| 61. |
- Gorbatov, O. I., et al.
(author)
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Vacancy-solute interactions in ferromagnetic and paramagnetic bcc iron : Ab initio calculations
- 2011
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In: Journal of Nuclear Materials. - : Elsevier BV. - 0022-3115 .- 1873-4820. ; 419:1-3, s. 248-255
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Journal article (peer-reviewed)abstract
- Vacancy-solute interactions play a crucial role in diffusion-controlled processes, such as ordering or decomposition, which occur in alloys under heat treatment or under irradiation. Detailed knowledge of these interactions is important for predicting long-term behavior of nuclear materials (such as reactor steels and nuclear-waste containers) as well as for advancing our general understanding of kinetic processes in alloys. Using first-principles calculations based on the density functional theory and employing the locally self-consistent Green's function technique, we develop a database of vacancy-solute interactions in dilute alloys of bcc Fe with 3p (Al, Si, P, S), 3d (Sc-Cu), and 4d (Y-Ag) elements. Unrelaxed interactions within the first three coordination shells have been computed in the ferromagnetic state as well as in the paramagnetic (disordered local moment) state of the iron matrix. Magnetism is found to have a strong effect on the vacancy-solute interactions. Implications of the obtained results for interpreting the effects of vacancy trapping and enhanced impurity diffusion are discussed.
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| 62. |
- Hallqvist, Andreas, 1973, et al.
(author)
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Concurrent cetuximab and radiotherapy after docetaxel-cisplatin induction chemotherapy in stage III NSCLC : Satellite-A phase II study from the Swedish Lung Cancer Study Group
- 2011
-
In: Lung Cancer. - : Elsevier BV. - 0169-5002 .- 1872-8332. ; 71:2, s. 166-172
-
Journal article (peer-reviewed)abstract
- Background: Several attempts to increase the locoregional control in locally advanced lung cancer including concurrent chemotherapy, accelerated fractionation and dose escalation have been made during the last years. As the EGFR directed antibody cetuximab has shown activity concurrent with radiotherapy in squamous cell carcinoma of the head and neck, as well as in stage IV NSCLC combined with chemotherapy, we wanted to investigate radiotherapy with concurrent cetuximab in locally advanced NSCLC, a tumour type often over expressing the EGF-receptor. Methods: Between February 2006 and August 2007 75 patients in stage Ill NSCLC with good performance status (PS 0 or 1) and adequate lung function (FEV1 > 1.0) were enrolled in this phase II study at eight institutions. Treatment consisted of 2 cycles of induction chemotherapy, docetaxel 75 mg/m(2) and cisplatin 75 mg/m(2) with 3 weeks interval. An initial dose of cetuximab 400 mg/m(2) was given before start of 3D-CRT to 68 Gy with 2 Gy per fraction in 7 weeks concurrent with weekly cetuximab 250 mg/m(2). Toxicity was scored weekly during radiotherapy (CTC 3.0), and after treatment the patients were followed every third month with CT-scans, toxicity scoring and QLQ. Results: Seventy-one patients were eligible for analysis as four were incorrectly enrolled. Histology: adenocarcinoma 49%, squamous cell carcinoma 39% and other NSCLC 12%. The majority had PS 0 (62.5%), median age 62.2 (42-81), 50% were women and 37% had a pre-treatment weight loss > 5%. Toxicity: esophagitis grade 1-2: 72%; grade 3:1.4%. Hypersensitivity reactions grade 3-4: 5.6%. Febrile neutropenia grade 3-4: 15.4%. Skin reactions grade 1-2: 74%; grade 3: 4.2%. Diarrhoea grade 1-2: 38%; grade 3: 11.3%. Pneumonitis grade 1-2: 26.8%; grade 3: 4.2%; grade 5:1.4%. The median follow-up was 39 months for patients alive and the median survival was 17 months with a 1-, 2- and 3-year OS of 66%, 37% and 29% respectively. Until now local or regional failure has occurred in 20 patients and 22 patients have developed distant metastases. Weight loss, PS and stage were predictive for survival in univariate as well as in multivariate analysis. Conclusion: Induction chemotherapy followed by concurrent cetuximab and RT to 68 Gy is clearly feasible with promising survival. Toxicity, e.g. pneumonitis and esophagitis is low compared to most schedules with concurrent chemotherapy. This treatment strategy should be evaluated in a randomised manner vs. concurrent chemoradiotherapy to find out if it is a valid treatment option.
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| 63. |
- Heathman, S., et al.
(author)
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Structural investigation of californium under pressure
- 2013
-
In: Physical Review B. Condensed Matter and Materials Physics. - : American Physical Society. - 1098-0121 .- 1550-235X. ; 87:21, s. 214111-
-
Journal article (peer-reviewed)abstract
- The high-pressure structural behavior of californium has been studied experimentally and theoretically up to 100 GPa. A valence change from divalent to trivalent forms was observed under modest pressure revealing californium to be the only actinide to exhibit more than one metallic valence at near to ambient conditions as is the case for cerium in the lanthanide series. Three metallic valencies and four different crystallographic phases were observed in californium as a function of pressure. High-pressure techniques, synchrotron radiation, and ab initio electronic structure calculations of total energies were used to investigate the material and to determine the role which californium's 5f electrons play in influencing these transitions. The crystallographic structures observed are similar to those found in the preceding actinide elements, curium and americium, with the initially localized 5f states becoming completely delocalized under the influence of high pressure.
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| 64. |
- Holmberg, Ingvar, et al.
(author)
-
A simultaneous model of long-term regional job and population changes
- 2019
-
In: The Economics of Disappearing Distance. Börje Johansson (red.). - : Taylor and Francis. - 9781315194479 ; , s. 161-189, s. 161-189
-
Book chapter (other academic/artistic)abstract
- This chapter examines a model structure that can project multiregional job and populations dynamics. Such dynamics include the attraction of firms and households to each functional region. The method to identify a region’s internal market potential is in a fundamental way related to the delineation of the geographic extension of a functional region. A functional region is distinguished by its concentration of activities and of its infrastructure which facilitates particularly high factor mobility within its interaction borders. The resource-based theory has been challenged in recent decades by scale-based models, which explain location and trade patterns in a context of internal and external economies of scale. The chapter presents model for long term projection of employment and population growth in Swedish municipalities. In Sweden a functional region normally consists of several interacting municipalities. Such a group of municipalities is considered to be integrated into a region when the interaction between the municipalities is intensive.
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| 65. |
- Hu, Q. -M, et al.
(author)
-
Composition dependent hardness of covalent solid solutions and its electronic structure origin
- 2016
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In: Ceramic Engineering and Science Proceedings. - : American Ceramic Society. - 9781119040439 ; , s. 143-151
-
Conference paper (peer-reviewed)abstract
- Materials with high hardness are technologically important for cutting and forming tools, engine components, valves, seals, gears, many types of wear resistant coatings, etc. The search for harder materials has a long history and remains one of the most active areas in materials science. Predictive tools for hardness will make this effort more efficient. In the past ten years, several hardness models based on electronic structure theory for perfect elemental materials/binary covalent and ionic compounds have been put forward. However, most of the engineering materials are alloys (solid solutions) and inevitably contain some impurities or defects such as vacancies. Theoretical predictions of the hardness of this kind of materials have rarely been touched. We have presented a hardness formula for multi-component covalent solid solutions. Here the composition dependence of the hardness of some covalent/ionic solid solutions, predicted with this formula, taking the parameters from our first-principles calculations, will be reported in comparison with experimental results. Furthermore, the electronic structure origin of the composition dependence of the hardness will be discussed. We will show that the band-filling effect proposed in literature to account for the composition dependence of the hardness of e.g. TiCxN1-x fails for some of the systems. Instead, we suggest that the composition dependence is controlled by the competition between the band-filling effect and the strength of electronic states hybridization.
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| 66. |
- Hu, Qing-Miao, et al.
(author)
-
Magnetoelastic effects in Ni2Mn1+xGa1-x alloys from first-principles calculations
- 2010
-
In: Physical Review B. Condensed Matter and Materials Physics. - 1098-0121 .- 1550-235X. ; 81:6, s. 064108-1-064108-5
-
Journal article (peer-reviewed)abstract
- The magnetic coupling between Mn atoms on Ga sublattice (Mn-Ga) and Mn atoms on Mn sublattice (Mn-Mn) in Ni2Mn1+xGa1-x alloy and its effect on the elastic modulus of the alloy are investigated by the use of first-principles methods. It is shown that, for x = 0.25, the state with antiparallel Mn-Ga-Mn-Mn magnetic coupling is slightly more stable than that with parallel coupling, whereas for x = 0.10, both magnetic states are almost degenerated. For both antiparallel and parallel Mn-Ga-Mn-Mn magnetic couplings, the bulk modulus (B) of Ni2Mn1+xGa1-x deviates from the general e/a-B relationship with e/a being the number of valence electrons per atom. The shear modulus C' versus the martensitic transformation temperature T-M for Ni2Mn1+xGa1-x with antiparallel Mn-Ga-Mn-Mn magnetic coupling is in line with the general C'-T-M relationship for Ni2MnGa-based alloys, in contrast to the case of parallel Mn-Ga-Mn-Mn magnetic coupling.
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| 67. |
- Huang, L., et al.
(author)
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Anomalous temperature dependence of elastic constant c(44) in V, Nb, Ta, Pd, and Pt
- 2010
-
In: Journal of Physics and Chemistry of Solids. - : Elsevier BV. - 0022-3697 .- 1879-2553. ; 71:8, s. 1065-1068
-
Journal article (peer-reviewed)abstract
- The anomalous temperature dependence of elastic constant c(44) for elements V. Nb, Ta, Pd, and Pt, has been calculated using first-principles theory. It is shown that the variation of elastic constant for simple elements can be approximated as the sum of thermal expansion and electronic components. The thermal expansion contributes the normal linearly decreasing effect to the elastic constant with temperature, while electronic contribution is determined by the unique character of electronic structure of elements and leads to the anomalous effect to the elastic constant with temperature.
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| 68. |
- Hussain, Tanveer, et al.
(author)
-
BC3 Sheet Functionalized with Lithium-Rich Species Emerging as a Reversible Hydrogen Storage Material
- 2015
-
In: ChemPhysChem. - : Wiley. - 1439-4235 .- 1439-7641. ; 16:3, s. 634-639
-
Journal article (peer-reviewed)abstract
- The decoration of a BC3 monolayer with the polylithiated molecules CLi4 and OLi2 has been extensively investigated to study the hydrogen-storage efficiency of the materials by first principles electronic structure calculations. The binding energies of both lithiated species with the BC3 substrate are much higher than their respective cohesive energies, which confirms the stability of the doped systems. A significant positive charge on the Li atom in each of the dopants facilitates the adsorption of multiple H-2 molecules under the influence of electrostatic and van der Waals interactions. We observe a high H-2-storage capacity of 11.88 and 8.70 wt% for the BC3-CLi4 and BC3-OLi2 systems, respectively, making them promising candidates as efficient energy-storage systems.
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| 69. |
- Hussain, Tanveer, et al.
(author)
-
Enhancement of energy storage capacity of Mg functionalized silicene and silicane under external strain
- 2014
-
In: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 105:12, s. 123903-
-
Journal article (peer-reviewed)abstract
- The electronic structure, stability, and hydrogen storage capacity of strain induced Mg functionalized silicene (SiMg) and silicane (SiHMg) monolayers have been studied by means of van der Waals induced first principles calculations. A drastic increase in the binding energy of Mg adatoms on both the monolayers under the biaxial symmetric strain of 10% ensures the uniform distribution of dopants over the substrates. A significant positive charge on each Mg accumulates a maximum of six H-2 molecules with H-2 storage capacity of 8.10% and 7.95% in case of SiMg and SiHMg, respectively. The average adsorption energy for H-2 molecules has been found ideal for practical H-2 storage materials.
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| 70. |
- Hwang, Choongyu, et al.
(author)
-
Ytterbium-driven strong enhancement of electron-phonon coupling in graphene
- 2014
-
In: Physical Review B. Condensed Matter and Materials Physics. - 1098-0121 .- 1550-235X. ; 90:11, s. 115417-
-
Journal article (peer-reviewed)abstract
- We present a high-resolution angle-resolved photoemission spectroscopy study in conjunction with first-principles calculations to investigate how the interaction of electrons with phonons in graphene is modified by the presence of Yb. We find that the charges transferred from Yb to the graphene layer hybridize with the graphene pi bands, leading to a strong enhancement of the electron-phonon interaction. Specifically, the electron-phonon coupling constant is increased by as much as a factor of 10 upon the introduction of Yb with respect to as-grown graphene (<= 0.05). The observed coupling constant constitutes the highest value ever measured for graphene and suggests that the hybridization between graphene and the adatoms might be a critical parameter in realizing superconducting graphene.
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