Molecular imaging of inflammation in the ApoE -/- mouse model of atherosclerosis with IodoDPA

International Nuclear Information System (INIS)

Foss, Catherine A.; Bedja, Djahida; Mease, Ronnie C.; Wang, Haofan; Kass, David A.; Chatterjee, Subroto; Pomper, Martin G.

2015-01-01

Background: Atherosclerosis is a common and serious vascular disease predisposing individuals to myocardial infarction and stroke. Intravascular plaques, the pathologic lesions of atherosclerosis, are largely composed of cholesterol-laden luminal macrophage-rich infiltrates within a fibrous cap. The ability to detect those macrophages non-invasively within the aorta, carotid artery and other vessels would allow physicians to determine plaque burden, aiding management of patients with atherosclerosis. Methods and results: We previously developed a low-molecular-weight imaging agent, [ 125 I]iodo-DPA-713 (iodoDPA), which selectively targets macrophages. Here we use it to detect both intravascular macrophages and macrophage infiltrates within the myocardium in the ApoE -/- mouse model of atherosclerosis using single photon emission computed tomography (SPECT). SPECT data were confirmed by echocardiography, near-infrared fluorescence imaging and histology. SPECT images showed focal uptake of radiotracer at the aortic root in all ApoE -/- mice, while the age-matched controls were nearly devoid of radiotracer uptake. Focal radiotracer uptake along the descending aorta and within the myocardium was also observed in affected animals. Conclusions: IodoDPA is a promising new imaging agent for atherosclerosis, with specificity for the macrophage component of the lesions involved. - Highlights: • [ 125 I]iodoDPA SPECT detects atherosclerotic plaques in ApoE -/- mice with high contrast. • Plaques are detected in ApoE -/- mice regardless of diet with iodoDPA. • iodoDPA has very low uptake in healthy tissue including healthy TSPO + tissues at 24 h

DOE contractor vulnerability analysis: DPA or MAIT

International Nuclear Information System (INIS)

Six, D.E.; Nichols, D.H.

1980-01-01

Two vulnerability analysis techniques, Diversion Path Analysis (DPA) and Matrix Analysis of the Insider Threat (MAIT), were applied by EG and G Idaho, Inc. Safeguards and Security to the same item accountable SNM storage area at INEL. Technical and cost data for each methodology were collected and compared. A recommendation that MAIT be utilized for future vulnerability analyses of item accountable SNM storage and use areas operated by EG and G Idaho for DOE-ID resulted. Unclassified results of the two techniques and MAIT/DPA technical and cost comparisons will be presented which show that MAIT can be used for vulnerability analyses to comply with Department of Energy (DOE) requirements

Molecular imaging of inflammation in the ApoE -/- mouse model of atherosclerosis with IodoDPA

Energy Technology Data Exchange (ETDEWEB)

Foss, Catherine A., E-mail: cfoss1@jhmi.edu [Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD 21287 (United States); Bedja, Djahida [Department of Medicine, Division of Cardiology, Johns Hopkins University School of Medicine, Baltimore, MD 21287 (United States); Faculty of Medicine and Health Sciences, Macquarie University, Sydney (Australia); Mease, Ronnie C.; Wang, Haofan [Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD 21287 (United States); Kass, David A. [Department of Medicine, Division of Cardiology, Johns Hopkins University School of Medicine, Baltimore, MD 21287 (United States); Chatterjee, Subroto [Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, MD 21287 (United States); Pomper, Martin G. [Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD 21287 (United States)

2015-05-22

Background: Atherosclerosis is a common and serious vascular disease predisposing individuals to myocardial infarction and stroke. Intravascular plaques, the pathologic lesions of atherosclerosis, are largely composed of cholesterol-laden luminal macrophage-rich infiltrates within a fibrous cap. The ability to detect those macrophages non-invasively within the aorta, carotid artery and other vessels would allow physicians to determine plaque burden, aiding management of patients with atherosclerosis. Methods and results: We previously developed a low-molecular-weight imaging agent, [{sup 125}I]iodo-DPA-713 (iodoDPA), which selectively targets macrophages. Here we use it to detect both intravascular macrophages and macrophage infiltrates within the myocardium in the ApoE -/- mouse model of atherosclerosis using single photon emission computed tomography (SPECT). SPECT data were confirmed by echocardiography, near-infrared fluorescence imaging and histology. SPECT images showed focal uptake of radiotracer at the aortic root in all ApoE -/- mice, while the age-matched controls were nearly devoid of radiotracer uptake. Focal radiotracer uptake along the descending aorta and within the myocardium was also observed in affected animals. Conclusions: IodoDPA is a promising new imaging agent for atherosclerosis, with specificity for the macrophage component of the lesions involved. - Highlights: • [{sup 125}I]iodoDPA SPECT detects atherosclerotic plaques in ApoE -/- mice with high contrast. • Plaques are detected in ApoE -/- mice regardless of diet with iodoDPA. • iodoDPA has very low uptake in healthy tissue including healthy TSPO + tissues at 24 h.

Relationship between swelling and irradiation creep in cold worked PCA stainless steel to 178 DPA at∼400 degrees C

International Nuclear Information System (INIS)

Toloczko, M.B.; Garner, F.A.

1993-01-01

At 178 dpa and ∼400 degrees C, the irradiation creep behavior of 20% cold-worked PCA has become dominated by the creep disappearance phenomenon. The total diametral deformation rate has reached the limiting value of 0.33%/dpa at the three highest stress levels. The stress-enhancement of swelling tends to camouflage the onset of creep disappearance, however

Extreme embrittlement of austenitic stainless steel irradiated to 75-81 dpa at 335-360{degrees}C

Energy Technology Data Exchange (ETDEWEB)

Porollo, S.I.; Vorobjev, A.N.; Konobeev, Yu.V. [Institute of Physics and Power Engineering, Obninsk (Russian Federation)] [and others

1997-04-01

It is generally accepted that void swelling of austenitic steels ceases below some temperature in the range 340-360{degrees}C, and exhibits relatively low swelling rates up to {approximately}400{degrees}C. This perception may not be correct at all irradiation conditions, however, since it was largely developed from data obtained at relatively high displacement rates in fast reactors whose inlet temperatures were in the range 360-370{degrees}C. There is an expectation, however, that the swelling regime can shift to lower temperatures at low displacement rates via the well-known {open_quotes}temperature shift{close_quotes} phenomenon. It is also known that the swelling rates at the lower end of the swelling regime increase continuously at a sluggish rate, never approaching the terminal 1%/dpa level within the duration of previous experiments. This paper presents the results of an experiment conducted in the BN-350 fast reactor in Kazakhstan that involved the irradiation of argon-pressurized thin-walled tubes (0-200 MPa hoop stress) constructed from Fe-16Cr-15Ni-3Mo-Nb stabilized steel in contact with the sodium coolant, which enters the reactor at {approx}270{degrees}C. Tubes in the annealed condition reached 75 dpa at 335{degrees}C, and another set in the 20% cold-worked condition reached 81 dpa at 360{degrees}C. Upon disassembly all tubes, except those in the stress-free condition, were found to have failed in an extremely brittle fashion. The stress-free tubes exhibited diameter changes that imply swelling levels ranging from 9 to 16%. It is expected that stress-enhancement of swelling induced even larger swelling levels in the stressed tubes.

Extreme embrittlement of austenitic stainless steel irradiated to 75-81 dpa at 335-360 degrees C

International Nuclear Information System (INIS)

Porollo, S.I.; Vorobjev, A.N.; Konobeev, Yu.V.

1997-01-01

It is generally accepted that void swelling of austenitic steels ceases below some temperature in the range 340-360 degrees C, and exhibits relatively low swelling rates up to ∼400 degrees C. This perception may not be correct at all irradiation conditions, however, since it was largely developed from data obtained at relatively high displacement rates in fast reactors whose inlet temperatures were in the range 360-370 degrees C. There is an expectation, however, that the swelling regime can shift to lower temperatures at low displacement rates via the well-known open-quotes temperature shiftclose quotes phenomenon. It is also known that the swelling rates at the lower end of the swelling regime increase continuously at a sluggish rate, never approaching the terminal 1%/dpa level within the duration of previous experiments. This paper presents the results of an experiment conducted in the BN-350 fast reactor in Kazakhstan that involved the irradiation of argon-pressurized thin-walled tubes (0-200 MPa hoop stress) constructed from Fe-16Cr-15Ni-3Mo-Nb stabilized steel in contact with the sodium coolant, which enters the reactor at ∼270 degrees C. Tubes in the annealed condition reached 75 dpa at 335 degrees C, and another set in the 20% cold-worked condition reached 81 dpa at 360 degrees C. Upon disassembly all tubes, except those in the stress-free condition, were found to have failed in an extremely brittle fashion. The stress-free tubes exhibited diameter changes that imply swelling levels ranging from 9 to 16%. It is expected that stress-enhancement of swelling induced even larger swelling levels in the stressed tubes

Extreme embrittlement of austenitic stainless steel irradiated to 75--81 dpa at 335--360 C

International Nuclear Information System (INIS)

Porollo, S.I.; Vorobjev, A.N.; Konobeev, Yu.V.; Garner, F.A.

1998-01-01

This paper presents the results of an experiment conducted in the BN-350 fast reactor in Kazakhstan that involved the irradiation of argon-pressurized thin-walled tubes (0--2000 MPa hoop stress) constructed from Fe-16Cr-15Ni-3Mo-Nb stabilized steel in contact with the sodium coolant, which enters the reactor at ∼270 C. Tubes in the annealed condition reached 75 dpa at 335 C, and another set in the 20% cold-worked condition reached 81 dpa at 360 C. Upon disassembly all tubes, except those in the stress-free condition, were found to have failed in an extremely brittle fashion. The stress-free tubes exhibited diameter changes that imply swelling levels ranging from 9 to 16%. It is expected that stress-enhancement of swelling induced even larger swelling levels in the stressed tubes. The embrittlement is explained in terms of the sensitivity of the swelling regime to displacement rate and the large, unprecedented levels of swelling reached at 335--360 C at these high neutron fluences. The failure mechanism appears to be identical to that observed at similar swelling levels in other austenitic steels irradiated in US fast reactors at 400--425 C, whereby stress-concentration between voids and nickel segregation at void surfaces predisposes the steel to an epsilon martensite transformation followed by formation of alpha martensite at crack tips. The very slow strain rate inherent in such creep tests and the relatively high helium levels may also contribute to the failure

Quantitative Trait Locus and Brain Expression of HLA-DPA1 Offers Evidence of Shared Immune Alterations in Psychiatric Disorders

Directory of Open Access Journals (Sweden)

Ling Z. Morgan

2016-03-01

Full Text Available Genome-wide association studies of schizophrenia encompassing the major histocompatibility locus (MHC were highly significant following genome-wide correction. This broad region implicates many genes including the MHC complex class II. Within this interval we examined the expression of two MHC II genes (HLA-DPA1 and HLA-DRB1 in brain from individual subjects with schizophrenia (SZ, bipolar disorder (BD, major depressive disorder (MDD, and controls by differential gene expression methods. A third MHC II mRNA, CD74, was studied outside of the MHC II locus, as it interacts within the same immune complex. Exon microarrays were performed in anterior cingulate cortex (ACC in BD compared to controls, and both HLA-DPA1 and CD74 were decreased in expression in BD. The expression of HLA-DPA1 and CD74 were both reduced in hippocampus, amygdala, and dorsolateral prefrontal cortex regions in SZ and BD compared to controls by specific qPCR assay. We found several novel HLA-DPA1 mRNA variants spanning HLA-DPA1 exons 2-3-4 as suggested by exon microarrays. The intronic rs9277341 SNP was a significant cis expression quantitative trait locus (eQTL that was associated with the total expression of HLA-DPA1 in five brain regions. A biomarker study of MHC II mRNAs was conducted in SZ, BD, MDD, and control lymphoblastic cell lines (LCL by qPCR assay of 87 subjects. There was significantly decreased expression of HLA-DPA1 and CD74 in BD, and trends for reductions in SZ in LCLs. The discovery of multiple splicing variants in brain for HLA-DPA1 is important as the HLA-DPA1 gene is highly conserved, there are no reported splicing variants, and the functions in brain are unknown. Future work on the function and localization of MHC Class II proteins in brain will help to understand the role of alterations in neuropsychiatric disorders. The HLA-DPA1 eQTL is located within a large linkage disequilibrium block that has an irrefutable association with schizophrenia. Future

The co-evolution of microstructure features in self-ion irradiated HT9 at very high damage levels

Science.gov (United States)

Getto, Elizabeth Margaret

The objective of this study was to understand the co-evolution of microstructure features in self-ion irradiated HT9 at very high damage levels. HT9 (heat 84425) was pre-implanted with 10 atom parts per million helium and then irradiated with 5 MeV Fe++ in the temperature range of 440-480°C to 188 dpa. A damage dependence study from 75 to 650 dpa was performed at the peak swelling temperature of 460°C. The swelling, dislocation and precipitate evolution was determined using Analytic Electron Microscopes in both Conventional Transmission electron microscopy (CTEM) and Scanning Transmission Electron Microscopy (STEM) modes. Void swelling reached a nominally linear rate of 0.03%/dpa from 188 to 650 dpa at 460°C. G phase precipitates were observed by 75 dpa and grew linearly up to 650 dpa. M 2X was observed by 250 dpa and peaked in volume fraction at 450 dpa. Dislocation loop evolution was observed up to 650 dpa including a step change in diameter between 375 and 450 dpa; which correlated with nucleation and growth of M2X. The experimental results were interpreted using a rate theory model, the Radiation Induced Microstructure Evolution (RIME), in the damage range from 188 to 650 dpa. A simple system of voids and dislocations was modeled in which the dislocations measured from experiment were used as input, or the dislocations were allowed to evolve dynamically, resulting in swelling that was overestimated by 63% relative to that observed experimentally. G phase had limited effect on the void or dislocation behavior. The behavior of M2X within the microstructure was characterized as a direct effect as a coherent sink, and as an indirect effect in consuming carbon from the matrix, which had the largest impact on both void and dislocation behavior. A slowly monotonically increasing swelling rate was observed both experimentally and computationally, with swelling rates of ˜0.025%/dpa and ˜0.036%/dpa before and after 450 dpa. The agreement in void behavior between

Long-chain omega-3 fatty acids and the brain: a review of the independent and shared effects of EPA, DPA and DHA.

Science.gov (United States)

Dyall, Simon C

2015-01-01

Omega-3 polyunsaturated fatty acids (PUFAs) exhibit neuroprotective properties and represent a potential treatment for a variety of neurodegenerative and neurological disorders. However, traditionally there has been a lack of discrimination between the different omega-3 PUFAs and effects have been broadly accredited to the series as a whole. Evidence for unique effects of eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA) and more recently docosapentaenoic acid (DPA) is growing. For example, beneficial effects in mood disorders have more consistently been reported in clinical trials using EPA; whereas, with neurodegenerative conditions such as Alzheimer's disease, the focus has been on DHA. DHA is quantitatively the most important omega-3 PUFA in the brain, and consequently the most studied, whereas the availability of high purity DPA preparations has been extremely limited until recently, limiting research into its effects. However, there is now a growing body of evidence indicating both independent and shared effects of EPA, DPA and DHA. The purpose of this review is to highlight how a detailed understanding of these effects is essential to improving understanding of their therapeutic potential. The review begins with an overview of omega-3 PUFA biochemistry and metabolism, with particular focus on the central nervous system (CNS), where DHA has unique and indispensable roles in neuronal membranes with levels preserved by multiple mechanisms. This is followed by a review of the different enzyme-derived anti-inflammatory mediators produced from EPA, DPA and DHA. Lastly, the relative protective effects of EPA, DPA and DHA in normal brain aging and the most common neurodegenerative disorders are discussed. With a greater understanding of the individual roles of EPA, DPA and DHA in brain health and repair it is hoped that appropriate dietary recommendations can be established and therapeutic interventions can be more targeted and refined.

The Daily Physical Activity (DPA) policy in Ontario: is it working? an examination using accelerometry-measured physical activity data.

Science.gov (United States)

Stone, Michelle R; Faulkner, Guy E J; Zeglen-Hunt, Laura; Bonne, Jennifer Cowie

2012-01-01

In 2005, the Ontario Ministry of Education announced a policy requiring that all elementary students be provided with opportunities to participate in a minimum of 20 minutes of sustained moderate-to-vigorous physical activity (MVPA) each school day during instructional time. To the authors' knowledge, this policy has never been formally evaluated. In a form of natural experiment with Project BEAT, we explored within 16 Toronto District School Board schools the proportion of children who participate in DPA, and the proportion who achieve sustained MVPA within these sessions; these are the objectives of this article. Consent was given by 1027 parents/guardians for their children to participate (boys, n=478; girls, n=549). Physical activity (PA) was measured using accelerometry and classroom schedules collected to identify sessions of DPA. The frequency of DPA and number and duration of sustained bouts of MVPA (> or =5 min) were computed and explored relative to PA levels and health outcomes. Fewer than half of the participating children were provided with DPA every day and not a single child engaged in sustained MVPA for > or =20 minutes. On the more positive side, children who engaged in DPA every day were significantly more active than their peers. Those accumulating at least 1 bout of MVPA were more active and likely to meet PA guidelines, and fewer of these children were overweight. The majority of schools are not meeting the DPA policy. However, as the frequency and intensity of DPA increases, so do positive health outcomes. This paper provides supporting evidence that when this policy is implemented, the intended health benefits are achievable.

Tensile mechanical properties of a stainless steel irradiated up to 19 dpa in the Swiss spallation neutron source

Energy Technology Data Exchange (ETDEWEB)

Saito, Shigeru, E-mail: saito.shigeru@jaea.go.jp [JAEA, J-PARC Center, Tokai-mura, Ibaraki-ken 319-1195 (Japan); Kikuchi, Kenji [Ibaraki Univ., iFRC, Tokai-mura, Ibaraki-ken 319-1106 (Japan); Hamaguchi, Dai [JAEA, J-PARC Center, Tokai-mura, Ibaraki-ken 319-1195 (Japan); Usami, Kouji; Endo, Shinya; Ono, Katsuto; Matsui, Hiroki [JAEA, Dept. of Hot Laboratories, Tokai-mura, Ibaraki-ken 319-1195 (Japan); Kawai, Masayoshi [KEK, Tsukuba-shi, Ibaraki-ken 305-0801 (Japan); Dai, Yong [PSI, Spallation Source Division, Villigen PSI (Switzerland)

2012-12-15

To evaluate the lifetime of the beam window of an accelerator-driven transmutation system (ADS), post irradiation examination (PIE) of the STIP (SINQ target irradiation program, SINQ; Swiss spallation neutron source) specimens was carried out. The specimens tested in this study were made from the austenitic steel Japan primary candidate alloy (JPCA). The specimens were irradiated at SINQ Target 4 (STIP-II) with high-energy protons and spallation neutrons. The irradiation conditions were as follows: the proton energy was 580 MeV, irradiation temperatures ranged from 100 to 430 Degree-Sign C, and displacement damage levels ranged from 7.1 to 19.5 dpa. Tensile tests were performed in air at room temperature (RT), 250 Degree-Sign C and 350 Degree-Sign C. Fracture surface observation after the tests was done by Scanning electron microscope (SEM). Results of the tensile tests performed at R.T. showed the extra hardening of JPCA at higher dose compared to the fission neutron irradiated data. At the higher temperatures, 250 Degree-Sign C and 350 Degree-Sign C, the extra hardening was not observed. Degradation of ductility bottomed around 10 dpa, and specimens kept their ductility until 19.5 dpa. All specimens fractured in ductile manner.

Regulation of the Docosapentaenoic Acid/Docosahexaenoic Acid Ratio (DPA/DHA Ratio) in Schizochytrium limacinum B4D1.

Science.gov (United States)

Zhang, Ke; Li, Huidong; Chen, Wuxi; Zhao, Minli; Cui, Haiyang; Min, Qingsong; Wang, Haijun; Chen, Shulin; Li, Demao

2017-05-01

Docosapentaenoic acid/docosahexaenoic acid ratio (DPA/DHA ratio) in Schizochytrium was relatively stable. But ideally the ratio of DPA/DHA will vary according to the desired end use. This study reports several ways of modulating the DPA/DHA ratio. Incubation times changed the DPA/DHA ratio, and changes in this ratio were associated with the variations in the saturated fatty acid (SFAs) content. Propionic acid sharply increased the SFAs content in lipids, dramatically decreased the even-chain SFAs content, and reduced the DPA/DHA ratio. Pentanoic acid (C5:0) and heptanoic acid (C7:0) had similar effects as propionic acid, whereas butyric acid (C4:0), hexanoic acid (C6:0), and octanoic acid (C8:0) did not change the fatty acid profile and the DPA/DHA ratio. Transcription analyses show that β-oxidation might be responsible for this phenomenon. Iodoacetamide upregulated polyunsaturated fatty acid (PUFA) synthase genes, reduced the DHA content, and improved the DPA content, causing the DPA/DHA ratio to increase. These results present new insights into the regulation of the DPA/DHA ratio.

HLA DRB1*, DQB1*, DPA1* y DPB1* y su asociación con la patogénesis de las leucemias en población venezolana

Directory of Open Access Journals (Sweden)

Sergio E. Rivera-Pirela

2016-08-01

Full Text Available Background: The HLA complex is involved in the pathogenesis of leukemia. Objectives: The presence of class II HLA alleles DRB1 *, DQB1 *, DPA1 *, and DPB1 * was evaluated in 47 patients with acute lymphoblastic leukemia (ALL and 48 with chronic myeloid leukemia (CML for comparison with 48 healthy volunteers in Zulia, Venezuela, and to evaluate potential associations of HLA with leukemia. Methods: Low- and high-resolution PCR-SSP was used for class II HLA regions DRB1 *, DQB1 *, DPA1 *, and DPB1 * following the instructions of KIT Olerup SSP Genovision. Results: Alleles HLA-DRB1*14, especially DRB1*14:21, -DPA1*1:06, -DPA1*01:03,-DPA1*02:01, and the haplotypes HLA-DPA1*01:03-DPB1*04:01, DPA1*01:03-DPB1*02:01, DPA1*01:03-DPB1*99:01, -DRB1*14-DPA1*01:03, -DRB1*15-DPA1*01:03 were associated with CML (RR > 3; alleles HLA-DRB1*13, -DQB1*02, -DPA1*01:05, -DPA1*01:09 and the haplotypes HLA-DPA1*01:09-DPB1*02:01, DPA1*01:09-DPB1*04:01 were protective (RR < 1. Alleles HLA-DQB1*04, -DQB1*05, -DPA1*1:06, -DPA1*01:07, -DPA1*1:08 had a positive association with ALL. Alleles HLA-DPA1*01:09, -DPA1*02:01, -DPB1*02:01, -DPB1*03:01 and the haplotypes HLA-DPA1*01:03-DPB1*04:02, -DPA1*01:09-DPB1*02:01, -DPA1*01:09-DPB1*04:01, -DPA1*02:01-DPB1*04:02 were negatively associated. Conclusions: The absence of associations with HLA-DRB1 * region in ALL and other association patterns identified suggest marked differences in the pathogenesis of leukemia, which suggests possible deficiencies in antigen presentation for ALL or potential effects of molecular mimicry in CML.

Rate maximum calculation of Dpa in CNA-II pressure vessel

International Nuclear Information System (INIS)

Mascitti, J. A

2012-01-01

The maximum dpa rate was calculated for the reactor in the following state: fresh fuel, no Xenon, a Boron concentration of 15.3 ppm, critical state, its control rods in the criticality position, hot, at full power (2160 MW). It was determined that the maximum dpa rate under such conditions is 3.54(2)x10 12 s -1 and it is located in the positions corresponding to θ=210 o in the azimuthal direction, and z=20 cm and -60 cm respectively in the axial direction, considering the calculation mesh centered at half height of the fuel element (FE) active length. The dpa rate spectrum was determined as well as the contribution to it for 4 energy groups: a thermal group, two epithermal groups and a fast one. The maximum dpa rate considering the photo-neutrons production from (γ, n) reaction in the heavy water of coolant and moderator was 3.93(4)x10 12 s -1 that is 11% greater than the obtained without photo-neutrons. This verified significant difference between both cases, suggest that photo-neutrons in large heavy water reactors such as CNA-II should not be ignored. The maximum DPA rate in the first mm of the reactor pressure vessel was calculated too and it was obtained a value of 4.22(6)x10 12 s -1 . It should be added that the calculation was carried out with the reactor complete accurate model, with no approximations in spatial or energy variables. Each value has, between parentheses, a percentage relative error representing the statistical uncertainty due to the probabilistic Monte Carlo method used to estimate it. More representative values may be obtained with this method if equilibrium burn-up distribution is used (author)

Tunable paramagnetic relaxation enhancements by [Gd(DPA)3]3- for protein structure analysis

International Nuclear Information System (INIS)

Yagi, Hiromasa; Loscha, Karin V.; Su, Xun-Cheng; Stanton-Cook, Mitchell; Huber, Thomas; Otting, Gottfried

2010-01-01

Paramagnetic relaxation enhancements (PRE) present a powerful source of structural information in nuclear magnetic resonance (NMR) studies of proteins and protein-ligand complexes. In contrast to conventional PRE reagents that are covalently attached to the protein, the complex between gadolinium and three dipicolinic acid (DPA) molecules, [Gd(DPA) 3 ] 3- , can bind to proteins in a non-covalent yet site-specific manner. This offers straightforward access to PREs that can be scaled by using different ratios of [Gd(DPA) 3 ] 3- to protein, allowing quantitative distance measurements for nuclear spins within about 15 A of the Gd 3+ ion. Such data accurately define the metal position relative to the protein, greatly enhancing the interpretation of pseudocontact shifts induced by [Ln(DPA) 3 ] 3- complexes of paramagnetic lanthanide (Ln 3+ ) ions other than gadolinium. As an example we studied the quaternary structure of the homodimeric GCN4 leucine zipper.

Irradiation performance of oxide dispersion strengthened copper alloys to 150 dpa at 415 degree C

International Nuclear Information System (INIS)

Edwards, D.J.; Kumar, A.S.; Anderson, K.R.; Stubbins, J.F.; Garner, F.A.; Hamilton, M.L.

1991-11-01

Results have been obtained on the post-irradiation properties of various oxide dispersion strengthened copper alloys irradiated from 34 to 150 dpa at 415 degrees C in the Fast Flux Test Facility. The GlidCop alloys strengthened by Al 2 O 3 continue to outperform other alloys with respect to swelling resistance, and retention of both electrical conductivity and yield strength. Several castable ODS alloys and a Cr 2 O 3 -strengthened alloy show increasingly poor resistance to radiation, especially in their swelling behavior. A HfO 2 -strengthened alloy retains most of its strength and its electrical conductivity reaches a constant level after 50 dpa, but it exhibits a higher residual radioactivity

A study to compute integrated dpa for neutron and ion irradiation environments using SRIM-2013

Science.gov (United States)

Saha, Uttiyoarnab; Devan, K.; Ganesan, S.

2018-05-01

Displacements per atom (dpa), estimated based on the standard Norgett-Robinson-Torrens (NRT) model, is used for assessing radiation damage effects in fast reactor materials. A computer code CRaD has been indigenously developed towards establishing the infrastructure to perform improved radiation damage studies in Indian fast reactors. We propose a method for computing multigroup neutron NRT dpa cross sections based on SRIM-2013 simulations. In this method, for each neutron group, the recoil or primary knock-on atom (PKA) spectrum and its average energy are first estimated with CRaD code from ENDF/B-VII.1. This average PKA energy forms the input for SRIM simulation, wherein the recoil atom is taken as the incoming ion on the target. The NRT-dpa cross section of iron computed with "Quick" Kinchin-Pease (K-P) option of SRIM-2013 is found to agree within 10% with the standard NRT-dpa values, if damage energy from SRIM simulation is used. SRIM-2013 NRT-dpa cross sections applied to estimate the integrated dpa for Fe, Cr and Ni are in good agreement with established computer codes and data. A similar study carried out for polyatomic material, SiC, shows encouraging results. In this case, it is observed that the NRT approach with average lattice displacement energy of 25 eV coupled with the damage energies from the K-P option of SRIM-2013 gives reliable displacement cross sections and integrated dpa for various reactor spectra. The source term of neutron damage can be equivalently determined in the units of dpa by simulating self-ion bombardment. This shows that the information of primary recoils obtained from CRaD can be reliably applied to estimate the integrated dpa and damage assessment studies in accelerator-based self-ion irradiation experiments of structural materials. This study would help to advance the investigation of possible correlations between the damages induced by ions and reactor neutrons.

Monte Carlo study of electron irradiation effect on YBCO dpa profiles

International Nuclear Information System (INIS)

Pinnera, I.; Cruz, C.; Abreu, Y.; Leyva, A.; Van Espen, P.

2011-01-01

The Monte Carlo assisted Classical Method (MCCM) consists on a calculation procedure for determining the displacements per atom (dpa) distribution in solid materials. This algorithm allows studying the gamma and electron irradiation damage in different materials. It is based on the electrons elastic scattering classic theories and the use of Monte Carlo simulation for the physical processes involved. The present study deals with the Monte Carlo simulation of electron irradiation effects on YBa 2 Cu 3 O 7-x (YBCO) slabs using the MCNPX code system. Displacements per atom distributions are obtained through the MCCM for electron irradiation up to 10 MeV. In-depth dpa profiles for electrons and positrons are obtained and analyzed. Also, for each atomic species in the material, the dpa distributions are calculated. All the results are discussed in the present contribution. (Author)

PET imaging of neuroinflammation in a rat traumatic brain injury model with radiolabeled TSPO ligand DPA-714

Energy Technology Data Exchange (ETDEWEB)

Wang, Yu [Medical School of Southeast University, Jiangsu Key Laboratory of Molecular Imaging and Functional Imaging, Department of Radiology, Zhongda Hospital, Nanjing (China); National Institutes of Health - NIH, Laboratory of Molecular Imaging and Nanomedicine - LOMIN, National Institute of Biomedical Imaging and Bioengineering - NIBIB, Bethesda, MD (United States); Yue, Xuyi; Kiesewetter, Dale O.; Niu, Gang; Chen, Xiaoyuan [National Institutes of Health - NIH, Laboratory of Molecular Imaging and Nanomedicine - LOMIN, National Institute of Biomedical Imaging and Bioengineering - NIBIB, Bethesda, MD (United States); Teng, Gaojun [Medical School of Southeast University, Jiangsu Key Laboratory of Molecular Imaging and Functional Imaging, Department of Radiology, Zhongda Hospital, Nanjing (China)

2014-07-15

The inflammatory response in injured brain parenchyma after traumatic brain injury (TBI) is crucial in the pathological process. In order to follow microglia activation and neuroinflammation after TBI, we performed PET imaging in a rat model of TBI using {sup 18}F-labeled DPA-714, a ligand of the 18-kDa translocator protein (TSPO). TBI was induced in male SD rats by a controlled cortical impact. The success of the TBI model was confirmed by MRI. [{sup 18}F]DPA-714 was synthesized using a slightly modified TRACERLab FX-FN module and an automated procedure. In vivo PET imaging was performed at different time points after surgery using an Inveon small-animal PET scanner. The specificity of [{sup 18}F]DPA-714 was confirmed by a displacement study with an unlabeled competitive TSPO ligand, PK11195. Ex vivo autoradiography as well as immunofluorescence staining was carried out to confirm the in vivo PET results. Both in vivo T{sub 2}-weighted MR images and ex vivo TTC staining results revealed successful establishment of the TBI model. Compared with the sham-treated group, [{sup 18}F]DPA-714 uptake was significantly higher in the injured brain area on PET images. Increased lesion-to-normal ratios of [{sup 18}F]DPA-714 were observed in the brain of TBI rats on day 2 after surgery. Ratios peaked around day 6 (2.65 ± 0.36) and then decreased gradually to nearly normal levels on day 28. The displacement study using PK11195 confirmed the specific binding of [{sup 18}F]DPA-714 to TSPO. The results of ex vivo autoradiography were consistent with in vivo PET results. Immunofluorescence staining showed the time course of TSPO expression after TBI and the temporal and the spatial distribution of microglia in the damaged brain area. TSPO-targeted PET using [{sup 18}F]DPA-714 as the imaging probe can be used to dynamically monitor the inflammatory response after TBI in a noninvasive manner. This method will not only facilitate a better understanding of the inflammatory process

[18F]DPA-714: Direct comparison with [11C]PK11195 in a model of cerebral ischemia in rats

International Nuclear Information System (INIS)

Boutin, Herve; Prenant, Christian; Smigova, Alison; Cawthorne, Christopher; Brown, Gavin; Herholz, Karl; Maroy, Renaud; Galea, James; Greenhalgh, Andrew D.; Rothwell, Nancy J.; Julyan, Peter; Wilkinson, Shane M.; Banister, Samuel D.; Kassiou, Michael

2013-01-01

Neuro-inflammation is involved in several brain disorders and can be monitored through expression of the translocator protein 18 kDa (TSPO) on activated micro-glia. In recent years, several new PET radioligands for TSPO have been evaluated in disease models. [ 18 F]DPA-714 is a TSPO radiotracer with great promise; however results vary between different experimental models of neuro-inflammation. To further examine the potential of [ 18 F]DPA-714, it was compared directly to [ 11 C]PK11195 in experimental cerebral ischaemia in rats. Under anaesthesia, the middle cerebral artery of adult rats was occluded for 60 min using the filament model. Rats were allowed recovery for 5 to 7 days before one hour dynamic PET scans with [ 11 C]PK11195 and/or [ 18 F]DPA-714 under anaesthesia. Uptake of [ 11 C]PK11195 vs [ 18 F]DPA-714 in the ischemic lesion was similar (core/contralateral ratio: 2.8460.67 vs 2.2860.34 respectively), but severity of the brain ischemia and hence ligand uptake in the lesion appeared to vary greatly between animals scanned with [ 11 C]PK11195 or with [ 18 F]DPA-714. To solve this issue of inter-individual variability, we performed a direct comparison of [ 11 C]PK11195 and [ 18 F]DPA-714 by scanning the same animals sequentially with both tracers within 24 h. In this direct comparison, the core/contralateral ratio (3.3561.21 vs 4.6662.50 for [ 11 C]PK11195 vs [ 18 F]DPA-714 respectively) showed a significantly better signal-to-noise ratio (1.6 (1.3-1.9, 95%CI) fold by linear regression) for [ 18 F]DPA-714. In a clinically relevant model of neuro-inflammation, uptake for both radiotracers appeared to be similar at first, but a high variability was observed in our model. Therefore, to truly compare tracers in such models, we performed scans with both tracers in the same animals. By doing so, our result demonstrated that [ 18 F]DPA-714 displayed a higher signal-to-noise ratio than [ 11 C]PK11195. Our results suggest that, with the longer half-life of [ 18 F

[18F]DPA-714: direct comparison with [11C]PK11195 in a model of cerebral ischemia in rats.

Directory of Open Access Journals (Sweden)

Hervé Boutin

Full Text Available PURPOSE: Neuroinflammation is involved in several brain disorders and can be monitored through expression of the translocator protein 18 kDa (TSPO on activated microglia. In recent years, several new PET radioligands for TSPO have been evaluated in disease models. [(18F]DPA-714 is a TSPO radiotracer with great promise; however results vary between different experimental models of neuroinflammation. To further examine the potential of [(18F]DPA-714, it was compared directly to [(11C]PK11195 in experimental cerebral ischaemia in rats. METHODS: Under anaesthesia, the middle cerebral artery of adult rats was occluded for 60 min using the filament model. Rats were allowed recovery for 5 to 7 days before one hour dynamic PET scans with [(11C]PK11195 and/or [(18F]DPA-714 under anaesthesia. RESULTS: Uptake of [(11C]PK11195 vs [(18F]DPA-714 in the ischemic lesion was similar (core/contralateral ratio: 2.84±0.67 vs 2.28±0.34 respectively, but severity of the brain ischemia and hence ligand uptake in the lesion appeared to vary greatly between animals scanned with [(11C]PK11195 or with [(18F]DPA-714. To solve this issue of inter-individual variability, we performed a direct comparison of [(11C]PK11195 and [(18F]DPA-714 by scanning the same animals sequentially with both tracers within 24 h. In this direct comparison, the core/contralateral ratio (3.35±1.21 vs 4.66±2.50 for [(11C]PK11195 vs [(18F]DPA-714 respectively showed a significantly better signal-to-noise ratio (1.6 (1.3-1.9, 95%CI fold by linear regression for [(18F]DPA-714. CONCLUSIONS: In a clinically relevant model of neuroinflammation, uptake for both radiotracers appeared to be similar at first, but a high variability was observed in our model. Therefore, to truly compare tracers in such models, we performed scans with both tracers in the same animals. By doing so, our result demonstrated that [(18F]DPA-714 displayed a higher signal-to-noise ratio than [(11C]PK11195. Our results suggest

The independence of irradiation creep in austenitic alloys of displacement rate and helium to dpa ratio

Energy Technology Data Exchange (ETDEWEB)

Garner, F.A.; Toloczko, M.B. [Pacific Northwest National Lab., Richland, WA (United States); Grossbeck, M.L. [Oak Ridge National Lab., TN (United States)

1997-04-01

The majority of high fluence data on the void swelling and irradiation creep of austenitic steels were generated at relatively high displacement rates and relatively low helium/dpa levels that are not characteristic of the conditions anticipated in ITER and other anticipated fusion environments. After reanalyzing the available data, this paper shows that irradiation creep is not directly sensitive to either the helium/dpa ratio or the displacement rate, other than through their possible influence on void swelling, since one component of the irradiation creep rate varies with no correlation to the instantaneous swelling rate. Until recently, however, the non-swelling-related creep component was also thought to exhibit its own strong dependence on displacement rate, increasing at lower fluxes. This perception originally arose from the work of Lewthwaite and Mosedale at temperatures in the 270-350{degrees}C range. More recently this perception was thought to extend to higher irradiation temperatures. It now appears, however, that this interpretation is incorrect, and in fact the steady-state value of the non-swelling component of irradiation creep is actually insensitive to displacement rate. The perceived flux dependence appears to arise from a failure to properly interpret the impact of the transient regime of irradiation creep.

Influence of damage rate on physical and mechanical properties and swelling of 18Cr-9Ni austenitic steel in the range of 3.10-9 to 4.10-8 dpa/sec

International Nuclear Information System (INIS)

Shcherbakov, E.N.; Kozlov, A.V.; Yagovitin, R.I.; Evseev, M.V.; Kinev, E.A.; Isobe, Y.; Sagisaka, M.; Okita, T.; Sekimura, N.; Garner, F.

2007-01-01

Full text of publication follows: Whereas most data on radiation-induced changes in mechanical properties or dimensional stability needed for fusion - relevant dpa levels and dpa rates are generated at relatively high neutron flux in fast reactors, many fusion and fission components will operate at much lower dpa rates. Much less data are available from long-lived structural components operating at very low flux levels. In addition most published data were generated from relatively thin specimens (∼1-2 mm or less), while some actual fusion structural components can be on the order of 1-2 cm thick. In this study we have examined a 9 cm diameter pipe constructed from Fe-18Cr-9Ni steel analogous to AISI 304 that stayed outside the core of BN-600 for 22 years. The walls of the pipe were 2 cm thick and experienced temperatures in the range 370-375 deg. C. The walls were sectioned into 5 slices at a number of positions to yield doses in the range 1.5 to 22 dpa at 3 x 10 -9 to 4 x 10 -8 dpa/s. Changes in elastic moduli were studied using an ultrasonic technique and changes in electrical resistivity and mechanical properties of the 18Cr9Ni austenitic steel was examined. Swelling was measured both by immersion density and electron microscopy, reaching a maximum of ∼3 %. Swelling appears to be accelerated somewhat at these lower dpa rates as observed in other recent studies. Tensile properties were also measured. Radiation-induced changes of electrical resistivity, Young's and shear moduli were observed but did not agree fully with predictions based on voids alone. Strong contributions from second phase precipitates were found to be contributing to changes in both physical and mechanical properties. (authors)

Effects of irradiation on low-activation ferritic alloys to 45 dpa

International Nuclear Information System (INIS)

Gelles, D.S.; Hamilton, M.L.

1986-06-01

Nine low activation ferritic alloys covering the range 2 to 12Cr with alloying additions of tungsten and/or vanadium have been irradiated to intermediate fluences of 30 to 45 dpa and tensile tested or examined by transmission electron microscopy in order to determine the effect of increasing neutron dose on properties and microstructure. Changes in properties and microstructure are for the most part completed within 10 dpa but swelling and dislocation evolution continue with increasing dose at 420/degree/C and subgrain coarsening occurs at 600/degree/C. 9 refs., 7 figs., 2 tabs

The co-evolution of microstructure features in self-ion irradiated HT9 at very high damage levels

Energy Technology Data Exchange (ETDEWEB)

Getto, E., E-mail: getto@usna.edu [Department of Mechanical Engineering, United States Naval Academy, Annapolis, MD, 21402 (United States); Department of Nuclear Engineering and Radiological Sciences, University of Michigan, Ann Arbor, MI, 48109 (United States); Vancoevering, G.; Was, G.S. [Department of Nuclear Engineering and Radiological Sciences, University of Michigan, Ann Arbor, MI, 48109 (United States)

2017-02-15

Understanding the void swelling and phase evolution of reactor structural materials at very high damage levels is essential to maintaining safety and longevity of components in Gen IV fast reactors. A combination of ion irradiation and modeling was utilized to understand the microstructure evolution of ferritic-martensitic alloy HT9 at high dpa. Self-ion irradiation experiments were performed on alloy HT9 to determine the co-evolution of voids, dislocations and precipitates up to 650 dpa at 460 °C. Modeling of microstructure evolution was conducted using the modified Radiation Induced Microstructure Evolution (RIME) model, which utilizes a mean field rate theory approach with grouped cluster dynamics. Irradiations were performed with 5 MeV raster-scanned Fe{sup 2+} ions on samples pre-implanted with 10 atom parts per million He. The swelling, dislocation and precipitate evolution at very high dpa was determined using Analytical Electron Microscopy in Scanning Transmission Electron Microscopy (STEM) mode. Experimental results were then interpreted using the RIME model. A microstructure consisting only of dislocations and voids is insufficient to account for the swelling evolution observed experimentally at high damage levels in a complicated microstructure such as irradiated alloy HT9. G phase was found to have a minimal effect on either void or dislocation evolution. M{sub 2}X played two roles; a variable biased sink for defects, and as a vehicle for removal of carbon from solution, thus promoting void growth. When accounting for all microstructure interactions, swelling at high damage levels is a dynamic process that continues to respond to other changes in the microstructure as long as they occur.

Use of double and triple-ion irradiation to study the influence of high levels of helium and hydrogen on void swelling of 8-12% Cr ferritic-martensitic steels

Science.gov (United States)

Kupriiyanova, Y. E.; Bryk, V. V.; Borodin, O. V.; Kalchenko, A. S.; Voyevodin, V. N.; Tolstolutskaya, G. D.; Garner, F. A.

2016-01-01

In accelerator-driven spallation (ADS) devices, some of the structural materials will be exposed to intense fluxes of very high energy protons and neutrons, producing not only displacement damage, but very high levels of helium and hydrogen. Unlike fission flux-spectra where most helium and hydrogen are generated by transmutation in nickel and only secondarily in iron or chromium, gas production in ADS flux-spectra are rather insensitive to alloy composition, such that Fe-Cr base ferritic alloys also generate very large gas levels. While ferritic alloys are known to swell less than austenitic alloys in fission spectra, there is a concern that high gas levels in fusion and especially ADS facilities may strongly accelerate void swelling in ferritic alloys. In this study of void swelling in response to helium and hydrogen generation, irradiation was conducted on three ferritic-martensitic steels using the Electrostatic Accelerator with External Injector (ESUVI) facility that can easily produce any combination of helium to dpa and/or hydrogen to dpa ratios. Irradiation was conducted under single, dual and triple beam modes using 1.8 MeV Cr+3, 40 keV He+, and 20 keV H+. In the first part of this study we investigated the response of dual-phase EP-450 to variations in He/dpa and H/dpa ratio, focusing first on dual ion studies and then triple ion studies, showing that there is a diminishing influence on swelling with increasing total gas content. In the second part we investigated the relative response of three alloys spanning a range of starting microstructure and composition. In addition to observing various synergisms between He and H, the most important conclusion was that the tempered martensite phase, known to lag behind the ferrite phase in swelling in the absence of gases, loses much of its resistance to void nucleation when irradiated at large gas/dpa levels.

Preliminary Assessment of the Impact on Reactor Vessel dpa Rates Due to Installation of a Proposed Low Enriched Uranium (LEU) Core in the High Flux Isotope Reactor (HFIR)

Energy Technology Data Exchange (ETDEWEB)

Daily, Charles R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

2015-10-01

An assessment of the impact on the High Flux Isotope Reactor (HFIR) reactor vessel (RV) displacements-per-atom (dpa) rates due to operations with the proposed low enriched uranium (LEU) core described by Ilas and Primm has been performed and is presented herein. The analyses documented herein support the conclusion that conversion of HFIR to low-enriched uranium (LEU) core operations using the LEU core design of Ilas and Primm will have no negative impact on HFIR RV dpa rates. Since its inception, HFIR has been operated with highly enriched uranium (HEU) cores. As part of an effort sponsored by the National Nuclear Security Administration (NNSA), conversion to LEU cores is being considered for future HFIR operations. The HFIR LEU configurations analyzed are consistent with the LEU core models used by Ilas and Primm and the HEU balance-of-plant models used by Risner and Blakeman in the latest analyses performed to support the HFIR materials surveillance program. The Risner and Blakeman analyses, as well as the studies documented herein, are the first to apply the hybrid transport methods available in the Automated Variance reduction Generator (ADVANTG) code to HFIR RV dpa rate calculations. These calculations have been performed on the Oak Ridge National Laboratory (ORNL) Institutional Cluster (OIC) with version 1.60 of the Monte Carlo N-Particle 5 (MCNP5) computer code.

Further Charpy impact test results of low activation ferritic alloys, irradiated at 430 degrees C to 67 dpa

International Nuclear Information System (INIS)

Schubert, L.E.; Hamilton, M.L.; Gelles, D.S.

1997-01-01

Miniature CVN specimens of four ferritic alloys, GA3X, F82H, GA4X and HT9, have been impact tested following irradiation at 430 degrees C to 67 dpa. Comparison of the results with those of the previously tested lower dose irradiation condition indicates that the GA3X and F82H alloys, two primary candidate low activation alloys, exhibit virtually identical behavior following irradiation at 430 degrees C to ∼67 dpa and at 370 degrees C to ∼15 dpa. Very little shift is observed in either DBTT or USE relative to the unirradiated condition. The shifts in DBTT and USE observed in both GA4X and HT9 were smaller after irradiation at 430 degrees C to ∼67 dpa than after irradiation at 370 degrees C to ∼15 dpa

Further Charpy impact test results of low activation ferritic alloys, irradiated at 430{degrees}C to 67 dpa

Energy Technology Data Exchange (ETDEWEB)

Schubert, L.E.; Hamilton, M.L.; Gelles, D.S. [Pacific Northwest National Lab., Richland, WA (United States)

1997-04-01

Miniature CVN specimens of four ferritic alloys, GA3X, F82H, GA4X and HT9, have been impact tested following irradiation at 430{degrees}C to 67 dpa. Comparison of the results with those of the previously tested lower dose irradiation condition indicates that the GA3X and F82H alloys, two primary candidate low activation alloys, exhibit virtually identical behavior following irradiation at 430{degrees}C to {approximately}67 dpa and at 370{degrees}C to {approximately}15 dpa. Very little shift is observed in either DBTT or USE relative to the unirradiated condition. The shifts in DBTT and USE observed in both GA4X and HT9 were smaller after irradiation at 430{degrees}C to {approximately}67 dpa than after irradiation at 370{degrees}C to {approximately}15 dpa.

Irradiation creep and swelling of AISI 316 to exposures of 130 dpa at 385?400$deg;C

Science.gov (United States)

Garner, F. A.; Porter, D. L.

1988-07-01

The creep and swelling of AISI 316 stainless steel have been studied at 385 to 400°C in EBR-II to doses of 130 dpa. Most creep capsules were operated at constant stress and temperature but mid-life changes in these variables were also made. This paper concentrates on the behavior of the 20% cold-worked condition but five other conditions were also studied. Swelling at ⩽ 400° C was found to lose the sensitivity to stress exhibited at higher temperatures while the creep rate was found to retain linear dependencies on both stress and swelling rate. The creep coefficients extracted at 400°C agree with those found in other experiments conducted at higher temperatures. In the temperature range of ⩽ 400° C, swelling is in the recombinationdominated regime and the swelling rate falls strongly away from the ~1%/dpa rate observed at higher temperatures. These lower rates of creep and swelling, coupled with the attainment of high damage levels without failure, encourage the use of AISI 316 in the construction of water-cooled fusion first walls operating at temperatures below 400°C.

New remarks on KERMA factors and DPA cross section data in ACE files

International Nuclear Information System (INIS)

Konno, Chikara; Sato, Satoshi; Ohta, Masayuki; Kwon, Saerom; Ochiai, Kentaro

2016-01-01

KERMA factors and DPA cross section data are essential for nuclear heating and material damage estimation in fusion reactor designs. Recently we compared KERMA factors and DPA cross section data in the latest official ACE files of JENDL-4.0, ENDF/B-VII.1, JEFF-3.2 and FENDL-3.0 and it was found out that the KERMA factors and DPA cross section data of a lot of nuclei did not always agree among the nuclear data libraries. We investigated the nuclear data libraries and the nuclear data processing code NJOY and specified new reasons for the discrepancies; (1) incorrect nuclear data and NJOY bugs, (2) huge helium production cross section data, (3) gamma production data format in the nuclear data, (4) no detailed secondary particle data (energy–angular distribution data). These problems should be resolved based on this study.

New remarks on KERMA factors and DPA cross section data in ACE files

Energy Technology Data Exchange (ETDEWEB)

Konno, Chikara, E-mail: konno.chikara@jaea.go.jp; Sato, Satoshi; Ohta, Masayuki; Kwon, Saerom; Ochiai, Kentaro

2016-11-01

KERMA factors and DPA cross section data are essential for nuclear heating and material damage estimation in fusion reactor designs. Recently we compared KERMA factors and DPA cross section data in the latest official ACE files of JENDL-4.0, ENDF/B-VII.1, JEFF-3.2 and FENDL-3.0 and it was found out that the KERMA factors and DPA cross section data of a lot of nuclei did not always agree among the nuclear data libraries. We investigated the nuclear data libraries and the nuclear data processing code NJOY and specified new reasons for the discrepancies; (1) incorrect nuclear data and NJOY bugs, (2) huge helium production cross section data, (3) gamma production data format in the nuclear data, (4) no detailed secondary particle data (energy–angular distribution data). These problems should be resolved based on this study.

[{sup 18}F]DPA-714 PET imaging of translocator protein TSPO (18 kDa) in the normal and excitotoxically-lesioned nonhuman primate brain

Energy Technology Data Exchange (ETDEWEB)

Lavisse, S.; Inoue, K.; Jan, C.; Petit, F.; Dauguet, J.; Guillermier, M.; Rbah-Vidal, L.; Van Camp, N.; Aron-Badin, R.; Hantraye, P. [CEA, I2BM, MIRCen, Fontenay-aux-Roses (France); CEA, CNRS, URA2210, Fontenay-aux-Roses (France); Peyronneau, M.A.; Goutal, S.; Dolle, F. [CEA, I2BM, Service Hospitalier Frederic Joliot, Orsay (France); Remy, P. [CEA, I2BM, MIRCen, Fontenay-aux-Roses (France); CEA, CNRS, URA2210, Fontenay-aux-Roses (France); Service de Neurologie, CHU Henri Mondor, Creteil (France)

2014-12-09

We aimed to characterize pharmacologically the TSPO- radioligand [{sup 18}F]DPA-714 in the brain of healthy cynomolgus monkeys and evaluate the cellular origin of its binding in a model of neurodegeneration induced by intrastriatal injection of quinolinic acid (QA). [{sup 18}F]DPA-714 PET images were acquired before and at 2, 7, 14, 21, 49, 70, 91 days after putaminal lesioning. Blocking and displacement studies were carried out (PK11195). Different modelling approaches estimated rate constants and V{sub T} (total distribution volume) which was used to measure longitudinal changes in the lesioned putamen. Sections for immunohistochemical labelling were prepared at the same time-points to evaluate correlations between in vivo [{sup 18}F]DPA-714 binding and microglial/astrocytic activation. [{sup 18}F]DPA-714 showed a widespread distribution with a higher signal in the thalamus and occipital cortex and lower binding in the cerebellum. TSPO was expressed throughout the whole brain and about 73 % of [{sup 18}F]DPA-714 binding was specific for TSPO in vivo. The one-tissue compartment model (1-TCM) provided good and reproducible estimates of V{sub T} and rate constants, and V{sub T} values from the 1-TCM and the Logan approach were highly correlated (r {sup 2} = 0.85). QA lesioning induced an increase in V{sub T}, which was +17 %, +54 %, +157 % and +39 % higher than baseline on days 7, 14, 21 and 91 after QA injection, respectively. Immunohistochemistry revealed an early microglial and a delayed astrocytic activation after QA injection. [{sup 18}F]DPA-714 binding matched TSPO immunopositive areas and showed a stronger colocalization with CD68 microglia than with GFAP-activated astrocytes. [{sup 18}F]DPA-714 binds to TSPO with high specificity in the primate brain under normal conditions and in the QA model. This tracer provides a sensitive tool for assessing neuroinflammation in the human brain. (orig.)

Non-edible Oil Cakes as a Novel Substrate for DPA Production and Augmenting Biocontrol Activity of Paecilomyces variotii.

Science.gov (United States)

Arora, Kalpana; Sharma, Satyawati; Krishna, Suresh B N; Adam, Jamila K; Kumar, Ashwani

2017-01-01

The present study investigated the use of waste non-edible oil cakes (Jatropha, Karanja, Neem, and Mahua) as a substrate for the growth of Paecilomyces variotii and dipicolinic acid (DPA) production. Previous researches proved the efficacy of DPA in suppressing certain pathogens that are deleterious to the plants in the rhizosphere. DPA production was statistical optimized by amending non-edible oil cakes in growing media as nitrogen and sugars (Dextrose, Glucose, and Lactose) as carbon source. Plackett-Burman design (PBD), indicated that Jatropha cake, Karanja cake, and Dextrose were the most significant components ( p edible oil cakes as a substrate offer an efficient and viable approach for DPA production by P. variotii .

Design of power balance SRAM for DPA-resistance

Science.gov (United States)

Keji, Zhou; Pengjun, Wang; Liang, Wen

2016-04-01

A power balance static random-access memory (SRAM) for resistance to differential power analysis (DPA) is proposed. In the proposed design, the switch power consumption and short-circuit power consumption are balanced by discharging and pre-charging the key nodes of the output circuit and adding an additional short-circuit current path. Thus, the power consumption is constant in every read cycle. As a result, the DPA-resistant ability of the SRAM is improved. In 65 nm CMOS technology, the power balance SRAM is fully custom designed with a layout area of 5863.6 μm2. The post-simulation results show that the normalized energy deviation (NED) and normalized standard deviation (NSD) are 0.099% and 0.04%, respectively. Compared to existing power balance circuits, the power balance ability of the proposed SRAM has improved 53%. Project supported by the Zhejiang Provincial Natural Science Foundation of China (No. LQ14F040001), the National Natural Science Foundation of China (Nos. 61274132, 61234002), and the K. C. Wong Magna Fund in Ningbo University, China.

Microstructural examination of commercial ferritic alloys at 299 DPA

International Nuclear Information System (INIS)

Gelles, D.S.

1995-11-01

Microstructures and density change measurements are reported for Martensitic commercial steels HT-9 and Modified 9Cr-lMo (T9) and oxide dispersion strengthened ferritic alloys MA956 and NU957 following irradiation in the FFTF/MOTA at 420 degrees C to 200 DPA. Swelling as determined by density change remains below 2% for all conditions. Microstructures are found to be stable except in recrystallized grains of MA957, which are fabrication artifacts, with only minor swelling in the Martensitic steels and α' precipitation in alloys with 12% or more chromium. These results further demonstrate the high swelling resistance and microstructural stability of the ferritic alloy class

The translocator protein radioligand 18F-DPA-714 monitors antitumor effect of erufosine in a rat 9L intracranial glioma model

International Nuclear Information System (INIS)

Awde, Ali R.; Boisgard, Raphael; Theze, Benoit; Dubois, Albertine; Zheng, Jinzi; Winkeler, Alexandra; Dolle, Frederic; Jacobs, Andreas H.; Tavitian, Bertrand

2013-01-01

On the one hand, the translocator protein (TSPO) radioligand N,N-diethyl-2-(2-(4-(2- 18 F-fluoroethoxy)phenyl)-5,7-dimethylpyrazolo[1,5-a] pyrimidin-3-yl)acetamide ( 18 F-DPA-714) has been suggested to serve as an alternative radiotracer to image human glioma, and on the other hand the alkyl-phosphocholine erufosine (ErPC3) has been reported to induce apoptosis in otherwise highly apoptosis resistant glioma cell lines. The induction of apoptosis by ErPC3 requires TSPO, a mitochondrial membrane protein highly expressed in malignant gliomas. In this preclinical study, we monitored the effect of ErPC3 treatment in vivo using 18 F-DPA-714 PET. Methods: In vitro studies investigated the antitumor effect of ErPC3 in 9L rat gliosarcoma cells. In vivo, glioma-bearing rats were imaged with 18 F-DPA-714 for the time of treatment. Results: A significant decrease in 9L cell proliferation and viability and a significant increase in apoptosis and caspase-3 activation were demonstrated on ErPC3 treatment in cell culture. In the rat model, ErPC3 administration resulted in significant changes in 18 F-DPA-714 tumor uptake over the course of the treatment. Immunohistochemistry revealed reduced tumor volume and increased cell death in ErPC3-treated animals accompanied by infiltration of the tumor core by CD11b-positive micro-glia/macrophages and glial fibrillary acidic protein-positive astrocytes. Conclusion: Our findings demonstrate a potent antitumor effect of ErPC3 in vitro, in vivo, and ex vivo. PET imaging of TSPO expression using 18 F-DPA-714 allows effective monitoring and quantification of disease progression and response to ErPC3 therapy in intracranial 9L gliomas. (authors)

Neutron and Gamma Fluxes and dpa Rates for HFIR Vessel Beltline Region (Present and Upgrade Designs)

Energy Technology Data Exchange (ETDEWEB)

Blakeman, E.D.

2001-01-11

The Oak Ridge National Laboratory (ORNL) High Flux Isotope Reactor (HFIR) is currently undergoing an upgrading program, a part of which is to increase the diameters of two of the four radiation beam tubes (HB-2 and HB-4). This change will cause increased neutron and gamma radiation dose rates at and near locations where the tubes penetrate the vessel wall. Consequently, the rate of radiation damage to the reactor vessel wall at those locations will also increase. This report summarizes calculations of the neutron and gamma flux (particles/cm{sup 2}/s) and the dpa rate (displacements/atom/s) in iron at critical locations in the vessel wall. The calculated dpa rate values have been recently incorporated into statistical damage evaluation codes used in the assessment of radiation induced embrittlement. Calculations were performed using models based on the discrete ordinates methodology and utilizing ORNL two-dimensional and three-dimensional discrete ordinates codes. Models for present and proposed beam tube designs are shown and their results are compared. Results show that for HB-2, the dpa rate in the vessel wall where the tube penetrates the vessel will be increased by {approximately}10 by the proposed enlargement. For HB-4, a smaller increase of {approximately}2.6 is calculated.

Effect of DPA and 1-MCP on chemical compounds related to superficial scald of Granny Smith apples

Energy Technology Data Exchange (ETDEWEB)

Moggia, C.; Moya-Leon, M. A.; Pereira, M.; Yuri, J. A.; Lobos, G. A.

2010-07-01

Research was carried out to study the mode of action of diphenylamine (DPA) and 1-methylcyclopropene (1-MCP), on control of superficial scald of Granny Smith apples (Malus domestica Borkh.), and its relation with chemical compounds. Fruit was harvested from a commercial orchard in Chile, 182 and 189 days after full bloom and received the following treatments: DPA (2,000 ppm); 1-MCP (1.2 ppm) and control (no treatment). All fruit was stored for 4 or 6 months at 0 degree centigrade. A completely randomized factorial design was used (2 harvest dates by 3 post harvest treatments). Monthly measurements were made on maturity indices, ethylene production rate (EPR), scald related compounds [a-farnesene (AF), conjugated trienes (CT), total anti-oxidants (AO)], and cell membrane stability. Following 4 and 6 months of storage, plus 7 days at 20 degree centigrade, scald was evaluated. After 6 months, DPA-treated fruit, from both harvests, showed similar firmness, EPR and AO, compared to the control. However, AF and CT were lower, and cell membrane stability higher. Conversely, 1-MCP-treated fruit showed a noticeable EPR suppression and AF inhibition, along with higher firmness, lower CT and AO, compared to the control and DPA. Furthermore, cell membrane stability was superior to that of the control and similar to that of the DPA. Treated fruit (DPA and 1-MCP) showed an important reduction in scald compared to the control. The effect of 1-MCP on the investigated compounds and the reduction in scald, confirms that ethylene plays a major role on its development. (Author) 50 refs.

Use of double and triple-ion irradiation to study the influence of high levels of helium and hydrogen on void swelling of 8–12% Cr ferritic-martensitic steels

Energy Technology Data Exchange (ETDEWEB)

Kupriiyanova, Y.E., E-mail: fomenkoj@kipt.kharkov.ua [National Science Centre Kharkov Institute of Physics and Technology, 1, Akademicheskaya St., Kharkov, 61108 (Ukraine); Bryk, V.V.; Borodin, O.V.; Kalchenko, A.S.; Voyevodin, V.N.; Tolstolutskaya, G.D. [National Science Centre Kharkov Institute of Physics and Technology, 1, Akademicheskaya St., Kharkov, 61108 (Ukraine); Garner, F.A. [Radiation Effects Consulting, Richland, WA 99354 (United States)

2016-01-15

In accelerator-driven spallation (ADS) devices, some of the structural materials will be exposed to intense fluxes of very high energy protons and neutrons, producing not only displacement damage, but very high levels of helium and hydrogen. Unlike fission flux-spectra where most helium and hydrogen are generated by transmutation in nickel and only secondarily in iron or chromium, gas production in ADS flux-spectra are rather insensitive to alloy composition, such that Fe–Cr base ferritic alloys also generate very large gas levels. While ferritic alloys are known to swell less than austenitic alloys in fission spectra, there is a concern that high gas levels in fusion and especially ADS facilities may strongly accelerate void swelling in ferritic alloys. In this study of void swelling in response to helium and hydrogen generation, irradiation was conducted on three ferritic-martensitic steels using the Electrostatic Accelerator with External Injector (ESUVI) facility that can easily produce any combination of helium to dpa and/or hydrogen to dpa ratios. Irradiation was conducted under single, dual and triple beam modes using 1.8 MeV Cr{sup +3}, 40 keV He{sup +}, and 20 keV H{sup +}. In the first part of this study we investigated the response of dual-phase EP-450 to variations in He/dpa and H/dpa ratio, focusing first on dual ion studies and then triple ion studies, showing that there is a diminishing influence on swelling with increasing total gas content. In the second part we investigated the relative response of three alloys spanning a range of starting microstructure and composition. In addition to observing various synergisms between He and H, the most important conclusion was that the tempered martensite phase, known to lag behind the ferrite phase in swelling in the absence of gases, loses much of its resistance to void nucleation when irradiated at large gas/dpa levels.

Comparison of fracture behavior for low-swelling ferritic and austenitic alloys irradiated in the Fast Flux Test Facility (FFTF) to 180 DPA

International Nuclear Information System (INIS)

Huang, F.H.

1992-02-01

Fracture toughness testing was conducted to investigate the radiation embrittlement of high-nickel superalloys, modified austenitic steels and ferritic steels. These materials have been experimentally proven to possess excellent resistance to void swelling after high neutron exposures. In addition to swelling resistance, post-irradiation fracture resistance is another important criterion for reactor material selection. By means of fracture mechanics techniques the fracture behavior of those highly irradiated alloys was characterized in terms of irradiation and test conditions. Precipitation-strengthened alloys failed by channel fracture with very low postirradiation ductility. The fracture toughness of titanium-modified austenitic stainless steel D9 deteriorates with increasing fluence to about 100 displacement per atom (dpa), the fluence level at which brittle fracture appears to occur. Ferritic steels such as HT9 are the most promising candidate materials for fast and fusion reactor applications. The upper-shelf fracture toughness of alloy HT9 remained adequate after irradiation to 180 dpa although its ductile- brittle transition temperature (DBTT) shift by low temperature irradiation rendered the material susceptible to brittle fracture at room temperature. Understanding the fracture characteristics under various irradiation and test conditions helps reduce the potential for brittle fracture by permitting appropriate measure to be taken

Damage structure in Nimonic PE16 alloy ion bombarded to high doses and gas levels

International Nuclear Information System (INIS)

Farrell, K.; Packan, N.H.

1981-01-01

The Nimonic PE16 alloy in solution-treated-and-aged condition was bombarded simultaneously with nickel ions and α and deuteron beams at 625 0 C to doses of 80 to 313 dpa at He/dpa = 10 and D/dpa = 25. Microstructural changes consisted of the introduction of dislocations and of cavities, and the redistribuion of γ' precipitates to these defects. Cavitational swelling remained below 1%. Cavities were represented by several distinct size classes, the smaller ones believed to be gas bubbles, and some larger ones associated with preferred growth of precipitate. Formation of bubbles at grain boundaries, and large cavities at incoherent twins intensified the possibility of mechanical separation of interfaces under high-gas irradiation conditions

The influence of He/dpa ratio and displacement rate on microstructural evolution: a comparison of theory and experiment

International Nuclear Information System (INIS)

Katoh, Yutai; Stoller, Roger E.; Kohno, Yutaka; Kohyama, Akira

1994-01-01

A kinetic model was developed to investigate the influence of the displacement rate and helium generation rate on microstructural evolution in austenitic stainless steels. The model integrates the rate equations describing the evolution of point defects, small point defect clusters, helium-vacancy clusters, and the larger cavity size distribution that is responsible for observable swelling. Cavity (bubble) nucleation is accounted for by the helium-vacancy cluster evolution, while void formation occurs when bubbles grow beyond a critical size in the larger cavity distribution. A series of ion irradiation experiments were used to both calibrate the model and to provide a comparison between model predictions and experimental observations. The experiments involved single and dual-beam irradiations of solution annealed AISI-316 stainless steel at 873 K. The displacement rates were in the range of 2x10 -3 to 1x10 -2 dpa/s and the helium-to-dpa ratios were in the range of 0 to 50 appm He/dpa. The maximum displacement dose was 25 dpa. The experiments revealed a significant effect of helium on both the dislocation structure and the cavity distribution. The model predictions of helium effects over a broad range of He/dpa ratios and displacement rates were consistent with experimental observations. ((orig.))

Relationship between swelling and irradiation creep in cold-worked PCA stainless steel irradiated to similar 178 dpa at similar 400 C

International Nuclear Information System (INIS)

Toloczko, M.B.; Garner, F.A.

1994-01-01

The eighth and final irradiation segment for pressurized tubes constructed from the fusion Prime Candidate Alloy (PCA) has been completed in FFTF. At 178 dpa and similar 400 C, the irradiation creep of 20% cold-worked PCA has become dominated by the ''creep disappearance'' phenomenon. The total diametral deformation rate has reached the limiting value of 0.33%/dpa at the three highest stress levels employed in this test. The stress-enhancement of swelling tends to camouflage the onset of creep disappearance, however, requiring the use of several non-traditional techniques to extract the creep coefficients. No failures occurred in these tubes, even though the swelling ranged from similar 20 to 40%. ((orig.))

Relationship between swelling and irradiation creep in cold-worked PCA stainless steel irradiated to similar 178 dpa at similar 400 C

Energy Technology Data Exchange (ETDEWEB)

Toloczko, M.B. (Department of Chemical and Nuclear Engineering, University of California, Santa Barbara, CA 93106 (United States)); Garner, F.A. (Pacific Northwest Laboratory, Richland, WA 99352 (United States))

1994-09-01

The eighth and final irradiation segment for pressurized tubes constructed from the fusion Prime Candidate Alloy (PCA) has been completed in FFTF. At 178 dpa and similar 400 C, the irradiation creep of 20% cold-worked PCA has become dominated by the creep disappearance'' phenomenon. The total diametral deformation rate has reached the limiting value of 0.33%/dpa at the three highest stress levels employed in this test. The stress-enhancement of swelling tends to camouflage the onset of creep disappearance, however, requiring the use of several non-traditional techniques to extract the creep coefficients. No failures occurred in these tubes, even though the swelling ranged from similar 20 to 40%. ((orig.))

Non-edible Oil Cakes as a Novel Substrate for DPA Production and Augmenting Biocontrol Activity of Paecilomyces variotii

Directory of Open Access Journals (Sweden)

Ashwani Kumar

2017-05-01

Full Text Available The present study investigated the use of waste non-edible oil cakes (Jatropha, Karanja, Neem, and Mahua as a substrate for the growth of Paecilomyces variotii and dipicolinic acid (DPA production. Previous researches proved the efficacy of DPA in suppressing certain pathogens that are deleterious to the plants in the rhizosphere. DPA production was statistical optimized by amending non-edible oil cakes in growing media as nitrogen and sugars (Dextrose, Glucose, and Lactose as carbon source. Plackett-Burman design (PBD, indicated that Jatropha cake, Karanja cake, and Dextrose were the most significant components (p < 0.05 of the media and were further optimized using response surface methodology (RSM. Jatropha cake, Karanja cake, and Dextrose at the concentration of 12.5, 4.5, and 10 g/l, respectively, yielded 250 mg/l of DPA, which was 2.5 fold more than that obtained from basal medium. HPLC analysis of the optimized medium (peak at retention time of 30 min confirmed the enhanced DPA production by P. variotii. The scanning electron microscopy (SEM images showed that optimized medium impose a stress like condition (due to less C:N ratio for the fungus and generated more spores as compared to the basal medium in which carbon source is easily available for the mycelial growth. The antimicrobial activity of the fungal extract was tested and found to be effective even at 10−2 dilution after 72 h against two plant pathogens, Fusarium oxysporum and Verticillium dahlia. Statistical experimental design of this study and the use of non-edible oil cakes as a substrate offer an efficient and viable approach for DPA production by P. variotii.

Relationship between swelling and irradiation creep in cold-worked PCA stainless steel irradiated to ∼178 dpa at ∼400 degrees C

International Nuclear Information System (INIS)

Toloczko, M.B.

1993-09-01

The eighth and final irradiation segment for pressurized tubes constructed from the fusion Prime Candidate Alloy (PCA) has been completed in FFTF. At 178 dpa and ∼400 degrees C, the irradiation creep of 20% cold-worked PCA has become dominated by the open-quotes creep disappearanceclose quotes phenomenon. The total diametral deformation rate has reached the limiting value of 0.33%/dpa at the three highest stress levels employed in this test. The stress-enhancement of swelling tends to camouflage the onset of creep disappearance, however, requiring the use of several non-traditional techniques to extract the creep coefficients. No failures occurred in these tubes, even though the swelling ranged from ∼20 to ∼40%

Experimental Charge Density Study of Trichromium Linear Metal String Complex – Cr3(dpa)4Cl2

DEFF Research Database (Denmark)

Wu, Lai-Chin; Cheng, Ming-Chuan; Thomsen, Maja Krüger

An experimental and theoretical charge density study, based on Bader’s Quantum Theory: Atoms in Molecule (QTAIM), on a trichromium metal string complex, Cr3(dpa)4Cl2(C2H5OC2H5)x(CH2Cl2)1-x (1, dpa- = bis(2-pyridyl)amido)) is performed. The structure and multipole model of 1 are performed by using...... experimental X-ray diffraction data which are collected at both 100 K using conventional X-ray source (DS1) and 15 K using synchrotron source (DS2). The three chromium metal string is bridged by four dpa- ligands. These tri-chromium metal ions are bonded to each other and terminated by two Cl- ions on the both...... ends, forming a [Cl(1)Cr(1)Cr(2)Cr(3)Cl(2)] linear string. Each Cr atoms are coordinated by four N atoms of each dpa- ligand. This metal string is slightly unsymmetrical at both data sets. The bond distance, from DS1 (DS2), of Cr(1)Cr(2), 2.3480(2) (2.3669(1)) Å, is 0.03 (0.003) Å shorter than Cr...

Primary Damage in Ceramics: Complexity and Inapplicability of the NRT Dpa

International Nuclear Information System (INIS)

Crocombette, Jean-Paul

2012-01-01

It is shown that the studies on ceramics bring even more complexity is an already difficult situation about the NRT dpa. First in ceramics amorphized by direct impact, the very concept of surviving FPs which is what the NRT dpa is supposed to measure is meaningless. One then has to return to the bare number of displaced atoms to quantify the damage. Second in more complex situations where the damage is mixed between amorphization and creation of point defects, it is almost impossible to define a quantity to measure atomic disorder induced by cascades. Finally it was shown that the amount and nature of damage depends not only on the energy of the PKA but also on its nature. Finally one should keep in mind that even in the regular cases, the number of surviving Frenkel pairs may vary with temperature as their recombinations can be thermally activated

Analysis and recommendations for DPA calculations in SiC

International Nuclear Information System (INIS)

Heinisch, H.L.

1998-01-01

Recent modeling results, coupled with the implications of available experimental results, provide sufficient information to achieve consensus on the values of threshold displacement energies to use in displacements per atom (DPA) calculations. The values recommended here, 20 eV for C and 35 eV for Si, will be presented for adoption by the international fusion materials community at the next IEA SiC/SiC workshop

Analysis of Proton Induced Material Damage Using the DPA Cross-sections Based on NRT and BCA-MD Models

Energy Technology Data Exchange (ETDEWEB)

Kim, Kyung-O; Roh, Gyuhong; Lee, Byungchul [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2016-10-15

The level of radiation induced material damage is mainly quantified by using the unit of Displacements Per Atom (DPA), and particularly, the displacement cross-section is used for characterizing/analyzing the radiation damage from incident neutrons and charged particles. Not long ago, the standard Norgett-Robinson-Torrens (NRT) model had been applied to produce the nuclear data due to its simplicity and implementation in commonly used codes, such as NJOY and MCNP codes. However, the evaluations based on NRT model represent the severe disagreement with experimental data and more accurate calculations. Hence, the evaluations with existing and new nuclear data are performed/compared in this study. It is assumed that a high energy proton beam is directly moved to the target, and a series of calculations are performed by using MCNPX code. The proton induced material damage is evaluated by using the displacement cross-sections, and the effect of nuclear data on the evaluation is specifically analyzed with MCNPX code. First, there is significant difference between the nuclear data from existing and new models, and the new evaluated data is generally lower than the existing one. Second, the position of maximum DPA is slightly differed with the position of maximum energy deposition, and the evaluation using new evaluated data is lower about 2 times than the other.

Synthesis of [Dy(DPA)(HDPA)] and its potential as gunshot residue marker

Energy Technology Data Exchange (ETDEWEB)

Melo Lucena, Marcella A. [PGMTR - CCEN, Federal University of Pernambuco - UFPE, Avenida Professor Luiz Freire, S/N, Cidade Universitária, 50740-540 Recife (Brazil); Rodrigues, Marcelo Oliveira; Gatto, Claudia C. [LIMA, Chemistry Institute, University of Brasília-UNB, P.O. Box 04478, 70904-970 Brasília (Brazil); Talhavini, Marcio; Maldaner, Adriano O. [National Institute of Criminalistics, Brazilian Federal Police, SAIS Quadra 07, Lote 23, 70610-200 Brasília, DF (Brazil); Alves, Severino [Fundamental Chemistry Department-DQF, Federal University of Pernambuco - UFPE, Avenida Professor Luiz Freire, S/N, Cidade Universitária, 50740-540 Recife (Brazil); Weber, Ingrid T., E-mail: ingrid@ufpe.br [PGMTR - CCEN, Federal University of Pernambuco - UFPE, Avenida Professor Luiz Freire, S/N, Cidade Universitária, 50740-540 Recife (Brazil); LIMA, Chemistry Institute, University of Brasília-UNB, P.O. Box 04478, 70904-970 Brasília (Brazil)

2016-02-15

The 2D metal-organic framework (MOF) [Dy(DPA)(HDPA)] (where H{sub 2}DPA=dipicolinic acid) was synthesized under hydrothermal conditions and exhibited a whitish yellow color (CIE coordinates: 0.362, 0.416) when excited at 365 nm. This color arises from the simultaneous blue ({sup 4}F{sub 9/2}–{sup 6}H{sub 15/2}), yellow ({sup 4}F{sub 9/2}–{sup 6}H{sub 13/2}) and red ({sup 4}F{sub 9/2}–{sup 6}H{sub 11/2}) transitions of Dy{sup 3+}. This MOF exhibited a high potential for use as a luminescent marker for gunshot residue (GSR) and in the ammunition encoding process because it was possible to observe visually the luminescent gunshot residue (LGSR) on the shooter’s hands, both on the firearm and at the firing range, using an UV lamp. These particles were easily collected and characterized by photoluminescence spectroscopy and SEM–EDS. The particles exhibited a typical morphology and a composition, making them easy to differentiate from particles of occupational or environmental origin. - Highlights: • First example of a luminescent GSR marker based on Dy{sup 3+} luminescence. • New luminescent marker which can be used for ammunition encoding process. • Thermal and chemically stable MOF which can be used to visually identify GSR.

Continuous gradient temperature Raman spectroscopy and differential scanning calorimetry of N-3DPA and DHA from -100 to 10°C.

Science.gov (United States)

Broadhurst, C Leigh; Schmidt, Walter F; Nguyen, Julie K; Qin, Jianwei; Chao, Kuanglin; Aubuchon, Steven R; Kim, Moon S

2017-04-01

Docosahexaenoic acid (DHA, 22:6n-3) is exclusively utilized in fast signal processing tissues such as retinal, neural and cardiac. N-3 docosapentaenoic acid (n-3DPA, 22:5n-3), with just one less double bond, is also found in the marine food chain yet cannot substitute for DHA. Gradient temperature Raman spectroscopy (GTRS) applies the temperature gradients utilized in differential scanning calorimetry (DSC) to Raman spectroscopy, providing a straightforward technique to identify molecular rearrangements that occur near and at phase transitions. Herein we apply GTRS and both conventional and modulated DSC to n-3DPA and DHA from -100 to 20°C. Three-dimensional data arrays with 0.2°C increments and first derivatives allowed complete assignment of solid, liquid and transition state vibrational modes. Melting temperatures n-3DPA (-45°C) and DHA (-46°C) are similar and show evidence for solid-state phase transitions not seen in n-6DPA (-27°C melt). The C6H2 site is an elastic marker for temperature perturbation of all three lipids, each of which has a distinct three dimensional structure. N-3 DPA shows the spectroscopic signature of saturated fatty acids from C1 to C6. DHA does not have three aliphatic carbons in sequence; n-6DPA does but they occur at the methyl end, and do not yield the characteristic signal. DHA appears to have uniform twisting from C6H2 to C12H2 to C18H2 whereas n-6DPA bends from C12 to C18, centered at C15H2. For n-3DPA, twisting is centered at C6H2 adjacent to the C2-C3-C4-C5 aliphatic moiety. These molecular sites are the most elastic in the solid phase and during premelting. Copyright © 2017 Elsevier B.V. All rights reserved.

Effects of neutron irradiation at 4500C and 16 dpa on the properties of various commercial copper alloys

International Nuclear Information System (INIS)

Brager, H.R.; Heinisch, H.L.; Garner, F.A.

1985-01-01

High-purity copper and eight copper alloys were irradiated to approx.16 dpa at approx.450 0 C in the MOTA experiment in FFTF. These alloys were also examined after aging at 400 0 C for 1000 hours. The radiation-induced changes in the electrical conductivity, tensile properties, and density were measured and compared to those of the aged materials. The changes in conductivity can be either positive or negative depending on the alloy. Changes in tensile properties of most, but not all, of the alloys seem to be primarily dependent on thermal effects rather than the effect of atomic displacements. Radiation at 450 0 C induced changes in density varying from 0.66% densification to 16.6% swelling. The latter occurred in Cu-O.1% Ag and implies a swelling rate of at least 1%/dpa. 6 references, 3 figures, 2 tables

A Calculation Method of PKA, KERMA and DPA from Evaluated Nuclear Data with an Effective Single-particle Emission Approximation (ESPEA) and Introduction of Event Generator Mode in PHITS Code

International Nuclear Information System (INIS)

Fukahori, Tokio; Iwamoto, Yosuke

2012-01-01

The displacement calculation method from evaluated nuclear data file has been developed by using effective single-particle emission approximation (ESPEA). The ESPEA can be used effectively below about 50 MeV, because of since multiplicity of emitted particles. These are also reported in the Ref. 24. The displacement calculation method in PHITS has been developed. In the high energy region (≥ 20 MeV) for proton and neutron beams, DPA created by secondary particles increase due to nuclear reactions. For heavy-ion beams, DPA created by the primaries are dominant to total DPA due to the large Coulomb scattering cross sections. PHITS results agree with FLUKA ones within a factor of 1.7. In the high-energy region above 10 MeV/nucleon, comparisons among codes and measurements of displacement damage cross section are necessary. (author)

Quantification of TSPO overexpression in a rat model of local neuroinflammation induced by intracerebral injection of LPS by the use of [18F]DPA-714 PET

International Nuclear Information System (INIS)

Ory, Dieter; Celen, Sofie; Verbruggen, Alfons; Bormans, Guy; Postnov, Andrey; Koole, Michel; Laat, Bart de; Laere, Koen van; Casteels, Cindy

2016-01-01

[ 18 F]DPA-714 is a radiotracer with high affinity for TSPO. We have characterized the kinetics of [ 18 F]DPA-714 in rat brain and evaluated its ability to quantify TSPO expression with PET using a neuroinflammation model induced by unilateral intracerebral injection of lipopolysaccharide (LPS). Dynamic small-animal PET scans with [ 18 F]DPA-714 were performed in Wistar rats on a FOCUS-220 system for up to 3 h. Both plasma and perfused brain homogenates were analysed using HPLC to quantify radiometabolites. Full kinetic modelling of [ 18 F]DPA-714 brain uptake was performed using a metabolite-corrected arterial plasma input function. Binding potential (BP ND ) calculated as the distribution volume ratio minus one (DVR-1) between affected and healthy brain tissue was used as the outcome measure and evaluated against reference tissue models. The percentage of intact [ 18 F]DPA-714 in arterial plasma samples was 92 ± 4 % at 10 min, 75 ± 8 % at 40 min and 52 ± 6 % at 180 min. The radiometabolite fraction in brain was negligible (<3 % at 30 min). Among the models investigated, the reversible two-tissue (2T) compartment model best described [ 18 F]DPA-714 brain kinetics. BP ND values obtained with a simplified and a multilinear reference tissue model (SRTM, MRTM) using the contralateral striatum as the reference region correlated well (Spearman's r = 0.96, p ≤ 0.003) with 2T BP ND values calculated as DVR-1, and showed comparable bias (bias range 17.94 %, 20.32 %). Analysis of stability over time suggested that the acquisition time should be at least 90 min for SRTM and MRTM. Quantification of [ 18 F]DPA-714 binding to TSPO with full kinetic modelling is feasible using a 2T model. SRTM and MRTM can be suggested as reasonable substitutes with the contralateral striatum as the reference region and a scan duration of at least 90 min. However, selection of the reference region depends on the disease model used. (orig.)

A functional method for estimating DPA tallies in Monte Carlo calculations of Light Water Reactors

International Nuclear Information System (INIS)

Read, Edward A.; Oliveira, Cassiano R.E. de

2011-01-01

There has been a growing need in recent years for the development of methodology to calculate radiation damage factors, namely displacements per atom (dpa), of structural components for Light Water Reactors (LWRs). The aim of this paper is to discuss the development and implementation of a dpa method using Monte Carlo method for transport calculations. The capabilities of the Monte Carlo code Serpent such as Woodcock tracking and fuel depletion are assessed for radiation damage calculations and its capability demonstrated and compared to those of the Monte Carlo code MCNP for radiation damage calculations of a typical LWR configuration. (author)

Imaging of brain TSPO expression in a mouse model of amyotrophic lateral sclerosis with 18F-DPA-714 and micro-PET/CT

International Nuclear Information System (INIS)

Gargiulo, S.; Gramanzini, M.; Anzilotti, S.; Salvatore, M.; Coda, A.R.D.; Panico, M.; Zannetti, A.; Vicidomini, C.; Quarantelli, M.; Pappata, S.; Greco, A.; Brunetti, A.; Vinciguerra, A.; Pignataro, G.; Dolle, F.; Annunziato, L.

2016-01-01

To evaluate the feasibility and sensitivity of 18 F-DPA-714 for the study of microglial activation in the brain and spinal cord of transgenic SOD1 G93A mice using high-resolution PET/CT and to evaluate the Iba1 and TSPO expression with immunohistochemistry. Nine symptomatic SOD1 G93A mice (aged 117 ± 12.7 days, clinical score range 1 - 4) and five WT SOD1 control mice (aged 108 ± 28.5 days) underwent 18 F-DPA-714 PET/CT. SUV ratios were calculated by normalizing the cerebellar (rCRB), brainstem (rBS), motor cortex (rMCX) and cervical spinal cord (rCSC) activities to that of the frontal association cortex. Two WT SOD1 and six symptomatic SOD1 G93A mice were studied by immunohistochemistry. In the symptomatic SOD1 G93A mice, rCRB, rBS and rCSC were increased as compared to the values in WT SOD1 mice, with a statistically significantly difference in rBS (2.340 ± 0.784 vs 1.576 ± 0.287, p = 0.014). Immunofluorescence studies showed that TSPO expression was increased in the trigeminal, facial, ambiguus and hypoglossal nuclei, as well as in the spinal cord, of symptomatic SOD1 G93A mice and was colocalized with increased Iba1 staining. Increased 18 F-DPA-714 uptake can be detected with high-resolution PET/CT in the brainstem of transgenic SOD1 G93A mice, a region known to be a site of degeneration and increased microglial activation in amyotrophic lateral sclerosis, in agreement with increased TSPO expression in the brainstem nuclei shown by immunostaining. Therefore, 18 F-DPA-714 PET/CT might be a suitable tool to evaluate microglial activation in the SOD1 G93A mouse model. (orig.)

Tensile behavior of RAFM alloys after neutron irradiation of up to 16.3 dpa between 250 and 450 °C

International Nuclear Information System (INIS)

Materna-Morris, E.; Schneider, H.-C.; Möslang, A.

2014-01-01

Tensile specimen of steel EUROFER97 and other alloys on the basis of RAFM steels such, as OPTIFER and F82H alloys, and Ga3X were irradiated and post-examined during a neutron irradiation program of up to 16.3 dpa between 250 and 450 °C in the HFR (High Flux Reactor) in the Netherlands. These tensile results were compared with former irradiation programs, with lower neutron doses of up to 0.8 and 2.4 dpa to quantify the difference in tensile strengthening. The average increase of tensile strength was in a range of 300 MPa between 0.8 and 16.3 dpa at temperatures of 250–300 °C. This behavior can be correlated with irradiation-induced changes in the microstructure. Most of the hardening can be attributed to dislocation loops, point defects or small precipitates as observed in boron-free alloys as F82H mod. and EUROFER97. Whereas the hardening in boron-containing alloys OPTIFER alloys and Ga3X can be correlated in addition with the combination of helium bubbles. At the highest irradiation and test temperature at 450 °C, all tensile data of all investigated materials were in the range of those of non-irradiated and irradiated material due to thermal aging effects

Tensile behavior of RAFM alloys after neutron irradiation of up to 16.3 dpa between 250 and 450 °C

Energy Technology Data Exchange (ETDEWEB)

Materna-Morris, E., E-mail: edeltraud.materna-morris@kit.edu; Schneider, H.-C., E-mail: hans-christian.schneider@kit.edu; Möslang, A., E-mail: anton.moeslang@kit.edu

2014-12-15

Tensile specimen of steel EUROFER97 and other alloys on the basis of RAFM steels such, as OPTIFER and F82H alloys, and Ga3X were irradiated and post-examined during a neutron irradiation program of up to 16.3 dpa between 250 and 450 °C in the HFR (High Flux Reactor) in the Netherlands. These tensile results were compared with former irradiation programs, with lower neutron doses of up to 0.8 and 2.4 dpa to quantify the difference in tensile strengthening. The average increase of tensile strength was in a range of 300 MPa between 0.8 and 16.3 dpa at temperatures of 250–300 °C. This behavior can be correlated with irradiation-induced changes in the microstructure. Most of the hardening can be attributed to dislocation loops, point defects or small precipitates as observed in boron-free alloys as F82H mod. and EUROFER97. Whereas the hardening in boron-containing alloys OPTIFER alloys and Ga3X can be correlated in addition with the combination of helium bubbles. At the highest irradiation and test temperature at 450 °C, all tensile data of all investigated materials were in the range of those of non-irradiated and irradiated material due to thermal aging effects.

On the ductile-to-brittle transition behavior of martensitic alloys neutron irradiated to 26 dpa

International Nuclear Information System (INIS)

Hu, W.L.; Gelles, D.S.

1987-01-01

Charpy impact tests were conducted on specimens made of HT-9 and 9Cr-1Mo in various heat treatment conditions which were irradiated in EBR-II to 26 dpa at 390 to 500 0 C. The results are compared with previous results on specimens irradiated to 13 dpa. HT-9 base metal irradiated at low temperatures showed a small additional increase in ductile brittle transition temperature and a decrease in upper shelf energy from 13 to 26 dpa. No fluence effect was observed in 9Cr-1Mo base metal. The 9Cr-1Mo weldment showed degraded DBTT but improved USE response compared to base metal, contrary to previous findings on HT-9. Significant differences were observed in HT-9 base metal between mill annealed material and normalized and tempered material. The highest DBTT for HT-9 alloys was 50 0 C higher than for the worst case in 9Cr-1Mo alloys. Fractography and hardness measurements were also obtained. Significant differences in fracture appearance were observed in different product forms, although no dependence on fluence was observed. Failure was controlled by the preirradiation microstructure

TENDL-TMC for Δdpa and Δpka

International Nuclear Information System (INIS)

Rochman, D.; Ferroukhi, H.; Koning, A.J.; Sjostrand, H.; Helgesson, P.; Gilbert, M.; Sublet, J.C.

2016-01-01

Full text: The TENDL library (Talys Evaluated Nuclear Data Library) contains the necessary information (e.g. recoil spectra, double differential data) to calculate quantities of interest for the material damage. Additionally, it is one of the most complete libraries in terms of number of isotopes and format-wise: 2800 isotopes (ground states and isomers) and all ENDF-6 sections from MF1 to MF40. It can then be naturally used for the estimation of “DPA” and “PKA”, given the correct NJOY processing. Details of the library, its production, formatting and processing are given during the technical meeting. Comparison with other libraries indicated the importance of including all the “MT” sections for the correct processing with NJOY, but also it showed the difference obtained depending of the format chosen to store the decay data. Regarding the uncertainties on DPA and PKA, the TMC method seems to be one of the most convenient methods. As presented during the meeting, the uncertainty propagation using random ENDF-6 files produced from variations of model parameters leads to non-Gaussian distributions for the damage quantities. As a function of the incident neutron energy, the skewness of such distributions can strongly vary and be far from 0. This indicates that the standard deviation alone cannot represent, well enough, the dispersion of the calculated data. A viable alternative is the production of so-called random ENDF-6 files based on given covariance information. This method is limited by the available information given in the covariance files, but can help to capture part of the uncertainties for the DPA and PKA quantities. For TENDL-2016, the covariance format MF32 will be less used and efforts will be devoted to produce MF33, which will facilitate the production of random ENDF-6 files with SCK codes such as SANDY. A PSI internal project to link the nuclear data with the atomistic simulation of damage formation and microstructure evolution was also

Swelling and microstructural development in path A PCA and type 316 stainless steel irradiated in HFIR to about 22 dpa

International Nuclear Information System (INIS)

Maziasz, P.J.; Braski, D.N.

1983-01-01

Irradiation of several microstructural variants of PCA and 20%-cold-worked N-lot type 316 stainess steel (CW 316) in HFIR to about 10 dpa produced no visible cavities at 300 0 C, bubbles at 400 0 C, and varying distributions of bubbles and voids at 500 and 600 0 C. The PCA-B1 swells the most and CW 316 (N-lot) the least at 600 0 C. Irradiations have been extended to about 22 dpa. The PCA-Al swells 0.06%/dpa at 600 0 C but at a much lower rate at 500 0 C. The PCA-A3 shows the lowest swelling at 600 0 C, about the half the swelling rate of type 316 stainless steel

Quantification of TSPO overexpression in a rat model of local neuroinflammation induced by intracerebral injection of LPS by the use of [{sup 18}F]DPA-714 PET

Energy Technology Data Exchange (ETDEWEB)

Ory, Dieter; Celen, Sofie; Verbruggen, Alfons; Bormans, Guy [KU Leuven, Laboratory for Radiopharmacy, Department of Pharmaceutical and Pharmacological Sciences, Leuven (Belgium); Postnov, Andrey; Koole, Michel; Laat, Bart de; Laere, Koen van; Casteels, Cindy [University Hospital and KU Leuven, Nuclear Medicine and Molecular Imaging, Department of Imaging and Pathology, Leuven (Belgium)

2016-01-15

[{sup 18}F]DPA-714 is a radiotracer with high affinity for TSPO. We have characterized the kinetics of [{sup 18}F]DPA-714 in rat brain and evaluated its ability to quantify TSPO expression with PET using a neuroinflammation model induced by unilateral intracerebral injection of lipopolysaccharide (LPS). Dynamic small-animal PET scans with [{sup 18}F]DPA-714 were performed in Wistar rats on a FOCUS-220 system for up to 3 h. Both plasma and perfused brain homogenates were analysed using HPLC to quantify radiometabolites. Full kinetic modelling of [{sup 18}F]DPA-714 brain uptake was performed using a metabolite-corrected arterial plasma input function. Binding potential (BP{sub ND}) calculated as the distribution volume ratio minus one (DVR-1) between affected and healthy brain tissue was used as the outcome measure and evaluated against reference tissue models. The percentage of intact [{sup 18}F]DPA-714 in arterial plasma samples was 92 ± 4 % at 10 min, 75 ± 8 % at 40 min and 52 ± 6 % at 180 min. The radiometabolite fraction in brain was negligible (<3 % at 30 min). Among the models investigated, the reversible two-tissue (2T) compartment model best described [{sup 18}F]DPA-714 brain kinetics. BP{sub ND} values obtained with a simplified and a multilinear reference tissue model (SRTM, MRTM) using the contralateral striatum as the reference region correlated well (Spearman's r = 0.96, p ≤ 0.003) with 2T BP{sub ND} values calculated as DVR-1, and showed comparable bias (bias range 17.94 %, 20.32 %). Analysis of stability over time suggested that the acquisition time should be at least 90 min for SRTM and MRTM. Quantification of [{sup 18}F]DPA-714 binding to TSPO with full kinetic modelling is feasible using a 2T model. SRTM and MRTM can be suggested as reasonable substitutes with the contralateral striatum as the reference region and a scan duration of at least 90 min. However, selection of the reference region depends on the disease model used. (orig.)

Reduced PBR/TSPO Expression After Minocycline Treatment in a Rat Model of Focal Cerebral Ischemia: A PET Study Using [18F]DPA-714

International Nuclear Information System (INIS)

Martin, A.; Boisgard, R.; Tavitian, B.; Kassiou, M.; Dolle, F.

2011-01-01

Background: Many new candidate pharmaceuticals designed to improve recovery after stroke have been proposed recently, but there are still too few molecular imaging methods capable to assess their efficacy. A hallmark of the inflammatory reaction that follows focal cerebral ischemia is overexpression of the mitochondrial peripheral benzodiazepine receptor/18 kDa translocator protein (PBR/TSPO) in the monocytic lineage and astrocytes. This overexpression can be imaged with positron emission tomography (PET) using PBR/TSPO-selective radioligands such as [ 18 F]DPA-714. Purpose: Here, we tested whether PET with [ 18 F]DPA-714 would evidence the effect of minocycline, a broad spectrum antibiotic presently tested as neuro-protective agent after stroke, on the inflammatory reaction induced in an experimental model of stroke. Procedures: Ten rats were subjected to a 2-h transient middle cerebral artery occlusion with reperfusion. Minocycline or saline was intravenously administrated 1 h after reperfusion and daily during the following 6 days. PET studies were performed using [ 18 F]DPA-714 at 7 days after cerebral ischemia. Results: In vivo PET imaging showed a significant decrease in [ 18 F]DPA-714 uptake at 7 days after cerebral ischemia in rats treated with minocycline with respect to saline-treated animals. Minocycline treatment had no effect on the size of the infarcted area. Conclusion: Minocycline administered daily during 7 days after ischemia decreases [ 18 F]DPA- 714 binding, suggesting that the drug exerts an anti-inflammatory activity. [ 18 F]DPA-714 PET is a useful bio-marker to study novel anti-inflammatory strategies in experimental cerebral ischemia. (authors)

Heat treatment effects on impact toughness of 9Cr-1MoVNb and 12Cr-1MoVW steels irradiated to 100 dpa

Energy Technology Data Exchange (ETDEWEB)

Klueh, R.L.; Alexander, D.J. [Oak Ridge National Lab., TN (United States)

1997-08-01

Plates of 9Cr-1MoVNb and 12Cr-1MoVW steels were given four different heat treatments: two normalizing treatments were used and for each normalizing treatment two tempers were used. Miniature Charpy specimens from each heat treatment were irradiated to {approx}19.5 dpa at 365{degrees}C and to {approx}100 dpa at 420{degrees}C in the Fast Flux Test Facility (FFTF). In previous work, the same materials were irradiated to 4-5 dpa at 365{degrees}C and 35-36 dpa at 420{degrees}C in FFTF. The tests indicated that prior austenite grain size, which was varied by the different normalizing treatments, had a significant effect on impact behavior of the 9Cr-1MoVNb but not on the 12Cr-1MoVW. Tempering treatment had relatively little effect on the shift in DBTT for both steels. Conclusions are presented on how heat treatment can be used to optimize impact properties.

Heat treatment effects on impact toughness of 9Cr-1MoVNb and 12Cr-1MoVW steels irradiated to 100 dpa

International Nuclear Information System (INIS)

Klueh, R.L.; Alexander, D.J.

1997-01-01

Plates of 9Cr-1MoVNb and 12Cr-1MoVW steels were given four different heat treatments: two normalizing treatments were used and for each normalizing treatment two tempers were used. Miniature Charpy specimens from each heat treatment were irradiated to ∼19.5 dpa at 365 degrees C and to ∼100 dpa at 420 degrees C in the Fast Flux Test Facility (FFTF). In previous work, the same materials were irradiated to 4-5 dpa at 365 degrees C and 35-36 dpa at 420 degrees C in FFTF. The tests indicated that prior austenite grain size, which was varied by the different normalizing treatments, had a significant effect on impact behavior of the 9Cr-1MoVNb but not on the 12Cr-1MoVW. Tempering treatment had relatively little effect on the shift in DBTT for both steels. Conclusions are presented on how heat treatment can be used to optimize impact properties

Imaging of brain TSPO expression in a mouse model of amyotrophic lateral sclerosis with {sup 18}F-DPA-714 and micro-PET/CT

Energy Technology Data Exchange (ETDEWEB)

Gargiulo, S.; Gramanzini, M. [National Research Council, Institute of Biostructure and Bioimaging, Naples (Italy); Ceinge Biotecnologie Avanzate s.c. a r.l., Naples (Italy); Anzilotti, S.; Salvatore, M. [IRCCS SDN, Naples (Italy); Coda, A.R.D.; Panico, M.; Zannetti, A.; Vicidomini, C.; Quarantelli, M.; Pappata, S. [National Research Council, Institute of Biostructure and Bioimaging, Naples (Italy); Greco, A.; Brunetti, A. [University ' ' Federico II' ' , Department of Advanced Biomedical Sciences, Naples (Italy); Ceinge Biotecnologie Avanzate s.c. a r.l., Naples (Italy); Vinciguerra, A.; Pignataro, G. [University ' ' Federico II' ' , Division of Pharmacology, Department of Neuroscience, Reproductive and Dentistry Sciences, School of Medicine, Naples (Italy); Dolle, F. [CEA, Institute for Biomedical Imaging, Orsay (France); Annunziato, L. [University ' ' Federico II' ' , Division of Pharmacology, Department of Neuroscience, Reproductive and Dentistry Sciences, School of Medicine, Naples (Italy); IRCCS SDN, Naples (Italy)

2016-07-15

To evaluate the feasibility and sensitivity of {sup 18}F-DPA-714 for the study of microglial activation in the brain and spinal cord of transgenic SOD1{sup G93A} mice using high-resolution PET/CT and to evaluate the Iba1 and TSPO expression with immunohistochemistry. Nine symptomatic SOD1{sup G93A} mice (aged 117 ± 12.7 days, clinical score range 1 - 4) and five WT SOD1 control mice (aged 108 ± 28.5 days) underwent {sup 18}F-DPA-714 PET/CT. SUV ratios were calculated by normalizing the cerebellar (rCRB), brainstem (rBS), motor cortex (rMCX) and cervical spinal cord (rCSC) activities to that of the frontal association cortex. Two WT SOD1 and six symptomatic SOD1{sup G93A} mice were studied by immunohistochemistry. In the symptomatic SOD1{sup G93A} mice, rCRB, rBS and rCSC were increased as compared to the values in WT SOD1 mice, with a statistically significantly difference in rBS (2.340 ± 0.784 vs 1.576 ± 0.287, p = 0.014). Immunofluorescence studies showed that TSPO expression was increased in the trigeminal, facial, ambiguus and hypoglossal nuclei, as well as in the spinal cord, of symptomatic SOD1{sup G93A} mice and was colocalized with increased Iba1 staining. Increased {sup 18}F-DPA-714 uptake can be detected with high-resolution PET/CT in the brainstem of transgenic SOD1{sup G93A} mice, a region known to be a site of degeneration and increased microglial activation in amyotrophic lateral sclerosis, in agreement with increased TSPO expression in the brainstem nuclei shown by immunostaining. Therefore, {sup 18}F-DPA-714 PET/CT might be a suitable tool to evaluate microglial activation in the SOD1{sup G93A} mouse model. (orig.)

High mobility emissive organic semiconductor

Science.gov (United States)

Liu, Jie; Zhang, Hantang; Dong, Huanli; Meng, Lingqiang; Jiang, Longfeng; Jiang, Lang; Wang, Ying; Yu, Junsheng; Sun, Yanming; Hu, Wenping; Heeger, Alan J.

2015-01-01

The integration of high charge carrier mobility and high luminescence in an organic semiconductor is challenging. However, there is need of such materials for organic light-emitting transistors and organic electrically pumped lasers. Here we show a novel organic semiconductor, 2,6-diphenylanthracene (DPA), which exhibits not only high emission with single crystal absolute florescence quantum yield of 41.2% but also high charge carrier mobility with single crystal mobility of 34 cm2 V−1 s−1. Organic light-emitting diodes (OLEDs) based on DPA give pure blue emission with brightness up to 6,627 cd m−2 and turn-on voltage of 2.8 V. 2,6-Diphenylanthracene OLED arrays are successfully driven by DPA field-effect transistor arrays, demonstrating that DPA is a high mobility emissive organic semiconductor with potential in organic optoelectronics. PMID:26620323

EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA); Scientific Opinion related to the Tolerable Upper Intake Level of eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA) and docosapentaenoic acid (DPA)

DEFF Research Database (Denmark)

Tetens, Inge

Following a request from the European Commission, the Panel on Dietetic Products, Nutrition and Allergies was asked to deliver a scientific opinion on the Tolerable Upper Intake Level (UL) of the n-3 LCPUFAs eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA) and docosapentaenoic acid (DPA......). Available data are insufficient to establish a UL for n-3 LCPUFA (individually or combined) for any population group. At observed intake levels, consumption of n-3 LCPUFA has not been associated with adverse effects in healthy children or adults. Long-term supplemental intakes of EPA and DHA combined up...... to about 5 g/day do not appear to increase the risk of spontaneous bleeding episodes or bleeding complications, or affect glucose homeostasis immune function or lipid peroxidation, provided the oxidative stability of the n-3 LCPUFAs is guaranteed. Supplemental intakes of EPA and DHA combined at doses of 2...

Differences among KERMA or DPA data calculated from JENDL-4.0, ENDF/B-VII.1, JEFF-3.2 and FENDL-3.1b with NJOY

International Nuclear Information System (INIS)

Konno, C.

2016-01-01

KERMA factors and DPA cross-section data below 20 MeV in the official ACE files of JENDL-4.0, ENDF/B-VII.1, JEFF-3.2 and FENDL-3.1b were compared in detail. As a result, it was found out that the KERMA and DPA data of a lot of nuclei were different among the nuclear data libraries. Reasons of most of the differences were successfully categorized to the nuclear data and NJOY issues. The KERMA factors and DPA cross-section data in the ACE files with the problems should be revised. (author)

Neutron radiation damage studies in the structural materials of a 500 MWe fast breeder reactor using DPA cross-sections from ENDF / B-VII.1

Science.gov (United States)

Saha, Uttiyoarnab; Devan, K.; Bachchan, Abhitab; Pandikumar, G.; Ganesan, S.

2018-04-01

The radiation damage in the structural materials of a 500 MWe Indian prototype fast breeder reactor (PFBR) is re-assessed by computing the neutron displacement per atom (dpa) cross-sections from the recent nuclear data library evaluated by the USA, ENDF / B-VII.1, wherein revisions were taken place in the new evaluations of basic nuclear data because of using the state-of-the-art neutron cross-section experiments, nuclear model-based predictions and modern data evaluation techniques. An indigenous computer code, computation of radiation damage (CRaD), is developed at our centre to compute primary-knock-on atom (PKA) spectra and displacement cross-sections of materials both in point-wise and any chosen group structure from the evaluated nuclear data libraries. The new radiation damage model, athermal recombination-corrected displacement per atom (arc-dpa), developed based on molecular dynamics simulations is also incorporated in our study. This work is the result of our earlier initiatives to overcome some of the limitations experienced while using codes like RECOIL, SPECTER and NJOY 2016, to estimate radiation damage. Agreement of CRaD results with other codes and ASTM standard for Fe dpa cross-section is found good. The present estimate of total dpa in D-9 steel of PFBR necessitates renormalisation of experimental correlations of dpa and radiation damage to ensure consistency of damage prediction with ENDF / B-VII.1 library.

Imaging micro-glial/macrophage activation in spinal cords of experimental autoimmune encephalomyelitis rats by Positron Emission Tomography using the mitochondrial 18 kDa translocator protein radioligand [18F]DPA-714

International Nuclear Information System (INIS)

Abourbeh, Galith; Theze, Benoit; Dubois, Albertine; Tavitian, Bertrand; Boisgard, Raphael; Maroy, Renaud; Brulon, Vincent; Fontyn, Yoann; Dolle, Frederic

2012-01-01

Multiple sclerosis (MS) is an inflammatory demyelinating disease of the CNS. Activated micro-glia/macrophages play a key role in the immuno-pathogenesis of MS and its corresponding animal models, experimental autoimmune encephalomyelitis (EAE). Micro-glia activation begins at early stages of the disease and is associated with elevated expression of the 18 kDa mitochondrial translocator protein (TSPO). Thus, positron emission tomography (PET) imaging of micro-glial activation using TSPO-specific radioligands could be valuable for monitoring disease-associated neuro-inflammatory processes. EAE was induced in rats using a fragment of myelin basic protein, yielding acute clinical disease that reflects extensive spinal cord inflammation. Enhanced TSPO expression in spinal cords of EAE rats versus those of controls was confirmed by Western blot and immunohistochemistry. Biodistribution studies in control and EAE rats were performed using the TSPO radioligand [ 18 F]DPA-714 [N,N-diethyl-2-(2-(4-(2-fluoroethoxy)phenyl)-5,7-dimethylpyrazolo[1,5- a]pyrimidin-3-yl)acetamide]. At 1 h after injection, almost fivefold higher levels of [ 18 F]DPA-714 were measured in spinal cords of EAE rats versus controls. The specific binding of [ 18 F]DPA-714 to TSPO in spinal cords was confirmed in competition studies, using unlabeled (R,S)-PK11195 [(R,S)-N-methyl-N-(1-methylpropyl)-1-(2-chlorophenyl) - isoquinoline-3-carboxamide)] or DPA-714 in excess. MicroPET studies affirm that this differential radioactivity uptake in spinal cords of EAE versus control rats could be detected and quantified. Using [ 18 F]DPA-714, neuro-inflammation in spinal cords of EAE-induced rats could be visualized by PET, offering a sensitive technique for monitoring neuro-inflammatory lesions in the CNS and particularly in the spinal cord. In addition to current MRI protocols, this approach could provide molecular images of neuro-inflammation for detection, monitoring, and research in MS. (authors)

Irradiation testing of stainless steel plate material and weldments. Report on ITER Task T14, Part B. Tensile properties after 0.5 and 5 dpa at 350 and 500 K

International Nuclear Information System (INIS)

Rensman, J.W.; Boskeljon, J.; Horsten, M.G.; De Vries, M.I.

1997-10-01

The tensile properties of unirradiated and neutron irradiated type 316L(N)-SPH stainless steel plate, EB weldments, 16-8 TIG-weldments, and full 16-8 TIG-deposits have been measured. Miniature 4 mm diameter test specimens of the European Reference Heat 1 and 2 (ERH), and 4 mm and some 8 mm diameter specimens of the weldments mentioned above, were irradiated in the High Flux Reactor (HFR) in Petten, The Netherlands, simulating the first wall conditions by a combination of high displacement damage with high amounts of helium. The irradiation conditions were 0.5 and 5 displacements per atom (dpa) at 350K and 0.5 and 5 dpa at 500K. Testing temperatures ranged from 300K to 850K. This work was performed as part of the European Fusion Technology Programme for ITER as 'Irradiation testing of stainless steel' The report contains the experimental conditions and summarises the results. The tensile properties of the unirradiated ERH's 1 and 2 plate materials were found to differ slightly but significantly: ERH2 has a lower UTS, but higher yield strength and ductility than ERH1. The plate materials have lower yield strength in the unirradiated condition than all of the weldments (EB, TIG-weld and TIG-deposit), accompanied by a higher ductility of the plate materials. When irradiated at 350K the differences in strength between the plate and weld materials decrease, but the ductility of the plate remains higher than that of the weldments. A saturation of irradiation damage has taken place already at about 0.5 dpa. When irradiated at 500K the plate material continuously hardens up to 5 dpa, where it has lost all uniform plastic ductility. The weldments show similar but less dramatic hardening and loss of ductility as the plate material for both irradiation conditions. 54 figs., 17 tabs., 21 refs

Method for the Calculation of DPA in the Reactor Pressure Vessel of Atucha II

Directory of Open Access Journals (Sweden)

J. A. Mascitti

2011-01-01

It was determined that the maximum DPA rate in the RPV wall with fresh fuel element (FE is 3.76(3 × 10-12 s-1, it takes place in front of FEs BA42 and BL43, and it is symmetrical about the central channel, LG04, and LH03.

Swelling, mechanical properties, and microstructure of Type 316 stainless steel at fusion reactor damage levels

International Nuclear Information System (INIS)

Horak, J.A.; Bloom, E.E.; Grossbeck, M.L.; Maziasz, P.J.; Stiegler, J.O.; Wiffen, F.W.

1979-01-01

Alloys such as AISI 316 stainless steel exhibit more swelling and larger decreases in ductility when irradiated to produce fusion reactor He and dpa levels than at fast reactor He and dpa levels. For T approx. 0 C to ensure adequate ductility for long-term service

Direct high-pressure NMR observation of dipicolinic acid leaking from bacterial spore: A crucial step for thermal inactivation.

Science.gov (United States)

Akasaka, Kazuyuki; Maeno, Akihiro; Yamazaki, Akira

2017-12-01

A bacterial spore protects itself with an unusually high concentration (~10% in dry weight of spore) of dipicolinic acid (DPA), the release of which is considered the crucial step for inactivating it under mild pressure and temperature conditions. However, the process of how the spore releases DPA in response to pressure remains obscure. Here we apply 1 H high-resolution high-pressure NMR spectroscopy, for the first time, to the spore suspension of Bacillus subtilis natto and monitor directly and in real-time the leaking process of DPA in response to pressure of 200MPa at 20°C. We find that about one third of the total DPA leaks immediately upon applying pressure, but that the rest leaks slowly in hrs upon decreasing the pressure. Once DPA is fully released from the spore, the proteins of the spore become easily denatured at a mild temperature, e.g., 80°C, much below the temperature commonly used to inactivate spores (121°C). The success of the present experiment opens a new avenue for studying bacterial spores and cells at the molecular level in response to pressure, temperature and other perturbations. Copyright © 2017 Elsevier B.V. All rights reserved.

Microstructural response of titanium-modified austenitic stainless steels to neutron exposure of 70 dpa in FFTF/MOTA

International Nuclear Information System (INIS)

Katoh, Yutai; Kohno, Yutaka; Kohyama, Akira

1994-01-01

JPCA, a titanium-modified austenitic stainless steel, in solution-annealed or cold-worked condition and a compositionally modified JPCA in solution-annealed condition were examined by transmission electron microscopy following irradiation in FFTF/MOTA to an exposure level of up to about 70 dpa at 390 to 600 C. At lower temperatures, all the materials developed qualitatively similar cavity-, dislocation- and precipitate-microstructures. The lower-temperature swelling peak, which appeared at near 410 C, was more efficiently suppressed by phosphorus addition than cold-working. Irradiation at or above 520 C produced substantially large swelling in solution-annealed JPCA. The cavities contributed to this higher-temperature swelling developed in association with M 6 C-type precipitates. Neither cavities other than very small helium bubbles nor massive particles of M 6 C-type precipitates were observed in cold-worked and phosphorus-modified materials, in which MC-type precipitates developed at very high concentration. The effect of pre-irradiation microstructure and compositional modification on the behavior of these precipitates is discussed. ((orig.))

[18F]DPA 714 PET Imaging Reveals Global Neuroinflammation in Zika Virus Infected Mice

Science.gov (United States)

2017-09-12

with neurotropic viruses and the evaluation of therapeutics being developed for treatment of infectious diseases. Keywords: Zika virus , Animal...18F]DPA-714 PET Imaging Reveals Global Neuroinflammation in Zika Virus - Infected Mice Kyle Kuszpit1†, Bradley S. Hollidge2†, Xiankun Zeng3, Robert...Running Head: PET Imaging of Zika Virus -Induced Neuroinflammation Manuscript Category: Article Affiliations: 1Molecular and Translational

Engineering [Ln(DPA){sub 3}]{sup 3-} binding sites in proteins: a widely applicable method for tagging proteins with lanthanide ions

Energy Technology Data Exchange (ETDEWEB)

Jia Xinying; Yagi, Hiromasa; Su Xuncheng; Stanton-Cook, Mitchell; Huber, Thomas; Otting, Gottfried, E-mail: gottfried.otting@anu.edu.au [Australian National University, Research School of Chemistry (Australia)

2011-08-15

Paramagnetic relaxation enhancements from unpaired electrons observed in nuclear magnetic resonance (NMR) spectra present powerful long-range distance restraints. The most frequently used paramagnetic tags, however, are tethered to the protein via disulfide bonds, requiring proteins with single cysteine residues for covalent attachment. Here we present a straightforward strategy to tag proteins site-specifically with paramagnetic lanthanides without a tether and independent of cysteine residues. It relies on preferential binding of the complex between three dipicolinic acid molecules (DPA) and a lanthanide ion (Ln{sup 3+}), [Ln(DPA){sub 3}]{sup 3-}, to a pair of positively charged amino acids whose charges are not compensated by negatively charged residues nearby. This situation rarely occurs in wild-type proteins, allowing the creation of specific binding sites simply by introduction of positively charged residues that are positioned far from glutamate or aspartate residues. The concept is demonstrated with the hnRNPLL RRM1 domain. In addition, we show that histidine- and arginine-tags present binding sites for [Ln(DPA){sub 3}]{sup 3-}.

Mechanical property and conductivity changes in several copper alloys after 13.5 dpa neutron irradiation

International Nuclear Information System (INIS)

Ames, M.; Kohse, G.; Lee, T.S.; Grant, N.J.; Harling, O.K.

1986-01-01

A scoping experiment in which 25 different copper materials of 17 alloy compositions were irradiated to approx.13.5 dpa approx.400 0 C in a fast reactor is described. The materials include rapidly solidified (RS) alloys, with and without oxide dispersion strengthening, as well as conventionally processed alloys. Immersion density (swelling), electrical conductivity (which can be related to thermal conductivity), and yield stress and ductility by miniature disk bend testing have been measured before and after irradiation. It was found, in general, that the Rs alloys are stable under irradiation to 13.5 dpa, showing small conductivity changes and little or no swelling. Reduction of strength and ductility, in post-irradiation tests at the irradiation temperature, are not generally observed. Some conventionally processed alloys also performed well, although irradiation softening and swelling of several percent were observed in some cases, and pure copper swelled in excess of 5%. It is concluded that a number of copper alloys should receive further study, and that higher dose irradiations will be required to establish the limits of swelling suppression in these alloys

Post irradiation examination of RAF/M steels after fast reactor irradiation up to 33 dpa and < 340 C (ARBOR1). RAFM steels. Metallurgical and mechanical characterisation. Final report for TW2-TTMS-001b, D9

Energy Technology Data Exchange (ETDEWEB)

Petersen, C. [Forschungszentrum Karlsruhe GmbH Technik und Umwelt (Germany). EURATOM, Inst. fuer Materialforschung, Programm Kernfusion

2010-07-01

In an energy generating fusion reactor structural materials will be exposed to very high dpa-levels of about 100 dpa. Due to this fact and because fast reactor irradiation facilities in Europe are not available anymore, a reactor irradiation at the State Scientific Center of the Russian Federation with its Research Institute of Atomic Reactors (SSC RIAR), Dimitrovgrad, had been performed in the fast reactor BOR 60 with an instrumented test rig. This test rig contained tensile, impact and Low Cycle Fatigue type specimens used at FZK since many years. Samples of actual Reduced Activation Ferritic/Martensitic (RAF/M) -steels (e.g. EUROFER 97) had been irradiated in this reactor at a lower temperature (< 340 C) up to a damage of 33 dpa. This irradiation campaign was called ARBOR 1. Starting in 2003 one half of these irradiated samples were post irradiation examined (PIE) by tensile testing, low cycle fatigue testing and impact testing under the ISTC Partner Contract 2781p in the hot cells of SSC RIAR. In the post irradiation instrumented impact tests a significant increase in the Ductile to Brittle Transition Temperature as an effect of irradiation has been detected. During tensile testing the strength values are increasing and the strain values reduced due to substantial irradiation hardening. The hardening rate is decreasing with increasing damage level, but it does not show saturation. The low cycle fatigue behaviour of all examined RAF/M - steels show at total strain amplitudes below 1 % an increase of number of cycles to failure, due to irradiation hardening. From these post irradiation experiments, like tensile, low cycle fatigue and impact tests, radiation induced design data, e.g. for verification of design codes, can be generated.

Brain energy metabolism and neuroinflammation in ageing APP/PS1-21 mice using longitudinal 18F-FDG and 18F-DPA-714 PET imaging.

Science.gov (United States)

Takkinen, Jatta S; López-Picón, Francisco R; Al Majidi, Rana; Eskola, Olli; Krzyczmonik, Anna; Keller, Thomas; Löyttyniemi, Eliisa; Solin, Olof; Rinne, Juha O; Haaparanta-Solin, Merja

2017-08-01

Preclinical animal model studies of brain energy metabolism and neuroinflammation in Alzheimer's disease have produced conflicting results, hampering both the elucidation of the underlying disease mechanism and the development of effective Alzheimer's disease therapies. Here, we aimed to quantify the relationship between brain energy metabolism and neuroinflammation in the APP/PS1-21 transgenic mouse model of Alzheimer's disease using longitudinal in vivo 18 F-FDG and 18 F-DPA-714) PET imaging and ex vivo brain autoradiography. APP/PS1-21 (TG, n = 9) and wild type control mice (WT, n = 9) were studied longitudinally every third month from age 6 to 15 months with 18 F-FDG and 18 F-DPA-714 with a one-week interval between the scans. Additional TG (n = 52) and WT (n = 29) mice were used for ex vivo studies. In vivo, the 18 F-FDG SUVs were lower and the 18 F-DPA-714 binding ratios relative to the cerebellum were higher in the TG mouse cortex and hippocampus than in WT mice at age 12 to 15 months ( p < 0.05). The ex vivo cerebellum binding ratios supported the results of the in vivo 18 F-DPA-714 studies but not the 18 F-FDG studies. This longitudinal PET study demonstrated decreased energy metabolism and increased inflammation in the brains of APP/PS1-21 mice compared to WT mice.

PIE of nuclear grade SiC/SiC flexural coupons irradiated to 10 dpa at LWR temperature

Energy Technology Data Exchange (ETDEWEB)

Koyanagi, Takaaki [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Katoh, Yutai [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

2017-03-01

Silicon carbide fiber-reinforced SiC matrix (SiC/SiC) composites are being actively investigated for accident-tolerant core structures of light water reactors (LWRs). Owing to the limited number of irradiation studies previously conducted at LWR-coolant temperature, this study examined SiC/SiC composites following neutron irradiation at 230–340°C to 2.0 and 11.8 dpa in the High Flux Isotope Reactor. The investigated materials are chemical vapor infiltrated (CVI) SiC/SiC composites with three different reinforcement fibers. The fiber materials were monolayer pyrolytic carbon (PyC)-coated Hi-NicalonTM Type-S (HNS), TyrannoTM SA3 (SA3), and SCS-Ultra^TM (SCS) SiC fibers. The irradiation resistance of these composites was investigated based on flexural behavior, dynamic Young’s modulus, swelling, and microstructures. There was no notable mechanical properties degradation of the irradiated HNS and SA3 SiC/SiC composites except for reduction of the Young’s moduli by up to 18%. The microstructural stability of these composites supported the absence of degradation. In addition, no progressive swelling from 2.0 to 11.8 dpa was confirmed for these composites. On the other hand, the SCS composite showed significant mechanical degradation associated with cracking within the fiber. This study determined that SiC/SiC composites with HNS or SA3 SiC/SiC fibers, a PyC interphase, and a CVI SiC matrix retain their properties beyond the lifetime dose for LWR fuel cladding at the relevant temperature.

Quantitation of bone mineral by dual photon absorptiometry (DPA): Evaluation of instrument performance

International Nuclear Information System (INIS)

Dunn, W.L.; O'Duffy, A.; Wahner, H.W.

1984-01-01

Quantitation of bone mineral is used with increasing frequency for clinical studies. This paper details the principle of DPA and present an evaluation of the technique. DPA measurements were performed with a scanning dual photon system constructed at this institution and modeled after the device developed at the University of Wisconsin. The components are a rectilinear scanner frame, 1.5 Ci Gd-153 source, NaI(TL) detector and a PDP 11/03 computer. Dual discriminator windows are set on the 44 and 100 keV photon energies of Gd-153. Instrument linearity, accuracy and reproducibility were evaluated with ashed bone standards and simulated tissue covering. In these experiments computed and actual bone mineral have a correlation coefficient of 1.0 and a SEE of approximately 1.0% (Linear regression analysis). Precision and accuracy of a standard were studied over a period of two years. Mean error between actual and measured bone mineral was 0.28%. In vivo precision in six subjects averaged 2.3% (CV) for lumbar spine measurements. The effect of soft tissue compositional change was studied with ashed bone standards and human cadaver spine specimens. Intraosseous fat changes of 50% produced an average bone mineral measurement error of 1.4%. A 20% change in fat thickness produced a 2.5% error. In situ and in vitro scans of 9 cadaver spines were performed to study the effect of extraosseous fat. The mean percent difference between the two measurements was 0.7% (SEE=3.2%)

Response of solute and precipitation-strengthened copper alloys at high neutron exposure

International Nuclear Information System (INIS)

Garner, F.A.; Hamilton, M.L.; Shikama, T.; Edwards, D.J.; Newkirk, J.W.

1991-11-01

A variety of solute and precipitation strengthened copper base alloys have been irradiated to neutron-induced displacement levels of 34 to 150 dpa at 415 degrees C and 32 dpa at 529 degrees C in the Fast Flux Test Facility to assess their potential for high heat flux applications in fusion reactors. Several MZC-type alloys appear to offer the most promise for further study. For low fluence applications CuBeNi and spinodally strengthened CuNiTi alloys may also be suitable. Although Cu-2Be resists swelling, it is not recommended for fusion reactor applications because of its low conductivity

Response of solute and precipitation-strengthened copper alloys at high neutron exposure

Energy Technology Data Exchange (ETDEWEB)

Garner, F.A.; Hamilton, M.L. [Pacific Northwest Lab., Richland, WA (United States); Shikama, T. [Tohoku Univ., Oarai Branch (Japan); Edwards, D.J.; Newkirk, J.W. [Missouri Univ., Rolla, MO (United States)

1991-11-01

A variety of solute and precipitation strengthened copper base alloys have been irradiated to neutron-induced displacement levels of 34 to 150 dpa at 415{degrees}C and 32 dpa at 529{degrees}C in the Fast Flux Test Facility to assess their potential for high heat flux applications in fusion reactors. Several MZC-type alloys appear to offer the most promise for further study. For low fluence applications CuBeNi and spinodally strengthened CuNiTi alloys may also be suitable. Although Cu-2Be resists swelling, it is not recommended for fusion reactor applications because of its low conductivity.

A new and unusual deformation behavior observed in 12Cr18Ni10Ti stainless steel irradiated at 307 deg. C to 55 dpa in BN-350

International Nuclear Information System (INIS)

Gusev, M.; Maksimkin, O.; Osipov, I.S.; Garner, F.

2007-01-01

Full text of publication follows: It is currently accepted that neutron irradiation of stainless steels in general leads to increased strength, reduction of ductility and inevitably to embrittlement. The microstructural origins of such changes in mechanical behavior are well understood. Occasionally, however, a new phenomenon is observed at higher fluences. Void-induced embrittlement is an example whereby the ductility loss is strongly accelerated when new microstructural conditions develop from voids that cause stress concentration, removal of nickel from the matrix and thereby induce a martensitic transformation. This process occurs at moderately high temperatures where high void swelling can occur. It now appears that there is another, previously unobserved phenomenon that develops in austenitic steel irradiated to relatively high dose and relatively low temperature. In this case, however, the loss of plasticity commonly developed at lower dose is reversed and is replaced by an unusually high deformation. The plastic deformation was studied of miniature flat tensile specimens of 12Cr18Ni10Ti austenitic steel cut from a fuel assembly wrapper irradiated in the BN-350 reactor to 55 dpa at 580 K (307 deg. C). A new optical extensometry technique was employed that uses a video camera and multiple tiny markers painted on the specimen, allowing visualization and recording of the strain distribution as it develops along the specimen. The total deformation derived from the engineering diagrams for these specimens was 35-40%, while 3-7% was expected from previous studies conducted at lower dpa levels. The video record showed that the material resists necking and involves a moving deformation wave that initiates near one of the tensile grippers and spreads along ∼3/4 of the gauge length before failure occurs. Such behavior, often called a 'moving neck' has been observed previously in pure iron and Al-Mg alloys but has not been observed in irradiated stainless steels

Continuous gradient temperature Raman spectroscopy of n-6 DPA and DHA from -100 C to 20°C

Science.gov (United States)

One of the great unanswered questions with respect to biological science in general is the absolute necessity of DHA in fast signal processing tissues. N-6 DPA, with just one less diene, group, is fairly abundant in terrestrial food chains yet cannot substitute for DHA. Gradient Temperature Raman sp...

Red Blood Cell Docosapentaenoic Acid (DPA n-3) is Inversely Associated with Triglycerides and C-reactive Protein (CRP) in Healthy Adults and Dose-Dependently Increases Following n-3 Fatty Acid Supplementation

Science.gov (United States)

Skulas-Ray, Ann C.; Flock, Michael R.; Richter, Chesney K.; Harris, William S.; West, Sheila G.; Kris-Etherton, Penny M.

2015-01-01

The role of the long-chain omega-3 (n-3) fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in lipid metabolism and inflammation has been extensively studied; however, little is known about the relationship between docosapentaenoic acid (DPA, 22:5 n-3) and inflammation and triglycerides (TG). We evaluated whether n-3 DPA content of red blood cells (RBC) was associated with markers of inflammation (interleukin-6 (IL-6), tumor necrosis factor α (TNF-α), and C-reactive protein (CRP) and fasting TG prior to n-3 supplementation in two studies (Study 1: n = 115, aged 20–44 years, body mass index (BMI) 20–30 kg/m2, TG = 34–176 mg/dL; Study 2: n = 28, aged 22–65 years, BMI 24–37 kg/m2, TG = 141–339 mg/dL). We also characterized the dose-response effects of n-3 fatty acid supplementation on RBC n-3 DPA after five months of supplementation with fish oil (Study 1: 0, 300, 600, 900, and 1800 mg/day EPA + DHA) and eight weeks of prescription n-3 ethyl esters (Study 2: 0, 850, and 3400 mg/day EPA + DHA). In Study 1, RBC n-3 DPA was inversely correlated with CRP (R2 = 36%, p < 0.001) and with fasting TG (r = −0.30, p = 0.001). The latter finding was replicated in Study 2 (r = −0.33, p = 0.04). In both studies, n-3 supplementation significantly increased RBC n-3 DPA dose-dependently. Relative increases were greater for Study 1, with increases of 29%–61% vs. 14%–26% for Study 2. The associations between RBC n-3 DPA, CRP, and fasting TG may have important implications for the prevention of atherosclerosis and chronic inflammatory diseases and warrant further study. PMID:26247967

Important comments on KERMA factors and DPA cross-section data in ACE files of JENDL-4.0, JEFF-3.2 and ENDF/B-VII.1

Science.gov (United States)

Konno, Chikara; Tada, Kenichi; Kwon, Saerom; Ohta, Masayuki; Sato, Satoshi

2017-09-01

We have studied reasons of differences of KERMA factors and DPA cross-section data among nuclear data libraries. Here the KERMA factors and DPA cross-section data included in the official ACE files of JENDL-4.0, ENDF/B-VII.1 and JEFF-3.2 are examined in more detail. As a result, it is newly found out that the KERMA factors and DPA cross-section data of a lot of nuclei are different among JENDL-4.0, ENDF/B-VII.1 and JEFF-3.2 and reasons of the differences are the followings: 1) large secondary particle production yield, 2) no secondary gamma data, 3) secondary gamma data in files12-15 mt = 3, 4) mt = 103-107 data without mt = 600 s-800 s data in file6. The issue 1) is considered to be due to nuclear data, while the issues 2)-4) seem to be due to NJOY. The ACE files of JENDL-4.0, ENDF/B-VII.1 and JEFF-3.2 with these problems should be revised after correcting wrong nuclear data and NJOY problems.

Formation of austenite in high Cr ferritic/martensitic steels by high fluence neutron irradiation

Science.gov (United States)

Lu, Z.; Faulkner, R. G.; Morgan, T. S.

2008-12-01

High Cr ferritic/martensitic steels are leading candidates for structural components of future fusion reactors and new generation fission reactors due to their excellent swelling resistance and thermal properties. A commercial grade 12%CrMoVNb ferritic/martensitic stainless steel in the form of parent plate and off-normal weld materials was fast neutron irradiated up to 33 dpa (1.1 × 10 -6 dpa/s) at 400 °C and 28 dpa (1.7 × 10 -6 dpa/s) at 465 °C, respectively. TEM investigation shows that the fully martensitic weld metal transformed to a duplex austenite/ferrite structure due to high fluence neutron irradiation, the austenite was heavily voided (˜15 vol.%) and the ferrite was relatively void-free; whilst no austenite phases were detected in plate steel. Thermodynamic and phase equilibria software MTDATA has been employed for the first time to investigate neutron irradiation-induced phase transformations. The neutron irradiation effect is introduced by adding additional Gibbs free energy into the system. This additional energy is produced by high energy neutron irradiation and can be estimated from the increased dislocation loop density caused by irradiation. Modelling results show that neutron irradiation reduces the ferrite/austenite transformation temperature, especially for high Ni weld metal. The calculated results exhibit good agreement with experimental observation.

User interface tool based on the MCCM for the calculation of dpa distributions

International Nuclear Information System (INIS)

Pinnera, I.; Cruz, C.; Abreu, Y.; Leyva, A.

2009-01-01

The Monte Carlo assisted Classical Method (MCCM) was introduced by the authors to calculate the displacements per atom (dpa) distributions in solid materials, making use of the standard outputs of simulation code system MCNP and the classical theories of electron elastic scattering. Based on this method a new DLL with several user interface functions was implemented. Then, an application running on Windows systems was development in order to allow the easy handle of different useful functionalities included on it. In the present work this application is presented and some examples of it successful use in different interesting materials are exposed. (Author)

The effect of irradiation on the stability and properties of monolithic silicon carbide and SiCf/SiC composites up to 25 dpa

International Nuclear Information System (INIS)

Hollenberg, G.W.; Henager, C.H. Jr.; Youngblood, G.E.; Trimble, D.J.; Simonson, S.A.; Newsome, G.A.; Lewis, E.

1994-04-01

Stability and properties of monolithic and SiC f /SiC composites were measured before and after irradiation in a fast neutron spectrum up to 25 dpa between 500 and 1500C. Dimensional changes were relatively consistent with previous investigations. Strength and modulus of SiC f /SiC composites decreased after irradiation as a result of fiber/matrix decoupling. For some composites, uniform elongation was not significantly degraded by irradiation. Thermal conductivity also decreased after irradiation at low temperatures because of the introduction of lattice defects as phonon scattering sites. Retention of properties under the severe conditions of 25 dpa and 800C suggests that a composite tailored for neutron damage resistance can be developed

Microchemical and microstructural evolution of AISI 304 stainless steel irradiated in EBR-II at PWR-relevant dpa rates

Energy Technology Data Exchange (ETDEWEB)

Dong, Y. [Department of Materials Science and Engineering, University of Michigan, Ann Arbor, MI 48109 (United States); Sencer, B.H. [Idaho National Laboratory, Idaho Falls, ID 83402 (United States); Garner, F.A. [Radiation Effects Consulting, Richland, WA 99354 (United States); Marquis, E.A., E-mail: emarq@umich.edu [Department of Materials Science and Engineering, University of Michigan, Ann Arbor, MI 48109 (United States)

2015-12-15

AISI 304 stainless steel was irradiated at 416 °C and 450 °C at a 4.4 × 10{sup −9} and 3.05 × 10{sup −7} dpa/s to ∼0.4 and ∼28 dpa, respectively, in the reflector of the EBR-II fast reactor. Both unirradiated and irradiated conditions were examined using standard and scanning transmission electron microscopy, energy dispersive spectroscopy, and atom probe tomography on very small specimens produced by focused ion beam milling. These results are compared with previous electron microscopy examination of 3 mm disks from essentially the same material. By comparing a very low dose specimen with a much higher dose specimen, both derived from a single reactor assembly, it has been demonstrated that the coupled microstructural and microchemical evolution of dislocation loops and other sinks begins very early, with elemental segregation producing at these sinks what appears to be measurable precursors to fully formed precipitates found at higher doses. The nature of these sinks and their possible precursors are examined in detail.

Microchemical and microstructural evolution of AISI 304 stainless steel irradiated in EBR-II at PWR-relevant dpa rates

Science.gov (United States)

Dong, Y.; Sencer, B. H.; Garner, F. A.; Marquis, E. A.

2015-12-01

AISI 304 stainless steel was irradiated at 416 °C and 450 °C at a 4.4 × 10-9 and 3.05 × 10-7 dpa/s to ∼0.4 and ∼28 dpa, respectively, in the reflector of the EBR-II fast reactor. Both unirradiated and irradiated conditions were examined using standard and scanning transmission electron microscopy, energy dispersive spectroscopy, and atom probe tomography on very small specimens produced by focused ion beam milling. These results are compared with previous electron microscopy examination of 3 mm disks from essentially the same material. By comparing a very low dose specimen with a much higher dose specimen, both derived from a single reactor assembly, it has been demonstrated that the coupled microstructural and microchemical evolution of dislocation loops and other sinks begins very early, with elemental segregation producing at these sinks what appears to be measurable precursors to fully formed precipitates found at higher doses. The nature of these sinks and their possible precursors are examined in detail.

Effect on fast neutron irradiation to 4 dpa at 400{degrees}C on the properties of V-(4-5)Cr-(4-5)Ti alloys

Energy Technology Data Exchange (ETDEWEB)

Zinkle, S.J.; Alexander, D.J.; Robertson, J.P. [Oak Ridge National Lab., TN (United States)] [and others

1997-04-01

Tensile, Charpy impact and electrical resistivity measurements have been performed at ORNL on V-4Cr-4Ti and V-5Cr-5Ti specimens that were prepared at ANL and irradiated in the lithium-bonded X530 experiment in the EBR-II fast reactor. All of the specimens were irradiated to a damage level of about 4 dpa at a temperature of {approximately}400{degrees}C. A significant amount of radiation hardening was evident in both the tensile and Charpy impact tests. The irradiated V-4Cr-4Ti yield strength measured at {approximately}390{degrees}C was >800 MPa, which is more than three times as high as the unirradiated value. The uniform elongations of the irradiated tensile specimens were typically {approximately}1%, with corresponding total elongations of 4-6%. The ductile to brittle transition temperature of the irradiated specimens was less than the unirradiated resistivity, which suggests that hardening associated with interstitial solute pickup was minimal.

Increased dipicolinic acid production with an enhanced spoVF operon in Bacillus subtilis and medium optimization.

Science.gov (United States)

Takahashi, Fumikazu; Sumitomo, Nobuyuki; Hagihara, Hiroshi; Ozaki, Katsuya

2015-01-01

Dipicolinic acid (DPA) is a multi-functional agent for cosmetics, antimicrobial products, detergents, and functional polymers. The aim of this study was to design a new method for producing DPA from renewable material. The Bacillus subtilis spoVF operon encodes enzymes for DPA synthase and the part of lysine biosynthetic pathway. However, DPA is only synthesized in the sporulation phase, so the productivity of DPA is low level. Here, we report that DPA synthase was expressed in vegetative cells, and DPA was produced in the culture medium by replacement of the spoVFA promoter with other highly expressed promoter in B. subtilis vegetative cells, such as spoVG promoter. DPA levels were increased in the culture medium of genetically modified strains. DPA productivity was significantly improved up to 29.14 g/L in 72 h culture by improving the medium composition using a two-step optimization technique with the Taguchi methodology.

Preliminary study on DPA cross-section of 184W in JEFF-3.2

International Nuclear Information System (INIS)

Konno, C.

2016-01-01

I investigated reasons why the DPA cross-section data of JEFF-3.2 184 W was too large above 30 MeV. As a result, I found out that the production yield of 182Ta in mf6 mt5 in JEFF-3.2 184W was too large and demonstrated that the problem was solved if the production yield of 182 Ta was modified. I picked out that the same issue also occurred in 182W, 183W and 186W. The production yield data of all the tungsten isotopes in JEFF-3.2 should be reconfirmed and revised if they have mistakes. (author)

Levels of small molecules and enzymes in the mother cell compartment and the forespore of sporulating Bacillus megaterium.

Science.gov (United States)

Singh, R P; Setlow, B; Setlow, P

1977-06-01

We have determined the amounts of a number of small molecules and enzymes in the mother cell compartment and the developing forespore during sporulation of Bacillus megaterium. Significant amounts of adenosine 5'-triphosphate and reduced nicotinamide adenine dinucleotide were present in the forespore compartment before accumulation of dipicolinic acid (DPA), but these compounds disappeared as DPA was accumulated. 3-Phosphoglyceric acid (3-PGA) accumulated only within the developing forespore, beginning 1 to 2 h before DPA accumulation. Throughout its development the forespore contained constant levels of enzymes of both 3-PGA synthesis (phosphoglycerate kinase and glyceraldehyde-3-phosphate dehydrogenase) and 3-PGA utilization (phosphoglycerate mutase, enolase, and pyruvate kinase) at levels similar to those in the mother cell and the dormant spore. Despite the presence of enzymes for 3-PGA utilization, this compound was stable within isolated forespores. Two acid-soluble proteins (A and B proteins) also accumulated only in the forespore, beginning 1 to 2 h before DPA accumulation. At this time the specific protease involved in degradation of the A and B proteins during germination also appeared, but only in the forespore compartment. Nevertheless, the A and B proteins were stable within isolated forespores. Arginine and glutamic acid accumulated within the forespore in parallel with DPA accumulation. The forespore also contained the enzyme arginase at a level similar to that in the mother cell and a level of glutamic acid decarboxylase 2- to 25-fold higher than that in the mother cell, depending on when in sporulation the forespores were isolated. The specific activities of several other enzymes (protease active on hemoglobin, ornithine transcarbamylase, malate dehydrogenase, aconitase, and isocitrate dehydrogenase) in forespores were about 10% or less of the values in the mother cell. Aminopeptidase was present at similar levels in both compartments; threonine

Level of daily physical activity in chronic obstructive pulmonary disease (COPD) patients according to GOLD classification.

Science.gov (United States)

Rodó-Pin, Anna; Balañá, Ana; Molina, Lluís; Gea, Joaquim; Rodríguez, Diego A

2017-02-09

The Global Initiative for Chronic Obstructive Lung Disease (GOLD guideline) for patients with chronic obstructive pulmonary disease does not adequately reflect the impact of the disease because does not take into account daily physical activity (DPA). Forty eight patients (12 in each GOLD group) were prospectively recruited. DPA was evaluated by accelerometer. Patients were classified into 3 levels of activity (very inactive, sedentary, active). No significant differences in levels of physical activity among GOLD groups (P=.361) were observed. The percentages of very inactive patients were 33% in group A, 42% in group B, 42% in group C and 59% in group D. In addition, high percentage of sedentary patients were observed through 4 groups, in group A (50%), B and C (42%, each), and group D (41%). COPD patients has very low levels of physical activity at all stages of GOLD classification even those defined as low impact (such as GOLD A). Is necessary to detect patients at risk who might benefit from specific interventions. Copyright © 2016 Elsevier España, S.L.U. All rights reserved.

High temperature tensile testing of modified 9Cr-1Mo after irradiation with high energy protons

International Nuclear Information System (INIS)

Toloczko, M.B.; Hamilton, M.L.; Maloy, S.A.

2003-01-01

This study examines the effect of tensile test temperatures ranging from 50 to 600 deg. C on the tensile properties of a modified 9Cr-1Mo ferritic steel after high energy proton irradiation at about 35-67 deg. C to doses from 1 to 3 dpa and 9 dpa. For the specimens irradiated to doses between 1 and 3 dpa, it was observed that the yield strength and ultimate strength decreased monotonically as a function of tensile test temperature, whereas the uniform elongation (UE) remained at approximately 1% for tensile test temperatures up to 250 deg. C and then increased for tensile test temperatures up to and including 500 deg. C. At 600 deg. C, the UE was observed to be less than the values at 400 and 500 deg. C. UE of the irradiated material tensile tested at 400-600 deg. C was observed to be greater than the values for the unirradiated material at the same temperatures. Tensile tests on the 9 dpa specimens followed similar trends

Carvacrol suppresses high pressure high temperature inactivation of Bacillus cereus spores.

Science.gov (United States)

Luu-Thi, Hue; Corthouts, Jorinde; Passaris, Ioannis; Grauwet, Tara; Aertsen, Abram; Hendrickx, Marc; Michiels, Chris W

2015-03-16

The inactivation of bacterial spores generally proceeds faster and at lower temperatures when heat treatments are conducted under high pressure, and high pressure high temperature (HPHT) processing is, therefore, receiving an increased interest from food processors. However, the mechanisms of spore inactivation by HPHT treatment are poorly understood, particularly at moderately elevated temperature. In the current work, we studied inactivation of the spores of Bacillus cereus F4430/73 by HPHT treatment for 5 min at 600MPa in the temperature range of 50-100°C, using temperature increments of 5°C. Additionally, we investigated the effect of the natural antimicrobial carvacrol on spore germination and inactivation under these conditions. Spore inactivation by HPHT was less than about 1 log unit at 50 to 70°C, but gradually increased at higher temperatures up to about 5 log units at 100°C. DPA release and loss of spore refractility in the spore population were higher at moderate (≤65°C) than at high (≥70°C) treatment temperatures, and we propose that moderate conditions induced the normal physiological pathway of spore germination resulting in fully hydrated spores, while at higher temperatures this pathway was suppressed and replaced by another mechanism of pressure-induced dipicolinic acid (DPA) release that results only in partial spore rehydration, probably because spore cortex hydrolysis is inhibited. Carvacrol strongly suppressed DPA release and spore rehydration during HPHT treatment at ≤65°C and also partly inhibited DPA release at ≥65°C. Concomitantly, HPHT spore inactivation was reduced by carvacrol at 65-90°C but unaffected at 95-100°C. Copyright © 2014 Elsevier B.V. All rights reserved.

Red Blood Cell Docosapentaenoic Acid (DPA n-3) is Inversely Associated with Triglycerides and C-reactive Protein (CRP) in Healthy Adults and Dose-Dependently Increases Following n-3 Fatty Acid Supplementation

OpenAIRE

Skulas-Ray, Ann C.; Flock, Michael R.; Richter, Chesney K.; Harris, William S.; West, Sheila G.; Kris-Etherton, Penny M.

2015-01-01

The role of the long-chain omega-3 (n-3) fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in lipid metabolism and inflammation has been extensively studied; however, little is known about the relationship between docosapentaenoic acid (DPA, 22:5 n-3) and inflammation and triglycerides (TG). We evaluated whether n-3 DPA content of red blood cells (RBC) was associated with markers of inflammation (interleukin-6 (IL-6), tumor necrosis factor α (TNF-α), and C-reactive protei...

Standard Practice for Characterizing Neutron Exposures in Iron and Low Alloy Steels in Terms of Displacements Per Atom (DPA), E 706(ID)

CERN Document Server

American Society for Testing and Materials. Philadelphia

2001-01-01

1.1 This practice describes a standard procedure for characterizing neutron irradiations of iron (and low alloy steels) in terms of the exposure index displacements per atom (dpa) for iron. 1.2 Although the general procedures of this practice apply to any material for which a displacement cross section d(E) is known (see Practice E 521), this practice is written specifically for iron. 1.3 It is assumed that the displacement cross section for iron is an adequate approximation for calculating displacements in steels that are mostly iron (95 to 100 %) in radiation fields for which secondary damage processes are not important. 1.4 Procedures analogous to this one can be formulated for calculating dpa in charged particle irradiations. (See Practice E 521.) 1.5 The application of this practice requires knowledge of the total neutron fluence and flux spectrum. Refer to Practice E 521 for determining these quantities. 1.6 The correlation of radiation effects data is beyond the scope of this practice. This stand...

Continuous gradient temperature Raman spectroscopy and differential scanning calorimetry of N-3DPA and DHA from -100 to 10°C

Science.gov (United States)

Docosahexaenoic acid (DHA, 22:6n-3) is exclusively utilized in fast signal processing tissues such as retinal, neural and cardiac. N-3 docosapentaenoic acid (n-3DPA, 22:5n-3), with just one less double bond, is also found in the marine food chain yet cannot substitute for DHA. Gradient Temperature R...

Tensile behavior of EUROFER ODS steel after neutron irradiation up to 16.3 dpa between 250 and 450 °C

International Nuclear Information System (INIS)

Materna-Morris, Edeltraud; Lindau, Rainer; Schneider, Hans-Christian; Möslang, Anton

2015-01-01

Highlights: • The first 9%CrWVTa steel (0.5% Y_2O_3), EUROFER ODS HIP, have been neutron irradiated up to 16.3 dpa, between 250 and 450 °C, in the High Flux Reactor (HFR). • After post-irradiation tensile tests, there was not any increase of the upper yield strength or strain localization after irradiation which is typical of RAFM steels. • Initially higher yield strength, R_p_0_._2, and distinctive tensile strength, R_m, of EUROFER ODS HIP compared to EUROFER97 steel. • These values increased due to the neutron irradiation at lower irradiation temperatures. - Abstract: During the development of structural material for future fusion reactors, a 50 kg heat of reduced-activation ferritic-martensitic 9%CrWVTa steel with nanoscaled Y_2O_3-particles, EUROFER97 ODS HIP, was produced using powder metallurgy fabrication technology. This first batch of EUROFER97 ODS HIP and, for comparison, the steel EUROFER97 were prepared for a post-irradiation tensile test program. During neutron irradiation in the HFR (High Flux Reactor, The Netherlands), an accumulated dose of up to 16.3 dpa was reached for 771 days at full power, with the irradiation temperature ranging between 250 and 450 °C. During the post-examinations, all specimens showed the highest tensile strength at lower irradiation temperatures between 250 and 350 °C. However, ODS-alloy and steel were found to clearly differ in the mechanical behavior, which could be documented by fully instrumented tensile tests. In the un-irradiated state, tensile strength of the ODS-alloy already was increased considerably by about 60% compared to the steel. Strengthening was further increased by another 20% after neutron irradiation, but with a much better ductility than observed in the steel. The typical irradiation-induced strain localization of EUROFER97 or RAFM steels could not be observed in the EUROFER97 ODS HIP alloy.

The relevance of serum levels of long chain omega-3 polyunsaturated fatty acids and prostate cancer risk: A meta-analysis

Science.gov (United States)

Chua, Michael E.; Sio, Maria Christina D.; Sorongon, Mishell C.; Morales, Marcelino L.

2013-01-01

Objective: Our objective was to systematically analyze the evidence for an association between serum level long chain omega-3 polyunsaturated fatty acid (n-3 PUFA) and prostate cancer risk from human epidemiological studies. Study Procedures: We searched biomedical literature databases up to November 2011 and included epidemiological studies with description of long chain n-3 PUFA and incidence of prostate cancer in humans. Critical appraisal was done by two independent reviewers. Data were pooled using the general variance-based method with random-effects model; effect estimates were expressed as risk ratio with 95% confidence interval (CI). Heterogeneity was assessed by Chi2 and quantified by I2, publication bias was also determined. Results: In total, 12 studies were included. Significant negative association was noted between high serum level of n-3 PUFA doc-osapentaenoic acid (DPA) and total prostate cancer risk (RR:0.756; 95% CI 0.599, 0.955; p = 0.019). Likewise, a positive association between high blood level of fish oil contents, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), and high-grade prostate tumour incidence (RR:1.381; 95% CI 1.050, 1.817; p = 0.021) was noted; however, this finding was evident only after adjustment was done on interstudy variability through the removal of a lower quality study from the pool. Conclusions: High serum levels of long chain n-3 PUFA DPA is associated with reduced total prostate cancer risk. While high blood level of EPA and DHA is possibly associated with increased high-grade prostate tumour risk. PMID:23766835

Swelling of Fe-Mn and Fe-Cr-Mn alloys at high neutron fluence

International Nuclear Information System (INIS)

Garner, F.A.; Brager, H.R.

1986-06-01

Swelling data on neutron-irradiated simple Fe-Cr-Mn and Fe-Mn alloys, as well as commercial Fe-Cr-Mn base alloys are now becoming available at exposure levels approaching 50 dpa. The swelling rate decreases from the ∼1%/dpa found at lower exposures, probably due to the extensive formation of ferritic phases. As expected, commercial alloys swell less than the simple alloys

Fractographic examination of reduced activation ferritic/martensitic steel charpy specimens irradiated to 30 dpa at 370{degrees}C

Energy Technology Data Exchange (ETDEWEB)

Gelles, D.S.; Hamilton, M.L. [Pacific Northwest National Lab., Richland, WA (United States); Schubert, L.E. [Univ. of Missouri, Rolla, MO (United States)

1996-10-01

Fractographic examinations are reported for a series of reduced activation ferritic/Martensitic steel Charpy impact specimens tested following irradiation to 30 dpa at 370{degrees}C in FFTF. One-third size specimens of six low activation steels developed for potential application as structural materials in fusion reactors were examined. A shift in brittle fracture appearance from cleavage to grain boundary failure was noted with increasing manganese content. The results are interpreted in light of transmutation induced composition changes in a fusion environment.

Optimization of the testing volumes with respect to neutron flux levels in the two-target high flux D-Li neutron source for the international fusion materials irradiation facility

International Nuclear Information System (INIS)

Kelleher, W.P.; Varsamis, G.L.

1989-01-01

An economic and fusion-relevant source of high-energy neutrons is an essential element in the fusion nuclear technology and development program. This source can be generated by directing a high energy deuteron beam onto a flowing liquid lithium target, producing neutrons via the D-Lithium stripping reaction. Previous work on this type of source concentrated on a design employing one deuteron beam of modest amperage. This design was shown to have a relatively small testing volume with high flux gradients and was therefor considered somewhat unattractive from a materials testing standpoint. A design using two lithium targets and two high-amperage beams has recently been proposed. This two beam design has been examined in an effort to maximize the test volume while minimizing the flux gradients and minimizing the effect of radiation damage on one target due to the other. A spatial, energy and angle dependent neutron source modeling the D-Lithium source was developed. Using this source, a 3-dimensional map of uncollided flux within the test volume was calculated. The results showed that the target separation has little effect on the available experimental volume and that a testing volume of ∼35 liters is available with a volume averaged flux above 10 14 n/cm 2 /s. The collided flux within the test volume was then determined by coupling the source model with a Monte Carlo code. The spectral effects of the high-energy tail in the flux were examined and evaluated as to possible effects on materials response. Calculations comparing the radiation damage to materials from the D-Lithium source to that cause by a standard DT fusion first-wall neutron flux spectrum showed that the number of appm and dpa, as well as the ratio appm/dpa and dpa/MW/m 2 are within 30% for the two sources. 8 refs., 8 figs

Continuous gradient temperature Raman spectroscopy of the long chain polyunsaturated fatty acids docosapentaenoic (DPA, 22:5n-6) and docosahexaenoic (DHA; 22:6n-3) from -100 to 20° C

Science.gov (United States)

Broadhurst, C. Leigh; Schmidt, Walter F.; Kim, Moon S.; Nguyen, Julie K.; Qin, Jianwei; Chao, Kuanglin; Bauchan, Gary L.; Shelton, Daniel R.

2016-05-01

The structural, cognitive and visual development of the human brain and retina strictly require long-chain polyunsaturated fatty acids (LC-PUFA). Excluding water, the mammalian brain is about 60% lipid. One of the great unanswered questions with respect to biological science in general is the absolute necessity of the LC-PUFA docosahexaenoic acid (DHA; 22:6n-3) in these fast signal processing tissues. A lipid of the same chain length with just one less diene group, docosapentaenoic acid (DPA; 22:5n-6) is fairly abundant in terrestrial food chains yet cannot substitute for DHA. Gradient Temperature Raman spectroscopy (GTRS) applies the temperature gradients utilized in differential scanning calorimetry to Raman spectroscopy, providing a straightforward technique to identify molecular rearrangements that occur near and at phase transitions. Herein we apply GTRS to DPA, and DHA from -100 to 20°C. 20 Mb three-dimensional data arrays with 1°C increments and first/second derivatives allows complete assignment of solid, liquid and transition state vibrational modes, including low intensity/frequency vibrations that cannot be readily analyzed with conventional Raman. DPA and DHA show significant spectral changes with premelting (-33 and -60°C, respectively) and melting (-27 and -44°C, respectively). The CH2-(HC=CH)-CH2 moieties are not identical in the second half of the DHA and DPA structures. The DHA molecule contains major CH2 twisting (1265 cm-1) with no noticeable CH2 bending, consistent with a flat helical structure with small pitch. Further modeling of neuronal membrane phospholipids must take into account this structure for DHA, which would be configured parallel to the hydrophilic head group line.

Characterization of neutron-irradiated HT-UPS steel by high-energy X-ray diffraction microscopy

Energy Technology Data Exchange (ETDEWEB)

Zhang, Xuan, E-mail: xuanzhang@anl.gov [Nuclear Engineering Division, Argonne National Laboratory, Lemont, IL 60439 (United States); Park, Jun-Sang; Almer, Jonathan [Advanced Photon Source, Argonne National Laboratory, Lemont, IL 60439 (United States); Li, Meimei [Nuclear Engineering Division, Argonne National Laboratory, Lemont, IL 60439 (United States)

2016-04-01

This paper presents the first measurement of neutron-irradiated microstructure using far-field high-energy X-ray diffraction microscopy (FF-HEDM) in a high-temperature ultrafine-precipitate-strengthened (HT-UPS) austenitic stainless steel. Grain center of mass, grain size distribution, crystallographic orientation (texture), diffraction spot broadening and lattice constant distributions of individual grains were obtained for samples in three different conditions: non-irradiated, neutron-irradiated (3dpa/500 °C), and irradiated + annealed (3dpa/500 °C + 600 °C/1 h). It was found that irradiation caused significant increase in grain-level diffraction spot broadening, modified the texture, reduced the grain-averaged lattice constant, but had nearly no effect on the average grain size and grain size distribution, as well as the grain size-dependent lattice constant variations. Post-irradiation annealing largely reversed the irradiation effects on texture and average lattice constant, but inadequately restored the microstrain.

Synthesis of [125I]iodoDPA-713: A new probe for imaging inflammation

International Nuclear Information System (INIS)

Wang, Haofan; Pullambhatla, Mrudula; Guilarte, Tomas R.; Mease, Ronnie C.; Pomper, Martin G.

2009-01-01

[ 125 I]IodoDPA-713 [ 125 I]1, which targets the translocator protein (TSPO, 18 kDa), was synthesized in seven steps from methyl-4-methoxybenzoate as a tool for quantification of inflammation in preclinical models. Preliminary in vitro autoradiography and in vivo small animal imaging were performed using [ 125 I]1 in a neurotoxicant-treated rat and in a murine model of lung inflammation, respectively. The radiochemical yield of [ 125 I]1 was 44 ± 6% with a specific radioactivity of 51.8 GBq/μmol (1400 mCi/μmol) and >99% radiochemical purity. Preliminary studies showed that [ 125 I]1 demonstrated increased specific binding to TSPO in a neurotoxicant-treated rat and increased radiopharmaceutical uptake in the lungs of an experimental inflammation model of lung inflammation. Compound [ 125 I]1 is a new, convenient probe for preclinical studies of TSPO activity.

Microstructural characterization and density change of 304 stainless steel reflector blocks after long-term irradiation in EBR-II

Energy Technology Data Exchange (ETDEWEB)

Huang, Y., E-mail: yina.huang@materials.ox.ac.uk [University of Wisconsin, Madison, WI 53706 (United States); Wiezorek, J.M.K. [University of Pittsburgh, Pittsburgh, PA 15260 (United States); Garner, F.A. [Radiation Effects Consulting, 2003 Howell Ave., Richland, WA 99354 (United States); Freyer, P.D. [Westinghouse Electric Company LLC, Pittsburgh, PA 15235 (United States); Okita, T. [University of Tokyo, Tokyo (Japan); Sagisaka, M.; Isobe, Y. [Nuclear Fuel Industries, Ltd., Osaka (Japan); Allen, T.R. [University of Wisconsin, Madison, WI 53706 (United States)

2015-10-15

While thin reactor structural components such as cladding and ducts do not experience significant gradients in dpa rate, gamma heating rate, temperature or stress, thick components can develop strong local variations in void swelling and irradiation creep in response to gradients in these variables. In this study we conducted microstructural investigations by transmission electron microscopy of two 52 mm thick 304-type stainless steel hex-blocks irradiated for 12 years in the EBR-II reactor with accumulated doses ranging from ∼0.4 to 33 dpa. Spatial variations in the populations of voids, precipitates, Frank loops and dislocation lines have been determined for 304 stainless steel sections exposed to different temperatures, different dpa levels and at different dpa rates, demonstrating the existence of spatial gradients in the resulting void swelling. The microstructural measurements compare very well with complementary density change measurements regarding void swelling gradients in the 304 stainless steel hex-block components. The TEM studies revealed that the original cold-worked-state microstructure of the unirradiated blocks was completely erased by irradiation, replaced by high densities of interstitial Frank loops, voids and carbide precipitates at both the lowest and highest doses. At large dose levels the amount of volumetric void swelling correlated directly with the gamma heating gradient-related temperature increase (e.g. for 28 dpa, ∼2% swelling at 418 °C and ∼2.9% swelling at 448 °C). Under approximately iso-thermal local conditions, volumetric void swelling was found to increase with dose level (e.g. ∼0.2% swelling at 0.4 dpa, ∼0.5% swelling at 4 dpa and ∼2% swelling at 28 dpa). Carbide precipitate formation levels were found to be relatively independent of both dpa level and temperature and induced a measurable densification. Void swelling was dominant at the higher dose levels and caused measurable decreases in density. Void

Microstructural characterization and density change of 304 stainless steel reflector blocks after long-term irradiation in EBR-II

Science.gov (United States)

Huang, Y.; Wiezorek, J. M. K.; Garner, F. A.; Freyer, P. D.; Okita, T.; Sagisaka, M.; Isobe, Y.; Allen, T. R.

2015-10-01

While thin reactor structural components such as cladding and ducts do not experience significant gradients in dpa rate, gamma heating rate, temperature or stress, thick components can develop strong local variations in void swelling and irradiation creep in response to gradients in these variables. In this study we conducted microstructural investigations by transmission electron microscopy of two 52 mm thick 304-type stainless steel hex-blocks irradiated for 12 years in the EBR-II reactor with accumulated doses ranging from ∼0.4 to 33 dpa. Spatial variations in the populations of voids, precipitates, Frank loops and dislocation lines have been determined for 304 stainless steel sections exposed to different temperatures, different dpa levels and at different dpa rates, demonstrating the existence of spatial gradients in the resulting void swelling. The microstructural measurements compare very well with complementary density change measurements regarding void swelling gradients in the 304 stainless steel hex-block components. The TEM studies revealed that the original cold-worked-state microstructure of the unirradiated blocks was completely erased by irradiation, replaced by high densities of interstitial Frank loops, voids and carbide precipitates at both the lowest and highest doses. At large dose levels the amount of volumetric void swelling correlated directly with the gamma heating gradient-related temperature increase (e.g. for 28 dpa, ∼2% swelling at 418 °C and ∼2.9% swelling at 448 °C). Under approximately iso-thermal local conditions, volumetric void swelling was found to increase with dose level (e.g. ∼0.2% swelling at 0.4 dpa, ∼0.5% swelling at 4 dpa and ∼2% swelling at 28 dpa). Carbide precipitate formation levels were found to be relatively independent of both dpa level and temperature and induced a measurable densification. Void swelling was dominant at the higher dose levels and caused measurable decreases in density. Void swelling

The RaDIATE High-Energy Proton Materials Irradiation Experiment at the Brookhaven Linac Isotope Producer Facility

Energy Technology Data Exchange (ETDEWEB)

Ammigan, Kavin; et al.

2017-05-01

The RaDIATE collaboration (Radiation Damage In Accelerator Target Environments) was founded in 2012 to bring together the high-energy accelerator target and nuclear materials communities to address the challenging issue of radiation damage effects in beam-intercepting materials. Success of current and future high intensity accelerator target facilities requires a fundamental understanding of these effects including measurement of materials property data. Toward this goal, the RaDIATE collaboration organized and carried out a materials irradiation run at the Brookhaven Linac Isotope Producer facility (BLIP). The experiment utilized a 181 MeV proton beam to irradiate several capsules, each containing many candidate material samples for various accelerator components. Materials included various grades/alloys of beryllium, graphite, silicon, iridium, titanium, TZM, CuCrZr, and aluminum. Attainable peak damage from an 8-week irradiation run ranges from 0.03 DPA (Be) to 7 DPA (Ir). Helium production is expected to range from 5 appm/DPA (Ir) to 3,000 appm/DPA (Be). The motivation, experimental parameters, as well as the post-irradiation examination plans of this experiment are described.

Development of high performance ODS alloys

Energy Technology Data Exchange (ETDEWEB)

Shao, Lin [Texas A & M Univ., College Station, TX (United States); Gao, Fei [Univ. of Michigan, Ann Arbor, MI (United States); Garner, Frank [Texas A & M Univ., College Station, TX (United States)

2018-01-29

This project aims to capitalize on insights developed from recent high-dose self-ion irradiation experiments in order to develop and test the next generation of optimized ODS alloys needed to meet the nuclear community's need for high strength, radiation-tolerant cladding and core components, especially with enhanced resistance to void swelling. Two of these insights are that ferrite grains swell earlier than tempered martensite grains, and oxide dispersions currently produced only in ferrite grains require a high level of uniformity and stability to be successful. An additional insight is that ODS particle stability is dependent on as-yet unidentified compositional combinations of dispersoid and alloy matrix, such as dispersoids are stable in MA957 to doses greater than 200 dpa but dissolve in MA956 at doses less than 200 dpa. These findings focus attention on candidate next-generation alloys which address these concerns. Collaboration with two Japanese groups provides this project with two sets of first-round candidate alloys that have already undergone extensive development and testing for unirradiated properties, but have not yet been evaluated for their irradiation performance. The first set of candidate alloys are dual phase (ferrite + martensite) ODS alloys with oxide particles uniformly distributed in both ferrite and martensite phases. The second set of candidate alloys are ODS alloys containing non-standard dispersoid compositions with controllable oxide particle sizes, phases and interfaces.

A two-step transport pathway allows the mother cell to nurture the developing spore in Bacillus subtilis.

Science.gov (United States)

Ramírez-Guadiana, Fernando H; Meeske, Alexander J; Rodrigues, Christopher D A; Barajas-Ornelas, Rocío Del Carmen; Kruse, Andrew C; Rudner, David Z

2017-09-01

One of the hallmarks of bacterial endospore formation is the accumulation of high concentrations of pyridine-2,6-dicarboxylic acid (dipicolinic acid or DPA) in the developing spore. This small molecule comprises 5-15% of the dry weight of dormant spores and plays a central role in resistance to both wet heat and desiccation. DPA is synthesized in the mother cell at a late stage in sporulation and must be translocated across two membranes (the inner and outer forespore membranes) that separate the mother cell and forespore. The enzymes that synthesize DPA and the proteins required to translocate it across the inner forespore membrane were identified over two decades ago but the factors that transport DPA across the outer forespore membrane have remained mysterious. Here, we report that SpoVV (formerly YlbJ) is the missing DPA transporter. SpoVV is produced in the mother cell during the morphological process of engulfment and specifically localizes in the outer forespore membrane. Sporulating cells lacking SpoVV produce spores with low levels of DPA and cells engineered to express SpoVV and the DPA synthase during vegetative growth accumulate high levels of DPA in the culture medium. SpoVV resembles concentrative nucleoside transporters and mutagenesis of residues predicted to form the substrate-binding pocket supports the idea that SpoVV has a similar structure and could therefore function similarly. These findings provide a simple two-step transport mechanism by which the mother cell nurtures the developing spore. DPA produced in the mother cell is first translocated into the intermembrane space by SpoVV and is then imported into the forespore by the SpoVA complex. This pathway is likely to be broadly conserved as DPA synthase, SpoVV, and SpoVA proteins can be found in virtually all endospore forming bacteria.

Potential for bioremediation of agro-industrial effluents with high loads of pesticides by selected fungi.

Science.gov (United States)

Karas, Panagiotis A; Perruchon, Chiara; Exarhou, Katerina; Ehaliotis, Constantinos; Karpouzas, Dimitrios G

2011-02-01

Wastewaters from the fruit packaging industry contain a high pesticide load and require treatment before their environmental discharge. We provide first evidence for the potential bioremediation of these wastewaters. Three white rot fungi (WRF) (Phanerochaete chrysosporium, Trametes versicolor, Pleurotus ostreatus) and an Aspergillus niger strain were tested in straw extract medium (StEM) and soil extract medium (SEM) for degrading the pesticides thiabendazole (TBZ), imazalil (IMZ), thiophanate methyl (TM), ortho-phenylphenol (OPP), diphenylamine (DPA) and chlorpyrifos (CHL). Peroxidase (LiP, MnP) and laccase (Lac) activity was also determined to investigate their involvement in pesticide degradation. T. versicolor and P. ostreatus were the most efficient degraders and degraded all pesticides (10 mg l⁻¹) except TBZ, with maximum efficiency in StEM. The phenolic pesticides OPP and DPA were rapidly degraded by these two fungi with a concurrent increase in MnP and Lac activity. In contrast, these enzymes were not associated with the degradation of CHL, IMZ and TM implying the involvement of other enzymes. T. versicolor degraded spillage-level pesticide concentrations (50 mg l⁻¹) either fully (DPA, OPP) or partially (TBZ, IMZ). The fungus was also able to rapidly degrade a mixture of TM/DPA (50 mg l⁻¹), whereas it failed to degrade IMZ and TBZ when supplied in a mixture with OPP. Overall, T. versicolor and P. ostreatus showed great potential for the bioremediation of wastewaters from the fruit packaging industry. However, degradation of TBZ should be also achieved before further scaling up.

Isolation of a diphenylamine-degrading bacterium and characterization of its metabolic capacities, bioremediation and bioaugmentation potential.

Science.gov (United States)

Perruchon, Chiara; Batianis, Christos; Zouborlis, Stelios; Papadopoulou, Evangelia S; Ntougias, Spyridon; Vasileiadis, Sotirios; Karpouzas, Dimitrios G

2015-12-01

The antioxidant diphenylamine (DPA) is used in fruit-packaging plants for the control of the physiological disorder apple scald. Its use results in the production of DPA-contaminated wastewater which should be treated before finally discharged. Biological treatment systems using tailored-made microbial inocula with specific catabolic activities comprise an appealing and sustainable solution. This study aimed to isolate DPA-degrading bacteria, identify the metabolic pathway of DPA and evaluate their potential for future implementation in bioremediation and biodepuration applications. A Pseudomonas putida strain named DPA1 able to rapidly degrade and utilize DPA as the sole C and N source was enriched from a DPA-contaminated soil. The isolated strain degraded spillage-level concentrations of DPA in liquid culture (2000 mg L(-1)) and in contaminated soil (1000 mg kg(-1)) and metabolized DPA via the transient formation of aniline and catechol. Further evidence for the bioremediation and biodepuration potential of the P. putida strain DPA1 was provided by its capacity to degrade the post-harvest fungicide ortho-phenylphenol (OPP), concurrently used by the fruit-packaging plants, although at slower rates and DPA in a wide range of pH (4.5-9) and temperatures (15-37 °C). These findings revealed the high potential of the P. putida strain DPA1 for use in future soil bioremediation strategies and/or as start-up inocula in wastewater biodepuration systems.

Tensile stress corrosion cracking of type 304 stainless steel irradiated to very high dose

Energy Technology Data Exchange (ETDEWEB)

Chung, H. M.; Ruther, W. E.; Strain, R. V.; Shack, W. J.

2001-09-01

Certain safety-related core internal structural components of light water reactors, usually fabricated from Type 304 or 316 austenitic stainless steels (SSs), accumulate very high levels of irradiation damage (20--100 displacement per atom or dpa) by the end of life. The data bases and mechanistic understanding of, the degradation of such highly irradiated components, however, are not well established. A key question is the nature of irradiation-assisted intergranular cracking at very high dose, i.e., is it purely mechanical failure or is it stress-commotion cracking? In this work, hot-cell tests and microstructural characterization were performed on Type 304 SS from the hexagonal fuel can of the decommissioned EBR-11 reactor after irradiation to {approximately}50 dpa at {approximately}370 C. Slow-strain-rate tensile tests were conducted at 289 C in air and in water at several levels of electrochemical potential (ECP), and microstructural characteristics were analyzed by scanning and transmission electron microcopies. The material deformed significantly by twinning and exhibited surprisingly high ductility in air, but was susceptible to severe intergranular stress corrosion cracking (IGSCC) at high ECP. Low levels of dissolved O and ECP were effective in suppressing the susceptibility of the heavily irradiated material to IGSCC, indicating that the stress corrosion process associated with irradiation-induced grain-boundary Cr depletion, rather than purely mechanical separation of grain boundaries, plays the dominant role. However, although IGSCC was suppressed, the material was susceptible to dislocation channeling at low ECP, and this susceptibility led to poor work-hardening capability and low ductility.

Charpy impact test results of four low activation ferritic alloys irradiated at 370{degrees}C to 15 DPA

Energy Technology Data Exchange (ETDEWEB)

Schubert, L.E.; Hamilton, M.L.; Gelles, D.S. [Pacific Northwest National Lab., Richland, WA (United States)

1996-10-01

Miniature CVN specimens of four low activation ferritic alloys have been impact tested following irradiation at 370{degrees}C to 15 dpa. Comparison of the results with those of control specimens indicates that degradation in the impact behavior occurs in each of these four alloys. The 9Cr-2W alloy referred to as GA3X and the similar alloy F82H with 7.8Cr-2W appear most promising for further consideration as candidate structural materials in fusion energy system applications. These two alloys exhibit a small DBTT shift to higher temperatures but show increased absorbed energy on the upper shelf.

Microstructural evolution of austenitic stainless steels irradiated to 17 dpa in spectrally tailored experiment of the ORR and HFIR at 400{degrees}C

Energy Technology Data Exchange (ETDEWEB)

Wakai, E.; Hashimoto, N.; Gibson, L.T. [Oak Ridge National Lab., TN (United States)] [and others

1997-08-01

The microstructural evolution of austenitic JPCA aged and solution annealed JPCA, 316R, C, K, and HP steels irradiated at 400{degrees}C in spectrally tailored experiments of the ORR and HFIR has been investigated. The helium generation rates were about 12-16 appm He/dpa on the average up to 17.3 dpa. The number densities and average diameters of dislocation loops in the steels have ranges of 3.3 x 10{sup 21} m{sup -3} and 15.2-26.3 nm, respectively, except for HP steel for which they are 1.1 x 10{sup 23} m{sup -3} and 8.0 nm. Precipitates are formed in all steels except for HP steel, and the number densities and average diameters have ranges of 5.2 x 10{sup 20} - 7.7 x 10{sup 21} m{sup -3} and 3.4- 19.3 nm, respectively. In the 216R, C, and K steels, the precipitates are also formed at grain boundaries, and the mean sizes of these are about 110, 50, and 50 nm, respectively. The number densities of cavities are about 1 x 10{sup 22} m{sup -3} in all the steels. The swelling is low in the steels which form the precipitates.

Evolution of microstructure after irradiation creep in several austenitic steels irradiated up to 120 dpa at 320 °C

Energy Technology Data Exchange (ETDEWEB)

Renault-Laborne, A., E-mail: alexandra.renault@cea.fr [DEN-Service de Recherches Métallurgiques Appliquées, CEA, Université Paris-Saclay, F-91191, Gif-sur-Yvette (France); Garnier, J.; Malaplate, J. [DEN-Service de Recherches Métallurgiques Appliquées, CEA, Université Paris-Saclay, F-91191, Gif-sur-Yvette (France); Gavoille, P. [DEN-Service d' Etudes des Matériaux Irradiés, CEA, Université Paris-Saclay, F-91191, Gif-sur-Yvette (France); Sefta, F. [EDF R& D, MMC, Site des Renardières, F-77818, Morêt-sur-Loing Cedex (France); Tanguy, B. [DEN-Service d' Etudes des Matériaux Irradiés, CEA, Université Paris-Saclay, F-91191, Gif-sur-Yvette (France)

2016-07-15

Irradiation creep was investigated in different austenitic steels. Pressurized tubes with stresses of 127–220 MPa were irradiated in BOR-60 at 320 °C to 120 dpa. Creep behavior was dependent on both chemical composition and metallurgical state of steels. Different steels irradiated with and without stress were examined by TEM. Without stress, the irradiation produced high densities of dislocation lines and Frank loops and, depending on the type of steels, precipitates. Stress induced an increase of the precipitate mean size and density and, for some grades, an increase of the mean loop size and a decrease of their density. An anisotropy of Frank loop density or size induced by stress was not observed systematically. Dislocation line microstructure seems not to be different between the stressed and unstressed specimens. No cavities were detectable in these specimens. By comparing with the data from this work, the main irradiation creep models are discussed.

Void swelling of proton-irradiated stainless steel at large displacement levels

International Nuclear Information System (INIS)

Kumar, A.; Garner, F.A.

1982-01-01

The purpose of this study is to determine whether saturation of void swelling in AISI 316 stainless steel can be made to occur at any level relevant to engineering design and to decide whether saturation is sensitive to irradiation variables such as helium/dpa ratio or simulation artifacts such as injected interstitials

Energy Deposition and DPA in the Superconducting Links for the HILUMI LHC Project at the LHC Interaction Points

CERN Document Server

AUTHOR|(CDS)2092158; Broggi, Francesco; Santini, C; Ballarino, Amalia; Cerutti, Francesco; Esposito, Luigi Salvatore

2015-01-01

In the framework of the upgrade of the LHC machine, the powering of the LHC magnets foresees the removal of the power converters and distribution feedboxes from the tunnel and its location at the surface[1]. The Magnesium Diboride (MgB2) connecting lines in the tunnel will be exposed to the debris from 7+7 TeV p-p interaction. The Superconducting (SC) Links will arrive from the surface to the tunnel near the separation dipole, at about 80 m from the Interaction Point at IP1 and IP5. The Connection Box (where the cables of the SC Links are connected to the NbTi bus bar) will be close to the beam pipe. The debris and its effect on the MgB2 SC links in the connection box (energy deposition and displacement per atom) are presented. The effect of thermal neutrons on the Boron consumption and the contribution of the lithium nucleus and the alpha particle on the DPA are evaluated. The results are normalized to an integrated luminosity of 3000 fb-1, value that represents the LHC High Luminosity lifetime. The dose de...

Docosapentaenoic acid and docosahexaenoic acid are positively associated with insulin sensitivity in rats fed high-fat and high-fructose diets.

Science.gov (United States)

Huang, Jiung-Pang; Cheng, Mei-Ling; Hung, Cheng-Yu; Wang, Chao-Hung; Hsieh, Po-Shiuan; Shiao, Ming-Shi; Chen, Jan-Kan; Li, Dai-Er; Hung, Li-Man

2017-10-01

The aim of the present study was to compare insulin resistance and metabolic changes using a global lipidomic approach. Rats were fed a high-fat diet (HFD) or a high-fructose diet (HFrD) for 12 weeks to induce insulin resistance (IR) syndrome. After 12 weeks feeding, physiological and biochemical parameters were examined. Insulin sensitivity and plasma metabolites were evaluated using a euglycemic-hyperinsulinemic clamp and mass spectrometry, respectively. Pearson's correlation coefficient was used to investigate the strength of correlations. Rats on both diets developed IR syndrome, characterized by hypertension, hyperlipidemia, hyperinsulinemia, impaired fasting glucose, and IR. Compared with HFrD-fed rats, non-esterified fatty acids were lower and body weight and plasma insulin levels were markedly higher in HFD-fed rats. Adiposity and plasma leptin levels were increased in both groups. However, the size of adipocytes was greater in HFD- than HFrD-fed rats. Notably, the lipidomic heat map revealed metabolites exhibiting greater differences in HFD- and HFrD-fed rats compared with controls. Plasma adrenic acid levels were higher in HFD- than HFrD-fed rats. Nevertheless, linoleic and arachidonic acid levels decreased in HFrD-fed rats compared with controls. Plasma concentrations of docosapentaenoic acid (DPA) and docosahexaenoic acid (DHA) were significantly reduced after feeding of both diets, particularly the HFrD. There was a strong positive correlation between these two fatty acids and the insulin sensitivity index. The systemic lipidomic analysis indicated that a reduction in DHA and DPA was strongly correlated with IR in rats under long-term overnutrition. These results provide a potential therapeutic target for IR and metabolic syndrome. © 2016 Ruijin Hospital, Shanghai Jiaotong University School of Medicine and John Wiley & Sons Australia, Ltd.

Tensile and stress corrosion cracking properties of type 304 stainless steel irradiated to a very high dose

International Nuclear Information System (INIS)

Chung, H.M.; Strain, R.V.; Shack, W.J.

2001-01-01

Certain safety-related core internal structural components of light water reactors, usually fabricated from Type 304 or 316 austenitic stainless steels (SSs), accumulate very high levels of irradiation damage (20-100 displacement per atom or dpa) by the end of life. Our databases and mechanistic understanding of the degradation of such highly irradiated components, however, are not well established. A key question is the nature of irradiation-assisted intergranular cracking at very high doses, i.e. is it purely mechanical failure or is it stress-corrosion cracking? In this work, hot-cell tests and microstructural characterization were performed on Type 304 SS from the hexagonal fuel can of the decommissioned EBR-II reactor after irradiation to ∼50 dpa at ∼370 deg. C. Slow-strain-rate tensile tests were conducted at 289 degree sign C in air and in water at several levels of electrochemical potential (ECP), and microstructural characteristics were analyzed by scanning and transmission electron microscopies. The material deformed significantly by twinning and exhibited surprisingly high ductility in air, but was susceptible to severe intergranular stress corrosion cracking (IGSCC) at high ECP. Low levels of dissolved O and ECP were effective in suppressing the susceptibility of the heavily irradiated material to IGSCC, indicating that the stress corrosion process associated with irradiation-induced grain-boundary Cr depletion, rather than purely mechanical separation of grain boundaries, plays the dominant role. However, although IGSCC was suppressed, the material was susceptible to dislocation channeling at a low ECP, and this susceptibility led to a poor work-hardening capability and low ductility

Mechanical properties of Mo and TZM alloy neutron-irradiated at high temperatures

International Nuclear Information System (INIS)

Ueda, Kazukiyo; Satou, Manabu; Hasegawa, Akira; Abe, Katsunori

1997-01-01

This work reports the mechanical properties of irradiated molybdenum (Mo) and its alloy, TZM. Recrystallized and stress-relieved specimens were irradiated at five temperatures between 373 and 800degC in FFTF/MOTA to fluence levels of 6.8 to 34 dpa. Irradiation embrittlement and hardening were evaluated by three-point bend test and Vickers hardness test, respectively. Stress-relieved materials showed the enough ductility even after high fluence irradiation. The role of layered structure of stress-relieved specimen was discussed. (author)

Irradiation Creep and Swelling of Russian Ferritic-Martensitic Steels Irradiated to Very High Exposures in the BN-350 Fast Reactor at 305-335 degrees C

International Nuclear Information System (INIS)

Konobeev, Yury V.; Dvoriashin, Alexander M.; Porollo, S.I.; Shulepin, S.V.; Budylkin, N.I.; Mironova, Elena G.; Garner, Francis A.

2003-01-01

Russian ferritic/martensitic (F/M) steels EP-450, EP-852 and EP-823 were irradiated in the BN-350 fast reactor in the form of gas-pressurized creep tubes. The first steel is used in Russia for hexagonal wrappers in fast reactors. The other steels were developed for compatibility with Pb-Bi coolants and serve to enhance our understanding of the general behavior of this class of steels. In an earlier paper we published data on irradiation creep of EP-450 and EP-823 at temperatures between 390 and 520C, with dpa levels ranging from 20 to 60 dpa. In the current paper new data on the irradiation creep and swelling of EP-450 and EP-852 at temperatures between 305 and 335C and doses ranging from 61 to 89 dpa are presented. Where comparisons are possible, it appears that these steels exhibit behavior that is very consistent with that of Western steels. Swelling is relatively low at high neutron exposure and confined to temperatures <420C, but may be camouflaged somewhat by precipitation-related densification. These irradiation creep studies confirm that the creep compliance of F/M steels is about one-half that of austenitic steels.

Swelling of pure copper and copper alloys after high fluence irradiation in FFTF [Fast Flux Test Facility] at approximately 4500C

International Nuclear Information System (INIS)

Garner, F.A.; Brager, H.R.

1986-03-01

The swelling of pure copper and various copper-base alloys has been determined at 47.2 dpa after irradiation in FFTF-MOTA at ∼450 0 C. Data are also becoming available at 63.3 dpa. The alloys tend to fall into two broad categories, those that swell appreciably, sometimes with an S-shaped behavior, and those that resist swelling to very high neutron exposures. It appears that copper may have an intrinsic swelling rate of ∼1%/dpa that is often not reached due to its tendency toward saturation of swelling. The most swelling-resistant alloys examined to date are CuAl25, MZC and Cu-2.0Be

Ion irradiation effects on high purity bcc Fe and model FeCr alloys

International Nuclear Information System (INIS)

Bhattacharya, Arunodaya

2014-01-01

FeCr binary alloys are a simple representative of the reduced activation ferritic/martensitic (F-M) steels, which are currently the most promising candidates as structural materials for the sodium cooled fast reactors (SFR) and future fusion systems. However, the impact of Cr on the evolution of the irradiated microstructure in these materials is not well understood in these materials. Moreover, particularly for fusion applications, the radiation damage scenario is expected to be complicated further by the presence of large quantities of He produced by the nuclear transmutation (∼ 10 appm He/dpa). Within this context, an elaborate ion irradiation study was performed at 500 C on a wide variety of high purity FeCr alloys (with Cr content ranging from ∼ 3 wt.% to 14 wt.%) and a bcc Fe, to probe in detail the influence of Cr and He on the evolution of microstructure. The irradiations were performed using Fe self-ions, in single beam mode and in dual beam mode (damage by Fe ions and co-implantation of He), to separate ballistic damage effect from the impact of simultaneous He injection. Three different dose ranges were studied: high dose (157 dpa, 17 appm He/dpa for the dual beam case), intermediate dose (45 dpa, 57 appm He/dpa for dual beam case) and in-situ low dose (0.33 dpa, 3030 appm He/dpa for the dual beam case). The experiments were performed at the JANNuS triple beam facility and dual beam in situ irradiation facility at CEA-Saclay and CSNSM, Orsay respectively. The microstructure was principally characterized by conventional TEM, APT and EDS in STEM mode. The main results are as follows: 1) A comparison of the cavity microstructure in high dose irradiated Fe revealed strong swelling reduction by the addition of He. It was achieved by a drastic reduction in cavity sizes and an increased number density. This behaviour was observed all along the damage depth, up to the damage peak. 2) Cavity microstructure was also studied in the dual beam high dose

Mechanical behavior of AISI 304SS determined by miniature test methods after neutron irradiation to 28 dpa

Energy Technology Data Exchange (ETDEWEB)

Rabenberg, Ellen M.; Jaques, Brian J. [Department of Materials Science and Engineering, Boise State University, 1910 University Dr., Boise, ID 83725 (United States); Center for Advanced Energy Studies, 995 University Blvd., Idaho Falls, ID 83401 (United States); Sencer, Bulent H. [Center for Advanced Energy Studies, 995 University Blvd., Idaho Falls, ID 83401 (United States); Idaho National Laboratory, Idaho Falls, ID 83415 (United States); Garner, Frank A. [Radiation Effects Consulting, 2003 Howell Ave., Richland, WA 99354 (United States); Freyer, Paula D. [Westinghouse Electric Company LLC, Pittsburgh, PA 15235 (United States); Okita, Taira [Research Into Artifacts Dept., Center for Engineering, University of Tokyo, Tokyo (Japan); Butt, Darryl P., E-mail: DarrylButt@BoiseState.edu [Department of Materials Science and Engineering, Boise State University, 1910 University Dr., Boise, ID 83725 (United States); Center for Advanced Energy Studies, 995 University Blvd., Idaho Falls, ID 83401 (United States)

2014-05-01

The mechanical properties of AISI 304 stainless steel irradiated for over a decade in the Experimental Breeder Reactor (EBR-II) were measured using miniature mechanical testing methods. The shear punch method was used to evaluate the shear strengths of the neutron-irradiated steel and a correlation factor was empirically determined to predict its tensile strength. The strength of the stainless steel slightly decreased with increasing irradiation temperature, and significantly increased with increasing dose until it saturated above approximately 5 dpa. An effective tensile strain hardening exponent was also obtained from the data which shows a relative decrease in ductility of steel with increased irradiation damage. Ferromagnetic measurements were used to observe and deduce the effects of the stress-induced austenite to martensite transformation as a result of shear punch testing.

Synthesis, Characterization, and Initial Biological Evaluation of [99m Tc]Tc-Tricarbonyl-labeled DPA-α-MSH Peptide Derivatives for Potential Melanoma Imaging.

Science.gov (United States)

Gao, Feng; Sihver, Wiebke; Bergmann, Ralf; Belter, Birgit; Bolzati, Cristina; Salvarese, Nicola; Steinbach, Jörg; Pietzsch, Jens; Pietzsch, Hans-Jürgen

2018-06-06

α-Melanocyte stimulating hormone (α-MSH) derivatives target the melanocortin-1 receptor (MC1R) specifically and selectively. In this study, the α-MSH-derived peptide NAP-NS1 (Nle-Asp-His-d-Phe-Arg-Trp-Gly-NH 2 ) with and without linkers was conjugated with 5-(bis(pyridin-2-ylmethyl)amino)pentanoic acid (DPA-COOH) and labeled with [ 99m Tc]Tc-tricarbonyl by two methods. With the one-pot method the labeling was faster than with the two-pot method, while obtaining similarly high yields. Negligible trans-chelation and high stability in physiological solutions was determined for the [ 99m Tc]Tc-tricarbonyl-peptide conjugates. Coupling an ethylene glycol (EG)-based linker increased the hydrophilicity. The peptide derivatives displayed high binding affinity in murine B16F10 melanoma cells as well as in human MeWo and TXM13 melanoma cell homogenates. Preliminary in vivo studies with one of the [ 99m Tc]Tc-tricarbonyl-peptide conjugates showed good stability in blood and both renal and hepatobiliary excretion. Biodistribution was performed on healthy rats to gain initial insight into the potential relevance of the 99m Tc-labeled peptides for in vivo imaging. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Elastic and inelastic light scattering from single bacterial spores in an optical trap allows the monitoring of spore germination dynamics

Science.gov (United States)

Peng, Lixin; Chen, De; Setlow, Peter; Li, Yong-qing

2009-01-01

Raman scattering spectroscopy and elastic light scattering intensity (ESLI) were used to simultaneously measure levels of Ca-dipicolinic acid (CaDPA) and changes in spore morphology and refractive index during germination of individual B. subtilis spores with and without the two redundant enzymes (CLEs), CwlJ and SleB, that degrade spores’ peptidoglycan cortex. Conclusions from these measurements include: 1) CaDPA release from individual wild-type germinating spores was biphasic; in a first heterogeneous slow phase, Tlag, CaDPA levels decreased ∼15% and in the second phase ending at Trelease, remaining CaDPA was released rapidly; 2) in L-alanine germination of wild-type spores and spores lacking SleB: a) the ESLI rose ∼2-fold shortly before Tlag at T1; b) following Tlag, the ESLI again rose ∼2-fold at T2 when CaDPA levels had decreased ∼50%; and c) the ESLI reached its maximum value at ∼Trelease and then decreased; 3) in CaDPA germination of wild-type spores: a) Tlag increased and the first increase in ESLI occurred well before Tlag, consistent with different pathways for CaDPA and L-alanine germination; b) at Trelease the ESLI again reached its maximum value; 4) in L-alanine germination of spores lacking both CLEs and unable to degrade their cortex, the time ΔTrelease (Trelease–Tlag) for excretion of ≥75% of CaDPA was ∼15-fold higher than that for wild-type or sleB spores; and 5) spores lacking only CwlJ exhibited a similar, but not identical ESLI pattern during L-alanine germination to that seen with cwlJ sleB spores, and the high value for ΔTrelease. PMID:19374431

Recent results on the neutron irradiation of ITER candidate copper alloys irradiated in DR-3 at 250{degrees}C to 0.3 dpa

Energy Technology Data Exchange (ETDEWEB)

Edwards, D.J. [Pacific Northwest National Lab., Richland, WA (United States); Singh, B.N.; Toft, P.; Eldrup, M.

1997-04-01

Tensile specimens of CuCrZr and CuNiBe alloys were given various heat treatments corresponding to solution anneal, prime-ageing and bonding thermal treatment with additional specimens re-aged and given a reactor bakeout treatment at 350{degrees}C for 100 h. CuAl-25 was also heat treated to simulate the effects of a bonding thermal cycle on the material. A number of heat treated specimens were neutron irradiated at 250{degrees}C to a dose level of {approximately}0.3 dpa in the DR-3 reactor as Riso. The main effect of the bonding thermal cycle heat treatment was a slight decrease in strength of CuCrZr and CuNiBe alloys. The strength of CuAl-25, on the other hand, remained almost unaltered. The post irradiation tests at 250{degrees}C showed a severe loss of ductility in the case of the CuNiBe alloy. The irradiated CuAl-25 and CuCrZr specimens exhibited a reasonable amount of uniform elongation, with CuCrZr possessing a lower strength.

Tensile properties of a titanium modified austenitic stainless steel and the weld joints after neutron irradiation

Energy Technology Data Exchange (ETDEWEB)

Shiba, K.; Ioka, I.; Jitsukawa, S.; Hamada, A.; Hishinuma, A. [and others

1996-10-01

Tensile specimens of a titanium modified austenitic stainless steel and its weldments fabricated with Tungsten Inert Gas (TIG) and Electron Beam (EB) welding techniques were irradiated to a peak dose of 19 dpa and a peak helium level of 250 appm in the temperature range between 200 and 400{degrees}C in spectrally tailored capsules in the Oak Ridge Research Reactor (ORR) and the High Flux Isotope Reactor (HFIR). The He/dpa ratio of about 13 appm/dpa is similar to the typical helium/dpa ratio of a fusion reactor environment. The tensile tests were carried out at the irradiation temperature in vacuum. The irradiation caused an increase in yield stress to levels between 670 and 800 MPa depending on the irradiation temperature. Total elongation was reduced to less than 10%, however the specimens failed in a ductile manner. The results were compared with those of the specimens irradiated using irradiation capsules producing larger amount of He. Although the He/dpa ratio affected the microstructural change, the impact on the post irradiation tensile behavior was rather small for not only base metal specimens but also for the weld joint and the weld metal specimens.

Mechanical properties and TEM examination of RAFM steels irradiated up to 70 dpa in BOR-60

Energy Technology Data Exchange (ETDEWEB)

Gaganidze, E., E-mail: Ermile.Gaganidze@kit.edu [Karlsruher Institut fuer Technologie, Institut fuer Angewandte Materialien, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Petersen, C.; Materna-Morris, E.; Dethloff, C.; Weiss, O.J.; Aktaa, J. [Karlsruher Institut fuer Technologie, Institut fuer Angewandte Materialien, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Povstyanko, A.; Fedoseev, A.; Makarov, O.; Prokhorov, V. [Joint Stock Company ' State Scientific Centre Research Institute of Atomic Reactors' , 433510 Dimitrovgrad-10, Ulyanovsk Region (Russian Federation)

2011-10-01

Mechanical properties of Reduced Activation Ferritic/Martensitic (RAFM) steels were studied after irradiation in BOR-60 reactor to a neutron displacement damage of 70 dpa at 330-340 deg. C. Yield stress and Ductile-to-Brittle-Transition-Temperature of EUROFER97 indicate saturation of hardening and embrittlement. The phenomenological models for description of microstructure evolution and resulting irradiation hardening and embrittlement are discussed. The evolution of yield stress with dose is qualitatively understood within a Whapham and Makin model. Dislocation loops examined in TEM are considered a main source for low-temperature irradiation hardening. The analysis of the fatigue data in terms of the inelastic strain reveals comparable fatigue behaviour both for unirradiated and irradiated conditions, which can be described by a common Manson-Coffin relation. The study of helium effects in B-doped model steels indicated progressive material embrittlement with helium content. Post-irradiation annealing of RAFM steels yielded substantial recovery of mechanical properties.

DFT studies of the effectiveness of p-substituted diphenyl amine antioxidants in styrene-butadiene rubber through their Cu(II) coordination ability

Science.gov (United States)

Puškárová, Ingrid; Breza, Martin

2017-07-01

Structures of a series of diphenyl amine (DPA) antioxidants and of their complexes with Cu2+ were optimized at B3LYP level of theory. DPAs may be divided into two groups according to their molar antioxidant effectiveness (AEM). The effectiveness of high-AEM DPA antioxidants at 130 °C rises with decreasing spin densities at Cu atoms and with the increasing electron density Laplacian at Cu-N bond critical points in the 2[DPA…Cu]2+ complexes similarly as in the case of p-phenylene diamine antioxidants. No such trends are observed at 25 °C and for low- AEM DPA antioxidants.

Health-Related Quality of Life in University Dance Students.

Science.gov (United States)

White, Hayley M; Hoch, Johanna M; Hoch, Matthew C

2018-03-01

Injuries are common among dancers and may negatively affect health-related quality of life (HRQL). The modified Disablement in the Physically Active Scale (mDPA) is a generic patient-reported outcome instrument that could be used when providing care to patients participating in performing arts. The objective of this pilot study was to examine the internal consistency of the mDPA and assess overall HRQL using the mDPA in university dance students. Thirty-one female university dance students completed the mDPA during one data collection session. Higher scores on the Physical Summary Component (mDPA-PSC), the Mental Summary Component (mDPAMSC), and mDPA-Total indicated increased disablement. The internal consistency was determined using Cronbachs alpha. The mDPA-Total, mDPA-PSC, and mDPAMSC scores were examined descriptively using mean and standard deviations. Individual item responses were also examined. The proportion of university dance students with clinically relevant levels of disablement on the mDPA-Total was examined using a previously established minimally clinically important difference value. The internal consistency for the mDPA-MSC (a=0.91) and mDPATotal (a=0.90) was excellent and good for the mDPA-PSC (a=0.88). A large proportion (71%) of university dance students demonstrated clinically relevant levels of disablement despite fully participating in dance-related activities. Pain, impaired motion, and stress were the greatest contributors to increased disablement in these individuals. The mDPA scores observed in this pilot study indicate that many dance students experience levels of disablement and decreased HRQL which may warrant physical and mental intervention. Clinicians providing healthcare services to performing artists should consider using the mDPA to provide patient-centered care.

A comparison of the iraddiated tensile properties of a high-manganese austenitic steel and type 316 stainless steel

International Nuclear Information System (INIS)

Klueh, R.L.; Grossbeck, M.L.

1984-01-01

The USSR steel EP-838 is a high-manganese, low-nickel steel that also has lower chromium and molybdenum than type 316 stainless steel. Tensile specimens of 20%-cold-worked EP-838 and type 316 stainless steel were irradiated in the High Flux Isotope Reactor (HFIR) at the coolant temperature (approx.=50 0 C). A displacement damage level of 5.2 dpa was reached for the EP-838 and up to 9.5 dpa for the type 316 stainless steel. Tensile tests at room temperature and 300 0 C on the two steels indicated that the irradiation led to increased strength and decreased ductility compared to the unirradiated steels. Although the 0.2% yield stress of the type 316 stainless steel in the unirradiated condition was greater than that for the EP-838, after irradiation there was essentially no difference between the strength or ductility of the two steels. The results indicate that the replacement of the majority of the nickel by manganese and a reduction of chromium and molybdenum in an austenitic stainless steel of composition near that for type 316 stainless steel has little effect on the irradiated and unirradiated tensile properties at low temperatures. (orig.)

Self-ion emulation of high dose neutron irradiated microstructure in stainless steels

Science.gov (United States)

Jiao, Z.; Michalicka, J.; Was, G. S.

2018-04-01

Solution-annealed 304L stainless steel (SS) was irradiated to 130 dpa at 380 °C, and to 15 dpa at 500 °C and 600 °C, and cold-worked 316 SS (CW 316 SS) was irradiated to 130 dpa at 380 °C using 5 MeV Fe++/Ni++ to produce microstructures and radiation-induced segregation (RIS) for comparison with that from neutron irradiation at 320 °C to 46 dpa in the BOR60 reactor. For the 304L SS alloy, self-ion irradiation at 380 °C produced a dislocation loop microstructure that was comparable to that by neutron irradiation. No voids were observed in either the 380 °C self-ion irradiation or the neutron irradiation conditions. Irradiation at 600 °C produced the best match to radiation-induced segregation of Cr and Ni with the neutron irradiation, consistent with the prediction of a large temperature shift by Mansur's invariant relations for RIS. For the CW 316 SS alloy irradiated to 130 dpa at 380 °C, both the irradiated microstructure (dislocation loops, precipitates and voids) and RIS reasonably matched the neutron-irradiated sample. The smaller temperature shift for RIS in CW 316 SS was likely due to the high sink (dislocation) density induced by the cold work. A single self-ion irradiation condition at a dose rate ∼1000× that in reactor does not match both dislocation loops and RIS in solution-annealed 304L SS. However, a single irradiation temperature produced a reasonable match with both the dislocation/precipitate microstructure and RIS in CW 316 SS, indicating that sink density is a critical factor in determining the temperature shift for self-ion irradiations.

Irradiation creep and void swelling of two LMR heats of HT9 at ∝400 C and 165 dpa

International Nuclear Information System (INIS)

Toloczko, M.B.; Garner, F.A.

1996-01-01

Two nominally identical heats of HT9 ferritic-martensitic steel were produced, fabricated into pressurized tubes, and then irradiated in FFTF, using identical procedures. After reaching 165 dpa at ∝400 C, small differences in strains associated with both phase-related changes in lattice parameter and void swelling were observed in comparing the two heats. The creep strains, while different, exhibited the same functional dependence on swelling behavior. The derived creep coefficients, the one associated with creep in the absence of swelling and the one directly responsive to swelling, were essentially identical for the two heats. Even more significantly, the creep coefficients for this bcc ferritic-martensitic steel appear to be very similar and possibly identical to those routinely derived from creep experiments on fcc austenitic steels. (orig.)

Daily Physical Activity Survey Report

Science.gov (United States)

Alberta Education, 2008

2008-01-01

The intent of the Daily Physical Activity (DPA) Survey was to gather school-level information from teachers and principals regarding their perceptions of DPA, thus providing a greater understanding of DPA implementation in grades 1 to 9. This study aimed to help identify the many variables that influence the attainment of the DPA outcomes and…

High-level verification

CERN Document Server

Lerner, Sorin; Kundu, Sudipta

2011-01-01

Given the growing size and heterogeneity of Systems on Chip (SOC), the design process from initial specification to chip fabrication has become increasingly complex. This growing complexity provides incentive for designers to use high-level languages such as C, SystemC, and SystemVerilog for system-level design. While a major goal of these high-level languages is to enable verification at a higher level of abstraction, allowing early exploration of system-level designs, the focus so far for validation purposes has been on traditional testing techniques such as random testing and scenario-based

Development of radiation-hardened ceramic composites for fusion applications. Technical progress report, September 1, 1993--August 31, 1994

Energy Technology Data Exchange (ETDEWEB)

Osborne, M.C.; Steiner, D. [Rensselaer Polytechnic Institute, Troy, NY (United States); Snead, L.L. [Oak Ridge National Lab., TN (United States)

1994-05-01

The strength and toughness of continuous fiber reinforced ceramic composites (CFCC) are highly dependent on the fiber strength distribution. To first order, weaker fibers lead to low strength but higher toughness while stronger fibers lead to high strength composites of relatively low toughness. Toughness is associated with pullout of the fibers from the ceramic matrix. It has been shown previously that both strength and toughness of SiC/Nicalon{sup TM} composites are drastically changed following irradiation. This paper will present and discuss results for low oxygen Nicalon fibers irradiated at three damage levels; 0.013 dpa, 0.13 dpa, and 0.32 dpa. Single fibers were tensile tested and analyzed, using Weibull statistics, for mean strength and distribution. Tensile modulus was also determined. Using a diffractometer, the fiber grain size and percent crystallinity were determined. The initial results of these low level neutron irradiations exhibit no substantial degradation of the properties investigated. Therefore, continued research at higher doses is recommended.

Development of radiation-hardened ceramic composites for fusion applications. Technical progress report, September 1, 1993--August 31, 1994

International Nuclear Information System (INIS)

Osborne, M.C.; Steiner, D.; Snead, L.L.

1994-05-01

The strength and toughness of continuous fiber reinforced ceramic composites (CFCC) are highly dependent on the fiber strength distribution. To first order, weaker fibers lead to low strength but higher toughness while stronger fibers lead to high strength composites of relatively low toughness. Toughness is associated with pullout of the fibers from the ceramic matrix. It has been shown previously that both strength and toughness of SiC/Nicalon TM composites are drastically changed following irradiation. This paper will present and discuss results for low oxygen Nicalon fibers irradiated at three damage levels; 0.013 dpa, 0.13 dpa, and 0.32 dpa. Single fibers were tensile tested and analyzed, using Weibull statistics, for mean strength and distribution. Tensile modulus was also determined. Using a diffractometer, the fiber grain size and percent crystallinity were determined. The initial results of these low level neutron irradiations exhibit no substantial degradation of the properties investigated. Therefore, continued research at higher doses is recommended

Calculation of DPA in the Reactor Internal Structural Materials of Nuclear Power Plant

International Nuclear Information System (INIS)

Kim, Yong Deong; Lee, Hwan Soo

2014-01-01

The embrittlement is mainly caused by atomic displacement damage due to irradiations with neutrons, especially fast neutrons. The integrity of the reactor internal structural materials has to be ensured over the reactor life time, threatened by the irradiation induced displacement damage. Accurate modeling and prediction of the displacement damage is a first step to evaluate the integrity of the reactor internal structural materials. Traditional approaches for analyzing the displacement damage of the materials have relied on tradition model, developed initially for simple metals, Kinchin and Pease (K-P), and the standard formulation of it by Norgett et al. , often referred to as the 'NRT' model. An alternative and complementary strategy for calculating the displacement damage is to use MCNP code. MCNP uses detailed physics and continuous-energy cross-section data in its simulations. In this paper, we have performed the evaluation of the displacement damage of the reactor internal structural materials in Kori NPP unit 1 using detailed Monte Carlo modeling and compared with predictions results of displacement damage using the classical NRT model. The evaluation of the displacement damage of the reactor internal structural materials in Kori NPP unit 1 using detailed Monte Carlo modeling has been performed. The maximum value of the DPA rate was occurred at the baffle side of the reactor internal where the node has the maximum neutron flux

EU Development of High Heat Flux Components

International Nuclear Information System (INIS)

Linke, J.; Lorenzetto, P.; Majerus, P.; Merola, M.; Pitzer, D.; Roedig, M.

2005-01-01

The development of plasma facing components for next step fusion devices in Europe is strongly focused to ITER. Here a wide spectrum of different design options for the divertor target and the first wall have been investigated with tungsten, CFC, and beryllium armor. Electron beam simulation experiments have been used to determine the performance of high heat flux components under ITER specific thermal loads. Beside thermal fatigue loads with power density levels up to 20 MWm -2 , off-normal events are a serious concern for the lifetime of plasma facing components. These phenomena are expected to occur on a time scale of a few milliseconds (plasma disruptions) or several hundred milliseconds (vertical displacement events) and have been identified as a major source for the production of neutron activated metallic or tritium enriched carbon dust which is of serious importance from a safety point of view.The irradiation induced material degradation is another critical concern for future D-T-burning fusion devices. In ITER the integrated neutron fluence to the first wall and the divertor armour will remain in the order of 1 dpa and 0.7 dpa, respectively. This value is low compared to future commercial fusion reactors; nevertheless, a nonnegligible degradation of the materials has been detected, both for mechanical and thermal properties, in particular for the thermal conductivity of carbon based materials. Beside the degradation of individual material properties, the high heat flux performance of actively cooled plasma facing components has been investigated under ITER specific thermal and neutron loads

A broadband high-efficiency Doherty power amplifier using symmetrical devices

Science.gov (United States)

Cheng, Zhiqun; Zhang, Ming; Li, Jiangzhou; Liu, Guohua

2018-04-01

This paper proposes a method for broadband and high-efficiency amplification of Doherty power amplifier (DPA) using symmetric devices. In order to achieve the perfect load modulation, the carrier amplifier output circuit total power length is designed to odd multiple of 90°, and the peak amplifier output total power length is designed to even multiple of 180°. The proposed method is demonstrated by designing a broadband high-efficiency DPA using identical 10-W packaged GaN HEMT devices. Measurement results show that over 51% drain efficiency is achieved at 6-dB back-off power, over the frequency band of 1.9–2.4 GHz. Project supported by the National Natural Science Foundation of China (No. 60123456), the Zhejiang Provincial Natural Science Foundation of China (No. LZ16F010001), and the Zhejiang Provincial Public Technology Research Project (No. 2016C31070).

Microstructural evolution in low alloy steels under high dose ion irradiation

International Nuclear Information System (INIS)

Fujii, Katsuhiko; Fukuya, Koji; Ohkubo, Tadakatsu; Hono, Kazuhiro

2006-01-01

Radiation hardening and microstructural evolution in low Cu A533B steels (0.03 wt% Cu) irradiated by 3 MeV Ni 2+ ions at 290degC to 1 dpa were investigated by ultra-micro hardness measurement and leaser type three dimensional atom probe analysis. Mn-Ni-Si enriched precipitates were detected in the samples irradiated to 1 dpa by 3DAP analysis. The well-defined precipitates had a size of less than 4 nm, and the number density increased with dose. The formation of the precipitates under high dose rate irradiation suggested that Mn-Ni-Si enriched precipitates were formed by a process such as radiation induced precipitation rather than by thermal equilibrium process. The increase of yield stress calculated by size and number density of the precipitates in 1 dpa irradiated sample using the similar value of hardening efficiency to that of Cu rich precipitates was consistent with that estimated by data of increases of hardness measured by nano-indentation. The result indicates that effects of Mn-Ni-Si enriched precipitates on radiation embrittlement are similar to those of Cu rich precipitates. (author)

Helium influence on the microstructure and swelling of 9%Cr ferritic steel after neutron irradiation to 16.3 dpa

International Nuclear Information System (INIS)

Klimenkov, M.; Möslang, A.; Materna-Morris, E.

2014-01-01

Specially fabricated samples of the European reference 9Cr-WTaV steel EUROFER 97 alloyed with 0.081 mass% natural B and 0.081 and 0.114 mass% pure isotope 10 B were neutron-irradiated with about 16.3 dpa at temperatures in the range from 523 K to 723 K to study the influence of helium produced by 10 B(n,α) 7 Li transmutation reaction on microstructure, swelling and hardness. The spatial and size distributions of helium bubbles or cavities after irradiation at different temperatures were investigated by transmission electron microscopy. Vickers microhardness HV0.1 tests were performed on the as received specimens and specimens after irradiation. The influence of irradiation temperature and helium concentration on the size and density of the bubbles or cavities was analyzed and correlations with the hardness, tensile properties, and the fracture surface were discussed

Irradiation creep and void swelling of two LMR heat of HT9 at ∼400 degrees C and 165 dpa

International Nuclear Information System (INIS)

Toloczko, M.B.; Garner, F.A.

1996-01-01

Two nominally identical heats of HT9 ferritic-martensitic steel were produced, fabricated into pressurized tubes, and then irradiated in FFTF, using identical procedures. After reaching 165 dpa at ∼400C, small differences in strains associated with both phase-related change in lattice parameter and void swelling were observed in comparing the two heats. The creep strains, while different, exhibited the same functional relationship to the swelling behavior. The derived creep coefficients, the one associated with creep in the absence of swelling and the one directly responsive to swelling, were essentially identical for the two heats. Even more significantly, the creep coefficients for this bcc ferritic-martensitic steel appear to be very similar and possibly identical to those routinely derived from creep experiments on fcc austenitic steels

Fatty Acid Composition and Levels of Selected Polyunsaturated Fatty Acids in Four Commercial Important Freshwater Fish Species from Lake Victoria, Tanzania

Directory of Open Access Journals (Sweden)

Agnes Robert

2014-01-01

Full Text Available Fatty acids (FAs particularly ω3 and ω6 polyunsaturated fatty acids (PUFAs play important role in human health. This study aimed to investigate the composition and levels of selected ω3 PUFAs in four commercial fish species, Nile perch (Lates niloticus, Nile tilapia (Oreochromis niloticus, Tilapia zillii, and dagaa (Rastrineobola argentea from Mwanza Gulf in Lake Victoria. The results indicated that 36 types of FAs with different saturation levels were detected. These FAs were dominated by docosahexaenoic (DHA, eicosapentaenoic (EPA, docosapentaenoic (DPA, and eicosatetraenoic acids. O. niloticus had the highest composition of FAs (34 compared to L. niloticus (27, T. zillii (26, and R. argentea (21. The levels of EPA differed significantly among the four commercial fish species (F=6.19,  P=0.001. The highest EPA levels were found in R. argentea followed by L. niloticus and O. niloticus and the lowest in T. zillii. The DPA levels showed no significant difference among the four fish species studied (F=0.652,  P=0.583. The study concluded that all four commercial species collected from Mwanza Gulf are good for human health, but R. argentea is the best for consumption because it contains higher levels of ω3 FAs, mainly EPA.

Highly red-shifted NIR emission from a novel anthracene conjugated polymer backbone containing Pt( ii ) porphyrins

KAUST Repository

Freeman, D. M. E.

2015-11-30

© The Royal Society of Chemistry 2016. We present the synthesis of a novel diphenylanthracene (DPA) based semiconducting polymer. The polymer is solubilised by alkoxy groups attached directly to a DPA monomer, meaning the choice of co-monomer is not limited to exclusively highly solubilising moieties. Interestingly, the polymer shows a red-shifted elecroluminescence maximum (510 nm) when compared to its photoluminescence maximum (450 nm) which we attribute to excimer formation. The novel polymer was utilised as a host for a covalently-linked platinum(ii) complexed porphyrin dopant. Emission from these polymers was observed in the NIR and again showed almost a 100 nm red shift from photoluminescence to electroluminescence. This work demonstrates that utilising highly aggregating host materials is an effective tool for inducing red-shifted emission in OLEDs.

Hardening and microstructural evolution of A533b steels irradiated with Fe ions and electrons

Energy Technology Data Exchange (ETDEWEB)

Watanabe, H., E-mail: watanabe@riam.kyushu-u.ac.jp [Research Institute for Applied Mechanics, Kyushu University, 6-1, Kasuga-kouenn, Kasugashi, Fukuoka, 816-8580 (Japan); Arase, S. [Interdisciplinary Graduate School of Kyushu University, 6-1, Kasuga-kouenn, Kasugashi, Fukuoka, 816-8580 (Japan); Yamamoto, T.; Wells, P. [Dept. Chemical Engineering, UCSB Engineering II, RM3357, Santa Barbara, CA, 93106-5080 (United States); Onishi, T. [Interdisciplinary Graduate School of Kyushu University, 6-1, Kasuga-kouenn, Kasugashi, Fukuoka, 816-8580 (Japan); Odette, G.R. [Dept. Chemical Engineering, UCSB Engineering II, RM3357, Santa Barbara, CA, 93106-5080 (United States)

2016-04-01

Radiation hardening and embrittlement of A533B steels is heavily dependent on the Cu content. In this study, to investigate the effect of copper on the microstructural evolution of these materials, A533B steels with different Cu levels were irradiated with 2.4 MeV Fe ions and 1.0 MeV electrons. Ion irradiation was performed from room temperature (RT) to 350 °C with doses up to 1 dpa. At RT and 290 °C, low dose (<0.1 dpa) hardening trend corresponded with ΔH ∝ (dpa){sup n}, with n initially approximately 0.5 and consistent with a barrier hardening mechanism, but saturating at ≈0.1 dpa. At higher dose levels, the radiation-induced hardening exhibited a strong Cu content dependence at 290 °C, but not at 350 °C. Electron irradiation using high-voltage electron microscopy revealed the growth of interstitial-type dislocation loops and enrichment of Ni, Mn, and Si in the vicinities of pre-existing dislocations at doses for which the radiation-induced hardness due to ion irradiation was prominent.

Dose dependence of the microstructural evolution in neutron-irradiated austenitic stainless steel

International Nuclear Information System (INIS)

Zinkle, S.J.; Maziasz, P.J.; Stoller, R.E.

1993-01-01

Microstructural data on the evolution of the dislocation loop, cavity, and precipitate populations in neutron-irradiated austenitic stainless steels are reviewed in order to estimate the displacement damage levels needed to achieve the 'steady state' condition. The microstructural data can be conveniently divided into two temperature regimes. In the low temperature regime (below about 200 degrees C) the microstructure of austenitic stainless steel is dominated by 'black spot' defect clusters and faulted interstitial dislocation loops. The dose needed to approach saturation of the loop and defect cluster densities is generally on the order of 1 displacement per atom (dpa) in this regime. In the high temperature regime (∼300 to 700 degrees C), cavities, precipitates, loops and network dislocations are all produced during irradiation; doses in excess of 10 dpa are generally required to approach a 'steady state' microstructural condition. Due to complex interactions between the various microstructural components that form during irradiation, a secondary transient regime is typically observed in commercial stainless steels during irradiation at elevated temperatures. This slowly evolving secondary transient may extend to damage levels in excess of 50 dpa in typical 300-series stainless steels, and to >100 dpa in radiation-resistant developmental steels. The detailed evolution of any given microstructural component in the high-temperature regime is sensitive to slight variations in numerous experimental variables, including heat-to-heat composition changes and neutron spectrum

Microstructural stability of a self-ion irradiated lanthana-bearing nanostructured ferritic steel

International Nuclear Information System (INIS)

Pasebani, Somayeh; Charit, Indrajit; Burns, Jatuporn; Price, Lloyd M.; M Univ., College Station, TX; Shao, Lin; M Univ., College Station, TX

2015-01-01

Thermally stable nanofeatures with high number density are expected to impart excellent high temperature strength and irradiation stability in nanostructured ferritic steels (NFSs) which have potential applications in advanced nuclear reactors. A lanthana-bearing NFS (14LMT) developed via mechanical alloying and spark plasma sintering was used in this study. The sintered samples were irradiated by Fe 2+ ions to 10, 50 and 100 dpa at 30 °C and 500 °C. Microstructural and mechanical characteristics of the irradiated samples were studied using different microscopy techniques and nanoindentation, respectively. Overall morphology and number density of the nanofeatures remained unchanged after irradiation. Average radius of nanofeatures in the irradiated sample (100 dpa at 500 °C) was slightly reduced. A notable level of irradiation hardening and enhanced dislocation activity occurred after ion irradiation except at 30 °C and ≥50 dpa. Other microstructural features like grain boundaries and high density of dislocations also provided defect sinks to assist in defect removal.

The comparison of microstructure and nanocluster evolution in proton and neutron irradiated Fe–9%Cr ODS steel to 3 dpa at 500 °C

Energy Technology Data Exchange (ETDEWEB)

Swenson, M.J., E-mail: matthewswenson1@u.boisestate.edu; Wharry, J.P.

2015-12-15

A model Fe–9%Cr oxide dispersion strengthened (ODS) steel was irradiated with protons or neutrons to a dose of 3 displacements per atom (dpa) at a temperature of 500 °C, enabling a direct comparison of ion to neutron irradiation effects at otherwise fixed irradiation conditions. The irradiated microstructures were characterized using transmission electron microscopy and atom probe tomography including cluster analysis. Both proton and neutron irradiations produced a comparable void and dislocation loop microstructure. However, the irradiation response of the Ti–Y–O oxide nanoclusters varied. Oxides remained stable under proton irradiation, but exhibited dissolution and an increase in Y:Ti composition ratio under neutron irradiation. Both proton and neutron irradiation also induced varying extents of Si, Ni, and Mn clustering at existing oxide nanoclusters. Protons are able to reproduce the void and loop microstructure of neutron irradiation carried out to the same dose and temperature. However, since nanocluster evolution is controlled by both diffusion and ballistic impacts, protons are rendered unable to reproduce the nanocluster evolution of neutron irradiation at the same dose and temperature. - Highlights: • Fe–9% Cr ODS was irradiated with protons and neutrons to 3 dpa at 500 °C. • Dislocation loop size and density were similar upon proton and neutron irradiation. • Oxide nanocluster size and density decreased more with neutron irradiation. • Oxide Y:Ti ratio increased from 0.54 to 0.97 upon neutron irradiation. • Irradiation induced enrichment of Si, Mn, and Ni at oxide locations.

Omega-3 fatty acid levels and general performance of commercial broilers fed practical levels of redfish meal.

Science.gov (United States)

Hulan, H W; Ackman, R G; Ratnayake, W M; Proudfoot, F G

1989-01-01

A total of 1,200 day-old Arbor Acre broiler chickens was randomly assigned to 12 pens (50 males and 50 females/pen) and divided into three blocks of four pens each. Each of four different diets was fed ad libitum to one pen of birds within each block to determine the effect of feeding practical levels of redfish meal (RFM) on performance and omega-3 fatty acid content of edible meat and skin lipids of broiler chickens. The four diets included (control) 0%, 4.0%, 8.0%, and 12.0% RFM. Feeding diets containing RFM had no effect on overall mortality or feed efficiency but resulted in decreased incidence of sudden death syndrome and lower body weight (P less than .01) and feed consumption (P less than .05). Additions of RFM to the diets resulted in a substantial dietary enrichment of omega-3 fatty acids (especially eicosapentaenoic acid, EPA or 20:5n-3, and docosahexaenoic acid, DHA or 22:6n-3). Analyses (wt/wt%) revealed that breast meat (less skin) was lower (P less than .001) in lipid and triglyceride but higher in free cholesterol (P less than .001) and phospholipid (P less than .001) than thigh meat (less skin). Dietary treatment had no effect on carcass lipid content or composition. Breast meat lipid contained more (P less than .001) omega-3 fatty acids (especially EPA and DHA), more docosapentaenoic acid, (DPA or 22:5n-3) and more total omega-3 polyunsaturated acids (n-3 PUFA) than thigh meat lipids. Feeding additional RFM resulted in an increased (P less than .001) accumulation of EPA, DPA, DHA, and total n-3 PUFA primarily at the expense of two omega-6 fatty acids, linoleic (18:2n-6) and arachidonic acid (20:4n-6). It can be calculated from the data presented that the consumption of 100 g of chicken that has been fed 12.0% RFM would contribute approximately 197 mg of omega-3 fatty acids (EPA + DPA + DHA) in contrast with the 138 mg of omega-3 fatty acids which would be realized from the consumption of 100 g of white fish such as cod.

Sustained hypoxia leads to the emergence of cells with enhanced growth, migratory, and promitogenic potentials within the distal pulmonary artery wall.

Science.gov (United States)

Frid, Maria G; Li, Min; Gnanasekharan, Meena; Burke, Danielle L; Fragoso, Miguel; Strassheim, Derek; Sylman, Joanna L; Stenmark, Kurt R

2009-12-01

All forms of chronic pulmonary hypertension (PH) are characterized by structural remodeling of the pulmonary artery (PA) media, a process previously attributed solely to changes in the phenotype of resident smooth muscle cells (SMC). However, recent experimental evidence in both systemic and pulmonary circulations suggests that other cell types, including circulating and local progenitors, contribute significantly to this process. The goal of this study was to determine if hypoxia-induced remodeling of distal PA (dPA) media involves the emergence of cells with phenotypic and functional characteristics distinct from those of resident dPA SMC and fibroblasts. In vivo, in contrast to the phenotypically uniform SMC composition of dPA media in control calves, the remodeled dPA media of neonatal calves with severe hypoxia-induced PH comprised cells exhibiting a distinct phenotype, including the expression of hematopoetic (CD45), leukocytic/monocytic (CD11b, CD14), progenitor (cKit), and motility-associated (S100A4) cell markers. Consistent with these in vivo observations, primary cell cultures isolated from dPA media of hypertensive calves yielded not only differentiated SMC, but also smaller, morphologically rhomboidal (thus termed here "R") cells that transiently expressed CD11b, constitutively expressed the mesenchymal cell marker type I procollagen, expressed high mRNA levels of progenitor cell markers cKit, CD34, CD73, as well as for inflammatory mediators, IL-6 and MCP-1, and, with time in culture, gained expression of a myofibroblast marker, alpha-SM-actin. R cells exhibited highly augmented proliferative, migratory, invasive, and potent promitogenic capabilities, which were due, at least in part, to the production of PDGFs, SDF-1/CXCL12, and S100A4. These data suggest that the cellular mechanisms of dPA remodeling include the emergence of cells with phenotypic and functional characteristics markedly distinct from those of resident dPA cells.

Radiation damage simulation studies in the Harwell VEC of selected austenitic and ferritic alloys for fusion applications

Energy Technology Data Exchange (ETDEWEB)

Mazey, D J; Walters, G P; Buckley, S N; Hanks, W; Bolster, D E.J.; Murphy, S M

1988-07-01

Three austenitic (316 L, 316-Ti, 316-Nb); four high-nickel (IN 625, IN 706, PE 16, Fe-25Ni-8Cr) and four ferritic (CRM 12, FV 448, FV 607, FI) alloys have been irradiated with 46 MeV Ni or 20 MeV Cr ions in the Harwell VEC to simulated fusion-reactor doses up to 110 dpa (proportional to 10 MW-yr m/sup -2/) at temperatures from 425 to 625/sup 0/C. Gas production rates appropriate to fusion were obtained from a mixed beam of He+H/sub 2/ in the ratio 1:4 He:H with gas/dpa ratios of 13 appm He/dpa and 52 appm H/dpa. The 316 alloys showed irradiation-induced precipitation and swelling as high as 40% in ST 316-Ti after 110 dpa at 625/sup 0/C. Low swelling (e.g. <2% at 110 dpa) was observed in the high-nickel alloys. The ferritic/martensitic alloys showed negligible swelling (e.g. <0.2% in FV 607 after 100 dpa at 475/sup 0/C). The results demonstrate the high swelling behaviour of 316 alloys and the better swelling resistance of high-nickel and ferritic alloys under simulated fusion conditions.

Optimization of the synthesis of SAPO-11 for the methylation of naphthalene with methanol by varying templates and template content

International Nuclear Information System (INIS)

Wang, Xiaoxiao; Zhang, Wei; Zhao, Liangfu; Xiang, Hongwei; Guo, Shaoqing

2013-01-01

SAPO-11 zeolites were successfully synthesized by using three different templates (diethylamine (DEA), di-n-propylamine (DPA) and di-isopropylamine (DIPA)) and varying DPA contents (nDPA/Al 2 O 3 = 0.8, 1.2, 1.6 and 2.0) under hydrothermal conditions. The samples were characterized by powder X-ray diffractometry (XRD), scanning electron microscopy (SEM), N 2 adsorption-desorption, temperature programmed desorption of ammonia (NH 3 -TPD) and 29 Si magic angle spinning (MAS) nuclear magnetic resonance (NMR). The samples were also evaluated towards the methylation of naphthalene with methanol to produce 2,6-dimethylnaphthalene (2,6-DMN). XRD results indicated that the directing effect of the different templates for AEL (Aluminophosphate-ELeven) structure decreased in the order DPA > DEA > DIPA and the most suitable DPA content was nDPA/Al 2 O 3 = 1.2. N 2 adsorption-desorption results showed that SAPO-11(DPA,1.2) exhibited the broadest pore size distribution, the highest BET specific surface area and the largest pore volume among all the SAPO-11 samples. SAPO-11(DPA,1.2) exhibited high catalytic performances in the methylation of naphthalene due to its high crystallinity, high external surface and broad pore size distribution. The pore structure of SAPO-11 zeolite, rather than its acidity, played an important role in achieving high catalytic performances in the methylation of naphthalene with methanol. (author)

Fast dynamics perturbation analysis for prediction of protein functional sites

Directory of Open Access Journals (Sweden)

Cohn Judith D

2008-01-01

Full Text Available Abstract Background We present a fast version of the dynamics perturbation analysis (DPA algorithm to predict functional sites in protein structures. The original DPA algorithm finds regions in proteins where interactions cause a large change in the protein conformational distribution, as measured using the relative entropy Dx. Such regions are associated with functional sites. Results The Fast DPA algorithm, which accelerates DPA calculations, is motivated by an empirical observation that Dx in a normal-modes model is highly correlated with an entropic term that only depends on the eigenvalues of the normal modes. The eigenvalues are accurately estimated using first-order perturbation theory, resulting in a N-fold reduction in the overall computational requirements of the algorithm, where N is the number of residues in the protein. The performance of the original and Fast DPA algorithms was compared using protein structures from a standard small-molecule docking test set. For nominal implementations of each algorithm, top-ranked Fast DPA predictions overlapped the true binding site 94% of the time, compared to 87% of the time for original DPA. In addition, per-protein recall statistics (fraction of binding-site residues that are among predicted residues were slightly better for Fast DPA. On the other hand, per-protein precision statistics (fraction of predicted residues that are among binding-site residues were slightly better using original DPA. Overall, the performance of Fast DPA in predicting ligand-binding-site residues was comparable to that of the original DPA algorithm. Conclusion Compared to the original DPA algorithm, the decreased run time with comparable performance makes Fast DPA well-suited for implementation on a web server and for high-throughput analysis.

Clay/Polyaniline Hybrid through Diazonium Chemistry: Conductive Nanofiller with Unusual Effects on Interfacial Properties of Epoxy Nanocomposites.

Science.gov (United States)

Jlassi, Khouloud; Chandran, Sarath; Poothanari, Mohammed A; Benna-Zayani, Mémia; Thomas, Sabu; Chehimi, Mohamed M

2016-04-12

The concept of conductive network structure in thermoset matrix without sacrificing the inherent mechanical properties of thermoset polymer (e.g., epoxy) is investigated here using "hairy" bentonite fillers. The latter were prepared through the in situ polymerization of aniline in the presence of 4-diphenylamine diazonium (DPA)-modified bentonite (B-DPA) resulting in a highly exfoliated bentonite-DPA/polyaniline (B-DPA/PANI). The nanocomposite filler was mixed with diglycidyl ether of bisphenol A (DGEBA), and the curing agent (4,4'-diaminodiphenylsulfone) (DDS) at high temperature in order to obtain nanocomposites through the conventional melt mixing technique. The role of B-DPA in the modification of the interface between epoxy and B-DPA/polyaniline (B-DPA/PANI) is investigated and compared with the filler B/PANI prepared without any diazonium modification of the bentonite. Synergistic improvement in dielectric properties and mechanical properties points to the fact that the DPA aryl groups from the diazonium precursor significantly modify the interface by acting as an efficient stress transfer medium. In DPA-containing nanocomposites, unique fibril formation was observed on the fracture surface. Moreover, dramatic improvement (210-220%) in fracture toughness of epoxy composite was obtained with B-DPA/PANI filler as compared to the weak improvement of 20-30% noted in the case of the B/PANI filler. This work shows that the DPA diazonium salt has an important effect on the improvement of the interfacial properties and adhesion of DGEBA and clay/PANI nanofillers.

High-level language computer architecture

CERN Document Server

Chu, Yaohan

1975-01-01

High-Level Language Computer Architecture offers a tutorial on high-level language computer architecture, including von Neumann architecture and syntax-oriented architecture as well as direct and indirect execution architecture. Design concepts of Japanese-language data processing systems are discussed, along with the architecture of stack machines and the SYMBOL computer system. The conceptual design of a direct high-level language processor is also described.Comprised of seven chapters, this book first presents a classification of high-level language computer architecture according to the pr

Other-than-high-level waste

International Nuclear Information System (INIS)

Bray, G.R.

1976-01-01

The main emphasis of the work in the area of partitioning transuranic elements from waste has been in the area of high-level liquid waste. But there are ''other-than-high-level wastes'' generated by the back end of the nuclear fuel cycle that are both large in volume and contaminated with significant quantities of transuranic elements. The combined volume of these other wastes is approximately 50 times that of the solidified high-level waste. These other wastes also contain up to 75% of the transuranic elements associated with waste generated by the back end of the fuel cycle. Therefore, any detailed evaluation of partitioning as a viable waste management option must address both high-level wastes and ''other-than-high-level wastes.''

Irradiation of structural materials in contact with lead bismuth eutectic in the high flux reactor

Energy Technology Data Exchange (ETDEWEB)

Magielsen, A.J., E-mail: magielsen@nrg.eu [Nuclear Research and Consultancy Group, Westerduinweg 3, Postbus 25, 1755 ZG Petten (Netherlands); Jong, M.; Bakker, T.; Luzginova, N.V.; Mutnuru, R.K.; Ketema, D.J.; Fedorov, A.V. [Nuclear Research and Consultancy Group, Westerduinweg 3, Postbus 25, 1755 ZG Petten (Netherlands)

2011-08-31

In the framework of the materials domain DEMETRA in the European Transmutation research and development project EUROTRANS, irradiation experiment IBIS has been performed in the High Flux Reactor in Petten. The objective was to investigate the synergystic effects of irradiation and lead bismuth eutectic exposure on the mechanical properties of structural materials and welds. In this experiment ferritic martensitic 9 Cr steel, austenitic 316L stainless steel and their welds have been irradiated for 250 Full Power Days up to a dose level of 2 dpa. Irradiation temperatures have been kept constant at 300 deg. C and 500 deg. C. During the post-irradiation test phase, tensile tests performed on the specimens irradiated at 300 deg. C have shown that the irradiation hardening of ferritic martensitic 9 Cr steel at 1.3 dpa is 254 MPa, which is in line with the irradiation hardening obtained for ferritic martensitic Eurofer97 steel investigated in the fusion program. This result indicates that no LBE interaction at this irradiation temperature is present. A visual inspection is performed on the specimens irradiated in contact with LBE at 500 deg. C and have shown blackening on the surface of the specimens and remains of LBE that makes a special cleaning procedure necessary before post-irradiation mechanical testing.

Characterization of Wet-Heat Inactivation of Single Spores of Bacillus Species by Dual-Trap Raman Spectroscopy and Elastic Light Scattering▿

Science.gov (United States)

Zhang, Pengfei; Kong, Lingbo; Setlow, Peter; Li, Yong-qing

2010-01-01

Dual-trap laser tweezers Raman spectroscopy (LTRS) and elastic light scattering (ELS) were used to investigate dynamic processes during high-temperature treatment of individual spores of Bacillus cereus, Bacillus megaterium, and Bacillus subtilis in water. Major conclusions from these studies included the following. (i) After spores of all three species were added to water at 80 to 90°C, the level of the 1:1 complex of Ca2+ and dipicolinic acid (CaDPA; ∼25% of the dry weight of the spore core) in individual spores remained relatively constant during a highly variable lag time (Tlag), and then CaDPA was released within 1 to 2 min. (ii) The Tlag values prior to rapid CaDPA release and thus the times for wet-heat killing of individual spores of all three species were very heterogeneous. (iii) The heterogeneity in kinetics of wet-heat killing of individual spores was not due to differences in the microscopic physical environments during heat treatment. (iv) During the wet-heat treatment of spores of all three species, spore protein denaturation largely but not completely accompanied rapid CaDPA release, as some changes in protein structure preceded rapid CaDPA release. (v) Changes in the ELS from individual spores of all three species were strongly correlated with the release of CaDPA. The ELS intensities of B. cereus and B. megaterium spores decreased gradually and reached minima at T1 when ∼80% of spore CaDPA was released, then increased rapidly until T2 when full CaDPA release was complete, and then remained nearly constant. The ELS intensity of B. subtilis spores showed similar features, although the intensity changed minimally, if at all, prior to T1. (vi) Carotenoids in B. megaterium spores' inner membranes exhibited two changes during heat treatment. First, the carotenoid's two Raman bands at 1,155 and 1,516 cm−1 decreased rapidly to a low value and to zero, respectively, well before Tlag, and then the residual 1,155-cm−1 band disappeared, in parallel

Electrochemical characterization of azo dye (E)-1-(4-((4-(phenylamino)phenyl)diazenyl)phenyl)ethanone (DPA)

International Nuclear Information System (INIS)

Surucu, Ozge; Abaci, Serdar; Seferoğlu, Zeynel

2016-01-01

Highlights: • Electrochemical characterization of azo dye DPA was performed. • Pencil graphite electrode was used as working electrode. • Cyclic voltammetry was used to determine the effect of scan rate and pH. • Chronoamperometry was used to determine diffusion constant. • Square wave voltammetry verified the results of cyclic voltammetry. - Abstract: An enormous range of possible dyes are available, especially as the starting molecules are readily available and cheap. As other dye classes become less viable from either an environmental or economic reasons, azo dyes come to the forefront. Therefore, electrochemical characterization of a novel synthesized azo dye (E)-1-(4-((4-(phenylamino) phenyl)diazenyl)phenyl)ethanone was achieved for the first time. Cyclic voltammetry, chronoamperometry and square wave voltammetry techniques were used to investigate the electrochemical behavior and electrocatalytic effect of azo dye (E)-1-(4-((4-(phenylamino) phenyl)diazenyl)phenyl)ethanone at pencil graphite electrode. Cyclic voltammograms were utilized to determine the effect of scan rate and pH on the peak current and peak potential. Chronoamperometry technique was used to determine diffusion constant, D and the type of adsorption isotherms. The kinetics parameters which were the apparent electron transfer rate constant, k s and charge transfer coefficient, α were calculated. Square wave voltammetry was used to verify responses of cyclic voltammetry technique.

Optimization of the synthesis of SAPO-11 for the methylation of naphthalene with methanol by varying templates and template content

Energy Technology Data Exchange (ETDEWEB)

Wang, Xiaoxiao [University of Chinese Academy of Sciences, Beijing (China); Zhang, Wei; Zhao, Liangfu; Xiang, Hongwei, E-mail: zw7234@sxicc.ac.cn, E-mail: lfzhao@sxicc.ac.cn [Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan (China); Guo, Shaoqing [Taiyuan University of Science and Technology, Taiyuan (China)

2013-07-15

SAPO-11 zeolites were successfully synthesized by using three different templates (diethylamine (DEA), di-n-propylamine (DPA) and di-isopropylamine (DIPA)) and varying DPA contents (nDPA/Al{sub 2}O{sub 3} = 0.8, 1.2, 1.6 and 2.0) under hydrothermal conditions. The samples were characterized by powder X-ray diffractometry (XRD), scanning electron microscopy (SEM), N{sub 2} adsorption-desorption, temperature programmed desorption of ammonia (NH{sub 3} -TPD) and {sup 29}Si magic angle spinning (MAS) nuclear magnetic resonance (NMR). The samples were also evaluated towards the methylation of naphthalene with methanol to produce 2,6-dimethylnaphthalene (2,6-DMN). XRD results indicated that the directing effect of the different templates for AEL (Aluminophosphate-ELeven) structure decreased in the order DPA > DEA > DIPA and the most suitable DPA content was nDPA/Al{sub 2}O{sub 3} = 1.2. N{sub 2} adsorption-desorption results showed that SAPO-11(DPA,1.2) exhibited the broadest pore size distribution, the highest BET specific surface area and the largest pore volume among all the SAPO-11 samples. SAPO-11(DPA,1.2) exhibited high catalytic performances in the methylation of naphthalene due to its high crystallinity, high external surface and broad pore size distribution. The pore structure of SAPO-11 zeolite, rather than its acidity, played an important role in achieving high catalytic performances in the methylation of naphthalene with methanol. (author)

[{sup 18}F]DPA-714, [{sup 18}F]PBR111 and [{sup 18}F]FEDAA1106-Selective radioligands for imaging TSPO 18 kDa with PET: Automated radiosynthesis on a TRACERLAb FX-FN synthesizer and quality controls

Energy Technology Data Exchange (ETDEWEB)

Kuhnast, Bertrand, E-mail: bertrand.kuhnast@cea.fr [CEA, I2BM, Service Hospitalier Frederic Joliot, 4 Place du General Leclerc, F-91401, Orsay Cedex (France); Damont, Annelaure; Hinnen, Francoise; Catarina, Tony; Demphel, Stephane; Le Helleix, Stephane; Coulon, Christine; Goutal, Sebastien; Gervais, Philippe; Dolle, Frederic [CEA, I2BM, Service Hospitalier Frederic Joliot, 4 Place du General Leclerc, F-91401, Orsay Cedex (France)

2012-03-15

Imaging of TSPO 18 kDa with PET is more and more considered as a relevant biomarker of inflammation in numerous diseases. Development of new radiotracers for TSPO 18 kDa has seen acceleration in the last years and the challenge today is to make available large amounts of such a radiotracer in compliance with GMP standards for application in humans. We present in this technical note automated productions of [{sup 18}F]DPA-714, [{sup 18}F]PBR111 and [{sup 18}F]FEDAA1106, three promising radiotracers for TSPO 18 kDa imaging, using a TRACERlab FX-FN synthesizer. This note also includes the quality control data of the validation batches for the manufacturing qualification of clinical production of [{sup 18}F]DPA-714. - Highlights: Black-Right-Pointing-Pointer Protein TSPO 18 kDa is recognized as a biomarker of inflammation involved in many diseases. Black-Right-Pointing-Pointer Radiotracers targeting TSPO prepared in compliance with GMPs are mandatory as new imaging tools. Black-Right-Pointing-Pointer An automated radiosynthesis of promising radiotracers and full QC have been implemented.

Low bone mineral density in COPD patients with osteoporosis is related to low daily physical activity and high COPD assessment test scores

Directory of Open Access Journals (Sweden)

Liu WT

2015-09-01

, all P<0.05 and T-score (r=0.471, 0.531, 0.459, respectively, all P<0.05, whereas CAT scores were significantly negatively correlated with (total hip and femoral neck BMD (r=-0.412, -0.552, respectively, P<0.05 and (lumbar spine, total hip, and femoral neck T-score (r=-0.389, -0.429, -0.543, respectively, P<0.05. Low femoral neck BMD in COPD patients was related to high CAT scores. Our results show no significant difference in desaturation index, low SpO2, and inflammatory markers (IL-6, TNF-α, IL-8/CXCL8, CRP, and 8-isoprostane between the two groups. Chest physicians should be aware that COPD patients with OP have low DPA and high CAT scores.Keywords: chronic obstructive pulmonary disease, osteoporosis, daily physical activity, COPD assessment test, bone mineral density

The management of high-level radioactive wastes

International Nuclear Information System (INIS)

Lennemann, Wm.L.

1979-01-01

The definition of high-level radioactive wastes is given. The following aspects of high-level radioactive wastes' management are discussed: fuel reprocessing and high-level waste; storage of high-level liquid waste; solidification of high-level waste; interim storage of solidified high-level waste; disposal of high-level waste; disposal of irradiated fuel elements as a waste

Strain-induced phase transformation at the surface of an AISI-304 stainless steel irradiated to 4.4 dpa and deformed to 0.8% strain

Energy Technology Data Exchange (ETDEWEB)

Gussev, M.N., E-mail: gussevmn@ornl.gov; Field, K.G.; Busby, J.T.

2014-03-15

Surface relief due to localized deformation in a 4.4-dpa neutron-irradiated AISI 304 stainless steel was investigated using scanning electron microscopy coupled with electron backscattering diffraction and scanning transmission electron microscopy. It was found a body-centered-cubic (BCC) phase (deformation-induced martensite) had formed at the surface of the deformed specimen along the steps generated from dislocation channels. Martensitic hill-like formations with widths of ∼1 μm and depths of several microns were observed at channels with heights greater than ∼150 nm above the original surface. Martensite at dislocation channels was observed in grains along the [0 0 1]–[1 1 1] orientation but not in those along the [1 0 1] orientation.

Strain-induced phase transformation at the surface of an AISI-304 stainless steel irradiated to 4.4 dpa and deformed to 0.8% strain

International Nuclear Information System (INIS)

Gussev, M.N.; Field, K.G.; Busby, J.T.

2014-01-01

Surface relief due to localized deformation in a 4.4-dpa neutron-irradiated AISI 304 stainless steel was investigated using scanning electron microscopy coupled with electron backscattering diffraction and scanning transmission electron microscopy. It was found a body-centered-cubic (BCC) phase (deformation-induced martensite) had formed at the surface of the deformed specimen along the steps generated from dislocation channels. Martensitic hill-like formations with widths of ∼1 μm and depths of several microns were observed at channels with heights greater than ∼150 nm above the original surface. Martensite at dislocation channels was observed in grains along the [0 0 1]–[1 1 1] orientation but not in those along the [1 0 1] orientation

PET molecular imaging of peripheral and central inflammatory processes targeting the TSPO 18 kDa

International Nuclear Information System (INIS)

Bernards, Nicholas

2014-01-01

The purpose of this study was to determine the in vivo potential of the TSPO 18 kDa as a bio-marker of inflammation, with the use of its radioligand [ 18 F]DPA-714, to non-invasively quantify the inflammatory state within the scope of various pathologies. Multiple animal models of various inflammatory diseases, to include: inflammatory bowel disease, neuro-inflammation, and septic shock, were developed and put in place by adapted measures. The animals well-being and the subsequent inflammation was evaluated. The inflammatory state was measured using quantitative PET imaging with the TSPO radioligand [ 18 F]DPA-714 and correlated to the expression of conventional inflammatory markers using microscopy. Based on the observed data, we were able to distinguish control groups from treated groups when using [ 18 F]DPA-714. This TSPO radioligand permitted us to quantify the inflammatory level and to observe evolutionary changes in the inflammatory state of the disease in multiple models. The PET results, using the [ 18 F]DPA-714 signal was correlated with an increased TSPO expression at cellular level. Results indicate that [ 18 F]DPA-714 is a suitable tracer for studying inflammation of multiple diseases. [ 18 F]DPA-714 could be a good molecular probe to non-invasively evaluate the level and localization of inflammation. Moreover, in vivo imaging using this TSPO ligand is potentially a powerful tool to stage and certainly to follow the evolution and therapeutic efficiency at molecular level in inflammatory diseases. (author) [fr

RPython high-level synthesis

Science.gov (United States)

Cieszewski, Radoslaw; Linczuk, Maciej

2016-09-01

The development of FPGA technology and the increasing complexity of applications in recent decades have forced compilers to move to higher abstraction levels. Compilers interprets an algorithmic description of a desired behavior written in High-Level Languages (HLLs) and translate it to Hardware Description Languages (HDLs). This paper presents a RPython based High-Level synthesis (HLS) compiler. The compiler get the configuration parameters and map RPython program to VHDL. Then, VHDL code can be used to program FPGA chips. In comparison of other technologies usage, FPGAs have the potential to achieve far greater performance than software as a result of omitting the fetch-decode-execute operations of General Purpose Processors (GPUs), and introduce more parallel computation. This can be exploited by utilizing many resources at the same time. Creating parallel algorithms computed with FPGAs in pure HDL is difficult and time consuming. Implementation time can be greatly reduced with High-Level Synthesis compiler. This article describes design methodologies and tools, implementation and first results of created VHDL backend for RPython compiler.

A Novel UV-Shielding and Transparent Polymer Film: When Bioinspired Dopamine-Melanin Hollow Nanoparticles Join Polymers.

Science.gov (United States)

Wang, Yang; Su, Jing; Li, Ting; Ma, Piming; Bai, Huiyu; Xie, Yi; Chen, Mingqing; Dong, Weifu

2017-10-18

Ultraviolet (UV) light is known to be harmful to human health and cause organic materials to undergo photodegradation. In this Research Article, bioinspired dopamine-melanin solid nanoparticles (Dpa-s NPs) and hollow nanoparticles (Dpa-h NPs) as UV-absorbers were introduced to enhance the UV-shielding performance of polymer. First, Dpa-s NPs were synthesized through autoxidation of dopamine in alkaline aqueous solution. Dpa-h NPs were prepared by the spontaneous oxidative polymerization of dopamine solution onto polystyrene (PS) nanospheres template, followed by removal of the template. Poly(vinyl alcohol) (PVA)/Dpa nanocomposite films were subsequently fabricated by a simple casting solvent. UV irradiation protocols were set up, allowing selective study of the extra-shielding effects of Dpa-s versus Dpa-h NPs. In contrast to PVA/Dpa-s films, PVA/Dpa-h films exhibit stronger UV-shielding capabilities and can almost block the complete UV region (200-400 nm). The excellent UV-shielding performance of the PVA/Dpa-h films mainly arises from multiple absorption because of the hollow structure and large specific area of Dpa-h NPs. Moreover, the wall thickness of Dpa-h NPs can be simply controlled from 28 to 8 nm, depending on the ratio between PS and dopamine. The resulting films with Dpa-h NPs (wall thickness = ∼8 nm) maintained relatively high transparency to visible light because of the thinner wall thickness. The results indicate that the prepared Dpa-h NPs can be used as a novel UV absorber for next-generation transparent UV-shielding materials.

Evolution of secondary-phase precipitates during annealing of the 12Kh18N9T steel irradiated with neutrons to a dose of 5 DPA

Science.gov (United States)

Tsai, K. V.; Maksimkin, O. P.; Turubarova, L. G.

2007-03-01

The formation and evolution of thermally-induced secondary precipitates in an austenitic stainless steel 12Kh18N9T irradiated in the core of a laboratory reactor VVR-K to a dose of 5 dpa and subjected to post-radiation isochronous annealings for 1 h in a temperature range from 450 to 1050°C have been studied using transmission electron microscopy (TEM) and microhardness measurements. It has been shown that the formation of stitch (secondary) titanium carbides and M 23C6 carbides at grain and twin boundaries after annealing at 1050°C is preceded by a complex evolution of fineparticles of secondary phases (titanium carbides and nitrides) precipitated at dislocation loops and dislocations during annealing at temperatures above 750°C.

High potassium level

Science.gov (United States)

... level is very high, or if you have danger signs, such as changes in an ECG . Emergency ... Seifter JL. Potassium disorders. In: Goldman L, Schafer AI, eds. Goldman-Cecil Medicine . 25th ed. Philadelphia, PA: ...

High-level Petri Nets

DEFF Research Database (Denmark)

various journals and collections. As a result, much of this knowledge is not readily available to people who may be interested in using high-level nets. Within the Petri net community this problem has been discussed many times, and as an outcome this book has been compiled. The book contains reprints...... of some of the most important papers on the application and theory of high-level Petri nets. In this way it makes the relevant literature more available. It is our hope that the book will be a useful source of information and that, e.g., it can be used in the organization of Petri net courses. To make......High-level Petri nets are now widely used in both theoretical analysis and practical modelling of concurrent systems. The main reason for the success of this class of net models is that they make it possible to obtain much more succinct and manageable descriptions than can be obtained by means...

Perturbing Tandem Energy Transfer in Luminescent Heterobinuclear Lanthanide Coordination Polymer Nanoparticles Enables Real-Time Monitoring of Release of the Anthrax Biomarker from Bacterial Spores.

Science.gov (United States)

Gao, Nan; Zhang, Yunfang; Huang, Pengcheng; Xiang, Zhehao; Wu, Fang-Ying; Mao, Lanqun

2018-06-05

Lanthanide-based luminescent sensors have been widely used for the detection of the anthrax biomarker dipicolinic acid (DPA). However, mainly based on DPA sensitization to the lanthanide core, most of them failed to realize robust detection of DPA in bacterial spores. We proposed a new strategy for reliable detection of DPA by perturbing a tandem energy transfer in heterobinuclear lanthanide coordination polymer nanoparticles simply constructed by two kinds of lanthanide ions, Tb 3+ and Eu 3+ , and guanosine 5'-monophosphate. This smart luminescent probe was demonstrated to exhibit highly sensitive and selective visual luminescence color change upon exposure to DPA, enabling accurate detection of DPA in complex biosystems such as bacterial spores. DPA release from bacterial spores on physiological germination was also successfully monitored in real time by confocal imaging. This probe is thus expected to be a powerful tool for efficient detection of bacterial spores in responding to anthrax threats.

Highly efficient and stable cyclometalated ruthenium(II) complexes as sensitizers for dye-sensitized solar cells

International Nuclear Information System (INIS)

Huang, Jian-Feng; Liu, Jun-Min; Su, Pei-Yang; Chen, Yi-Fan; Shen, Yong; Xiao, Li-Min; Kuang, Dai-Bin; Su, Cheng-Yong

2015-01-01

Highlights: • Four novel thiocyanate-free cyclometalated ruthenium sensitizer were conveniently synthesized. • The D-CF 3 -sensitized DSSCs show higher efficiency compared to N719 based cells. • The DSSCs based on D-CF 3 and D-bisCF 3 sensitizers exhibit excellent long-term stability. • The diverse cyclometalated Ru complexes can be developed as high-performance sensitizers for use in DSSC. - Abstract: Four novel thiocyanate-free cyclometallted Ru(II) complexes, D-bisCF 3 , D-CF 3 , D-OMe, and D-DPA, with two 4,4′-dicarboxylic acid-2,2′-bipyridine together with a functionalized phenylpyridine ancillary ligand, have been designed and synthesized. The effect of different substituents (R = bisCF 3 , CF 3 , OMe, and DPA) on the ancillary C^N ligand on the photophysical properties and photovoltaic performance is investigated. Under standard global AM 1.5 solar conditions, the device based on D-CF 3 sensitizer gives a higher conversion efficiency of 8.74% than those based on D-bisCF 3 , D-OMe, and D-DPA, which can be ascribed to its broad range of visible light absorption, appropriate localization of the frontier orbitals, weak hydrogen bonds between -CF 3 and -OH groups at the TiO 2 surface, moderate dye loading on TiO 2 , and high charge collection efficiency. Moreover, the D-bisCF 3 and D-CF 3 based DSSCs exhibit good stability under 100 mW cm −2 light soaking at 60 °C for 400 h

Accuracy of dual photon absorptiometry for assessment of bone mineral and body composition

International Nuclear Information System (INIS)

Aoki, Manabu; Iwamura, Akira; Goto, Eisuke; Mori, Yutaka; Kawakami, Kenji; Soshi, Shigeru

1991-01-01

Accuracy of bone mineral measurement by the dual photon absorptiometry (DPA) was studied in comparison to ashed bone mineral (ash) on the lumbar spine of 23 cada vars. There was a high correlation (r=0.896) between the value of DPA and ash weight. Bone mineral content in the radius by the single photon absorptiometry (SPA) did not correlate to bone mineral density (BMD) by DPA in the patients with hemodialysis. SPA may be less useful to assess BMD of the whole body. Fat mass and lean mass measured by DPA were well correlated to the value obtained by the electrical impedance method. Precision in measurement of fat mass and lean mass was also confirmed by the electrical impedance method. These results suggest that DPA has a high precision for measurements of the bone mineral and the body composition. (author)

Delinquent peer affiliation as an etiological moderator of childhood delinquency.

Science.gov (United States)

Burt, S A; Klump, K L

2013-06-01

Prior research has indicated that affiliation with delinquent peers activates genetic influences on delinquency during adolescence. However, because other studies have indicated that the socializing effects of delinquent peers vary dramatically across childhood and adolescence, it is unclear whether delinquent peer affiliation (DPA) also moderates genetic influences on delinquency during childhood. Method The current study sought to evaluate whether and how DPA moderated the etiology of delinquency in a sample of 726 child twins from the Michigan State University Twin Registry (MSUTR). The results robustly supported etiological moderation of childhood delinquency by DPA. However, this effect was observed for shared environmental, rather than genetic, influences. Shared environmental influences on delinquency were found to be several-fold larger in those with higher levels of DPA as compared to those with lower levels. This pattern of results persisted even when controlling for the overlap between delinquency and DPA. Our findings bolster prior work in suggesting that, during childhood, the association between DPA and delinquency is largely (although not solely) attributable to the effects of socialization as compared to selection. They also suggest that the process of etiological moderation is not specific to genetic influences. Latent environmental influences are also amenable to moderation by measured environmental factors.

The response of dispersion-strengthened copper alloys to high fluence neutron irradiation at 415 degrees C

International Nuclear Information System (INIS)

Edwards, D.J.; Newkirk, J.W.; Garner, F.A.; Hamilton, M.L.; Nadkarni, A.; Samal, P.

1993-01-01

Various oxide-dispersion-strengthened copper alloys have been irradiated to 150 dpa at 415 degrees C in the Fast Flux Test Facility (FFTF). The Al 2 O 3 -strengthened GlidCop TM alloys, followed closely by a HfO 2 -strengthened alloy, displayed the best swelling resistance, electrical conductivity, and tensile properties. The conductivity of the HfO 2 -strengthened alloy reached a plateau at the higher levels of irradiation, instead of exhibiting the steady decrease in conductivity observed in the other alloys. A high initial oxygen content results in significantly higher swelling for a series of castable oxide-dispersion-strengthened alloys, while a Cr 2 O 3 -strengthened alloy showed poor resistance to radiation

Hardness of AISI type 410 martensitic steels after high temperature irradiation via nanoindentation

Science.gov (United States)

Waseem, Owais Ahmed; Jeong, Jong-Ryul; Park, Byong-Guk; Maeng, Cheol-Soo; Lee, Myoung-Goo; Ryu, Ho Jin

2017-11-01

The hardness of irradiated AISI type 410 martensitic steel, which is utilized in structural and magnetic components of nuclear power plants, is investigated in this study. Proton irradiation of AISI type 410 martensitic steel samples was carried out by exposing the samples to 3 MeV protons up to a 1.0 × 1017 p/cm2 fluence level at a representative nuclear reactor coolant temperature of 350 °C. The assessment of deleterious effects of irradiation on the micro-structure and mechanical behavior of the AISI type 410 martensitic steel samples via transmission electron microscopy-energy dispersive spectroscopy and cross-sectional nano-indentation showed no significant variation in the microscopic or mechanical characteristics. These results ensure the integrity of the structural and magnetic components of nuclear reactors made of AISI type 410 martensitic steel under high-temperature irradiation damage levels up to approximately 5.2 × 10-3 dpa.

Effect of helium and DPA's on tensile properties of V-5Ti and V-3Ti-1Si

International Nuclear Information System (INIS)

Witzenburg, W. van; Vries, E. de.

1991-02-01

Specimens of the alloys V-5Ti and V-3Ti-1Si were irradiated in a mixed-spectrum fission reactor in reactor grade liquid sodium to a fast neutron fluence of 3.8 x 10 25 m -2 (E>0.1 MeV), which corresponds to 6.2 dpa. Irradiation temperatures were 500, 600 and 700 deg C. Some of the specimens were pre-injected with helium to 100 appm at approx 50 deg C by means of a cyclotron. In addition, part of the specimens were doped with boron-10 to concentrations of 100 and 600 appm. Tensile testing, at temperatures equal to the irradiation temperatures and at a strain rate of 10 -4 s -1 , showed an increase in strength and reduced elongation at 500 deg C and to a lesser extent at 600 deg C. These changes are caused by displacement damage. Helium, pre-injected as well as produced by transmutation of boron-10, did not have a significant influence on the tensile properties. Cavities seen in the irradiated materials at low concentrations, were not preferentially located on grain boundaries. There was no apparent deleterious effect of lithium, which is also a transmutation product of boron-10. (author). 12 refs.; 8 figs.; 3 tabs

A mobile phone application to stimulate daily physical activity in patients with chronic obstructive pulmonary disease: development, feasibility and pilot studies

NARCIS (Netherlands)

Jan-Willem J. Lammers; Dr. H.S.M. Kort; Sigrid N.W. Vorrink; Thierry Troosters

2016-01-01

Background: Patients with chronic obstructive pulmonary disease (COPD) demonstrate reduced levels of daily physical activity (DPA) compared to healthy controls. This results in a higher risk of hospital admission and shorter survival. Performing regular DPA reduces these risks. Objective: To develop

Spatial investigation of the elemental distribution in Wilson's disease liver after d-penicillamine treatment by LA-ICP-MS.

Science.gov (United States)

Hachmöller, Oliver; Zibert, Andree; Zischka, Hans; Sperling, Michael; Groba, Sara Reinartz; Grünewald, Inga; Wardelmann, Eva; Schmidt, Hartmut H-J; Karst, Uwe

2017-12-01

At present, the copper chelator d-penicillamine (DPA) is the first-line therapy of Wilson's disease (WD), which is characterized by an excessive copper overload. Lifelong DPA treatments aim to reduce the amount of detrimental excess copper retention in the liver and other organs. Although DPA shows beneficial effect in many patients, it may cause severe adverse effects. Despite several years of copper chelation therapy, discontinuation of DPA therapy can be linked to a rapidly progressing liver failure, indicating a high residual liver copper load. In order to investigate the spatial distribution of remaining copper and additional elements, such as zinc and iron, in rat and human liver samples after DPA treatment, a high resolution (spotsize of 10μm) laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) imaging method was applied. Untreated LPP -/- rats, an established animal model for WD, appeared with a high overall copper concentration and a copper distribution of hotspots distributed over the liver tissue. In contrast, a low (>2-fold decreased) overall copper concentration was detected in liver of DPA treated animals. Importantly, however, copper distribution was highly inhomogeneous with lowest concentrations in direct proximity to blood vessels, as observed using novel zonal analysis. A human liver needle biopsy of a DPA treated WD patient substantiated the finding of an inhomogeneous copper deposition upon chelation therapy. In contrast, comparatively homogenous distributions of zinc and iron were observed. Our study indicates that a high resolution LA-ICP-MS analysis of liver samples is excellently suited to follow efficacy of chelator therapy in WD patients. Copyright © 2017 Elsevier GmbH. All rights reserved.

Correlation between physical and mechanical properties changes of austenitic steel ChS-68 under high dose irradiation

International Nuclear Information System (INIS)

Ershova, O.V.; Shcherbakov, E.N.; Evseev, M.V.; Shihkalev, V.S.; Kozlov, A.V.; Garner, F.

2007-01-01

Full text of publication follows: It is well known that void swelling at high levels exerts significant influence on physical, mechanical and creep properties of austenitic steels. For many fusion or fission reactor concepts it is desirable not only to characterize these relationships but also to develop nondestructive measurements to measure swelling without removing components from the reactor. Previous studies at this institute have shown that swelling can be estimated using changes in elastic moduli via ultrasonic techniques and electrical resistivity via electro-resistive methods. In this study we examined two pin claddings of ChS-68 (Fe-16Cr-15Ni-2Mo-2Mn-Ti-Si irradiated at somewhat different dpa rates in the high-flux BN-600 fast reactor, with temperatures ranging from 370-590 deg. C to maximum doses of 69 and 78 dpa. After removing the fuel, ring specimens were cut and used to conduct tensile tests using a standardized ring-pull test. Changes in density, elastic moduli and electrical resistivity were performed prior to tensile testing. Maximum swelling levels in the two pins reached ∼7 and 12%, with strong consequences observed in mechanical properties. At the higher swelling level there was a total loss of ductility over a significant middle portion of the pin. In both the lower swelling and higher swelling pins there was a clear correlation between the local swelling along the pin length with declining ultimate strength and total elongation, providing clear evidence of void-induced embrittlement. Changes in electrical resistivity and elastic moduli correlated well with predictions based on void swelling at lower irradiation temperatures where precipitates were not a dominant part of the radiation-induced microstructure. At higher temperatures large precipitates of Ni-rich radiation-stable phases are a large portion of the microstructure and void-based predictions of elastic moduli and electrical resistivity do not agree well with the measurements

Radiation-induced grain subdivision and bubble formation in U3Si2 at LWR temperature

Science.gov (United States)

Yao, Tiankai; Gong, Bowen; He, Lingfeng; Harp, Jason; Tonks, Michael; Lian, Jie

2018-01-01

U3Si2, an advanced fuel form proposed for light water reactors (LWRs), has excellent thermal conductivity and a high fissile element density. However, limited understanding of the radiation performance and fission gas behavior of U3Si2 is available at LWR conditions. This study explores the irradiation behavior of U3Si2 by 300 keV Xe+ ion beam bombardment combining with in-situ transmission electron microscopy (TEM) observation. The crystal structure of U3Si2 is stable against radiation-induced amorphization at 350 °C even up to a very high dose of 64 displacements per atom (dpa). Grain subdivision of U3Si2 occurs at a relatively low dose of 0.8 dpa and continues to above 48 dpa, leading to the formation of high-density nanoparticles. Nano-sized Xe gas bubbles prevail at a dose of 24 dpa, and Xe bubble coalescence was identified with the increase of irradiation dose. The volumetric swelling resulting from Xe gas bubble formation and coalescence was estimated with respect to radiation dose, and a 2.2% volumetric swelling was observed for U3Si2 irradiated at 64 dpa. Due to extremely high susceptibility to oxidation, the nano-sized U3Si2 grains upon radiation-induced grain subdivision were oxidized to nanocrystalline UO2 in a high vacuum chamber for TEM observation, eventually leading to the formation of UO2 nanocrystallites stable up to 80 dpa.

Calculation of the displacement cross sections and the DPA distribution in hydrogenated amorphous silicon semiconductors detectors in medical digital imaging applications

International Nuclear Information System (INIS)

Leyva Fabelo, Antonio; Piñera Hernández, Ibrahin; Shtejer Díaz, Katerin; Abreu Alfonso, Yamiel; Cruz Inclán, Carlos Manuel

2007-01-01

In present paper the dependence of the displacement cross sections of the different species of atoms in the a-Si:H structure, with the energy of the secondary electrons generated by the X-rays of the typical energies using in medical imaging applications, was calculated using the Mott-McKinley- Feshbach approach. It was verified that for electron energies higher than 1.52 keV it is possible the occurrence of hydrogen atoms displacements, while for the silicon atoms the threshold energy is 126 keV. These results were compared with those obtained for similar detectors but developed with crystalline silicon. With the use of the mathematical simulation of the radiation transport in the matter, the energy spectrum of the secondary electrons was calculated in order to estimate the number of atomic displacements, which take place in the semiconducting amorphous device in working regime. The spatial distribution of the dpa in the detectors volume, as well as its behavior with the depth in the work region are presented and discussed in the text. (author)

Fluoxetine potentiation of omega-3 fatty acid antidepressant effect: evaluating pharmacokinetic and brain fatty acid-related aspects in rodents.

Science.gov (United States)

Laino, Carlos Horacio; Garcia, Pilar; Podestá, María Fernanda; Höcht, Christian; Slobodianik, Nora; Reinés, Analía

2014-10-01

We previously reported that combined fluoxetine administration at antidepressant doses renders additive antidepressant effects, whereas non-antidepressant doses potentiate the omega-3 fatty acid antidepressant effect. In the present study, we aimed to evaluate putative pharmacokinetic and brain omega-3 fatty acid-related aspects for fluoxetine potentiation of omega-3 fatty acid antidepressant effect in rats. Coadministration of omega-3 fatty acids with a non-antidepressant dose of fluoxetine (1 mg/kg day) failed to affect both brain fluoxetine concentration and norfluoxetine plasma concentration profile. Fluoxetine plasma concentrations remained below the sensitivity limit of the detection method. Either antidepressant (10 mg/kg day) or non-antidepressant (1 mg/kg day) doses of fluoxetine in combination with omega-3 fatty acids increased hippocampal docosapentaenoic acid (DPA, 22:5 omega-3) levels. Although individual treatments had no effects on DPA concentration, DPA increase was higher when omega-3 were combined with the non-antidepressant dose of fluoxetine. Chronic DPA administration exerted antidepressant-like effects in the forced swimming test while increasing hippocampal docosahexaenoic (22:6 omega-3) and DPA levels. Our results suggest no pharmacokinetic interaction and reveal specific hippocampal DPA changes after fluoxetine and omega-3 combined treatments in our experimental conditions. The DPA role in the synergistic effect of fluoxetine and omega-3 combined treatments will be for sure the focus of future studies. © 2014 Wiley Periodicals, Inc. and the American Pharmacists Association J Pharm Sci 103:3316-3325, 2014. © 2014 Wiley Periodicals, Inc. and the American Pharmacists Association.

Microstructural examination of 12% Cr martensitic stainless steel after irradiation at elevated temperatures in FFTF [Fast Flux Test Facility

International Nuclear Information System (INIS)

Hsu, Chen-Yih; Gelles, D.S.; Lechtenberg, T.A.

1986-06-01

A remelted 12% Cr martensitic stainless steel (HT-9) has been examined by transmission electron microscopy before and after irradiation in the Materials Open Test Assembly (MOTA) of the Fast Flux Test Facility (FFTF). The irradiation temperatures were 365,420, 520, and 600 degree C with the fluences as high as 7.3 x 10 22 n/cm 2 (E > 0.1 MeV) or 34 dpa. The extracted precipitates from each specimen were identified using x-ray microanalysis and selected area diffraction. The precipitates in the unirradiated condition were primarily M 23 C 6 carbides, which formed at martensite lath and prior austenite grain boundaries. During irradiation at elevated temperatures, small amounts of other phases formed, which were tentatively identified as the chromium-rich α', the nickel-silicon rich G-phase, and the intermetallic Chi phase. Irradiation-induced voids were observed only in specimens irradiated at 420 degree C to a dose of 34 dpa; no voids were found for specimens irradiated at 365, 520, and 600 degree C (∼11, ∼34, and ∼34 dpa). These results are not in agreement with previous experiments in that voids have not been reported in this alloy at relatively high fluence level (∼67 dpa) following irradiation in another fast-spectrum reactor (EBR.II). This is, however, the first observation following FFTF irradiation. The present results indicate that cavities can form in HT-9 at modest fluence levels even without significant generation of helium. Hence, the cavity formation in this class of ferritic alloys is not simply caused by helium generation but rather more complex mechanisms. 12 refs., 2 figs., 3 tabs

EAP high-level product architecture

DEFF Research Database (Denmark)

Guðlaugsson, Tómas Vignir; Mortensen, Niels Henrik; Sarban, Rahimullah

2013-01-01

EAP technology has the potential to be used in a wide range of applications. This poses the challenge to the EAP component manufacturers to develop components for a wide variety of products. Danfoss Polypower A/S is developing an EAP technology platform, which can form the basis for a variety...... of EAP technology products while keeping complexity under control. High level product architecture has been developed for the mechanical part of EAP transducers, as the foundation for platform development. A generic description of an EAP transducer forms the core of the high level product architecture...... the function of the EAP transducers to be changed, by basing the EAP transducers on a different combination of organ alternatives. A model providing an overview of the high level product architecture has been developed to support daily development and cooperation across development teams. The platform approach...

High Level Radioactive Waste Management

International Nuclear Information System (INIS)

1991-01-01

The proceedings of the second annual international conference on High Level Radioactive Waste Management, held on April 28--May 3, 1991, Las Vegas, Nevada, provides information on the current technical issue related to international high level radioactive waste management activities and how they relate to society as a whole. Besides discussing such technical topics as the best form of the waste, the integrity of storage containers, design and construction of a repository, the broader social aspects of these issues are explored in papers on such subjects as conformance to regulations, transportation safety, and public education. By providing this wider perspective of high level radioactive waste management, it becomes apparent that the various disciplines involved in this field are interrelated and that they should work to integrate their waste management activities. Individual records are processed separately for the data bases

Development of martensitic steels for high neutron damage applications

International Nuclear Information System (INIS)

Gelles, D.S.

1998-01-01

Martensitic stainless steels have been developed for both in-core applications in advanced liquid metal fast breeder reactors (LMFBR) and for first wall and structural materials applications for commercial fusion reactors. It can now be shown that these steels can be expected to maintain properties to levels as high as 175 or 200 dpa, respectively. The 12Cr-1Mo-0.5W-0.2C alloy HT-9 has been extensively tested for LMFBR applications and shown to resist radiation damage, providing a creep and swelling resistant alternative to austenitic steels. Degradation of fracture toughness and Charpy impact properties have been observed, but properties are sufficient to provide reliable service. In comparison, alloys with lower chromium contents are found to decarburize in contact with liquid sodium and are therefore not recommended. Tungsten stabilized martensitic stainless steels have appropriate properties for fusion applications. Radioactivity levels are being less than 500 years after service, radiation damage resistance is excellent, including impact properties, and swelling is modest. This report describes the history of the development effort. (author)

Development of martensitic steels for high neutron damage applications

Science.gov (United States)

Gelles, D. S.

1996-12-01

Martensitic stainless steels have been developed for both in-core applications in advanced liquid metal fast breeder reactors (LMFBR) and for first wall and structural materials applications for commercial fusion reactors. It can now be shown that these steels can be expected to maintain properties to levels as high as 175 or 200 dpa, respectively. The 12Cr1Mo0.5W0.2C alloy HT-9 has been extensively tested for LMFBR applications and shown to resist radiation damage, providing a creep and swelling resistant alternative to austenitic steels. Degradation of fracture toughness and Charpy impact properties have been observed, but properties are sufficient to provide reliable service. In comparison, alloys with lower chromium contents are found to decarburize in contact with liquid sodium and are therefore not recommended. Tungsten stabilized martensitic stainless steels have appropriate properties for fusion applications. Radioactivity levels are benign less than 500 years after service, radiation damage resistance is excellent, including impact properties, and swelling is modest. This report describes the history of the development effort.

Characterization of irradiation damage distribution near TiO2/SrTiO3 interfaces using coherent acoustic phonon interferometry

International Nuclear Information System (INIS)

Yarotski, Dmitry; Yan Li; Jia Quanxi; Taylor, Antoinette J.; Fu Engang; Wang Yongqiang; Uberuaga, Blas P.

2012-01-01

We apply ultrafast coherent acoustic phonon interferometry to characterize the distribution of the radiation damage near the TiO 2 /SrTiO 3 interfaces. We show that the optical and mechanical properties of anatase TiO 2 remain unaffected by the radiation dosages in the 0.1÷5 dpa (displacements per atom) range, while the degraded optical response indicates a significant defect accumulation in the interfacial region of SrTiO 3 at 0.1 dpa and subsequent amorphization at 3 dpa. Comparison between the theoretical simulations and the experimental results reveals an almost threefold reduction of the sound velocity in the irradiated SrTiO 3 layer with peak damage levels of 3 and 5 dpa.

Disposal of high level and intermediate level radioactive wastes

International Nuclear Information System (INIS)

Flowers, R.H.

1991-01-01

The waste products from the nuclear industry are relatively small in volume. Apart from a few minor gaseous and liquid waste streams, containing readily dispersible elements of low radiotoxicity, all these products are processed into stable solid packages for disposal in underground repositories. Because the volumes are small, and because radioactive wastes are latecomers on the industrial scene, a whole new industry with a world-wide technological infrastructure has grown up alongside the nuclear power industry to carry out the waste processing and disposal to very high standards. Some of the technical approaches used, and the Regulatory controls which have been developed, will undoubtedly find application in the future to the management of non-radioactive toxic wastes. The repository site outlined would contain even high-level radioactive wastes and spent fuels being contained without significant radiation dose rates to the public. Water pathway dose rates are likely to be lowest for vitrified high-level wastes with spent PWR fuel and intermediate level wastes being somewhat higher. (author)

Heat transfer in high-level waste management

International Nuclear Information System (INIS)

Dickey, B.R.; Hogg, G.W.

1979-01-01

Heat transfer in the storage of high-level liquid wastes, calcining of radioactive wastes, and storage of solidified wastes are discussed. Processing and storage experience at the Idaho Chemical Processing Plant are summarized for defense high-level wastes; heat transfer in power reactor high-level waste processing and storage is also discussed

Inactivation of Bacillus subtilis spores by high pressure CO2 with high temperature.

Science.gov (United States)

Rao, Lei; Xu, Zhenzhen; Wang, Yongtao; Zhao, Feng; Hu, Xiaosong; Liao, Xiaojun

2015-07-16

The objective of this study was to investigate the inactivation of the Bacillus subtilis spores by high pressure CO2 combined with high temperature (HPCD+HT) and to analyze the clumping effect of the spores on their HPCD+HT resistance. The spores of B. subtilis were subjected to heat at 0.1 MPa and HPCD at 6.5-25 MPa, and 82 °C, 86 °C, and 91 °C for 0-120 min. The spores were effectively inactivated by HPCD+HT, but a protective effect on the spores was also found, which was closely correlated to the pressure, temperature and time. The spores treated by HPCD+HT at 6.5 and 10 MPa exhibited a two-stage inactivation curve of shoulder and log-linear regions whereas the spores at 15-25 MPa exhibited a three-stage inactivation curve of shoulder, log-linear and tailing regions, and these curves were well fitted to the Geeraerd model. Approximately 90% of pyridine-2,6-dicarboxylic acid (DPA) was released after HPCD+HT and the 90% DPA release time depend on the pressure and temperature. Moreover, the spore clumping in suspensions was examined by dynamic light scattering. The particle size of the spore suspensions increased with the increase of pressure, temperature and time, indicating the spore clumping. 0.1% Tween 80 as a surfactant inhibited the spore clumping and increased the inactivation ratio of the spores by HPCD+HT. These results indicated that the spore clumping enhanced the spores' resistance to HPCD+HT and induced a protective effect. Copyright © 2015 Elsevier B.V. All rights reserved.

Solute segregation and void formation in ion-irradiated vanadium-base alloys

International Nuclear Information System (INIS)

Loomis, B.A.; Smith, D.L.

1985-01-01

The radiation-induced segregation of solute atoms in the V-15Cr-5Ti alloys was determined after either single- dual-, or helium implantation followed by single-ion irradiation at 725 0 C to radiation damage levels ranging from 103 to 169 dpa. Also, the effect of irradiation temperature (600-750 0 C) on the microstructure in the V-15Cr-5Ti alloy was determined after single-ion irradiation to 200 and 300 dpa. The solute segregation results for the single- and dual-ion irradiated alloy showed that the simultaneous production of irradiation damage and deposition of helium resulted in enhanced depletion of Cr solute and enrichment of Ti, C and S solute in the near-surface layers of irradiated specimens. The observations of the irradiation-damaged microstructures in V-15Cr-5Ti specimens showed an absence of voids for irradiations of the alloy at 600-750 0 C to 200 dpa and at 725 0 C to 300 dpa. The principle effect on the microstructure of these irradiations was to induce the formation of a high density of disc-like precipitates in the vicinity of grain boundaries and intrinsic precipitates and on the dislocation structure. 8 references, 4 figures

Nuclear irradiation parameters of beryllium under fusion, fission and IFMIF irradiation conditions

International Nuclear Information System (INIS)

Fischer, U.; Chen, Y.; Leichtle, D.; Simakov, S.; Moeslang, A.; Vladimirov, P.

2004-01-01

A computational analysis is presented of the nuclear irradiation parameters for Beryllium under irradiation in typical neutron environments of fission and fusion reactors, and of the presently designed intense fusion neutron source IFMIF. The analysis shows that dpa and Tritium production rates at fusion relevant levels can be achieved with existing high flux fission reactors while the achievable Helium production is too low. The resulting He-Tritium and He/dpa ratios do not meet typical fusion irradiation conditions. Irradiation simulations in the medium flux test modules of the IFMIF neutron source facility were shown to be more suitable to match fusion typical irradiation conditions. To achieve sufficiently high production rates it is suggested to remove the creep-fatigue testing machine together with the W spectra shifter plate and move the tritium release module upstream towards the high flux test module. (author)

Recovering method for high level radioactive material

International Nuclear Information System (INIS)

Fukui, Toshiki

1998-01-01

Offgas filters such as of nuclear fuel reprocessing facilities and waste control facilities are burnt, and the burnt ash is melted by heating, and then the molten ashes are brought into contact with a molten metal having a low boiling point to transfer the high level radioactive materials in the molten ash to the molten metal. Then, only the molten metal is evaporated and solidified by drying, and residual high level radioactive materials are recovered. According to this method, the high level radioactive materials in the molten ashes are transferred to the molten metal and separated by the difference of the distribution rate of the molten ash and the molten metal. Subsequently, the molten metal to which the high level radioactive materials are transferred is heated to a temperature higher than the boiling point so that only the molten metal is evaporated and dried to be removed, and residual high level radioactive materials are recovered easily. On the other hand, the molten ash from which the high level radioactive material is removed can be discarded as ordinary industrial wastes as they are. (T.M.)

High-level-waste immobilization

International Nuclear Information System (INIS)

Crandall, J.L.

1982-01-01

Analysis of risks, environmental effects, process feasibility, and costs for disposal of immobilized high-level wastes in geologic repositories indicates that the disposal system safety has a low sensitivity to the choice of the waste disposal form

Aging and Embrittlement of High Fluence Stainless Steels

Energy Technology Data Exchange (ETDEWEB)

Was, gary; Jiao, Zhijie; der ven, Anton Van; Bruemmer, Stephen; Edwards, Dan

2012-12-31

Irradiation of austenitic stainless steels results in the formation of dislocation loops, stacking fault tetrahedral, Ni-Si clusters and radiation-induced segregation (RIS). Of these features, it is the formation of precipitates which is most likely to impact the mechanical integrity at high dose. Unlike dislocation loops and RIS, precipitates exhibit an incubation period that can extend from 10 to 46 dpa, above which the cluster composition changes and a separate phase, (G-phase) forms. Both neutron and heavy ion irradiation showed that these clusters develop slowly and continue to evolve beyond 100 dpa. Overall, this work shows that the irradiated microstructure features produced by heavy ion irradiation are remarkably comparable in nature to those produced by neutron irradiation at much lower dose rates. The use of a temperature shift to account for the higher damage rate in heavy ion irradiation results in a fairly good match in the dislocation loop microstructure and the precipitate microstructure in austenitic stainless steels. Both irradiations also show segregation of the same elements and in the same directions, but to achieve comparable magnitudes, heavy ion irradiation must be conducted at a much higher temperature than that which produces a match with loops and precipitates. First-principles modeling has confirmed that the formation of Ni-Si precipitates under irradiation is likely caused by supersaturation of solute to defect sinks caused by highly correlated diffusion of Ni and Si. Thus, the formation and evolution of Ni-Si precipitates at high dose in austenitic stainless steels containing Si is inevitable.

Microstructural evolution of HFIR-irradiated low activation F82H and F82H-10B steels

International Nuclear Information System (INIS)

Wakai, E.; Shiba, K.; Sawai, T.; Hashimoto, N.; Robertson, J.P.; Klueh, R.L.

1998-01-01

Microstructures of reduced-activation F82H (8Cr-2W-0.2V-0.04Ta) and the F82H steels doped with 10 B, irradiated at 250 and 300 C to 3 and 57 dpa in the High Flux Isotope Reactor (HFIR), were examined by TEM. In the F82H irradiated at 250 C to 3 dpa, dislocation loops, small unidentified defect clusters with a high number density, and a few MC precipitates were observed in the matrix. The defect microstructure after 300 C irradiation to 57 dpa is dominated by the loops, and the number density of loops was lower than that of the F82H- 10 B steel. Cavities were observed in the F82H- 10 B steels, but the swelling value is insignificant. Small particles of M 6 C formed on the M 23 C 6 carbides that were present in both steels before the irradiation at 300 C to 57 dpa. A low number density of MC precipitate particles formed in the matrix during irradiation at 300 C to 57 dpa

A High-Voltage Level Tolerant Transistor Circuit

NARCIS (Netherlands)

Annema, Anne J.; Geelen, Godefridus Johannes Gertrudis Maria

2001-01-01

A high-voltage level tolerant transistor circuit, comprising a plurality of cascoded transistors, including a first transistor (T1) operatively connected to a high-voltage level node (3) and a second transistor (T2) operatively connected to a low-voltage level node (2). The first transistor (T1)

Changes to the school food and physical activity environment after guideline implementation in British Columbia, Canada

OpenAIRE

Watts, Allison W; Mâsse, Louise C; Naylor, Patti-Jean

2014-01-01

Background High rates of childhood obesity have generated interest among policy makers to improve the school food environment and increase students’ levels of physical activity. The purpose of this study was to examine school-level changes associated with implementation of the Food and Beverage Sales in Schools (FBSS) and Daily Physical Activity (DPA) guidelines in British Columbia, Canada. Methods Elementary and middle/high school principals completed a survey on the school food and physical...

Enantiopure Chiral Coordination Polymers Based on Polynuclear Paddlewheel Helices and Arsenyl Tartrate

Directory of Open Access Journals (Sweden)

Ángela Valentín-Pérez

2018-03-01

Full Text Available Herein, we report the preparation of chiral, one-dimensional coordination polymers based on trinuclear paddlewheel helices [M3(dpa4]2+ (M = Co(II and Ni(II; dpa = the anion of 2,2′-dipyridylamine. Enantiomeric resolution of a racemic mixture of [M3(dpa4]2+ complexes was achieved by chiral recognition of the respective enantiomer by [Δ-As2(tartrate2]2− or [Λ-As2(tartrate2]2− in N,N-dimethylformamide (DMF, affording crystalline coordination polymers formed from [(Δ-Co3(dpa4(Λ-As2(tartrate2]·3DMF (Δ-1, [(Λ-Co3(dpa4(Δ-As2(tartrate2]·3DMF (Λ-1, [(Δ-Ni3(dpa4(Λ-As2(tartrate2]·(4 − nDMF∙nEt2O (Δ-2 or [(Λ-Ni3(dpa4(Δ-As2(tartrate2]·(4 − nDMF∙nEt2O (Λ-2 repeating units. UV-visible circular dichroism spectra of the complexes in DMF solutions demonstrate the efficient isolation of optically active species. The helicoidal [M3(dpa4]2+ units that were obtained display high stability towards racemization as shown by the absence of an evolution of the dichroic signals after several days at room temperature and only a small decrease of the signal after 3 h at 80 °C.

Low breast milk levels of long-chain n-3 fatty acids in allergic women, despite frequent fish intake.

Science.gov (United States)

Johansson, S; Wold, A E; Sandberg, A-S

2011-04-01

Long-chain n-3 polyunsaturated fatty acids (PUFAs) have immune regulating and anti-inflammatory effects. However, their role in allergic disease is unclear. Allergic diseases are immunologically heterogeneous, and we hypothesized that n-3 fatty acid composition in serum and breast milk may vary according to clinical manifestations. Further, animal studies have shown reduction of serum-PUFA levels during allergic inflammation. To investigate fatty acid composition in breast milk and serum from women with different atopic disease manifestations. Secondly, to determine whether low PUFA levels reflected insufficient intakes. Fatty acids were analysed in breast milk and serum of women with atopic eczema and respiratory allergy (n=16), only respiratory allergy (n=7), as well as healthy women (n=22). Dietary intake of foods expected to affect long-chain n-3 PUFA levels were estimated by food-frequency questionnaire. The fatty acid pattern was related to diagnostic group and intake of relevant food items using a multivariate pattern recognition method (partial least squares projections to latent structures and discriminant analysis). Results Women with a combination of eczema and respiratory allergy had lower breast milk levels of several PUFAs (arachidonic acid, eicosapentaenoic acid, EPA, docosahexaenoic acid, DHA, and docosapentaenoic acid, DPA), and a lower ratio of long-chain n-3 PUFAs/n-6 PUFAs. Their PUFA levels differed not only from that of healthy women, but also from that of women with only respiratory allergy. The latter had a fatty acid pattern similar to that of healthy women. Despite low EPA, DHA and DPA levels women with eczema and respiratory allergy consumed no less fish than did healthy women. Our data suggest that reduced levels of long-chain n-3 fatty acids in serum and breast milk characterize women with extensive allergic disease including eczema, and are not related to low fish intake. Consumption of PUFAs during the allergic process may explain

High-level waste processing and disposal

International Nuclear Information System (INIS)

Crandall, J.L.; Krause, H.; Sombret, C.; Uematsu, K.

1984-01-01

The national high-level waste disposal plans for France, the Federal Republic of Germany, Japan, and the United States are covered. Three conclusions are reached. The first conclusion is that an excellent technology already exists for high-level waste disposal. With appropriate packaging, spent fuel seems to be an acceptable waste form. Borosilicate glass reprocessing waste forms are well understood, in production in France, and scheduled for production in the next few years in a number of other countries. For final disposal, a number of candidate geological repository sites have been identified and several demonstration sites opened. The second conclusion is that adequate financing and a legal basis for waste disposal are in place in most countries. Costs of high-level waste disposal will probably add about 5 to 10% to the costs of nuclear electric power. The third conclusion is less optimistic. Political problems remain formidable in highly conservative regulations, in qualifying a final disposal site, and in securing acceptable transport routes

High levels of Porphyromonas gingivalis-induced immunoglobulin G2 are associated with lower high-density lipoprotein levels in chronic periodontitis.

Science.gov (United States)

Ardila, Carlos M; Guzmán, Isabel C

2016-11-01

To investigate the association between the presence of Porphyromonas gingivalis-induced immunoglobulin G antibodies and the high-density lipoprotein (HDL) level. A total of 108 individuals were examined. The presence of P. gingivalis was detected using primers designed to target the 16S rRNA gene sequence. Peripheral blood was collected from each subject to determine the levels of P. gingivalis-induced IgG1 and IgG2 serum antibodies. The HDL levels were determined using fully enzymatic methods. A higher proportion of periodontitis patients had high levels of P. gingivalis-induced IgG1 and IgG2, and the proportion of subjects with a HDL level of chronic periodontitis patients. In the unadjusted regression model, the presence of high levels of P. gingivalis-induced IgG2 was associated with a HDL level of periodontitis patients with high levels of P. gingivalis-induced IgG2 showed 3.2 more chances of having pathological HDL levels (odds ratio = 3.2, 95% confidence interval = 1.2-9.8). High levels of P. gingivalis-induced IgG2 were associated with low HDL concentrations in patients with periodontitis, which suggests that the response of the host to periodontal infection may play an important role in the pathogenesis of cardiovascular diseases. © 2015 Wiley Publishing Asia Pty Ltd.

Fracture mechanics behaviour of neutron irradiated Alloy A-286

International Nuclear Information System (INIS)

Mills, W.J.; James, L.A.

The effect of fast-neutron irradiation on the fatigue-crack propagation and fracture toughness behaviour of Alloy A-286 was characterized using fracture mechanics techniques. The fracture toughness was found to decrease continuously with increasing irradiation damage at both 24 deg. C and 427 deg. C. In the unirradiated and low fluence conditions, specimens displayed appreciable plasticity prior to fracture, and equivalent Ksub(Ic) values were determined from Jsub(Ic) fracture toughness results. At high irradiation exposure levels, specimens exhibited a brittle Ksub(Ic) fracture mode. The 427 deg. C fracture toughness fell from 129 MPa√m in the unirradiated condition to 35 MPa√m at an exposure of 16.2 dpa (total fluence of 5.2x10 22 n/cm 2 ). Room temperature fracture toughness values were consistently 40 to 60 percent higher than the 427 deg. C values. Electron fractography revealed that the reduction in fracture resistance was attributed to a fracture mechanism transition from ductile microvoid coalescence to channel fracture. Fatigue-crack propagation tests were conducted at 427 deg. C on specimens irradiated at 2.4 dpa and 16.2 dpa. Crack growth rates at the lower exposure level were comparable to those in unirradiated material, while those at the higher exposure were slightly higher than in unirradiated material. (author)

Radiation-induced grain boundary segregation in austenitic stainless steels

International Nuclear Information System (INIS)

Bruemmer, S.M.; Charlot, L.A.; Vetrano, J.S.; Simonen, E.P.

1994-11-01

Radiation-induced segregation (RIS) to grain boundaries in Fe-Ni-Cr-Si stainless alloys has been measured as a function of irradiation temperature and dose. Heavy-ion irradiation was used to produce damage levels from 1 to 20 displacements per atom (dpa) at temperatures from 175 to 550 degrees C. Measured Fe, Ni, and Cr segregation increased sharply with irradiation dose (from G to 5 dpa) and temperature (from 175 to about 350 degrees C). However, grain boundary concentrations did not change significantly as dose or temperatures were further increased. Although interfacial compositions were similar, the width of radiation-induced enrichment or depletion profiles increased consistently with increasing dose or temperature. Impurity segregation (Si and P) was also measured, but only Si enrichment appeared to be radiation-induced. Grain boundary Si peaked at levels approaching 10 at% after irradiation doses to 10 dpa at an intermediate temperature of 325 degrees C. No evidence of grain boundary silicide precipitation was detected after irradiation at any temperature. Equilibrium segregation of P was measured in the high-P alloys, but interfacial concentration did not increase with irradiation exposure. Comparisons to reported RIS in neutron-irradiated stainless steels revealed similar grain boundary compositional changes for both major alloying and impurity elements

High-Level Application Framework for LCLS

Energy Technology Data Exchange (ETDEWEB)

Chu, P; Chevtsov, S.; Fairley, D.; Larrieu, C.; Rock, J.; Rogind, D.; White, G.; Zalazny, M.; /SLAC

2008-04-22

A framework for high level accelerator application software is being developed for the Linac Coherent Light Source (LCLS). The framework is based on plug-in technology developed by an open source project, Eclipse. Many existing functionalities provided by Eclipse are available to high-level applications written within this framework. The framework also contains static data storage configuration and dynamic data connectivity. Because the framework is Eclipse-based, it is highly compatible with any other Eclipse plug-ins. The entire infrastructure of the software framework will be presented. Planned applications and plug-ins based on the framework are also presented.

The transcriptome of the developing grain: a resource for understanding seed development and the molecular control of the functional and nutritional properties of wheat.

Science.gov (United States)

Rangan, Parimalan; Furtado, Agnelo; Henry, Robert J

2017-10-11

Wheat is one of the three major cereals that have been domesticated to feed human populations. The composition of the wheat grain determines the functional properties of wheat including milling efficiency, bread making, and nutritional value. Transcriptome analysis of the developing wheat grain provides key insights into the molecular basis for grain development and quality. The transcriptome of 35 genotypes was analysed by RNA-Seq at two development stages (14 and 30 days-post-anthesis, dpa) corresponding to the mid stage of development (stage Z75) and the almost mature seed (stage Z85). At 14dpa, most of the transcripts were associated with the synthesis of the major seed components including storage proteins and starch. At 30dpa, a diverse range of genes were expressed at low levels with a predominance of genes associated with seed defence and stress tolerance. RNA-Seq analysis of changes in expression between 14dpa and 30dpa stages revealed 26,477 transcripts that were significantly differentially expressed at a FDR corrected p-value cut-off at ≤0.01. Functional annotation and gene ontology mapping was performed and KEGG pathway mapping allowed grouping based upon biochemical linkages. This analysis demonstrated that photosynthesis associated with the pericarp was very active at 14dpa but had ceased by 30dpa. Recently reported genes for flour yield in milling and bread quality were found to influence wheat quality largely due to expression patterns at the earlier seed development stage. This study serves as a resource providing an overview of gene expression during wheat grain development at the early (14dpa) and late (30dpa) grain filling stages for use in studies of grain quality and nutritional value and in understanding seed biology.

Chemical functionalization of crystalline silicon surface with complexes of type (M3 (Dpa) 4X2) for the development of electronic devices

International Nuclear Information System (INIS)

Sanchez Zamora, Maria Alejandra

2012-01-01

New surfaces on crystalline silicon (100) diamines have been developed. The diamines 4-aminopyridine, 4-aminomethylpyridine and 1,12-dodecildiame, and self-assembled surfaces Si-diamine-metallic complexes, with cooper (II) acetate and trimetal Cu 3 (dpa) 4 CI 2 were studied. These surfaces are characterized with X-ray photoelectron spectroscopy (XPS), chemical force microscopy (CFM), by contact angle and cyclic voltammetry (CV). The XPS has suggested the formation of diamines monolayers with covalent binding to crystalline silicon, and modification of these surfaces, with metal complexes by coordination chemistry. The CFM has confirmed that surfaces are modified with diamines and cooper (II) acetate, and that were determined different chemical forces according to the change. The contact angle has been suggested that the functionalized surface with 4-aminomethylpyridine has had similar basicity to 1,12-dodecildiame, and more than 4-aminopyridine. This implies that the coordination with metallics complexes is benefited with 4-aminopyridine, which in turn is reflected with electrochemical data. Cyclic voltammetry analysis have showed that silicon surfaces with 4-aminomethylpyridine and 4-aminopyridine with cooper (II) acetate and trimetal have been electrochemically active. Thus, the surfaces could to have interesting applications in molecular electronics. (author) [es

Exploring the association between whole blood Omega-3 Index, DHA, EPA, DHA, AA and n-6 DPA, and depression and self-esteem in adolescents of lower general secondary education.

Science.gov (United States)

van der Wurff, I S M; von Schacky, C; Bergeland, T; Leontjevas, R; Zeegers, M P; Kirschner, P A; de Groot, R H M

2018-03-16

Depression is common in adolescents and long-chain polyunsaturated fatty acids (LCPUFA) are suggested to be associated with depression. However, research in adolescents is limited. Furthermore, self-esteem has never been studied in relation to LCPUFA. The objective here was to determine associations of depression and self-esteem with eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), Omega-3 Index (O3I), n-6 docosapentaenoic acid (n-6 DPA, also called Osbond acid, ObA), n-3 docosapentaenoic acid (DPA), and arachidonic acid (AA) concentrations in blood of adolescents attending lower general secondary education (LGSE). Baseline cross-sectional data from a krill oil supplementation trial in adolescents attending LGSE with an O3I ≤ 5% were analysed using regression models built with the BayesFactor package in R. Fatty acids and O3I were determined in blood. Participants filled out the Centre for Epidemiologic Studies Depression (CES-D) scale and the Rosenberg Self-Esteem scale (RSE). Scores indicative of depression (CES-D ≥ 16) were found in 29.4% of the respondents. Of all fatty acids, we found extreme evidence [Bayes factor (BF) > 100] for a weak negative association between ObA and depression score [- 0.16; 95% credible interval (CI) - 0.28 to - 0.04; BF 10  = 245], and substantial evidence for a weak positive association between ObA and self-esteem score (0.09; 95% CI, - 0.03 to 0.20; BF 10  = 4). When all fatty acids were put in one model as predictors of CES-D or RSE, all of the 95% CI contained 0, i.e., no significant association. No evidence was found for associations of DHA, EPA and O3I with depression or self-esteem scores in LGSE adolescents with O3I ≤ 5%. The associations of higher ObA status with lower depression and higher self-esteem scores warrant more research.

General Algorithm (High level)

Indian Academy of Sciences (India)

First page Back Continue Last page Overview Graphics. General Algorithm (High level). Iteratively. Use Tightness Property to remove points of P1,..,Pi. Use random sampling to get a Random Sample (of enough points) from the next largest cluster, Pi+1. Use the Random Sampling Procedure to approximate ci+1 using the ...

Development and validation status of the IFMIF High Flux Test Module

International Nuclear Information System (INIS)

Arbeiter, Frederik; Abou-Sena, Ali; Chen Yuming; Dolensky, Bernhard; Heupel, Tobias; Klein, Christine; Scheel, Nicola; Schlindwein, Georg

2011-01-01

The development of the IFMIF (International Fusion Material Irradiation Facility) High Flux Test Module in the EVEDA (Engineering Validation and Engineering Design Activities) phase up to 2013 includes conceptual design, engineering analyses, as well as design and engineering validation by building of prototypes and their testing. The High Flux Test Module is the device to facilitate the irradiation of SSTT samples of RAFM steels at temperatures 250-550 deg. C and up to an accumulated irradiation damage of 150 dpa. The requirements, the current design and the performance of the module are discussed, and the development process is outlined.

Development and validation status of the IFMIF High Flux Test Module

Energy Technology Data Exchange (ETDEWEB)

Arbeiter, Frederik, E-mail: frederik.arbeiter@kit.edu [Karlsruhe Institute of Technology, Institute for Neutron Physics and Reactor Technology (KIT-INR), Karlsruhe (Germany); Abou-Sena, Ali; Chen Yuming; Dolensky, Bernhard; Heupel, Tobias; Klein, Christine; Scheel, Nicola; Schlindwein, Georg [Karlsruhe Institute of Technology, Institute for Neutron Physics and Reactor Technology (KIT-INR), Karlsruhe (Germany)

2011-10-15

The development of the IFMIF (International Fusion Material Irradiation Facility) High Flux Test Module in the EVEDA (Engineering Validation and Engineering Design Activities) phase up to 2013 includes conceptual design, engineering analyses, as well as design and engineering validation by building of prototypes and their testing. The High Flux Test Module is the device to facilitate the irradiation of SSTT samples of RAFM steels at temperatures 250-550 deg. C and up to an accumulated irradiation damage of 150 dpa. The requirements, the current design and the performance of the module are discussed, and the development process is outlined.

A Decade-Bandwidth Distributed Power Amplifier MMIC Using 0.25 μm GaN HEMT Technology

Directory of Open Access Journals (Sweden)

Dong-Hwan Shin

2017-10-01

Full Text Available This study presents a 2–20 GHz monolithic distributed power amplifier (DPA using a 0.25 μm AlGaN/GaN on SiC high electron mobility transistor (HEMT technology. The gate width of the HEMT was selected after considering the input capacitance of the unit cell that guarantees decade bandwidth. To achieve high output power using small transistors, a 12-stage DPA was designed with a nonuniform drain line impedance to provide optimal output power matching. The maximum operating frequency of the proposed DPA is above 20 GHz, which is higher than those of other DPAs manufactured with the same gate-length process. The measured output power and power-added efficiency of the DPA monolithic microwave integrated circuit (MMIC are 35.3–38.6 dBm and 11.4%–31%, respectively, for 2–20 GHz.

Metabolomic Characterization of Hot Pepper (Capsicum annuum "CM334") during Fruit Development.

Science.gov (United States)

Jang, Yu Kyung; Jung, Eun Sung; Lee, Hyun-Ah; Choi, Doil; Lee, Choong Hwan

2015-11-04

Non-targeted metabolomic analysis of hot pepper (Capsicum annuum "CM334") was performed at six development stages [16, 25, 36, 38, 43, and 48 days post-anthesis (DPA)] to analyze biochemical changes. Distinct distribution patterns were observed in the changes of metabolites, gene expressions, and antioxidant activities by early (16-25 DPA), breaker (36-38 DPA), and later (43-48 DPA) stages. In the early stages, glycosides of luteolin, apigenin, and quercetin, shikimic acid, γ-aminobutyric acid (GABA), and putrescine were highly distributed but gradually decreased over the breaker stage. At later stages, leucine, isoleucine, proline, phenylalanine, capsaicin, dihydrocapsaicin, and kaempferol glycosides were significantly increased. Pathway analysis revealed metabolite-gene interactions in the biosynthesis of amino acids, capsaicinoids, fatty acid chains, and flavonoids. The changes in antioxidant activity were highly reflective of alterations in metabolites. The present study could provide useful information about nutrient content at each stage of pepper cultivation.

Partitioning of high level liquid waste: experiences in plant level adoption

International Nuclear Information System (INIS)

Manohar, Smitha; Kaushik, C.P.

2016-01-01

High Level Radioactive Wastes are presently vitrified in borosilicate matrices in all our back end facilities in our country. This is in accordance with internationally endorsed methodology for the safe management of high level radioactive wastes. Recent advancements in the field of partitioning technology in our group, has presented us with an opportunity to have a fresh perspective on management of high level liquid radioactive wastes streams, that emanate from reprocessing operations. This paper will highlight our experiences with respect to both partitioning studies and vitrification practices, with a focus on waste volume reduction for final disposal. Incorporation of this technique has led to the implementation of the concept of recovering wealth from waste, a marked decrease on the load of disposal in deep geological repositories and serve as a step towards the vision of transmutation of long lived radionuclides

Irradiation-induced stress relaxation of Eurofer97 steel

International Nuclear Information System (INIS)

Luzginova, N.V.; Jong, M.; Rensman, J.W.; Hegeman, J.B.J.; Laan, J.G. van der

2011-01-01

The irradiation-induced stress relaxation behavior of Eurofer97 at 300 deg. C up to 3.4 dpa and under pre-stress loads typical for the ITER applications is investigated. The bolt specimens are pre-loaded from 30% to 90% of the yield strength. To verify the results obtained with the pre-stressed bolts, bent strips were investigated as well. The strips are bent into a pre-defined radius in order to achieve similar pre-stress levels. The irradiation-induced stress relaxation is found to be independent of the pre-stress level. 10-12% of the stress relaxation in Eurofer97 may be reached after a dose of 0.1 dpa, and after an irradiation dose of 2.7 dpa 42-47% of the original pre-stress is retained.

Predictors of Placement in Lower Level versus Higher Level High School Mathematics

Science.gov (United States)

Archbald, Doug; Farley-Ripple, Elizabeth N.

2012-01-01

Educators and researchers have long been interested in determinants of access to honors level and college prep courses in high school. Factors influencing access to upper level mathematics courses are particularly important because of the hierarchical and sequential nature of this subject and because students who finish high school with only lower…

High-Level Development of Multiserver Online Games

Directory of Open Access Journals (Sweden)

Frank Glinka

2008-01-01

Full Text Available Multiplayer online games with support for high user numbers must provide mechanisms to support an increasing amount of players by using additional resources. This paper provides a comprehensive analysis of the practically proven multiserver distribution mechanisms, zoning, instancing, and replication, and the tasks for the game developer implied by them. We propose a novel, high-level development approach which integrates the three distribution mechanisms seamlessly in today's online games. As a possible base for this high-level approach, we describe the real-time framework (RTF middleware system which liberates the developer from low-level tasks and allows him to stay at high level of design abstraction. We explain how RTF supports the implementation of single-server online games and how RTF allows to incorporate the three multiserver distribution mechanisms during the development process. Finally, we describe briefly how RTF provides manageability and maintenance functionality for online games in a grid context with dynamic resource allocation scenarios.

Long-term high-level waste technology program

International Nuclear Information System (INIS)

1980-04-01

The Department of Energy (DOE) is conducting a comprehensive program to isolate all US nuclear wastes from the human environment. The DOE Office of Nuclear Energy - Waste (NEW) has full responsibility for managing the high-level wastes resulting from defense activities and additional responsiblity for providing the technology to manage existing commercial high-level wastes and any that may be generated in one of several alternative fuel cycles. Responsibilities of the Three Divisions of DOE-NEW are shown. This strategy document presents the research and development plan of the Division of Waste Products for long-term immobilization of the high-level radioactive wastes resulting from chemical processing of nuclear reactor fuels and targets. These high-level wastes contain more than 99% of the residual radionuclides produced in the fuels and targets during reactor operations. They include essentially all the fission products and most of the actinides that were not recovered for use

High-Level Radioactive Waste.

Science.gov (United States)

Hayden, Howard C.

1995-01-01

Presents a method to calculate the amount of high-level radioactive waste by taking into consideration the following factors: the fission process that yields the waste, identification of the waste, the energy required to run a 1-GWe plant for one year, and the uranium mass required to produce that energy. Briefly discusses waste disposal and…

High-level radioactive wastes

International Nuclear Information System (INIS)

Grissom, M.C.

1982-10-01

This bibliography contains 812 citations on high-level radioactive wastes included in the Department of Energy's Energy Data Base from January 1981 through July 1982. These citations are to research reports, journal articles, books, patents, theses, and conference papers from worldwide sources. Five indexes are provided: Corporate Author, Personal Author, Subject, Contract Number, and Report Number

Process for solidifying high-level nuclear waste

Science.gov (United States)

Ross, Wayne A.

1978-01-01

The addition of a small amount of reducing agent to a mixture of a high-level radioactive waste calcine and glass frit before the mixture is melted will produce a more homogeneous glass which is leach-resistant and suitable for long-term storage of high-level radioactive waste products.

Characteristics of solidified high-level waste products

International Nuclear Information System (INIS)

1979-01-01

The object of the report is to contribute to the establishment of a data bank for future preparation of codes of practice and standards for the management of high-level wastes. The work currently in progress on measuring the properties of solidified high-level wastes is being studied

High-level waste immobilization program: an overview

International Nuclear Information System (INIS)

Bonner, W.R.

1979-09-01

The High-Level Waste Immobilization Program is providing technology to allow safe, affordable immobilization and disposal of nuclear waste. Waste forms and processes are being developed on a schedule consistent with national needs for immobilization of high-level wastes stored at Savannah River, Hanford, Idaho National Engineering Laboratory, and West Valley, New York. This technology is directly applicable to high-level wastes from potential reprocessing of spent nuclear fuel. The program is removing one more obstacle previously seen as a potential restriction on the use and further development of nuclear power, and is thus meeting a critical technological need within the national objective of energy independence

National high-level waste systems analysis report

Energy Technology Data Exchange (ETDEWEB)

Kristofferson, K.; Oholleran, T.P.; Powell, R.H.

1995-09-01

This report documents the assessment of budgetary impacts, constraints, and repository availability on the storage and treatment of high-level waste and on both existing and pending negotiated milestones. The impacts of the availabilities of various treatment systems on schedule and throughput at four Department of Energy sites are compared to repository readiness in order to determine the prudent application of resources. The information modeled for each of these sites is integrated with a single national model. The report suggests a high-level-waste model that offers a national perspective on all high-level waste treatment and storage systems managed by the Department of Energy.

National high-level waste systems analysis report

International Nuclear Information System (INIS)

Kristofferson, K.; Oholleran, T.P.; Powell, R.H.

1995-09-01

This report documents the assessment of budgetary impacts, constraints, and repository availability on the storage and treatment of high-level waste and on both existing and pending negotiated milestones. The impacts of the availabilities of various treatment systems on schedule and throughput at four Department of Energy sites are compared to repository readiness in order to determine the prudent application of resources. The information modeled for each of these sites is integrated with a single national model. The report suggests a high-level-waste model that offers a national perspective on all high-level waste treatment and storage systems managed by the Department of Energy

Overview: Defense high-level waste technology program

International Nuclear Information System (INIS)

Shupe, M.W.; Turner, D.A.

1987-01-01

Defense high-level waste generated by atomic energy defense activities is stored on an interim basis at three U.S. Department of Energy (DOE) operating locations; the Savannah River Plant in South Carolina, the Hanford Site in Washington, and the Idaho National Engineering Laboratory in Idaho. Responsibility for the permanent disposal of this waste resides with DOE's Office of Defense Waste and Transportation Management. The objective of the Defense High-Level Wast Technology Program is to develop the technology for ending interim storage and achieving permanent disposal of all U.S. defense high-level waste. New and readily retrievable high-level waste are immobilized for disposal in a geologic repository. Other high-level waste will be stabilized in-place if, after completion of the National Environmental Policy Act (NEPA) process, it is determined, on a site-specific basis, that this option is safe, cost effective and environmentally sound. The immediate program focus is on implementing the waste disposal strategy selected in compliance with the NEPA process at Savannah River, while continuing progress toward development of final waste disposal strategies at Hanford and Idaho. This paper presents an overview of the technology development program which supports these waste management activities and an assessment of the impact that recent and anticipated legal and institutional developments are expected to have on the program

Disposal of high-level radioactive waste

International Nuclear Information System (INIS)

Glasby, G.P.

1977-01-01

Although controversy surrounding the possible introduction of nuclear power into New Zealand has raised many points including radiation hazards, reactor safety, capital costs, sources of uranium and earthquake risks on the one hand versus energy conservation and alternative sources of energy on the other, one problem remains paramount and is of global significance - the storage and dumping of the high-level radioactive wastes of the reactor core. The generation of abundant supplies of energy now in return for the storage of these long-lived highly radioactive wastes has been dubbed the so-called Faustian bargain. This article discusses the growth of the nuclear industry and its implications to high-level waste disposal particularly in the deep-sea bed. (auth.)

40 CFR 227.30 - High-level radioactive waste.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 24 2010-07-01 2010-07-01 false High-level radioactive waste. 227.30...-level radioactive waste. High-level radioactive waste means the aqueous waste resulting from the operation of the first cycle solvent extraction system, or equivalent, and the concentrated waste from...

Estimation of irradiation-induced material damage measure of FCM fuel in LWR core

International Nuclear Information System (INIS)

Lee, Kyung-Hoon; Lee, Chungchan; Park, Sang-Yoon; Cho, Jin-Young; Chang, Jonghwa; Lee, Won Jae

2014-01-01

An irradiation-induced material damage measure on tri-isotropic (TRISO) multi-coating layers of fully ceramic micro-encapsulated (FCM) fuel to replace conventional uranium dioxide (UO 2 ) fuel for existing light water reactors (LWRs) has been estimated using a displacement per atom (DPA) cross section for a FCM fuel performance analysis. The DPA cross sections in 47 and 190 energy groups for both silicon carbide (SiC) and graphite are generated based on the molecular dynamics simulation by SRIM/TRIM. For the selected FCM fuel assembly design with FeCrAl cladding, a core depletion analysis was carried out using the DeCART2D/MASTER code system with the prepared DPA cross sections to evaluate the irradiation effect in the Korean OPR-1000. The DPA of the SiC and IPyC coating layers is estimated by comparing the discharge burnup obtained from the MASTER calculation with the burnup-dependent DPA for each coating layer calculated using DeCART2D. The results show that low uranium loading and hardened neutron spectrum compared to that of high temperature gas-cooled reactor (HTGR) result in high discharge burnup and high fast neutron fluence. In conclusion, it can be seen that the irradiation-induced material damage measure is noticeably increased under LWR operating conditions compared to HTGRs. (author)

Overview of the IFMIF test cell design

International Nuclear Information System (INIS)

Moeslang, A.; Daum, E.; Jitsukawa, S.; Noda, K.; Viola, R.

1996-01-01

The Conceptual Design Activity (CDA) for the International Fusion Materials Irradiation Facility (IFMIF) has entered its second and final year, and an outline design has been developed. Initial evaluations of the potential of this high flux, high intensity D-Li source have shown that the main materials testing needs can be fulfilled. According to these needs, Vertical Test Assemblies will accommodate test modules for the high flux (0.5 liter, 20 dpa/a, 250-1000 C), the medium flux (6 liter, 1-20 dpa/a, 250-1000 C), the low flux (7.5 liter, 0.1-1 dpa/a), and the very low flux (> 100 liter, 0.01-0.1 dpa/a) regions. Detailed test matrices have been defined for the high and medium flux regions, showing that on the basis of small specimen test technologies, a database for an engineering design of an advanced fusion reactor (DEMO) can be established for a variety of structural materials and ceramic breeders. The design concepts for the Test Cell, including test assemblies, remote handling equipment and Hot Cell Facilities with capacity for investigating all irradiation specimens at the IFMIF site are described

Nuclear medical methods for determination of bone mineral content

International Nuclear Information System (INIS)

Fischer, M.; Kempers, B.; Tschepke, H.D.; Spitz, J.

1988-01-01

Osteoporosis is becoming recognized as a major social and economical health problem. Bone mineral content (BMC) depends on many hormonal and metabolic factors. The pathophysiological mechanism of the loss of bone mass is still unclear. For preventive diagnosis and treatment of osteoporosis, quantitative technology is required that will measure BMC with high precision and reproducibility. Nuclear medical methods permit the BMC of the appendicular skeleton to be measured by single photon absorptiometry. Whole-body BMC, as well as spine and femur BMC, can be measured by dual photon absorptiometry. The results from both procedures are reasonably precise and correlate well with the ash weight of isolated bone. The radiation exposure level in both SPA and DPA is low. SPA and DPA may be used for cost-effective screening of high-risk patients to predict the likelihood of future fractures and control osteoporosis therapy. (orig.) [de

Precipitate evolution in low-nickel austenitic stainless steels during neutron irradiation at very low dose rates

International Nuclear Information System (INIS)

Isobe, Y.; Sagisaka, M.; Garner, F.; Okita, T.

2007-01-01

Full text of publication follows: Not all components of a fusion reactor will be subjected to high atomic displacement rates. Some components outside the plasma containment may experience relatively low displacement rates but data generated under long-term irradiation at low dpa rates is hard to obtain. In another study the neutron-induced microstructural evolution in response to long term irradiation at very low dose rates was studied for a Russian low-nickel austenitic stainless steel that is analogous to AISI 304. The irradiated samples were obtained from an out-of-core anti-crush support column for the BN-600 fast reactor with doses ranging from 1.5 to 22 dpa generated at 3x10 -9 to 4x10 -8 dpa/s. The irradiation temperatures were in a very narrow range of 370-375 deg. C. Microstructural observation showed that in addition to voids and dislocations, an unexpectedly high density of small carbide precipitates was formed that are not usually observed at higher dpa rates in this temperature range. These results required us to ask if such unexpected precipitation was anomalous or was a general feature of low-flux, long-term irradiation. It is shown in this paper that a similar behavior was observed in a western stainless steel, namely AISI 304 stainless steel, irradiated at similar temperatures and dpa rates in the EBR-II fast reactor, indicating that irradiation at low dpa rates for many years leads to a different precipitate microstructure and therefore different associated changes in matrix composition than are generated at higher dpa rates. One consequence of this precipitation is a reduced lattice parameter of the alloy matrix, leading to densification that increases in strength with increasing temperature and dose. A. non-destructive method to evaluate these precipitates is under development and is also discussed in this paper. (authors)

Erbium:ytterbium fiber-laser system delivering watt-level femtosecond pulses using divided pulse amplification

Science.gov (United States)

Herda, Robert; Zach, Armin

2015-03-01

We present an Erbium:Ytterbium codoped fiber-amplifer system based on Divided-Pulses-Amplification (DPA) for ultrashort pulses. The output from a saturable-absorber mode-locked polarization-maintaining (PM) fiber oscillator is amplified in a PM normal-dispersion Erbium-doped fiber. After this stage the pulses are positively chirped and have a duration of 2.0 ps at an average power of 93 mW. A stack of 5 birefringent Yttrium-Vanadate crystals divides these pulses 32 times. We amplify these pulses using a double-clad Erbium:Ytterbium codoped fiber pumped through a multimode fiber combiner. The pulses double pass the amplifier and recombine in the crystals using non-reciprocal polarization 90° rotation by a Faraday rotating mirror. Pulses with a duration of 144 fs are obtained after separation from the input beam using a polarizing beam splitter cube. These pulses have an average power of 1.85 W at a repetition rate of 80 MHz. The generation of femtosecond pulses directly from the amplifier was enabled by a positively chirped seed pulse, normally dispersive Yttrium-Vanadate crystals, and anomalously dispersive amplifier fibers. Efficient frequency doubling to 780 nm with an average power of 725 mW and a pulse duration of 156 fs is demonstrated. In summary we show a DPA setup that enables the generation of femtosecond pulses at watt-level at 1560 nm without the need for further external dechirping and demonstrate a good pulse quality by efficient frequency doubling. Due to the use of PM fiber components and a Faraday rotator the setup is environmentally stable.

Handling and storage of conditioned high-level wastes

International Nuclear Information System (INIS)

1983-01-01

This report deals with certain aspects of the management of one of the most important wastes, i.e. the handling and storage of conditioned (immobilized and packaged) high-level waste from the reprocessing of spent nuclear fuel and, although much of the material presented here is based on information concerning high-level waste from reprocessing LWR fuel, the principles, as well as many of the details involved, are applicable to all fuel types. The report provides illustrative background material on the arising and characteristics of high-level wastes and, qualitatively, their requirements for conditioning. The report introduces the principles important in conditioned high-level waste storage and describes the types of equipment and facilities, used or studied, for handling and storage of such waste. Finally, it discusses the safety and economic aspects that are considered in the design and operation of handling and storage facilities

Handling and storage of conditioned high-level wastes

International Nuclear Information System (INIS)

Heafield, W.

1984-01-01

This paper deals with certain aspects of the management of one of the most important radioactive wastes arising from the nuclear fuel cycle, i.e. the handling and storage of conditioned high-level wastes. The paper is based on an IAEA report of the same title published during 1983 in the Technical Reports Series. The paper provides illustrative background material on the characteristics of high-level wastes and, qualitatively, their requirements for conditioning. The principles important in the storage of high-level wastes are reviewed in conjunction with the radiological and socio-political considerations involved. Four fundamentally different storage concepts are described with reference to published information and the safety aspects of particular storage concepts are discussed. Finally, overall conclusions are presented which confirm the availability of technology for constructing and operating conditioned high-level waste storage facilities for periods of at least several decades. (author)

In vitro response to EPA, DPA, and DHA: Comparison of effects on ruminal fermentation and biohydrogenation of 18-carbon fatty acids in cows and ewes.

Science.gov (United States)

Toral, P G; Hervás, G; Carreño, D; Leskinen, H; Belenguer, A; Shingfield, K J; Frutos, P

2017-08-01

The modulation of milk fat nutritional quality through fish oil supplementation seems to be largely explained by the action of n-3 very long chain polyunsaturated fatty acids (PUFA) on ruminal biohydrogenation (BH) of C18 fatty acids (FA). However, relationships among this action, disappearance of those PUFA in the rumen, and potential detrimental consequences on ruminal fermentation remain uncertain. This study compared the effect of 20:5n-3 (eicosapentaenoic acid; EPA), 22:5n-3 (docosapentaenoic acid; DPA), and 22:6n-3 (docosahexaenoic acid; DHA) on rumen fermentation and BH of C18 FA and was conducted simultaneously in cows and sheep to provide novel insights into interspecies differences. The trial was performed in vitro using batch cultures of rumen microorganisms with inocula collected from cannulated cows and ewes. The PUFA were added at a dose of 2% incubated dry matter, and treatment effects on ruminal C18 FA concentrations, PUFA disappearances, and fermentation parameters (gas production, ammonia and volatile FA concentrations, and dry matter and neutral detergent fiber disappearances) were examined after 24 h of incubation. A principal component analysis suggested that responses to PUFA treatments explained most of the variability; those of ruminant species were of lower relevance. Overall, EPA and DHA were equally effective for inhibiting the saturation of trans-11 18:1 to 18:0 and had a similar influence on ruminal fermentation in cows and sheep (e.g., reductions in gas production and acetate:propionate ratio). Nevertheless, DHA further promoted alternative BH pathways that lead to trans-10 18:1 accumulation, and EPA seemed to have specific effects on 18:3n-3 metabolism. Only minor variations attributable to DPA were observed in the studied parameters, suggesting a low contribution of this FA to the action of marine lipids. Although most changes due to the added PUFA were comparable in bovine and ovine, there were also relevant specificities, such as a

The ATLAS High-Level Calorimeter Trigger in Run-2

CERN Document Server

Wiglesworth, Craig; The ATLAS collaboration

2018-01-01

The ATLAS Experiment uses a two-level triggering system to identify and record collision events containing a wide variety of physics signatures. It reduces the event rate from the bunch-crossing rate of 40 MHz to an average recording rate of 1 kHz, whilst maintaining high efficiency for interesting collision events. It is composed of an initial hardware-based level-1 trigger followed by a software-based high-level trigger. A central component of the high-level trigger is the calorimeter trigger. This is responsible for processing data from the electromagnetic and hadronic calorimeters in order to identify electrons, photons, taus, jets and missing transverse energy. In this talk I will present the performance of the high-level calorimeter trigger in Run-2, noting the improvements that have been made in response to the challenges of operating at high luminosity.

Empirical relations for tensile properties of austenitic stainless steels irradiated in mixed-spectrum reactors

International Nuclear Information System (INIS)

Grossbeck, M.L.

1991-01-01

An assessment has been made of available tensile property data relevant to the design of fusion reactors, especially near term devices expected to operate at lower temperatures than power reactors. Empirical relations have been developed for the tensile properties as a functions of irradiation temperature for neutron exposures of 10-15, 20, 30, and 50 dpa. It was found that yield strength depends little on the particular austenitic alloy and little on the helium concentration. Strength depends upon initial condition of the alloy only for exposures of less than 30 dpa. Uniform elongation was found to be more sensitive to alloy and condition. It was also more sensitive than strength to helium level. However, below 500deg C, helium only appeared to have an efect at 10-15 dpa. At higher temperatures, helium embrittlement was apparent, and its threshold temperature decreased with increasing neutron exposure level. (orig.)

High-Level Waste System Process Interface Description

International Nuclear Information System (INIS)

D'Entremont, P.D.

1999-01-01

The High-Level Waste System is a set of six different processes interconnected by pipelines. These processes function as one large treatment plant that receives, stores, and treats high-level wastes from various generators at SRS and converts them into forms suitable for final disposal. The three major forms are borosilicate glass, which will be eventually disposed of in a Federal Repository, Saltstone to be buried on site, and treated water effluent that is released to the environment

High-Level Waste Vitrification Facility Feasibility Study

Energy Technology Data Exchange (ETDEWEB)

D. A. Lopez

1999-08-01

A ''Settlement Agreement'' between the Department of Energy and the State of Idaho mandates that all radioactive high-level waste now stored at the Idaho Nuclear Technology and Engineering Center will be treated so that it is ready to be moved out of Idaho for disposal by a compliance date of 2035. This report investigates vitrification treatment of the high-level waste in a High-Level Waste Vitrification Facility based on the assumption that no more New Waste Calcining Facility campaigns will be conducted after June 2000. Under this option, the sodium-bearing waste remaining in the Idaho Nuclear Technology and Engineering Center Tank Farm, and newly generated liquid waste produced between now and the start of 2013, will be processed using a different option, such as a Cesium Ion Exchange Facility. The cesium-saturated waste from this other option will be sent to the Calcine Solids Storage Facilities to be mixed with existing calcine. The calcine and cesium-saturated waste will be processed in the High-Level Waste Vitrification Facility by the end of calendar year 2035. In addition, the High-Level Waste Vitrification Facility will process all newly-generated liquid waste produced between 2013 and the end of 2035. Vitrification of this waste is an acceptable treatment method for complying with the Settlement Agreement. This method involves vitrifying the waste and pouring it into stainless-steel canisters that will be ready for shipment out of Idaho to a disposal facility by 2035. These canisters will be stored at the Idaho National Engineering and Environmental Laboratory until they are sent to a national geologic repository. The operating period for vitrification treatment will be from the end of 2015 through 2035.

High-Level Waste Vitrification Facility Feasibility Study

International Nuclear Information System (INIS)

D. A. Lopez

1999-01-01

A ''Settlement Agreement'' between the Department of Energy and the State of Idaho mandates that all radioactive high-level waste now stored at the Idaho Nuclear Technology and Engineering Center will be treated so that it is ready to be moved out of Idaho for disposal by a compliance date of 2035. This report investigates vitrification treatment of the high-level waste in a High-Level Waste Vitrification Facility based on the assumption that no more New Waste Calcining Facility campaigns will be conducted after June 2000. Under this option, the sodium-bearing waste remaining in the Idaho Nuclear Technology and Engineering Center Tank Farm, and newly generated liquid waste produced between now and the start of 2013, will be processed using a different option, such as a Cesium Ion Exchange Facility. The cesium-saturated waste from this other option will be sent to the Calcine Solids Storage Facilities to be mixed with existing calcine. The calcine and cesium-saturated waste will be processed in the High-Level Waste Vitrification Facility by the end of calendar year 2035. In addition, the High-Level Waste Vitrification Facility will process all newly-generated liquid waste produced between 2013 and the end of 2035. Vitrification of this waste is an acceptable treatment method for complying with the Settlement Agreement. This method involves vitrifying the waste and pouring it into stainless-steel canisters that will be ready for shipment out of Idaho to a disposal facility by 2035. These canisters will be stored at the Idaho National Engineering and Environmental Laboratory until they are sent to a national geologic repository. The operating period for vitrification treatment will be from the end of 2015 through 2035

Combined effects of displacement damage and high gas content in aluminum

International Nuclear Information System (INIS)

Farrell, K.; Houston, J.T.

1976-01-01

A solid solution alloy of 2300 at. ppM of 6 Li isotope in aluminum was neutron irradiated at about 0.36 T/sub m/ in high, fast and thermal fluxes producing a damage level of 2 to 3 dpa and simultaneously inducing a gas content of about 2200 at. ppM each of helium and tritium from burnup of 6 Li. The gases significantly increased the nucleation of structural defects but did not change the degree of swelling; cavity concentrations were increased approximately 1000-fold, cavity sizes were decreased approximately 10-fold and there was approximately 10-fold increase in the concentrations of dislocations. Also, large cavities were developed on grain boundaries. The cavities were consistent with their being gas-filled bubbles. The refinement of damage structure by the gases caused a considerable increase in radiation hardening. Bend tests at 77 and 296 0 K revealed severe embrittlement and intergranular fracture. Comparison with data from material irradiated to produce comparable gas levels but relatively little displacement damage indicates that premature intergranular failure is much enhanced by the presence of a defect-hardened matrix. Postirradiation annealing tests showed the cavity and dislocation structures to have high resistance to annealing. Annealing also encouraged the development of a secondary population of large cavities believed to be associated with migration and precipitation of tritium

Combined effects of displacement damage and high gas content in aluminum

International Nuclear Information System (INIS)

Farrell, K.; Houston, J.T.

1976-05-01

A solid solution alloy of 2300 appm of 6 Li isotope in aluminum was neutron irradiated at about 0.36 T/sub m/ in high, fast and thermal fluxes producing a damage level of 2 to 3 dpa and simultaneously inducing a gas content of about 2200 appm each of helium and tritium from burnup of 6 Li. The gases significantly increased the nucleation of structural defects but did not change the degree of swelling; cavity concentrations were increased approximately 1000-fold, cavity sizes were decreased approximately 10-fold and there was approximately 10-fold increase in the concentrations of dislocations. Also, large cavities were developed on grain boundaries. The cavities were consistent with their being gas-filled bubbles. The refinement of damage structure by the gases caused a considerable increase in radiation hardening. Bend tests at 77 and 296 K revealed severe embrittlement and intergranular fracture. Comparison with data from material irradiated to produce comparable gas levels but relatively little displacement damage indicates that premature intergranular failure is much enhanced by the presence of a defect-hardened matrix. Postirradiation annealing tests showed the cavity and dislocation structures to have high resistance to annealing. Annealing also encouraged the development of a secondary population of large cavities believed to be associated with migration and precipitation of tritium

The effect of cellular carotenoid levels in micrococcus luteus on resistance to gamma radiation

International Nuclear Information System (INIS)

Al-Wandawi, K. H.

2000-01-01

In the present study, a biological system was developed to link the cellular carotenoid levels to Gamma radiation resistance in bacteria for the frst time. thus, in a non-photosynrhetic bacterium, in Micrococcus Luteus an inverse relationship was found between the increase in diphenylamine (DPA) concentration (5.25 μg/ml culture) and the polar cellular carotenoid pigments (C-45 and C-50 carotenoids and their glucosides). It was also found that irradiation of cells with different carotenoid concentrations with doses of γ-radiation in the range of (0.2500 gray) under oxic, air and hypoxic conditions showed that carotenoid pigments offer no significant protection as they usually do in case of visible light. (author).15 refs., 5 figs., 3 tabs

Final report on neutron irradiation at low temperature to investigate plastic instability and a high temperature to study cavitation

International Nuclear Information System (INIS)

Singh, B.N.; Eldrup, M.; Golubov, S.I.; Edwards, D.J.; Jung, P.

2005-01-01

Effects of neutron irradiation on defect accumulation and physical and mechanical properties of pure iron and F82H and EUROFER 97 ferritic-martensitic steels have been investigated. Tensile specimens were neutron irradiated to a dose level of 0,23 dpa at 333 and 573 K. Electrical resistivity and tensile properties were measured both in the unirradiated and irradiated condition. Some additional specimens of pure iron were irradiated at 333 K to doses of 10-3, 10-2 and 10-1 dpa and tensile tested at 333 K. To investigate the effect of helium on cavity nucleation and growth, specimens of pure iron and EUROFER 97 were implanted with different amounts of helium at 323 K and subsequently neutron irradiated to doses of 10-3, 10-2 and 10-1 dpa at 323 K. Defect microstructures were investigated using positron annihilation spectroscopy (PAS) and transmission electron microscopy (TEM). Numerical calculations, based on the production bias model (PBM) were carried out to study the details of evolution of cavities with and without helium generation. The phenomena of dislocation decoration and raft formation, which are important for understanding radiation hardening and plastic flow localization, have been studied using the Kinetic Monte Carlo (KMC) code during a realistic dynamic irradiation of bcc iron at 300 K. Molecular dynamics (MD) simulations have been carried out to study the stress dependencies of dislocation velocity and drag coefficient for an edge dislocation decorated with small SIA loops.The present report describes both experimental procedure and calculational methodology employed in the present work. The main results of all these investigations, both experimental and theoretical, are highlighted with appropriate examples. Finally, a brief summary is given of the main results conclusions. (au)

Radiation damage in stainless steel under varying temperature neutron irradiation

Energy Technology Data Exchange (ETDEWEB)

Yoshida, Naoaki [Kyushu Univ., Kasuga, Fukuoka (Japan). Research Inst. for Applied Mechanics

1998-03-01

Microstructural evolution of model alloys of 316SS was examined by neutron irradiation at JMTR under cyclic temperature varying condition. In the case of Fe-16Cr-17Ni, formation of interstitial loops and voids are strongly suppressed by varying the temperature from 473K to 673K. By adding Ti as miner element (0.25wt%), however, abnormal accumulation of vacancies (void swelling of 11%dpa at 0.1dpa) was observed. Theoretical analysis standing on the rate theory of defect clustering and simulation irradiation experiments with heavy ions indicates that the vacancy-rich condition which appears temporally during and after changing the temperature from low to high brings these results. It was also shown that only 1 dpa pre-irradiation at low temperature changes swelling behavior at high temperature above several 10 dpa. The understanding of non-steady-state defect processes under temperature varying irradiation is very important to estimate the radiation damage under fusion environment where short-term and long-term temperature variation is expected. (author)

High level nuclear wastes

International Nuclear Information System (INIS)

Lopez Perez, B.

1987-01-01

The transformations involved in the nuclear fuels during the burn-up at the power nuclear reactors for burn-up levels of 33.000 MWd/th are considered. Graphs and data on the radioactivity variation with the cooling time and heat power of the irradiated fuel are presented. Likewise, the cycle of the fuel in light water reactors is presented and the alternatives for the nuclear waste management are discussed. A brief description of the management of the spent fuel as a high level nuclear waste is shown, explaining the reprocessing and giving data about the fission products and their radioactivities, which must be considered on the vitrification processes. On the final storage of the nuclear waste into depth geological burials, both alternatives are coincident. The countries supporting the reprocessing are indicated and the Spanish programm defined in the Plan Energetico Nacional (PEN) is shortly reviewed. (author) 8 figs., 4 tabs

High spin levels in 151Ho

International Nuclear Information System (INIS)

Gizon, J.; Gizon, A.; Andre, S.; Genevey, J.; Jastrzebski, J.; Kossakowski, R.; Moszinski, M.; Preibisz, Z.

1981-02-01

We report here on the first study of the level structure of 151 Ho. High spin levels in 151 Ho have been populated in the 141 Pr + 16 O and 144 Sm + 12 C reactions. The level structure has been established up to 6.6 MeV energy and the spins and particles determined up to 49/2 - . Most of the proposed level configurations can be explained by the coupling of hsub(11/2) protons to fsub(7/2) and/or hsub(9/2) neutrons. An isomer with 14 +- 3 ns half-life and a delayed gamma multiplicity equal to 17 +- 2 has been found. Its spin is larger than 57/2 h units

Radiation transport in high-level waste form

International Nuclear Information System (INIS)

Arakali, V.S.; Barnes, S.M.

1992-01-01

The waste form selected for vitrifying high-level nuclear waste stored in underground tanks at West Valley, NY is borosilicate glass. The maximum radiation level at the surface of a canister filled with the high-level waste form is prescribed by repository design criteria for handling and disposition of the vitrified waste. This paper presents an evaluation of the radiation transport characteristics for the vitreous waste form expected to be produced at West Valley and the resulting neutron and gamma dose rates. The maximum gamma and neutron dose rates are estimated to be less than 7500 R/h and 10 mRem/h respectively at the surface of a West Valley canister filled with borosilicate waste glass

The ALICE Dimuon Spectrometer High Level Trigger

CERN Document Server

Becker, B; Cicalo, Corrado; Das, Indranil; de Vaux, Gareth; Fearick, Roger; Lindenstruth, Volker; Marras, Davide; Sanyal, Abhijit; Siddhanta, Sabyasachi; Staley, Florent; Steinbeck, Timm; Szostak, Artur; Usai, Gianluca; Vilakazi, Zeblon

2009-01-01

The ALICE Dimuon Spectrometer High Level Trigger (dHLT) is an on-line processing stage whose primary function is to select interesting events that contain distinct physics signals from heavy resonance decays such as J/psi and Gamma particles, amidst unwanted background events. It forms part of the High Level Trigger of the ALICE experiment, whose goal is to reduce the large data rate of about 25 GB/s from the ALICE detectors by an order of magnitude, without loosing interesting physics events. The dHLT has been implemented as a software trigger within a high performance and fault tolerant data transportation framework, which is run on a large cluster of commodity compute nodes. To reach the required processing speeds, the system is built as a concurrent system with a hierarchy of processing steps. The main algorithms perform partial event reconstruction, starting with hit reconstruction on the level of the raw data received from the spectrometer. Then a tracking algorithm finds track candidates from the recon...

Current high-level waste solidification technology

International Nuclear Information System (INIS)

Bonner, W.F.; Ross, W.A.

1976-01-01

Technology has been developed in the U.S. and abroad for solidification of high-level waste from nuclear power production. Several processes have been demonstrated with actual radioactive waste and are now being prepared for use in the commercial nuclear industry. Conversion of the waste to a glass form is favored because of its high degree of nondispersibility and safety

The CMS High-Level Trigger

International Nuclear Information System (INIS)

Covarelli, R.

2009-01-01

At the startup of the LHC, the CMS data acquisition is expected to be able to sustain an event readout rate of up to 100 kHz from the Level-1 trigger. These events will be read into a large processor farm which will run the 'High-Level Trigger'(HLT) selection algorithms and will output a rate of about 150 Hz for permanent data storage. In this report HLT performances are shown for selections based on muons, electrons, photons, jets, missing transverse energy, τ leptons and b quarks: expected efficiencies, background rates and CPU time consumption are reported as well as relaxation criteria foreseen for a LHC startup instantaneous luminosity.

The CMS High-Level Trigger

CERN Document Server

Covarelli, Roberto

2009-01-01

At the startup of the LHC, the CMS data acquisition is expected to be able to sustain an event readout rate of up to 100 kHz from the Level-1 trigger. These events will be read into a large processor farm which will run the "High-Level Trigger" (HLT) selection algorithms and will output a rate of about 150 Hz for permanent data storage. In this report HLT performances are shown for selections based on muons, electrons, photons, jets, missing transverse energy, tau leptons and b quarks: expected efficiencies, background rates and CPU time consumption are reported as well as relaxation criteria foreseen for a LHC startup instantaneous luminosity.

The CMS High-Level Trigger

Science.gov (United States)

Covarelli, R.

2009-12-01

At the startup of the LHC, the CMS data acquisition is expected to be able to sustain an event readout rate of up to 100 kHz from the Level-1 trigger. These events will be read into a large processor farm which will run the "High-Level Trigger" (HLT) selection algorithms and will output a rate of about 150 Hz for permanent data storage. In this report HLT performances are shown for selections based on muons, electrons, photons, jets, missing transverse energy, τ leptons and b quarks: expected efficiencies, background rates and CPU time consumption are reported as well as relaxation criteria foreseen for a LHC startup instantaneous luminosity.

Development of New Heats of Advanced Ferritic/Martensitic Alloys

Energy Technology Data Exchange (ETDEWEB)

Maloy, Stuart Andrew [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Pestovich, Kimberly Shay [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Anderoglu, Osman [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Aydogan, Eda [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2017-06-23

The Fuel Cycle Research and Development program is investigating methods of transmuting minor actinides in various fuel cycle options. To achieve this goal, new fuels and cladding materials must be developed and tested to high burnup levels (e.g. >20%) requiring cladding to withstand very high doses (greater than 200 dpa) while in contact with the coolant and the fuel. To develop and qualify materials to a total fluence greater than 200 dpa requires development of advanced alloys and irradiations in fast reactors to test these alloys. Recent results from testing numerous ferritic/martensitic steels at low temperatures suggest that improvements in low temperature radiation tolerance can be achieved through carefully controlling the nitrogen content in these alloys. Thus, four new heats of HT-9 were produced with controlled nitrogen content: two by Metalwerks and two by Sophisticated Alloys. Initial results on these new alloys are presented including microstructural analysis and hardness testing. Future testing will include irradiation testing with ions and in reactor.

Radiation induced phosphorus segregation in austenitic and ferritic alloys

International Nuclear Information System (INIS)

Brimhall, J.L.; Baer, D.R.; Jones, R.H.

1984-01-01

The radiation induced surface segregation (RIS) of phosphorus in stainless steel attained a maximum at a dose of 0.8 dpa then decreased continually with dose. This decrease in the surface segregation of phosphorus at high dose levels has been attributed to removal of the phosphorus layer by ion sputtering. Phosphorus is not replenished since essentially all of the phosphorus within the irradiation zone has been segregated to the surface. Sputter removal can explain the previously reported absence of phosphorus segregation in ferritic alloys irradiated at high dosessup(1,2) (>1 dpa) since irradiation of ferritic alloys to low doses has shown measurable RIS. This sputtering phenomenon places an inherent limitation to the heavy ion irradiation technique for the study of surface segregation of impurity elements. The magnitude of the segregation in ferritics is still much less than in stainless steel which can be related to the low damage accumulation in these alloys. (orig.)

SIGWX Charts - High Level Significant Weather

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — High level significant weather (SIGWX) forecasts are provided for the en-route portion of international flights. NOAA's National Weather Service Aviation Center...

Saturation behavior of irradiation hardening in F82H irradiated in the HFIR

Energy Technology Data Exchange (ETDEWEB)

Hirose, T. [Blanket Engineering Group, Japan Atomic Energy Agency, Naka, Ibaraki (Japan); Shiba, K.; Tanigawa, H.; Ando, M. [Japan Atomic Energy Agency, Tokai-mura, Naga-gun, Ibaraki-ken (Japan); Klueh, R.L. [Oak Ridge National Laboratory, TN (United States); Stoller, R. [ORNL - Oak Ridge National Laboratory, Materials Science and Technology Div., Oak Ridge, AK TN (United States)

2007-07-01

Full text of publication follows: Post irradiation tensile tests on reduced activation ferritic/martensitic steel, F82H have been conducted over the past two decades using Japan Materials Testing Reactor (JMTR) of JAEA, and Fast Flux Testing Facility (FFTF) of PNNL and High Flux Isotope Reactor (HFIR) of ORNL, USA, under Japan/US collaboration programs. According to these results, F82H does not demonstrate irradiation hardening above 673 K up to 60 dpa. The current study has been concentrated on hardening behavior at temperature around 573 K. A series of low temperature irradiation experiment has been conducted at the HFIR under the international collaborative research between JAEA/US-DOE. In this collaboration, the irradiation condition is precisely controlled by the well matured capsule designing and instrumentation. This paper summarizes recent results of the irradiation experiments focused on F82H and its modified steels compared with the irradiation properties database on F82H. Post irradiation tensile tests have been conducted on the F82H and its modified steels irradiated at 573 K and the dose level was up to 25 dpa. According to these results, irradiation hardening of F82H is saturated by 9 dpa and the as-irradiated 0.2 % proof stress is less than 1 GPa at ambient temperature. The deterioration of total elongation was also saturated by 9 dpa irradiation. The ductility of some modified steels which showed larger total elongation than that of F82H before irradiation become the same level as that of standard F82H steel after irradiation, even though its magnitude of irradiation hardening is smaller than that of F82H. This suggests that the more ductile steel demonstrates the more ductility loss at this temperature, regardless to the hardening level. The difference in ductility loss behavior between various tensile specimens will be discussed as the ductility could depend on the specimen dimension. (authors)

Ramifications of defining high-level waste

International Nuclear Information System (INIS)

Wood, D.E.; Campbell, M.H.; Shupe, M.W.

1987-01-01

The Nuclear Regulatory Commission (NRC) is considering rule making to provide a concentration-based definition of high-level waste (HLW) under authority derived from the Nuclear Waste Policy Act (NWPA) of 1982 and the Low Level Waste Policy Amendments Act of 1985. The Department of Energy (DOE), which has the responsibility to dispose of certain kinds of commercial waste, is supporting development of a risk-based classification system by the Oak Ridge National Laboratory to assist in developing and implementing the NRC rule. The system is two dimensional, with the axes based on the phrases highly radioactive and requires permanent isolation in the definition of HLW in the NWPA. Defining HLW will reduce the ambiguity in the present source-based definition by providing concentration limits to establish which materials are to be called HLW. The system allows the possibility of greater-confinement disposal for some wastes which do not require the degree of isolation provided by a repository. The definition of HLW will provide a firm basis for waste processing options which involve partitioning of waste into a high-activity stream for repository disposal, and a low-activity stream for disposal elsewhere. Several possible classification systems have been derived and the characteristics of each are discussed. The Defense High Level Waste Technology Lead Office at DOE - Richland Operations Office, supported by Rockwell Hanford Operations, has coordinated reviews of the ORNL work by a technical peer review group and other DOE offices. The reviews produced several recommendations and identified several issues to be addressed in the NRC rule making. 10 references, 3 figures

(n-3) fatty acids and cardiovascular health: are effects of EPA and DHA shared or complementary?

Science.gov (United States)

Mozaffarian, Dariush; Wu, Jason H Y

2012-03-01

Considerable research supports cardiovascular benefits of consuming omega-3 PUFA, also known as (n-3) PUFA, from fish or fish oil. Whether individual long-chain (n-3) PUFA have shared or complementary effects is not well established. We reviewed evidence for dietary and endogenous sources and cardiovascular effects on biologic pathways, physiologic risk factors, and clinical endpoints of EPA [20:5(n-3)], docosapentaenoic acid [DPA, 22:5(n-3)], and DHA [22:6(n-3)]. DHA requires direct dietary consumption, with little synthesis from or retroconversion to DPA or EPA. Whereas EPA is also largely derived from direct consumption, EPA can also be synthesized in small amounts from plant (n-3) precursors, especially stearidonic acid. In contrast, DPA appears principally derived from endogenous elongation from EPA, and DPA can also undergo retroconversion back to EPA. In experimental and animal models, both EPA and DHA modulate several relevant biologic pathways, with evidence for some differential benefits. In humans, both fatty acids lower TG levels and, based on more limited studies, favorably affect cardiac diastolic filling, arterial compliance, and some metrics of inflammation and oxidative stress. All three (n-3) PUFA reduce ex vivo platelet aggregation and DHA also modestly increases LDL and HDL particle size; the clinical relevance of such findings is uncertain. Combined EPA+DHA or DPA+DHA levels are associated with lower risk of fatal cardiac events and DHA with lower risk of atrial fibrillation, suggesting direct or indirect benefits of DHA for cardiac arrhythmias (although not excluding similar benefits of EPA or DPA). Conversely, EPA and DPA, but not DHA, are associated with lower risk of nonfatal cardiovascular endpoints in some studies, and purified EPA reduced risk of nonfatal coronary syndromes in one large clinical trial. Overall, for many cardiovascular pathways and outcomes, identified studies of individual (n-3) PUFA were relatively limited, especially

(n-3) Fatty Acids and Cardiovascular Health: Are Effects of EPA and DHA Shared or Complementary?123

Science.gov (United States)

Mozaffarian, Dariush; Wu, Jason H. Y.

2012-01-01

Considerable research supports cardiovascular benefits of consuming omega-3 PUFA, also known as (n-3) PUFA, from fish or fish oil. Whether individual long-chain (n-3) PUFA have shared or complementary effects is not well established. We reviewed evidence for dietary and endogenous sources and cardiovascular effects on biologic pathways, physiologic risk factors, and clinical endpoints of EPA [20:5(n-3)], docosapentaenoic acid [DPA, 22:5(n-3)], and DHA [22:6(n-3)]. DHA requires direct dietary consumption, with little synthesis from or retroconversion to DPA or EPA. Whereas EPA is also largely derived from direct consumption, EPA can also be synthesized in small amounts from plant (n-3) precursors, especially stearidonic acid. In contrast, DPA appears principally derived from endogenous elongation from EPA, and DPA can also undergo retroconversion back to EPA. In experimental and animal models, both EPA and DHA modulate several relevant biologic pathways, with evidence for some differential benefits. In humans, both fatty acids lower TG levels and, based on more limited studies, favorably affect cardiac diastolic filling, arterial compliance, and some metrics of inflammation and oxidative stress. All three (n-3) PUFA reduce ex vivo platelet aggregation and DHA also modestly increases LDL and HDL particle size; the clinical relevance of such findings is uncertain. Combined EPA+DHA or DPA+DHA levels are associated with lower risk of fatal cardiac events and DHA with lower risk of atrial fibrillation, suggesting direct or indirect benefits of DHA for cardiac arrhythmias (although not excluding similar benefits of EPA or DPA). Conversely, EPA and DPA, but not DHA, are associated with lower risk of nonfatal cardiovascular endpoints in some studies, and purified EPA reduced risk of nonfatal coronary syndromes in one large clinical trial. Overall, for many cardiovascular pathways and outcomes, identified studies of individual (n-3) PUFA were relatively limited, especially

High dose radiation damage in nuclear energy structural materials investigated by heavy ion irradiation simulation

International Nuclear Information System (INIS)

Zheng Yongnan; Xu Yongjun; Yuan Daqing

2014-01-01

Structural materials in ITER, ADS and fast reactor suffer high dose irradiations of neutrons and/or protons, that leads to severe displacement damage up to lOO dpa per year. Investigation of radiation damage induced by such a high dose irradiation has attracted great attention along with the development of nuclear energy facilities of new generation. However, it is deeply hampered for the lacking of high dose neutron and proton sources. Irradiation simulation of heavy ions produced by accelerators opens up an effective way for laboratory investigation of high dose irradiation induced radiation damage encountered in the ITER, ADS, etc. Radiation damage is caused mainly by atomic displacement in materials. The displacement rate of heavy ions is about lO 3 ∼10 7 orders higher than those of neutrons and protons. High displacement rate of heavy ions significantly reduces the irradiation time. The heavy ion irradiation simulation technique (HIIS) technique has been developed at China Institute of Atomic Energy and a series of the HIIS experiments have been performed to investigate radiation damage in stainless steels, tungsten and tantalum at irradiation temperatures from room temperature to 800 ℃ and in the irradiation dose region up to 100 dpa. The experimental results show that he radiation swelling peak for the modified stainless steel appears in the temperature region around 580 ℃ and the radiation damage is more sensitive to the temperature, the size of the radiation induced vacancy cluster or void increase with the increasing of the irradiation dose, and among the three materials the home-made modified stainless steel has the best radiation resistant property. (authors)

Production and properties of solidified high-level waste

International Nuclear Information System (INIS)

Brodersen, K.

1980-08-01

Available information on production and properties of solidified high-level waste are presented. The review includes literature up to the end of 1979. The feasibility of production of various types of solidified high-level wast is investigated. The main emphasis is on borosilicate glass but other options are also mentioned. The expected long-term behaviour of the materials are discussed on the basis of available results from laboratory experiments. Examples of the use of the information in safety analysis of disposal in salt formations are given. The work has been made on behalf of the Danish utilities investigation of the possibilities of disposal of high-level waste in salt domes in Jutland. (author)

Tensile and low cycle fatigue properties of EUROFER97-steel after 16.3 dpa neutron irradiation at 523, 623 and 723 K

Energy Technology Data Exchange (ETDEWEB)

Materna-Morris, E., E-mail: edeltraud.materna-morris@kit.edu; Möslang, A., E-mail: anton.moeslang@kit.edu; Schneider, H.-C., E-mail: hans-christian.schneider@kit.edu

2013-11-15

Neutron-irradiated specimens of the reduced-activation tempered martensitic steel EUROFER97 were tested by tensile and low cycle conditions to detect the impact of irradiation on strength and lifetime. The irradiation temperature ranged from 523 to 723 K with an accumulated dose of up to 16.3 dpa. Tensile tests revealed a significant irradiation-induced hardening below 673 K with a peak of ∼430 MPa at 573 K but none was seen at 723 K, as expected. Despite the significant irradiation-induced reduction of uniform elongation, the total elongation is only reduced by about 50% below 673 K. Post-irradiation strain-controlled fatigue tests have been carried out at T{sub irrad} = T{sub test} = 523, 623 and 723 K. Pronounced cyclic softening was observed in all specimens. At 623 and 723 K, neutron irradiation had no effect on fatigue life within the data scatter. A significant lifetime increase has been observed at T{sub irrad} = T{sub test} = 523 K that advances with decreasing stress amplitude Δε (1% → 0.5%) up to a factor of ten. Scanning electron microscopy (SEM) analysis revealed ductile fracture and fatigue striations on the fracture surfaces. After push–pull fatigue testing, transmission electron microscopy (TEM) investigations showed the typical sub-cell formation, even at T{sub irrad} = T{sub test} = 523 K.

Photo-driven electron transfer from the highly reducing excited state of naphthalene diimide radical anion to a CO ₂ reduction catalyst within a molecular triad

Energy Technology Data Exchange (ETDEWEB)

Martinez, Jose F. [Department of Chemistry and Argonne-Northwestern Solar Energy Research (ANSER) Center; Northwestern University; Evanston; USA; La Porte, Nathan T. [Department of Chemistry and Argonne-Northwestern Solar Energy Research (ANSER) Center; Northwestern University; Evanston; USA; Mauck, Catherine M. [Department of Chemistry and Argonne-Northwestern Solar Energy Research (ANSER) Center; Northwestern University; Evanston; USA; Wasielewski, Michael R. [Department of Chemistry and Argonne-Northwestern Solar Energy Research (ANSER) Center; Northwestern University; Evanston; USA

2017-01-01

The naphthalene-1,4:5,8-bis(dicarboximide) radical anion (NDI^-˙), which is easily produced by mild chemical or electrochemical reduction (-0.5 Vvs.SCE), can be photoexcited at wavelengths as long as 785 nm, and has an excited state (NDI^-˙*) oxidation potential of -2.1 Vvs.SCE, making it a very attractive choice for artificial photosynthetic systems that require powerful photoreductants, such as CO₂ reduction catalysts. However, once an electron is transferred from NDI^-˙* to an acceptor directly bound to it, a combination of strong electronic coupling and favorable free energy change frequently make the back electron transfer rapid. To mitigate this effect, we have designed a molecular triad system comprising an NDI^-˙ chromophoric donor, a 9,10-diphenylanthracene (DPA) intermediate acceptor, and a Re(dmb)(CO)₃carbon dioxide reduction catalyst, where dmb is 4,4'-dimethyl-2,2'-bipyridine, as the terminal acceptor. Photoexcitation of NDI^-˙ to NDI^-˙* is followed by ultrafast reduction of DPA to DPA^-˙, which then rapidly reduces the metal complex. The overall time constant for the forward electron transfer to reduce the metal complex is τ = 20.8 ps, while the time constant for back-electron transfer is six orders of magnitude longer, τ = 43.4 μs. Achieving long-lived, highly reduced states of these metal complexes is a necessary condition for their use as catalysts. The extremely long lifetime of the reduced metal complex is attributed to careful tuning of the redox potentials of the chromophore and intermediate acceptor. The NDI^-˙–DPA fragment presents many attractive features for incorporation into other photoinduced electron transfer assemblies directed at the long-lived photosensitization of difficult-to-reduce catalytic centers.

Translation of a High-Level Temporal Model into Lower Level Models: Impact of Modelling at Different Description Levels

DEFF Research Database (Denmark)

Kraft, Peter; Sørensen, Jens Otto

2001-01-01

given types of properties, and examine how descriptions on higher levels translate into descriptions on lower levels. Our example looks at temporal properties where the information is concerned with the existence in time. In a high level temporal model with information kept in a three-dimensional space...... the existences in time can be mapped precisely and consistently securing a consistent handling of the temporal properties. We translate the high level temporal model into an entity-relationship model, with the information in a two-dimensional graph, and finally we look at the translations into relational...... and other textual models. We also consider the aptness of models that include procedural mechanisms such as active and object databases...

Elastic and inelastic light scattering from single bacterial spores in an optical trap allows the monitoring of spore germination dynamics

OpenAIRE

Peng, Lixin; Chen, De; Setlow, Peter; Li, Yong-qing

2009-01-01

Raman scattering spectroscopy and elastic light scattering intensity (ESLI) were used to simultaneously measure levels of Ca-dipicolinic acid (CaDPA) and changes in spore morphology and refractive index during germination of individual B. subtilis spores with and without the two redundant enzymes (CLEs), CwlJ and SleB, that degrade spores’ peptidoglycan cortex. Conclusions from these measurements include: 1) CaDPA release from individual wild-type germinating spores was biphasic; in a first h...

Evaluation of radionuclide concentrations in high-level radioactive wastes

International Nuclear Information System (INIS)

Fehringer, D.J.

1985-10-01

This report describes a possible approach for development of a numerical definition of the term ''high-level radioactive waste.'' Five wastes are identified which are recognized as being high-level wastes under current, non-numerical definitions. The constituents of these wastes are examined and the most hazardous component radionuclides are identified. This report suggests that other wastes with similar concentrations of these radionuclides could also be defined as high-level wastes. 15 refs., 9 figs., 4 tabs

Timing of High-level Waste Disposal

International Nuclear Information System (INIS)

2008-01-01

This study identifies key factors influencing the timing of high-level waste (HLW) disposal and examines how social acceptability, technical soundness, environmental responsibility and economic feasibility impact on national strategies for HLW management and disposal. Based on case study analyses, it also presents the strategic approaches adopted in a number of national policies to address public concerns and civil society requirements regarding long-term stewardship of high-level radioactive waste. The findings and conclusions of the study confirm the importance of informing all stakeholders and involving them in the decision-making process in order to implement HLW disposal strategies successfully. This study will be of considerable interest to nuclear energy policy makers and analysts as well as to experts in the area of radioactive waste management and disposal. (author)

High-Level Waste Melter Study Report

Energy Technology Data Exchange (ETDEWEB)

Perez, Joseph M.; Bickford, Dennis F.; Day, Delbert E.; Kim, Dong-Sang; Lambert, Steven L.; Marra, Sharon L.; Peeler, David K.; Strachan, Denis M.; Triplett, Mark B.; Vienna, John D.; Wittman, Richard S.

2001-07-13

At the Hanford Site in Richland, Washington, the path to site cleanup involves vitrification of the majority of the wastes that currently reside in large underground tanks. A Joule-heated glass melter is the equipment of choice for vitrifying the high-level fraction of these wastes. Even though this technology has general national and international acceptance, opportunities may exist to improve or change the technology to reduce the enormous cost of accomplishing the mission of site cleanup. Consequently, the U.S. Department of Energy requested the staff of the Tanks Focus Area to review immobilization technologies, waste forms, and modifications to requirements for solidification of the high-level waste fraction at Hanford to determine what aspects could affect cost reductions with reasonable long-term risk. The results of this study are summarized in this report.

Swelling of austenitic iron-nickelchromium ternary alloys during fast neutron irradiation

International Nuclear Information System (INIS)

Garner, F.A.; Brager, H.R.

1984-01-01

Swelling data are now available for 15 iron-nickel-chromium ternary alloys irradiated to exposures as high as 110 displacements per atom (dpa) in Experimental Breeder Reactor-II (EBR-II) between 400 and 650 0 C. These data confirm trends observed at lower exposure levels and extend the generality of earlier conclusions to cover a broader range of composition and temperature. It appears that all austenitic iron-nickel-chromium ternary alloys eventually approach an intrinsic swelling rate of about1%/dpa over a range of temperature even wider than studied in this experiment. The duration of the transient regime that precedes the attainment of this rate is quite sensitive to nickel and chromium content, however. At nickel and chromium levels typical of 300 series steels, swelling does not saturate at engineering-relevant levels. However, there appears to be a tendency toward saturation that increases with declining temperature, increasing nickel and decreasing chromium levels. Comparisons of these results are made with those of similar studies conducted with charged particles. Conclusions are then drawn concerning the validity of charged particle simulation studies to determine the compositional and temperature dependence of swelling

Synergies Between ' and Cavity Formation in HT-9 Following High Dose Neutron Irradiation

Energy Technology Data Exchange (ETDEWEB)

Field, Kevin G. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Parish, Chad M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Saleh, Tarik A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Eftink, Benjamin P. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

2017-06-01

Candidate cladding materials for advanced nuclear power reactors including fast reactor designs require materials capable of withstanding high dose neutron irradiation at elevated temperatures. One candidate material, HT-9, through various research programs have demonstrated the ability to withstand significant swelling and other radiation-induced degradation mechanisms in the high dose regime (>50 displacements per atom, dpa) at elevated temperatures (>300 C). Here, high efficiency multi-dimensional scanning transmission electron microscopy (STEM) acquisition with the aid of a three-dimensional (3D) reconstruction and modeling technique is used to probe the microstructural features that contribute to the exceptional swelling resistance of HT-9. In particular, the synergies between ' and fine-scale and moderate-scale cavity formation is investigated.

Microstructural examination of irradiated vanadium alloys

Energy Technology Data Exchange (ETDEWEB)

Gelles, D.S. [Pacific Northwest National Lab., Richland, WA (United States); Chung, H.M. [Argonne National Lab., IL (United States)

1997-04-01

Microstructural examination results are reported for a V-5Cr-5Ti unirradiated control specimens of heat BL-63 following annealing at 1050{degrees}C, and V-4Cr-4Ti heat BL-47 irradiated in three conditions from the DHCE experiment: at 425{degrees}C to 31 dpa and 0.39 appm He/dpa, at 600{degrees}C to 18 dpa and 0.54 appm He/dpa and at 600{degrees}C to 18 dpa and 4.17 appm He/dpa.

Sterilization, high-level disinfection, and environmental cleaning.

Science.gov (United States)

Rutala, William A; Weber, David J

2011-03-01

Failure to perform proper disinfection and sterilization of medical devices may lead to introduction of pathogens, resulting in infection. New techniques have been developed for achieving high-level disinfection and adequate environmental cleanliness. This article examines new technologies for sterilization and high-level disinfection of critical and semicritical items, respectively, and because semicritical items carry the greatest risk of infection, the authors discuss reprocessing semicritical items such as endoscopes and automated endoscope reprocessors, endocavitary probes, prostate biopsy probes, tonometers, laryngoscopes, and infrared coagulation devices. In addition, current issues and practices associated with environmental cleaning are reviewed. Copyright © 2011. Published by Elsevier Inc.

The LH2 complexes are assembled in the cells of purple sulfur bacterium Ectothiorhodospira haloalkaliphila with inhibition of carotenoid biosynthesis.

Science.gov (United States)

Ashikhmin, Aleksandr; Makhneva, Zoya; Moskalenko, Andrey

2014-03-01

The effect of the inhibitor of carotenoid (Car) biosynthesis, diphenylamine (DPA), on the cells of the purple sulfur bacterium Ectothiorhodospira (Ect.) haloalkaliphila has been studied. There occurs an inhibition of the biosynthesis of colored Cars (≥99 %) at 71 μM DPA. Considering "empty" Car pockets (Moskalenko and Makhneva 2012) the content of Cars in the DPA-treated samples is first calculated more correctly. The total content of the colored Cars in the sample at 71 μM DPA does not exceed 1 % of the wild type. In the DPA-treated cells (membranes) a complete set of pigment-protein complexes is retained. The LH2 complex at 71 μM DPA is isolated, which is identical to the LH2 complex of the wild type in near IR absorption spectra. This suggests that the principles for assembling this LH2 complex in vivo in the absence of colored Cars remain the same. These results are in full agreement with the data obtained earlier for Allochromatium (Alc.) minutissimum (Moskalenko and Makhneva 2012). They are as follows: (1) DPA almost entirely inhibits the biosynthesis of the colored Cars in Ect. haloalkaliphila cells. (2) In the DPA-treated samples non-colored Cars are detected at 53.25 μM DPA (as traces) and at 71 μM DPA. (3) DPA may affect both phytoene synthase (at ≤71 μM DPA) and phytoene desaturase (at ≥53.25 μM DPA). (4) The assembly of LH2 complex does occur without any colored Cars.

High level of CA 125 due to large endometrioma.

Science.gov (United States)

Phupong, Vorapong; Chen, Orawan; Ultchaswadi, Pornthip

2004-09-01

CA 125 is a tumor-associated antigen. Its high levels are usually associated with ovarian malignancies, whereas smaller increases in the levels were associated with benign gynecologic conditions. The authors report a high level of CA 125 in a case of large ovarian endometrioma. A 45-year-old nulliparous Thai woman, presented with an increase of her abdominal girth for 7 months. Transabdominal ultrasonogram demonstrated a large ovarian cyst and multiple small leiomyoma uteri, and serum CA 125 level was 1,006 U/ml. The preoperative diagnosis was ovarian cancer with leiomyoma uteri. Exploratory laparotomy was performed. There were a large right ovarian endometrioma, small left ovarian endometrioma and multiple small leiomyoma. Total abdominal hysterectomy and bilateral salpingo-oophorectomy was performed and histopathology confirmed the diagnosis of endometrioma and leiomyoma. The serum CA 125 level declined to non-detectable at the 4th week. She was well at discharge and throughout her 4th week follow-up period Although a very high level of CA 125 is associated with a malignant process, it can also be found in benign conditions such as a large endometrioma. The case emphasizes the association of high levels of CA 125 with benign gynecologic conditions.

Development of high nickel austenitic steels for the application to fast reactor cores, (I). Alloy design with the aid of the d-electrons concept

International Nuclear Information System (INIS)

Murata, Yoshinori; Morinaga, Masahiko; Yukawa, Natsuo; Ukai, Shigeharu; Nomura, Shigeo; Okuda, Takanari; Harada, Makoto

1999-01-01

The design of high nickel austenitic steels for the core materials of the fast reactors was performed following the d-electrons concept devised on the basis of molecular orbital calculations of transition-metal based alloys. In this design two calculated parameters are mainly utilized. The one is the d-orbital energy level (Md) of alloying transition elements, and the other is the bond order (Bo) that is a measure of the covalent bond strength between atoms. Using the Md-bar - Bo-bar phase stability diagram accurate prediction become possible for the phase stability of the austenite phase and 5% swelling at 140 dpa for nickel ions. Here, Md-bar and Bo-bar are the compositional average of Md and Bo parameters, respectively. On the basis of the phase stability diagram and preliminary experiments, guidelines for the alloy design of carbo-nitrides precipitated high nickel austenitic steels were constructed. Following the guidelines several new austenitic steels were designed for the fast reactors core material. (author)

The effect of fusion-relevant helium levels on the mechanical properties of isotopically tailored ferritic alloys

Energy Technology Data Exchange (ETDEWEB)

Hankin, G.L. [Loughborough Univ. (United Kingdom); Hamilton, M.L.; Gelles, D.S. [Pacific Northwest National Lab., Richland, WA (United States)] [and others

1997-04-01

The yield and maximum strengths of an irradiated series of isotopically tailored ferritic alloys were evaluated using the shear punch test. The composition of three of the alloys was Fe-12Cr-1.5Ni. Different balances of nickel isotopes were used in each alloy in order to produce different helium levels. A fourth alloy, which contained no nickel, was also irradiated. The addition of nickel at any isotopic balance to the Fe-12Cr base alloy significantly increased the shear yield and maximum strengths of the alloys, and as expected, the strength of the alloys decreased with increasing irradiation temperature. Helium itself, up to 75 appm over 7 dpa appears to have little effect on the mechanical properties of the alloys.

Precipitation response of austenitic stainless steel to simulated fusion irradiation

International Nuclear Information System (INIS)

Maziasz, P.J.

1978-01-01

The precipitation response of annealed type 316 stainless steel irradiated in HFIR is studied and compared to previously observed thermal aging and fast reactor irradiation responses. Irradiation in HFIR simultaneously produces high levels of helium and displacement damage and partially simulates a fusion environment. Samples have been irradiated at temperatures from 550 to 680 0 C to fluences producing up to 3300 appm He and 47 dpa

The sleep of elite athletes at sea level and high altitude: a comparison of sea-level natives and high-altitude natives (ISA3600).

Science.gov (United States)

Roach, Gregory D; Schmidt, Walter F; Aughey, Robert J; Bourdon, Pitre C; Soria, Rudy; Claros, Jesus C Jimenez; Garvican-Lewis, Laura A; Buchheit, Martin; Simpson, Ben M; Hammond, Kristal; Kley, Marlen; Wachsmuth, Nadine; Gore, Christopher J; Sargent, Charli

2013-12-01

Altitude exposure causes acute sleep disruption in non-athletes, but little is known about its effects in elite athletes. The aim of this study was to examine the effects of altitude on two groups of elite athletes, that is, sea-level natives and high-altitude natives. Sea-level natives were members of the Australian under-17 soccer team (n=14). High-altitude natives were members of a Bolivian under-20 club team (n=12). Teams participated in an 18-day (19 nights) training camp in Bolivia, with 6 nights at near sea level in Santa Cruz (430 m) and 13 nights at high altitude in La Paz (3600 m). Sleep was assessed on every day/night using activity monitors. The Australians' sleep was shorter, and of poorer quality, on the first night at altitude compared with sea level. Sleep quality returned to normal by the end of the first week at altitude, but sleep quantity had still not stabilised at its normal level after 2 weeks. The quantity and quality of sleep obtained by the Bolivians was similar, or greater, on all nights at altitude compared with sea level. The Australians tended to obtain more sleep than the Bolivians at sea level and altitude, but the quality of the Bolivians' sleep tended to be better than that of the Australians at altitude. Exposure to high altitude causes acute and chronic disruption to the sleep of elite athletes who are sea-level natives, but it does not affect the sleep of elite athletes who are high-altitude natives.

Investigation of high-energy-proton effects in aluminum

International Nuclear Information System (INIS)

Czajkowski, C.J.; Snead, C.L. Jr.; Todosow, M.

1997-01-01

Specimens of 1100 aluminum were exposed to several fluences of 23.5-GeV protons at the Brookhaven Alternating Gradient Synchrotron. Although this energy is above those currently being proposed for spallation-neutron applications, the results can be viewed as indicative of trends and other microstructural evolution with fluence that take place with high-energy proton exposures such as those associated with an increasing ratio of gas generation to dpa. TEM investigation showed significantly larger bubble size and lower density of bubbles compared with lower-energy proton results. Additional testing showed that the tensile strength increased with fluence as expected, but the microhardness decreased, a result for which an intepretation is still under investigation

Charpy impact test results of ferritic alloys from the HFIR[High Flux Isotope Reactor]-MFE-RB2 test

International Nuclear Information System (INIS)

Hu, W.L.; Gelles, D.S.

1987-03-01

Miniature Charpy specimens of HT-9 in base metal, weld metal and heat affected zone (HAZ) metal conditions, and 9Cr-1Mo in base metal and weld metal conditions have been tested following irradiation in HFIR-MFE-RB2 at 55 0 C to ≅10 dpa. All specimen conditions have degraded properties (both DBTT and USE) in comparison with specimens irradiated to lower dose. 9Cr-Mo degraded more than HT-9 and weld metal performed worse than base metal which performed worse than HAZ material. Property degradation was approximately linear as a function of dose, indicating that degradation response had not saturated by 10 dpa

The measurement for level of marine high-temperature and high-pressure vessels

International Nuclear Information System (INIS)

Lin Jie.

1986-01-01

The various error factors in measurement for level of marine high-temperature and high-pressure vessels are anslysed. The measuring method of error self compensation and its simplification for land use are shown

Final repositories for high-level radioactive waste; Endlagerung hochradioaktiver Abfaelle

Energy Technology Data Exchange (ETDEWEB)

NONE

2015-10-15

The brochure on final repositories for high-level radioactive waste covers the following issues: What is the origin of radioactive wastes? How large are the waste amounts? What is going to happen with the wastes? What is the solution for the Waste disposal? A new site search is started. Safety requirements for the final disposal of high-level radioactive wastes. Comparison of host rocks. Who is responsible and who will pay? Final disposal of high-level radioactive wastes worldwide. Short summary: History of the search for a final repository for high-level radioactive wastes in Germany.

The high level vibration test program

International Nuclear Information System (INIS)

Hofmayer, C.H.; Curreri, J.R.; Park, Y.J.; Kato, W.Y.; Kawakami, S.

1989-01-01

As part of cooperative agreements between the US and Japan, tests have been performed on the seismic vibration table at the Tadotsu Engineering Laboratory of Nuclear Power Engineering Test Center (NUPEC) in Japan. The objective of the test program was to use the NUPEC vibration table to drive large diameter nuclear power piping to substantial plastic strain with an earthquake excitation and to compare the results with state-of-the-art analysis of the problem. The test model was subjected to a maximum acceleration well beyond what nuclear power plants are designed to withstand. A modified earthquake excitation was applied and the excitation level was increased carefully to minimize the cumulative fatigue damage due to the intermediate level excitations. Since the piping was pressurized, and the high level earthquake excitation was repeated several times, it was possible to investigate the effects of ratchetting and fatigue as well. Elastic and inelastic seismic response behavior of the test model was measured in a number of test runs with an increasing excitation input level up to the limit of the vibration table. In the maximum input condition, large dynamic plastic strains were obtained in the piping. Crack initiation was detected following the second maximum excitation run. Crack growth was carefully monitored during the next two additional maximum excitation runs. The final test resulted in a maximum crack depth of approximately 94% of the wall thickness. The HLVT (high level vibration test) program has enhanced understanding of the behavior of piping systems under severe earthquake loading. As in other tests to failure of piping components, it has demonstrated significant seismic margin in nuclear power plant piping

Discovery of high-level tasks in the operating room

NARCIS (Netherlands)

Bouarfa, L.; Jonker, P.P.; Dankelman, J.

2010-01-01

Recognizing and understanding surgical high-level tasks from sensor readings is important for surgical workflow analysis. Surgical high-level task recognition is also a challenging task in ubiquitous computing because of the inherent uncertainty of sensor data and the complexity of the operating

Methodology for determining void swelling at very high damage under ion irradiation

Energy Technology Data Exchange (ETDEWEB)

Getto, E., E-mail: embecket@umich.edu [Department of Nuclear Engineering and Radiological Sciences, University of Michigan, Ann Arbor, MI 48109 (United States); Sun, K. [Department of Materials Science Engineering, University of Michigan, Ann Arbor, MI 48109 (United States); Taller, S.; Monterrosa, A.M.; Jiao, Z. [Department of Nuclear Engineering and Radiological Sciences, University of Michigan, Ann Arbor, MI 48109 (United States); Was, G.S. [Department of Nuclear Engineering and Radiological Sciences, University of Michigan, Ann Arbor, MI 48109 (United States); Department of Materials Science Engineering, University of Michigan, Ann Arbor, MI 48109 (United States)

2016-08-15

At very high damage levels in ion irradiated samples, the decrease in effective density of the irradiated material due to void swelling can lead to errors in quantifying swelling. HT9 was pre-implanted with 10 appm He and subjected to a raster-scanned beam with a damage rate of ∼1 × 10{sup −3} dpa/s at 460{sup o}C. Voids were characterized from 0 to 1300 nm. Fixed damage rate and fixed depth methods were developed to account for damage-dependent porosity increase and resulting dependence on depth. The fixed depth method was more appropriate as it limits undue effects from the injected interstitial while maintaining a usable void distribution. By keeping the depth fixed and accounting for the change in damage rate due to reduced density, the steady state swelling rate was 10% higher than calculation of swelling from raw data. This method is easily translatable to other materials, ion types and energies and limits the impact of the injected interstitial.

Overview of high-level waste management accomplishments

International Nuclear Information System (INIS)

Lawroski, H.; Berreth, J.R.; Freeby, W.A.

1980-01-01

Storage of power reactor spent fuel is necessary at present because of the lack of reprocessing operations particularly in the U.S. By considering the above solidification and storage scenario, there is more than reasonable assurance that acceptable, stable, low heat generation rate, solidified waste can be produced, and safely disposed. The public perception of no waste disposal solutions is being exploited by detractors of nuclear power application. The inability to even point to one overall system demonstration lends credibility to the negative assertions. By delaying the gathering of on-line information to qualify repository sites, and to implement a demonstration, the actions of the nuclear power detractors are self serving in that they can continue to point out there is no demonstration of satisfactory high-level waste disposal. By maintaining the liquid and solidified high-level waste in secure above ground storage until acceptable decay heat generation rates are achieved, by producing a compatible, high integrity, solid waste form, by providing a second or even third barrier as a compound container and by inserting the enclosed waste form in a qualified repository with spacing to assure moderately low temperature disposal conditions, there appears to be no technical reason for not progressing further with the disposal of high-level wastes and needed implementation of the complete nuclear power fuel cycle

Evaluation of solidified high-level waste forms

International Nuclear Information System (INIS)

1981-01-01

One of the objectives of the IAEA waste management programme is to coordinate and promote development of improved technology for the safe management of radioactive wastes. The Agency accomplished this objective specifically through sponsoring Coordinated Research Programmes on the ''Evaluation of Solidified High Level Waste Products'' in 1977. The primary objectives of this programme are to review and disseminate information on the properties of solidified high-level waste forms, to provide a mechanism for analysis and comparison of results from different institutes, and to help coordinate future plans and actions. This report is a summary compilation of the key information disseminated at the second meeting of this programme

Spent fuel and high-level radioactive waste storage

International Nuclear Information System (INIS)

Trigerman, S.

1988-06-01

The subject of spent fuel and high-level radioactive waste storage, is bibliographically reviewed. The review shows that in the majority of the countries, spent fuels and high-level radioactive wastes are planned to be stored for tens of years. Sites for final disposal of high-level radioactive wastes have not yet been found. A first final disposal facility is expected to come into operation in the United States of America by the year 2010. Other final disposal facilities are expected to come into operation in Germany, Sweden, Switzerland and Japan by the year 2020. Meanwhile , stress is placed upon the 'dry storage' method which is carried out successfully in a number of countries (Britain and France). In the United States of America spent fuels are stored in water pools while the 'dry storage' method is still being investigated. (Author)

Effects of low doses of 14-MeV neutrons on the tensile properties of three binary copper alloys

International Nuclear Information System (INIS)

Heinisch, H.L.; Pintler, J.S.

1986-12-01

Miniature tensile specimens of high purity copper and copper alloyed respectively with five atom percent of Al, Mn, and Ni were irradiated with D-T fusion neutrons in the RTNS-II to fluences up to 1.3 x 10 18 n/cm 2 at 90 0 C. To compare fission and fusion neutron effects, some specimens were also irradiated at the same temperature to similar damage levels in the Omega West Reactor (OWR). Tensile tests were performed at room temperature, and the radiation-induced changes in tensile properties were examined as functions of displacements per atom (dpa). The irradiation-induced strengthening of Cu5%Mn is greater than that of Cu5%Al and Cu5%Ni, which behave about the same. However, all the alloys sustain less irradiation-induced strengthening by 14 MeV neutrons than pure copper, which is in contrast to the reported results of earlier work using hardness measurements. The effects of fission and fusion neutrons on the yield stress of Cu5%Al and Cu5%Ni correlate well on the basis of dpa, but the data for Cu5%Mn suggest that dpa may not be a good correlation parameter for this alloy in this fluence and temperature range

Properties and characteristics of high-level waste glass

International Nuclear Information System (INIS)

Ross, W.A.

1977-01-01

This paper has briefly reviewed many of the characteristics and properties of high-level waste glasses. From this review, it can be noted that glass has many desirable properties for solidification of high-level wastes. The most important of these include: (1) its low leach rate; (2) the ability to tolerate large changes in waste composition; (3) the tolerance of anticipated storage temperatures; (4) its low surface area even after thermal shock or impact

Expression analysis of fiber related genes in cotton (gossypium hirsutum l.) through real time pcr

International Nuclear Information System (INIS)

Iqbal, N.; Khatoon, A.; Asif, M.; Bashir, A.

2016-01-01

Cotton fibers are unicellular seed trichomes and the largest known plant cells. Fiber morphogenesis in cotton is a complex process involving a large number of genes expressed throughout fiber development process. The expression profiling of five gene families in various cotton tissues was carried out through real time PCR. Expression analysis revealed that transcripts of expansin, tubulin and E6 were elevated from 5 to 20 days post anthesis (DPA) fibers. Three Lipid transfer proteins (LTPs) including LTP1, LTP3, LTP7 exhibited highest expression in 10 - 20 DPA fibers. Transcripts of LTP3 were detected in fibers and non fiber tissues that of LTP7 were almost negligible in non fiber tissues. Sucrose phosphate synthase gene showed highest expression in 10 DPA fibers while sucrose synthse (susy) expressed at higher rate in 5-20 DPA fibers as well as roots. The results reveal that most of fiber related genes showed high expression in 5-20 DPA fibers. Comprehensive expression study may help to determine tissue and stage specificity of genes under study. The study may also help to explore complex process of fiber development and understand the role of these genes in fiber development process. Highly expressed genes in fibers may be transformed in cotton for improvement of fiber quality traits. Genes that were expressed specifically in fibers or other tissues could be used for isolation of upstream regulatory sequences. (author)

Stable superconducting magnet. [high current levels below critical temperature

Science.gov (United States)

Boom, R. W. (Inventor)

1967-01-01

Operation of a superconducting magnet is considered. A method is described for; (1) obtaining a relatively high current in a superconducting magnet positioned in a bath of a gas refrigerant; (2) operating a superconducting magnet at a relatively high current level without training; and (3) operating a superconducting magnet containing a plurality of turns of a niobium zirconium wire at a relatively high current level without training.

ALICE High Level Trigger

CERN Multimedia

Alt, T

2013-01-01

The ALICE High Level Trigger (HLT) is a computing farm designed and build for the real-time, online processing of the raw data produced by the ALICE detectors. Events are fully reconstructed from the raw data, analyzed and compressed. The analysis summary together with the compressed data and a trigger decision is sent to the DAQ. In addition the reconstruction of the events allows for on-line monitoring of physical observables and this information is provided to the Data Quality Monitor (DQM). The HLT can process event rates of up to 2 kHz for proton-proton and 200 Hz for Pb-Pb central collisions.

The sleep of elite athletes at sea level and high altitude: a comparison of sea-level natives and high-altitude natives (ISA3600)

Science.gov (United States)

Roach, Gregory D; Schmidt, Walter F; Aughey, Robert J; Bourdon, Pitre C; Soria, Rudy; Claros, Jesus C Jimenez; Garvican-Lewis, Laura A; Buchheit, Martin; Simpson, Ben M; Hammond, Kristal; Kley, Marlen; Wachsmuth, Nadine; Gore, Christopher J; Sargent, Charli

2013-01-01

Background Altitude exposure causes acute sleep disruption in non-athletes, but little is known about its effects in elite athletes. The aim of this study was to examine the effects of altitude on two groups of elite athletes, that is, sea-level natives and high-altitude natives. Methods Sea-level natives were members of the Australian under-17 soccer team (n=14). High-altitude natives were members of a Bolivian under-20 club team (n=12). Teams participated in an 18-day (19 nights) training camp in Bolivia, with 6 nights at near sea level in Santa Cruz (430 m) and 13 nights at high altitude in La Paz (3600 m). Sleep was assessed on every day/night using activity monitors. Results The Australians’ sleep was shorter, and of poorer quality, on the first night at altitude compared with sea level. Sleep quality returned to normal by the end of the first week at altitude, but sleep quantity had still not stabilised at its normal level after 2 weeks. The quantity and quality of sleep obtained by the Bolivians was similar, or greater, on all nights at altitude compared with sea level. The Australians tended to obtain more sleep than the Bolivians at sea level and altitude, but the quality of the Bolivians’ sleep tended to be better than that of the Australians at altitude. Conclusions Exposure to high altitude causes acute and chronic disruption to the sleep of elite athletes who are sea-level natives, but it does not affect the sleep of elite athletes who are high-altitude natives. PMID:24282197

Analysis of Cyberbullying Sensitivity Levels of High School Students and Their Perceived Social Support Levels

Science.gov (United States)

Akturk, Ahmet Oguz

2015-01-01

Purpose: The purpose of this paper is to determine the cyberbullying sensitivity levels of high school students and their perceived social supports levels, and analyze the variables that predict cyberbullying sensitivity. In addition, whether cyberbullying sensitivity levels and social support levels differed according to gender was also…

Microstructural design of PCA austenitic stainless steel for improved resistance to helium embrittlement under HFIR irradiation

International Nuclear Information System (INIS)

Maziasz, P.J.; Braski, D.N.

1983-01-01

Several variants of Prime Candidate Alloy (PCA) with different preirradiation thermal-mechanical treatments were irradiated in HFIR and were evaluated for embrittlement resistance via disk-bend tensile testing. Comparison tests were made on two heats of 20%-cold-worked type 316 stainless steel. None of the alloys were brittle after irradiation at 300 to 400 0 C to approx. 44 dpa and helium levels of 3000 to approx.3600 at. ppm. However, all were quite brittle after similar exposure at 600 0 C. Embrittlement varied with alloy and pretreatment for irradiation to 44 dpa at 500 0 C and to 22 dpa at 600 0 C. Better relative embrittlement resistance among PCA variants was found in alloys which contained prior grain boundary MC carbide particles that remained stable under irradiation

Managing the nation's commercial high-level radioactive waste

International Nuclear Information System (INIS)

1985-03-01

This report presents the findings and conclusions of OTA's analysis of Federal policy for the management of commercial high-level radioactive waste. It represents a major update and expansion of the Analysis presented to Congress in our summary report, Managing Commercial High-Level Radioactive Waste, published in April of 1982 (NWPA). This new report is intended to contribute to the implementation of NWPA, and in particular to Congressional review of three major documents that DOE will submit to the 99th Congress: a Mission Plan for the waste management program; a monitored retrievable storage (MRS) proposal; and a report on mechanisms for financing and managing the waste program. The assessment was originally focused on the ocean disposal of nuclear waste. OTA later broadened the study to include all aspects of high-level waste disposal. The major findings of the original analysis were published in OTA's 1982 summary report

The consequences of helium production on microstructural development in isotopically tailored ferritic alloys

International Nuclear Information System (INIS)

Gelles, D.S.

1996-01-01

A series of alloys have been made adding various isotopes of nickel in order to vary the production of helium during irradiation by a two step nuclear reaction in a mixed spectrum reactor. The alloys use a base composition of Fe-12Cr with an addition of 1.5% nickel, either in the form of 60 Ni which produces no helium, 59 Ni which produces helium at a rate of about 10 appm He/dpa, or natural nickel ( Nat Ni) which provides an intermediate level of helium due to delayed development of 59 Ni. Specimens were irradiated in the HFIR at Oak Ridge, TN to ∼7 dpa at 300 and 400 degrees C. Microstructural examinations indicated that nickel additions promote precipitation in all alloys, but the effect appears to be much stronger at 400 degrees C than at 300 degrees C. There is sufficient dose by 7 dpa (and with 2 appm He) to initiate void swelling in ferritic/martensitic alloys. Little difference was found between response from 59 Ni and Nat Ni. Also, helium bubble development for high helium generation conditions appeared to be very different at 300 and 400 degrees C. At 300 degrees C, it appeared that high densities of bubbles formed whereas at 400 degrees C, bubbles could not be identified, possibly because of the complexity of the microstructure, but more likely because helium accumulated at precipitate interfaces

The consequences of helium production on microstructural development in isotopically tailored ferritic alloys

Energy Technology Data Exchange (ETDEWEB)

Gelles, D.S. [Pacific Northwest Lab., Richland, WA (United States)

1996-10-01

A series of alloys have been made adding various isotopes of nickel in order to vary the production of helium during irradiation by a two step nuclear reaction in a mixed spectrum reactor. The alloys use a base composition of Fe-12Cr with an addition of 1.5% nickel, either in the form of {sup 60}Ni which produces no helium, {sup 59}Ni which produces helium at a rate of about 10 appm He/dpa, or natural nickel ({sup Nat}Ni) which provides an intermediate level of helium due to delayed development of {sup 59}Ni. Specimens were irradiated in the HFIR at Oak Ridge, TN to {approx}7 dpa at 300 and 400{degrees}C. Microstructural examinations indicated that nickel additions promote precipitation in all alloys, but the effect appears to be much stronger at 400{degrees}C than at 300{degrees}C. There is sufficient dose by 7 dpa (and with 2 appm He) to initiate void swelling in ferritic/martensitic alloys. Little difference was found between response from {sup 59}Ni and {sup Nat}Ni. Also, helium bubble development for high helium generation conditions appeared to be very different at 300 and 400{degrees}C. At 300{degrees}C, it appeared that high densities of bubbles formed whereas at 400{degrees}C, bubbles could not be identified, possibly because of the complexity of the microstructure, but more likely because helium accumulated at precipitate interfaces.

Raman spectral titration method: an informative technique for studying the complexation of uranyl with uranyl(vi)-DPA/oxalate systems as examples.

Science.gov (United States)

Liu, Qian; Zhang, Qianci; Yang, Suliang; Zhu, Haiqiao; Liu, Quanwei; Tian, Guoxin

2017-10-10

The Raman band at about 870 cm -1 originating from the symmetric stretch vibration (ν 1 ) of uranyl, UO 2 2+ , has proven to be very informative for investigating the complexation of uranyl using perchlorate or nitrate of known concentration as internal standards. The concentration of uranyl can be conveniently calculated by using the ratio of the directly read band intensities of uranyl and the added reference, ClO 4 - , with a factor of 1.72. While with NO 3 - of concentration lower than 1.8 M as the reference, a factor of 0.85 should be used. Furthermore, with added internal standards, the linear relationship between the Raman intensity and the concentration of the corresponding species is illustrated by the spectral titration of U(vi) with a very strong ligand, dipicolinic acid (DPA); and the application of a spectral titration method with Raman spectroscopy in studying the complexation of uranyl is demonstrated by the titration of U(vi) with oxalate. The stepwise changes in the Raman shift of 18, 17, and 6 cm -1 , corresponding to the three oxalate anions successively bonding to UO 2 2+ , imply that the coordination modes are different. In the 1 : 1 and 1 : 2 ratios of metal to ligand complexes, the oxalate anions bond to the uranyl ion in side-on bidentate mode, but in the 1 : 3 complex the third oxalate bonds in head-on mode, which is much weaker than the first two.

High level cognitive information processing in neural networks

Science.gov (United States)

Barnden, John A.; Fields, Christopher A.

1992-01-01

Two related research efforts were addressed: (1) high-level connectionist cognitive modeling; and (2) local neural circuit modeling. The goals of the first effort were to develop connectionist models of high-level cognitive processes such as problem solving or natural language understanding, and to understand the computational requirements of such models. The goals of the second effort were to develop biologically-realistic model of local neural circuits, and to understand the computational behavior of such models. In keeping with the nature of NASA's Innovative Research Program, all the work conducted under the grant was highly innovative. For instance, the following ideas, all summarized, are contributions to the study of connectionist/neural networks: (1) the temporal-winner-take-all, relative-position encoding, and pattern-similarity association techniques; (2) the importation of logical combinators into connection; (3) the use of analogy-based reasoning as a bridge across the gap between the traditional symbolic paradigm and the connectionist paradigm; and (4) the application of connectionism to the domain of belief representation/reasoning. The work on local neural circuit modeling also departs significantly from the work of related researchers. In particular, its concentration on low-level neural phenomena that could support high-level cognitive processing is unusual within the area of biological local circuit modeling, and also serves to expand the horizons of the artificial neural net field.

The development of summary components for the Disablement in the Physically Active scale in collegiate athletes.

Science.gov (United States)

Houston, Megan N; Hoch, Johanna M; Van Lunen, Bonnie L; Hoch, Matthew C

2015-11-01

The Disablement in the Physically Active scale (DPA) is a generic patient-reported outcome designed to evaluate constructs of disability in physically active populations. The purpose of this study was to analyze the DPA scale structure for summary components. Four hundred and fifty-six collegiate athletes completed a demographic form and the DPA. A principal component analysis (PCA) was conducted with oblique rotation. Factors with eigenvalues >1 that explained >5 % of the variance were retained. The PCA revealed a two-factor structure consistent with paradigms used to develop the original DPA. Items 1-12 loaded on Factors 1 and Items 13-16 loaded on Factor 2. Items 1-12 pertain to impairment, activity limitations, and participation restrictions. Items 13-16 address psychosocial and emotional well-being. Consideration of item content suggested Factor 1 concerned physical function, while Factor 2 concerned mental well-being. Thus, items clustered around Factor 1 and 2 were identified as physical (DPA-PSC) and mental (DPA-MSC) summary components, respectively. Together, the factors accounted for 65.1 % of the variance. The PCA revealed a two-factor structure for the DPA that resulted in DPA-PSC and DPA-MSC. Analyzing the DPA as separate constructs may provide distinct information that could help to prescribe treatment and rehabilitation strategies.

Evaluation of conditioned high-level waste forms

International Nuclear Information System (INIS)

Mendel, J.E.; Turcotte, R.P.; Chikalla, T.D.; Hench, L.L.

1983-01-01

The evaluation of conditioned high-level waste forms requires an understanding of radiation and thermal effects, mechanical properties, volatility, and chemical durability. As a result of nuclear waste research and development programs in many countries, a good understanding of these factors is available for borosilicate glass containing high-level waste. The IAEA through its coordinated research program has contributed to this understanding. Methods used in the evaluation of conditioned high-level waste forms are reviewed. In the US, this evaluation has been facilitated by the definition of standard test methods by the Materials Characterization Center (MCC), which was established by the Department of Energy (DOE) in 1979. The DOE has also established a 20-member Materials Review Board to peer-review the activities of the MCC. In addition to comparing waste forms, testing must be done to evaluate the behavior of waste forms in geologic repositories. Such testing is complex; accelerated tests are required to predict expected behavior for thousands of years. The tests must be multicomponent tests to ensure that all potential interactions between waste form, canister/overpack and corrosion products, backfill, intruding ground water and the repository rock, are accounted for. An overview of the status of such multicomponent testing is presented

High-level waste management technology program plan

Energy Technology Data Exchange (ETDEWEB)

Harmon, H.D.

1995-01-01

The purpose of this plan is to document the integrated technology program plan for the Savannah River Site (SRS) High-Level Waste (HLW) Management System. The mission of the SRS HLW System is to receive and store SRS high-level wastes in a see and environmentally sound, and to convert these wastes into forms suitable for final disposal. These final disposal forms are borosilicate glass to be sent to the Federal Repository, Saltstone grout to be disposed of on site, and treated waste water to be released to the environment via a permitted outfall. Thus, the technology development activities described herein are those activities required to enable successful accomplishment of this mission. The technology program is based on specific needs of the SRS HLW System and organized following the systems engineering level 3 functions. Technology needs for each level 3 function are listed as reference, enhancements, and alternatives. Finally, FY-95 funding, deliverables, and schedules are s in Chapter IV with details on the specific tasks that are funded in FY-95 provided in Appendix A. The information in this report represents the vision of activities as defined at the beginning of the fiscal year. Depending on emergent issues, funding changes, and other factors, programs and milestones may be adjusted during the fiscal year. The FY-95 SRS HLW technology program strongly emphasizes startup support for the Defense Waste Processing Facility and In-Tank Precipitation. Closure of technical issues associated with these operations has been given highest priority. Consequently, efforts on longer term enhancements and alternatives are receiving minimal funding. However, High-Level Waste Management is committed to participation in the national Radioactive Waste Tank Remediation Technology Focus Area. 4 refs., 5 figs., 9 tabs.

High-level waste management technology program plan

International Nuclear Information System (INIS)

Harmon, H.D.

1995-01-01

The purpose of this plan is to document the integrated technology program plan for the Savannah River Site (SRS) High-Level Waste (HLW) Management System. The mission of the SRS HLW System is to receive and store SRS high-level wastes in a see and environmentally sound, and to convert these wastes into forms suitable for final disposal. These final disposal forms are borosilicate glass to be sent to the Federal Repository, Saltstone grout to be disposed of on site, and treated waste water to be released to the environment via a permitted outfall. Thus, the technology development activities described herein are those activities required to enable successful accomplishment of this mission. The technology program is based on specific needs of the SRS HLW System and organized following the systems engineering level 3 functions. Technology needs for each level 3 function are listed as reference, enhancements, and alternatives. Finally, FY-95 funding, deliverables, and schedules are s in Chapter IV with details on the specific tasks that are funded in FY-95 provided in Appendix A. The information in this report represents the vision of activities as defined at the beginning of the fiscal year. Depending on emergent issues, funding changes, and other factors, programs and milestones may be adjusted during the fiscal year. The FY-95 SRS HLW technology program strongly emphasizes startup support for the Defense Waste Processing Facility and In-Tank Precipitation. Closure of technical issues associated with these operations has been given highest priority. Consequently, efforts on longer term enhancements and alternatives are receiving minimal funding. However, High-Level Waste Management is committed to participation in the national Radioactive Waste Tank Remediation Technology Focus Area. 4 refs., 5 figs., 9 tabs

PKA spectrum file

Energy Technology Data Exchange (ETDEWEB)

Kawai, M. [Toshiba Corp., Kawasaki, Kanagawa (Japan). Nuclear Engineering Lab.

1997-03-01

In the Japanese Nuclear Data Committee, the PKA/KERMA file containing PKA spectra, KERMA factors and DPA cross sections in the energy range between 10{sup -5} eV and 50 MeV is being prepared from the evaluated nuclear data. The processing code ESPERANT was developed to calculate quantities of PKA, KERMA and DPA from evaluated nuclear data for medium and heavy elements by using the effective single particle emission approximation (ESPEA). For light elements, the PKA spectra are evaluated by the SCINFUL/DDX and EXIFON codes, simultaneously with other neutron cross sections. The DPA cross sections due to charged particle emitted from light elements are evaluated for high neutron energy above 20 MeV. (author)

Department of Energy pretreatment of high-level and low-level wastes

International Nuclear Information System (INIS)

McGinnis, C.P.; Hunt, R.D.

1995-01-01

The remediation of the 1 x 10 8 gal of highly radioactive waste in the underground storage tanks (USTs) at five US Department of Energy (DOE) sites is one of DOE's greatest challenges. Therefore, the DOE Office of Environmental Management has created the Tank Focus Area (TFA) to manage an integrated technology development program that results in the safe and efficient remediation of UST waste. The TFA has divided its efforts into five areas, which are safety, characterization, retrieval/closure, pretreatment, and immobilization. All DOE pretreatment activities are integrated by the Pretreatment Technical Integration Manager of the TFA. For FY 1996, the 14 pretreatment tasks are divided into 3 systems: supernate separations, sludge treatment, and solid/liquid separation. The plans and recent results of these TFA tasks, which include two 25,000-gal demonstrations and two former TFA tasks on Cs removal, are presented. The pretreatment goals are to minimize the volume of high-level waste and the radioactivity in low-level waste

High level radioactive wastes: Considerations on final disposal

International Nuclear Information System (INIS)

Ciallella, Norberto R.

2000-01-01

When at the beginnings of the decade of the 80 the National Commission on Atomic Energy (CNEA) in Argentina decided to study the destination of the high level radioactive wastes, was began many investigations, analysis and multidisciplinary evaluations that be origin to a study of characteristics never before carried out in Argentina. For the first time in the country was faced the study of an environmental eventual problem, several decades before that the problem was presented. The elimination of the high level radioactive wastes in the technological aspects was taken in advance, avoiding to transfer the problems to the future generations. The decision was based, not only in technical evaluations but also in ethical premises, since it was considered that the future generations may enjoy the benefits of the nuclear energy and not should be solve the problem. The CNEA in Argentina in 1980 decided to begin a feasibility study and preliminary engineering project for the construction of the final disposal of high level radioactive wastes

Techniques for the solidification of high-level wastes

International Nuclear Information System (INIS)

1977-01-01

The problem of the long-term management of the high-level wastes from the reprocessing of irradiated nuclear fuel is receiving world-wide attention. While the majority of the waste solutions from the reprocessing of commercial fuels are currently being stored in stainless-steel tanks, increasing effort is being devoted to developing technology for the conversion of these wastes into solids. A number of full-scale solidification facilities are expected to come into operation in the next decade. The object of this report is to survey and compare all the work currently in progress on the techniques available for the solidification of high-level wastes. It will examine the high-level liquid wastes arising from the various processes currently under development or in operation, the advantages and disadvantages of each process for different types and quantities of waste solutions, the stages of development, the scale-up potential and flexibility of the processes

Transmission Level High Temperature Superconducting Fault Current Limiter

Energy Technology Data Exchange (ETDEWEB)

Stewart, Gary [SuperPower, Inc., Schenectady, NY (United States)

2016-10-05

The primary objective of this project was to demonstrate the feasibility and reliability of utilizing high-temperature superconducting (HTS) materials in a Transmission Level Superconducting Fault Current Limiter (SFCL) application. During the project, the type of high-temperature superconducting material used evolved from 1^st generation (1G) BSCCO-2212 melt cast bulk high-temperature superconductors to 2^nd generation (2G) YBCO-based high-temperature superconducting tape. The SFCL employed SuperPower's “Matrix” technology, that offers modular features to enable scale up to transmission voltage levels. The SFCL consists of individual modules that contain elements and parallel inductors that assist in carrying the current during the fault. A number of these modules are arranged in an m x n array to form the current-limiting matrix.

Materials for high-level waste containment

International Nuclear Information System (INIS)

Marsh, G.P.

1982-01-01

The function of the high-level radioactive waste container in storage and of a container/overpack combination in disposal is considered. The consequent properties required from potential fabrication materials are discussed. The strategy adopted in selecting containment materials and the experimental programme underway to evaluate them are described. (U.K.)

Psilocybin impairs high-level but not low-level motion perception.

Science.gov (United States)

Carter, Olivia L; Pettigrew, John D; Burr, David C; Alais, David; Hasler, Felix; Vollenweider, Franz X

2004-08-26

The hallucinogenic serotonin(1A&2A) agonist psilocybin is known for its ability to induce illusions of motion in otherwise stationary objects or textured surfaces. This study investigated the effect of psilocybin on local and global motion processing in nine human volunteers. Using a forced choice direction of motion discrimination task we show that psilocybin selectively impairs coherence sensitivity for random dot patterns, likely mediated by high-level global motion detectors, but not contrast sensitivity for drifting gratings, believed to be mediated by low-level detectors. These results are in line with those observed within schizophrenic populations and are discussed in respect to the proposition that psilocybin may provide a model to investigate clinical psychosis and the pharmacological underpinnings of visual perception in normal populations.

Approximate Bisimulation for High-Level Datapaths in Intelligent Transportation Systems

Directory of Open Access Journals (Sweden)

Hui Deng

2013-01-01

Full Text Available A relation called approximate bisimulation is proposed to achieve behavior and structure optimization for a type of high-level datapath whose data exchange processes are expressed by nonlinear polynomial systems. The high-level datapaths are divided into small blocks with a partitioning method and then represented by polynomial transition systems. A standardized form based on Ritt-Wu's method is developed to represent the equivalence relation for the high-level datapaths. Furthermore, we establish an approximate bisimulation relation within a controllable error range and express the approximation with an error control function, which is processed by Sostools. Meanwhile, the error is controlled through tuning the equivalence restrictions. An example of high-level datapaths demonstrates the efficiency of our method.

High-Level Waste (HLW) Feed Process Control Strategy

International Nuclear Information System (INIS)

STAEHR, T.W.

2000-01-01

The primary purpose of this document is to describe the overall process control strategy for monitoring and controlling the functions associated with the Phase 1B high-level waste feed delivery. This document provides the basis for process monitoring and control functions and requirements needed throughput the double-shell tank system during Phase 1 high-level waste feed delivery. This document is intended to be used by (1) the developers of the future Process Control Plan and (2) the developers of the monitoring and control system

Treatment technologies for non-high-level wastes (USA)

International Nuclear Information System (INIS)

Cooley, C.R.; Clark, D.E.

1976-06-01

Non-high-level waste arising from operations at nuclear reactors, fuel fabrication facilities, and reprocessing facilities can be treated using one of several technical alternatives prior to storage. Each alternative and the associated experience and status of development are summarized. The technology for treating non-high-level wastes is generally available for industrial use. Improved techniques applicable to the commercial nuclear fuel cycle are being developed and demonstrated to reduce the volume of waste and to immobilize it for storage. 36 figures, 59 references

Removing high-level contaminants

International Nuclear Information System (INIS)

Wallace, Paula

2013-01-01

Full text: Using biomimicry, an Australian cleantech innovation making inroads intoChinas's industrial sector offers multiple benefits to miners and processors in Australia. Stephen Shelley, the executive chairman of Creative Water Technology (CWT), was on hand at a recent trade show to explain how his Melbourne company has developed world-class techniques in zero liquid discharge and fractional crystallization of minerals to apply to a wide range of water treatment and recycling applications. “Most existing technologies operate with high energy distillation, filters or biological processing. CWT's appliance uses a low temperature, thermal distillation process known as adiabatic recovery to desalinate, dewater and/or recycle highly saline and highly contaminated waste water,” said Shelley. The technology has been specifically designed to handle the high levels of contaminant that alternative technologies struggle to process, with proven water quality results for feed water samples with TDS levels over 300,000ppm converted to clean water with less than 20ppm. Comparatively, reverse osmosis struggles to process contaminant levels over 70,000ppm effectively. “CWT is able to reclaim up to 97% clean usable water and up to 100% of the contaminants contained in the feed water,” said Shelley, adding that soluble and insoluble contaminants are separately extracted and dried for sale or re-use. In industrial applications CWT has successfully processed feed water with contaminant levels over 650,000 mg/1- without the use of chemicals. “The technology would be suitable for companies in oil exploration and production, mining, smelting, biofuels, textiles and the agricultural and food production sectors,” said Shelley. When compared to a conventional desalination plant, the CWT system is able to capture the value in the brine that most plants discard, not only from the salt but the additional water it contains. “If you recover those two commodities... then you

Influence of Silicon on Swelling and Microstructure in Russian Austenitic Stainless Steels Irradiated to High Neutron Doses

International Nuclear Information System (INIS)

Porollo, S.I.; Shulepin, S.V.; Konobeev, Y.V.; Garner, F.

2007-01-01

Full text of publication follows: For some applications in fusion devices austenitic stainless steels are still considered to be candidates for use as structural components, but high neutron exposures must be endured by the steels. Operational experience of fast reactors in Western Europe, USA and Japan provides evidence of the possible use of austenitic steels up to ∼ 150 dpa. Studies aimed at improvement of existing Russian austenitic steels are being carried out in Russia. For improvement of irradiation resistance of Russian steels it is necessary to understand the basic mechanisms responsible for deterioration of steel properties. This understanding can be achieved by continuing detailed investigations of the microstructure of cladding steels after irradiation to high doses. By investigating the evolution of radiation-induced microstructure in neutron irradiated steels of different chemical composition one can study the effect of chemical variations on steel properties. Silicon is one of the most important chemical elements that strongly influence the behavior of austenitic steel properties under irradiation. In this paper results are presented of investigations of the effect of silicon additions on void swelling and microstructure of base austenitic stainless steel EI-847 (0.06C-16Cr-15Ni- 3Mo-Nb) irradiated as fuel pin cladding of both regular and experimental assemblies in the BOR-60, BN-350 and BN-600 fast reactors to neutron doses up to 49 dpa. The possible mechanisms of silicon's effect on void swelling in austenitic stainless steels are presented and analyzed. (authors)

Elevated level of polysaccharides in a high level UV-B tolerant cell ...

African Journals Online (AJOL)

Jane

2011-04-26

Apr 26, 2011 ... A cell line of Bupleurum scorzonerifolium Willd with high level ... mechanisms to repair UV-induced damages via repairing ... for treatment or prevention of solar radiation. ..... working as both UV-B absorbing compounds and.

Heroin purchasing is income and price sensitive.

Science.gov (United States)

Roddy, Juliette; Steinmiller, Caren L; Greenwald, Mark K

2011-06-01

Semi-structured interviews were used to assess behavioral economic drug demand in heroin dependent research volunteers. Findings on drug price, competing purchases, and past 30-day income and consumption, established in a previous study, are replicated. We extended these findings by having participants indicate whether hypothetical environmental changes would alter heroin purchasing. Participants (n = 109) reported they would significantly (p purchasing amounts (DPA) from past 30-day levels (M = $60/day) if: (a) they encountered a 33% decrease in income (DPA = $34), (b) family/friends no longer paid their living expenses (DPA = $32), or (c) they faced four-fold greater likelihood of police arrest at their purchasing location (DPA = $42). Participants in higher income quartiles (who purchase more heroin) show greater DPA reductions (but would still buy more heroin) than those in lower income quartiles. For participants receiving government aid (n = 31), heroin purchasing would decrease if those subsidies were eliminated (DPA = $28). Compared to participants whose urine tested negative for cocaine (n = 31), cocaine-positive subjects (n = 32) reported more efficient heroin purchasing, that is, they live closer to their primary dealer; are more likely to have heroin delivered or walk to obtain it (and less likely to ride the bus), thus reducing purchasing time (52 vs. 31 min, respectively); and purchase more heroin per episode. These simulation results have treatment and policy implications: Daily heroin users' purchasing repertoire is very cost-effective, more so for those also using cocaine, and only potent environmental changes (income reductions or increased legal sanctions) may impact this behavior. (PsycINFO Database Record (c) 2011 APA, all rights reserved).

Python based high-level synthesis compiler

Science.gov (United States)

Cieszewski, Radosław; Pozniak, Krzysztof; Romaniuk, Ryszard

2014-11-01

This paper presents a python based High-Level synthesis (HLS) compiler. The compiler interprets an algorithmic description of a desired behavior written in Python and map it to VHDL. FPGA combines many benefits of both software and ASIC implementations. Like software, the mapped circuit is flexible, and can be reconfigured over the lifetime of the system. FPGAs therefore have the potential to achieve far greater performance than software as a result of bypassing the fetch-decode-execute operations of traditional processors, and possibly exploiting a greater level of parallelism. Creating parallel programs implemented in FPGAs is not trivial. This article describes design, implementation and first results of created Python based compiler.

Aeon: Synthesizing Scheduling Algorithms from High-Level Models

Science.gov (United States)

Monette, Jean-Noël; Deville, Yves; van Hentenryck, Pascal

This paper describes the aeon system whose aim is to synthesize scheduling algorithms from high-level models. A eon, which is entirely written in comet, receives as input a high-level model for a scheduling application which is then analyzed to generate a dedicated scheduling algorithm exploiting the structure of the model. A eon provides a variety of synthesizers for generating complete or heuristic algorithms. Moreover, synthesizers are compositional, making it possible to generate complex hybrid algorithms naturally. Preliminary experimental results indicate that this approach may be competitive with state-of-the-art search algorithms.

Fracture toughness of neutron irradiated solid and powder HIP 316L(N). ITER Task 214, NET deliverable GB6 ECN-5

International Nuclear Information System (INIS)

Rensman, J.; Van den Broek, F.P.; Jong, M.; Van Osch, E.V.

1998-04-01

The fracture toughness properties of unirradiated and neutron irradiated type 316L(N) stainless steel plate (European Reference Heat ERHII), conventional 316L(N) solid HIP joints (heat PM-130), and 316L(N)-1G powder HIP material have been measured. Compact tension specimens with a thickness of 12 and 5 mm were irradiated in the High Flux Reactor (HFR) in Petten, The Netherlands, simulating the fusion reactor's first wall conditions by a combination of high displacement damage with proportional amounts of helium. The solid HIP (or HIP-bonded) CT-specimens were irradiated in two separate experiments: SIWAS-6 with 1.3 to 2.3 dpa (1.7 dpa av.) at 353 K, and CHARIOT-3 with 2.7 to 3.1 dpa (2.9 dpa av.) at 600 K. The plate material and powder HIP CT-specimens were irradiated in one experiment only, SIWAS-6. The helium content is up to 20 appm for the 2.9 dpa (av.) dose level. Testing temperatures of 353K and 573K have been used for the fracture toughness experiments. The report contains the experimental conditions and summarises the results, which are given in terms of J-resistance curve fits. The main conclusions are that all three materials have very high toughness in the unirradiated state with little difference between them; the solid HIP has the highest toughness, the powder HIP lowest. The toughness of all three materials is reduced significantly by irradiation, the reduction is the least for the plate material and the highest for the powder HIP material. However, many, but not all, of the solid HIP CT specimens showed debonding of the joint during testing. The machined notch of the CT specimens was not exactly on the joint interface, which could lead to unjustified interpretation of the measured values as being the toughness of the joint, the toughness of the joint being probably much lower. The reduction by irradiation of the fracture toughness of the powder HIP material is clearly larger than for plate material, which is confirmed by the observed early initiation

Technetium Chemistry in High-Level Waste

International Nuclear Information System (INIS)

Hess, Nancy J.

2006-01-01

Tc contamination is found within the DOE complex at those sites whose mission involved extraction of plutonium from irradiated uranium fuel or isotopic enrichment of uranium. At the Hanford Site, chemical separations and extraction processes generated large amounts of high level and transuranic wastes that are currently stored in underground tanks. The waste from these extraction processes is currently stored in underground High Level Waste (HLW) tanks. However, the chemistry of the HLW in any given tank is greatly complicated by repeated efforts to reduce volume and recover isotopes. These processes ultimately resulted in mixing of waste streams from different processes. As a result, the chemistry and the fate of Tc in HLW tanks are not well understood. This lack of understanding has been made evident in the failed efforts to leach Tc from sludge and to remove Tc from supernatants prior to immobilization. Although recent interest in Tc chemistry has shifted from pretreatment chemistry to waste residuals, both needs are served by a fundamental understanding of Tc chemistry

Handbook of high-level radioactive waste transportation

International Nuclear Information System (INIS)

Sattler, L.R.

1992-10-01

The High-Level Radioactive Waste Transportation Handbook serves as a reference to which state officials and members of the general public may turn for information on radioactive waste transportation and on the federal government's system for transporting this waste under the Civilian Radioactive Waste Management Program. The Handbook condenses and updates information contained in the Midwestern High-Level Radioactive Waste Transportation Primer. It is intended primarily to assist legislators who, in the future, may be called upon to enact legislation pertaining to the transportation of radioactive waste through their jurisdictions. The Handbook is divided into two sections. The first section places the federal government's program for transporting radioactive waste in context. It provides background information on nuclear waste production in the United States and traces the emergence of federal policy for disposing of radioactive waste. The second section covers the history of radioactive waste transportation; summarizes major pieces of legislation pertaining to the transportation of radioactive waste; and provides an overview of the radioactive waste transportation program developed by the US Department of Energy (DOE). To supplement this information, a summary of pertinent federal and state legislation and a glossary of terms are included as appendices, as is a list of publications produced by the Midwestern Office of The Council of State Governments (CSG-MW) as part of the Midwestern High-Level Radioactive Waste Transportation Project

Development of oxide dispersion strengthened 9Cr ferritic-martensitic steel clad tube for fast reactor

International Nuclear Information System (INIS)

Laha, K.; Saroja, S.; Mathew, M.D.; Jayakumar, T.; Vijay, R.; Venugopal Reddy, A.; Lakshminarayana, B.; Kapoor, Komal; Jha, S.K.; Tonpe, S.S.

2012-01-01

One of the key issues in the economical operation of FBR is to achieve high burn-up of fuel (200-250 GWd/t) which considerably reduces the fuel cycle cost. This imposes stringent requirements of void swelling resistance upto 200 dpa for the core structural materials. Presently used alloy 09 (a modified austenitic stainless steel, 15Cr-15Ni-Ti) for PFBR has void swelling limit less than 150 dpa. Because of the inherent void swelling resistance, 9-12Cr steels ferritic/martensitic steels are qualified for irradiation upto 200 dpa but their low creep strength at temperatures above 600 deg C restricts their application as a clad material. Oxide dispersion strengthening is found to be promising means of extending the creep resistance of ferritic/martensitic steels beyond 650 deg C without sacrificing the inherent advantages of high thermal conductivity and low swelling of ferritic steels

High-Throughput Automatic Training System for Odor-Based Learned Behaviors in Head-Fixed Mice

Directory of Open Access Journals (Sweden)

Zhe Han

2018-02-01

Full Text Available Understanding neuronal mechanisms of learned behaviors requires efficient behavioral assays. We designed a high-throughput automatic training system (HATS for olfactory behaviors in head-fixed mice. The hardware and software were constructed to enable automatic training with minimal human intervention. The integrated system was composed of customized 3D-printing supporting components, an odor-delivery unit with fast response, Arduino based hardware-controlling and data-acquisition unit. Furthermore, the customized software was designed to enable automatic training in all training phases, including lick-teaching, shaping and learning. Using HATS, we trained mice to perform delayed non-match to sample (DNMS, delayed paired association (DPA, Go/No-go (GNG, and GNG reversal tasks. These tasks probed cognitive functions including sensory discrimination, working memory, decision making and cognitive flexibility. Mice reached stable levels of performance within several days in the tasks. HATS enabled an experimenter to train eight mice simultaneously, therefore greatly enhanced the experimental efficiency. Combined with causal perturbation and activity recording techniques, HATS can greatly facilitate our understanding of the neural-circuitry mechanisms underlying learned behaviors.

High estradiol levels improve false memory rates and meta-memory in highly schizotypal women.

Science.gov (United States)

Hodgetts, Sophie; Hausmann, Markus; Weis, Susanne

2015-10-30

Overconfidence in false memories is often found in patients with schizophrenia and healthy participants with high levels of schizotypy, indicating an impairment of meta-cognition within the memory domain. In general, cognitive control is suggested to be modulated by natural fluctuations in oestrogen. However, whether oestrogen exerts beneficial effects on meta-memory has not yet been investigated. The present study sought to provide evidence that high levels of schizotypy are associated with increased false memory rates and overconfidence in false memories, and that these processes may be modulated by natural differences in estradiol levels. Using the Deese-Roediger-McDermott paradigm, it was found that highly schizotypal participants with high estradiol produced significantly fewer false memories than those with low estradiol. No such difference was found within the low schizotypy participants. Highly schizotypal participants with high estradiol were also less confident in their false memories than those with low estradiol; low schizotypy participants with high estradiol were more confident. However, these differences only approached significance. These findings suggest that the beneficial effect of estradiol on memory and meta-memory observed in healthy participants is specific to highly schizotypal individuals and might be related to individual differences in baseline dopaminergic activity. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Generation of Efficient High-Level Hardware Code from Dataflow Programs

OpenAIRE

Siret , Nicolas; Wipliez , Matthieu; Nezan , Jean François; Palumbo , Francesca

2012-01-01

High-level synthesis (HLS) aims at reducing the time-to-market by providing an automated design process that interprets and compiles high-level abstraction programs into hardware. However, HLS tools still face limitations regarding the performance of the generated code, due to the difficulties of compiling input imperative languages into efficient hardware code. Moreover the hardware code generated by the HLS tools is usually target-dependant and at a low level of abstraction (i.e. gate-level...

Omega-3 Fatty Acids and Incident Ischemic Stroke and Its Atherothrombotic and Cardioembolic Subtypes in 3 US Cohorts.

Science.gov (United States)

Saber, Hamidreza; Yakoob, Mohammad Yawar; Shi, Peilin; Longstreth, W T; Lemaitre, Rozenn N; Siscovick, David; Rexrode, Kathryn M; Willett, Walter C; Mozaffarian, Dariush

2017-10-01

The associations of individual long-chain n-3 polyunsaturated fatty acids with incident ischemic stroke and its main subtypes are not well established. We aimed to investigate prospectively the relationship of circulating eicosapentaenoic acid, docosapentaenoic acid (DPA), and docosahexaenoic acid (DHA) with risk of total ischemic, atherothrombotic, and cardioembolic stroke. We measured circulating phospholipid fatty acids at baseline in 3 separate US cohorts: CHS (Cardiovascular Health Study), NHS (Nurses' Health Study), and HPFS (Health Professionals Follow-Up Study). Ischemic strokes were prospectively adjudicated and classified into atherothrombotic (large- and small-vessel infarctions) or cardioembolic by imaging studies and medical records. Risk according to fatty acid levels was assessed using Cox proportional hazards (CHS) or conditional logistic regression (NHS, HPFS) according to study design. Cohort findings were pooled using fixed-effects meta-analysis. A total of 953 incident ischemic strokes were identified (408 atherothrombotic, 256 cardioembolic, and 289 undetermined subtypes) during median follow-up of 11.2 years (CHS) and 8.3 years (pooled, NHS and HPFS). After multivariable adjustment, lower risk of total ischemic stroke was seen with higher DPA (highest versus lowest quartiles; pooled hazard ratio [HR], 0.74; 95% confidence interval [CI], 0.58-0.92) and DHA (HR, 0.80; 95% CI, 0.64-1.00) but not eicosapentaenoic acid (HR, 0.94; 95% CI, 0.77-1.19). DHA was associated with lower risk of atherothrombotic stroke (HR, 0.53; 95% CI, 0.34-0.83) and DPA with lower risk of cardioembolic stroke (HR, 0.58; 95% CI, 0.37-0.92). Findings in each individual cohort were consistent with pooled results. In 3 large US cohorts, higher circulating levels of DHA were inversely associated with incident atherothrombotic stroke and DPA with cardioembolic stroke. These novel findings suggest differential pathways of benefit for DHA, DPA, and eicosapentaenoic acid. © 2017

Serum osteoprotegerin levels and mammographic density among high-risk women.

Science.gov (United States)

Moran, Olivia; Zaman, Tasnim; Eisen, Andrea; Demsky, Rochelle; Blackmore, Kristina; Knight, Julia A; Elser, Christine; Ginsburg, Ophira; Zbuk, Kevin; Yaffe, Martin; Narod, Steven A; Salmena, Leonardo; Kotsopoulos, Joanne

2018-06-01

Mammographic density is a risk factor for breast cancer but the mechanism behind this association is unclear. The receptor activator of nuclear factor κB (RANK)/RANK ligand (RANKL) pathway has been implicated in the development of breast cancer. Given the role of RANK signaling in mammary epithelial cell proliferation, we hypothesized this pathway may also be associated with mammographic density. Osteoprotegerin (OPG), a decoy receptor for RANKL, is known to inhibit RANK signaling. Thus, it is of interest to evaluate whether OPG levels modify breast cancer risk through mammographic density. We quantified serum OPG levels in 57 premenopausal and 43 postmenopausal women using an enzyme-linked immunosorbent assay (ELISA). Cumulus was used to measure percent density, dense area, and non-dense area for each mammographic image. Subjects were classified into high versus low OPG levels based on the median serum OPG level in the entire cohort (115.1 pg/mL). Multivariate models were used to assess the relationship between serum OPG levels and the measures of mammographic density. Serum OPG levels were not associated with mammographic density among premenopausal women (P ≥ 0.42). Among postmenopausal women, those with low serum OPG levels had higher mean percent mammographic density (20.9% vs. 13.7%; P = 0.04) and mean dense area (23.4 cm 2 vs. 15.2 cm 2 ; P = 0.02) compared to those with high serum OPG levels after covariate adjustment. These findings suggest that low OPG levels may be associated with high mammographic density, particularly in postmenopausal women. Targeting RANK signaling may represent a plausible, non-surgical prevention option for high-risk women with high mammographic density, especially those with low circulating OPG levels.

Microstructure and mechanical properties of FeCrAl alloys under heavy ion irradiations

Science.gov (United States)

Aydogan, E.; Weaver, J. S.; Maloy, S. A.; El-Atwani, O.; Wang, Y. Q.; Mara, N. A.

2018-05-01

FeCrAl ferritic alloys are excellent cladding candidates for accident tolerant fuel systems due to their high resistance to oxidation as a result of formation of a protective Al2O3 scale at high temperatures in steam. In this study, we report the irradiation response of the 10Cr and 13Cr FeCrAl cladding tubes under Fe2+ ion irradiation up to ∼16 dpa at 300 °C. Dislocation loop size, density and characteristics were determined using both two-beam bright field transmission electron microscopy and on-zone scanning transmission electron microscopy techniques. 10Cr (C06M2) tube has a lower dislocation density, larger grain size and a slightly weaker texture compared to the 13Cr (C36M3) tube before irradiation. After irradiation to 0.7 dpa and 16 dpa, the fraction of type sessile dislocations decreases with increasing Cr amount in the alloys. It has been found that there is neither void formation nor α‧ precipitation as a result of ion irradiations in either alloy. Therefore, dislocation loops were determined to be the only irradiation induced defects contributing to the hardening. Nanoindentation testing before the irradiation revealed that the average nanohardness of the C36M3 tube is higher than that of the C06M2 tube. The average nanohardness of irradiated tube samples saturated at 1.6-2.0 GPa hardening for both tubes between ∼3.4 dpa and ∼16 dpa. The hardening calculated based on transmission electron microscopy was found to be consistent with nanohardness measurements.

Materials Science of High-Level Nuclear Waste Immobilization

International Nuclear Information System (INIS)

Weber, William J.; Navrotsky, Alexandra; Stefanovsky, S. V.; Vance, E. R.; Vernaz, Etienne Y.

2009-01-01

With the increasing demand for the development of more nuclear power comes the responsibility to address the technical challenges of immobilizing high-level nuclear wastes in stable solid forms for interim storage or disposition in geologic repositories. The immobilization of high-level nuclear wastes has been an active area of research and development for over 50 years. Borosilicate glasses and complex ceramic composites have been developed to meet many technical challenges and current needs, although regulatory issues, which vary widely from country to country, have yet to be resolved. Cooperative international programs to develop advanced proliferation-resistant nuclear technologies to close the nuclear fuel cycle and increase the efficiency of nuclear energy production might create new separation waste streams that could demand new concepts and materials for nuclear waste immobilization. This article reviews the current state-of-the-art understanding regarding the materials science of glasses and ceramics for the immobilization of high-level nuclear waste and excess nuclear materials and discusses approaches to address new waste streams

The immobilization of High Level Waste Into Glass

International Nuclear Information System (INIS)

Aisyah; Martono, H.

1998-01-01

High level liquid waste is generated from the first step extraction in the nuclear fuel reprocessing. The waste is immobilized with boro-silicate glass. A certain composition of glass is needed for a certain type of waste, so that the properties of waste glass would meet the requirement either for further process or for disposal. The effect of waste loading on either density, thermal expansion, softening point and leaching rate has been studied. The composition of the high level liquid waste has been determined by ORIGEN 2 and the result has been used to prepare simulated high level waste. The waste loading in the waste glass has been set to be 19.48; 22.32; 25.27; and 26.59 weight percent. The result shows that increasing the waste loading has resulted in the higher density with no thermal expansion and softening point significant change. The increase in the waste loading increase that leaching rate. The properties of the waste glass in this research have not shown any deviation from the standard waste glass properties

A New Approach of Parallelism and Load Balance for the Apriori Algorithm

Directory of Open Access Journals (Sweden)

BOLINA, A. C.

2013-06-01

Full Text Available The main goal of data mining is to discover relevant information on digital content. The Apriori algorithm is widely used to this objective, but its sequential version has a low performance when execu- ted over large volumes of data. Among the solutions for this problem is the parallel implementation of the algorithm, and among the parallel implementations presented in the literature that based on Apriori, it highlights the DPA (Distributed Parallel Apriori [10]. This paper presents the DMTA (Distributed Multithread Apriori algorithm, which is based on DPA and exploits the parallelism level of threads in order to increase the performance. Besides, DMTA can be executed over heterogeneous hardware platform, using different number of cores. The results showed that DMTA outperforms DPA, presents load balance among processes and threads, and it is effective in current multicore architectures.

ONDRAF/NIRAS and high-level radioactive waste management in Belgium

International Nuclear Information System (INIS)

Decamps, F.

1993-01-01

The National Agency for Radioactive Waste and Enriched Fissile Materials, ONDRAF/NIRAS, is a public body with legal personality in charge of managing all radioactive waste on Belgian territory, regardless of its origin and source. It is also entrusted with tasks related to the management of enriched fissile materials, plutonium containing materials and used or unused nuclear fuel, and with certain aspects of the dismantling of closed down nuclear facilities. High-level radioactive waste management comprises essentially and for the time being the storage of high-level liquid waste produced by the former EUROCHEMIC reprocessing plant and of high-level and very high-level heat producing waste resulting from the reprocessing in France of Belgian spent fuel, as well as research and development (R and D) with regard to geological disposal in clay of this waste type

Hanford long-term high-level waste management program overview

International Nuclear Information System (INIS)

Reep, I.E.

1978-05-01

The objective is the long-term disposition of the defense high-level radioactive waste which will remain upon completion of the interim waste management program in the mid-1980s, plus any additional high-level defense waste resulting from the future operation of N Reactor and the Purex Plant. The high-level radioactive waste which will exist in the mid-1980s and is addressed by this plan consists of approximately 3,300,000 ft 3 of damp salt cake stored in single-shell and double-shell waste tanks, 1,500,000 ft 3 of damp sludge stored in single-shell and double-shell waste tanks, 11,000,000 gallons of residual liquor stored in double-shell waste tanks, 3,000,000 gallons of liquid wastes stored in double-shell waste tanks awaiting solidification, and 2,900 capsules of 90 SR and 137 Cs compounds stored in water basins. Final quantities of waste may be 5 to 10% greater, depending on the future operation of N Reactor and the Purex Plant and the application of waste treatment techniques currently under study to reduce the inventory of residual liquor. In this report, the high-level radioactive waste addressed by this plan is briefly described, the major alternatives and strategies for long-term waste management are discussed, and a description of the long-term high-level waste management program is presented. Separate plans are being prepared for the long-term management of radioactive wastes which exist in other forms. 14 figures

Two-dimensional coordination polymer matrix for solid-phase extraction of pesticide residues from plant Cordia salicifolia.

Science.gov (United States)

de Carvalho, Pedro Henrique Viana; Barreto, Alysson Santos; Rodrigues, Marcelo O; Prata, Vanessa de Menezes; Alves, Péricles Barreto; de Mesquita, Maria Eliane; Alves, Severino; Navickiene, Sandro

2009-06-01

The 2D coordination polymer (infinity[Gd(DPA)(HDPA)]) was tested for extraction of acephate, chlorpropham, pirimicarb, bifenthrin, tetradifon, and phosalone from the medicinal plant Cordia salicifolia, whose extracts are commercialized in Brazil as diuretic, appetite suppressant, and weight loss products, using GC/MS, SIM. Considering that there are no Brazilian regulations concerning maximum permissible pesticide residue concentrations in medicinal herbs, recovery experiments were carried out (seven replicates), at two arbitrary fortification levels (0.5 and 1.0 mg/kg), resulting in recoveries in range of 20 to 107.7% and SDRSDs were between 5.6 and 29.1% for infinity[Gd(DPA)(HDPA)] sorbent. Detection and quantification limits for herb ranged from 0.10 to 0.15 mg/kg and from 0.15 to 0.25 mg/kg, respectively, for the different pesticides studied. The developed method is linear over the range assayed, 0.5-10.0 microg/mL, with correlation coefficients ranging from 0.9975 to 0.9986 for all pesticides. Comparison between infinity[Gd(DPA)(HDPA)] sorbent and conventional sorbent (neutral alumina) showed similar performance of infinity[Gd(DPA)(HDPA)] polymeric sorbent for three (bifenthrin, tetradifon, and phosalone) out of six pesticides tested.

TEM examination of the effect of post-irradiation annealing on 7.7 dpa AISI 304 stainless steel

International Nuclear Information System (INIS)

Karlsen, W.; Ivanchenko, M.; Pakarinen, J.; Karlsen, T.

2015-01-01

Stainless steels exposed to neutron irradiation during service in light water reactors (LWR) can become susceptible to intergranular cracking, referred to as irradiation assisted stress corrosion cracking (IASCC). Analytical transmission electron microscopy (ATEM) was used to examine the effect of post-irradiation annealing (PIA) on radiation-induced segregation (RIS) at the grain boundaries of 7.7 dpa AISI 304 stainless steel. The grain boundary profiles and the irradiation damage were analysed in the as-irradiated state and after PIA of 6 hours at 500 C. degrees and after 25 hours at 500 C. degrees and 550 C. degrees by using transmission electron microscopy (TEM). As a main conclusion from the TEM examinations, the effects of PIA were found to be relatively small after only 6 hours, while after 25 hours of PIA at both 500 and 550 C. degrees, RIS was almost recovered and only marginal deviation in chemical composition could be found near the GB. The as-irradiated state showed extreme RIS values of Si 4.9 wt%, Cr 14.7 wt%, Ni 23.4 wt%, and P 1.4 wt%., while upon PIA for 6 hours the extreme values for RIS were Si 3.9 wt%, Cr 16.0 wt%, Ni 21 wt%, and P 0.9 wt%. After 6 hours annealing at 500 C. dislocation loops start to grow, while dislocation density remains of the same order of magnitude. After annealing for 25 hours at 500 C. degrees the average size of dislocation loops remains nearly the same, while dislocation density was reduced almost by one fold. In the areas where dislocation density was found to be the lowest some features, which can most likely be attributed to stacking fault tetrahedral (SFT) were found. Annealing at even higher temperature (550 C.) affected the average size of the dislocation loops, making them almost twice as large as well as resulting in a very broad distribution of dislocation sizes. Density of dislocations is also reduced by one fold in comparison to the as irradiated condition and leads to formation of SFTs, which could be

Final report on cermet high-level waste forms

International Nuclear Information System (INIS)

Kobisk, E.H.; Quinby, T.C.; Aaron, W.S.

1981-08-01

Cermets are being developed as an alternate method for the fixation of defense and commercial high level radioactive waste in a terminal disposal form. Following initial feasibility assessments of this waste form, consisting of ceramic particles dispersed in an iron-nickel base alloy, significantly improved processing methods were developed. The characterization of cermets has continued through property determinations on samples prepared by various methods from a variety of simulated and actual high-level wastes. This report describes the status of development of the cermet waste form as it has evolved since 1977. 6 tables, 18 figures

High level radioactive waste management facility design criteria

International Nuclear Information System (INIS)

Sheikh, N.A.; Salaymeh, S.R.

1993-01-01

This paper discusses the engineering systems for the structural design of the Defense Waste Processing Facility (DWPF) at the Savannah River Site (SRS). At the DWPF, high level radioactive liquids will be mixed with glass particles and heated in a melter. This molten glass will then be poured into stainless steel canisters where it will harden. This process will transform the high level waste into a more stable, manageable substance. This paper discuss the structural design requirements for this unique one of a kind facility. A special emphasis will be concentrated on the design criteria pertaining to earthquake, wind and tornado, and flooding

Tensile properties of neutron irradiated solid HIP 316L(N). ITER Task T214, NET deliverable GB6 ECN-5

International Nuclear Information System (INIS)

Van Osch, E.V.; Tjoa, G.L.; Boskeljon, J.; Van Hoepen, J.

1998-05-01

The tensile properties of neutron irradiated Hot Isostatically Pressed (HIP) joints of type 316L(N) stainless steel (heat PM-130) have been measured. Cylindrical tensile test specimens of 4 mm diameter were irradiated in the High Flux Reactor (HFR) in Petten, The Netherlands, simulating the first wall conditions by a combination of high displacement damage with proportional amounts of helium. The solid HIP specimens were irradiated up to a target dose level of 5 dpa at a temperature of 550K. The damage levels realized range from 3.0 to 4.1 dpa, with helium contents up to 38 appm. Post irradiation testing temperatures ranged from 300 to 700K. The report contains the experimental conditions and summarises the results, which are given in terms of engineering stresses and strains and reduction of area. The main conclusions are that the unirradiated solid-HIP material is very soft, assumingly due to the relatively large grain size. Neutron irradiation induces both hardening and reduction of ductility, similar to the behaviour of 316L(N) plate. No failures related to debonding were observed for the tests of the unirradiated samples, however one of eight tested irradiated specimens fractured in the HIP joint, showing a flat fracture surface and a low reduction of area. 6 refs

Irradiation creep at temperatures of 400 degrees C and below for application to near-term fusion devices

International Nuclear Information System (INIS)

Grossbeck, M.L.; Gibson, L.T.; Mansur, L.K.

1996-01-01

To study irradiation creep at 400 degrees C and below, a series of six austenitic stainless steels and two ferritic alloys was irradiated sequentially in two research reactors where the neutron spectrum was tailored to produce a He production rate typical of a fusion device. Irradiation began in the Oak Ridge Research Reactor; and, after an atomic displacement level of 7.4 dpa, the specimens were moved to the High Flux Isotope Reactor for the remainder of the 19 dpa accumulated. Irradiation temperatures of 60, 200, 330, and 400 degrees C were studied with internally pressurized tubes of type 316 stainless steel, PCA, HT 9, and a series of four laboratory heats of: Fe-13.5Cr-15Ni, Fe-13.5Cr-35Ni, Fe-1 3.5Cr-1 W-0.18Ti, and Fe-16Cr. At 330 degrees C, irradiation creep was shown to be linear in fluence and stress. There was little or no effect of cold-work on creep under these conditions at all temperatures investigated. The HT9 demonstrated a large deviation from linearity at high stress levels, and a minimum in irradiation creep with increasing stress was observed in the Fe-Cr-Ni ternary alloys

Ontology-Based High-Level Context Inference for Human Behavior Identification

Science.gov (United States)

Villalonga, Claudia; Razzaq, Muhammad Asif; Khan, Wajahat Ali; Pomares, Hector; Rojas, Ignacio; Lee, Sungyoung; Banos, Oresti

2016-01-01

Recent years have witnessed a huge progress in the automatic identification of individual primitives of human behavior, such as activities or locations. However, the complex nature of human behavior demands more abstract contextual information for its analysis. This work presents an ontology-based method that combines low-level primitives of behavior, namely activity, locations and emotions, unprecedented to date, to intelligently derive more meaningful high-level context information. The paper contributes with a new open ontology describing both low-level and high-level context information, as well as their relationships. Furthermore, a framework building on the developed ontology and reasoning models is presented and evaluated. The proposed method proves to be robust while identifying high-level contexts even in the event of erroneously-detected low-level contexts. Despite reasonable inference times being obtained for a relevant set of users and instances, additional work is required to scale to long-term scenarios with a large number of users. PMID:27690050

Ontology-Based High-Level Context Inference for Human Behavior Identification

Directory of Open Access Journals (Sweden)

Claudia Villalonga

2016-09-01

Full Text Available Recent years have witnessed a huge progress in the automatic identification of individual primitives of human behavior, such as activities or locations. However, the complex nature of human behavior demands more abstract contextual information for its analysis. This work presents an ontology-based method that combines low-level primitives of behavior, namely activity, locations and emotions, unprecedented to date, to intelligently derive more meaningful high-level context information. The paper contributes with a new open ontology describing both low-level and high-level context information, as well as their relationships. Furthermore, a framework building on the developed ontology and reasoning models is presented and evaluated. The proposed method proves to be robust while identifying high-level contexts even in the event of erroneously-detected low-level contexts. Despite reasonable inference times being obtained for a relevant set of users and instances, additional work is required to scale to long-term scenarios with a large number of users.

Geographical distribution of drinking-water with high iodine level and association between high iodine level in drinking-water and goitre: a Chinese national investigation.

Science.gov (United States)

Shen, Hongmei; Liu, Shoujun; Sun, Dianjun; Zhang, Shubin; Su, Xiaohui; Shen, Yanfeng; Han, Hepeng

2011-07-01

Excessive iodine intake can cause thyroid function disorders as can be caused by iodine deficiency. There are many people residing in areas with high iodine levels in drinking-water in China. The main aim of the present study was to map the geographical distribution of drinking-water with high iodine level in China and to determine the relationship between high iodine level in drinking-water and goitre prevalence. Iodine in drinking-water was measured in 1978 towns of eleven provinces in China, with a total of 28,857 water samples. We randomly selected children of 8-10 years old, examined the presence of goitre and measured their urinary iodine in 299 towns of nine provinces. Of the 1978 towns studied, 488 had iodine levels between 150 and 300 μg/l in drinking-water, and in 246 towns, the iodine level was >300 μg/l. These towns are mainly distributed along the original Yellow River flood areas, the second largest river in China. Of the 56 751 children examined, goitre prevalence was 6.3 % in the areas with drinking-water iodine levels of 150-300 μg/l and 11.0 % in the areas with drinking-water iodine >300 μg/l. Goitre prevalence increased with water and urinary iodine levels. For children with urinary iodine >1500 μg/l, goitre prevalence was 3.69 times higher than that for those with urinary iodine levels of 100-199 μg/l. The present study suggests that drinking-water with high iodine levels is distributed in eleven provinces of China. Goitre becomes more prevalent with the increase in iodine level in drinking-water. Therefore, it becomes important to prevent goitre through stopping the provision of iodised salt and providing normal drinking-water iodine through pipelines in these areas in China.

Microstructure and Nano-Hardness of 10 MeV Cl-Ion Irradiated T91 Steel

International Nuclear Information System (INIS)

Hu Jing; Wang Xianping; Gao Yunxia; Zhuang Zhong; Zhang Tao; Fang Qianfeng; Liu Changsong

2015-01-01

Hardening and elemental segregation of T91 martenstic steel irradiated by 10 MeV Cl ions to doses from 0.06 dpa to 0.83 dpa were investigated with the nanoindentation technique and transmission electron microscopy (TEM). The results demonstrated that the irradiation hardening was closely related with irradiation dose. By increasing the dose, the hardness increased rapidly at first from the initial value of 3.15 GPa before irradiation, and then tended to saturate at a value of 3.58 GPa at the highest dose of 0.83 dpa. Combined with TEM observation, the mechanism of hardening was preliminary attributed to the formation of M(Fe,Cr) 2 3C 6 carbides induced by the high energy Cl-ion irradiation. (paper)

PAIRWISE BLENDING OF HIGH LEVEL WASTE

International Nuclear Information System (INIS)

CERTA, P.J.

2006-01-01

The primary objective of this study is to demonstrate a mission scenario that uses pairwise and incidental blending of high level waste (HLW) to reduce the total mass of HLW glass. Secondary objectives include understanding how recent refinements to the tank waste inventory and solubility assumptions affect the mass of HLW glass and how logistical constraints may affect the efficacy of HLW blending

High-level radioactive wastes. Supplement 1

International Nuclear Information System (INIS)

McLaren, L.H.

1984-09-01

This bibliography contains information on high-level radioactive wastes included in the Department of Energy's Energy Data Base from August 1982 through December 1983. These citations are to research reports, journal articles, books, patents, theses, and conference papers from worldwide sources. Five indexes, each preceded by a brief description, are provided: Corporate Author, Personal Author, Subject, Contract Number, and Report Number. 1452 citations

Synthesis of new molecular probes radiolabelled with fluorine-18 for imaging neuro-inflammation with Positon Emission Tomography

International Nuclear Information System (INIS)

Medran-Navarrete, Vincent

2014-01-01

The work presented in this manuscript aims to describe the synthesis of new ligands of the translocation protein 18 kDa (TSPO), their in vitro evaluation and, for the most promising candidates, their isotopic radiolabelling with the short-lived positron emitter fluorine-18 (t 1/2 : 109.8 minutes). The ultimate goal of this work consists in developing new molecular probes, or bio-markers, for imaging neuro-inflammation in a non-invasive and atraumatic manor using Positron Emission Tomography (PET). Neuro-inflammatory processes have been identified in Alzheimer and Parkinson diseases, MS and various psychiatric pathologies. The radioligand of choice for imaging TSPO is currently [ 18 F]DPA-714, a pyr-azolo[1,5-a]pyrimidine radiolabelled with fluorine-18 which has been recently prepared in our laboratories. However, [ 18 F]DPA-714 undergoes a rapid in vivo loss of the radioactive fluorine by cleavage of the fluoro-alkoxy chain as demonstrated in metabolic studies. Therefore, my PhD project aimed to design and develop new structurally related analogues of DPA-714 where the linkage between the main backbone and the fluorine-18 would be reinforced. To this extent, nineteen compounds were prepared and their affinity towards the TSPO was evaluated. Two promising candidates, coded DPA-C5yne and CfO-DPA-714, were radiolabelled with fluorine-18 with good radiochemical yields (20-30 %) and high specific radioactivities (50-90 GBq/μmol). These radioligands were also evaluated by PET imaging at the preclinical stage and displayed equivalent or slightly improved results when compared to [ 18 F]DPA- 714. (author) [fr

A high Tc superconducting liquid nitrogen level sensor

International Nuclear Information System (INIS)

Jin, J. X.; Liu, H. K.; Dou, S. X.; Grantham, C.; Beer, J.

1996-01-01

Full text: The dramatic resistance change in the superconducting-normal transition temperature range enables a high T c superconductor to be considered for designing a liquid nitrogen level sensor. A (Bi,Pb) 2 Sr 2 Ca 2 Cu 3 O 10+x Ag clad superconducting wire is selected and tested as a continuous liquid nitrogen level sensor to investigate the possibility for this application. The (Bi,Pb) 2 Sr 2 Ca 2 Cu 3 O 10+x Ag clad superconducting wire has approximately 110 K critical temperature, with more flexible and stable properties compared with bulk shape ceramic high T c superconductors. The voltage drops across the sensor are tested with different immersion lengths in liquid nitrogen. The accuracy of the HTS sensor is analysed with its dR/dT in the superconducting-normal transition range. The voltage signal is sensitive to liquid nitrogen level change, and this signal can be optimized by controlling the transport current. The problems of the Ag clad superconductor are that the Ag sheath thermal conductivity is very high, and the sensor normal resistance is low. These are the main disadvantages for using such a wire as a continuous level sensor. However, a satisfactory accuracy can be achieved by control of the transport current. A different configuration of the wire sensor is also designed to avoid this thermal influence

Multi-threaded algorithms for GPGPU in the ATLAS High Level Trigger

CERN Document Server

AUTHOR|(INSPIRE)INSPIRE-00212700; The ATLAS collaboration

2017-01-01

General purpose Graphics Processor Units (GPGPU) are being evaluated for possible future inclusion in an upgraded ATLAS High Level Trigger farm. We have developed a demonstrator including GPGPU implementations of Inner Detector and Muon tracking and Calorimeter clustering within the ATLAS software framework. ATLAS is a general purpose particle physics experiment located on the LHC collider at CERN. The ATLAS Trigger system consists of two levels, with Level-1 implemented in hardware and the High Level Trigger implemented in software running on a farm of commodity CPU. The High Level Trigger reduces the trigger rate from the 100 kHz Level-1 acceptance rate to 1.5 kHz for recording, requiring an average per-event processing time of ∼ 250 ms for this task. The selection in the high level trigger is based on reconstructing tracks in the Inner Detector and Muon Spectrometer and clusters of energy deposited in the Calorimeter. Performing this reconstruction within the available farm resources presents a significa...

Dose dependence of nano-hardness of 6H-SiC crystal under irradiation with inert gas ions

Science.gov (United States)

Yang, Yitao; Zhang, Chonghong; Su, Changhao; Ding, Zhaonan; Song, Yin

2018-05-01

Single crystal 6H-SiC was irradiated by inert gas ions (He, Ne, Kr and Xe ions) to various damage levels at room temperature. Nano-indentation test was performed to investigate the hardness change behavior with damage. The depth profile of nano-hardness for 6H-SiC decreased with increasing depth for both the pristine and irradiated samples, which was known as indentation size effect (ISE). Nix-Gao model was proposed to determine an asymptotic value of nano-hardness by taking account of ISE for both the pristine and irradiated samples. In this study, nano-hardness of the irradiated samples showed a strong dependence on damage level and showed a weak dependence on ions species. From the dependence of hardness on damage, it was found that the change of hardness demonstrated three distinguishable stages with damage: (I) The hardness increased with damage from 0 to 0.2 dpa and achieved a maximum of hardening fraction ∼20% at 0.2 dpa. The increase of hardness in this damage range was contributed to defects produced by ion irradiation, which can be described well by Taylor relation. (II) The hardness reduced rapidly with large decrement in the damage range from 0.2 to 0.5 dpa, which was considered to be from the covalent bond breaking. (III) The hardness reduced with small decrement in the damage range from 0.5 to 2.2 dpa, which was induced by extension of the amorphous layer around damage peak.

Engineering materials for high level radioactive waste repository

International Nuclear Information System (INIS)

Wen Zhijian

2009-01-01

Radioactive wastes can arise from a wide range of human activities and have different physical and chemical forms with various radioactivity. The high level radioactive wastes (HLW)are characterized by nuclides of very high initial radioactivity, large thermal emissivity and the long life-term. The HLW disposal is highly concerned by the scientists and the public in the world. At present, the deep geological disposal is regarded as the most reasonable and effective way to safely dispose high-level radioactive wastes in the world. The conceptual model of HLW geological disposal in China is based on a multi-barrier system that combines an isolating geological environment with an engineering barrier system(EBS). The engineering materials in EBS include the vitrified HLW, canister, overpack, buffer materials and backfill materials. Referring to progress in the world, this paper presents the function, the requirement for material selection and design, and main scientific projects of R and D of engineering materials in HLW repository. (authors)

Cermets for high level waste containment

International Nuclear Information System (INIS)

Aaron, W.S.; Quinby, T.C.; Kobisk, E.H.

1978-01-01

Cermet materials are currently under investigation as an alternate for the primary containment of high level wastes. The cermet in this study is an iron--nickel base metal matrix containing uniformly dispersed, micron-size fission product oxides, aluminosilicates, and titanates. Cermets possess high thermal conductivity, and typical waste loading of 70 wt % with volume reduction factors of 2 to 200 and low processing volatility losses have been realized. Preliminary leach studies indicate a leach resistance comparable to other candidate waste forms; however, more quantitative data are required. Actual waste studies have begun on NFS Acid Thorex, SRP dried sludge and fresh, unneutralized SRP process wastes

The Influence of Decreased Levels of High Density Lipoprotein ...

African Journals Online (AJOL)

Background: Changes in lipoproteins levels in sickle cell disease (SCD) patients are well.known, but the physiological ramifications of the low levels observed have not been entirely resolved. Aim: The aim of this study is to evaluate the impact of decreased levels of high density lipoprotein cholesterol (HDL.c) on ...

Sensitive and selective determination of Cu2+ at D-penicillamine functionalized nano-cellulose modified pencil graphite electrode

Science.gov (United States)

Taheri, M.; Ahour, F.; Keshipour, S.

2018-06-01

A novel electrochemical sensor based on D-penicillamine anchored nano-cellulose (DPA-NC) modified pencil graphite electrode was fabricated and used for highly selective and sensitive determination of copper (II) ions in the picomolar concentration by square wave adsorptive stripping voltammetric (SWV) method. The modified electrode showed better and increased SWV response compared to the bare and NC modified electrodes which may be related to the porous structure of modifier along with formation of complex between Cu2+ ions and nitrogen or oxygen containing groups in DPA-NC. Optimization of various experimental parameters influence the performance of the sensor, were investigated. Under optimized condition, DPA-NC modified electrode was used for the analysis of Cu2+ in the concentration range from 0.2 to 50 pM, and a lower detection limit of 0.048 pM with good stability, repeatability, and selectivity. Finally, the practical applicability of DPA-NC-PGE was confirmed via measuring trace amount of Cu (II) in tap and river water samples.

Treatment of High-Level Waste Arising from Pyrochemical Processes

International Nuclear Information System (INIS)

Lizin, A.A.; Kormilitsyn, M.V.; Osipenko, A.G.; Tomilin, S.V.; Lavrinovich, Yu.G.

2013-01-01

JSC “SSC RIAR” has been performing research and development activities in support of closed fuel cycle of fast reactor since the middle of 1960s. Fuel cycle involves fabrication and reprocessing of spent nuclear fuel (SNF) using pyrochemical methods of reprocessing in molten alkali metal chlorides. At present pyrochemical methods of SNF reprocessing in molten chlorides has reached such a level in their development that makes it possible to compare their competitiveness with classic aqueous methods. Their comparative advantage lies in high safety, compactness, high protectability as to nonproliferation of nuclear materials, and reduction of high level waste volume

Very-high-level neutral-beam control system

International Nuclear Information System (INIS)

Elischer, V.; Jacobson, V.; Theil, E.

1981-10-01

As increasing numbers of neutral beams are added to fusion machines, their operation can consume a significant fraction of a facility's total resources. LBL has developed a very high level control system that allows a neutral beam injector to be treated as a black box with just 2 controls: one to set the beam power and one to set the pulse duration. This 2 knob view allows simple operation and provides a natural base for implementing even higher level controls such as automatic source conditioning

High-level radioactive wastes. Supplement 1

Energy Technology Data Exchange (ETDEWEB)

McLaren, L.H. (ed.)

1984-09-01

This bibliography contains information on high-level radioactive wastes included in the Department of Energy's Energy Data Base from August 1982 through December 1983. These citations are to research reports, journal articles, books, patents, theses, and conference papers from worldwide sources. Five indexes, each preceded by a brief description, are provided: Corporate Author, Personal Author, Subject, Contract Number, and Report Number. 1452 citations.

Decommissioning high-level waste surface facilities

International Nuclear Information System (INIS)

1978-04-01

The protective storage, entombment and dismantlement options of decommissioning a High-Level Waste Surface Facility (HLWSF) was investigated. A reference conceptual design for the facility was developed based on the designs of similar facilities. State-of-the-art decommissioning technologies were identified. Program plans and cost estimates for decommissioning the reference conceptual designs were developed. Good engineering design concepts were on the basis of this work identified

Removal of phosphate using copper-loaded polymeric ligand exchanger prepared by radiation grafting of polypropylene/polyethylene (PP/PE) nonwoven fabric

Science.gov (United States)

Barsbay, Murat; Kavaklı, Pınar Akkaş; Güven, Olgun

2010-03-01

A novel polymeric ligand exchanger (PLE) was prepared for the removal of phosphate ions from water. 2,2'-dipyridylamine (DPA), a bidentate ligand forming compound with high coordination capacity with a variety of metal ions was bound to glycidyl methacrylate (GMA) grafted polypropylene/polyethylene (PP/PE) nonwoven fabric synthesized by radiation-induced grafting technique. DPA attachment on epoxy ring of GMA units was tested in different solvents, i.e. methanol, ethanol, dioxane and dimethylsulfoxide (DMSO). The highest amount of modification was achieved in dioxane. In order to prepare the corresponding PLE for the removal of phosphate, DPA-immobilized fabric was loaded with Cu(II) ions. Phosphate adsorption experiments were performed in batch mode at different pH (5-9) and phosphate concentrations. The fabric was found to be effective for the removal of phosphate ions. At every stage of preparation and use, the nonwoven fabric was characterized by thermal (i.e. DSC and TGA) and spectroscopic (FTIR) methods. Competitive adsorption experiments were also carried out using two solutions with different concentration levels at pH 7 to see the effect of competing ions. Phosphate adsorption was found to be effective and selective from solutions having trace amounts of competitive anions. It is expected that the novel PLE synthesized can be used for the removal of phosphate ions in low concentrations over a large range of pH.

Thermal conductivity degradation of graphites due to neutron irradiation at low temperature

International Nuclear Information System (INIS)

Snead, L.L.; Burchell, T.D.

1995-01-01

Several graphites and carbon/carbon composites (C/C's) have been irradiated with fission neutrons near 150 C and at fluences up to a displacement level of 0.24 dpa. The unirradiated room temperature thermal conductivity of these materials varied from 114 W/m K for H-451 isotropic graphite, to 670 W/m K for a unidirectional FMI-1D C/C composite. At the irradiation temperature a saturation reduction in thermal conductivity was seen to occur at displacement levels of approximately 0.1 dpa. All materials were seen to degrade to approximately 10 to 14% of their original thermal conductivity after irradiation. The significant recovery of thermal conductivity due to post-irradiation isochronal anneals is also presented. (orig.)

Omega-3 fatty acids status in human subjects estimated using a food frequency questionnaire and plasma phospholipids levels

Directory of Open Access Journals (Sweden)

Garneau Véronique

2012-07-01

Full Text Available Abstract Background Intakes of omega-3 (n-3 fatty acids (FA are associated with several health benefits. The aim of this study was to verify whether intakes of n-3 FA estimated from a food frequency questionnaire (FFQ correlate with n-3 FA levels measured in plasma phospholipids (PL. Methods The study sample consisted of 200 French-Canadians men and women aged between 18 to 55 years. Dietary data were collected using a validated FFQ. Fasting blood samples were collected and the plasma PL FA profile was measured by gas chromatography. Results Low intakes of n-3 long-chain FA together with low percentages of n-3 long-chain FA in plasma PL were found in French-Canadian population. Daily intakes of eicosapentaenoic acid (EPA, docosapentaenoic acid (DPA and docosahexaenoic acid (DHA were similar between men and women. Yet, alpha-linolenic acid (ALA and total n-3 FA intakes were significantly higher in men compared to women (ALA: 2.28 g and 1.69 g, p n-3 FA: 2.57 g and 1.99 g, p n-3 FA (men: r = 0.47, p  Conclusion Estimated n-3 long-chain FA intake among this young and well-educated French-Canadian population is lower than the recommendations. Further, FFQ data is comparable to plasma PL results to estimate DHA and total n-3 FA status in healthy individuals as well as to evaluate the EPA and DPA status in women. Overall, this FFQ could be used as a simple, low-cost tool in future studies to rank n-3 FA status of individuals.

Low Power Design with High-Level Power Estimation and Power-Aware Synthesis

CERN Document Server

Ahuja, Sumit; Shukla, Sandeep Kumar

2012-01-01

Low-power ASIC/FPGA based designs are important due to the need for extended battery life, reduced form factor, and lower packaging and cooling costs for electronic devices. These products require fast turnaround time because of the increasing demand for handheld electronic devices such as cell-phones, PDAs and high performance machines for data centers. To achieve short time to market, design flows must facilitate a much shortened time-to-product requirement. High-level modeling, architectural exploration and direct synthesis of design from high level description enable this design process. This book presents novel research techniques, algorithms,methodologies and experimental results for high level power estimation and power aware high-level synthesis. Readers will learn to apply such techniques to enable design flows resulting in shorter time to market and successful low power ASIC/FPGA design. Integrates power estimation and reduction for high level synthesis, with low-power, high-level design; Shows spec...

Interaction between High-Level and Low-Level Image Analysis for Semantic Video Object Extraction

Directory of Open Access Journals (Sweden)

Andrea Cavallaro

2004-06-01

Full Text Available The task of extracting a semantic video object is split into two subproblems, namely, object segmentation and region segmentation. Object segmentation relies on a priori assumptions, whereas region segmentation is data-driven and can be solved in an automatic manner. These two subproblems are not mutually independent, and they can benefit from interactions with each other. In this paper, a framework for such interaction is formulated. This representation scheme based on region segmentation and semantic segmentation is compatible with the view that image analysis and scene understanding problems can be decomposed into low-level and high-level tasks. Low-level tasks pertain to region-oriented processing, whereas the high-level tasks are closely related to object-level processing. This approach emulates the human visual system: what one “sees” in a scene depends on the scene itself (region segmentation as well as on the cognitive task (semantic segmentation at hand. The higher-level segmentation results in a partition corresponding to semantic video objects. Semantic video objects do not usually have invariant physical properties and the definition depends on the application. Hence, the definition incorporates complex domain-specific knowledge and is not easy to generalize. For the specific implementation used in this paper, motion is used as a clue to semantic information. In this framework, an automatic algorithm is presented for computing the semantic partition based on color change detection. The change detection strategy is designed to be immune to the sensor noise and local illumination variations. The lower-level segmentation identifies the partition corresponding to perceptually uniform regions. These regions are derived by clustering in an N-dimensional feature space, composed of static as well as dynamic image attributes. We propose an interaction mechanism between the semantic and the region partitions which allows to

Coastal barrier stratigraphy for Holocene high-resolution sea-level reconstruction.

Science.gov (United States)

Costas, Susana; Ferreira, Óscar; Plomaritis, Theocharis A; Leorri, Eduardo

2016-12-08

The uncertainties surrounding present and future sea-level rise have revived the debate around sea-level changes through the deglaciation and mid- to late Holocene, from which arises a need for high-quality reconstructions of regional sea level. Here, we explore the stratigraphy of a sandy barrier to identify the best sea-level indicators and provide a new sea-level reconstruction for the central Portuguese coast over the past 6.5 ka. The selected indicators represent morphological features extracted from coastal barrier stratigraphy, beach berm and dune-beach contact. These features were mapped from high-resolution ground penetrating radar images of the subsurface and transformed into sea-level indicators through comparison with modern analogs and a chronology based on optically stimulated luminescence ages. Our reconstructions document a continuous but slow sea-level rise after 6.5 ka with an accumulated change in elevation of about 2 m. In the context of SW Europe, our results show good agreement with previous studies, including the Tagus isostatic model, with minor discrepancies that demand further improvement of regional models. This work reinforces the potential of barrier indicators to accurately reconstruct high-resolution mid- to late Holocene sea-level changes through simple approaches.

Effect of neutron radiation on the dielectric, mechanical and thermal properties of ceramics for RF transmission windows

International Nuclear Information System (INIS)

Hazelton, C.; Rice, J.; Snead, L.L.; Zinkle, S.J.

1998-01-01

The behavior of electrically insulating ceramics was investigated before and after exposure to neutron radiation. Mechanical, thermal and dielectric specimens were studied after exposure to a fast neutron dose of 0.1 displacements per atom (dpa) at Oak Ridge National Laboratory (ORNL). Four materials were compared to alumina: polycrystalline spinel, aluminum nitride, sialon and silicon nitride. Mechanical bend tests were performed before and after irradiation. Thermal diffusivity was measured using a room temperature laser flash technique. Dielectric loss factor was measured at 105 MHz with a special high resolution resonance cavity. The materials exhibited a significant degradation of thermal diffusivity and an increase in dielectric loss tangent. The flexural strength and physical dimensions were not significantly affected by the 0.1 dpa level of neutron radiation. The aluminum nitride and S silicon nitride showed superior RF window performance over the sialon and the alumina. The results are compared to radiation studies on similar materials

Fluorescent detection of dipicolinic acid as a biomarker of bacterial spores using lanthanide-chelated gold nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Donmez, Mert [Department of Chemistry, Faculty of Art and Sciences, Duzce University, Duzce 81620 (Turkey); Yilmaz, M. Deniz, E-mail: deniz.yilmaz@gidatarim.edu.tr [Department of Bioengineering, Faculty of Engineering and Architecture, Konya Food and Agriculture University, Konya 42080 (Turkey); Kilbas, Benan, E-mail: benankilbas@duzce.edu.tr [Department of Chemistry, Faculty of Art and Sciences, Duzce University, Duzce 81620 (Turkey)

2017-02-15

Highlights: • The nanosensors based on gold nanoparticles functionalized with lanthanide complexes were synthesized. • The nanosensors selectively and sensitively detected DPA, a biomarker of bacterial spores. • Ratiometric sensing of DPA by a ternary complex was achieved by ligand displacement strategy. - Abstract: Gold nanoparticles (GNPs) functionalized with ethylenediamine-lanthanide complexes (Eu-GNPs and Tb-GNPs) were used for the selective fluorescent detection of dipicolinic acid (DPA), a unique biomarker of bacterial spores, in water. Particles were characterized by transmission electron microscopy and zeta potential measurements. The coordination of DPA to the lanthanides resulted in the enhancement of the fluorescence. A selective response to DPA was observed over the nonselective binding of aromatic ligands. The ligand displacement strategy were also employed for the ratiometric fluorescent detection of DPA. 4,4,4-trifluoro-1-(2-naphthyl)-1,3-butanedion (TFNB) was chosen as an antenna to synthesize ternary complexes. The addition of DPA on EuGNP:TFNB ternary complex quenched the initial emission of the complex at 615 nm and increased the TFNB emission at 450 nm when excited at 350 nm. The results demonstrated that the ratiometric fluorescent detection of DPA was achieved by ligand displacement strategy.

Influence of irradiation spectrum and implanted ions on the amorphization of ceramics

International Nuclear Information System (INIS)

Zinkle, S.J.; Snead, L.L.

1995-01-01

Polycrystalline Al2O3, magnesium aluminate spinel (MgAl2O4), MgO, Si3N4, and SiC were irradiated with various ions at 200-450 K, and microstructures were examined following irradiation using cross-section TEM. Amorphization was not observed in any of the irradiated oxide ceramics, despsite damage energy densities up to ∼7 keV/atom (70 displacements per atom). On the other hand, SiC readily amorphized after damage levels of ∼0.4 dpa at room temperature (RT). Si3N4 exhibited intermediate behavior; irradiation with Fe 2+ ions at RT produced amorphization in the implanted ion region after damage levels of ∼1 dpa. However, irradiated regions outside the implanted ion region did not amorphize even after damage levels > 5 dpa. The amorphous layer in the Fe-implanted region of Si3N4 did not appear if the specimen was simultaneoulsy irradiated with 1-MeV He + ions at RT. By comparison with published results, it is concluded that the implantation of certain chemical species has a pronounced effect on the amorphization threshold dose of all five materials. Intense ionizing radiation inhibits amorphization in Si3N4, but does not appear to significantly influence the amorphization of SiC

Performance of the CMS High Level Trigger

CERN Document Server

Perrotta, Andrea

2015-01-01

The CMS experiment has been designed with a 2-level trigger system. The first level is implemented using custom-designed electronics. The second level is the so-called High Level Trigger (HLT), a streamlined version of the CMS offline reconstruction software running on a computer farm. For Run II of the Large Hadron Collider, the increases in center-of-mass energy and luminosity will raise the event rate to a level challenging for the HLT algorithms. The increase in the number of interactions per bunch crossing, on average 25 in 2012, and expected to be around 40 in Run II, will be an additional complication. We present here the expected performance of the main triggers that will be used during the 2015 data taking campaign, paying particular attention to the new approaches that have been developed to cope with the challenges of the new run. This includes improvements in HLT electron and photon reconstruction as well as better performing muon triggers. We will also present the performance of the improved trac...

Effects of neutron irradiation of Ti{sub 3}SiC{sub 2} and Ti{sub 3}AlC{sub 2} in the 121–1085 °C temperature range

Energy Technology Data Exchange (ETDEWEB)

Tallman, Darin J. [Department of Materials Science and Engineering, Drexel University, Philadelphia, PA 19104 (United States); He, Lingfeng; Gan, Jian [Idaho National Laboratory, Idaho Falls, ID 83415 (United States); Caspi, El' ad N. [Department of Materials Science and Engineering, Drexel University, Philadelphia, PA 19104 (United States); Physics Department, Nuclear Research Centre – Negev, 84190 Israel (Israel); Hoffman, Elizabeth N. [Savannah River National Laboratory, Savannah River Site, Aiken, SC 29808 (United States); Barsoum, Michel W., E-mail: barsoumw@drexel.edu [Department of Materials Science and Engineering, Drexel University, Philadelphia, PA 19104 (United States)

2017-02-15

Herein we report on the formation of defects in response to neutron irradiation of polycrystalline Ti{sub 3}SiC{sub 2} and Ti{sub 3}AlC{sub 2} samples exposed to total fluences of ≈6 × 10{sup 20} n/m{sup 2}, 5 × 10{sup 21} n/m{sup 2} and 1.7 × 10{sup 22} n/m{sup 2} at irradiation temperatures of 121(12), 735(6) and 1085(68)°C. These fluences correspond to 0.14, 1.6 and 3.4 dpa, respectively. After irradiation to 0.14 dpa at 121 °C and 735 °C, black spots are observed via transmission electron microscopy in both Ti{sub 3}SiC{sub 2} and Ti{sub 3}AlC{sub 2}. After irradiation to 1.6 and 3.4 dpa at 735 °C, basal dislocation loops, with a Burgers vector of b = ½ [0001] are observed in Ti{sub 3}SiC{sub 2}, with loop diameters of 21(6) and 30(8) nm after 1.6 dpa and 3.4 dpa, respectively. In Ti{sub 3}AlC{sub 2}, larger dislocation loops, 75(34) nm in diameter are observed after 3.4 dpa at 735 °C, in addition to stacking faults. Impurity particles of TiC, as well as stacking fault TiC platelets in the MAX phases, are seen to form extensive dislocation loops under all conditions. Cavities were observed at grain boundaries and within stacking faults after 3.4 dpa irradiation, with extensive cavity formation in the TiC regions at 1085 °C. Remarkably, denuded zones on the order of 1 μm are observed in Ti{sub 3}SiC{sub 2} after irradiation to 3.4 dpa at 735 °C. Small grains, 3–5 μm in diameter, are damage free after irradiation at 1085 °C at this dose. The results shown herein confirm once again that the presence of the A-layers in the MAX phases considerably enhance their irradiation tolerance. Based on these results, and up to 3.4 dpa, Ti{sub 3}SiC{sub 2} remains a promising candidate for high temperature nuclear applications as long as the temperature remains >700 °C.

Determination of total cyanide in Hanford Site high-level wastes

Energy Technology Data Exchange (ETDEWEB)

Winters, W.I. [Westinghouse Hanford Co., Richland, WA (United States); Pool, K.H. [Pacific Northwest Lab., Richland, WA (United States)

1994-05-01

Nickel ferrocyanide compounds (Na{sub 2-x}Cs{sub x}NiFe (CN){sub 6}) were produced in a scavenging process to remove {sup 137}Cs from Hanford Site single-shell tank waste supernates. Methods for determining total cyanide in Hanford Site high-level wastes are needed for the evaluation of potential exothermic reactions between cyanide and oxidizers such as nitrate and for safe storage, processing, and management of the wastes in compliance with regulatory requirements. Hanford Site laboratory experience in determining cyanide in high-level wastes is summarized. Modifications were made to standard cyanide methods to permit improved handling of high-level waste samples and to eliminate interferences found in Hanford Site waste matrices. Interferences and associated procedure modifications caused by high nitrates/nitrite concentrations, insoluble nickel ferrocyanides, and organic complexants are described.

Determination of total cyanide in Hanford Site high-level wastes

International Nuclear Information System (INIS)

Winters, W.I.; Pool, K.H.

1994-05-01

Nickel ferrocyanide compounds (Na 2-x Cs x NiFe (CN) 6 ) were produced in a scavenging process to remove 137 Cs from Hanford Site single-shell tank waste supernates. Methods for determining total cyanide in Hanford Site high-level wastes are needed for the evaluation of potential exothermic reactions between cyanide and oxidizers such as nitrate and for safe storage, processing, and management of the wastes in compliance with regulatory requirements. Hanford Site laboratory experience in determining cyanide in high-level wastes is summarized. Modifications were made to standard cyanide methods to permit improved handling of high-level waste samples and to eliminate interferences found in Hanford Site waste matrices. Interferences and associated procedure modifications caused by high nitrates/nitrite concentrations, insoluble nickel ferrocyanides, and organic complexants are described

Imaging anatomy of dorsal pancreatic artery in patients with diabetes: a comparative study between CTA and DSA

International Nuclear Information System (INIS)

Lin Yuning; Li Hui; Yang Xizhang; Chen Ziqian; Tan Jianming; Zhong Qun; Yang Li; Wu Zhixian; Li Huimin; Huang Yisheng

2011-01-01

Objective: To investigate the clinical value of 64-section CT angiography (CTA) in detecting the origin of dorsal pancreatic artery (DPA). Methods: Ninety-seven consecutive patients with diabetes received transcatheter infusion of autologous bone marrow-derived stem cell transplantation into DPA. Abdominal CTA was performed in 42 patients before angiography. Celiac trunk, splenic, common hepatic and superior mesenteric arteries were reconstructed in order to locate the origin and traveling course of DPA. A routine angiography of both celiac and superior mesenteric arteries was performed for the demonstration of DPA. Further angiography of splenic and gastroduodenal arteries was carried out if necessary. Taking DSA images as the reference standard, the sensitivity, specificity and accuracy of CTA for DPA detection were calculated. Results: DPA was the main supply artery of pancreas in 85.7% patients (36/42). CTA demonstrated the origin of DPA in 35 cases, although one of which was confirmed to be misjudged (false positive). In seven cases CTA could not demonstrate DPA, and DSA proved that 2 of them was misjudged (false negative). The sensitivity,specificity and accuracy of CTA for DPA detection were 94.4%, 83.3% and 92.9%, respectively. Conclusion: 64-section CTA can accurately detect the origin of main supply artery of pancreas, which is of great value in guiding the interventional procedure for pancreatic diseases. (authors)

Type GQS-1 high pressure steam manifold water level monitoring system

International Nuclear Information System (INIS)

Li Nianzu; Li Beicheng; Jia Shengming

1993-10-01

The GQS-1 high pressure steam manifold water level monitoring system is an advanced nuclear gauge that is suitable for on-line detecting and monitor in high pressure steam manifold water level. The physical variable of water level is transformed into electrical pulses by the nuclear sensor. A computer is equipped for data acquisition, analysis and processing and the results are displayed on a 14 inch color monitor. In addition, a 4 ∼ 20 mA output current is used for the recording and regulation of water level. The main application of this gauge is for on-line measurement of high pressure steam manifold water level in fossil-fired power plant and other industries

High-level trigger system for the LHC ALICE experiment

CERN Document Server

Bramm, R; Lien, J A; Lindenstruth, V; Loizides, C; Röhrich, D; Skaali, B; Steinbeck, T M; Stock, Reinhard; Ullaland, K; Vestbø, A S; Wiebalck, A

2003-01-01

The central detectors of the ALICE experiment at LHC will produce a data size of up to 75 MB/event at an event rate less than approximately equals 200 Hz resulting in a data rate of similar to 15 GB/s. Online processing of the data is necessary in order to select interesting (sub)events ("High Level Trigger"), or to compress data efficiently by modeling techniques. Processing this data requires a massive parallel computing system (High Level Trigger System). The system will consist of a farm of clustered SMP-nodes based on off- the-shelf PCs connected with a high bandwidth low latency network.

The effect of low temperature neutron irradiation and annealing on the thermal conductivity of advanced carbon-based materials

International Nuclear Information System (INIS)

Barabash, V.; Mazul, I.; Latypov, R.; Pokrovsky, A.; Wu, C.H.

2002-01-01

Several carbon-based materials (carbon fibre composites NB 31, NS 31 and UAM-92, doped graphite RGTi-91), were irradiated at about 90 deg. C in the damage dose range 0.0021-0.13 dpa. Significant reduction of the thermal conductivity of all materials was observed (e.g. at damage dose of ∼0.13 dpa the thermal conductivity degraded up to level of ∼2-3% of the initial values). However, saturation of this effect was observed starting at a dose of ∼0.06 dpa. The effect of annealing at 250 and 350 deg. C on the recovery of thermal conductivity of NB 31 and NS 31 was studied and it was shown this annealing can significantly improve thermal conductivity (∼2.5-3 times). The data on the degradation of the thermal conductivity after additional irradiation after annealing is also reported

Hip Arthroscopy in High-Level Baseball Players.

Science.gov (United States)

Byrd, J W Thomas; Jones, Kay S

2015-08-01

To report the results of hip arthroscopy among high-level baseball players as recorded by outcome scores and return to baseball. All patients undergoing hip arthroscopy were prospectively assessed with the modified Harris Hip Score. On review of all procedures performed over a 12-year period, 44 hips were identified among 41 intercollegiate or professional baseball players who had achieved 2-year follow-up. Among the 41 players, follow-up averaged 45 months (range, 24 to 120 months), with a mean age of 23 years (range, 18 to 34 years). There were 23 collegiate (1 bilateral) and 18 professional (2 bilateral) baseball players, including 10 Major League Baseball players. Of the 8 Major League Baseball pitchers, 6 (75%) also underwent ulnar collateral ligament elbow surgery. Improvement in the modified Harris Hip Score averaged 13 points (from 81 points preoperatively to 94 points postoperatively); a paired-samples t test determined that this mean improvement of 13 points was statistically significant (P arthroscopy. This study supports the idea that arthroscopic treatment for a variety of hip pathologies in high-level baseball players provides a successful return to sport and improvement in functional outcome scores. Level IV, therapeutic case series. Copyright © 2015 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

Space augmentation of military high-level waste disposal

International Nuclear Information System (INIS)

English, T.; Lees, L.; Divita, E.

1979-01-01

Space disposal of selected components of military high-level waste (HLW) is considered. This disposal option offers the promise of eliminating the long-lived radionuclides in military HLW from the earth. A space mission which meets the dual requirements of long-term orbital stability and a maximum of one space shuttle launch per week over a period of 20-40 years, is a heliocentric orbit about halfway between the orbits of earth and Venus. Space disposal of high-level radioactive waste is characterized by long-term predicability and short-term uncertainties which must be reduced to acceptably low levels. For example, failure of either the Orbit Transfer Vehicle after leaving low earth orbit, or the storable propellant stage failure at perihelion would leave the nuclear waste package in an unplanned and potentially unstable orbit. Since potential earth reencounter and subsequent burn-up in the earth's atmosphere is unacceptable, a deep space rendezvous, docking, and retrieval capability must be developed

Development of high-level waste solidification technology 1

Energy Technology Data Exchange (ETDEWEB)

Kim, Joon Hyung; Kim, Hwan Young; Kim, In Tae [and others

1999-02-01

Spent nuclear fuel contains useful nuclides as valuable resource materials for energy, heat and catalyst. High-level wastes (HLW) are expected to be generated from the R and D activities and reuse processes. It is necessary to develop vitrification or advanced solidification technologies for the safe long-term management of high level wastes. As a first step to establish HLW vitrification technology, characterization of HLWs that would arise at KAERI site, glass melting experiments with a lab-scale high frequency induction melter, and fabrication and property evaluation of base-glass made of used HEPA filter media and additives were performed. Basic study on the fabrication and characterization of candidate ceramic waste form (Synroc) was also carried out. These HLW solidification technologies would be directly useful for carrying out the R and Ds on the nuclear fuel cycle and waste management. (author). 70 refs., 29 tabs., 35 figs.

Synthesis and characterization of dipicolinate sensitized LaF3:Tb3+ nanoparticles and their interaction with bovine serum albumin

International Nuclear Information System (INIS)

Jing, Kui; Guo, Xingjia; Diao, Xin; Wu, Qiong; Jiang, Yuchun; Sun, Ye; Pan, Xintong; Zhou, Nannan; Zhu, Yanjun

2015-01-01

Dipicolinate sensitized LaF 3 :Tb 3+ luminescent nanoparticles (DPA-NPs) have been successfully synthesized and characterized for their morphology, structural and optical properties. It was found that the prepared DPA-NPs were spherical with an average diameter of 10 nm and their surfaces were capped by citric acid radicals and DPA. And then the interaction between DPA-NPs and bovine serum albumin (BSA) was investigated by fluorescence quenching, UV–visible absorption, circular dichroism (CD) and Fourier transform infrared (FT-IR) spectroscopy under the simulative physiological conditions. The results showed that DPA-NPs had a strong ability to quench the intrinsic fluorescence of BSA by forming 1:1 ground-state complexes with a binding constant of about 10 4 L mol −1 . Moreover, the values of the calculated thermodynamic parameters suggested that hydrophobic forces and hydrogen bonds played major roles in stabilizing the complex. The displacement experiments indicated that the binding of DPA-NPs primarily occurred in sub-domain II A (site I) of BSA. The binding distance r was calculated to be 1.9 nm based on the theory of Förster's non-radiation energy transfer. Finally, the analysis of synchronous fluorescence, FT-IR, CD, and three-dimensional fluorescence spectra revealed that the microenvironment of amino acid residues and the conformation of BSA were changed after the addition of DPA-NPs. - Highlights: • Dipicolinate sensitized LaF 3 :Tb 3+ luminescent nanoparticles (DPA-NPs) were synthesized by the hydrothermal method. • DPA-NPs have a strong ability to quench the intrinsic fluorescence of BSA by forming a 1:1 ground state complex. • Hydrophobic force and hydrogen bond played major roles in the binding of DPA-NPs to BSA. • The microenvironment of amino acid residues and the conformation of BSA were changed upon addition of DPA-NPs

The CMS High Level Trigger System

CERN Document Server

Afaq, A; Bauer, G; Biery, K; Boyer, V; Branson, J; Brett, A; Cano, E; Carboni, A; Cheung, H; Ciganek, M; Cittolin, S; Dagenhart, W; Erhan, S; Gigi, D; Glege, F; Gómez-Reino, Robert; Gulmini, M; Gutiérrez-Mlot, E; Gutleber, J; Jacobs, C; Kim, J C; Klute, M; Kowalkowski, J; Lipeles, E; Lopez-Perez, Juan Antonio; Maron, G; Meijers, F; Meschi, E; Moser, R; Murray, S; Oh, A; Orsini, L; Paus, C; Petrucci, A; Pieri, M; Pollet, L; Rácz, A; Sakulin, H; Sani, M; Schieferdecker, P; Schwick, C; Sexton-Kennedy, E; Sumorok, K; Suzuki, I; Tsirigkas, D; Varela, J

2007-01-01

The CMS Data Acquisition (DAQ) System relies on a purely software driven High Level Trigger (HLT) to reduce the full Level-1 accept rate of 100 kHz to approximately 100 Hz for archiving and later offline analysis. The HLT operates on the full information of events assembled by an event builder collecting detector data from the CMS front-end systems. The HLT software consists of a sequence of reconstruction and filtering modules executed on a farm of O(1000) CPUs built from commodity hardware. This paper presents the architecture of the CMS HLT, which integrates the CMS reconstruction framework in the online environment. The mechanisms to configure, control, and monitor the Filter Farm and the procedures to validate the filtering code within the DAQ environment are described.

Processing vessel for high level radioactive wastes

International Nuclear Information System (INIS)

Maekawa, Hiromichi

1998-01-01

Upon transferring an overpack having canisters containing high level radioactive wastes sealed therein and burying it into an underground processing hole, an outer shell vessel comprising a steel plate to be fit and contained in the processing hole is formed. A bury-back layer made of dug earth and sand which had been discharged upon forming the processing hole is formed on the inner circumferential wall of the outer shell vessel. A buffer layer having a predetermined thickness is formed on the inner side of the bury-back layer, and the overpack is contained in the hollow portion surrounded by the layer. The opened upper portion of the hollow portion is covered with the buffer layer and the bury-back layer. Since the processing vessel having a shielding performance previously formed on the ground, the state of packing can be observed. In addition, since an operator can directly operates upon transportation and burying of the high level radioactive wastes, remote control is no more necessary. (T.M.)

Results and Prospects of Development of Works on Structural Core Materials for Russian Fast Reactors

International Nuclear Information System (INIS)

Nikitina, A.A.; Ageev, V.S.; Leontyeva-Smirnova, M.V.; Mitrofanova, N.M.; Tselishchev, A.V.

2015-01-01

The strategy of development of atomic energy in Russia in the first half of XXI century contemplates construction and putting in operation of fast reactors of new generation with different types of coolant: sodium (BN-800, BN-1200, MBIR), lead (BREST-OD-300) and lead-bismuth eutectic (SVBR-100). For assurance of the working capacity of reactors that are under construction and achievement of economically reasonable burn-up of nuclear fuel the structural core materials with necessary level of radiation resistance, heat resistance, corrosion resistance to products of fuel fission, corrosion resistance in coolant and in water must be developed and justified. For sodium cooled reactors the key challenge is creation of radiation resistant and heat resistant cladding materials, which must ensure the achievement of damage doses at least 140 dpa. The solution of this problem is provided by phased use as cladding materials of austenitic steels ChS68 and EK164 (maximum damage doses ~ 92 and ~110-115 dpa, respectively), precipitation-hardening heat resistant ferritic-martensitic steels EK181 and ChS139 (maximum damage dose ~140 dpa) and oxide dispersion strengthened (ODS) steels (maximum damage dose more than 140 dpa). For development of core materials for reactors with lead and lead-bismuth eutectic coolants the most serious challenge is corrosion resistance of materials in coolant. Therefore at present time a very wide range of works on study of corrosion resistance of candidate materials is carrying out. As the basic material for the cladding tubes is considered a ferritic-martensitic steel EP823 with high silicon content. In this report the main results of works on justification of the working capacity of materials of different classes in respect to use it in cores of operating and prospective fast reactors with different types of coolant and prospects of further development of works are presented. (author)

Solidification of Savannah River Plant high level waste

International Nuclear Information System (INIS)

Maher, R.; Shafranek, L.F.; Kelley, J.A.; Zeyfang, R.W.

1981-11-01

Authorization for construction of the Defense Waste Processing Facility (DWPF) is expected in FY 83. The optimum time for stage 2 authorization is about three years later. Detailed design and construction will require approximately five years for stage 1, with stage 2 construction completed about two to three years later. Production of canisters of waste glass would begin in 1988, and the existing backlog of high level waste sludge stored at SRP would be worked off by about the year 2000. Stage 2 operation could begin in 1990. The technology and engineering are ready for construction and eventual operation of the DWPF for immobilizing high level radioactive waste at Savannah River Plant (SRP). Proceeding with this project will provide the public, and the leadership of this country, with a crucial demonstration that a major quantity of existing high level nuclear wastes can be safely and permanently immobilized. Early demonstration will both expedite and facilitate rational decision making on this aspect of the nuclear program. Delay in providing these facilities will result in significant DOE expenditures at SRP for new tanks just for continued temporary storage of wastes, and would probably result in dissipation of the intellectual and planning momentum that has built up in developing the project

Development of a test system for high level liquid waste partitioning

Directory of Open Access Journals (Sweden)

Duan Wu H.

2015-01-01

Full Text Available The partitioning and transmutation strategy has increasingly attracted interest for the safe treatment and disposal of high level liquid waste, in which the partitioning of high level liquid waste is one of the critical technical issues. An improved total partitioning process, including a tri-alkylphosphine oxide process for the removal of actinides, a crown ether strontium extraction process for the removal of strontium, and a calixcrown ether cesium extraction process for the removal of cesium, has been developed to treat Chinese high level liquid waste. A test system containing 72-stage 10-mm-diam annular centrifugal contactors, a remote sampling system, a rotor speed acquisition-monitoring system, a feeding system, and a video camera-surveillance system was successfully developed to carry out the hot test for verifying the improved total partitioning process. The test system has been successfully used in a 160 hour hot test using genuine high level liquid waste. During the hot test, the test system was stable, which demonstrated it was reliable for the hot test of the high level liquid waste partitioning.

Biosynthesis of dipicolinic acid in Clostridium roseum

International Nuclear Information System (INIS)

Prakasan, K.; Sharma, D.

1981-01-01

Dipicolinic acid (DPA) synthesis was studied in Clostridium roseum by permitting the organism to complete vegetative growth in trypticase medium and trasfering the cells to a non-growth-promoting-medium, supplemented with the appropriate 14 C-labelled precursors to complete sporulation and assaying the incorporation of label into DPA. Glu, asp, ala, ser and acetate were found to be efficient precursors of DPA and each one influenced the incorporation of other into DPA. The data suggest that a C 5 precursor is being trasformed into a C 4 intermediate, and a C 2 precursor into a C 4 intermediate, before their entry into DPA carbon structure. A C 4 plus C 3 condensation is favoured over C 5 plus C 2 or other condensation in the DPA biosynthesis. (Author) [pt

Methods of Disposing Of High-Level Radioactive Waste: A Review

International Nuclear Information System (INIS)

Abumurade, K.

2002-01-01

High level nuclear waste from both commercial reactors and defense industry presents a difficult problem to the scientific community as well as the public. The solutions to this problem is still debatable both technically and ethically. There are few methods proposed for disposing of high level waste. Each method has its own advantages and disadvantages. However, the very deep underground geologic repository is the best choice for disposing of high-level radioactive wastes. The cost benefit equation of nuclear power production and its waste is discussed. However, the public should be educated about this matter to minimize the gap between them and the nuclear power community including scientists industry, and governments. (Author) 15 refs., 4 tabs., 1 fig

Extract of mangosteen increases high density lipoprotein levels in rats fed high lipid

Directory of Open Access Journals (Sweden)

Dwi Laksono Adiputro

2013-04-01

Full Text Available Background In cardiovascular medicine, Garcinia mangostana has been used as an antioxidant to inhibit oxidation of low density lipoproteins and as an antiobesity agent. The effect of Garcinia mangostana on hyperlipidemia is unknown. The aim of this study was to evaluate the effect of an ethanolic extract of Garcinia mangostana pericarp on lipid profile in rats fed a high lipid diet. Methods A total of 40 rats were divided into five groups control, high lipid diet, and high lipid diet + ethanolic extract of Garcinia mangostana pericarp at dosages of 200, 400, and 800 mg/kg body weight. The control group received a standard diet for 60 days. The high lipid diet group received standard diet plus egg yolk, goat fat, cholic acid, and pig fat for 60 days with or without ethanolic extract of Garcinia mangostana pericarp by the oral route. After 60 days, rats were anesthesized with ether for collection of blood by cardiac puncture. Analysis of blood lipid profile comprised colorimetric determination of cholesterol, triglyceride, low density lipoprotein (LDL, and high density lipoprotein (HDL. Results From the results of one-way ANOVA it was concluded that there were significant between-group differences in cholesterol, trygliceride, LDL, and HDL levels (p=0.000. Ethanolic extract of Garcinia mangostana pericarp significantly decreased cholesterol, trygliceride, and LDL levels, starting at 400 mg/kg body weight (p=0.000. Ethanolic extract of Garcinia mangostana pericarp significantly increased HDL level starting at 200 mg/kg body weight (p=0.000. Conclusion Ethanolic extract of Garcinia mangostana pericarp has a beneficial effect on lipid profile in rats on a high lipid diet.

Extract of mangosteen increases high density lipoprotein levels in rats fed high lipid

Directory of Open Access Journals (Sweden)

Dwi Laksono Adiputro

2015-12-01

Full Text Available BACKGROUND In cardiovascular medicine, Garcinia mangostana has been used as an antioxidant to inhibit oxidation of low density lipoproteins and as an antiobesity agent. The effect of Garcinia mangostana on hyperlipidemia is unknown. The aim of this study was to evaluate the effect of an ethanolic extract of Garcinia mangostana pericarp on lipid profile in rats fed a high lipid diet. METHODS A total of 40 rats were divided into five groups control, high lipid diet, and high lipid diet + ethanolic extract of Garcinia mangostana pericarp at dosages of 200, 400, and 800 mg/kg body weight. The control group received a standard diet for 60 days. The high lipid diet group received standard diet plus egg yolk, goat fat, cholic acid, and pig fat for 60 days with or without ethanolic extract of Garcinia mangostana pericarp by the oral route. After 60 days, rats were anesthesized with ether for collection of blood by cardiac puncture. Analysis of blood lipid profile comprised colorimetric determination of cholesterol, triglyceride, low density lipoprotein (LDL, and high density lipoprotein (HDL. RESULTS From the results of one-way ANOVA it was concluded that there were significant between-group differences in cholesterol, trygliceride, LDL, and HDL levels (p=0.000. Ethanolic extract of Garcinia mangostana pericarp significantly decreased cholesterol, trygliceride, and LDL levels, starting at 400 mg/kg body weight (p=0.000. Ethanolic extract of Garcinia mangostana pericarp significantly increased HDL level starting at 200 mg/kg body weight (p=0.000. CONCLUSION Ethanolic extract of Garcinia mangostana pericarp has a beneficial effect on lipid profile in rats on a high lipid diet.

US program for the immobilization of high-level nuclear wastes

International Nuclear Information System (INIS)

Crandall, J.L.

1979-01-01

A program has been developed for long-term management of high-level nuclear waste. The Savannah River Operations Office of the US Department of Energy is acting as the lead office for this program with technical advice from the E.I. du Pont de Nemours and Company. The purpose of the long-term program is to immobilize the DOE high-level waste in forms that act as highly efficient barriers against radionuclide release to the disposal site and to provide technology for similar treatment of commercial high-level waste in case reprocessing of commercial nuclear fuels is ever resumed. Descriptions of existing DOE and commercial wastes, program strategy, program expenditures, development of waste forms, evaluation and selection of waste forms, regulatory aspects of waste form selection, project schedules, and cost estimates for immobilization facilities are discussed

Reachability Trees for High-level Petri Nets

DEFF Research Database (Denmark)

Jensen, Kurt; Jensen, Arne M.; Jepsen, Leif Obel

1986-01-01

the necessary analysis methods. In other papers it is shown how to generalize the concept of place- and transition invariants from place/transition nets to high-level Petri nets. Our present paper contributes to this with a generalization of reachability trees, which is one of the other important analysis...

Chromosome Aberration on High Level Background Natural Radiation Areas

International Nuclear Information System (INIS)

Yanti-Lusiyanti; Zubaidah-Alatas

2001-01-01

When the body is irradiated, all cells can suffer cytogenetic damage that can be seen as structural damage of chromosome in the lymphocytes. People no matter where they live in world are exposed to background radiation from natural sources both internal and external such as cosmic radiation, terrestrial radiation, cosmogenic radiation radon and thoron. Level of area natural ionizing radiation is varies depending on the altitude, the soil or rock conditions, particular food chains and the building materials and construction features. Level of normal areas of background exposure is annual effective dose 2.4 mSv and the high level areas of background exposure 20 mSv. This paper discuses the frequency of aberration chromosome especially dysenteries in several countries having high level radiation background. It seems that frequency of chromosome aberrations increase, generally with the increase of age of the people and the accumulated dose received. (author)

Design features of a full-scale high-level waste vitrification system

International Nuclear Information System (INIS)

Siemens, D.H.; Bonner, W.F.

1976-08-01

A system has been designed and is currently under construction for vitrification of commercial high-level waste. The process consists of a spray calciner coupled to an in-can melter. Due to the high radiation levels expected, this equipment is designed for totally remote operation and maintenance. The in-cell arrangement of this equipment has been developed cooperatively with a nuclear fuel reprocessor. The system will be demonstrated both full scale with nonradioactive simulated waste and pilot scale with actual high-level waste

Proteasome activity related with the daily physical activity of COPD patients

Directory of Open Access Journals (Sweden)

Lee KY

2017-05-01

.01, and 6MWD (r=-0.313, P<0.05 in COPD patients. Our results showed no significant difference in inflammatory markers (interleukin-6 and tumor necrosis factor-α or ubiquitin between the two groups.Conclusion: COPD patients had lower DPA levels and higher circulating proteasome activity than HSs, and a negative correlation of DPA with circulating proteasome activity. Keywords: chronic obstructive pulmonary disease, circulating proteasome, daily physical activity, protein carbonyl, anthropometric indicator

Radiation damage simulation studies of selected austenitic and ferritic/martensitic alloys for fusion reactor structural applications

International Nuclear Information System (INIS)

Mazey, D.J.; Walters, G.P.; Buckley, S.N.; Bullough, R.; Hanks, W.; Bolster, D.E.J.; Sowden, B.C.; Lurcook, D.; Murphy, S.M.

1985-03-01

Results are given of an investigation of the radiation damage stability of selected austenitic and ferritic alloys following ion bombardment in the Harwell VEC to simulate fusion-reactor exposures up to 110 dpa at temperatures from 425 deg to 625 deg C. Gas production rates appropriate to CTR conditions were simulated using a mixed beam of (4 MeV He + 2 MeV H 2 ) in the ratio 1:4 He:H. A beam of 46 MeV Ni or 20 MeV Cr ions was used in sequence with the mixed gas beam to provide a gas/damage ratio of 13 appm He/dpa at a damage rate of approx. 1 dpa/hr. The materials were investigated using TEM and comprised three austenitic alloys: European reference 316L, 316-Ti, 316-Nb; four high-nickel alloys: Fe/25 Ni/8Cr, Inconel 625, Inconel 706 and Nimonic PE16, and four ferritic/martensitic alloys: FV 448, FV 607, CRM 12 and FI. Some data were obtained for a non-magnetic structural alloy Nonmagne-30. The swelling behaviour is reported. The overall results of the study indicate that on a comparative basis the ferritic alloys are the most swelling-resistant, whilst the high-nickel alloys have an acceptable low swelling response up to 110 dpa. The 316 alloys tested have shown an unfavourable swelling response. (author)

Assessment of studies and researches on warehousing - High-level and intermediate-level-long-lived radioactive wastes - December 2012

International Nuclear Information System (INIS)

2013-01-01

This large report first presents the approach adopted for the study and research on the warehousing of high-level and intermediate-level-long-lived radioactive wastes. It outlines how reversible storage and warehousing are complementary, discusses the lessons learned from researches performed by the CEA on long duration warehousing, presents the framework of studies and researches performed since 2006, and presents the scientific and technical content of studies and researches (warehousing need analysis, search for technical options providing complementarity with storage, extension or creation of warehousing installations). The second part addresses high-level and intermediate-level-long-lived radioactive waste parcels, indicates their origins and quantities. The third part proposes an analysis of warehousing capacities: existing capacities, French industrial experience in waste parcel warehousing, foreign experience in waste warehousing. The fourth part addresses reversible storage in deep geological formation: storage safety functions, storage reversibility, storage parcels, storage architecture, chronicle draft. The fifth part proposes an inventory of warehousing needs in terms of additional capacities for the both types of wastes (high-level, and intermediate-level-long-lived), and discusses warehousing functionalities and safety objectives. The sixth and seventh parts propose a detailed overview of design options for warehousing installations, respectively for high-level and for intermediate-level-long-lived waste parcels: main technical issues, feasibility studies of different concepts or architecture shapes, results of previous studies and introduction to studies performed since 2011, possible evolutions of the HA1, HA2 and MAVL concepts. The eighth chapter reports a phenomenological analysis of warehousing and the optimisation of material selection and construction arrangements. The last part discusses the application of researches to the extension of the

Management of high level radioactive waste

International Nuclear Information System (INIS)

Redon, A.; Mamelle, J.; Chambon, M.

1977-01-01

The world wide needs in reprocessing will reach the value of 10.000 t/y of irradiated fuels, in the mid of the 80's. Several countries will have planned, in their nuclear programme, the construction of reprocessing plants with a 1500 t/y capacity, corresponding to 50.000 MWe installed. At such a level, the solidification of the radioactive waste will become imperative. For this reason, all efforts, in France, have been directed towards the realization of industrial plants able of solidifying the fission products as a glassy material. The advantages of this decision, and the reasons for it are presented. The continuing development work, and the conditions and methods of storing the high-level wastes prior to solidification, and of the interim storage (for thermal decay) and the ultimate disposal after solidification are described [fr

Development of melt compositions for sulphate bearing high level waste

International Nuclear Information System (INIS)

Jahagirdar, P.B.; Wattal, P.K.

1997-09-01

The report deals with the development and characterization of vitreous matrices for sulphate bearing high level waste. Studies were conducted in sodium borosilicate and lead borosilicate systems with the introduction of CaO, BaO, MgO etc. Lead borosilicate system was found to be compatible with sulphate bearing high level wastes. Detailed product evaluation carried on selected formulations is also described. (author)

Decision Document for Heat Removal from High-Level Waste Tanks

International Nuclear Information System (INIS)

WILLIS, W.L.

2000-01-01

This document establishes the combination of design and operational configurations that will be used to provide heat removal from high-level waste tanks during Phase 1 waste feed delivery to prevent the waste temperature from exceeding tank safety requirement limits. The chosen method--to use the primary and annulus ventilation systems to remove heat from the high-level waste tanks--is documented herein

Experience and results of material science research conducted on spent fuel assemblies from the BN-350 fast reactor

Energy Technology Data Exchange (ETDEWEB)

Maksimkin, O.; Gusev, M.; Turubarova, L.G.; Tsai, K.V.; Yarovchuk, A.V. [Institute of Nuclear Physics, Almaty (Kazakhstan)

2007-07-01

Full text of publication follows: The BN-350 fast reactor was commissioned in 1973, ran successfully for many years and is now in the decommission stage. Its unique operational parameters (low temperature of sodium at the input, wide range of damage rates, etc. ) allowed the investigation of a number of new radiation effects on both austenitic and ferritic-martensitic steels. The latter class of steel was extensively employed as wrappers for fuel assemblies. Much of the accumulated experience in BN-350 is relevant to development of fusion devices. Results are presented on post-operational research of steels 12Cr18Ni10Ti, 08Cr16Ni11Mo3, and 12Cr13Mo2BFR, all serving as hexagonal shrouds of fuel assemblies. Structural materials in the active core zone operated at temperatures of 280-430 deg. C, and were irradiated the range of 0.25-83 dpa with damage rates of 10{sup -9} - 10{sup -6} dpa/s). Investigations of irradiated hexagonal shroud materials were performed with using traditional techniques of transmission and scanning electron microscopy, metallography, mechanical tests, hydrostatic weighing, magnetometry, etc. Additionally, new techniques have been developed and employed with great success on these highly irradiated materials, such as optical computer extensometry, and magnetization cartography. Typical results to be covered in this presentation are: a) In 12Cr18Ni10Ti steel irradiated at a low dose rate of 0.12 x 10{sup -8} dpa/s voids were found at 281 deg. C after only 0.65 dpa, demonstrating once again the acceleration of swelling at low dpa rates observed in other steels. b) Data on helium release during annealing of highly irradiated sample are presented. c) Differences in deformation-induced hardening between the shroud's corners and faces leads to post-irradiation differences in swelling and mechanical properties. d) During room temperature mechanical tests of 12Cr18Ni10Ti steel at {approx}56 dpa at 350 deg. C it was found that ductility lost at

Future directions of defense programs high-level waste technology programs

International Nuclear Information System (INIS)

Chee, T.C.; Shupe, M.W.; Turner, D.A.; Campbell, M.H.

1987-01-01

The Department of Energy has been managing high-level waste from the production of nuclear materials for defense activities over the last forty years. An objective for the Defense Waste and Transportation Management program is to develop technology which ensures the safe, permanent disposal of all defense radioactive wastes. Technology programs are underway to address the long-term strategy for permanent disposal of high-level waste generated at each Department of Energy site. Technology is being developed for assessing the hazards, environmental impacts, and costs of each long-term disposal alternative for selection and implementation. This paper addresses key technology development areas, and consideration of recent regulatory requirements associated with the long-term management of defense radioactive high-level waste

High-level radioactive waste disposal type and theoretical analyses

International Nuclear Information System (INIS)

Lu Yingfa; Wu Yanchun; Luo Xianqi; Cui Yujun

2006-01-01

Study of high-level radioactive waste disposal is necessary for the nuclear electrical development; the determination of nuclear waste depository type is one of importance safety. Based on the high-level radioactive disposal type, the relative research subjects are proposed, then the fundamental research characteristics of nuclear waste disposition, for instance: mechanical and hydraulic properties of rock mass, saturated and unsaturated seepage, chemical behaviors, behavior of special soil, and gas behavior, etc. are introduced, the relative coupling equations are suggested, and a one dimensional result is proposed. (authors)

Abscisic acid metabolite profiling as indicators of plastic responses to drought in grasses from arid Patagonian Monte (Argentina).

Science.gov (United States)

Cenzano, Ana M; Masciarelli, O; Luna, M Virginia

2014-10-01

The identification of hormonal and biochemical traits that play functional roles in the adaptation to drought is necessary for the conservation and planning of rangeland management. The aim of this study was to evaluate the effects of drought on i) the water content (WC) of different plant organs, ii) the endogenous level of abscisic acid (ABA) and metabolites (phaseic acid-PA, dihydrophaseic acid-DPA and abscisic acid conjugated with glucose ester-ABA-GE), iii) the total carotenoid concentration and iv) to compare the traits of two desert perennial grasses (Pappostipa speciosa and Poa ligularis) with contrasting morphological and functional drought resistance traits and life-history strategies. Both species were subjected to two levels of gravimetric soil moisture (the highest near field capacity during autumn-winter and the lowest corresponding to summer drought). Drought significantly increased the ABA and DPA levels in the green leaves of P. speciosa and P. ligularis. Drought decreased ABA in the roots of P. speciosa while it increased ABA in the roots of P. ligularis. P. ligularis had the highest ABA level and WC in green leaves. While P. speciosa had the highest DPA levels in leaves. In conclusion, we found the highest ABA level in the mesophytic species P. ligularis and the lowest ABA level in the xerophytic species P. speciosa, revealing that the ABA metabolite profile in each grass species is a plastic response to drought resistance. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

The ATLAS high level trigger region of interest builder

International Nuclear Information System (INIS)

Blair, R.; Dawson, J.; Drake, G.; Haberichter, W.; Schlereth, J.; Zhang, J.; Ermoline, Y.; Pope, B.; Aboline, M.; High Energy Physics; Michigan State Univ.

2008-01-01

This article describes the design, testing and production of the ATLAS Region of Interest Builder (RoIB). This device acts as an interface between the Level 1 trigger and the high level trigger (HLT) farm for the ATLAS LHC detector. It distributes all of the Level 1 data for a subset of events to a small number of (16 or less) individual commodity processors. These processors in turn provide this information to the HLT. This allows the HLT to use the Level 1 information to narrow data requests to areas of the detector where Level 1 has identified interesting objects

Some legal aspects on high level radioactive waste disposal in Japan

International Nuclear Information System (INIS)

Tanabe, Tomoyuki

1997-01-01

In Japan, it is considered to be an urgent problem to prepare the system for the research and execution of high level radioactive waste disposal. Under what regulation scheme the disposal should be done has not been sufficiently examined. In this research, the examination was carried out on the legal aspects of high level radioactive waste disposal as follows. First, the current legislation on the disposal in Japan was analyzed, and it was made clear that high level radioactive waste disposal has not been stipulated clearly. Next, on the legal choices which are conceivable on the way the legislation for high level radioactive waste disposal should be, from the aspects of applying the law on regulating nuclear reactors and others, applying the law on nuclear power damage reparation, and industrialization by changing the government ordinances, those were arranged in six choices, and the examination was carried out for each choice from the viewpoints of the relation with the base stipulation for waste-burying business, the speciality of high level radioactive waste disposal as compared with other actions of nuclear power business, the coordination with existing nuclear power of nuclear power business, the coordination with existing nuclear power law system and the formation of national consensus. In this research, it was shown that the execution of high level radioactive waste disposal as the business based on the separate legislation is the realistic choice. (K.I.)

Tensile and charpy impact properties of irradiated reduced-activation ferritic steels

Energy Technology Data Exchange (ETDEWEB)

Klueh, R.L.; Alexander, D.J. [Oak Ridge National Lab., TN (United States)

1996-10-01

Tensile tests were conducted on eight reduced-activation Cr-W steels after irradiation to 15-17 and 26-29 dpa, and Charpy impact tests were conducted on the steels irradiated to 26-29 dpa. Irradiation was in the Fast Flux Test Facility at 365{degrees}C on steels containing 2.25-12% Cr, varying amounts of W, V, and Ta, and 0.1%C. Previously, tensile specimens were irradiated to 6-8 dpa and Charpy specimens to 6-8, 15-17, and 20-24 dpa. Tensile and Charpy specimens were also thermally aged to 20000 h at 365{degrees}C. Thermal aging had little effect on the tensile behavior or the ductile-brittle transition temperature (DBTT), but several steels showed a slight increase in the upper-shelf energy (USE). After {approx}7 dpa, the strength of the steels increased and then remained relatively unchanged through 26-29 dpa (i.e., the strength saturated with fluence). Post-irradiation Charpy impact tests after 26-29 dpa showed that the loss of impact toughness, as measured by an increase in DBTT and a decrease in the USE, remained relatively unchanged from the values after 20-24 dpa, which had been relatively unchanged from the earlier irradiations. As before, the two 9Cr steels were the most irradiation resistant.

CMS High Level Trigger Timing Measurements

International Nuclear Information System (INIS)

Richardson, Clint

2015-01-01

The two-level trigger system employed by CMS consists of the Level 1 (L1) Trigger, which is implemented using custom-built electronics, and the High Level Trigger (HLT), a farm of commercial CPUs running a streamlined version of the offline CMS reconstruction software. The operational L1 output rate of 100 kHz, together with the number of CPUs in the HLT farm, imposes a fundamental constraint on the amount of time available for the HLT to process events. Exceeding this limit impacts the experiment's ability to collect data efficiently. Hence, there is a critical need to characterize the performance of the HLT farm as well as the algorithms run prior to start up in order to ensure optimal data taking. Additional complications arise from the fact that the HLT farm consists of multiple generations of hardware and there can be subtleties in machine performance. We present our methods of measuring the timing performance of the CMS HLT, including the challenges of making such measurements. Results for the performance of various Intel Xeon architectures from 2009-2014 and different data taking scenarios are also presented. (paper)

Biosynthesis of dipicolinic acid in Clostridium roseum

Energy Technology Data Exchange (ETDEWEB)

Prakasan, K. (Paraiba Univ., Joao Pessoa (Brazil)); Sharma, D. (Gobind Ballabh Pant Univ. of Agriculture and Technology, Nainital (India))

1981-02-01

Dipicolinic acid (DPA) synthesis was studied in Clostridium roseum by permitting the organism to complete vegetative growth in trypticase medium and trasfering the cells to a non-growth-promoting-medium, supplemented with the appropriate /sup 14/C-labelled precursors to complete sporulation and assaying the incorporation of label into DPA. Glu, asp, ala, ser and acetate were found to be efficient precursors of DPA and each one influenced the incorporation of other into DPA. The data suggest that a C/sub 5/ precursor is being trasformed into a C/sub 4/ intermediate, and a C/sub 2/ precursor into a C/sub 4/ intermediate, before their entry into DPA carbon structure. A C/sub 4/ plus C/sub 3/ condensation is favoured over C/sub 5/ plus C/sub 2/ or other condensation in the DPA biosynthesis.

Experiences in messaging middle-ware for high-level control applications

International Nuclear Information System (INIS)

Wanga, N.; Shasharina, S.; Matykiewicz, J.; Rooparani Pundaleeka

2012-01-01

Existing high-level applications in accelerator control and modeling systems leverage many different languages, tools and frameworks that do not inter-operate with one another. As a result, the accelerator control community is moving toward the proven Service-Oriented Architecture (SOA) approach to address the inter-operability challenges among heterogeneous high-level application modules. Such SOA approach enables developers to package various control subsystems and activities into 'services' with well-defined 'interfaces' and make leveraging heterogeneous high-level applications via flexible composition possible. Examples of such applications include presentation panel clients based on Control System Studio (CSS) and middle-layer applications such as model/data servers. This paper presents our experiences in developing a demonstrative high-level application environment using emerging messaging middle-ware standards. In particular, we utilize new features in EPICS v4 and other emerging standards such as Data Distribution Service (DDS) and Extensible Type Interface by the Object Management Group. We first briefly review examples we developed previously. We then present our current effort in integrating DDS into such a SOA environment for control systems. Specifically, we illustrate how we are integrating DDS into CSS and develop a Python DDS mapping. (authors)

Ultrasonic level sensors for liquids under high pressure

Science.gov (United States)

Zuckerwar, A. J.; Mazel, D. S.; Hodges, D. Y.

1986-01-01

An ultrasonic level sensor of novel design continuously measures the level of a liquid subjected to a high pressure (up to about 40 MPa), as is sometimes required for the effective transfer of the liquid. The sensor operates as a composite resonator fabricated from a standard high-pressure plug. A flat-bottom hole is machined into the plug along its center line. An ultrasonic transducer is bonded rigidly to the interior surface of the bottom wall, while the exterior surface is in contact with the liquid. Although the bottom wall is designed to satisfy the pressure code, it is still sufficiently thin to permit ready excitation of the axisymmetric plate modes of vibration. The liquid level is measured by a conventional pulse-echo technique. A prototype sensor was tested successfully in a 2300-l water vessel at pressures up to about 37 MPa. A spectral analysis of the transmitted pulse reveals that the flexural, extensional, thickness-shear, and radial plate modes are excited into vibration, but none of these appears to be significantly affected by the pressurization of the liquid.

Biosynthethesis of dipicolinic acid in Clostridium roseum

International Nuclear Information System (INIS)

Prakasan, K.M.; Sharma, D.; Gollakota, K.G.; Lakechaura, B.D.

1975-01-01

Dipicolinic acid (DPA) is a major constituent of bacterial endospores and the thermal resistance of spores is closely correlated with their calcium dipicolinate content. The biosynthesis of DPA in anaerobes was studied in Cl. roseum using the technique of endotrophic sporulation. The cells from the complex medium were harvested at a stage when they were refractile and stainable, resuspended in nongrowth promoting mineral water supplemented with radioactive presumptive precursors of DPA and incubated. The incorporation in DPA of exogenously supplied individual metabolites was followed by radioactictivity (C 14 ) measurements. Glutamic acid, aspartic acid, alanine, serine, and acetate were found efficient precursors of DPA. (author)

Standards for high level waste disposal: A sustainability perspective

International Nuclear Information System (INIS)

Dougherty, W.W.; Powers, V.; Johnson, F.X.; Cornland, D.

1999-01-01

Spent reactor fuel from commercial power stations contains high levels of plutonium, other fissionable actinides, and fission products, all of which pose serious challenges for permanent disposal because of the very long half-lives of some isotopes. The 'nuclear nations' have agreed on the use of permanent geologic repositories for the ultimate disposal of high-level nuclear waste. However, it is premature to claim that a geologic repository offers permanent isolation from the biosphere, given high levels of uncertainty, nascent risk assessment frameworks for the time periods considered, and serious intergenerational equity issues. Many have argued for a broader consideration of disposal options that include extended monitored retrievable storage and accelerator-driven transmutation of wastes. In this paper we discuss and compare these three options relative to standards that emerge from the application of sustainable development principles, namely long-lasting technical viability, intergenerational equity, rational resource allocation, and rights of future intervention. We conclude that in order to maximise the autonomy of future generations, it is imperative to leave future options more open than does permanent disposal

Neural Networks Mediating High-Level Mentalizing in Patients With Right Cerebral Hemispheric Gliomas

Directory of Open Access Journals (Sweden)

Riho Nakajima

2018-03-01

Full Text Available Mentalizing is the ability to understand others’ mental state through external cues. It consists of two networks, namely low-level and high-level metalizing. Although it is an essential function in our daily social life, surgical resection of right cerebral hemisphere disturbs mentalizing processing with high possibility. In the past, little was known about the white matter related to high-level mentalizing, and the conservation of high-level mentalizing during surgery has not been a focus of attention. Therefore, the main purpose of this study was to examine the neural networks underlying high-level mentalizing and then, secondarily, investigate the usefulness of awake surgery in preserving the mentalizing network. A total of 20 patients with glioma localized in the right hemisphere who underwent awake surgery participated in this study. All patients were assigned to two groups: with or without intraoperative assessment of high-level mentalizing. Their high-level mentalizing abilities were assessed before surgery and 1 week and 3 months after surgery. At 3 months after surgery, only patients who received the intraoperative high-level mentalizing test showed the same score as normal healthy volunteers. The tract-based lesion symptom analysis was performed to confirm the severity of damage of associated fibers and high-level mentalizing accuracy. This analysis revealed the superior longitudinal fascicles (SLF III and fronto-striatal tract (FST to be associated with high-level mentalizing processing. Moreover, the voxel-based lesion symptom analysis demonstrated that resection of orbito-frontal cortex (OFC causes persistent mentalizing dysfunction. Our study indicates that damage of the OFC and structural connectivity of the SLF and FST causes the disorder of mentalizing after surgery, and assessing high-level mentalizing during surgery may be useful to preserve these pathways.

Proposed classification scheme for high-level and other radioactive wastes

International Nuclear Information System (INIS)

Kocher, D.C.; Croff, A.G.

1986-01-01

The Nuclear Waste Policy Act (NWPA) of 1982 defines high-level radioactive waste (HLW) as: (A) the highly radioactive material resulting from the reprocessing of spent nuclear fuel....that contains fission products in sufficient concentrations; and (B) other highly radioactive material that the Commission....determines....requires permanent isolation. This paper presents a generally applicable quantitative definition of HLW that addresses the description in paragraph (B). The approach also results in definitions of other waste classes, i.e., transuranic (TRU) and low-level waste (LLW). A basic waste classification scheme results from the quantitative definitions

Theoretical Investigations of CO 2 and H 2 Sorption in an Interpenetrated Square-Pillared Metal–Organic Material

KAUST Repository

Pham, Tony

2013-05-16

Simulations of CO2 and H2 sorption and separation were performed in [Cu(dpa)2SiF6-i], a metal-organic material (MOM) consisting of an interpenetrated square grid of Cu2+ ions coordinated to 4,4′-dipyridylacetylene (dpa) rings and pillars of SiF6 2- ions. This class of water stable MOMs shows great promise in practical gas sorption/separation with especially high selectivity for CO2 and variable selectivity for other energy related gases. Simulated CO2 sorption isotherms and isosteric heats of adsorption, Qst, at ambient temperatures were in excellent agreement with the experimental measurements at all pressures considered. Further, it was observed that the Qst for CO2 increases as a function of uptake in [Cu(dpa)2SiF6-i]. This suggests that nascently sorbed CO2 molecules within a channel contribute to a more energetically favorable site for additional CO2 molecules, i.e., in stark contrast to typical behavior, sorbate intermolecular interactions enhance sorption energetics with increased loading. The simulated structure at CO2 saturation shows a loading with tight packing of 8 CO2 molecules per unit cell. The CO2 molecules can be seen alternating between a vertical and horizontal alignment within a channel, with each CO2 molecule coordinating to an equatorial fluorine MOM atom. Calculated H 2 sorption isotherms and Qst values were also in good agreement with the experimental measurements in [Cu(dpa)2SiF 6-i]. H2 saturation corresponds to 10 H2 molecules per unit cell for the studied structure. Moreover, there were two observed binding sites for hydrogen sorption in [Cu(dpa)2SiF 6-i]. Simulations of a 30:70 CO2/H2 mixture, typical of syngas, in [Cu(dpa)2SiF6-i] showed that the MOM exhibited a high uptake and selectivity for CO2. In addition, it was observed that the presence of H2O had a negligible effect on the CO2 uptake and selectivity in [Cu(dpa)2SiF6-i], as simulations of a mixture containing CO2, H2, and small amounts of CO, N2, and H2O produced comparable

DUACS: Toward High Resolution Sea Level Products

Science.gov (United States)

Faugere, Y.; Gerald, D.; Ubelmann, C.; Claire, D.; Pujol, M. I.; Antoine, D.; Desjonqueres, J. D.; Picot, N.

2016-12-01

The DUACS system produces, as part of the CNES/SALP project, and the Copernicus Marine Environment and Monitoring Service, high quality multimission altimetry Sea Level products for oceanographic applications, climate forecasting centers, geophysic and biology communities... These products consist in directly usable and easy to manipulate Level 3 (along-track cross-calibrated SLA) and Level 4 products (multiple sensors merged as maps or time series) and are available in global and regional version (Mediterranean Sea, Arctic, European Shelves …).The quality of the products is today limited by the altimeter technology "Low Resolution Mode" (LRM), and the lack of available observations. The launch of 2 new satellites in 2016, Jason-3 and Sentinel-3A, opens new perspectives. Using the global Synthetic Aperture Radar mode (SARM) coverage of S3A and optimizing the LRM altimeter processing (retracking, editing, ...) will allow us to fully exploit the fine-scale content of the altimetric missions. Thanks to this increase of real time altimetry observations we will also be able to improve Level-4 products by combining these new Level-3 products and new mapping methodology, such as dynamic interpolation. Finally these improvements will benefit to downstream products : geostrophic currents, Lagrangian products, eddy atlas… Overcoming all these challenges will provide major upgrades of Sea Level products to better fulfill user needs.

Key scientific challenges in geological disposal of high level radioactive waste

International Nuclear Information System (INIS)

Wang Ju

2007-01-01

The geological disposal of high radioactive waste is a challenging task facing the scientific and technical world. This paper introduces the latest progress of high level radioactive disposal programs in the latest progress of high level radioactive disposal programs in the world, and discusses the following key scientific challenges: (1) precise prediction of the evolution of a repository site; (2) characteristics of deep geological environment; (3) behaviour of deep rock mass, groundwater and engineering material under coupled con-ditions (intermediate to high temperature, geostress, hydraulic, chemical, biological and radiation process, etc); (4) geo-chemical behaviour of transuranic radionuclides with low concentration and its migration with groundwater; and (5) safety assessment of disposal system. Several large-scale research projects and several hot topics related with high-level waste disposal are also introduced. (authors)

Preparation of 2H- and 3H-labeled phaseic acid and dihydrophaseic acid as standards for determination of abscisic acid metabolites in tomato fruit

International Nuclear Information System (INIS)

Kubik, M.; Buta, J.G.

1990-01-01

There have been reports that the level of abscisic acid (ABA) increases during the cold storage of tomatoes. However, the important ABA metabolites, phaseic acid (PA) and dihydrophaseic acid (DPA) were never quantitatively determined in such a system. In order to obtain the labeled standards for quantitative determination of those compounds by GC-MS-SIM, we fed bean plants with 6,6,6-[ 2 H 3 ]-ABA (mean isotopic enrichment 60%) with addition of about 10 5 Bq per mg of [ 3 H]-ABA. After 100 hours the plants were harvested and extracted with acetone. The extract were purified by solvent partitioning and, Prep-Sep amino column and on an HPLC C 18 reverse phase column. Two major radioactive metabolites of ABA were obtained and identified by GC-MS as PA and DPA. Some results on the quantitation of ABA, PA and DPA in tomato fruit after cold storage will be presented

Parity dependence of the nuclear level density at high excitation

International Nuclear Information System (INIS)

Rao, B.V.; Agrawal, H.M.

1995-01-01

The basic underlying assumption ρ(l+1, J)=ρ(l, J) in the level density function ρ(U, J, π) has been checked on the basis of high quality data available on individual resonance parameters (E 0 , Γ n , J π ) for s- and p-wave neutrons in contrast to the earlier analysis where information about p-wave resonance parameters was meagre. The missing level estimator based on the partial integration over a Porter-Thomas distribution of neutron reduced widths and the Dyson-Mehta Δ 3 statistic for the level spacing have been used to ascertain that the s- and p-wave resonance level spacings D(0) and D(1) are not in error because of spurious and missing levels. The present work does not validate the tacit assumption ρ(l+1, J)=ρ(l, J) and confirms that the level density depends upon parity at high excitation. The possible implications of the parity dependence of the level density on the results of statistical model calculations of nuclear reaction cross sections as well as on pre-compound emission have been emphasized. (orig.)

High-Level Synthesis: Productivity, Performance, and Software Constraints

Directory of Open Access Journals (Sweden)

Yun Liang

2012-01-01

Full Text Available FPGAs are an attractive platform for applications with high computation demand and low energy consumption requirements. However, design effort for FPGA implementations remains high—often an order of magnitude larger than design effort using high-level languages. Instead of this time-consuming process, high-level synthesis (HLS tools generate hardware implementations from algorithm descriptions in languages such as C/C++ and SystemC. Such tools reduce design effort: high-level descriptions are more compact and less error prone. HLS tools promise hardware development abstracted from software designer knowledge of the implementation platform. In this paper, we present an unbiased study of the performance, usability and productivity of HLS using AutoPilot (a state-of-the-art HLS tool. In particular, we first evaluate AutoPilot using the popular embedded benchmark kernels. Then, to evaluate the suitability of HLS on real-world applications, we perform a case study of stereo matching, an active area of computer vision research that uses techniques also common for image denoising, image retrieval, feature matching, and face recognition. Based on our study, we provide insights on current limitations of mapping general-purpose software to hardware using HLS and some future directions for HLS tool development. We also offer several guidelines for hardware-friendly software design. For popular embedded benchmark kernels, the designs produced by HLS achieve 4X to 126X speedup over the software version. The stereo matching algorithms achieve between 3.5X and 67.9X speedup over software (but still less than manual RTL design with a fivefold reduction in design effort versus manual RTL design.

Subseasonal to Seasonal Predictions of U.S. West Coast High Water Levels

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Khouakhi, A.; Villarini, G.; Zhang, W.; Slater, L. J.

2017-12-01

Extreme sea levels pose a significant threat to coastal communities, ecosystems, and assets, as they are conducive to coastal flooding, coastal erosion and inland salt-water intrusion. As sea levels continue to rise, these sea level extremes - including occasional minor coastal flooding experienced during high tide (nuisance floods) - are of concern. Extreme sea levels are increasing at many locations around the globe and have been attributed largely to rising mean sea levels associated with intra-seasonal to interannual climate processes such as the El Niño-Southern Oscillation (ENSO). Here, intra-seasonal to seasonal probabilistic forecasts of high water levels are computed at the Toke Point tide gage station on the US west coast. We first identify the main climate drivers that are responsible for high water levels and examine their predictability using General Circulation Models (GCMs) from the North American Multi-Model Ensemble (NMME). These drivers are then used to develop a probabilistic framework for the seasonal forecasting of high water levels. We focus on the climate controls on the frequency of high water levels using the number of exceedances above the 99.5th percentile and above the nuisance flood level established by the National Weather Service. Our findings indicate good forecast skill at the shortest lead time, with the skill that decreases as we increase the lead time. In general, these models aptly capture the year-to-year variability in the observational records.