The influence of transition metal solutes on dislocation core structure and values of Peierls stress and barrier in tungsten

Several transition metals were examined to evaluate their potential for improving the ductility of tungsten. The dislocation core structure and Peierls stress and barrier of $1/2$ screw dislocations in binary tungsten-transition metal alloys (W$_{1-x}$TM$_{x}$) were investigated using first principles electronic structure calculations. The periodic quadrupole approach was applied to model the structure of $1/2$ dislocation. Alloying with transition metals was modeled using the virtual crystal approximation and the applicability of this approach was assessed by calculating the equilibrium lattice parameter and elastic constants of the tungsten alloys. Reasonable agreement was obtained with experimental data and with results obtained from the conventional supercell approach. Increasing the concentration of a transition metal from the VIIIA group, i.e. the elements in columns headed by Fe, Co and Ni, leads to reduction of the $C^\prime$ elastic constant and increase of elastic anisotropy A=$C_{44}/C^\prime$. Alloying W with a group VIIIA transition metal changes the structure of the dislocation core from symmetric to asymmetric, similar to results obtained for W$_{1-x}$Re$_{x}$ alloys in the earlier work of Romaner {\it et al} (Phys. Rev. Lett. 104, 195503 (2010))\comments{\cite{WRECORE}}. In addition to a change in the core symmetry, the values of the Peierls stress and barrier are reduced. The latter effect could lead to increased ductility in a tungsten-based alloy\comments{\cite{WRECORE}}. Our results demonstrate that alloying with any of the transition metals from the VIIIA group should have similar effect as alloying with Re.Comment: 12 pages, 8 figures, 3 table

Ultrahigh Surface Area Three-Dimensional Porous Graphitic Carbon from Conjugated Polymeric Molecular Framework

Porous graphitic carbon is essential for many applications such as energy storage devices, catalysts, and sorbents. However, current graphitic carbons are limited by low conductivity, low surface area, and ineffective pore structure. Here we report a scalable synthesis of porous graphitic carbons using a conjugated polymeric molecular framework as precursor. The multivalent cross-linker and rigid conjugated framework help to maintain micro- and mesoporous structures, while promoting graphitization during carbonization and chemical activation. The above unique design results in a class of highly graphitic carbons at temperature as low as 800 ??C with record-high surface area (4073 m2 g-1), large pore volume (2.26 cm-3), and hierarchical pore architecture. Such carbons simultaneously exhibit electrical conductivity >3 times more than activated carbons, very high electrochemical activity at high mass loading, and high stability, as demonstrated by supercapacitors and lithium-sulfur batteries with excellent performance. Moreover, the synthesis can be readily tuned to make a broad range of graphitic carbons with desired structures and compositions for many applications.clos

Measurements of atmospheric layers from the NASA DC-8 and P-3B aircraft during PEM-Tropics A

Tropospheric vertical structure was analyzed using in situ measurements of O₃, CO, CH₄, and H₂O taken on board the NASA DC-8 aircraft during three Pacific Exploratory Missions (PEMs): PEM-West A, September-October 1991 in the western Pacific; PEM-West B, February-March 1994 in the western Pacific; and PEM-Tropics A, September-October 1996 in the central and eastern Pacific. PEM-Tropics A added measurements from the NASA P3-B aircraft. We used a new mode-based method to define a background against which to find layers. Using only O₃ and H₂O, we found 472 layers in PEM-Tropics A (0.72 layers per vertical kilometer profiled), 237 layers in PEM-West A (0.54 layers/km), and 158 layers in PEM-West B (0.41 layers/km). Using all constituents, we found 187 layers in PEM-Tropics A (0.43 layers/km), 128 layers in PEM-West A (0.29 layers/km), and 80 layers in PEM-West B (0.21 layers/km). Stratospheric air, sometimes mixed with trapped pollution, was the dominant layer source in all three missions. The larger number of layers per kilometer in PEM-Tropics A was probably due to repeated profiling of several “superlayers” visible in many of the mission lidar and potential voracity profiles. The thickness of the superlayers was of order 1 km, and the horizontal extent was of order 1000 km. We found that layers have an important effect on the thermal structure. An example based on ozonesonde data from Tahiti is shown, where a dry, subsiding layer was stabilized by much greater radiative cooling at the base than at the top. The stabilized layer can trap pollution and force vertical plumes to spread into horizontal layers.United States. National Aeronautics and Space Administration (Grant NAG1-1758)United States. National Aeronautics and Space Administration (Grant NAG1-1901

Relativistic Calculation of two-Electron one-Photon and Hypersatellite Transition Energies for 12≤Z≤3012\leq Z\leq30 Elements

Energies of two-electron one-photon transitions from initial double K-hole states were computed using the Dirac-Fock model. The transition energies of competing processes, the K$\alpha$ hypersatellites, were also computed. The results are compared to experiment and to other theoretical calculations.Comment: accepted versio

Reliability of Measurements Performed by Community-Drawn Anthropometrists from Rural Ethiopia

Undernutrition is an important risk factor for childhood mortality, and remains a major problem facing many developing countries. Millennium Development Goal 1 calls for a reduction in underweight children, implemented through a variety of interventions. To adequately judge the impact of these interventions, it is important to know the reproducibility of the main indicators for undernutrition. In this study, we trained individuals from rural communities in Ethiopia in anthropometry techniques and measured intra- and inter-observer reliability.We trained 6 individuals without prior anthropometry experience to perform weight, height, and middle upper arm circumference (MUAC) measurements. Two anthropometry teams were dispatched to 18 communities in rural Ethiopia and measurements performed on all consenting pre-school children. Anthropometry teams performed a second independent measurement on a convenience sample of children in order to assess intra-anthropometrist reliability. Both teams measured the same children in 2 villages to assess inter-anthropometrist reliability. We calculated several metrics of measurement reproducibility, including the technical error of measurement (TEM) and relative TEM. In total, anthropometry teams performed measurements on 606 pre-school children, 84 of which had repeat measurements performed by the same team, and 89 of which had measurements performed by both teams. Intra-anthropometrist TEM (and relative TEM) were 0.35 cm (0.35%) for height, 0.05 kg (0.39%) for weight, and 0.18 cm (1.27%) for MUAC. Corresponding values for inter-anthropometrist reliability were 0.67 cm (0.75%) for height, 0.09 kg (0.79%) for weight, and 0.22 kg (1.53%) for MUAC. Inter-anthropometrist measurement error was greater for smaller children than for larger children.Measurements of height and weight were more reproducible than measurements of MUAC and measurements of larger children were more reliable than those for smaller children. Community-drawn anthropometrists can provide reliable measurements that could be used to assess the impact of interventions for childhood undernutrition

Gender identity change in a female adolescent transsexual

Two years of individual and milieu therapy are described of a 141/2-year-old girl who had presented with the persistent request to have a sex-change operation since age 12. Her past history was obtained from her parents and the records of the child guidance clinic which evaluated her at 3 years of age. She gives a history of remarkable tomboyism during her latency years and increasing withdrawal from peers and family during early adolescence. The patient's personal and family dynamics are explored, and these major therapeutic themes are discussed. The individual and milieu therapy are described and discussed with some speculation about the reasons for her positive response to psychotherapy. It would appear that this is a rare case of a postpubertal female transsexual reported to have made a gender identity change.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44103/1/10508_2005_Article_BF01541204.pd

Evaluated displacement and gas production cross-sections for materials irradiated with intermediate energy nucleons

International Conference on Nuclear Data for Science and Technology (ND) -- SEP 11-16, 2016 -- Bruges, BELGIUMWOS: 000426429500034Atomic displacement and gas production cross-sections were obtained for a number of materials to calculate radiation damage and gas production rate in nuclear-and fusion reactors, and neutron spallation sources. An advanced atomistic modelling approach was applied for calculations of the number of stable displacements in materials.Fusion for Energy [F4E-GRT-168.01, F4E-GRT-168.02]The work leading to this publication has been funded partially by Fusion for Energy under the Specific Grant Agreements F4E-GRT-168.01 and F4E-GRT-168.02. This publication reflects the views only of the authors, and Fusion for Energy cannot be held responsible for any use which may be made of the information contained therein

A rebellious past : history, theatre and the England riots

Alain Badiou has argued that the England riots of 2011, in dialogue with societal upheavals around the world that same year, demonstrated fundamental crises in our governing social, economic and political discourses. Whilst institutional responses to the riots treated them as an aberration, Badiou believes them to be symptomatic of a broader rebirth of ‘history’ – the coalescing of past and present events into a congruent trajectory with powerful implications for the future. Using Badiou’s argument as a starting point, this article considers two theatrical responses to the riots – Nicholas Kent’s premiere of Gillian Slovo’s The Riots at the Tricycle, and Sean Holmes’ revival of Edward Bond’s Saved at the Lyric Hammersmith. By looking at the ways in which the productions sought to historicise the riots, I unpick both their interpretations of these events, and the contributions they were able to make to the urgent and ongoing discussions that the riots have generated.PostprintPeer reviewe

The Effect of Locally Delivered Controlledâ Release Doxycycline or Scaling and Root Planing on Periodontal Maintenance Patients Over 9 Months

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/142157/1/jper0022.pd

Use of mixed methods designs in substance research: a methodological necessity in Nigeria

The utility of mixed methods (qualitative and quantitative) is becoming increasingly accepted in health sciences, but substance studies are yet to substantially benefit from such utilities. While there is a growing number of mixed methods alcohol articles concerning developed countries, developing nations are yet to embrace this method. In the Nigerian context, the importance of mixed methods research is yet to be acknowledged. This article therefore, draws on alcohol studies to argue that mixed methods designs will better equip scholars to understand, explore, describe and explain why alcohol consumption and its related problems are increasing in Nigeria. It argues that as motives for consuming alcohol in contemporary Nigeria are multiple, complex and evolving, mixed method approaches that provide multiple pathways for proffering solutions to problems should be embraced