| 1. |
- Schweinsberg, Martin, et al.
(författare)
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Same data, different conclusions : Radical dispersion in empirical results when independent analysts operationalize and test the same hypothesis
- 2021
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Ingår i: Organizational Behavior and Human Decision Processes. - : Elsevier BV. - 0749-5978 .- 1095-9920. ; 165, s. 228-249
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Tidskriftsartikel (refereegranskat)abstract
- In this crowdsourced initiative, independent analysts used the same dataset to test two hypotheses regarding the effects of scientists' gender and professional status on verbosity during group meetings. Not only the analytic approach but also the operationalizations of key variables were left unconstrained and up to individual analysts. For instance, analysts could choose to operationalize status as job title, institutional ranking, citation counts, or some combination. To maximize transparency regarding the process by which analytic choices are made, the analysts used a platform we developed called DataExplained to justify both preferred and rejected analytic paths in real time. Analyses lacking sufficient detail, reproducible code, or with statistical errors were excluded, resulting in 29 analyses in the final sample. Researchers reported radically different analyses and dispersed empirical outcomes, in a number of cases obtaining significant effects in opposite directions for the same research question. A Boba multiverse analysis demonstrates that decisions about how to operationalize variables explain variability in outcomes above and beyond statistical choices (e.g., covariates). Subjective researcher decisions play a critical role in driving the reported empirical results, underscoring the need for open data, systematic robustness checks, and transparency regarding both analytic paths taken and not taken. Implications for orga-nizations and leaders, whose decision making relies in part on scientific findings, consulting reports, and internal analyses by data scientists, are discussed.
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| 2. |
- Brodin, N., et al.
(författare)
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Coaching patients with early rheumatoid arthritis to healthy physical activity : A multicenter, randomized, controlled study
- 2008
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Ingår i: Arthritis and Rheumatism. - Hoboken, NJ : Wiley. - 0004-3591 .- 1529-0131. ; 59:3, s. 325-331
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Tidskriftsartikel (refereegranskat)abstract
- Objective. To investigate the effect of a 1-year coaching program for healthy physical activity on perceived health status, body function, and activity limitation in patients with early rheumatoid arthritis. Methods. A total of 228 patients (169 women, 59 men, mean age 55 years, mean time since diagnosis 21 months) were randomized to 2 groups after assessments with the EuroQol visual analog scale (VAS), Grippit, Timed-Stands Test, Escola Paulista de Medicina Range of Motion scale, walking in a figure-of-8, a visual analog scale for pain, the Health Assessment Questionnaire disability index, a self-reported physical activity questionnaire, and the Disease Activity Score in 28 joints. All patients were regularly seen by rheumatologists and underwent rehabilitation as prescribed. Those in the intervention group were further individually coached by a physical therapist to reach or maintain healthy physical activity (=30 minutes, moderately intensive activity, most days of the week). Results. The retention rates after 1 year were 82% in the intervention group and 85% in the control group. The percentages of individuals in the intervention and control groups fulfilling the requirements for healthy physical activity were similar before (47% versus 51%, P > 0.05) and after (54% versus 44%, P > 0.05) the intervention. Analyses of outcome variables indicated improvements in the intervention group over the control group in the EuroQol VAS (P = 0.025) and muscle strength (Timed-Stands Test, P = 0.000) (Grippit, P = 0.003), but not in any other variables assessed. Conclusion. A 1-year coaching program for healthy physical activity resulted in improved perceived health status and muscle strength, but the mechanisms remain unclear, as self-reported physical activity at healthy level did not change. © 2008, American College of Rheumatology.
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| 3. |
- Birch, Jens, et al.
(författare)
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In-beam test of the Boron-10 Multi-Grid neutron detector at the IN6 time-of-flight spectrometer at the ILL
- 2014
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Ingår i: INTERNATIONAL WORKSHOP ON NEUTRON OPTICS AND DETECTORS (NOPandD 2013). - : IOP Publishing: Conference Series / Institute of Physics (IoP).
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Konferensbidrag (refereegranskat)abstract
- A neutron detector concept based on solid layers of boron carbide enriched in 1 B has been in development for the last few years as an alternative for He-3 by collaboration between the ILL, ESS and Linkoping University. This Multi-Grid detector uses layers of aluminum substrates coated with (B4C)-B-10 on both sides that are traversed by the incoming neutrons. Detection is achieved using a gas counter readout principle. By segmenting the substrate and using multiple anode wires, the detector is made inherently position sensitive. This development is aimed primarily at neutron scattering instruments with large detector areas, such as time-of-flight chopper spectrometers. The most recent prototype has been built to be interchangeable with the He-3 detectors of IN6 at ILL. The 1 B detector has an active area of 32 x 48 cm(2). It was installed at the IN6 instrument and operated for several weeks, collecting data in parallel with the regularly scheduled experiments, thus providing the first side-by-side comparison with the conventional He-3 detectors. Results include an efficiency comparison, assessment of the in-detector scattering contribution, sensitivity to gamma-rays and the signal-to-noise ratio in time-of-flight spectra. The good expected performance has been confirmed with the exception of an unexpected background count rate. This has been identified as natural alpha activity in aluminum. New convertor substrates are under study to eliminate this source of background.
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| 4. |
- Muraro, A., et al.
(författare)
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Neutron radiography as a non-destructive method for diagnosing neutron converters for advanced thermal neutron detectors
- 2016
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Ingår i: Journal of Instrumentation. - : Institute of Physics (IOP). - 1748-0221. ; 11:C03033
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Tidskriftsartikel (refereegranskat)abstract
- Due to the well-known problem of He-3 shortage, a series of different thermal neutron detectors alternative to helium tubes are being developed, with the goal to find valid candidates for detection systems for the future spallation neutron sources such as the European Spallation Source (ESS). A possible He-3-free detector candidate is a charged particle detector equipped with a three dimensional neutron converter cathode (3D-C). The 3D-C currently under development is composed by a series of alumina (Al2O3) lamellas coated by 1 mu m of B-10 enriched boron carbide (B4C). In order to obtain a good characterization in terms of detector efficiency and uniformity it is crucial to know the thickness, the uniformity and the atomic composition of the B4C neutron converter coating. In this work a non-destructive technique for the characterization of the lamellas that will compose the 3D-C was performed using neutron radiography. The results of these measurements show that the lamellas that will be used have coating uniformity suitable for detector applications. This technique (compared with SEM, EDX, ERDA, XPS) has the advantage of being global (i.e. non point-like) and non-destructive, thus it is suitable as a check method for mass production of the 3D-C elements.
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| 5. |
- Landälv, Ludvig, 1982-, et al.
(författare)
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Phase composition and transformations in magnetron-sputtered (Al,V)2O3 coatings
- 2019
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Ingår i: Thin Solid Films. - : Elsevier BV. - 0040-6090 .- 1879-2731. ; 688
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Tidskriftsartikel (refereegranskat)abstract
- Coatings of (Al1-xVx)2O3, with x ranging from 0 to 1, were deposited by pulsed DC reactive sputter deposition on Si(100) at a temperature of 550 °C. XRD showed three different crystal structures depending on V-metal fraction in the coating: α-V2O3 rhombohedral structure for 100 at.% V, a defect spinel structure for the intermediate region, 63–42 at.% V. At lower V-content, 18 and 7 at.%, a gamma-alumina-like solid solution was observed, shifted to larger d-spacing compared to pure γ-Al2O3. The microstructure changes from large columnar faceted grains for α-V2O3 to smaller equiaxed grains when lowering the vanadium content towards pure γ-Al2O3. Annealing in air resulted in formation of V2O5 crystals on the surface of the coating after annealing to 500 °C for 42 at.% V and 700 °C for 18 at.% V metal fraction respectively. The highest thermal stability was shown for pure γ-Al2O3-coating, which transformed to α-Al2O3 after annealing to 1100 °C. Highest hardness was observed for the Al-rich oxides, ~24 GPa. The latter decreased with increasing V-content, larger than 7 at.% V metal fraction. The measured hardness after annealing in air decreased in conjunction with the onset of further oxidation of the coatings.
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| 6. |
- Lewin, Erik, et al.
(författare)
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On the origin of a third spectral component of C1s XPS-spectra for nc-TiC/a-C nanocomposite thin films
- 2008
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Ingår i: Surface & Coatings Technology. - : Elsevier BV. - 0257-8972 .- 1879-3347. ; 202:15, s. 3563-3570
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Tidskriftsartikel (refereegranskat)abstract
- X-ray photoelectron spectroscopy (XPS) spectra of sputter-etched nc-TiC/a-C nanocomposite thin films published in literature show an extra feature of unknown origin in the C1s region. This feature is situated between the contributions of carbide and the carbon matrix. We have used high kinetic energy XPS (HIKE-XPS) on magnetron-sputtered nc-TiC/a-C thin films to show that this feature represents a third chemical environment in the nanocomposites, besides the carbide and the amorphous carbon. Our results show that component is present in as-deposited samples, and that the intensity is strongly enhanced by Ar+-ion etching. This third chemical environment may be due to interface or disorder effects. The implications of these observations on the XPS analysis of nanocomposites are discussed in the light of overlap problems for ternary carbon based systems.
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| 7. |
- Mei, A B, et al.
(författare)
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Physical properties of epitaxial ZrN/MgO(001) layers grown by reactive magnetron sputtering
- 2013
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Ingår i: Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films. - : American Vacuum Society. - 0734-2101 .- 1520-8559. ; 31:6, s. 061516-
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Tidskriftsartikel (refereegranskat)abstract
- Single-crystal ZrN films, 830 nm thick, are grown on MgO(001) at 450 degrees C by magnetically unbalanced reactive magnetron sputtering. The combination of high-resolution x-ray diffraction reciprocal lattice maps, high-resolution cross-sectional transmission electron microscopy, and selected-area electron diffraction shows that ZrN grows epitaxially on MgO(001) with a cube-on-cube orientational relationship, (001)(ZrN)parallel to(001)(MgO) and [100](ZrN)parallel to[100](MgO). The layers are essentially fully relaxed with a lattice parameter of 0.4575 nm, in good agreement with reported results for bulk ZrN crystals. X-ray reflectivity results reveal that the films are completely dense with smooth surfaces (roughness = 1.3 nm, consistent with atomic-force microscopy analyses). Based on temperature-dependent electronic transport measurements, epitaxial ZrN/MgO(001) layers have a room-temperature resistivity rho(300K) of 12.0 mu Omega-cm, a temperature coefficient of resistivity between 100 and 300K of 5.6 x 10(-8) Omega-cm K-1, a residual resistivity rho(o) below 30K of 0.78 mu Omega-cm (corresponding to a residual resistivity ratio rho(300K)/rho(15K) = 15), and the layers exhibit a superconducting transition temperature of 10.4 K. The relatively high residual resistivity ratio, combined with long in-plane and out-of-plane x-ray coherence lengths, xi(parallel to) = 18 nm and xi(perpendicular to) = 161 nm, indicates high crystalline quality with low mosaicity. The reflectance of ZrN(001), as determined by variable-angle spectroscopic ellipsometry, decreases slowly from 95% at 1 eV to 90% at 2 eV with a reflectance edge at 3.04 eV. Interband transitions dominate the dielectric response above 2 eV. The ZrN(001) nanoindentation hardness and modulus are 22.7 +/- 1.7 and 450 +/- 25 GPa.
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| 8. |
- Mei, A. B., et al.
(författare)
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Reflection thermal diffuse x-ray scattering for quantitative determination of phonon dispersion relations
- 2015
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Ingår i: Physical Review B. Condensed Matter and Materials Physics. - : AMER PHYSICAL SOC. - 1098-0121 .- 1550-235X. ; 92:17, s. 174301-
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Tidskriftsartikel (refereegranskat)abstract
- Synchrotron reflection x-ray thermal diffuse scattering (TDS) measurements, rather than previously reported transmission TDS, are carried out at room temperature and analyzed using a formalism based upon second-order interatomic force constants and long-range Coulomb interactions to obtain quantitative determinations of MgO phonon dispersion relations (h) over bar omega(j) (q), phonon densities of states g((h) over bar omega), and isochoric temperature-dependent vibrational heat capacities c(v) (T). We use MgO as a model system for investigating reflection TDS due to its harmonic behavior as well as its mechanical and dynamic stability. Resulting phonon dispersion relations and densities of states are found to be in good agreement with independent reports from inelastic neutron and x-ray scattering experiments. Temperature-dependent isochoric heat capacities cv (T), computed within the harmonic approximation from (h) over bar omega(j) (q) values, increase with temperature from 0.4 x 10(-4) eV/atom K at 100 K to 1.4 x 10(-4) eV/atom K at 200 K and 1.9 x 10(-4) eV/atom K at 300 K, in excellent agreement with isobaric heat capacity values c(p) (T) between 4 and 300 K. We anticipate that the experimental approach developed here will be valuable for determining vibrational properties of heteroepitaxial thin films since the use of grazing-incidence (theta less than or similar to theta(c), where theta(c) is the density-dependent critical angle) allows selective tuning of x-ray penetration depths to less than or similar to 10 nm.
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| 9. |
- Neidhardt, J., et al.
(författare)
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Transmission electron microscopy studies and simulation of the indentation response of superelastic fullerenelike carbon nitride thin films
- 2008
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Ingår i: Journal of Applied Physics. - : AIP Publishing. - 0021-8979 .- 1089-7550. ; 103:12
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Tidskriftsartikel (refereegranskat)abstract
- The highly elastic behavior of fullerenelike carbon nitride thin films on single crystal Si (001) substrates has been studied by nanoindentation. The films exhibit a microstructure of frequently bent and intersecting graphene sheets. Transmission electron microscopy of indented areas revealed no tendency to plastic deformation in the highly elastic and compliant film. Also, a unique deformation pattern in the Si substrate is observed, where a {111} facetted inverted pyramid of untransformed Si remained intact under the indenter with a retained CNx /Si (001) interface. Analytical approaches using the effective indenter method, supported by finite element methods, are employed to understand the nonlinear but fully elastic behavior of the coatings as well as to describe the critical parameters for the deformation and phase transformation of the Si substrate. © 2008 American Institute of Physics.
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| 10. |
- Pollard, Michael K, et al.
(författare)
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Definition of IFN-gamma-related pathways critical for chemically-induced systemic autoimmunity
- 2012
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Ingår i: Journal of Autoimmunity. - : Elsevier. - 0896-8411 .- 1095-9157. ; 39:4, s. 323-331
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Tidskriftsartikel (refereegranskat)abstract
- IFN-gamma is essential for idiopathic and murine mercury-induced systemic autoimmunity (mHgIA), and heterozygous IFN-gamma(+/-) mice also exhibit reduced disease. This suggests that blocking specific IFN-gamma-related pathways that may only partially inhibit IFN-gamma production or function will also suppress autoimmunity. To test this hypothesis, mice deficient in genes regulating IFN-gamma expression (Casp1, Nlrp3, Il12a, Il12b, Stat4) or function (Ifngr1, Irf1) were examined for mHgIA susceptibility. Absence of either Ifngr1 or Irf1 resulted in a striking reduction of disease, while deficiency of genes promoting IFN-gamma expression had modest to no effect. Furthermore, both Irf1- and Ifng-deficiency only modestly reduced the expansion of CD44(hi) and CD44(hi)CD55(lo) CD4(+) T cells, indicating that they are not absolutely required for T cell activation. Thus, there is substantial redundancy in genes that regulate IFN-gamma expression in contrast to those that mediate later signaling events. These findings have implications for the therapeutic targeting of IFN-gamma pathways in systemic autoimmunity.
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