinning (MAS) nuclear magnetic resonance (NMR) spectroscopy is the only structural probe currently available that can qualitatively and quantitatively characterize lattice and nonlattice (i.e., surface, coatings, segregation, secondary phase etc.) aluminum coordination and provide information that helps discern its effect in the lattice. In the present study, we use NMR to gain new insights into transition metal (TM)-O-Al coordination and evolution of lattice aluminum sites upon cycling. With the aid of first-principles DFT calculations, we show direct evidence of lattice Al sites, nonpreferential Ni/Co-O-Al ordering in NCA, and the lack of bulk lattice aluminum in aluminum-"doped" NMC. Aluminum coordination of the paramagnetic (lattice) and diamagnetic (nonlattice) nature is investigated for Al-doped NMC and NCA. For the latter, the evolution of the lattice site(s) upon cycling is also studied. A clear reordering of lattice aluminum environments due to nickel migration is observed in NCA upon extended cycling.

Atmospheric effects and societal consequences of regional scale nuclear conflicts and acts of individual nuclear terrorism

NASA Astrophysics Data System (ADS)

Toon, O. B.; Turco, R. P.; Robock, A.; Bardeen, C.; Oman, L.; Stenchikov, G. L.

2006-11-01

We assess the potential damage and smoke production associated with the detonation of small nuclear weapons in modern megacities. While the number of nuclear warheads in the world has fallen by about a factor of three since its peak in 1986, the number of nuclear weapons states is increasing and the potential exists for numerous regional nuclear arms races. Eight countries are known to have nuclear weapons, 2 are constructing them, and an additional 32 nations already have the fissile material needed to build substantial arsenals of low-yield (Hiroshima-sized) explosives. Population and economic activity worldwide are congregated to an increasing extent in megacities, which might be targeted in a nuclear conflict. Our analysis shows that, per kiloton of yield, low yield weapons can produce 100 times as many fatalities and 100 times as much smoke from fires as high-yield weapons, if they are targeted at city centers. A single "small'' nuclear detonation in an urban center could lead to more fatalities, in some cases by orders of magnitude, than have occurred in the major historical conflicts of many countries. We analyze the likely outcome of a regional nuclear exchange involving 100 15-kt explosions (less than 0.1% of the explosive yield of the current global nuclear arsenal). We find that such an exchange could produce direct fatalities comparable to all of those worldwide in World War II, or to those once estimated for a "counterforce'' nuclear war between the superpowers. Megacities exposed to atmospheric fallout of long-lived radionuclides would likely be abandoned indefinitely, with severe national and international implications. Our analysis shows that smoke from urban firestorms in a regional war would rise into the upper troposphere due to pyro-convection. Robock et al. (2006) show that the smoke would subsequently rise deep into the stratosphere due to atmospheric heating, and then might induce significant climatic anomalies on global scales.We also

Neutrino Opacity in High Density Nuclear Matter

DOE Office of Scientific and Technical Information (OSTI.GOV)

Santos, Sergio M. dos; Razeira, Moises; Vasconcellos, Cesar A.Z.

2004-12-02

We estimate the contribution of the nucleon weak magnetism on the neutrino absorption mean free path inside high density nuclear matter. In the mean field approach, three different ingredients are taken into account: (a) a relativistic generalization of the approach developed by Sanjay et al.; (b) the inclusion of the nucleon weak-magnetism (c) and the pseudo-scalar interaction involving the nucleons. Our main result shows that the neutrino absorption mean free path is three times the corresponding result obtained by those authors.

High-efficiency optical pumping of nuclear polarization in a GaAs quantum well

NASA Astrophysics Data System (ADS)

Mocek, R. W.; Korenev, V. L.; Bayer, M.; Kotur, M.; Dzhioev, R. I.; Tolmachev, D. O.; Cascio, G.; Kavokin, K. V.; Suter, D.

2017-11-01

The dynamic polarization of nuclear spins by photoexcited electrons is studied in a high quality GaAs/AlGaAs quantum well. We find a surprisingly high efficiency of the spin transfer from the electrons to the nuclei as reflected by a maximum nuclear field of 0.9 T in a tilted external magnetic field of 1 T strength only. This high efficiency is due to a low leakage of spin out of the polarized nuclear system, because mechanisms of spin relaxation other than the hyperfine interaction are strongly suppressed, leading to a long nuclear relaxation time of up to 1000 s. A key ingredient to that end is the low impurity concentration inside the heterostructure, while the electrostatic potential from charged impurities in the surrounding barriers becomes screened through illumination by which the spin relaxation time is increased compared to keeping the system in the dark. This finding indicates a strategy for obtaining high nuclear spin polarization as required for long-lasting carrier spin coherence.

A mathematical model for the release of noble gas and Cs from porous nuclear fuel based on VEGA 1&2 experiments

NASA Astrophysics Data System (ADS)

Simones, M. P.; Reinig, M. L.; Loyalka, S. K.

2014-05-01

Release of fission products from nuclear fuel in accidents is an issue of major concern in nuclear reactor safety, and there is considerable room for development of improved models, supported by experiments, as one needs to understand and elucidate role of various phenomena and parameters. The VEGA (Verification Experiments of radionuclides Gas/Aerosol release) program on several irradiated nuclear fuels investigated the release rates of radionuclides and results demonstrated that the release rates of radionuclides from all nuclear fuels tested decreased with increasing external gas pressure surrounding the fuel. Hidaka et al. (2004-2011) accounted for this pressure effect by developing a 2-stage diffusion model describing the transport of radionuclides in porous nuclear fuel. We have extended this 2-stage diffusion model to account for mutual binary gas diffusion in the open pores as well as to introduce the appropriate parameters to cover the slip flow regime (0.01 ⩽ Kn ⩽ 0.1). While we have directed our numerical efforts toward the simulation of the VEGA experiments and assessments of differences from the results of Hidaka et al., the model and the techniques reported here are of larger interest as these would aid in modeling of diffusion in general (e.g. in graphite and other nuclear materials of interest).

Probing Complexity using the LCLS and the ALS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Berrah, Nora

The goal of our research program is to investigate fundamental interactions between photons and molecular/nano-systems to advance our quantitative understanding of electron correlations, charge transfer and many body phenomena. Our research projects focus on probing, on a femtosecond time-scale, multi-electron interactions and tracing nuclear motion in order to understand, and ultimately control energy flow and charge transfer processes from electromagnetic radiation to matter. The experiments will be carried out with state of the art instrumentation built by the P.I. team with funds from a DoE "Single Investigator and Small Group Research" (SISGR) grant. The research projects carried out the pastmore » three years consisted of first experiments using the linac coherent light source (LCLS) x-ray free electron laser (FEL) facility at the SLAC National Laboratory, as well as the study of correlated processes in select anions using the ALS. A report for the past cycle is described in section II. These studies have paved the way for our renewal application for the next three years. Our research interests for the next three years extend our past and present research by carrying out time-resolved measurements described in section III. They will consist of: a) The study of molecular dynamics that happen on ultrafast time scales, using pump-probe schemes and the study of non-linear physics in the x-ray regime via multi-photon absorption from the LCLS. This will be achieved by measuring and examining both electronic and nuclear dynamics subsequent to the interaction of molecules and nano-systems with LCLS pulses of various wavelength, intensity and pulse duration as described in section III.A. b) The study of molecular dynamics and correlated processes via absorption of vuv-soft x-rays from the Advanced Light Source (ALS) at Lawrence Berkeley Laboratory to provide single-photon ionization baseline results for LCLS studies. In addition, we will study the photodetachment of

Support of the Iraq nuclear facility dismantlement and disposal program

DOE Office of Scientific and Technical Information (OSTI.GOV)

Coates, Roger; Cochran, John; Danneels, Jeff

2007-07-01

Available in abstract form only. Full text of publication follows: Iraq's former nuclear facilities contain large quantities of radioactive materials and radioactive waste. The Iraq Nuclear Facility Dismantlement and Disposal Program (the Iraq NDs Program) is a new program to decontaminate and permanently dispose of radioactive wastes in Iraq. The NDs Program is led by the Government of Iraq, under International Atomic Energy Agency (IAEA) auspices, with guidance and assistance from a number of countries. The U.S. participants include Texas Tech University and Sandia National Laboratories. A number of activities are ongoing under the broad umbrella of the Iraq NDsmore » Program: drafting a new nuclear law that will provide the legal basis for the cleanup and disposal activities; assembly and analysis of existing data; characterization of soil contamination; bringing Iraqi scientists to the world's largest symposium on radioactive waste management; touring U.S. government and private sector operating radwaste disposal facilities in the U.S., and hosting a planning workshop on the characterization and cleanup of the Al-Tuwaitha Nuclear Facility. (authors)« less

27Al MQMAS of the δ-Al 13-Keggin

DOE PAGES

Pilgrim, C. D.; Callahan, J. R.; Colla, C. A.; ...

2017-01-20

Here, one-dimensional 27Al, 23Na Magic-Angle-Spinning (MAS) NMR and 27Al Multiple-Quantum Magic-Angle-Spinning NMR (MQMAS) measurements are reported for the δ-isomer of the Al 13 Keggin structure at high spinning speed and 14.1 T field. Values for the CQ and η parameters are on the same scale as those seen in other isomers of the Al 13 structure. Density functional theory (DFT) calculations are performed for comparison to the experimental fits using the B3PW91/6-31+G* and PBE0/6-31+G* levels of theory, with the Polarizable Continuum Model (PCM).

Pressure induced coordination change of Al in silicate melts from Al K edge XANES of high pressure NaAlSi2O6-NaAlSi3O8 glasses

NASA Astrophysics Data System (ADS)

Li, Dien; Secco, R. A.; Bancroft, G. M.; Fleet, M. E.

Aluminum K-edge XANES spectra of high pressure and high temperature (4.4 GPa and 1575°C) glasses along the NaAlSi2O6 (Jd)-NaAlSi3O8 (Ab) join are reported using synchrotron radiation, and shown to provide direct experimental evidence for the pressure-induced coordination change of Al. Five- and six-fold coordinated Al (5Al and 6Al), characterized by Al K-edge positions at 1567.8 and 1568.7 eV, respectively, first appear in glass of composition Jd60Ab40 and increase in proportion progressively with increasing Jd content. The end-member jadeite glass contains about 6% of each of 5Al and 6Al. The present direct measurements confirm literature suggestions for the important role of Al in controlling viscosity and diffusion in mantle melts.

Assessing behavioural changes in ALS: cross-validation of ALS-specific measures.

PubMed

Pinto-Grau, Marta; Costello, Emmet; O'Connor, Sarah; Elamin, Marwa; Burke, Tom; Heverin, Mark; Pender, Niall; Hardiman, Orla

2017-07-01

The Beaumont Behavioural Inventory (BBI) is a behavioural proxy report for the assessment of behavioural changes in ALS. This tool has been validated against the FrSBe, a non-ALS-specific behavioural assessment, and further comparison of the BBI against a disease-specific tool was considered. This study cross-validates the BBI against the ALS-FTD-Q. Sixty ALS patients, 8% also meeting criteria for FTD, were recruited. All patients were evaluated using the BBI and the ALS-FTD-Q, completed by a carer. Correlational analysis was performed to assess construct validity. Precision, sensitivity, specificity, and overall accuracy of the BBI when compared to the ALS-FTD-Q, were obtained. The mean score of the whole sample on the BBI was 11.45 ± 13.06. ALS-FTD patients scored significantly higher than non-demented ALS patients (31.6 ± 14.64, 9.62 ± 11.38; p < 0.0001). A significant large positive correlation between the BBI and the ALS-FTD-Q was observed (r = 0.807, p < 0.0001), and no significant correlations between the BBI and other clinical/demographic characteristics indicate good convergent and discriminant validity, respectively. 72% of overall concordance was observed. Precision, sensitivity, and specificity for the classification of severely impaired patients were adequate. However, lower concordance in the classification of mild behavioural changes was observed, with higher sensitivity using the BBI, most likely secondary to BBI items which endorsed behavioural aspects not measured by the ALS-FTD-Q. Good construct validity has been further confirmed when the BBI is compared to an ALS-specific tool. Furthermore, the BBI is a more comprehensive behavioural assessment for ALS, as it measures the whole behavioural spectrum in this condition.

Doping and compensation in Al-rich AlGaN grown on single crystal AlN and sapphire by MOCVD

NASA Astrophysics Data System (ADS)

Bryan, Isaac; Bryan, Zachary; Washiyama, Shun; Reddy, Pramod; Gaddy, Benjamin; Sarkar, Biplab; Breckenridge, M. Hayden; Guo, Qiang; Bobea, Milena; Tweedie, James; Mita, Seiji; Irving, Douglas; Collazo, Ramon; Sitar, Zlatko

2018-02-01

In order to understand the influence of dislocations on doping and compensation in Al-rich AlGaN, thin films were grown by metal organic chemical vapor deposition (MOCVD) on different templates on sapphire and low dislocation density single crystalline AlN. AlGaN grown on AlN exhibited the highest conductivity, carrier concentration, and mobility for any doping concentration due to low threading dislocation related compensation and reduced self-compensation. The onset of self-compensation, i.e., the "knee behavior" in conductivity, was found to depend only on the chemical potential of silicon, strongly indicating the cation vacancy complex with Si as the source of self-compensation. However, the magnitude of self-compensation was found to increase with an increase in dislocation density, and consequently, AlGaN grown on AlN substrates demonstrated higher conductivity over the entire doping range.

Low-Lying Electronic States of AlZn Calculated by MRCI+Q Method

NASA Astrophysics Data System (ADS)

Zhang, Shudong; Wang, Mingxu; Wang, Zifan; Hu, Kun; Dong, Jingping

2017-07-01

Some low-lying electronic states of AlZn have been studied by the ab initio calculation method of multireference configuration interaction (MRCI). The complete potential energy curves (PECs) of the three lowest doublet states (X2Π, A2Σ+, and B2Π) and the two lowest quartet states (a4Σ- and b4Π) are computed in the range of R = 0.1-0.9 nm and these states are correlated to three dissociation limits, X2Π and A2Σ+ to Zn(4s2,1S) + Al(3s23p1,2P), a4Σ- and b4Π to Zn(4s2,1S) + Al(3s13p2,4P), and B2Π to Zn(4s14p1,3P) + Al(3s23p1,2P). The calculated PECs indicate that the A2Σ+ state has a very shallow potential well and the other states show significant binding-state characteristics. The equilibrium internuclear distances Re, dissociation energies De, and term energies Te for the electronic excited states were obtained. All the possible vibrational levels, rotational constants, and spectral constants for the four bound states were computed by solving the radial Schrödinger equation of nuclear motion with the Level8.0 program provided by Le Roy.

Microstructure of the irradiated U 3Si 2/Al silicide dispersion fuel

NASA Astrophysics Data System (ADS)

Gan, J.; Keiser, D. D.; Miller, B. D.; Jue, J.-F.; Robinson, A. B.; Madden, J. W.; Medvedev, P. G.; Wachs, D. M.

2011-12-01

The silicide dispersion fuel of U 3Si 2/Al is recognized as the best performance fuel for many nuclear research and test reactors with up to 4.8 gU/cm 3 fuel loading. An irradiated U 3Si 2/Al dispersion fuel ( 235U ˜ 75%) from the high-flux side of a fuel plate (U0R040) from the Reduced Enrichment for Research and Test Reactors (RERTR)-8 test was characterized using transmission electron microscopy (TEM). The fuel was irradiated in the Advanced Test Reactor (ATR) for 105 days. The average irradiation temperature and fission density of the U 3Si 2 fuel particles for the TEM sample are estimated to be approximately 110 °C and 5.4 × 10 27 f/m 3. The characterization was performed using a 200-kV TEM. The U/Si ratio for the fuel particle and (Si + Al)/U for the fuel-matrix-interaction layer are approximately 1.1 and 4-10, respectively. The estimated average diameter, number density and volume fraction for small bubbles (<1 μm) in the fuel particle are ˜94 nm, 1.05 × 10 20 m -3 and ˜11%, respectively. The results and their implication on the performance of the U 3Si 2/Al silicide dispersion fuel are discussed.

The Existence of a Designer Al=Al Double Bond in the LiAl2 H4- Cluster Formed by Electronic Transmutation.

PubMed

Lundell, Katie A; Zhang, Xinxing; Boldyrev, Alexander I; Bowen, Kit H

2017-12-22

The Al=Al double bond is elusive in chemistry. Herein we report the results obtained via combined photoelectron spectroscopy and ab initio studies of the LiAl 2 H 4 - cluster that confirm the formation of a conventional Al=Al double bond. Comprehensive searches for the most stable structures of the LiAl 2 H 4 - cluster have shown that the global minimum isomer I possesses a geometric structure which resembles that of Si 2 H 4 , demonstrating a successful example of the transmutation of Al atoms into Si atoms by electron donation. Theoretical simulations of the photoelectron spectrum discovered the coexistence of two isomers in the ion beam, including the one with the Al=Al double bond. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Lou Gehrig's Disease (ALS)

MedlinePlus

... for Educators Search English Español Lou Gehrig's Disease (ALS) KidsHealth / For Kids / Lou Gehrig's Disease (ALS) What's ... with ALS in the 1930s. What Happens in ALS? ALS damages motor neurons in the brain and ...

Adhesion layer for etching of tracks in nuclear trackable materials

DOEpatents

Morse, Jeffrey D.; Contolini, Robert J.

2001-01-01

A method for forming nuclear tracks having a width on the order of 100-200 nm in nuclear trackable materials, such as polycarbonate (LEXAN) without causing delamination of the LEXAN. The method utilizes an adhesion film having a inert oxide which allows the track to be sufficiently widened to >200 nm without delamination of the nuclear trackable materials. The adhesion film may be composed of a metal such as Cr, Ni, Au, Pt, or Ti, or composed of a dielectric having a stable surface, such as silicon dioxide (SiO.sub.2), silicon nitride (SiN.sub.x), and aluminum oxide (AlO). The adhesion film can either be deposited on top of the gate metal layer, or if the properties of the adhesion film are adequate, it can be used as the gate layer. Deposition of the adhesion film is achieved by standard techniques, such as sputtering or evaporation.

What Students Think About (Nuclear) Radiation - Before and After Fukushima

NASA Astrophysics Data System (ADS)

Neumann, S.

2014-06-01

Preparing successful science lessons is very demanding. One important aspect a teacher has to consider is the students' previous knowledge about the specific topic. This is why research about students' preconceptions has been, and continues to be, a major field in science education research. Following a constructivistic approach [R. Duit et al., International handbook of research on conceptual change, p. 629 (2008)], helping students learn is only possible if teachers know about students' ideas beforehand. Studies about students' conceptions regarding the major topics in physics education (e.g. mechanics, electrodynamics, optics, thermodynamics), are numerous and well-documented. The topic radiation, however, has seen very little empirical research about students' ideas and misconceptions. Some research was conducted after the events of Chernobyl [P. Lijnse et al., International Journal of Science Education 12, 67 (1990); B. Verplanken, Environment and Behavior 21, 7 (1989)] and provided interesting insight into some of the students' preconceptions about radiation. In order to contribute empirical findings to this field of research, our workgroup has been investigating the conceptions students have about the topic radiation for several years [S. Neumann et al., Journal of Science Education and Technology 21, 826 (2012)]. We used children's drawings and conducted short follow-up interviews with students (9 - 12 years old) and more detailed interviews with 15-year-old students. Both studies were originally done before the events in Fukushima and replicated a year later. We not only asked students about their general associations and emotions regarding the term radiation, but also examined the students' risk perceptions of different types of radiation. Through the use of open-ended questions we were able to examine students' conceptions about different types of radiation (including nuclear) that could be a hindrance to student learning. Our results show that students

Characterization of N-polar AlN in GaN/AlN/(Al,Ga)N heterostructures grown by metal-organic chemical vapor deposition

NASA Astrophysics Data System (ADS)

Li, Haoran; Mazumder, Baishakhi; Bonef, Bastien; Keller, Stacia; Wienecke, Steven; Speck, James S.; Denbaars, Steven P.; Mishra, Umesh K.

2017-11-01

In GaN/(Al,Ga)N high-electron-mobility transistors (HEMT), AlN interlayer between GaN channel and AlGaN barrier suppresses alloy scattering and significantly improves the electron mobility of the two-dimensional electron gas. While high concentrations of gallium were previously observed in Al-polar AlN interlayers grown by metal-organic chemical vapor deposition, the N-polar AlN (Al x Ga1-x N) films examined by atom probe tomography in this study exhibited aluminum compositions (x) equal to or higher than 95% over a wide range of growth conditions. The also investigated AlN interlayer in a N-polar GaN/AlN/AlGaN/ S.I. GaN HEMT structure possessed a similarly high x content.

Pure AlN layers in metal-polar AlGaN/AlN/GaN and AlN/GaN heterostructures grown by low-temperature ammonia-based molecular beam epitaxy

NASA Astrophysics Data System (ADS)

Kaun, Stephen W.; Mazumder, Baishakhi; Fireman, Micha N.; Kyle, Erin C. H.; Mishra, Umesh K.; Speck, James S.

2015-05-01

When grown at a high temperature (820 °C) by ammonia-based molecular beam epitaxy (NH3-MBE), the AlN layers of metal-polar AlGaN/AlN/GaN heterostructures had a high GaN mole fraction (∼0.15), as identified by atom probe tomography in a previous study (Mazumder et al 2013 Appl. Phys. Lett. 102 111603). In the study presented here, growth at low temperature (<740 °C) by NH3-MBE yielded metal-polar AlN layers that were essentially pure at the alloy level. The improved purity of the AlN layers grown at low temperature was correlated to a dramatic increase in the sheet density of the two-dimensional electron gas (2DEG) at the AlN/GaN heterointerface. Through application of an In surfactant, metal-polar AlN(3.5 nm)/GaN and AlGaN/AlN(2.5 nm)/GaN heterostructures grown at low temperature yielded low 2DEG sheet resistances of 177 and 285 Ω/□, respectively.

Interdiffusion in U 3Si-Al, U 3Si 2-Al, and USi-Al dispersion fuels during irradiation

NASA Astrophysics Data System (ADS)

Kim, Yeon Soo; Hofman, Gerard L.

2011-03-01

Uranium-silicide compound fuel dispersion in an Al matrix is used in research and test reactors worldwide. Interaction layer (IL) growth between fuel particles and the matrix is one of performance issues. The interaction layer growth data for U 3Si, U 3Si 2 and USi dispersions in Al were obtained from both out-of-pile and in-pile tests. The IL is dominantly U(AlSi) 3 from out-of-pile tests, but its (Al + Si)/U ratio from in-pile tests is higher than the out-of-pile data, because of amorphous behavior of the ILs. IL growth correlations were developed for U 3Si-Al and U 3Si 2-Al. The IL growth rates were dependent on the U/Si ratio of the fuel compounds. During irradiation, however, the IL growth rates did not decrease with the decreasing U/Si ratio by fission. It is reasoned that transition metal fission products in the IL compensate the loss of U atoms by providing chemical potential for Al diffusion and volume expansion by solid swelling and gas bubble swelling. The addition of Mo in U 3Si 2 reduces the IL growth rate, which is similar to that of UMo alloy dispersion in a silicon-added Al matrix.

β decay of proton-rich nucleus Al23 and astrophysical consequences

NASA Astrophysics Data System (ADS)

Iacob, V. E.; Zhai, Y.; Al-Abdullah, T.; Fu, C.; Hardy, J. C.; Nica, N.; Park, H. I.; Tabacaru, G.; Trache, L.; Tribble, R. E.

2006-10-01

We present the first study of the β decay of Al23 undertaken with pure samples. The study was motivated by nuclear astrophysics questions. Pure samples of Al23 were obtained from the momentum achromat recoil separator (MARS) of Texas A&M University, collected on a fast tape-transport system, and moved to a shielded location where β and β-γ coincidence measurements were made. We deduced β branching ratios and log ft values for transitions to states in Mg23, and from them determined unambiguously the spin and parity of the Al23 ground state to be Jπ=5/2+. We discuss how this excludes the large increases in the radiative proton capture cross section for the reaction Mg22(p,γ)Al23 at astrophysical energies, which were implied by claims that the spin and parity is Jπ=1/2+. The log ft for the Fermi transition to its isobaric analog state (IAS) in Mg23 is also determined for the first time. This IAS and a state 16 keV below it are observed, well separated in the same experiment for the first time. We can now solve a number of inconsistencies in the literature, exclude strong isospin mixing claimed before, and obtain a new determination of the resonance strength. Both states are resonances in the Na22(p,γ)Mg23 reaction at energies important in novae. The reactions Mg22(p,γ)Al23 and Na22(p,γ)Mg23 have both been suggested as possible candidates for diverting some of the flux in oxygen-neon novae explosions from the A=22 into the A=23 mass chain.

ALS - resources

MedlinePlus

Resources - ALS ... The following organizations are good resources for information on amyotrophic lateral sclerosis : Muscular Dystrophy Association -- www.mda.org/disease/amyotrophic-lateral-sclerosis National Amyotrophic Lateral Sclerosis (ALS) ...

Study of the Al m 26 ( d , p ) Al 27 Reaction and the Influence of the Al 26 0 + Isomer on the Destruction of Al 26 in the Galaxy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Almaraz-Calderon, S.; Rehm, K. E.; Gerken, N.

The existence of 26Al (t 1/2 = 7.17 × 10 5 yr) in the interstellar medium provides a direct confirmation of ongoing nucleosynthesis in the Galaxy. The presence of a low-lying 0 + isomer ( 26Al m), however, severely complicates the astrophysical calculations. Here we present for the first time a study of the 26Al m (d, p) 27 Al reaction using an isomeric 26Al beam. The selectivity of this reaction allowed the study of ℓ = 0 transfers to T = 1/2, and T = 3/2 states in 27Al . Mirror symmetry arguments were then used to constrain themore » 26Al m (p,γ) 27Si reaction rate and provide an experimentally determined upper limit of the rate for the destruction of isomeric 26Al via radiative proton capture reactions, which is expected to dominate the destruction path of 26Al m in asymptotic giant branch stars, classical novae, and core collapse supernovae.« less

Study of the Al m 26 ( d , p ) Al 27 Reaction and the Influence of the Al 26 0 + Isomer on the Destruction of Al 26 in the Galaxy

DOE PAGES

Almaraz-Calderon, S.; Rehm, K. E.; Gerken, N.; ...

2017-08-17

The existence of 26Al (t 1/2 = 7.17 × 10 5 yr) in the interstellar medium provides a direct confirmation of ongoing nucleosynthesis in the Galaxy. The presence of a low-lying 0 + isomer ( 26Al m), however, severely complicates the astrophysical calculations. Here we present for the first time a study of the 26Al m (d, p) 27 Al reaction using an isomeric 26Al beam. The selectivity of this reaction allowed the study of ℓ = 0 transfers to T = 1/2, and T = 3/2 states in 27Al . Mirror symmetry arguments were then used to constrain themore » 26Al m (p,γ) 27Si reaction rate and provide an experimentally determined upper limit of the rate for the destruction of isomeric 26Al via radiative proton capture reactions, which is expected to dominate the destruction path of 26Al m in asymptotic giant branch stars, classical novae, and core collapse supernovae.« less

Study of the ^{26}Al^{m}(d,p)^{27}Al Reaction and the Influence of the ^{26}Al 0^{+} Isomer on the Destruction of ^{26}Al in the Galaxy.

PubMed

Almaraz-Calderon, S; Rehm, K E; Gerken, N; Avila, M L; Kay, B P; Talwar, R; Ayangeakaa, A D; Bottoni, S; Chen, A A; Deibel, C M; Dickerson, C; Hanselman, K; Hoffman, C R; Jiang, C L; Kuvin, S A; Nusair, O; Pardo, R C; Santiago-Gonzalez, D; Sethi, J; Ugalde, C

2017-08-18

The existence of ^{26}Al (t_{1/2}=7.17×10^{5}  yr) in the interstellar medium provides a direct confirmation of ongoing nucleosynthesis in the Galaxy. The presence of a low-lying 0^{+} isomer (^{26}Al^{m}), however, severely complicates the astrophysical calculations. We present for the first time a study of the ^{26}Al^{m}(d,p)^{27}Al reaction using an isomeric ^{26}Al beam. The selectivity of this reaction allowed the study of ℓ=0 transfers to T=1/2, and T=3/2 states in ^{27}Al. Mirror symmetry arguments were then used to constrain the ^{26}Al^{m}(p,γ)^{27}Si reaction rate and provide an experimentally determined upper limit of the rate for the destruction of isomeric ^{26}Al via radiative proton capture reactions, which is expected to dominate the destruction path of ^{26}Al^{m} in asymptotic giant branch stars, classical novae, and core collapse supernovae.

Reduced electron back-injection in Al2O3/AlOx/Al2O3/graphene charge-trap memory devices

NASA Astrophysics Data System (ADS)

Lee, Sejoon; Song, Emil B.; Min Kim, Sung; Lee, Youngmin; Seo, David H.; Seo, Sunae; Wang, Kang L.

2012-12-01

A graphene charge-trap memory is devised using a single-layer graphene channel with an Al2O3/AlOx/Al2O3 oxide stack, where the ion-bombarded AlOx layer is intentionally added to create an abundance of charge-trap sites. The low dielectric constant of AlOx compared to Al2O3 reduces the potential drop in the control oxide Al2O3 and suppresses the electron back-injection from the gate to the charge-storage layer, allowing the memory window of the device to be further extended. This shows that the usage of a lower dielectric constant in the charge-storage layer compared to that of the control oxide layer improves the memory performance for graphene charge-trap memories.

Fundamental Study of Nuclear Pumped Laser Plasmas.

DTIC Science & Technology

1980-12-23

PUMPED DYE LASER PMT PUMPING/ GAS HAND- LING SYSTEM ANODE SIGNAL TO SCREEN ROOM FIGURE 13 EXPERIMENTAL APPARATUS FROM ANODE OF PMT SCREEN ROOM...and G.A. Zdasiuk, " Laser Induced Collisional and Radiative Energy Transfer’, Proceedings of Laser Spectroscopy IV, June 1979. W. R. Green, M.D. Wright...AD-A130 988 FUNDAMENTAL STUDY 0F NUCLEAR PUMPED LASER PLASMAS(U) 1/ MIAMI UNIV OXFORD UHDi EPT OF PHYSIS Cs W DOWNES ET AL 23 DEC AS OASGAS 7A C OSAN

77 FR 73732 - In the Matter of Amendment of the Designation of al-Qa'ida in Iraq, aka Jam'at al Tawhid wa'al...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-12-11

...'ida in Iraq, aka Jam'at al Tawhid wa'al-Jihad, aka The Monotheism and Jihad Group, aka The al-Zarqawi Network, aka al-Tawhid, aka Tanzim Qa`idat al-Jihad fi Bilad al-Rafidayn, aka The Organization of al-Jihad... Rivers, aka al-Qaida of Jihad Organization in the Land of the Two Rivers, aka al- Qaida Group of Jihad in...

Phenotypic and genotypic studies of ALS cases in ALS-SMA families.

PubMed

Corcia, Philippe; Vourc'h, Patrick; Blasco, Helene; Couratier, Philippe; Dangoumau, Audrey; Bellance, Remi; Desnuelle, Claude; Viader, Fausto; Pautot, Vivien; Millecamps, Stephanie; Bakkouche, Salah; Salachas, FranÇois; Andres, Christian R; Meininger, Vincent; Camu, William

2018-08-01

Amyotrophic lateral sclerosis (ALS) and spinal muscular atrophy (SMA) are the most frequent motor neuron disorders in adulthood and infancy, respectively. There is a growing literature supporting common pathophysiological patterns between those disorders. One important clinical issue for that is the co-occurrence of both diseases within a family. To collect families in which ALS and SMA patients co-exist and describe the phenotype and the genotype of ALS patients. Nine families with co-occurrence of SMA and ALS have been gathered over the last 15 years. Epidemiological, phenotype and genetic status were collected. Out of the nine families, six corresponded to the criteria of familial ALS (FALS). Clinical data were available for 11 patients out of the 15 ALS cases. Mean age of onset was 58.5 years, site of onset was lower limbs in nine cases (81.8%), median duration was 22 months. Four ALS patients carried a mutation: three mutations in SOD1 gene (G147N in two cases and one with E121G) and one repeat expansion in the C9ORF72 gene. Three patients had abnormal SMN1 copy numbers. While the high proportion of familial history of ALS cases in these ALS-SMA pedigrees could have suggested that these familial clusters of the two most frequent MND rely on a genetic background, we failed to exclude that this occurred by chance.

Distribution and size of lava shields on the Al Haruj al Aswad and the Al Haruj al Abyad Volcanic Systems, Central Libya

NASA Astrophysics Data System (ADS)

Elshaafi, Abdelsalam; Gudmundsson, Agust

2017-05-01

The Al Haruj Volcanic Province (AHVP) consists of two distinct volcanic systems. In the north is the system of Al Haruj al Aswad, covering an area of 34,200 km2, while in the south the system of Al Haruj al Abyad, covering an area of 7,850 km2. The systems have produced some 432 monogenetic volcanoes, primarily scoria (cinder) cones, lava shields, and maars. The density distribution of the volcanoes in each system, plotted as eruption points or sites, has a roughly elliptical surface expression, suggesting similar plan-view geometry of the magma sources, here suggested as deep-seated reservoirs. More specifically, the Al Haruj al Aswad magma reservoir has major and minor axes of 210 km and 119 km, respectively, and an area of 19,176 km2, the corresponding figures for the Haruj al Abyad reservoir being 108 km and 74 km, for the axes, and 6209 km2 for the area. We measured 55 lava shields on the AHVP. They are mostly restricted to the northern and southern parts of AHVP and date from late Miocene to (at least) the end of Pleistocene, while some may have been active into Holocene. In fact, although primarily monogenetic, some of the lava shields show evidence of (possibly Holocene) fissure eruptions in the summit parts. The early lava shields tend to be located at the edges of volcanic systems and with greater volumes than later (more central) shields. The average lava shield basal diameter is 4.5 km and height 63 m. There is strong linear correlation between lava shield volume and basal area, the coefficient of determination (R2) being about 0.75. When 22 Holocene Icelandic lava shields are added to the dataset, for comparison, the correlation between volume and basal area becomes R2 = 0.95. Numerical models suggest that the local stress fields favoured rupture and dyke injection at the margins of the source reservoirs during late Miocene - early Pliocene, in agreement with the distribution of the early, large-volume shields.

The Key Role of Nuclear-Spin Astrochemistry

NASA Astrophysics Data System (ADS)

Le Gal, Romane; Herbst, Eric; Xie, Changjian; Guo, Hua; Talbi, Dahbia; Muller, Sebastien; Persson, Carina

2017-06-01

Thanks to the new spectroscopic windows opened by the recent generation of telescopes, a large number of molecular lines have been detected. In particular, nuclear-spin astrochemistry has gained interest owing to numerous ortho-to-para ratio (OPR) measurements for species including H_3^+, CH_2, C_3H_2, H_2O, NH_3, NH_2, H_2S, H_2CS, H_2O^+ and H_2Cl^+. Any multi-hydrogenated species can indeed present different spin configurations, if some of their hydrogen nuclei are identical, and the species thus exist in distinguishable forms, such as ortho and para. In thermal equilibrium, OPRs are only functions of the temperature and since spontaneous conversion between ortho and para states is extremely slow in comparison with typical molecular cloud lifetimes, OPRs were commonly believed to reflect a ``formation temperature''. However, observed OPRs are not always consistent with their thermal equilibrium values, as for the NH_3 and NH_2 cases. It is thus crucial to understand how interstellar OPRs are formed to constrain the information such new probes can provide. This involves a comprehensive analysis of the processes governing the interstellar nuclear-spin chemistry, including the formation and possible conversions of the different spin symmetries both in the gas and solid phases. If well understood, OPRs might afford new powerful astrophysical diagnostics on the chemical and physical conditions of their environments, and in particular could trace their thermal history. In this context, observations of non-thermal values for the OPR of the radical NH_2 toward four high-mass star-forming regions, and a 3:1 value measured for the H_2Cl^+ OPR toward diffuse and denser gas, led us to develop detailed studies of the mechanisms involved in obtaining such OPRs with the aid of quasi-classical trajectory calculations. We will present these new promising results, improving our understanding of the interstellar medium. Persson et al. 2016, A&A, 586, A128, Neufeld et al. 2016, Ap

Exploring Localization in Nuclear Spin Chains

NASA Astrophysics Data System (ADS)

Wei, Ken Xuan; Ramanathan, Chandrasekhar; Cappellaro, Paola

2018-02-01

Characterizing out-of-equilibrium many-body dynamics is a complex but crucial task for quantum applications and understanding fundamental phenomena. A central question is the role of localization in quenching thermalization in many-body systems and whether such localization survives in the presence of interactions. Probing this question in real systems necessitates the development of an experimentally measurable metric that can distinguish between different types of localization. While it is known that the localized phase of interacting systems [many-body localization (MBL)] exhibits a long-time logarithmic growth in entanglement entropy that distinguishes it from the noninteracting case of Anderson localization (AL), entanglement entropy is difficult to measure experimentally. Here, we present a novel correlation metric, capable of distinguishing MBL from AL in high-temperature spin systems. We demonstrate the use of this metric to detect localization in a natural solid-state spin system using nuclear magnetic resonance (NMR). We engineer the natural Hamiltonian to controllably introduce disorder and interactions, and observe the emergence of localization. In particular, while our correlation metric saturates for AL, it slowly keeps increasing for MBL, demonstrating analogous features to entanglement entropy, as we show in simulations. Our results show that our NMR techniques, akin to measuring out-of-time correlations, are well suited for studying localization in spin systems.

Understanding the Relationship Between Structure and Thermophysical Properties of CaO-SiO2-MgO-Al2O3 Molten Slags

NASA Astrophysics Data System (ADS)

Sun, Yongqi; Wang, Hao; Zhang, Zuotai

2018-04-01

In the present work, the relationship between the microscopic structure and macroscopic thermophysical properties in a basic CaO-SiO2-MgO-Al2O3 quaternary system was identified using Fourier transformation infrared, Raman and 27Al magic angular spinning nuclear magnetic resonance (MAS-NMR) techniques. The Raman spectra quantitatively proved that with increasing Al2O3 content, the concentrations of the symmetric units of Q 0(Si) and Q 2(Si) decreased, while those of the asymmetric units of Q 1(Si) and Q 3(Si) increased; consequently, the degree of polymerization of the networks increased, which resulted in an increase in slag viscosity. The 27Al MAS-NMR spectra demonstrated that three structural units of Al atoms, namely, AlO4, AlO5, and AlO6, mainly existed in the networks. With increasing Al2O3 content, the concentration of AlO4 slightly decreased, while those of AlO5 and AlO6 increased; overall, Al2O3 acted as a network former in the present system. The increasing Al2O3 content led to additional AlO6 and Si-NBO-Ca-NBO-Al frameworks, which replaced Si-NBO-Ca-NBO-Si in the networks (NBO: non-bridging oxygen) and induced a change in the primarily precipitated crystalline phase from Ca2MgSi2O7 and Ca2Al2SiO7 to MgAlO4.

Formation of gamma'-Ni3Al via the Peritectoid Reaction: gamma plus beta (+Al2O3) equals gamma'(+Al2O3)

NASA Technical Reports Server (NTRS)

Copland, Evan

2008-01-01

The activities of Al and Ni were measured using multi-cell Knudsen effusion-cell mass spectrometry (multi-cell KEMS), over the composition range 8 - 32 at.%Al and temperature range T = 1400 - 1750 K in the Ni-Al-O system. These measurements establish that equilibrium solidification of gamma'-Ni3Al-containing alloys occurs by the eutectic reaction, L (+ Al2O3) = gamma + beta (+ Al2O3), at 1640 plus or minus 1 K and a liquid composition of 24.8 plus or minus 0.2 at.%Al (at an unknown oxygen content). The {gamma + beta + Al2O3} phase field is stable over the temperature range 1633 - 1640 K, and gamma'-Ni3Al forms via the peritectiod, gamma + beta (+ Al2O3) = gamma'(+ Al2O3), at 1633 plus or minus 1 K. This behavior is inconsistent with the current Ni-Al phase diagram and a new diagram is proposed. This new Ni-Al phase diagram explains a number of unusual steady state solidification structures reported previously and provides a much simpler reaction scheme in the vicinity of the gamma'-Ni3Al phase field.

Microtubule minus end motors kinesin-14 and dynein drive nuclear congression in parallel pathways.

PubMed

Scheffler, Kathleen; Minnes, Refael; Fraisier, Vincent; Paoletti, Anne; Tran, Phong T

2015-04-13

Microtubules (MTs) and associated motors play a central role in nuclear migration, which is crucial for diverse biological functions including cell division, polarity, and sexual reproduction. In this paper, we report a dual mechanism underlying nuclear congression during fission yeast karyogamy upon mating of haploid cells. Using microfluidic chambers for long-term imaging, we captured the precise timing of nuclear congression and identified two minus end-directed motors operating in parallel in this process. Kinesin-14 Klp2 associated with MTs may cross-link and slide antiparallel MTs emanating from the two nuclei, whereas dynein accumulating at spindle pole bodies (SPBs) may pull MTs nucleated from the opposite SPB. Klp2-dependent nuclear congression proceeds at constant speed, whereas dynein accumulation results in an increase of nuclear velocity over time. Surprisingly, the light intermediate chain Dli1, but not dynactin, is required for this previously unknown function of dynein. We conclude that efficient nuclear congression depends on the cooperation of two minus end-directed motors. © 2015 Scheffler et al.

Directional Solidification and Mechanical Properties of NiAl-NiAlTa Alloys

NASA Technical Reports Server (NTRS)

Johnson, D. R.; Chen, X. F.; Oliver, B. F.; Noebe, R. D.; Whittenberger, J. D.

1995-01-01

Directional solidification of eutectic alloys is a promising technique for producing in-situ composite materials exhibiting a balance of properties. Consequently, the microstructure, creep strength and fracture toughness of directionally solidified NiAl-NiAlTa alloys were investigated. Directional solidification was performed by containerless processing techniques to minimize alloy contamination. The eutectic composition was found to be NiAl-15.5 at% Ta and well-aligned microstructures were produced at this composition. A near-eutectic alloy of NiAl-14.5Ta was also investigated. Directional solidification of the near-eutectic composition resulted in microstructures consisting of NiAl dendrites surrounded by aligned eutectic regions. The off-eutectic alloy exhibited promising compressive creep strengths compared to other NiAl-based intermetallics, while preliminary testing indicated that the eutectic alloy was competitive with Ni-base single crystal superalloys. The room temperature toughness of these two-phase alloys was similar to that of polycrystalline NiAl even with the presence of the brittle Laves phase NiAlTa.

Response to Comment on 'Prevented Mortality and Greenhouse Gas Emissions from Historical and Projected Nuclear Power'

NASA Technical Reports Server (NTRS)

Kharecha, Pushker A.; Hansen, James

2013-01-01

Sovacool et al.'s analysis of our paper contains numerous errors, misinterpretations, and dubious assumptions. For instance, we make no presumption in our paper that nuclear power is the only major option to replace fossil fuels nor have we in the past, as evidenced by our other peer-reviewed publications. Furthermore, all of our results are based on complete fuel cycle analysis and are presented as mean values along with their ranges. Thus it is incorrect to claim that we single out the worst estimates for coal mortality. Contrary to Sovacool et al.'s assertions, our only bias is our belief that humanity's best chance of success for mitigating the daunting challenge of climate change is to utilize all available and proven means.

New insights on pressure, temperature, and chemical stability of CsAlSi5O12, a potential host for nuclear waste

NASA Astrophysics Data System (ADS)

Gatta, G. D.; Brundu, A.; Cappelletti, P.; Cerri, G.; de'Gennaro, B.; Farina, M.; Fumagalli, P.; Guaschino, L.; Lotti, P.; Mercurio, M.

2016-10-01

A Cs-bearing polyphase aggregate with composition (in wt%): 76(1)CsAlSi5O12 + 7(1)CsAlSi2O6 + 17(1)amorphous, was obtained from a clinoptilolite-rich epiclastic rock after a beneficiation process of the starting material (aimed to increase the fraction of zeolite to 90 wt%), cation exchange and then thermal treatment. CsAlSi5O12 is an open-framework compound with CAS topology; CsAlSi2O6 is a pollucite-like material with ANA topology. The thermal stability of this polyphase material was investigated by in situ high- T X-ray powder diffraction, the combined P- T effects by a series of runs with a single-stage piston cylinder apparatus, and its chemical stability following the "availability test" ("AVA test") protocol. A series of additional investigations were performed by WDS-electron microprobe analysis in order to describe the P- T-induced modification of the material texture, and to chemically characterize the starting material and the run products. The "AVA tests" of the polyphase aggregate show an extremely modest release of Cs+: 0.05 mg/g. In response to applied temperature and at room P, CsAlSi5O12 experiences an unquenchable and displacive Ama2-to- Amam phase transition at about 770 K, and the Amam polymorph is stable in its crystalline form up to 1600 K; a crystalline-to-amorphous phase transition occurs between 1600 and 1650 K. In response to the applied P = 0.5 GPa, the crystalline-to-amorphous transition of CsAlSi5O12 occurs between 1670 and 1770 K. This leads to a positive Clapeyron slope (i.e., d P/d T > 0) of the crystalline-to-amorphous transition. When the polyphase aggregate is subjected at P = 0.5 GPa and T > 1770 K, CsAlSi5O12 melts and only CsAlSi2O6 (pollucite-like; dominant) and Cs-rich glass (subordinate) are observed in the quenched sample. Based on its thermo-elastic behavior, P- T phase stability fields, and Cs+ retention capacity, CsAlSi5O12 is a possible candidate for use in the immobilization of radioactive isotopes of Cs, or as

Theory and X-ray Absorption Spectroscopy for Aluminum Coordination Complexes – Al K-Edge Studies of Charge and Bonding in (BDI)Al, (BDI)AlR2, and (BDI)AlX2 Complexes.

PubMed

Altman, Alison B; Pemmaraju, C D; Camp, Clément; Arnold, John; Minasian, Stefan G; Prendergast, David; Shuh, David K; Tyliszczak, Tolek

2015-08-19

Polarized aluminum K-edge X-ray absorption near edge structure (XANES) spectroscopy and first-principles calculations were used to probe electronic structure in a series of (BDI)Al, (BDI)AlX2, and (BDI)AlR2 coordination compounds (X = F, Cl, I; R = H, Me; BDI = 2,6-diisopropylphenyl-β-diketiminate). Spectral interpretations were guided by examination of the calculated transition energies and polarization-dependent oscillator strengths, which agreed well with the XANES spectroscopy measurements. Pre-edge features were assigned to transitions associated with the Al 3p orbitals involved in metal-ligand bonding. Qualitative trends in Al 1s core energy and valence orbital occupation were established through a systematic comparison of excited states derived from Al 3p orbitals with similar symmetries in a molecular orbital framework. These trends suggested that the higher transition energies observed for (BDI)AlX2 systems with more electronegative X(1-) ligands could be ascribed to a decrease in electron density around the aluminum atom, which causes an increase in the attractive potential of the Al nucleus and concomitant increase in the binding energy of the Al 1s core orbitals. For (BDI)Al and (BDI)AlH2 the experimental Al K-edge XANES spectra and spectra calculated using the eXcited electron and Core-Hole (XCH) approach had nearly identical energies for transitions to final state orbitals of similar composition and symmetry. These results implied that the charge distributions about the aluminum atoms in (BDI)Al and (BDI)AlH2 are similar relative to the (BDI)AlX2 and (BDI)AlMe2 compounds, despite having different formal oxidation states of +1 and +3, respectively. However, (BDI)Al was unique in that it exhibited a low-energy feature that was attributed to transitions into a low-lying p-orbital of b1 symmetry that is localized on Al and orthogonal to the (BDI)Al plane. The presence of this low-energy unoccupied molecular orbital on electron-rich (BDI)Al distinguishes

Development of Al2O3 fiber-reinforced Al2O3-based ceramics.

PubMed

Tanimoto, Yasuhiro; Nemoto, Kimiya

2004-09-01

The purpose of this study was to use a tape casting technique to develop an Al2O3 fiber-reinforced Al2O3-based ceramic material (Al2O3-fiber/Al2O3 composite) into a new type of dental ceramic. The Al2O3-based ceramic used a matrix consisting of 60 wt% Al2O3 powder and 40 wt% SiO2-B2O3 powder. The prepreg sheets of Al2O3-fiber/Al2O3 composite (in which uniaxially aligned Al2O3 fibers were infiltrated with the Al2O3-based matrix) were fabricated continuously using tape casting technique with a doctor blade system. Multilayer preforms of Al2O3-fiber/Al2O3 composite sheets were then sintered at a maximum temperature of 1000 degrees C under an atmospheric pressure in a furnace. The results showed that the shrinkage and bending properties of Al2O3-fiber/Al2O3 composite exceeded those of unreinforced Al2O3--hence demonstrating the positive effects of fiber reinforcement. In conclusion, the tape casting technique has been utilized to successfully develop a new type of dental ceramic material.

[Genealogy of the Books of Practica medicinae in Europe before the End of 18th Century: From the Origin to the Disappearance].

PubMed

Sakai, Tatsuo

2015-09-01

The Practica medicinae represented the books written in Europe before the end of 18th century that dealt with individual deseases. In total, 100 Practica books, written by 95 authors, were collected and divided into four periods from the early 11th to the end of 18th century. The first Practica book was written at the Salernitan medical school on the basis of ancient medical books in the basic style, dealing with regional deseases arranged in "a capite ad calcem" manner, as well as with the fevers. The basic style comprised a majority in the first period and decreased gradually, becoming a minority in the 3rd and 4th periods. Sennert's practica was the largest and it elaborated with precise construction. The additional categories, such as female, children, and surgical deseases increased in the later periods. Those written in non-basic style based on pathogenesis or in alphabetical order also increased in the later periods. The practica books changed slightly and gradually, indicating the essential consistency of the concepts of diseases in these periods.

Nuclear planetology: understanding planetary mantle and crust formation in the light of nuclear and particle physics

NASA Astrophysics Data System (ADS)

Roller, Goetz

2017-04-01

conceptual model constraining the evolution of a rocky planet like Earth or Mercury from a stellar precursor of the oldest population to a Fe-C BLD, shifting through different spectral classes in a HR diagram after massive decompression and tremendous energy losses. In the light of WD/BLD cosmochronology [1], solar system bodies like Earth, Mercury and Moon are regarded as captured interlopers from the Galactic bulge, Earth and Moon possibly representing remnants of an old binary system. Such a preliminary scenario is supported by similar ages obtained from WD's for the Galactic halo [1] and, independently, by means of 187Re-232Th-238U nuclear geochronometry [3, 4], together with recent observations extremely metal-poor stars from the cosmic dawn in the bulge of the Milky Way [8]. This might be further elucidated in the near future by Th/U cosmochronometry based upon a nuclear production ratio Th/U = 0.96 [9] and additionally by means of a newly developed nucleogeochronometric age dating method for stellar spectroscopy [9-11]. The model shall stimulate geochemical data interpretation from a different perspective, to constrain the evolution and differentiation of planetary or lunar crusts and mantles in general. [1] Fontaine et al. (2001), Public. Astron. Soc. of the Pacific 113, 409-435. [2] Roller (2015), Abstract T34B-0407, AGU Spring Meeting 2015. [3] Roller (2016), Goldschmidt Conf. Abstr. 26, 2642. [4] Roller (2015), Goldschmidt Conf. Abstr. 25, 2672. [5] Roller (2015), Geophys. Res. Abstr. 18, EGU2016-33. [6] Arevalo et al. (2010), Chem. Geol. 271, 70-85. [7] Roller (2015), Geophys. Res. Abstr. 17, EGU2015-2399. [8] Howes et al. (2015), Nature 527, 484-487. [9] Roller (2016), JPS Conf. Proc., Nuclei in the Cosmos (NIC XIV), Niigata, Japan, subm. (NICXIV-001); NICXIV Abstr. #1570244284. [10] Roller (2016), JPS Conf. Proc., Nuclei in the Cosmos (NIC XIV), Niigata, Japan, subm. (NICXIV-002); NICXIV Abstr. #1570244285. [11] Roller (2016), JPS Conf. Proc., Nuclei in the

Childhood cancers near German nuclear power stations: the ongoing debate.

PubMed

Fairlie, Ian

2009-01-01

In late 2007, the significant KiKK study (Kinderkrebs in der Umgebung von KernKraftwerken = Childhood Cancer in the Vicinity of Nuclear Power Plants) in Germany reported a 1.6-fold increase in all cancers and a 2.2-fold increase in leukaemias, among children living within 5 km of all German nuclear power stations. The KiKK study by Kaatsch et al. was extensively described in a recent edition of Medicine Conflict and Survival. It has triggered much discussion as to the cause(s) of these increased cancers. This article reports on recent developments on the KiKK study, including responses by German radiation agencies, and recent epidemiological studies near United Kingdom and French nuclear installations. It reflects the current debate and concludes with advice to policy-makers on radiation risks on the relative merits of the KiKK study. An accompanying article outlines a possible explanation for the increased cancers and makes recommendations for future research.

NiAl-base composite containing high volume fraction of AlN for advanced engines

NASA Technical Reports Server (NTRS)

Hebsur, Mohan (Inventor); Whittenbeger, John D. (Inventor); Lowell, Carl F. (Inventor)

1994-01-01

A particulate reinforced NiAl-AlN composite alloy has a NiAl matrix and greater than about 13 volume percent fine particles of AlN within the matrix. The particles preferably have a diameter from about 15 nanometers to about 50 nanometers. The particulate reinforced NiAl-AlN composite alloy may be prepared by cryomilling prealloyed NiAl in liquid nitrogen using grinding media having a diameter of from about 2 to 6 mm at an impeller speed of from about 450 RPM to about 800 RPM. The cryomilling may be done for a duration of from about 4 hours to about 20 hours to obtain a cryomilled powder. The cryomilled powder may be consolidated to form the particulate reinforced NiAl-AlN composite alloy. The particulate reinforced alloy can further include a toughening alloy. The toughening alloy may include NiCrAlY, FeCrAlY, and FeAl.

Molecular dynamics study of Al and Ni 3Al sputtering by Al clusters bombardment

NASA Astrophysics Data System (ADS)

Zhurkin, Eugeni E.; Kolesnikov, Anton S.

2002-06-01

The sputtering of Al and Ni 3Al (1 0 0) surfaces induced by impact of Al ions and Al N clusters ( N=2,4,6,9,13,55) with energies of 100 and 500 eV/atom is studied at atomic scale by means of classical molecular dynamics (MD). The MD code we used implements many-body tight binding potential splined to ZBL at short distances. Special attention has been paid to model dense cascades: we used quite big computation cells with lateral periodic and damped boundary conditions. In addition, long simulation times (10-25 ps) and representative statistics (up to 1000 runs per each case) were considered. The total sputtering yields, energy and time spectrums of sputtered particles, as well as preferential sputtering of compound target were analyzed, both in the linear and non-linear regimes. The significant "cluster enhancement" of sputtering yield was found for cluster sizes N⩾13. In parallel, we estimated collision cascade features depending on cluster size in order to interpret the nature of observed non-linear effects.

Homeopathy and acupuncture teaching at Faculdade de Medicina da Universidade de São Paulo: the undergraduates' attitudes.

PubMed

Teixeira, Marcus Zulian; Lin, Chin An; Martins, Milton de Arruda

2005-03-02

Homeopathy and acupuncture, although recognized as medical specializations in Brazil, are not taught in most medical schools. The objective was to evaluate undergraduate attitudes towards them following their inclusion as optional disciplines at Faculdade de Medicina da Universidade de São Paulo (FMUSP) in 2002. Questionnaire, at FMUSP. 484 students answered a self-administered questionnaire on these therapies, regarding their interest in learning, the teaching methods, their knowledge/experience (or that of someone close to them) and how it was acquired, the main indicators and general effectiveness of these therapies, and the possibilities for offering and integrating them within public healthcare units. Over 85% of the students considered that homeopathy and acupuncture should be included in curricula, as options (72%) or compulsorily (19%); 56% showed great interest in learning about them. Although 76% had little or no knowledge, 67% believed that these therapies had some effectiveness, and that chronic diseases (37%) or even chronic and acute diseases (29%) would be the main indicators for their use. Around 35% were receptive towards offering public primary care using both therapies, while 34% thought these treatments should also be available in hospitals and 60% believed they could be integrated with conventional medical practices. The medical students were interested in learning the principles of homeopathy and acupuncture, were able to observe and report on the effectiveness of these treatments and defended the use of these medical specializations within public healthcare.

What Students Think About (Nuclear) Radiation – Before and After Fukushima

DOE Office of Scientific and Technical Information (OSTI.GOV)

Neumann, S.

Preparing successful science lessons is very demanding. One important aspect a teacher has to consider is the students' previous knowledge about the specific topic. This is why research about students' preconceptions has been, and continues to be, a major field in science education research. Following a constructivistic approach [R. Duit et al., International handbook of research on conceptual change, p. 629 (2008)], helping students learn is only possible if teachers know about students' ideas beforehand. Studies about students' conceptions regarding the major topics in physics education (e.g. mechanics, electrodynamics, optics, thermodynamics), are numerous and well-documented. The topic radiation, however, hasmore » seen very little empirical research about students' ideas and misconceptions. Some research was conducted after the events of Chernobyl [P. Lijnse et al., International Journal of Science Education 12, 67 (1990); B. Verplanken, Environment and Behavior 21, 7 (1989)] and provided interesting insight into some of the students' preconceptions about radiation. In order to contribute empirical findings to this field of research, our workgroup has been investigating the conceptions students have about the topic radiation for several years [S. Neumann et al., Journal of Science Education and Technology 21, 826 (2012)]. We used children's drawings and conducted short follow-up interviews with students (9 – 12 years old) and more detailed interviews with 15-year-old students. Both studies were originally done before the events in Fukushima and replicated a year later. We not only asked students about their general associations and emotions regarding the term radiation, but also examined the students' risk perceptions of different types of radiation. Through the use of open-ended questions we were able to examine students' conceptions about different types of radiation (including nuclear) that could be a hindrance to student learning. Our results show that

Toxic PRn poly-dipeptides encoded by the C9orf72 repeat expansion block nuclear import and export.

PubMed

Shi, Kevin Y; Mori, Eiichiro; Nizami, Zehra F; Lin, Yi; Kato, Masato; Xiang, Siheng; Wu, Leeju C; Ding, Ming; Yu, Yonghao; Gall, Joseph G; McKnight, Steven L

2017-02-14

The toxic proline:arginine (PR n ) poly-dipeptide encoded by the (GGGGCC) n repeat expansion in the C9orf72 form of heritable amyotrophic lateral sclerosis (ALS) binds to the central channel of the nuclear pore and inhibits the movement of macromolecules into and out of the nucleus. The PR n poly-dipeptide binds to polymeric forms of the phenylalanine:glycine (FG) repeat domain, which is shared by several proteins of the nuclear pore complex, including those in the central channel. A method of chemical footprinting was used to characterize labile, cross-β polymers formed from the FG domain of the Nup54 protein. Mutations within the footprinted region of Nup54 polymers blocked both polymerization and binding by the PR n poly-dipeptide. The aliphatic alcohol 1,6-hexanediol melted FG domain polymers in vitro and reversed PR n -mediated enhancement of the nuclear pore permeability barrier. These data suggest that toxicity of the PR n poly-dipeptide results in part from its ability to lock the FG repeats of nuclear pore proteins in the polymerized state. Our study offers a mechanistic interpretation of PR n poly-dipeptide toxicity in the context of a prominent form of ALS.

Nb/Al-AlOx/Nb Edge Junctions for Distributed Mixers

NASA Astrophysics Data System (ADS)

Amos, R. S.; Lichtenberger, A. W.; Tong, C. E.; Blundell, R.; Pan, S.-K.; Kerr, A. R.

We have fabricated high quality Nb/Al-oxide/Al/Nb edge junctions using a Nb/SiO/sub 2/ bi-layer film as the base electrode, suitable for use as traveling wave mixers. An edge is cut in the bi-layer with an ion gun at a 45 degree angle using a photoresist mask. The wafer is then cleaned in-situ with a physical ion gun clean followed by the deposition of a thin Al (a1) film, which is then thermally oxidized, an optional second Al (a2) layer, and a Nb counter electrode. It was found that devices with an a2 layer resulted in superior electrical characteristics, though proximity effects increased strongly with a2 thickness. The counter electrode is defined with an SF/sub 6/+N/sub 2/ reactive ion etch, using the Al barrier layer as an etch stop. The Al barrier layer is then either removed with an Al wet etch to isolate the individual devices, or the devices are separated with an anodization process. Various ion gun cleaning conditions have been examined; in addition, both wet and plasma etch bi-layer edge surface pre-treatments were investigated. It was found that edge junctions with large widths (i.e., those more suitable for traveling wave mixers) typically benefited more from such treatments. Initial receiver results at 260 GHz have yielded a DSB noise temperature of 60 K.

Solid state nuclear magnetic resonance with magic-angle spinning and dynamic nuclear polarization below 25 K

PubMed Central

Thurber, Kent R.; Potapov, Alexey; Yau, Wai-Ming; Tycko, Robert

2012-01-01

We describe an apparatus for solid state nuclear magnetic resonance (NMR) with dynamic nuclear polarization (DNP) and magic-angle spinning (MAS) at 20–25 K and 9.4 Tesla. The MAS NMR probe uses helium to cool the sample space and nitrogen gas for MAS drive and bearings, as described earlier (Thurber et al., J. Magn. Reson. 2008) [1], but also includes a corrugated waveguide for transmission of microwaves from below the probe to the sample. With a 30 mW circularly polarized microwave source at 264 GHz, MAS at 6.8 kHz, and 21 K sample temperature, greater than 25-fold enhancements of cross-polarized 13C NMR signals are observed in spectra of frozen glycerol/water solutions containing the triradical dopant DOTOPA-TEMPO when microwaves are applied. As demonstrations, we present DNP-enhanced one-dimensional and two-dimensional 13C MAS NMR spectra of frozen solutions of uniformly 13C-labeled L-alanine and melittin, a 26-residue helical peptide that we have synthesized with four uniformly 13C-labeled amino acids. PMID:23238592

Photoelectrical, photophysical and photocatalytic properties of Al based MOFs: MIL-53(Al) and MIL-53-NH{sub 2}(Al)

DOE Office of Scientific and Technical Information (OSTI.GOV)

An, Yang; Li, Huiliang; Liu, Yuanyuan, E-mail: yyliu@sdu.edu.cn

Two Al based MOFs (MIL-53(Al) and MIL-53-NH{sub 2} (Al)) were synthesized, and their photoelectrical, photophysical and photocatalytic properties towards oxygen evolution from water were investigated. Different from the ligand to metal charge transfer process previously reported, we proposes a new photocatalytic mechanism based on electron tunneling according to the results of theoretical calculation, steady state and time resolved fluorescence spectra. The organic linkers absorb photons, giving rise to electrons and holes. Then, the photogenerated electrons tunnel through the AlO{sub 6}-octahedra, which not only inhibit the recombination of photogenerated charge carriers, but also is a key factor to the photocatalytic activitymore » of Al based MOFs. - Graphical abstract: The photoelectrical, photophysical and photocatalytic properties towards oxygen evolution from water of two Al based MOFs were investigated. A new photocatalytic mechanism was proposed based on electron tunneling according to the results of both theoretical calculation and steady state, time resolved fluorescence spectra. The electron tunneling process not only inhibit the recombination of photogenerated charge carriers, but also is a key factor to the photocatalytic activity of Al based MOFs.« less

Ethanol Sensor of CdO/Al2O3/CeO2 Obtained from Ce-DOPED Layered Double Hydroxides with High Response and Selectivity

NASA Astrophysics Data System (ADS)

Xu, Dongmei; Guan, Meiyu; Xu, Qinghong; Guo, Ying; Wang, Yao

2013-04-01

In this paper, Ce-doped CdAl layered double hydroxide (LDH) was first synthesized and the derivative CdO/Al2O3/CeO2 composite oxide was prepared by calcining Ce-doped CdAl LDH. The structure, morphology and chemical state of the Ce doped CdAl LDH and CdO/Al2O3/CeO2 were also investigated by X-ray diffraction (XRD), Fourier transform infrared (FT-IR), solid state nuclear magnetic resonance (SSNMR), scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS). The gas sensing properties of CdO/Al2O3/CeO2 to ethanol were further studied and compared with CdO/Al2O3 prepared from CdAl LDH, CeO2 powder as well as the calcined Ce salt. It turns out that CdO/Al2O3/CeO2 sensor shows best performance in ethanol response. Besides, CdO/Al2O3/CeO2 possesses short response/recovery time (12/72 s) as well as remarkable selectivity in ethanol sensing, which means composite oxides prepared from LDH are very promising in gas sensing application.

Oxidation of Al2O3 continuous fiber-reinforced/NiAl composites

NASA Technical Reports Server (NTRS)

Doychak, J.; Nesbitt, J. A.; Noebe, R. D.; Bowman, R. R.

1992-01-01

The 1200 C and 1300 C isothermal and cyclic oxidation behavior of Al2O3 continuous fiber-reinforced/NiAl composites were studied. Oxidation resulted in formation of Al2O3 external scales in a similar manner as scales formed on monolithic NiAl. The isothermal oxidation of an Al2O3/NiAl composite resulted in oxidation of the matrix along the fiber/matrix interface near the fiber ends. This oxide acted as a wedge between the fiber and the matrix, and, under cyclic oxidation conditions, led to further oxidation along the fiber lengths and eventual cracking of the composite. The oxidation behavior of composites in which the Al2O3 fibers were sputter coated with nickel prior to processing was much more severe. This was attributed to open channels around the fibers which formed during processing, most likely as a result of the diffusion of the nickel coating into the matrix.

Structure of oxides prepared by decomposition of layered double Mg–Al and Ni–Al hydroxides

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cherepanova, Svetlana V.; Novosibirsk State University, Novosibirsk; Leont’eva, Natalya N., E-mail: n_n_leonteva@list.ru

2015-05-15

Abstracts: Thermal decomposition of Mg–Al and Ni–Al layered double hydroxides LDH at temperatures lower than 800 °C leads to the formation of oxides with different structures. Mg–Al oxide has a very defective structure and consists of octahedral layers as in periclase MgO and mixed octahedral–tetrahedral layers as in spinel MgAl{sub 2}O{sub 4}. Mixed Ni–Al oxide has a sandwich-like structure, consisting of a core with Al-doped NiO-like structure and some surface layers with spinel NiAl{sub 2}O{sub 4} structure epitaxial connected with the core. Suggested models were verified by simulation of X-ray diffraction patterns using DIFFaX code, as well as HRTEM, IR-,more » UV-spectroscopies, and XPS. - Graphical abstract: In the Mg–Al layered double hydroxide Al{sup 3+} ions migrate into interlayers during decomposition. The Mg–Al oxide represents sequence of octahedral and octahedral–tetrahedral spinel layers with vacancies. The Ni–Al oxide has a sandwich-like structure with NiO-like core and surface spinel layers as a result of migration of Al{sup 3+} ions on the surface. The models explain the presence and absence of “memory effect” for the Mg–Al and Ni–Al oxides, respectively. - Highlights: • We study products of Mg(Ni)–Al LDH decomposition by calcination at 500(400)–800 °C. • In Mg–Al/Ni–Al LDH Al ions migrate into interlayers/on the surface during decomposition. • Mg–Al oxide represents sequence of periclase- and spinel-like layers with vacancies. • Ni–Al oxide has a sandwich-like structure with NiO-like core and surface spinel layers. • The models explain the presence/absence of “memory effect” for Mg–Al/Ni–Al oxides.« less

Permanent Disposal of Nuclear Waste in Salt

NASA Astrophysics Data System (ADS)

Hansen, F. D.

2016-12-01

Salt formations hold promise for eternal removal of nuclear waste from our biosphere. Germany and the United States have ample salt formations for this purpose, ranging from flat-bedded formations to geologically mature dome structures. Both nations are revisiting nuclear waste disposal options, accompanied by extensive collaboration on applied salt repository research, design, and operation. Salt formations provide isolation while geotechnical barriers reestablish impermeability after waste is placed in the geology. Between excavation and closure, physical, mechanical, thermal, chemical, and hydrological processes ensue. Salt response over a range of stress and temperature has been characterized for decades. Research practices employ refined test techniques and controls, which improve parameter assessment for features of the constitutive models. Extraordinary computational capabilities require exacting understanding of laboratory measurements and objective interpretation of modeling results. A repository for heat-generative nuclear waste provides an engineering challenge beyond common experience. Long-term evolution of the underground setting is precluded from direct observation or measurement. Therefore, analogues and modeling predictions are necessary to establish enduring safety functions. A strong case for granular salt reconsolidation and a focused research agenda support salt repository concepts that include safety-by-design. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000. Author: F. D. Hansen, Sandia National Laboratories

187Re - 187Os Nuclear Geochronometry: A New Dating Method Applied to Old Ores

NASA Astrophysics Data System (ADS)

Roller, Goetz

2015-04-01

very old rapid (r) neutron-capture process signatures from (at least) two different events. In this scenario, intermediate 187Os/186Osi ratios are due to mixing, resulting from the interaction of the two ancient components. Since there is a striking agreement between the nucleogeochronometric TPI ages and the conventional isochrone and mineral ages for the SC and SIC, respectively, nuclear geochronometry may offer an enormous potential for exploration purposes in mining industry, especially if additional geochemical and petrologic cross-correlations are taken into account. Furthermore, there might be now a new and promising opportunity to understand the link between magmatic ore forming processes and global geodynamics. [1] Burbidge et al. (1957) Revs. Mod. Phys. 29, 547 - 650. [2] Cameron (1957), CRL-41, Atomic Energy of Canada Limited, Chalk River, Ontario. [3] Hoyle et al. (1960) ApJ 132, 565 - 590. [4] Birck et al. (1994) EPSL 124, 139-148. [5] Roller (1997), PhD Thesis, RKP N+T, Munich. [6] Marcantonio et al. (1993), GCA 57, 4029 - 4037. [7] Walker et al. (1991) EPSL 105, 416 - 429.

Cooperation Among Nations: Understanding the Counter Nuclear Smuggling Network In Europe

DTIC Science & Technology

2016-06-01

Washington DC 20503. 1. AGENCY USE ONLY (Leave blank) 2. REPORT DATE June 2016 3. REPORT TYPE AND DATES COVERED Capstone project report 4. TITLE AND...fixed report date and subject to change with the dynamic international environment. The existence of the European Union (EU) complicates the...100 Bunn et al., “Preventing Nuclear Terrorism,” 4. 51 large quantities of radioisotopes .101 Officials speculate

Targeting Nuclear EGFR: Strategies for Improving Cetuximab Therapy in Lung Cancer

DTIC Science & Technology

2014-09-01

Triple - negative breast cancer Mol Cancer Ther. 2014 May;13(5):1356-68. PMID: 24634415, PMCID: PMC4013210 6. Brand, TM, Iida, M...Receptor Is a Functional Molecular Target in Triple - Negative Breast Cancer . Molecular cancer therapeutics (2014). 11 26. Iida, M., Brand, T.M...2014). Brand, T.M., et al. Nuclear epidermal growth factor receptor is a functional molecular target in triple - negative breast cancer .

Molecular structure of Mg-Al, Mn-Al and Zn-Al halotrichites-type double sulfates--an infrared spectroscopic study.

PubMed

Palmer, Sara J; Frost, Ray L

2011-05-01

Near infrared (NIR), X-ray diffraction (XRD) and infrared (IR) spectroscopy have been applied to halotrichites of the formula MgAl(2)(SO(4))(4)·22H(2)O, MnAl(2)(SO(4))(4)·22H(2)O and ZnAl(2)(SO(4))(4)·22H(2)O. Comparison of the halotrichites in different spectral regions has shown that the incorporation of a divalent transition metal into the halotrichite structure causes a shift in OH stretching band positions to lower wavenumbers. Therefore, an increase of the hydrogen bond strength of the bonded water is observed for divalent cations with a larger molecular mass. XRD has confirmed the formation of halotrichite for all three samples and characteristic peaks of halotrichite have been identified for each halotrichite-type compound. It has been observed that Mg-Al and Mn-Al halotrichite are very similar in structure, while Zn-Al showed several differences particularly in the NIR spectra. This work has shown that compounds with halotrichite structures can be synthesised and characterised by infrared and NIR spectroscopy. Copyright © 2011 Elsevier B.V. All rights reserved.

The study of voids in the AuAl thin-film system using the nuclear microprobe

NASA Astrophysics Data System (ADS)

de Waal, H. S.; Pretorius, R.; Prozesky, V. M.; Churms, C. L.

1997-07-01

A Nuclear Microprobe (NMP) was used to study void formation in thin film gold-aluminium systems. Microprobe Rutherford Backscattering Spectrometry (μRBS) was utilised to effectively obtain a three-dimensional picture of the void structure on the scale of a few nanometers in the depth dimension and a few microns in the in-plane dimension. This study illustrates the usefulness of the NMP in the study of materials and specifically thin-film structures.

Mechanisms of elevated-temperature deformation in the B2 aluminides NiAl and CoAl

NASA Technical Reports Server (NTRS)

Yaney, D. L.; Nix, W. D.

1988-01-01

A strain rate change technique, developed previously for distinguishing between pure-metal and alloy-type creep behavior, was used to study the elevated-temperature deformation behavior of the intermetallic compounds NiAl and CoAl. Tests on NiAl were conducted at temperatures between 1100 and 1300 K while tests on CoAl were performed at temperatures ranging from 1200 to 1400 K. NiAl exhibits pure-metal type behavior over the entire temperature range studied. CoAl, however, undergoes a transition from pure-metal to alloy-type deformation behavior as the temperature is decreased from 1400 to 1200 K. Slip appears to be inherently more difficult in CoAl than in NiAl, with lattice friction effects limiting the mobility of dislocations at a much higher tmeperature in CoAl than in NiAl. The superior strength of CoAl at elevated temperatures may, therefore, be related to a greater lattice friction strengthening effect in CoAl than in NiAl.

Implications of fALS Mutations on Sod1 Function and Oligomerization in Cell Models.

PubMed

Brasil, Aline A; Magalhães, Rayne S S; De Carvalho, Mariana D C; Paiva, Isabel; Gerhardt, Ellen; Pereira, Marcos D; Outeiro, Tiago F; Eleutherio, Elis C A

2018-06-01

Among the familial forms of amyotrophic lateral sclerosis (fALS), 20% are associated with the Cu,Zn-superoxide dismutase (Sod1). fALS is characterized by the accumulation of aggregated proteins and the increase in oxidative stress markers. Here, we used the non-invasive bimolecular fluorescence complementation (BiFC) assay in human H4 cells to investigate the kinetics of aggregation and subcellular localization of Sod1 mutants. We also studied the effect of the different Sod1 mutants to respond against oxidative stress by following the levels of reactive oxygen species (ROS) after treatment with hydrogen peroxide. Our results showed that only 30% of cells transfected with A4VSod1 showed no inclusions while for the other Sod1 mutants tested (L38V, G93A and G93C), this percentage was at least 70%. In addition, we found that 10% of cells transfected with A4VSod1 displayed more than five inclusions per cell and that A4V and G93A Sod1 formed inclusions more rapidly than L38V and G93C Sod1. Expression of WTSod1 significantly decreased the intracellular oxidation levels in comparison with expression of fALS Sod1 mutants, suggesting the mutations induce a functional impairment. All fALS mutations impaired nuclear localization of Sod1, which is important for maintaining genomic stability. Consistently, expression of WTSod1, but not of fALS Sod1 mutants, reduced DNA damage, as measured by the comet assay. Altogether, our study sheds light into the effects of fALS Sod1 mutations on inclusion formation, dynamics, and localization as well as on antioxidant response, opening novel avenues for investigating the role of fALS Sod1 mutations in pathogenesis.

CVD Fiber Coatings for Al2O3/NiAl Composites

NASA Technical Reports Server (NTRS)

Boss, Daniel E.

1995-01-01

While sapphire-fiber-reinforced nickel aluminide (Al2O3/NiAl) composites are an attractive candidate for high-temperature structures, the significant difference in the coefficient of thermal expansion between the NiAl matrix and the sapphire fiber creates substantial residual stresses in the composite. This study seeks to produce two fiber-coating systems with the potential to reduce the residual stresses in the sapphire/NiAl composite system. Chemical vapor deposition (CVD) was used to produce both the compensating and compliant-fiber coatings for use in sapphire/NiAl composites. A special reactor was designed and built to produce the FGM and to handle the toxic nickel precursors. This process was successfully used to produce 500-foot lengths of fiber with coating thicknesses of approximately 3 microns, 5 microns, and 10 microns.

The Future of Energy from Nuclear Fission

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Son H.; Taiwo, Temitope

Nuclear energy is an important part of our current global energy system, and contributes to supplying the significant demand for electricity for many nations around the world. There are 433 commercial nuclear power reactors operating in 30 countries with an installed capacity of 367 GWe as of October 2011 (IAEA PRIS, 2011). Nuclear electricity generation totaled 2630 TWh in 2010 representing 14% the world’s electricity generation. The top five countries of total installed nuclear capacity are the US, France, Japan, Russia and South Korea at 102, 63, 45, 24, and 21 GWe, respectively (WNA, 2012a). The nuclear capacity of thesemore » five countries represents more than half, 68%, of the total global nuclear capacity. The role of nuclear power in the global energy system today has been motivated by several factors including the growing demand for electric power, the regional availability of fossil resources and energy security concerns, and the relative competitiveness of nuclear power as a source of base-load electricity. There is additional motivation for the use of nuclear power because it does not produce greenhouse gas (GHG) emissions or local air pollutants during its operation and contributes to low levels of emissions throughout the lifecycle of the nuclear energy system (Beerten, J. et. al., 2009). Energy from nuclear fission primarily in the form of electric power and potentially as a source of industrial heat could play a greater role for meeting the long-term growing demand for energy worldwide while addressing the concern for climate change from rising GHG emissions. However, the nature of nuclear fission as a tremendously compact and dense form of energy production with associated high concentrations of radioactive materials has particular and unique challenges as well as benefits. These challenges include not only the safety and cost of nuclear reactors, but proliferation concerns, safeguard and storage of nuclear materials associated with nuclear

Aggregation of ALS-linked FUS mutant sequesters RNA binding proteins and impairs RNA granules formation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Takanashi, Keisuke; Yamaguchi, Atsushi, E-mail: atsyama@restaff.chiba-u.jp

Highlights: • Aggregation of ALS-linked FUS mutant sequesters ALS-associated RNA-binding proteins (FUS wt, hnRNP A1, and hnRNP A2). • Aggregation of ALS-linked FUS mutant sequesters SMN1 in the detergent-insoluble fraction. • Aggregation of ALS-linked FUS mutant reduced the number of speckles in the nucleus. • Overproduced ALS-linked FUS mutant reduced the number of processing-bodies (PBs). - Abstract: Protein aggregate/inclusion is one of hallmarks for neurodegenerative disorders including amyotrophic lateral sclerosis (ALS). FUS/TLS, one of causative genes for familial ALS, encodes a multifunctional DNA/RNA binding protein predominantly localized in the nucleus. C-terminal mutations in FUS/TLS cause the retention and the inclusionmore » of FUS/TLS mutants in the cytoplasm. In the present study, we examined the effects of ALS-linked FUS mutants on ALS-associated RNA binding proteins and RNA granules. FUS C-terminal mutants were diffusely mislocalized in the cytoplasm as small granules in transiently transfected SH-SY5Y cells, whereas large aggregates were spontaneously formed in ∼10% of those cells. hnRNP A1, hnRNP A2, and SMN1 as well as FUS wild type were assembled into stress granules under stress conditions, and these were also recruited to FUS mutant-derived spontaneous aggregates in the cytoplasm. These aggregates stalled poly(A) mRNAs and sequestered SMN1 in the detergent insoluble fraction, which also reduced the number of nuclear oligo(dT)-positive foci (speckles) in FISH (fluorescence in situ hybridization) assay. In addition, the number of P-bodies was decreased in cells harboring cytoplasmic granules of FUS P525L. These findings raise the possibility that ALS-linked C-terminal FUS mutants could sequester a variety of RNA binding proteins and mRNAs in the cytoplasmic aggregates, which could disrupt various aspects of RNA equilibrium and biogenesis.« less

187Re- 187Os Nuclear Geochronometry: Dating Peridotitic Diamond Sulphide Inclusions

NASA Astrophysics Data System (ADS)

Roller, Goetz

2015-04-01

only minor disturbance of the 187Re/188Os nuclear production ratio assigned to the outer core. It cannot be excluded that a major change in oxygen/sulfur fugacitiy across the core - mantle boundary (CMB), coincident with the GOE, is responsible for the 187Re/188Os fractionation of the EL50 sample. Because of its minor degree of fractionation, EL50 can still be used as a so-called fractionated chronometer for dating those Ellendale peridotitic diamond sulphide inclusions, which do not show open system behaviour. Whether the ˜ 1.4 Ga to 1.5 Ga fractionation events are due to an even more pronounced change in oxygen and/or sulfur fugacities across the CMB, within the mantle or, alternatively/additionally, reworking of the mantle because of mantle convection and/or subduction of oceanic crust, remains an open question. This question will be addressed in future studies. [1] Roller (2014), GSA Abstr. with Programs, 46, 323. [2] Roller (2014), Abstract S51B-4444, Fall Meeting, AGU 2014. [3] Burbidge et al. (1957) Revs. Mod. Phys. 29, 547 - 650. [4] Birck et al. (1994), EPSL 124, 139 - 148. [5] Smit et al. (2010) GCA 74, 3292 - 3306.

Decommissioning of the Iraq former nuclear complex

DOE Office of Scientific and Technical Information (OSTI.GOV)

Abbas, Mohammed; Helou, Tuama; Ahmead, Bushra

2007-07-01

Available in abstract form only. Full text of publication follows: A number of sites in Iraq have some degree of radiological contamination and require decommissioning and remediation in order to ensure radiological safety. Many of these sites in Iraq are located at the nuclear research centre at Al Tuwaitha. The International Atomic Energy Agency (IAEA) Board of Governors has approved a project to assist the Government of Iraq in the evaluation and decommissioning of former facilities that used radioactive materials. The project is divided into three phases: Phase 1: collect and analyze all available data and conduct training of themore » Iraqi staff, Phase 2: develop a decommissioning and remediation plan, and Phase 3: implement field activities relating to decommissioning, remediation and site selection suitable for final disposal of waste. Four working groups have been established to complete the Phase 1 work and significant progress has been made in drafting a new nuclear law which will provide the legal basis for the licensing of the decommissioning of the former nuclear complex. Work is also underway to collect and analysis existing date, to prioritize future activities and to develop a waste management strategy. This will be a long-term and costly project. (authors)« less

Synthesis and structure of a stuffed derivative of α-quartz, Mg 0.5AlSiO 4

DOE PAGES

Xu, Hongwu; Heaney, Peter J.; Yu, Ping; ...

2015-10-01

A structural derivative of quartz with the composition Mg 0.5AlSiO 4 has been grown from glass and characterized using synchrotron X-ray diffraction (XRD), transmission electron microscopy (TEM), and 29Si nuclear magnetic resonance (NMR) spectroscopy. Rietveld analysis of the XRD data indicates that the framework of Mg 0.5AlSiO 4 is isostructural with α-quartz, rather than β-quartz, as is consistent with previous theoretical modeling (Sternitzke and Müller 1991). Al and Si exhibit long-range disorder over the framework tetrahedral sites, indicated by the absence of the superlattice reflections corresponding to the doubling of c relative to that of quartz. Nevertheless, 29Si NMR measurementsmore » show that Al and Si exhibit partial short-range order with an ordering degree of 56%. Electron diffraction reveals superlattice reflections indicative of doubled periodicities along the a-axes. In conclusion, Fourier electron density maps show that Mg occupies channel sites that each are bonded to six O atoms, in contrast to the tetrahedral coordination of Li in the β-quartz-type framework for β-eucryptite, LiAlSiO 4. Furthermore, the concentrations of Mg in adjacent channels are different, resulting in framework distortions that generate the superstructures along a.« less

Study on Mg/Al Weld Seam Based on Zn–Mg–Al Ternary Alloy

PubMed Central

Liu, Liming; Liu, Fei; Zhu, Meili

2014-01-01

Based on the idea of alloying welding seams, a series of Zn–xAl filler metals was calculated and designed for joining Mg/Al dissimilar metals by gas tungsten arc (GTA) welding. An infrared thermography system was used to measure the temperature of the welding pool during the welding process to investigate the solidification process. It was found that the mechanical properties of the welded joints were improved with the increasing of the Al content in the Zn–xAl filler metals, and when Zn–30Al was used as the filler metal, the ultimate tensile strength could reach a maximum of 120 MPa. The reason for the average tensile strength of the joint increasing was that the weak zone of the joint using Zn–30Al filler metal was generated primarily by α-Al instead of MgZn2. When Zn–40Al was used as the filler metal, a new transition zone, about 20 μm-wide, appeared in the edge of the fusion zone near the Mg base metal. Due to the transition zones consisting of MgZn2- and Al-based solid solution, the mechanical property of the joints was deteriorated. PMID:28788508

Chemical failure modes of AlQ3-based OLEDs: AlQ3 hydrolysis.

PubMed

Knox, John E; Halls, Mathew D; Hratchian, Hrant P; Schlegel, H Bernhard

2006-03-28

Tris(8-hydroxyquinoline)aluminum(III), AlQ3, is used in organic light-emitting diodes (OLEDs) as an electron-transport material and emitting layer. The reaction of AlQ3 with trace H2O has been implicated as a major failure pathway for AlQ3-based OLEDs. Hybrid density functional calculations have been carried out to characterize the hydrolysis of AlQ3. The thermochemical and atomistic details for this important reaction are reported for both the neutral and oxidized AlQ3/AlQ3+ systems. In support of experimental conclusions, the neutral hydrolysis reaction pathway is found to be a thermally activated process, having a classical barrier height of 24.2 kcal mol(-1). First-principles infrared and electronic absorption spectra are compared to further characterize AlQ3 and the hydrolysis pathway product, AlQ2OH. The activation energy for the cationic AlQ3 hydrolysis pathway is found to be 8.5 kcal mol(-1) lower than for the neutral reaction, which is significant since it suggests a role for charge imbalance in promoting chemical failure modes in OLED devices.

A New ECR Ion Source for Nuclear Astrophysics Studies

NASA Astrophysics Data System (ADS)

Cesaratto, John M.

2008-10-01

The Laboratory for Experimental Nuclear Astrophysics (LENA) is a low energy facility designed to study nuclear reactions of astrophysical interest at energies which are important for nucleosysthesis. In general, these reactions have extremely small cross sections, requiring intense beams and efficient detection systems. Recently, a new, high intensity electron-cyclotron-resonance (ECR) ion source has been constructed (based on a design by Wills et al.[1]), which represents a substantial improvement in the capabilities of LENA. Beam is extracted from an ECR plasma excited at 2.45 GHz and confined by an array of permanent magnets. It has produced H^+ beams in excess of 1 mA on target over the energy range 100 - 200 keV, which greatly increases our ability to measure small cross sections. Initial measurements will focus on the ^23Na(p,γ)^24Mg reaction, which is of interest in a variety of astrophysical scenarios. The present uncertainty in the rate of this reaction is the result of an unobserved resonance expected at Elab =144 keV, which should be detectable using beams from the new ECR source. In collaboration with Arthur E. Champagne and Thomas B. Clegg, University of North Carolina, Chapel Hill and TUNL. [3pt] [1] J. S. C. Wills et al., Rev. Sci. Instrum. 69, 65 (1999).

Epitaxial growth of Al9Ir2 intermetallic compound on Al(100): Mechanism and interface structure

NASA Astrophysics Data System (ADS)

Kadok, J.; Pussi, K.; Šturm, S.; Ambrožič, B.; Gaudry, É.; de Weerd, M.-C.; Fournée, V.; Ledieu, J.

2018-04-01

The adsorption of Ir adatoms on Al(100) has been investigated under various exposures and temperature conditions. The experimental and theoretical results reveal a diffusion of Ir adatoms within the Al(100) surface selvedge already at 300 K. Above 593 K, two domains of a (√{5 }×√{5 }) R 26 .6∘ phase are identified by low energy electron diffraction (LEED) and scanning tunneling microscopy measurements. This phase corresponds to the initial growth of an Al9Ir2 compound at the Al(100) surface. The Al9Ir2 intermetallic domains are terminated by bulklike pure Al layers. The structural stability of Al9Ir2 (001) grown on Al(100) has been analyzed by density functional theory based calculations. Dynamical LEED analysis is consistent with an Ir adsorption leading to the growth of an Al9Ir2 intermetallic compound. We propose that the epitaxial relationship Al9Ir2(001 ) ∥Al (100) and Al9Ir2[100 ] ∥Al [031 ]/[013 ] originates from a matching of Al atomic arrangements present both on Al(100) and on pure Al(001) layers present in the Al9Ir2 compound. Finally, the interface between Al9Ir2 precipitates and the Al matrix has been characterized by transmission electron microscopy measurements. The cross-sectional observations are consistent with the formation of Al9Ir2 (001) compounds. These measurements indicate an important Ir diffusion within Al(100) near the surface region. The coherent interface between Al9Ir2 and the Al matrix is sharp.

Formation of gamma(sup prime)-Ni3Al via the Peritectoid Reaction: gamma + beta (+ Al2O3)=gamma(sup prime)(+ Al2O3)

NASA Technical Reports Server (NTRS)

Copeland, Evan

2008-01-01

The activities of Al and Ni were measured using multi-cell Knudsen effusion-cell mass spectrometry (multi-cell KEMS), over the composition range 8-32 at.%Al and temperature range T=1400-1750 K in the Ni-Al-O system. These measurements establish that equilibrium solidification of gamma(sup prime)-Ni3Al-containing alloys occurs by the eutectic reaction, L (+ Al2O3)=gamma + Beta(+ Al2O3), at 1640 +/- 1 K and a liquid composition of 24.8 +/- 0.2 at.%al (at an unknown oxygen content). The {gamma + Beta (+Al2O3} phase field is stable over the temperature range 1633-1640 K, and gamma(sup prime)-Ni3Al forms via the peritectoid, gamma + Beta (+ Al2O3)=gamma(sup prime) (+ Al2O3), at 1633 +/- 1 K. This behavior is consistent with the current Ni-Al phase diagram and a new diagram is proposed. This new Ni-Al phase diagram explains a number of unusual steady-state solidification structures reported previously and provides a much simpler reaction scheme in the vicinity of the gamma(sup prime)-Ni2Al phase field.

Chemical trend of superconducting transition temperature in hole-doped delafossite of CuAlO2, AgAlO2 and AuAlO2

NASA Astrophysics Data System (ADS)

Nakanishi, Akitaka; Katayama-Yoshida, Hiroshi

2012-12-01

We have performed the first-principles calculations about the superconducting transition temperature Tc of hole-doped delafossite CuAlO2, AgAlO2 and AuAlO2. Calculated Tc are about 50 K (CuAlO2), 40 K (AgAlO2) and 3 K(AuAlO2) at maximum in the optimum hole-doping concentration. The low Tc of AuAlO2 is attributed to the weak electron-phonon interaction caused by the low covalency and heavy atomic mass.

Evaluation of ZnO:Al as a contact material to CdZnTe for radiation detector applications (Conference Presentation)

NASA Astrophysics Data System (ADS)

Roy, Utpal N.; Camarda, Giuseppe S.; Cui, Yonggang; Gul, Rubi; Hossain, Anwar; Yang, Ge; James, Ralph B.; Pradhan, Aswini K.; Mundle, Rajeh

2016-09-01

Aluminum (Al) doped ZnO with very high Al concentration acts as metal regarding its electrical conductivity. ZnO offers many advantages over the commonly-known metals being used today as electrode materials for nuclear detector fabrication. Often, the common metals show poor adhesion to CdZnTe or CdTe surfaces and have a tendency to peel off. In addition, there is a large mismatch of the coefficients of thermal expansion (CTE) between the metals and underlying CdZnTe, which is one of the reasons for mechanical degradation of the contact. In contrast ZnO has a close match of the CTE with CdZnTe and possesses 8-20 times higher hardness than the commonly-used metals. In this presentation, we will explore and discuss the properties of CdZnTe detectors with ZnO:Al contacts.

Atomistic simulation of Al-graphene thin film growth on polycrystalline Al substrate

NASA Astrophysics Data System (ADS)

Zhang, Lan; Zhu, Yongchao; Li, Na; Rong, Yan; Xia, Huimin; Ma, Huizhong

2018-03-01

The growth of Al-Graphene composite coatings on polycrystalline Al substrate was investigated by using classical molecular dynamics (MD) simulations. Unlike the diffusion behaviors on single crystal surface, most of adatoms were easily bound by the steps on polycrystalline Al surface, owing to the local accelerated energy. Both Ehrlich-Schwoebel (ES) barriers and the steering effect backed up the volmer-weber growth mode, which was consistent with the dynamic growth process observed in the deposit. The morphology of composite coatings was significantly affected by graphene flakes. Enrichment of graphene flakes gave rise to an increase of the local thickness, and graphene flakes only existed in Al grain boundaries. The size of Al grains in the composite coating visibly decreased when compared with that in the pure Al coating. This grain refinement and the mechanical property can be reinforced by the increase of graphene flakes.

Understanding of the mechanical and structural changes induced by alpha particles and heavy ions in the French simulated nuclear waste glass

NASA Astrophysics Data System (ADS)

Karakurt, G.; Abdelouas, A.; Guin, J.-P.; Nivard, M.; Sauvage, T.; Paris, M.; Bardeau, J.-F.

2016-07-01

Borosilicate glasses are considered for the long-term confinement of high-level nuclear wastes. External irradiations with 1 MeV He+ ions and 7 MeV Au5+ ions were performed to simulate effects produced by alpha particles and by recoil nuclei in the simulated SON68 nuclear waste glass. To better understand the structural modifications, irradiations were also carried out on a 6-oxides borosilicate glass, a simplified version of the SON68 glass (ISG glass). The mechanical and macroscopic properties of the glasses were studied as function of the deposited electronic and nuclear energies. Alpha particles and gold ions induced a volume change up to -0.7% and -2.7%, respectively, depending on the glass composition. Nano-indentations tests were used to determine the mechanical properties of the irradiated glasses. A decrease of about -22% to -38% of the hardness and a decrease of the reduced Young's modulus by -8% were measured after irradiations. The evolution of the glass structure was studied by Raman spectroscopy, and also 11B and 27Al Nuclear Magnetic Resonance (MAS-NMR) on a 20 MeV Kr irradiated ISG glass powder. A decrease of the silica network connectivity after irradiation with alpha particles and gold ions is deduced from the structural changes observations. NMR spectra revealed a partial conversion of BO4 to BO3 units but also a formation of AlO5 and AlO6 species after irradiation with Kr ions. The relationships between the mechanical and structural changes are also discussed.

Insulator-semiconductor interface fixed charges in AlGaN/GaN metal-insulator-semiconductor devices with Al2O3 or AlTiO gate dielectrics

NASA Astrophysics Data System (ADS)

Le, Son Phuong; Nguyen, Duong Dai; Suzuki, Toshi-kazu

2018-01-01

We have investigated insulator-semiconductor interface fixed charges in AlGaN/GaN metal-insulator-semiconductor (MIS) devices with Al2O3 or AlTiO (an alloy of Al2O3 and TiO2) gate dielectrics obtained by atomic layer deposition on AlGaN. Analyzing insulator-thickness dependences of threshold voltages for the MIS devices, we evaluated positive interface fixed charges, whose density at the AlTiO/AlGaN interface is significantly lower than that at the Al2O3/AlGaN interface. This and a higher dielectric constant of AlTiO lead to rather shallower threshold voltages for the AlTiO gate dielectric than for Al2O3. The lower interface fixed charge density also leads to the fact that the two-dimensional electron concentration is a decreasing function of the insulator thickness for AlTiO, whereas being an increasing function for Al2O3. Moreover, we discuss the relationship between the interface fixed charges and interface states. From the conductance method, it is shown that the interface state densities are very similar at the Al2O3/AlGaN and AlTiO/AlGaN interfaces. Therefore, we consider that the lower AlTiO/AlGaN interface fixed charge density is not owing to electrons trapped at deep interface states compensating the positive fixed charges and can be attributed to a lower density of oxygen-related interface donors.

26Al- 26Mg and 207Pb- 206Pb systematics of Allende CAIs: Canonical solar initial 26Al/ 27Al ratio reinstated

NASA Astrophysics Data System (ADS)

Jacobsen, Benjamin; Yin, Qing-zhu; Moynier, Frederic; Amelin, Yuri; Krot, Alexander N.; Nagashima, Kazuhide; Hutcheon, Ian D.; Palme, Herbert

2008-07-01

The precise knowledge of the initial 26Al/ 27Al ratio [( 26Al/ 27Al) 0] is crucial if we are to use the very first solid objects formed in our Solar System, calcium-aluminum-rich inclusions (CAIs) as the "time zero" age-anchor and guide future work with other short-lived radio-chronometers in the early Solar System, as well as determining the inventory of heat budgets from radioactivities for early planetary differentiation. New high-precision multi-collector inductively-coupled plasma mass spectrometry (MC-ICP-MS) measurements of 27Al/ 24Mg ratios and Mg-isotopic compositions of nine whole-rock CAIs (six mineralogically characterized fragments and three micro-drilled inclusions) from the CV carbonaceous chondrite, Allende yield a well-defined 26Al- 26Mg fossil isochron with an ( 26Al/ 27Al) 0 of (5.23 ± 0.13) × 10 - 5 . Internal mineral isochrons obtained for three of these CAIs ( A44A, AJEF, and A43) are consistent with the whole-rock CAI isochron. The mineral isochron of AJEF with ( 26Al/ 27Al) 0 = (4.96 ± 0.25) × 10 - 5 , anchored to our precisely determined absolute 207Pb- 206Pb age of 4567.60 ± 0.36 Ma for the same mineral separates, reinstate the "canonical" ( 26Al/ 27Al) 0 of 5 × 10 - 5 for the early Solar System. The uncertainty in ( 26Al/ 27Al) 0 corresponds to a maximum time span of ± 20 Ka (thousand years), suggesting that the Allende CAI formation events were culminated within this time span. Although all Allende CAIs studied experienced multistage formation history, including melting and evaporation in the solar nebula and post-crystallization alteration likely on the asteroidal parent body, the 26Al- 26Mg and U-Pb-isotopic systematics of the mineral separates and bulk CAIs behaved largely as closed-system since their formation. Our data do not support the "supra-canonical" 26Al/ 27Al ratio of individual minerals or their mixtures in CV CAIs, suggesting that the supra-canonical 26Al/ 27Al ratio in the CV CAIs may have resulted from post

Condensins exert force on chromatin-nuclear envelope tethers to mediate nucleoplasmic reticulum formation in Drosophila melanogaster.

PubMed

Bozler, Julianna; Nguyen, Huy Q; Rogers, Gregory C; Bosco, Giovanni

2014-12-30

Although the nuclear envelope is known primarily for its role as a boundary between the nucleus and cytoplasm in eukaryotes, it plays a vital and dynamic role in many cellular processes. Studies of nuclear structure have revealed tissue-specific changes in nuclear envelope architecture, suggesting that its three-dimensional structure contributes to its functionality. Despite the importance of the nuclear envelope, the factors that regulate and maintain nuclear envelope shape remain largely unexplored. The nuclear envelope makes extensive and dynamic interactions with the underlying chromatin. Given this inexorable link between chromatin and the nuclear envelope, it is possible that local and global chromatin organization reciprocally impact nuclear envelope form and function. In this study, we use Drosophila salivary glands to show that the three-dimensional structure of the nuclear envelope can be altered with condensin II-mediated chromatin condensation. Both naturally occurring and engineered chromatin-envelope interactions are sufficient to allow chromatin compaction forces to drive distortions of the nuclear envelope. Weakening of the nuclear lamina further enhanced envelope remodeling, suggesting that envelope structure is capable of counterbalancing chromatin compaction forces. Our experiments reveal that the nucleoplasmic reticulum is born of the nuclear envelope and remains dynamic in that they can be reabsorbed into the nuclear envelope. We propose a model where inner nuclear envelope-chromatin tethers allow interphase chromosome movements to change nuclear envelope morphology. Therefore, interphase chromatin compaction may be a normal mechanism that reorganizes nuclear architecture, while under pathological conditions, such as laminopathies, compaction forces may contribute to defects in nuclear morphology. Copyright © 2015 Bozler et al.

Effects of Al(III) and Nano-Al13 Species on Malate Dehydrogenase Activity

PubMed Central

Yang, Xiaodi; Cai, Ling; Peng, Yu; Li, Huihui; Chen, Rong Fu; Shen, Ren Fang

2011-01-01

The effects of different aluminum species on malate dehydrogenase (MDH) activity were investigated by monitoring amperometric i-t curves for the oxidation of NADH at low overpotential using a functionalized multi-wall nanotube (MWNT) modified glass carbon electrode (GCE). The results showed that Al(III) and Al13 can activate the enzymatic activity of MDH, and the activation reaches maximum levels as the Al(III) and Al13 concentration increase. Our study also found that the effects of Al(III) and Al13 on the activity of MDH depended on the pH value and aluminum speciation. Electrochemical and circular dichroism spectra methods were applied to study the effects of nano-sized aluminum compounds on biomolecules. PMID:22163924

Effects of Al(III) and nano-Al13 species on malate dehydrogenase activity.

PubMed

Yang, Xiaodi; Cai, Ling; Peng, Yu; Li, Huihui; Chen, Rong Fu; Shen, Ren Fang

2011-01-01

The effects of different aluminum species on malate dehydrogenase (MDH) activity were investigated by monitoring amperometric i-t curves for the oxidation of NADH at low overpotential using a functionalized multi-wall nanotube (MWNT) modified glass carbon electrode (GCE). The results showed that Al(III) and Al(13) can activate the enzymatic activity of MDH, and the activation reaches maximum levels as the Al(III) and Al(13) concentration increase. Our study also found that the effects of Al(III) and Al(13) on the activity of MDH depended on the pH value and aluminum speciation. Electrochemical and circular dichroism spectra methods were applied to study the effects of nano-sized aluminum compounds on biomolecules.

Fracture toughness of Ti-Al3Ti-Al-Al3Ti laminate composites under static and cyclic loading conditions

NASA Astrophysics Data System (ADS)

Patselov, A. M.; Gladkovskii, S. V.; Lavrikov, R. D.; Kamantsev, I. S.

2015-10-01

The static and cyclic fracture toughnesses of a Ti-Al3Ti-Al-Al3Ti laminate composite material containing at most 15 vol % intermetallic compound are studied. Composite specimens are prepared by terminating reaction sintering of titanium and aluminum foils under pressure. The fracture of the titanium layers is quasi-cleavage during cyclic crack growth and is ductile during subsequent static loading.

Radioactive Waste Management and Nuclear Facility Decommissioning Progress in Iraq - 13216

DOE Office of Scientific and Technical Information (OSTI.GOV)

Al-Musawi, Fouad; Shamsaldin, Emad S.; Jasim, Hadi

2013-07-01

Management of Iraq's radioactive wastes and decommissioning of Iraq's former nuclear facilities are the responsibility of Iraq's Ministry of Science and Technology (MoST). The majority of Iraq's former nuclear facilities are in the Al-Tuwaitha Nuclear Research Center located a few kilometers from the edge of Baghdad. These facilities include bombed and partially destroyed research reactors, a fuel fabrication facility and radioisotope production facilities. Within these facilities are large numbers of silos, approximately 30 process or waste storage tanks and thousands of drums of uncharacterised radioactive waste. There are also former nuclear facilities/sites that are outside of Al-Tuwaitha and these includemore » the former uranium processing and waste storage facility at Jesira, the dump site near Adaya, the former centrifuge facility at Rashdiya and the former enrichment plant at Tarmiya. In 2005, Iraq lacked the infrastructure needed to decommission its nuclear facilities and manage its radioactive wastes. The lack of infrastructure included: (1) the lack of an organization responsible for decommissioning and radioactive waste management, (2) the lack of a storage facility for radioactive wastes, (3) the lack of professionals with experience in decommissioning and modern waste management practices, (4) the lack of laws and regulations governing decommissioning or radioactive waste management, (5) ongoing security concerns, and (6) limited availability of electricity and internet. Since its creation eight years ago, the MoST has worked with the international community and developed an organizational structure, trained staff, and made great progress in managing radioactive wastes and decommissioning Iraq's former nuclear facilities. This progress has been made, despite the very difficult implementing conditions in Iraq. Within MoST, the Radioactive Waste Treatment and Management Directorate (RWTMD) is responsible for waste management and the Iraqi

Photoluminescence and Optically Stimulated Luminescence Studies of LiAlO2 and LiGaO2 Crystals

DTIC Science & Technology

2015-03-26

tests from the past. In terms of personal dosimetry, OSL dosimeters could potentially replace ther- moluminescence dosimeters (TLDs) which are widely...used by individuals conducting research and maintaining nuclear weapons ( OSL dosimeters are a promising alterna- tive to TLDs because they do not...because they contain lithium, unlike Al2O3:C, the most commonly used OSL dosimeter [2]. The large neutron 1 cross section of lithium-6 makes enriched

Analysis of dinosaur samples by nuclear microscopy

NASA Astrophysics Data System (ADS)

Wu, Xiankang; Orlić, I.; Tang, S. M.; Wang, Yiming; Wang, Xiaohong; Zhu, Jieqing

1997-07-01

Several dinosaur bone and eggshell fossil samples unearthed at different sites in China were analyzed by means of nuclear microscopy. Concentrations and distributions of elements such as Na, Mg, Al, P, S, Ca, Cr, Mn, Fe, Cu, Zn, As, Br, Sr, Y, Ce, Pb and U, etc. were obtained for each sample. The results of quantitative PIXE and RBS analyses show unusually high concentrations of U and Ce in several samples obtained from a period near the K-T boundary (between Cretaceous and Tertiary periods, 65 million years ago), suggesting that some form of environmental pollution could be the cause of dinosaur extinction.

Co-existence of a few and sub micron inhomogeneities in Al-rich AlGaN/AlN quantum wells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Iwata, Yoshiya; Oto, Takao; Banal, Ryan G.

2015-03-21

Inhomogeneity in Al-rich AlGaN/AlN quantum wells is directly observed using our custom-built confocal microscopy photoluminescence (μ-PL) apparatus with a reflective system. The μ-PL system can reach the AlN bandgap in the deep ultra-violet spectral range with a spatial resolution of 1.8 μm. In addition, cathodoluminescence (CL) measurements with a higher spatial resolution of about 100 nm are performed. A comparison of the μ-PL and CL measurements reveals that inhomogeneities, which have different spatial distributions of a few- and sub-micron scales that are superimposed, play key roles in determining the optical properties.

Thorium-229 solid-state nuclear clock prospects in MgF2 and LiSAF

NASA Astrophysics Data System (ADS)

Meyer, Edmund; Barker, Beau; Collins, Lee

2016-05-01

The 229 Th isomer is thought to be a good candidate for a nuclear clock based on its relatively low-energy isomer excitation of ~ 7 . 8 eV. We report on the study of Th atoms embedded in two crystals, MgF2 and LiSAF (LiSrAlF6). For MgF2 we perform an oxidation study to find the preferred ionization state of the Th atom in the crystal; Thn+, where n = 2 - 4 . We find that the preferred state is n = 4 which requires two interstitial Fluorine atoms to charge compensate. Using the results of MgF2 we then search within LiSAF for suitable dopant sites (the Sr, Al, or Li can all serve). Employing a standard density functional package using a plane-wave basis and psuedopotentials, we optimize a doped cell of increasing particle number sizes and use this to estimate the dilute doped-limit band-gap of LiSAF. Placement of the dopant on the Sr and Al sites with accompanying double and single F interstitial atom placements is also studied to determine the ground state, and comparisons are made with previous calculations. In both crystal ground states, we find that the band gap is large enough for the observation of the 229 Th nuclear isomer transition; > 9 eV.

Medical History in the Hellenic Journal of Nuclear Medicine.

PubMed

Otte, Andreas

2017-01-01

biological views of the "atomic" philosophers, Leucippus and Democritus. E. Magiorkinis. A. Beloukas, A. Diamantis. 2010; 13(2): 111-117. http://nuclmed.web.auth.gr/magazine/eng/may10/9.pdf Correspondence. Neuroimaging in mild traumatic brain injury and M. Ravel's injury. A. Otte. 2012; 15(1): 76. http://nuclmed. web.auth.gr/magazine/eng/jan12/3.pdf Selected Brief Contributions. The "atomic theory" of Leucippus, and its impact on medicine before Hippocrates. G. Tsoucalas, K. Laios et al. 2013; 16(1): 68-9. http://nuclmed.web.auth.gr/magazine/eng/jan13/72.pdf Selected Brief Contributions. Computed tomography alone reveals the secrets of ancient mummies in medical archaeology. A. Otte, T. Thieme et al. 2013; 16(2): 148-9. http://nuclmed.web.auth.gr/magazine/eng/may13/70.pdf Editorial. The timeless influence of Hippocratic ideas on diet, salicylates and personalized medicine. T.C. Karagiannis. 2014; 17(1): 2-6. http://nuclmed.web.auth.gr/magazine/eng/jan14/1.pdf Historical Article. The physician who first applied radiotherapy, Victor Despeignes, on 1896. M. Sgantzos, G. Tsoucalas et al. 2014; 17(1): 45-6. http://nuclmed.web.auth.gr/magazine/eng/jan14/11.pdf Original Articles. Medical practice applied in the ancient Asclepeion in Kos island. M. Mironidou-Tzouveleki, P.M. Tzitzis. 2014; 17(3): 167-70. http://www.nuclmed.web.auth.gr/magazine/eng/sept14/3.pdf Special Historical Article. How a tertiary medical nuclear medicine department at the Himalayan area in India can be established and function in an exemplary manner. Basic rules revisited. V.K. Dhingra, S. Saini et al. 2015; 18(3): 252-6. http:// nuclmed.web.auth.gr/magazine/eng/sept15/13.pdf Historical and Commentary Note. Johann Sebastian Bach's "Goldberg variations" to treat insomnia from renal lithiasis pain. Sleep research in Nuclear Medicine. A. Otte. 2016; 19(1): 13-4. http://nuclmed.web.auth.gr/magazine/eng/jan16/06.pdf Historical Review. The first medical ethics and deontology in Europe as derived from Greek mythology

Aluminium (Al) speciation in serum and urine after subcutaneous venom immunotherapy with Al as adjuvant.

PubMed

Michalke, Bernhard; Kramer, Matthias F; Brehler, Randolf

2018-02-21

Aluminium is associated with disorders and is the commonly used vaccine adjuvant. Understanding the mechanisms of how Al is transported, metabolized or of its toxicity depends on the knowledge of Al-interactions with bioligands, i.e. Al-species. Al-speciation in serum is difficult because of low concentration and the risk of exogenous Al contamination. Furthermore, Al-measurements may be hampered according to various interferences. This study aims for developing quality controlled protocols for reliable Al- and Al-species determination and for investigating probable differences in Al (-speciation) after Al-containing subcutaneous immunotherapy (SIT). Sample donors were recruited either for the control group ("class-0", they never had been treated with SIT containing an Al-depot extract) or for the SIT-group ("class-1", they previously had been treated with SIT for insect venom allergy with an Al-depot extract). Blood was drawn for medical reasons and serum prepared. Additionally, some sample donors collected 24-h-urine. They had been informed (and they consented) about the scientific use of their samples. The study was approved by the ethic committee of the "Medical Association Westphalia-Lippe" and of the University of Münster, evaluating the study positively (No. 2013-667-f-S). We applied quality controlled sample preparation and interference-free Al detection by ICP sectorfield-mass spectrometry. Al-species were analysed using size-exclusion-chromatography-ICP-qMS. Al-concentrations or speciation in urine samples showed no differences between class-0 and class-1. Al-citrate was the main uric Al-species. In serum elevated Al-concentrations were found for both classes, with class-1 samples being significantly higher than class-0 (p = 0.041), but class-0 samples being approximately 10-fold too high compared to reference values from non-exposed persons. We identified gel-monovettes as contamination source. In contamination-free samples from HNO 3 -prewashed gel

Stellar MHD and Nuclear Physics Coupled Together Solve the Puzzle of Oxide Grain Composition

NASA Astrophysics Data System (ADS)

Palmerini, Sara; Trippella, Oscar; Busso, Maurizio; La Cognata, Marco; Petrelli, Maurizio; Zucchini, Azzurra

Oxide grains, enclosed in meteorites, give us very precise information about the stars in which they formed. Grains belonging to group 1 and 2 are characterized by values of 17O/16O and 18O/16O inconsistent with explosive nucleosynthesis scenarios, and are then believed to form in low mass stars. Nowadays, models of non convective mixing coupled with nuclear burning succeed in reproducing the oxygen isotopic mix found in these ancient solids thanks to the more accurate nuclear physics inputs employed in calculations. However, a large part of oxide grains shows values of the 26Al/27Al isotopic ratio too high to be accounted for by the mixing models mentioned above. Recently, [1] demonstrated that the stellar magnetic field might promote the transport of material across the stellar radiative layers. We apply this magnetic mixing model to a 1.2M ⊙ AGB star of solar metallicity. It turns out that the oxygen and aluminum isotopic ratios shown by group 1 and 2 grains are perfectly reproduced.

Synthesis of core-shell AlOOH hollow nanospheres by reacting Al nanoparticles with water

NASA Astrophysics Data System (ADS)

Lozhkomoev, A. S.; Glazkova, E. A.; Bakina, O. V.; Lerner, M. I.; Gotman, I.; Gutmanas, E. Y.; Kazantsev, S. O.; Psakhie, S. G.

2016-05-01

A novel route for the synthesis of boehmite nanospheres with a hollow core and the shell composed of highly crumpled AlOOH nanosheets by oxidizing Al nanopowder in pure water under mild processing conditions is described. The stepwise events of Al transformation into boehmite are followed by monitoring the pH in the reaction medium. A mechanism of formation of hollow AlOOH nanospheres with a well-defined shape and crystallinity is proposed which includes the hydration of the Al oxide passivation layer, local corrosion of metallic Al accompanied by hydrogen evolution, the rupture of the protective layer, the dissolution of Al from the particle interior and the deposition of AlOOH nanosheets on the outer surface. In contrast to previously reported methods of boehmite nanoparticle synthesis, the proposed method is simple, and environmentally friendly and allows the generation of hydrogen gas as a by-product. Due to their high surface area and high, slit-shaped nanoporosity, the synthesized AlOOH nanostructures hold promise for the development of more effective catalysts, adsorbents, vaccines and drug carriers.

Millimeter distance effects of surface plasmon polaritons in electroformed Al-Al2O3-Ag diodes

NASA Astrophysics Data System (ADS)

Hickmott, T. W.

2017-02-01

Electroforming of metal-insulator-metal diodes is a soft dielectric breakdown that changes the high resistance of as-prepared diodes to a low resistance state. Electroforming of Al-Al2O3-metal diodes with anodic Al2O3 results in voltage-controlled negative resistance in the current-voltage (I-V) characteristics, electroluminescence (EL), and electron emission into vacuum (EM). EL is due to electrons injected at the Al-Al2O3 interface combining with radiative defects in Al2O3. Surface plasmon polaritons (SPPs) are electromagnetic waves that can be excited by photons or electrons. SPPs are confined to a metal-dielectric interface, cause large electric fields in the metal and dielectric, and have ranges of micrometers. The temperature dependence of I-V curves, EL, and EM of a group of electroformed Al-Al2O3-Ag diodes with Al2O3 thicknesses between 12 nm and 20 nm, group A, was measured between 200 K and 300 K. After a sequence of temperature measurements, the Al-Al2O3-Ag diodes, the Al-Al2O3 regions between diodes, and portions of the Ag on the glass region that provides contacts to the diodes are darkened. The range of darkening is >7 mm in a diode with 12 nm of Al2O3 and 2.0-3.5 mm in diodes with Al2O3 thicknesses between 14 nm and 20 nm. Darkening is attributed to the occurrence of SPPs generated by EL photons at the Ag-Al2O3 and Al-Al2O3 interfaces. The results are compared to a second group of Al-Al2O3-Ag diodes with identical Al2O3 thicknesses, group B, that were prepared in the same way as the diodes of group A except for a difference in the deposition of Al films for the two groups. Al-Al2O3-Ag diodes of group B exhibit enhanced EL, which is attributed to spontaneous emission of recombination centers in Al2O3 being enhanced by large electromagnetic fields that are due to SPPs that are generated by EL photons.

Electronic transport through Al/InN nanowire/Al junctions

DOE PAGES

Lu, Tzu -Ming; Wang, George T.; Pan, Wei; ...

2016-02-10

We report non-linear electronic transport measurement of Al/Si-doped n-type InN nanowire/Al junctions performed at T = 0.3 K, below the superconducting transition temperature of the Al electrodes. The proximity effect is observed in these devices through a strong dip in resistance at zero bias. In addition to the resistance dip at zero bias, several resistance peaks can be identified at bias voltages above the superconducting gap of the electrodes, while no resistance dip is observed at the superconducting gap. The resistance peaks disappear as the Al electrodes turn normal beyond the critical magnetic field except one which remains visible atmore » fields several times higher than critical magnetic field. An unexpected non-monotonic magnetic field dependence of the peak position is observed. As a result, we discuss the physical origin of these observations and propose that the resistance peaks could be the McMillan-Rowell oscillations arising from different closed paths localized near different regions of the junctions.« less

Rechargeable Al/Cl2 battery with molten AlCl4/-/ electrolyte.

NASA Technical Reports Server (NTRS)

Holleck, G. L.; Giner, J.; Burrows, B.

1972-01-01

A molten salt system based on Al- and Cl2 carbon electrodes, with an AlCl3 alkali chloride eutectic as electrolyte, offers promise as a rechargeable, high energy density battery which can operate at a relatively low temperature. Electrode kinetic studies showed that the electrode reactions at the Al anode were rapid and that the observed passivation phenomena were due to the formation at the electrode surface of a solid salt layer resulting from concentration changes on anodic or cathodic current flow. It was established that carbon electrodes were intrinsically active for chlorine reduction in AlCl3-alkali chloride melts. By means of a rotating vitreous carbon disk electrode, the kinetic parameters were determined.

Two-Phase Eutectic Growth in Al-Cu and Al-Cu-Ag

NASA Astrophysics Data System (ADS)

Senninger, Oriane; Peters, Matthew; Voorhees, Peter W.

2018-02-01

The microstructure developed by two-phase lamellar eutectics (α ) -(θ {-Al}2{Cu}) in Al-Cu and Al-Cu-Ag alloys is analyzed. A model of two-phase eutectic growth in multicomponent alloys is used to determine the scaling law of the eutectic microstructure using the alloy thermophysical properties. The application of the model to these alloys shows that the addition of Ag to Al-Cu alloys does not significantly change the length scale of the microstructure, which is in agreement with previous experimental studies. This is explained by the combined phenomena of the decrease in interface energies with the addition of Ag and the superheating of the (α ) phase interface induced by the Ag composition profile.

Hot Corrosion Behavior of Stainless Steel with Al-Si/Al-Si-Cr Coating

NASA Astrophysics Data System (ADS)

Fu, Guangyan; Wu, Yongzhao; Liu, Qun; Li, Rongguang; Su, Yong

2017-03-01

The 1Cr18Ni9Ti stainless steel with Al-Si/Al-Si-Cr coatings is prepared by slurry process and vacuum diffusion, and the hot corrosion behavior of the stainless steel with/without the coatings is studied under the condition of Na2SO4 film at 950 °C in air. Results show that the corrosion kinetics of stainless steel, the stainless steel with Al-Si coating and the stainless steel with Al-Si-Cr coating follow parabolic laws in several segments. After 24 h corrosion, the sequence of the mass gain for the three alloys is the stainless steel with Al-Si-Cr coating < the stainless steel with Al-Si coating < the stainless steel without any coating. The corrosion products of the three alloys are layered. Thereinto, the corrosion products of stainless steel without coating are divided into two layers, where the outside layer contains a composite of Fe2O3 and FeO, and the inner layer is Cr2O3. The corrosion products of the stainless steel with Al-Si coating are also divided into two layers, of which the outside layer mainly consists of Cr2O3, and the inner layer is mainly SiO2. The corrosion film of the stainless steel with Al-Si-Cr coating is thin and dense, which combines well with substrate. Thereinto, the outside layer is mainly Cr2O3, and the inside layer is Al2O3. In the matrix of all of the three alloys, there exist small amount of sulfides. Continuous and protective films of Cr2O3, SiO2 and Al2O3 form on the surface of the stainless steel with Al-Si and Al-Si-Cr coatings, which prevent further oxidation or sulfide corrosion of matrix metals, and this is the main reason for the much smaller mass gain of the two alloys than that of the stainless steel without any coatings in the 24 h hot corrosion process.

Multilayer (TiN, TiAlN) ceramic coatings for nuclear fuel cladding

NASA Astrophysics Data System (ADS)

Alat, Ece; Motta, Arthur T.; Comstock, Robert J.; Partezana, Jonna M.; Wolfe, Douglas E.

2016-09-01

In an attempt to develop an accident-tolerant fuel (ATF) that can delay the deleterious consequences of loss-of-coolant-accidents (LOCA), multilayer coatings were deposited onto ZIRLO® coupon substrates by cathodic arc physical vapor deposition (CA-PVD). Coatings were composed of alternating TiN (top) and Ti1-xAlxN (2-layer, 4-layer, 8-layer and 16-layer) layers. The minimum TiN top coating thickness and coating architecture were optimized for good corrosion and oxidation resistance. Corrosion tests were performed in static pure water at 360 °C and 18.7 MPa for up to 90 days. The optimized coatings showed no spallation/delamination and had a maximum of 6 mg/dm2 weight gain, which is 6 times smaller than that of a control sample of uncoated ZIRLO® which showed a weight gain of 40.2 mg/dm2. The optimized architecture features a ∼1 μm TiN top layer to prevent boehmite phase formation during corrosion and a TiN/TiAlN 8-layer architecture which provides the best corrosion performance.

A new "off-on" fluorescent probe for Al(3+) in aqueous solution based on rhodamine B and its application to bioimaging.

PubMed

Huang, Qi; Zhang, Qingyou; Wang, Enze; Zhou, Yanmei; Qiao, Han; Pang, Lanfang; Yu, Fang

2016-01-05

In this paper, a new fluorescent probe has been synthesized and applied as "off-on" sensor for the detection of Al(3+) with a high sensitivity and excellent selectivity in aqueous media. The sensor was easily prepared by one step reaction between rhodamine B hydrazide and pyridoxal hydrochloride named RBP. The structure of the sensor has been characterized by nuclear magnetic resonance and electron spray ionization-mass spectrometry. The fluorescence intensity and absorbance for the sensor showed a good linearity with the concentration of Al(3+) in the range of 0-12.5μM and 8-44μM, respectively, with detection limits of 0.23μM and 1.90μM. The sensor RBP was preliminarily applied to the determination of Al(3+) in water samples from the lake of Henan University and tap water with satisfying results. Moreover, it can be used as a bioimaging reagent for imaging of Al(3+) in living cells. Copyright © 2015 Elsevier B.V. All rights reserved.

Microstructural and Phase Composition Differences Across the Interfaces in Al/Ti/Al Explosively Welded Clads

NASA Astrophysics Data System (ADS)

Fronczek, Dagmara Malgorzata; Chulist, Robert; Litynska-Dobrzynska, Lidia; Lopez, Gabriel Alejandro; Wierzbicka-Miernik, Anna; Schell, Norbert; Szulc, Zygmunt; Wojewoda-Budka, Joanna

2017-09-01

The microstructure and phase composition of Al/Ti/Al interfaces with respect to their localization were investigated. An aluminum-flyer plate exhibited finer grains located close to the upper interface than those present within the aluminum-base plate. The same tendency, but with a higher number of twins, was observed for titanium. Good quality bonding with a wavy shape and four intermetallic phases, namely, TiAl3, TiAl, TiAl2, and Ti3Al, was only obtained at the interface closer to the explosive material. The other interface was planar with three intermetallic compounds, excluding the metastable TiAl2 phase. As a result of a 100-hour annealing at 903 K (630 °C), an Al/TiAl3/Ti/TiAl3/Al sandwich was manufactured, formed with single crystalline Al layers. A substantial difference between the intermetallic layer thicknesses was measured, with 235.3 and 167.4 µm obtained for the layers corresponding to the upper and lower interfaces, respectively. An examination by transmission electron microscopy of a thin foil taken from the interface area after a 1-hour annealing at 825 K (552 °C) showed a mixture of randomly located TiAl3 grains within the aluminum. Finally, the hardness results were correlated with the microstructural changes across the samples.

The Nuclear Power/Nuclear Weapons Connection.

ERIC Educational Resources Information Center

Totten, Sam; Totten, Martha Wescoat

1985-01-01

Once they have nuclear power, most countries will divert nuclear materials from commercial to military programs. In excerpts from the book "Facing the Danger" (by Totten, S. and M. W., Crossing Press, 1984), five anti-nuclear activists explain how and why they have been addressing the nuclear connection. (RM)

The absence of p53 during Human Cytomegalovirus infection leads to decreased UL53 expression, disrupting UL50 localization to the inner nuclear membrane, and thereby inhibiting capsid nuclear egress

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kuan, Man I; O’Dowd, John M.; Fortunato, Elizabeth

Our electron microscopy study (Kuan et al., 2016) found HCMV nuclear capsid egress was significantly reduced in p53 knockout cells (p53KOs), correlating with inhibited formation of infoldings of the inner nuclear membrane (IINMs). Molecular examination of these phenomena has found p53KOs expressed UL97 and phosphorylated lamins, however the lamina failed to remodel. The nuclear egress complex (NEC) protein UL50 was expressed in almost all cells. UL50 re-localized to the inner nuclear membrane (INM) in ~90% of wt cells, but only ~35% of p53KOs. UL53 expression was significantly reduced in p53KOs, and cells lacking UL50 nuclear staining, expressed no UL53. Re-introductionmore » of p53 into p53KOs largely recovered UL53 positivity and UL50 nuclear re-localization. Nuclear rim located UL50/53 puncta, which co-localized with the major capsid protein, were largely absent in p53KOs. We believe these puncta were IINMs. In the absence of p53, UL53 expression was inhibited, disrupting formation of the NEC/IINMs, and reducing functional virion secretion. -- Highlights: •Phosphorylated nuclear lamins were inefficiently remodeled in p53KO cells. •p53KO cells expressed UL50, but it was not efficiently targeted to the nuclear rim. •UL53 was not expressed in the large majority of p53KO cells. •Cells failing to express UL53 did not localize UL50 to the nucleus. •NEC puncta/infoldings of the inner nuclear membrane were scarce in p53KO cells.« less

The β decay of 34,35Mg and the structure of 34Al

NASA Astrophysics Data System (ADS)

Rajabali, Mustafa; Griffin Collaboration On Experiment S1367 Team

2016-09-01

Nuclei in the island of inversion, near the N = 20 shell closure, exhibit a fascinating behavior where the nuclear ground states show deformed configurations dominated by particle-hole excitations across the neutron shell gap. The 31-35Mg nuclei are in or at the border of this island displaying intruder ground-state configurations, while the 31-35Al isotopes are suggested to have mixed ground-state configurations of normal and intruder type and thus serve as a transition from intruder dominated Mg isotopes to the normal ground-state configuration in Si isotopes. An experiment was performed at the TRIUMF-ISAC-I facility with the goal of populating states in 33-35Al via the beta decay of 33-35Mg. Mg ions were produced, transported and implanted onto a moving Mylar tape at the center of the GRIFFIN spectrometer. Results obtained from the analysis of the 34,35Mg decay data from this experiment will be presented. This includes the half-lives of 34,35Mg and 34,35Al which clarify current conflicting information in the literature. This work is supported by Tennessee Technological University Research Office, the Canadian Founda- tion for Innovation, the National Research Council of Canada and the Natural Sciences and Engineering Research Council of Canada.

Response of rice to Al stress and identification of quantitative trait Loci for Al tolerance.

PubMed

Ma, Jian Feng; Shen, Renfang; Zhao, Zhuqing; Wissuwa, Matthias; Takeuchi, Yoshinobu; Ebitani, Takeshi; Yano, Masahiro

2002-06-01

Rice (Oryza sativa L.) shows the highest tolerance to Al toxicity among small-grain cereal crops, however, the mechanisms and genetics responsible for its high Al tolerance are not yet well understood. We investigated the response of rice to Al stress using the japonica variety Koshihikari in comparison to the indica variety Kasalath. Koshihikari showed higher tolerance at various Al concentrations than Kasalath. The Al content in root apexes was less in Koshihikari than in Kasalath, suggesting that exclusion mechanisms rather than internal detoxification are acting in Koshihikari. Al-induced secretion of citrate was observed in both Koshihikari and Kasalath, however, it is unlikely to be the mechanism for Al tolerance because there was no significant difference in the amount of citrate secreted between Koshihikari and Kasalath. Quantitative trait loci (QTLs) for Al tolerance were mapped in a population of 183 backcross inbred lines (BILs) derived from a cross of Koshihikari and Kasalath. Three putative QTLs controlling Al tolerance were detected on chromosomes 1, 2 and 6. Kasalath QTL alleles on chromosome 1 and 2 reduced Al tolerance but increased tolerance on chromosome 6. The three QTLs explained about 27% of the phenotypic variation in Al tolerance. The existence of QTLs for Al tolerance was confirmed in substitution lines for corresponding chromosomal segments.

Results of a Direct Search Using Synchrotron Radiation for the Low-Energy 229Th Nuclear Isomeric Transition

NASA Astrophysics Data System (ADS)

Jeet, Justin; Schneider, Christian; Sullivan, Scott T.; Rellergert, Wade G.; Mirzadeh, Saed; Cassanho, A.; Jenssen, H. P.; Tkalya, Eugene V.; Hudson, Eric R.

2015-06-01

We report the results of a direct search for the 229Th (Iπ=3 /2+←5 /2+ ) nuclear isomeric transition, performed by exposing 229Th -doped LiSrAlF6 crystals to tunable vacuum-ultraviolet synchrotron radiation and observing any resulting fluorescence. We also use existing nuclear physics data to establish a range of possible transition strengths for the isomeric transition. We find no evidence for the thorium nuclear transition between 7.3 eV and 8.8 eV with transition lifetime (1-2) s ≲τ ≲(2000 - 5600 ) s . This measurement excludes roughly half of the favored transition search area and can be used to direct future searches.

Results of a Direct Search Using Synchrotron Radiation for the Low-Energy Th 229 Nuclear Isomeric Transition

DOE PAGES

Jeet, Justin; Schneider, Christian; Sullivan, Scott T.; ...

2015-06-23

We report the results of a direct search for the 229Tn (I π = 3/2 + ← 5/2 +) nuclear isomeric transition, performed by exposing 229Tn-doped LiSrAlF 6 crystals to tunable vacuum-ultraviolet synchrotron radiation and observing any resulting fluorescence. We also use existing nuclear physics data to establish a range of possible transition strengths for the isomeric transition. We find no evidence for the thorium nuclear transition between 7.3 eV and 8.8 eV with transition lifetime (1–2) s≲τ≲ (2000-5600) s. Lastly, this measurement excludes roughly half of the favored transition search area and can be used to direct future searches.

Results of a Direct Search Using Synchrotron Radiation for the Low-Energy (229)Th Nuclear Isomeric Transition.

PubMed

Jeet, Justin; Schneider, Christian; Sullivan, Scott T; Rellergert, Wade G; Mirzadeh, Saed; Cassanho, A; Jenssen, H P; Tkalya, Eugene V; Hudson, Eric R

2015-06-26

We report the results of a direct search for the (229)Th (I(π)=3/2(+)←5/2(+)) nuclear isomeric transition, performed by exposing (229)Th-doped LiSrAlF(6) crystals to tunable vacuum-ultraviolet synchrotron radiation and observing any resulting fluorescence. We also use existing nuclear physics data to establish a range of possible transition strengths for the isomeric transition. We find no evidence for the thorium nuclear transition between 7.3 eV and 8.8 eV with transition lifetime (1-2) s≲τ≲(2000-5600)  s. This measurement excludes roughly half of the favored transition search area and can be used to direct future searches.

An epidemiological study of cutaneous leishmaniasis in Al-jabal Al-gharbi, Libya.

PubMed

Abdellatif, Manal Z M; El-Mabrouk, Khamis; Ewis, Ashraf A

2013-02-01

Cutaneous leishmaniasis (CL) is an endemic parasitic infection in the Mediterranean region, including Libya and its Al-jabal Al-gharbi province. We aimed at studying the occupational relevance as well as other epidemiological aspects of CL. We investigated 140 CL cases who attended at Gharyan outpatient polyclinic during a period of 6 months in 2009. CL infection was clinically diagnosed and confirmed by demonstration of Leishmania parasites on smears from lesions. Our findings showed that males were more affected than females (P=0.04), and people above 10-years were more affected than younger ones (P=0.0001). A significant percent of CL cases belonged to Al-Kawasem subprovince (P=0.0001). Farm-related activities were the most frequent occupations among CL cases (P=0.04). In addition to farm workers, housewives and students are at risk groups since they are engaged at farm activities. Moreover, those who have occupations that require staying outdoors for a part of night, e.g., policemen, are also at risk. Compared to children, adult CL patients had multiple lesions (P=0.001) that were more prevalent in their upper and lower extremities than the face (P=0.0001). We conclude that CL is a major health problem in Al-jabal Al-gharbi province of Libya. The presence of rodents and sandflies makes it a suitable environment for Leishmania to spread in an endemic epidemiological pattern. Being engaged in farming activities or outdoor occupations increases the risk of infection. Various clinical patterns of CL suggest the presence of more than 1 species of Leishmania at Al-jabal Al-gharbi province. We propose that the 2 species responsible for CL in this area are L. major and L. tropica. Further investigations to identify the leishmanial species responsible for CL at Al-jabal Al-gharbi together with adoption of preventive and control programs are needed.

An Epidemiological Study of Cutaneous Leishmaniasis in Al-Jabal Al-Gharbi, Libya

PubMed Central

Abdellatif, Manal Z. M.; El-Mabrouk, Khamis

2013-01-01

Cutaneous leishmaniasis (CL) is an endemic parasitic infection in the Mediterranean region, including Libya and its Al-jabal Al-gharbi province. We aimed at studying the occupational relevance as well as other epidemiological aspects of CL. We investigated 140 CL cases who attended at Gharyan outpatient polyclinic during a period of 6 months in 2009. CL infection was clinically diagnosed and confirmed by demonstration of Leishmania parasites on smears from lesions. Our findings showed that males were more affected than females (P=0.04), and people above 10-years were more affected than younger ones (P=0.0001). A significant percent of CL cases belonged to Al-Kawasem subprovince (P=0.0001). Farm-related activities were the most frequent occupations among CL cases (P=0.04). In addition to farm workers, housewives and students are at risk groups since they are engaged at farm activities. Moreover, those who have occupations that require staying outdoors for a part of night, e.g., policemen, are also at risk. Compared to children, adult CL patients had multiple lesions (P=0.001) that were more prevalent in their upper and lower extremities than the face (P=0.0001). We conclude that CL is a major health problem in Al-jabal Al-gharbi province of Libya. The presence of rodents and sandflies makes it a suitable environment for Leishmania to spread in an endemic epidemiological pattern. Being engaged in farming activities or outdoor occupations increases the risk of infection. Various clinical patterns of CL suggest the presence of more than 1 species of Leishmania at Al-jabal Al-gharbi province. We propose that the 2 species responsible for CL in this area are L. major and L. tropica. Further investigations to identify the leishmanial species responsible for CL at Al-jabal Al-gharbi together with adoption of preventive and control programs are needed. PMID:23467624

Validation of a [Al18F]PSMA-11 preparation for clinical applications.

PubMed

Al-Momani, Ehab; Israel, Ina; Samnick, Samuel

2017-12-01

Imaging prostate-specific membrane antigen (PSMA) using positron emission tomography (PET) has been presented so far as the most sensitive and specific with regard to prostate cancer detection, in particular in high-risk prostate cancer patients. Currently, it mainly features Gallium-68 ( 68 Ga) labeled PSMA ligands, notably [ 68 Ga]Glu-urea-Lys(Ahx)-HBED-CC ([ 68 Ga]-PSMA-11) and [ 68 Ga]DOTAGA-FFK (Sub-KuE termed ([ 68 Ga]PSMA-I&T). However, 68 Ga has several shortcomings as radionuclide including a short half-life and non-ideal energies. This has motivated consideration of 18 F-labeled analogues for PET imaging of prostate cancer. Here, we describe a simple synthesis and validation of a fluorine-18 labeled Glu-urea-Lys(Ahx)-HBED-CC ([Al 18 F]PSMA-11) for nuclear medicine applications. An efficient method for preparation of [Al 18 F]PSMA-11 was developed and validated (according to Pharm Eur) for routinely clinical applications. [Al 18 F]PSMA-11 was reproducibly obtained in radiochemical yields of 84 ± 6% (n = 15) and > 98% radiochemical purity using an improved one-step radiofluorination in aqueous solution. The total (production/preparation) time, including purification, pharmacological formulation of the isolated product and the quality control of the injectable solution was less than 60min. The [Al 18 F]PSMA-11 was stable over 4h in 1% EtOH/saline selected as injection solution. The solution was sterile, non-pyrogenic and ready for clinical applications after sterile filtration through a 0.22µm membrane filter under sterile conditions. In addition, [Al 18 F]PSMA-11 exhibited higher uptake and retention in PMSA-expressing LNCap prostate cells as compared to its clinically established 68 Ga-labeled analogues [ 68 Ga]PSMA-11 and [ 68 Ga]PSMA-I&T as well as to [ 68 Ga]NOTA-Bn-PSMA. The simple and fast preparation of [Al 18 F]PSMA-11 combined with its favorable pharmacological properties warrant its translation to a clinical setting. The facile and high

Formation of epitaxial Al 2O 3/NiAl(1 1 0) films: aluminium deposition

NASA Astrophysics Data System (ADS)

Lykhach, Y.; Moroz, V.; Yoshitake, M.

2005-02-01

Structure of epitaxial Al 2O 3 layers formed on NiAl(1 1 0) substrates has been studied by means of reflection high-energy electron diffraction (RHEED). The elucidated structure was compared to the model suggested for 0.5 nm-thick Al 2O 3 layers [K. Müller, H. Lindner, D.M. Zehner, G. Ownby, Verh. Dtsch. Phys. Ges. 25 (1990) 1130; R.M. Jaeger, H. Kuhlenbeck, H.J. Freund, Surf. Sci. 259 (1991) 235]. The stepwise growth of Al 2O 3 film, involving deposition and subsequent oxidation of aluminium onto epitaxial 0.5 nm-thick Al 2O 3 layers, has been investigated. Aluminium was deposited at room temperature, whereas its oxidation took place during annealing at 1070 K. The Al 2O 3 thickness was monitored by means of Auger electron spectroscopy (AES). It was found that Al 2O 3 layer follows the structure of 0.5 nm thick Al 2O 3 film, although a tilting of Al 2O 3(1 1 1) surface plane with respect to NiAl(1 1 0) surface appeared after Al deposition.

Amyotrophic lateral sclerosis (ALS)

MedlinePlus

Lou Gehrig disease; ALS; Upper and lower motor neuron disease; Motor neuron disease ... One out of 10 cases of ALS is due to a genetic defect. The cause is unknown in most other cases. In ALS, motor nerve cells (neurons) waste away ...

All About ALS

MedlinePlus

... by storm with videos of people pouring ice water on themselves for the Ice Bucket Challenge. The worldwide phenomenon raised awareness—and millions of research dollars—for a fatal disease called ALS. ALS ...

Oxidation behavior of Al/Cr coating on Ti2AlNb alloy at 900 °C

NASA Astrophysics Data System (ADS)

Yang, Zhengang; Liang, Wenping; Miao, Qiang; Chen, Bowen; Ding, Zheng; Roy, Nipon

2018-04-01

In this paper, the Al/Cr coating was fabricated on the surface of Ti2AlNb alloy via rf magnetron sputtering and double glow treatment to enhance oxidation resistance. The protective coating with an outer layer of Al and inner layer of Cr has great bonding strength due to the in-diffusion of Cr and the inter-diffusion between Al and Cr to form Al-Cr alloyed layer which has great hardness. Acoustic emission curve which was detected via WS-2005 scratch tester indicates the bonding strength between Al/Cr coating and substrate is great. Morphology of Ti2AlNb alloy with Al/Cr coating after scratch test shows that the scratch is smooth without disbanding, and the depth and breadth of scratch are changed uniformly. The mass change was reduced after oxidation test due to the Al/Cr protective coating. Isothermal oxidation test at 900 °C was researched. Results indicate that Al/Cr coating provided oxidation resistance of Ti2AlNb alloy with prolonged air exposure at 900 °C. Al2O3 was detected by XRD patterns and SEM images, and was formed on the surface of Ti2AlNb alloy to protect substrate during oxidation test. A certain content of Cr is beneficial for the formation of Al2O3. Besides, Cr2O3 was produced under Al2O3 by outward diffusion of Cr to protect substrate sequentially, no cracks were discovered on Al/Cr protective coating. The process of Ti outward diffusion into surface was suppressive due to integration of Cr-Ti and Al-Ti intermetallics. A steady, adherent and continuous coated layer of Al/Cr on Ti2AlNb alloy increases oxidation resistance.

Motor neuron differentiation of iPSCs obtained from peripheral blood of a mutant TARDBP ALS patient.

PubMed

Bossolasco, Patrizia; Sassone, Francesca; Gumina, Valentina; Peverelli, Silvia; Garzo, Maria; Silani, Vincenzo

2018-05-17

Amyotrophic lateral sclerosis (ALS) is a severe neurodegenerative disease, mainly affecting the motor neurons (MNs) and without effective therapy. Drug screening is hampered by the lack of satisfactory experimental and pre-clinical models. Induced pluripotent stem cells (iPSCs) could help to define disease mechanisms and therapeutic strategies as they could be differentiated into MNs, otherwise inaccessible from living humans. In this study, given the seminal role of TDP-43 in ALS pathophysiology, MNs were obtained from peripheral blood mononuclear cells-derived iPSCs of an ALS patient carrying a p.A382T TARDBP mutation and a healthy donor. Venous samples were preferred to fibroblasts for their ease of collection and no requirement for time consuming extended cultures before experimentation. iPSCs were characterized for expression of specific markers, spontaneously differentiated into primary germ layers and, finally, into MNs. No differences were observed between the mutated ALS patient and the control MNs with most of the cells displaying a nuclear localization of the TDP-43 protein. In conclusion, we here demonstrated for the first time that human TARDBP mutated MNs can be successfully obtained exploiting the reprogramming and differentiation ability of peripheral blood cells, an easily accessible source from any patient. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

Elastocaloric effect in CuAlZn and CuAlMn shape memory alloys under compression

PubMed Central

Qian, Suxin; Wang, Yi; Pillsbury, Thomas E.; Hada, Yoshiharu; Yamaguchi, Yuki; Fujimoto, Kenjiro; Hwang, Yunho; Radermacher, Reinhard; Cui, Jun; Yuki, Yoji; Toyotake, Koutaro; Takeuchi, Ichiro

2016-01-01

This paper reports the elastocaloric effect of two Cu-based shape memory alloys: Cu68Al16Zn16 (CuAlZn) and Cu73Al15Mn12 (CuAlMn), under compression at ambient temperature. The compression tests were conducted at two different rates to approach isothermal and adiabatic conditions. Upon unloading at a strain rate of 0.1 s−1 (adiabatic condition) from 4% strain, the highest adiabatic temperature changes (ΔTad) of 4.0 K for CuAlZn and 3.9 K for CuAlMn were obtained. The maximum stress and hysteresis at each strain were compared. The stress at the maximum recoverable strain of 4.0% for CuAlMn was 120 MPa, which is 70% smaller than that of CuAlZn. A smaller hysteresis for the CuAlMn alloy was also obtained, about 70% less compared with the CuAlZn alloy. The latent heat, determined by differential scanning calorimetry, was 4.3 J g−1 for the CuAlZn alloy and 5.0 J g−1 for the CuAlMn alloy. Potential coefficients of performance (COPmat) for these two alloys were calculated based on their physical properties of measured latent heat and hysteresis, and a COPmat of approximately 13.3 for CuAlMn was obtained. This article is part of the themed issue ‘Taking the temperature of phase transitions in cool materials’. PMID:27402936

Detection of surface deformation and ionospheric perturbation by the North Korea nuclear test

NASA Astrophysics Data System (ADS)

Park, S. C.; Lee, W. J.; Sohn, D. H.; Lee, D. K.; Jung, H. S.

2017-12-01

We used remote sensing data to detect the changes on surface and ionosphere due to the North Korea nuclear test. To analyze the surface deformation before and after the 6th North Korea (NK) nuclear test, we used Satellite Aperture Radar (SAR) images. It was reported that there were some surface deformation with about 10 cm by the 4th test (Wei, 2017) and the 5th test (Jo, 2017) using Interferometric SAR (InSAR) technique. However we could not obtain surface deformation by the 6th test using InSAR with Advanced Land Observation Satellite 2 (ALOS-2) data because of low coherence in the area close to the epicenter. Although the low coherence can be occurred due to several reasons, the main reason may be large deformation in this particular case. Therefore we applied pixel offset method to measure the amount of surface deformation in the area with low coherence. Pixel offset method calculates the deformation in the directions along track and Line-of-Sight (LOS) using cross correlation of intensity of two SAR images before and after the event for a pixel and is used frequently to obtain large deformation of glacier (e.g. Lee et al., 2015). Applying pixel offset method to the area of the 6th NK nuclear test, we obtained about 3 m surface deformation in maximum. It seems that the larger deformation occurs as the mountain slope is steeper.We then analyzed ionospheric perturbation using Global Navigation Satellite System (GNSS) data. If acoustic wave by a nuclear test goes up to the ionosphere and disturbs electron density, then the changes in slant total electron content (STEC) may be detected by GNSS satellites. STEC perturbation has been reported in the previous NK nuclear tests (e.g. Park et al., 2011). We analyzed the third order derivatives of STEC for 51 GNSS stations in South Korea and found that some perturbation were appeared at 4 stations about 20 40 minutes after the test.

Structural and compositional evolution of Al{sub 3}(Zr,Y) precipitates in Al-Zr-Y alloy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gao, Haiyan, E-mail: gaohaiyan@sjtu.edu.cn

Structural and compositional evolution of Al{sub 3}(Zr,Y) precipitates in aged Al-Zr-Y alloy was investigated through atom probe tomography (APT) and transmission electron microscope (TEM) analysis and first principles calculations. The results show that short-bar-shaped D0{sub 19}-Al{sub 3}Y with some Zr atoms dissolved in precipitated at the very beginning of decomposition and worked as heterogeneous nuclei for L1{sub 2}-Al{sub 3}Zr with spherical morphology after being aged at 400 °C for 2 h. Quasi-static coarsening happened as the aging treatment lasted from 2 h to 200 h. However, distribution of Zr and Y atoms in Al{sub 3}(Zr,Y) is nearly uniform and Al{submore » 3}(Zr,Y) do not have the typical “Al{sub 3}RE core-Al{sub 3}Zr shell” structure which observed in other RE containing Al-Zr-RE alloys with L1{sub 2}-Al{sub 3}RE as nuclei. First principles calculations revealed that binding energy between Y and Zr is strong during the growth of Al{sub 3}(Zr,Y), which led to the co-precipitation of Y and Zr atoms and attribute to the evolution of Al{sub 3}(Zr,Y). - Highlights: •Al{sub 3}Y precipitated firstly and then became nuclei for Al{sub 3}Zr during aging of Al-Zr-Y. •Al{sub 3}(Zr,Y) precipitates do not have the typical “Al{sub 3}Y core-Al{sub 3}Zr shell” structure. •Strong binding between Y and Zr led to the co-precipitation of Y and Zr atoms.« less

2nd Gen FeCrAl ODS Alloy Development For Accident-Tolerant Fuel Cladding

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dryepondt, Sebastien N.; Massey, Caleb P.; Edmondson, Philip D.

Extensive research at ORNL aims at developing advanced low-Cr high strength FeCrAl alloys for accident tolerant fuel cladding. One task focuses on the fabrication of new low Cr oxide dispersion strengthened (ODS) FeCrAl alloys. The first Fe-12Cr-5Al+Y 2O 3 (+ ZrO 2 or TiO 2) ODS alloys exhibited excellent tensile strength up to 800 C and good oxidation resistance in steam up to 1400 C, but very limited plastic deformation at temperature ranging from room to 800 C. To improve alloy ductility, several fabrication parameters were considered. New Fe-10-12Cr-6Al gas-atomized powders containing 0.15 to 0.5wt% Zr were procured and ballmore » milled for 10h, 20h or 40h with Y2O3. The resulting powder was then extruded at temperature ranging from 900 to 1050 C. Decreasing the ball milling time or increasing the extrusion temperature changed the alloy grain size leading to lower strength but enhanced ductility. Small variations of the Cr, Zr, O and N content did not seem to significantly impact the alloy tensile properties, and, overall, the 2nd gen ODS FeCrAl alloys showed significantly better ductility than the 1st gen alloys. Tube fabrication needed for fuel cladding will require cold or warm working associated with softening heat treatments, work was therefore initiated to assess the effect of these fabrications steps on the alloy microstructure and properties. This report has been submitted as fulfillment of milestone M3FT 16OR020202091 titled, Report on 2nd Gen FeCrAl ODS Alloy Development for the Department of Energy Office of Nuclear Energy, Advanced Fuel Campaign of the Fuel Cycle R&D program.« less

Revisiting Deng et al.'s Multiparty Quantum Secret Sharing Protocol

NASA Astrophysics Data System (ADS)

Hwang, Tzonelih; Hwang, Cheng-Chieh; Yang, Chun-Wei; Li, Chuan-Ming

2011-09-01

The multiparty quantum secret sharing protocol [Deng et al. in Chin. Phys. Lett. 23: 1084-1087, 2006] is revisited in this study. It is found that the performance of Deng et al.'s protocol can be much improved by using the techniques of block-transmission and decoy single photons. As a result, the qubit efficiency is improved 2.4 times and only one classical communication, a public discussion, and two quantum communications between each agent and the secret holder are needed rather than n classical communications, n public discussions, and 3n/2 quantum communications required in the original scheme.

Description and Comparison of Morphological Structures of the Eggs of Anopheles Hyrcanus Group and Related Species (Diptera: Culicidae) from the Republic of Korea

DTIC Science & Technology

2009-10-20

major vector of malaria in China ; however, its vectorial capacity is unknown in the ROK. The other remaining four Anopheles species are not considered to...morphometry and morphology of Anopheles aconitus Form B and C eggs under scanning electron microscope. Revista do Instituto de Medicina Tropical de Sao Paulo...and its genetic identity with An. (Ano.) anthropophagus from China (Diptera: Culicidae). Zootaxa, 378, 1–14. RUEDA ET AL.40 · Zootaxa 2268 © 2009

Nuclear Structure Aspects in Nuclear Astrophysics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Smith, Michael Scott

2006-12-01

Nuclear Astrophysics as a broad and diverse field of study can be viewed as a magnifier of the impact of microscopic processes on the evolution of macroscopic events. One of the primary goals in Nuclear Astrophysics is the understanding of the nucleosynthesis processes that take place in the cosmos and the simulation of the correlated stellar and explosive burning scenarios. These simulations are strongly dependent on the input from Nuclear Physics which sets the time scale for all stellar dynamic processes--from giga-years of stellar evolution to milliseconds of stellar explosions--and provides the basis for most of the signatures that wemore » have for the interpretation of these events--from stellar luminosities, elemental and isotopic abundances to neutrino flux from distant supernovae. The Nuclear Physics input comes through nuclear structure, low energy reaction rates, nuclear masses, and decay rates. There is a common perception that low energy reaction rates are the most important component of the required nuclear physics input; however, in this article we take a broader approach and present an overview of the close correlation between various nuclear structure aspects and their impact on nuclear astrophysics. We discuss the interplay between the weak and the strong forces on stellar time scales due to the limitations they provide for the evolution of slow and rapid burning processes. The effects of shell structure in nuclei on stellar burning processes as well as the impact of clustering in nuclei is outlined. Furthermore we illustrate the effects of the various nuclear structure aspects on the major nucleosynthesis processes that have been identified in the last few decades. We summarize and provide a coherent overview of the impact of all aspects of nuclear structure on nuclear astrophysics.« less

Nanoindentation investigation of heavy ion irradiated Ti 3(Si,Al)C 2

NASA Astrophysics Data System (ADS)

Liu, X. M.; Le Flem, M.; Béchade, J. L.; Monnet, I.

2010-06-01

Because of good damage tolerance, thermal stability and interesting mechanical properties, Ti 3SiC 2, belonging to M n+1AX n phases, has been considered as a potential candidate material for applications in the future Gas Fast nuclear Reactors (GFR) such as components of fuel cladding working between 500 °C and 800 °C. However, the outstanding mechanical properties of Ti 3SiC 2 related to a layered microstructure could be impacted by irradiation. In this work, high energy Kr and Xe ion irradiated Ti 3Si 0.95Al 0.05C 2 and Ti 3Si 0.90Al 0.10C 2 samples, provided by IMR Shenyang, Chinese Academy of Science, were characterized by nanoindentation technique. After irradiation at room temperature, an increase in hardness with irradiation dose was highlighted. Nevertheless, some damage tolerance remained because of preservation of the typical MAX layered structure. Irradiations at 300 °C and 500 °C lead to less significant increase suggesting irradiation defect annealing. A complete recovery of the properties at 800 °C seems to be obtained.

Fabrication of Al/Mg/Al Composites via Accumulative Roll Bonding and Their Mechanical Properties

PubMed Central

Nie, Jinfeng; Liu, Mingxing; Wang, Fang; Zhao, Yonghao; Li, Yusheng; Cao, Yang; Zhu, Yuntian

2016-01-01

Al(1060)/Mg(AZ31)/Al(1060) multilayered composite was successfully produced using an accumulative roll bonding (ARB) process for up to four cycles at an elevated temperature (400 °C). The microstructure evolution of the composites and the bonding characteristics at the interfaces between Al and Mg layers with increasing ARB cycles were characterized through optical microscopy, field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM). It was found that the grains of Al and Mg layers were significantly refined and Al3Mg2 and Al12 Mg17 intermetallic compound layers formed at the Al/Mg bonding interfaces. The strength increased gradually and the ultimate tensile strength (UTS) reached a maximum value of about 240 MPa at the third pass. Furthermore, the strengthening mechanism of the composite was analyzed based on the fracture morphologies. PMID:28774072

The nuclear arsenals and nuclear disarmament.

PubMed

Barnaby, F

1998-01-01

Current world stockpiles of nuclear weapons and the status of treaties for nuclear disarmament and the ultimate elimination of nuclear weapons are summarised. The need for including stockpiles of civil plutonium in a programme for ending production and disposing of fissile materials is emphasized, and the ultimate difficulty of disposing of the last few nuclear weapons discussed.

Suppression of gate leakage current in in-situ grown AlN/InAlN/AlN/GaN heterostructures based on the control of internal polarization fields

NASA Astrophysics Data System (ADS)

Kotani, Junji; Yamada, Atsushi; Ishiguro, Tetsuro; Yamaguchi, Hideshi; Nakamura, Norikazu

2017-03-01

This paper investigates the gate leakage characteristics of in-situ AlN capped InAlN/AlN/GaN heterostructures grown by metal-organic vapor phase epitaxy. It was revealed that the leakage characteristics of AlN capped InAlN/AlN/GaN heterostructures are strongly dependent on the growth temperature of the AlN cap. For an AlN capped structure with an AlN growth temperature of 740 °C, the leakage current even increased although there exists a large bandgap material on InAlN/AlN/GaN heterostructures. On the other hand, a large reduction of the gate leakage current by 4-5 orders of magnitudes was achieved with a very low AlN growth temperature of 430 °C. X-ray diffraction analysis of the AlN cap grown at 740 °C indicated that the AlN layer is tensile-strained. In contrast to this result, the amorphous structure was confirmed for the AlN cap grown at 430 °C by transmission electron microscopy. Furthermore, theoretical analysis based on one-dimensional band simulation was carried out, and the large increase in two-dimensional electron gas (2DEG) observed in Hall measurements was well reproduced by taking into account the spontaneous and piezo-electric polarization in the AlN layer grown at 740 °C. For the AlN capped structure grown at 430 °C, it is believed that the reduced polarization field in the AlN cap suppressed the penetration of 2DEG into the InAlN barrier layer, resulting in a small impact on 2DEG mobility and density. We believe that an in-situ grown AlN cap with a very low growth temperature of 430 °C is a promising candidate for high-frequency/high-power GaN-based devices with low gate leakage current.

Depolarization currents in Al 2O 3 and MgAl 2O 4 oxides

NASA Astrophysics Data System (ADS)

Carvalhaes, R. P. M.; Rocha, M. S.; de Souza, S. S.; Blak, A. R.

2004-06-01

In the present work, dipole defects in γ-irradiated and thermally treated samples of Al 2O 3 and MgAl 2O 4 oxides are investigated, applying the thermally stimulated depolarisation currents technique (TSDC). The TSDC spectra of MgAl 2O 4 doped with Fe 2+, Fe 3+, Co 2+, Cr 3+ and Mn 2+ show four bands at 130 K, 160 K, 250 K and 320 K, and the spectra of Al 2O 3 doped with Mg 2+, Cr 3+ and Fe 3+ show bands between 230 K and 260 K. It has been observed that the bands at 130 K, 160 K and 250 K in MgAl 2O 4 spinel and that the 230 K and 240 K bands in Al 2O 3 are related to dipole defects. The other bands are possibly related to different types of charge storage mechanisms (space-charge and interfacial polarisation) or deal with distributions in activation energies and/or in relaxation times. A thermal decrease of the TSDC bands for heat treatments above 1000 K has been observed. In MgAl 2O 4 spinel, the 250 K band could be recovered after γ-irradiation and the two dipole peaks in Al 2O 3 were partially recovered. Thermal treatments affect the dipole aggregation processes in both oxides. Optical absorption (AO) results indicate that the presence of bands of water molecules in the infrared region obstructs the appearance of the TSDC bands in both Al 2O 3 and MgAl 2O 4. The 250 K peak in MgAl 2O 4 was correlated to V-type centres and the 250 K peak in Al 2O 3 to a substitutional Mg 2+ ion near a trapped hole localised on an adjacent oxygen ion.

The growth of high-Al-content InAlGaN quaternary alloys by RF-MBE

NASA Astrophysics Data System (ADS)

Wang, B. Z.; Wang, X. L.; Wang, X. Y.; Guo, L. C.; Wang, X. H.; Xiao, H. L.; Liu, H. X.

2007-02-01

High-Al-content InxAlyGa1-x-yN (x = 1-10%, y = 34-45%) quaternary alloys were grown on sapphire by radio-frequency plasma-excited molecular beam epitaxy. Rutherford back-scattering spectrometry, high resolution x-ray diffraction and cathodoluminescence were used to characterize the InAlGaN alloys. The experimental results show that InAlGaN with an appropriate Al/In ratio (near 4.7, which is a lattice-match to the GaN under-layer) has better crystal and optical quality than the InAlGaN alloys whose Al/In ratios are far from 4.7. Some cracks and V-defects occur in high-Al/In-ratio InAlGaN alloys. In the CL image, the cracks and V-defect regions are the emission-enhanced regions.

Measurement of the spin temperature of optically cooled nuclei and GaAs hyperfine constants in GaAs/AlGaAs quantum dots

NASA Astrophysics Data System (ADS)

Chekhovich, E. A.; Ulhaq, A.; Zallo, E.; Ding, F.; Schmidt, O. G.; Skolnick, M. S.

2017-10-01

Deep cooling of electron and nuclear spins is equivalent to achieving polarization degrees close to 100% and is a key requirement in solid-state quantum information technologies. While polarization of individual nuclear spins in diamond and SiC (ref. ) reaches 99% and beyond, it has been limited to 50-65% for the nuclei in quantum dots. Theoretical models have attributed this limit to formation of coherent `dark' nuclear spin states but experimental verification is lacking, especially due to the poor accuracy of polarization degree measurements. Here we measure the nuclear polarization in GaAs/AlGaAs quantum dots with high accuracy using a new approach enabled by manipulation of the nuclear spin states with radiofrequency pulses. Polarizations up to 80% are observed--the highest reported so far for optical cooling in quantum dots. This value is still not limited by nuclear coherence effects. Instead we find that optically cooled nuclei are well described within a classical spin temperature framework. Our findings unlock a route for further progress towards quantum dot electron spin qubits where deep cooling of the mesoscopic nuclear spin ensemble is used to achieve long qubit coherence. Moreover, GaAs hyperfine material constants are measured here experimentally for the first time.

Preparation, deformation, and failure of functional Al-Sn and Al-Sn-Pb nanocrystalline alloys

NASA Astrophysics Data System (ADS)

Noskova, N. I.; Vil'Danova, N. F.; Filippov, Yu. I.; Churbaev, R. V.; Pereturina, I. A.; Korshunov, L. G.; Korznikov, A. V.

2006-12-01

Changes in the structure, hardness, mechanical properties, and friction coefficient of Al-30% Sn, Al-15% Sn-25% Pb, and Al-5% Sn-35% Pb (wt %) alloys subjected to severe plastic deformation by equal-channel angular pressing (with a force of 40 tonne) and by shear at a pressure of 5 GPa have been studied. The transition into the nanocrystalline state was shown to occur at different degrees of plastic deformation. The hardness exhibits nonmonotonic variations, namely, first it increases and subsequently decreases. The friction coefficient of the Al-30% Sn, Al-15% Sn-25% Pb, and Al-5% Sn-35% Pb alloys quenched from the melt was found to be 0.33; the friction coefficients of these alloys in the submicrocrystalline state (after equal-channel angular pressing) equal 0.24, 0.32, and 0.35, respectively. The effect of disintegration into nano-sized powders was found to occur in the Al-15% Sn-25% Pb, and Al-5% Sn-35% Pb alloys after severe plastic deformation to ɛ = 6.4 and subsequent short-time holding.

Temperature dependence of the dielectric response of anodized Al-Al2O3-metal capacitors

NASA Astrophysics Data System (ADS)

Hickmott, T. W.

2003-03-01

The temperature dependence of capacitance, CM, and conductance, GM, of Al-Al2O3-metal capacitors with Cu, Ag, and Au electrodes has been measured between 100 and 340 K at seven frequencies between 10 kHz and 1 MHz. Al2O3 films between 15 and 64 nm thick were formed by anodizing evaporated Al films in borate-glycol or borate-H2O electrolyte. The interface capacitance at the Al2O3-metal interface, CI, which is in series with the capacitance CD due to the Al2O3 dielectric, is determined from plots of 1/CM versus insulator thickness. CI is not fixed for a given metal-insulator interface but depends on the vacuum system used to deposit the metal electrode. CI is nearly temperature independent. When CI is taken into account the dielectric constant of Al2O3 determined from capacitance measurements is ˜8.3 at 295 K. The dielectric constant does not depend on anodizing electrolyte, insulator thickness, metal electrode, deposition conditions for the metal electrode or measurement frequency. By contrast, GM of Al-Al2O3-metal capacitors depends on both the deposition conditions of the metal and on the metal. For Al-Al2O3-Cu capacitors, GM is larger for capacitors with large values of 1/CI that result when Cu is evaporated in an oil-pumped vacuum system. For Al-Al2O3-Ag capacitors, GM does not depend on the Ag deposition conditions.

From Snow to Hill to ALS: An epidemiological odyssey in search of ALS causation.

PubMed

Armon, Carmel

2018-05-21

Establishing mechanisms of disease causation in neurodegenerative diseases has long seemed to be beyond the pale of traditional epidemiological tools. Establishing a plausible mechanism for initiation of amyotrophic lateral sclerosis (ALS) has appeared a particularly elusive goal. This review shows that a likely mechanism for ALS initiation may be inferred by applying classical methods of epidemiological inference. Advances in characterizing the biology of ALS suggest that most cases of ALS are cortically-generated, part of the ALS-FTD spectrum, with focal onset and spread by contiguity within the motor super-network. Evidence-based methods identified the most credible exogenous risk factor - smoking. AB Hill's nine viewpoints to inferring causation from association were invoked. The most likely mechanism consistent with smoking being a risk factor for ALS was inferred: cumulative DNA damage, akin to cumulative somatic mutations in carcinogenesis. Focal onset supports the concept that these changes, occurring in a single cell, may trigger the cascade leading to clinical ALS. The plausibility of this mechanism was affirmed by its coherence/consistency with other observations in sporadic, familial and western Pacific ALS. Application of traditional epidemiological reasoning suggests that cumulative DNA damage may contribute to disease onset in ALS. Copyright © 2018 Elsevier B.V. All rights reserved.

Polarization and Fowler-Nordheim tunneling in anodized Al-Al2O3-Au diodes

NASA Astrophysics Data System (ADS)

Hickmott, T. W.

2000-06-01

Polarization in anodic Al2O3 films is measured by using quasi-dc current-voltage (I-V) curves of Al-Al2O3-Au diodes. A reproducible polarization state is established by applying a negative voltage to the Au electrode of a rectifying Al-Al2O3-Au diode. The difference between subsequent I-V curves with Au positive is a measure of polarization in the sample. The magnitude of polarization charge in Al2O3 depends on the anodizing electrolyte. Al2O3 films formed in H2O-based electrolytes have approximately ten times the polarization charge of Al2O3 films formed in ethylene glycol-based electrolyte. Anodizing conditions that produce greater polarizing charge in anodic Al2O3 result in voltage-time curves during anodization under galvanostatic conditions that are nonlinear. Anodic films with greater polarizing charge also have a greater apparent interface capacitance which is independent of Al2O3 thickness. I-V curves of Al-Al2O3-Au diodes for increasing voltage are dominated by polarization. I-V curves for decreasing voltage are reproducible and parallel but depend on the maximum current and voltage reached during the measurement. There is no single current corresponding to a given voltage. I-V curves for decreasing voltage are analyzed assuming that the conduction mechanism is Fowler-Nordheim (FN) tunneling. There is a qualitative difference between the FN tunneling parameters for Al2O3 films formed in H2O-based electrolytes and those formed in ethylene glycol-based electrolyte. For the former the value of the exponential term in the FN analysis increases as the value of maximum voltage and current in an I-V characteristic increases, while the value of the pre-exponential term is nearly constant. For the latter, the exponential term is nearly constant as maximum voltage and current increase, but the pre-exponential term decreases by about 5 decades. Thus polarization charge incorporated during formation of anodized Al2O3 strongly affects the formation of the insulating

CuAlO2 and CuAl2O4 thin films obtained by stacking Cu and Al films using physical vapor deposition

NASA Astrophysics Data System (ADS)

Castillo-Hernández, G.; Mayén-Hernández, S.; Castaño-Tostado, E.; DeMoure-Flores, F.; Campos-González, E.; Martínez-Alonso, C.; Santos-Cruz, J.

2018-06-01

CuAlO2 and CuAl2O4 thin films were synthesized by the deposition of the precursor metals using the physical vapor deposition technique and subsequent annealing. Annealing was carried out for 4-6 h in open and nitrogen atmospheres respectively at temperatures of 900-1000 °C with control of heating and cooling ramps. The band gap measurements ranged from 3.3 to 4.5 eV. Electrical properties were measured using the van der Pauw technique. The preferred orientations of CuAlO2 and CuAl2O4 were found to be along the (1 1 2) and (3 1 1) planes, respectively. The phase percentages were quantified using a Rietveld refinement simulation and the energy dispersive X-ray spectroscopy indicated that the composition is very close to the stoichiometry of CuAlO2 samples and with excess of aluminum and deficiency of copper for CuAl2O4 respectively. High resolution transmission electron microscopy identified the principal planes in CuAlO2 and in CuAl2O4. Higher purities were achieved in nitrogen atmosphere with the control of the cooling ramps.

Three-Dimensional FIB/EBSD Characterization of Irradiated HfAl3-Al Composite

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hua, Zilong; Guillen, Donna Post; Harris, William

2016-09-01

A thermal neutron absorbing material, comprised of 28.4 vol% HfAl3 in an Al matrix, was developed to serve as a conductively cooled thermal neutron filter to enable fast flux materials and fuels testing in a pressurized water reactor. In order to observe the microstructural change of the HfAl3-Al composite due to neutron irradiation, an EBSD-FIB characterization approach is developed and presented in this paper. Using the focused ion beam (FIB), the sample was fabricated to 25µm × 25µm × 20 µm and mounted on the grid. A series of operations were carried out repetitively on the sample top surface tomore » prepare it for scanning electron microscopy (SEM). First, a ~100-nm layer was removed by high voltage FIB milling. Then, several cleaning passes were performed on the newly exposed surface using low voltage FIB milling to improve the SEM image quality. Last, the surface was scanned by Electron Backscattering Diffraction (EBSD) to obtain the two-dimensional image. After 50 to 100 two-dimensional images were collected, the images were stacked to reconstruct a three-dimensional model using DREAM.3D software. Two such reconstructed three-dimensional models were obtained from samples of the original and post-irradiation HfAl3-Al composite respectively, from which the most significant microstructural change caused by neutron irradiation apparently is the size reduction of both HfAl3 and Al grains. The possible reason is the thermal expansion and related thermal strain from the thermal neutron absorption. This technique can be applied to three-dimensional microstructure characterization of irradiated materials.« less

The Genyornis Egg: Response to Miller et al.'s commentary on Grellet-Tinner et al., 2016

NASA Astrophysics Data System (ADS)

Grellet-Tinner, Gerald; Spooner, Nigel A.; Handley, Warren D.; Worthy, Trevor H.

2017-04-01

Williams (1981) and Williams and Rich (1991) attributed Australian Quaternary fossil eggshell that differed from that of emu Dromaius novaehollandiae to the extinct bird Genyornis newtoni without any osteological or embryonic support. Such association by proximity or abundance mirrors the case of the mistaken association of oviraptor eggs to Protoceratops in the 1920's by Andrews (Grellet-Tinner and Makovicky, 2006). No other candidate species was considered, and this attribution has been unchallenged and followed by everyone thereafter. Much research has been done on this Australian eggshell, with one result being that the extinction of the parent of this eggshell is the most well documented for a taxon in Australia (e.g., Miller et al., 1999, 2005). Grellet-Tinner et al. (2016) raised several problems with the identity of the eggshell Williams (1981) attributed to Genyornis newtoni and suggested that extinct megapodes of the genus Progura were the more likely layer of this eggshell type, therein referred to as ;putative Genyornis oological material; (PGOM). Miller et al. (2017) challenged our hypothesis stating that ;Based on the dimensions of the reconstructed Spooner Egg,Grellet-Tinner et al. (2016)argue that PGOM is too small for a bird with the body mass estimated for Genyornis (168-275 kg) … …[and] …. None of the additional PGOM observations reported byGrellet-Tinner et al. (2016)are inconsistent with a Genyornis parent;. Here we take the opportunity to respond to their critique, the basis of which resolves into a few points, which we address in turn.

The effects of cation–anion clustering on defect migration in MgAl 2O 4

DOE PAGES

Zamora, Richard J.; Voter, Arthur F.; Perez, Danny; ...

2016-06-28

Magnesium aluminate spinel (MgAl 2O 4), like many other ceramic materials, offers a range of technological applications, from nuclear reactor materials to military body armor. For many of these applications, it is critical to understand both the formation and evolution of lattice defects throughout the lifetime of the material. We use the Speculatively Parallel Temperature Accelerated Dynamics (SpecTAD) method to investigate the effects of di-vacancy and di-interstitial formation on the mobility of the component defects. From long-time trajectories of the state-to-state dynamics, we characterize the migration pathways of defect clusters, and calculate their self-diffusion constants across a range of temperatures.more » We find that the clustering of Al and O vacancies drastically reduces the mobility of both defects, while the clustering of Mg and O vacancies completely immobilizes them. For interstitials, we find that the clustering of Mg and O defects greatly reduces O interstitial mobility, but has only a weak effect on Mg. Lastly, these findings illuminate important new details regarding defect kinetics relevant to the application of MgAl 2O 4 in extreme environments.« less

High temperature oxidation resistance of magnetron-sputtered homogeneous CrAlON coatings on 430 steel

NASA Astrophysics Data System (ADS)

Garratt, E.; Wickey, K. J.; Nandasiri, M. I.; Moore, A.; AlFaify, S.; Gao, X.; Kayani, A.; Smith, R. J.; Buchanan, T. L.; Priyantha, W.; Kopczyk, M.; Gannon, P. E.

2009-11-01

The requirements of low cost and high-temperature corrosion resistance for bipolar interconnect plates in solid oxide fuel cell stacks has directed attention to the use of metal plates with oxidation resistant coatings. We have investigated the performance of steel plates with homogenous coatings of CrAlON (oxynitrides). The coatings were deposited using RF magnetron sputtering, with Ar as a sputtering gas. Oxygen in these coatings was not intentionally added. Oxygen might have come through contaminated nitrogen gas bottle, leak in the chamber or from the partial pressure of water vapors. Nitrogen was added during the growth process to get oxynitride coating. The Cr/Al composition ratio in the coatings was varied in a combinatorial approach. The coatings were subsequently annealed in air for up to 25 hours at 800 oC. The composition of the coated plates and the rate of oxidation were characterized using Rutherford backscattering (RBS) and nuclear reaction analysis (NRA). Surface characterization was carried out using Atomic Force Microscopy (AFM) and surfaces of the coatings were found smooth on submicron scale. From our results, we conclude that Al rich coatings are more susceptible to oxidation than Cr rich coatings.

Mowafak Al-Jassim | NREL

Science.gov Websites

Mowafak Al-Jassim Photo of Mowafak Al-Jassim Mowafak Al-Jassim Group Research Manager III-Materials researcher and advancing to a principal scientist and a technical manager. His research group has contributed numerous international conferences. Research Interests His research interests include the multiscale

Data supporting Al-Abed et al., Environ. Sci.: Nano, 2016,

EPA Pesticide Factsheets

Data files representing each of the Figures and Tables published in Al-Abed et al., Environ. Sci.: Nano, 2016,3, 593. The data file names identify the Figure or Table and each file contains an internal set of data definitionsThis dataset is associated with the following publication:Al-Abed, S.R., J. Virkutyte, J. Ortenzio , R.M. McCarrick, L. Degn, R. Zucker , N. Coates , K. Cleveland, H. Ma, S. Diamond, K. Dreher , and W. Boyes. Environmental aging alters AI(OH)3 coating of TiO2 nanoparticles enhancing their photocatalytic and phototoxicity activities. Environmental Science: Nano. RSC Publishing, Cambridge, UK, N/A, (2016).

The deuteron-radius puzzle is alive: A new analysis of nuclear structure uncertainties

NASA Astrophysics Data System (ADS)

Hernandez, O. J.; Ekström, A.; Nevo Dinur, N.; Ji, C.; Bacca, S.; Barnea, N.

2018-03-01

To shed light on the deuteron radius puzzle we analyze the theoretical uncertainties of the nuclear structure corrections to the Lamb shift in muonic deuterium. We find that the discrepancy between the calculated two-photon exchange correction and the corresponding experimentally inferred value by Pohl et al. [1] remain. The present result is consistent with our previous estimate, although the discrepancy is reduced from 2.6 σ to about 2 σ. The error analysis includes statistic as well as systematic uncertainties stemming from the use of nucleon-nucleon interactions derived from chiral effective field theory at various orders. We therefore conclude that nuclear theory uncertainty is more likely not the source of the discrepancy.

Two-Phase (TiAl+TiCrAl) Coating Alloys for Titanium Aluminides

NASA Technical Reports Server (NTRS)

Brady, Michael P. (Inventor); Smialek, James L. (Inventor); Brindley, William J. (Inventor)

1998-01-01

A coating for protecting titanium aluminide alloys, including the TiAl gamma + Ti3Al (alpha(sub 2)) class, from oxidative attack and interstitial embrittlement at temperatures up to at least 1000 C. is disclosed. This protective coating consists essentially of titanium, aluminum. and chromium in the following approximate atomic ratio: Ti(41.5-34.5)Al(49-53)Cr(9.5-12.5)

Al Qaeda in the Arabian Peninsula (AQAP): An Al Qaeda Affiliate Case Study

DTIC Science & Technology

2017-10-01

Underwear Bombing ” and an unsuccessful 2010 plan to put parcel bombs on U.S.-bound airplanes. AQAP also seeks to inspire “lone jihad” attacks in the... bomb -maker,5 and Sudanese national Ibrahim al-Qosi, a former bookkeeper for Osama Bin Laden.6 Below the emir are regional commanders and heads of...5 “Profile: Al-Qaeda ‘ Bomb Maker’ Ibrahim al-Asiri,” BBC News, July 4, 2014, http://www.bbc.com/news/world-middle-east-11662143. See also al-Asiri

Versatile Oxide Films Protect FeCrAl Alloys Under Normal Operation and Accident Conditions in Light Water Power Reactors