| 1. |
- Santoro, V., et al.
(författare)
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HighNESS conceptual design report: Volume I
- 2024
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Ingår i: Journal of Neutron Research. - 1023-8166 .- 1477-2655. ; 25:3-4, s. 85-314
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Tidskriftsartikel (refereegranskat)abstract
- The European Spallation Source, currently under construction in Lund, Sweden, is a multidisciplinary international laboratory. Once completed to full specifications, it will operate the world’s most powerful pulsed neutron source. Supported by a 3 million Euro Research and Innovation Action within the EU Horizon 2020 program, a design study (HighNESS) has been completed to develop a second neutron source located below the spallation target. Compared to the first source, designed for high cold and thermal brightness, the new source has been optimized to deliver higher intensity, and a shift to longer wavelengths in the spectral regions of cold (CN, 2–20 Å), very cold (VCN, 10–120 Å), and ultracold (UCN, >500 Å) neutrons. The second source comprises a large liquid deuterium moderator designed to produce CN and support secondary VCN and UCN sources. Various options have been explored in the proposed designs, aiming for world-leading performance in neutronics. These designs will enable the development of several new instrument concepts and facilitate the implementation of a high-sensitivity neutron-antineutron oscillation experiment (NNBAR). This document serves as the Conceptual Design Report for the HighNESS project, representing its final deliverable.
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| 2. |
- Santoro, V., et al.
(författare)
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HighNESS conceptual design report: Volume II. the NNBAR experiment.
- 2024
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Ingår i: Journal of Neutron Research. - 1023-8166 .- 1477-2655. ; 25:3-4, s. 315-406
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Tidskriftsartikel (refereegranskat)abstract
- A key aim of the HighNESS project for the European Spallation Source is to enable cutting-edge particle physics experiments. This volume presents a conceptual design report for the NNBAR experiment. NNBAR would exploit a new cold lower moderator to make the first search in over thirty years for free neutrons converting to anti-neutrons. The observation of such a baryon-number-violating signature would be of fundamental significance and tackle open questions in modern physics, including the origin of the matter-antimatter asymmetry. This report shows the design of the beamline, supermirror focusing system, magnetic and radiation shielding, and anti-neutron detector necessary for the experiment. A range of simulation programs are employed to quantify the performance of the experiment and show how background can be suppressed. For a search with full background suppression, a sensitivity improvement of three orders of magnitude is expected, as compared with the previous search. Civil engineering studies for the NNBAR beamline are also shown, as is a costing model for the experiment.
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| 3. |
- Andersson-Sköld, Yvonne, et al.
(författare)
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Quick clay - A case study of chemical perspective in Southwest Sweden
- 2005
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Ingår i: Engineering Geology. - : Elsevier BV. - 0013-7952. ; 82:2, s. 107-118
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Tidskriftsartikel (refereegranskat)abstract
- Quick clay, a soil that changes from normal firm ground to a liquid mass when it is disturbed, has been involved in most of the large and serious clay slides in Sweden, Norway and Canada. The location, time of occurrence and size of quick clay slides are difficult to predict and large slides may cause great devastation. Some geochemical studies of Swedish quick clay were done in the 1960s and early 1970s, but no systematic studies of the interrelationships of pore water chemistry, mineralogy, geotechnical properties and other parameters on quick clays in Sweden have been published. Such studies are of national and general interest because of the many combinations of rock flour source areas and sedimentation conditions that occurred across central Sweden and into the Baltic Sea area during deglaciation. In this study, geotechnical properties related to the in situ chemistry at one quick clay site were extensively studied, and spot sampling was conducted at two other locations in Southwest Sweden. In this area the clay minerals mainly are non-expanding phyllosilicate minerals (illite) and primary minerals (quartz, feldspar), which is consistent with previous studies of quick clay mineralogy. Extensive leaching has occurred at all three locations. At the extensively studied site, Surte, the lowest salinity was found at the greatest depth, inferring that the leaching by fresh water was accomplished by water movement upward and laterally through the sediment from the underlying bedrock. This is consistent with the local setting where bedrock hills rise sharply to over 100 in above the marine sediment surface. An artesian pressure would also be anticipated at this location. There is a correlation (negative) between sensitivity and salinity but there is an indication that the maximum salinity or electrical conductivity consistent with the quick clay behaviour is higher than reported elsewhere. However, for high sensitivities the salinity is about the same as reported elsewhere. In the deepest part of the borehole, there is a higher content of Fe and Al in the pore water, indicating reduced state. Further work is needed to confirm the difference in salinity and to investigate the possible interplay of salinity and potential dispersing agents such as the role of anoxic conditions, in this region. Further work is especially needed in the locations where the sediment accumulation occurred under lower salinity conditions. At all three locations, high remoulded shear strength and low sensitivity have been seen near the surface together with a decrease in pore water cation concentrations. (c) 2005 Elsevier B.V. All rights reserved.
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| 4. |
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| 5. |
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| 6. |
- Johansson, H, et al.
(författare)
-
UTILITY LOSS AFTER A SENTINEL FRACTURE
- 2018
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Ingår i: OSTEOPOROSIS INTERNATIONAL. - 0937-941X. ; 29, s. S72-S73
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)
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| 7. |
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| 8. |
- Kayan, K, et al.
(författare)
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Can fall risk be incorporated into fracture risk assessment algorithms: a pilot study of responsiveness to clodronate
- 2009
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Ingår i: Osteoporosis International. - : Springer Science and Business Media LLC. - 0937-941X .- 1433-2965.
-
Tidskriftsartikel (refereegranskat)abstract
- Fall risk does not significantly impact on the efficacy of the bisphosphonate clodronate in reducing the incidence of fracture. INTRODUCTION: The debate about the efficacy of skeletal therapies on fracture risk in women at increased risk of falling continues. We determined whether fall risk impeded the efficacy of clodronate to reduce osteoporotic fracture incidence. METHODS: This is a post hoc analysis of a 3-year placebo-controlled study of bisphosphonate clodronate involving 5,212 women aged 75 years or more. At entry, self-reported multiple falls in the previous month and ability to rise from a chair were documented. Their interaction with treatment efficacy was examined using Poisson regression. RESULTS: Oral doses of clodronate at 800 mg daily reduced osteoporotic fracture incidence by 24% (hazard ration (HR) 0.76, 95% confidence interval 0.63-0.93). The efficacy was similar in women with recent multiple falls compared to those without (HR 0.61 vs. 0.77, p value for interaction >0.30) or impaired ability in rising compared to those with no impairment (HR 0.79 vs. 0.74, respectively; p value > 0.30). CONCLUSION: Fall risk does not significantly impact on the anti-fracture efficacy of clodronate. If confirmed with other agents, fall risk may be incorporated into risk assessment tools designed to target skeletal therapies.
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| 9. |
- McCloskey, E V, et al.
(författare)
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Ten-year fracture probability identifies women who will benefit from clodronate therapy--additional results from a double-blind, placebo-controlled randomised study
- 2009
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Ingår i: Osteoporosis International. - : Springer Science and Business Media LLC. - 0937-941X .- 1433-2965. ; 20:5, s. 811-7
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Tidskriftsartikel (refereegranskat)abstract
- Fracture risk prediction can be enhanced by the concurrent assessment of other clinical risk factors. This study demonstrates that the estimation of an individual's 10-year probability of fracture by the FRAX algorithm identifies patients at high risk of fracture who will respond to bisphosphonate therapy. INTRODUCTION: Treatments for osteoporosis are targeted largely to patients with low bone density (BMD) or a prior fragility fracture. Fracture risk prediction can be enhanced by the concurrent assessment of other clinical risk factors, but it is important to determine whether the risk so identified can be reduced by intervention. We determined the effect of a bisphosphonate on fracture rates when risk was calculated using a new risk algorithm (FRAX). METHODS: Women aged 75 years or more were recruited to a randomised, double-blind controlled trial of 800 mg oral clodronate (Bonefos) daily over 3 years. Baseline clinical risk factors were entered in the FRAX model to compute the 10-year probability of major osteoporotic fractures with or without input of femoral neck BMD. The interaction between fracture probability and treatment efficacy was examined by Poisson regression. RESULTS: In 3,974 women, the interaction between fracture probability and treatment efficacy was significant when probability was assessed without BMD (p = 0.043), but not when BMD was included (p = 0.10). Efficacy was more evident in those deemed at highest risk. For example women lying at the 75th percentile of fracture probability in the absence of BMD (10-year probability 24%) treatment reduced fracture risk by 27% (HR 0.73, 95%CI 0.58-0.92). In those with a fracture probability of 30% (90th percentile), the fracture risk reduction was 38% (HR 0.62, 0.46-0.84). CONCLUSIONS: The estimation of an individual's 10-year probability of fracture by the FRAX algorithm identifies patients at high risk of fracture who will respond to bisphosphonate therapy.
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| 10. |
- Ringsberg, K.C., et al.
(författare)
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Differences in trigger factors and symptoms between patients with asthma-like symptoms and patients with asthma : Development of a basis for a questionnaire
- 2002
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Ingår i: Respiratory Medicine. - : Elsevier BV. - 0954-6111 .- 1532-3064. ; 96:5, s. 305-311
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Tidskriftsartikel (refereegranskat)abstract
- Patients with asthma-like symptoms but with negative asthma tests are often misdiagnosed as having asthma and treated as asthmatics. They describe their trigger factors and symptoms very similar to those of patients with asthma. The aim of the study was to analyze differences in symptoms and trigger factors between asthma-like patients and asthmatics in order to elaborate a basis for a questionnaire for epidemiological and clinical use. A questionnaire with 54 questions about trigger factors and 137 questions about symptoms was sent to 40 patients with asthma-like symptoms and 40 with asthma, all consecutively selected from patients referred to an out-patient clinic for asthma and allergy for investigation of suspected asthma. Data were analyzed statistically in two steps using multiple logistic regression analysis. Significant differences were seen in several trigger factors and symptoms after the first analysis. After the second analysis, seven out of the 54 trigger factors and 22 out of the 137 symptoms emerged as those that most significantly discriminated between the two patient groups. These trigger factors and symptoms can be the basis of a new questionnaire with high discriminating power. Before using it, it is important to evaluate the best combination of variables, add some demographic variables and to test the reliability and validity of this new questionnaire. © 2002 Elsevier Science Ltd.
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| 11. |
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| 12. |
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| 13. |
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| 14. |
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| 15. |
- Harvey, Nicholas C., et al.
(författare)
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Falls Predict Fractures Independently of FRAX Probability : A Meta-Analysis of the Osteoporotic Fractures in Men (MrOS) Study
- 2018
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Ingår i: Journal of Bone and Mineral Research. - : WILEY. - 0884-0431 .- 1523-4681. ; 33:3, s. 510-516
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Tidskriftsartikel (refereegranskat)abstract
- Although prior falls are a well-established predictor of future fracture, there is currently limited evidence regarding the specific value of falls history in fracture risk assessment relative to that of other clinical risk factors and bone mineral density (BMD) measurement. We therefore investigated, across the three Osteoporotic Fractures in Men (MrOS) Study cohorts, whether past falls predicted future fracture independently of FRAX and whether these associations varied with age and follow-up time. Elderly men were recruited from MrOS Sweden, Hong Kong, and USA. Baseline data included falls history (over the preceding 12 months), clinical risk factors, BMD at femoral neck, and calculated FRAX probabilities. An extension of Poisson regression was used to investigate the associations between falls, FRAX probability, and incident fracture, adjusting for age, time since baseline, and cohort in base models; further models were used to investigate interactions with age and follow-up time. Random-effects meta-analysis was used to synthesize the individual country associations. Information on falls and FRAX probability was available for 4365 men in USA (mean age 73.5 years; mean follow-up 10.8 years), 1823 men in Sweden (mean age 75.4 years; mean follow-up 8.7 years), and 1669 men in Hong Kong (mean age 72.4 years; mean follow-up 9.8 years). Rates of past falls were similar at 20%, 16%, and 15%, respectively. Across all cohorts, past falls predicted incident fracture at any site (hazard ratio [HR]=1.69; 95% confidence interval [CI] 1.49, 1.90), major osteoporotic fracture (MOF) (HR=1.56; 95% CI 1.33, 1.83), and hip fracture (HR=1.61; 95% CI 1.27, 2.05). Relationships between past falls and incident fracture remained robust after adjustment for FRAX probability: adjusted HR (95% CI) any fracture: 1.63 (1.45, 1.83); MOF: 1.51 (1.32, 1.73); and hip: 1.54 (1.21, 1.95). In conclusion, past falls predicted incident fracture independently of FRAX probability, confirming the potential value of falls history in fracture risk assessment.
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| 16. |
- Harvey, Nicholas C., et al.
(författare)
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Measures of Physical Performance and Muscle Strength as Predictors of Fracture Risk Independent of FRAX, Falls, and aBMD : A Meta-Analysis Of The Osteoporotic Fractures In Men (MrOS) Study
- 2018
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Ingår i: Journal of Bone and Mineral Research. - : Wiley. - 0884-0431 .- 1523-4681. ; 33:12, s. 2150-2157
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Tidskriftsartikel (refereegranskat)abstract
- Measures of muscle mass, strength, and function predict risk of incident fractures, but it is not known whether this risk information is additive to that from FRAX (fracture risk assessment tool) probability. In the Osteoporotic Fractures in Men (MrOS) Study cohorts (Sweden, Hong Kong, United States), we investigated whether measures of physical performance/appendicular lean mass (ALM) by DXA predicted incident fractures in older men, independently of FRAX probability. Baseline information included falls history, clinical risk factors for falls and fractures, femoral neck aBMD, and calculated FRAX probabilities. An extension of Poisson regression was used to investigate the relationship between time for five chair stands, walking speed over a 6 m distance, grip strength, ALM adjusted for body size (ALM/height(2)), FRAX probability (major osteoporotic fracture [MOF]) with or without femoral neck aBMD, available in a subset of n = 7531), and incident MOF (hip, clinical vertebral, wrist, or proximal humerus). Associations were adjusted for age and time since baseline, and are reported as hazard ratios (HRs) for first incident fracture per SD increment in predictor using meta-analysis. 5660 men in the United States (mean age 73.5 years), 2764 men in Sweden (75.4 years), and 1987 men in Hong Kong (72.4 years) were studied. Mean follow-up time was 8.7 to 10.9 years. Greater time for five chair stands was associated with greater risk of MOF (HR 1.26; 95% CI, 1.19 to 1.34), whereas greater walking speed (HR 0.85; 95% CI, 0.79 to 0.90), grip strength (HR 0.77; 95% CI, 0.72 to 0.82), and ALM/height(2) (HR 0.85; 95% CI, 0.80 to 0.90) were associated with lower risk of incident MOF. Associations remained largely similar after adjustment for FRAX, but associations between ALM/height(2) and MOF were weakened (HR 0.92; 95% CI, 0.85 to 0.99). Inclusion of femoral neck aBMD markedly attenuated the association between ALM/height(2) and MOF (HR 1.02; 95% CI, 0.96 to 1.10). Measures of physical performance predicted incident fractures independently of FRAX probability. Whilst the predictive value of ALM/height(2) was substantially reduced by inclusion of aBMD requires further study, these findings support the consideration of physical performance in fracture risk assessment.
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| 17. |
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| 18. |
- Jensen, J.A.D., et al.
(författare)
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Electrochemically deposited nickel membranes, process-microstructure-property relationships
- 2003
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Ingår i: Surface & Coatings Technology. - 0257-8972 .- 1879-3347. ; 172:1, s. 79-89
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Tidskriftsartikel (refereegranskat)abstract
- This paper reports on the manufacturing, surface morphology, internal structure and mechanical properties of Ni-foils used as membranes in reference-microphones. Two types of foils, referred to as S-type and 0-type foils, were electrochemically deposited from a Watts-type electrolyte, with (S-type) or without (0-type) the use of the sulfur-containing additive sodium saccharin. Both types of Ni-foils appeared perfectly smooth when investigated with scanning electron microscopy (SEM), while atomic force microscopy (AFM) and transmission electron microscopy (TEM) revealed differences in the surface morphologies and a smaller grain-size in the S-type foils. X-Ray diffraction showed a <311> texture component in both types of Ni-foils, most pronounced for 0-type foils. A minor <111> texture component observed in both foil types was strongest in the S-type foils. Mechanically 0-type foils proved more ductile than S-type foils during thin film tensile testing, due to microstructural defects caused by sodium saccharin during deposition. Tensile strengths in the order of 700-1000 MPa were observed - highest for the more ductile 0-type foils. A hardness in the order of 6 GPa (590 HV) was found by nanoindentation. © 2003 Elsevier Science B.V. All rights reserved.
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| 19. |
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| 20. |
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| 21. |
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| 22. |
- Kanis, J A, et al.
(författare)
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The use of clinical risk factors enhances the performance of BMD in the prediction of hip and osteoporotic fractures in men and women.
- 2007
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Ingår i: Osteoporosis international. - : Springer Science and Business Media LLC. - 0937-941X .- 1433-2965. ; 18:8, s. 1033-46
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Tidskriftsartikel (refereegranskat)abstract
- SUMMARY: BMD and clinical risk factors predict hip and other osteoporotic fractures. The combination of clinical risk factors and BMD provide higher specificity and sensitivity than either alone. INTRODUCTION AND HYPOTHESES: To develop a risk assessment tool based on clinical risk factors (CRFs) with and without BMD. METHODS: Nine population-based studies were studied in which BMD and CRFs were documented at baseline. Poisson regression models were developed for hip fracture and other osteoporotic fractures, with and without hip BMD. Fracture risk was expressed as gradient of risk (GR, risk ratio/SD change in risk score). RESULTS: CRFs alone predicted hip fracture with a GR of 2.1/SD at the age of 50 years and decreased with age. The use of BMD alone provided a higher GR (3.7/SD), and was improved further with the combined use of CRFs and BMD (4.2/SD). For other osteoporotic fractures, the GRs were lower than for hip fracture. The GR with CRFs alone was 1.4/SD at the age of 50 years, similar to that provided by BMD (GR = 1.4/SD) and was not markedly increased by the combination (GR = 1.4/SD). The performance characteristics of clinical risk factors with and without BMD were validated in eleven independent population-based cohorts. CONCLUSIONS: The models developed provide the basis for the integrated use of validated clinical risk factors in men and women to aid in fracture risk prediction.
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| 23. |
- Kanis, JA, et al.
(författare)
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Characteristics of recurrent fractures
- 2018
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Ingår i: Osteoporosis international : a journal established as result of cooperation between the European Foundation for Osteoporosis and the National Osteoporosis Foundation of the USA. - : Springer Science and Business Media LLC. - 1433-2965. ; 29:8, s. 1747-1757
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Tidskriftsartikel (refereegranskat)
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| 24. |
- Larsson, K, et al.
(författare)
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Early menopause, low body mass index, and smoking are independent risk factors for developing giant cell arteritis.
- 2006
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Ingår i: Annals of the rheumatic diseases. - : BMJ. - 0003-4967 .- 1468-2060. ; 65:4, s. 529-32
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: To assess female sex hormone related variables in a group of women with biopsy positive giant cell arteritis and a control group. METHODS: 49 women with biopsy positive giant cell arteritis, aged 50 to 69 years at the time of diagnosis, answered a questionnaire on hormonal and reproductive factors. The same questions were answered by a large population of women from the same geographical area in connection with routine mammograms. The results were tested statistically, using logistic regression analysis of each variable adjusted for age, and a multivariate logistic regression analysis including age and the variables which differed significantly between giant cell arteritis and controls. RESULTS: From the multivariate logistic regression analysis, three independent variables were associated with an increased risk of having giant cell arteritis: smoking and being an ex-smoker (odds ratio (OR) = 6.324 (95% confidence interval (CI), 3.503 to 11.418), p<0.0001); body mass index (a reduction of 1.0 kg/m2 increased the risk by 10% (OR = 0.898 (0.846 to 0.952), p = 0.0003); and menopause before the age of 43 (OR = 3.521 (1.717 to 7.220), p = 0.0006). CONCLUSIONS: There was a significant association between hormonal and reproduction related factors and the risk of developing giant cell arteritis in women given the diagnosis before the age of 70. The results suggest a possible role of oestrogen deficiency in the pathogenesis of giant cell arteritis. To confirm the results, an extended study will be needed, including women older than 70.
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| 25. |
- Mangalaraja, R.V., et al.
(författare)
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Combustion synthesis of Y2O3 and Yb-Y2O3 : Part 1: Nanopowders and their characterization
- 2008
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Ingår i: Journal of Materials Processing Technology. - : Elsevier BV. - 0924-0136 .- 1873-4774. ; 208:1-3, s. 415-422
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Tidskriftsartikel (refereegranskat)abstract
- Nanosized yttrium oxide and ytterbium doped yttrium oxide powders were prepared by ceramic combustion techniques such as flash combustion, citrate gel decomposition and glycine combustion using urea, citric acid and glycine respectively as fuels. As synthesized precursors and calcined powders were characterized for their structural, particle size and morphology, and the optimization of calcination process by differential scanning calorimetry and thermal gravimetry. The thermal analyses together with XRD results demonstrate the effectiveness of the combustion process for the synthesis of pure phase nanocrystalline powders. Nanocrystalline pure yttria powders were obtained by the calcination of as-prepared precursors at 1100 °C for 4 h.
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| 26. |
- Mellström, Dan, 1945, et al.
(författare)
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Older men with low serum estradiol and high serum SHBG have an increased risk of fractures
- 2008
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Ingår i: J Bone Miner Res. - : Wiley. - 1523-4681 .- 0884-0431. ; 23:10, s. 1552-60
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Tidskriftsartikel (refereegranskat)abstract
- Osteoporosis-related fractures constitute a major health concern not only in women but also in men. To study the predictive role of serum sex steroids for fracture risk in men, serum sex steroids were analyzed by the specific gas chromatography-mass spectrometry technique at baseline in older men (n = 2639; mean, 75 yr of age) of the prospective population-based MrOS Sweden cohort. Fractures occurring after baseline were validated (average follow-up of 3.3 yr). The incidence for having at least one validated fracture after baseline was 20.9/1000 person-years. Estradiol (E2; hazard ratio [HR] per SD decrease, 1.34; 95% CI, 1.22-1.49), free estradiol (fE2; HR per SD decrease, 1.41; 95% CI, 1.28-1.55), testosterone (T; HR per SD decrease, 1.27; 95% CI, 1.16-1.39), and free testosterone (fT; HR per SD decrease, 1.32; 95% CI, 1.21-1.44) were all inversely, whereas sex hormone-binding globulin (SHBG; HR per SD increase, 1.41; 95% CI, 1.22-1.63) was directly related to fracture risk. Multivariable proportional hazards regression models, adjusted for age, suggested that fE2 and SHBG (p
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| 27. |
- Moreno, Maiara, 1993-, et al.
(författare)
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Strain and phase evolution in TiAlN coatings during high-speed metal cutting : An in operando high-energy x-ray diffraction study
- 2024
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Ingår i: Acta Materialia. - : Elsevier. - 1359-6454 .- 1873-2453. ; 263
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Tidskriftsartikel (refereegranskat)abstract
- We report on phase and strain changes in Ti1-xAlxN (0 ≤ x ≤ 0.61) coatings on cutting tools during turning recorded in operando by high-energy x-ray diffractometry. Orthogonal cutting of AISI 4140 steel was performed with cutting speeds of 360–370 m/min. Four positions along the tool rake face were investigated as a function of time in cut. Formation of γ-Fe in the chip reveals that the temperature exceeds 727 °C between the tool edge and the middle of the contact area when the feed rate is 0.06 mm/rev. Spinodal decomposition and formation of wurtzite AlN occurs at the positions of the tool with the highest temperature for the x ≥ 0.48 coatings. The strain evolution in the chip reveals that the mechanical stress is largest closest to the tool edge and that it decreases with time in cut for all analyzed positions on the rake face. The strain evolution in the coating varies between coatings and position on the rake face of the tool and is affected by thermal stress as well as the applied mechanical stress. Amongst others, the strain evolution is influenced by defect annihilation and, for the coatings with highest Al-content (x ≥ 0.48), phase changes.
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| 28. |
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| 29. |
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| 30. |
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| 31. |
- Rogström, Lina, 1983-, et al.
(författare)
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Structural changes in Ti1-xAlxN coatings during turning : A XANES and EXAFS study of worn tools
- 2023
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Ingår i: Applied Surface Science. - : Elsevier. - 0169-4332 .- 1873-5584. ; 612
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Tidskriftsartikel (refereegranskat)abstract
- Structural changes in Ti1-xAlxN coated tool inserts used for turning in 316L stainless steel were investigated by XANES, EXAFS, EDS, and STEM. For coarse-grained fcc-structured Ti1-xAlxN coatings, with 0 ≤ x ≤ 0.62, the XANES spectrum changes with Al-content. XANES Ti 1s line-scans across the rake face of the worn samples reveals that TiN-enriched domains have formed during turning in Ti0.47Al0.53N and Ti0.38Al0.62N samples as a result of spinodal decomposition. The XANES spectra reveal the locations on the tool in which the most TiN-rich domains have formed, indicating which part of the tool-chip contact area that experienced the highest temperature during turning. Changes in the pre-edge features in the XANES spectra reveal that structural changes occur also in the w-TiAlN phase in fine-grained Ti0.38Al0.62N during turning. EDS shows that Cr and Fe from the steel adhere to the tool rake face during machining. Cr 1s and Fe 1s XANES show that Cr is oxidized in the end of the contact length while the adhered Fe retains in the same fcc-structure as that of the 316L stainless steel.
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| 32. |
- Salamania, Janella, 1992-, et al.
(författare)
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Elucidating dislocation core structures in titanium nitride through high-resolution imaging and atomistic simulations
- 2022
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Ingår i: Materials & design. - : Elsevier. - 0264-1275 .- 1873-4197. ; 224
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Tidskriftsartikel (refereegranskat)abstract
- Although titanium nitride (TiN) is among the most extensively studied and thoroughly characterizedthin-film ceramic materials, detailed knowledge of relevant dislocation core structures is lacking. Byhigh-resolution scanning transmission electron microscopy (STEM) of epitaxial single crystal (001)-oriented TiN films, we identify different dislocation types and their core structures. These include, besidesthe expected primary a/2{110}h110i dislocation, Shockley partial dislocations a/6{111}h112i and sessileLomer edge dislocations a/2{100}h011i. Density-functional theory and classical interatomic potentialsimulations complement STEM observations by recovering the atomic structure of the different disloca-tion types, estimating Peierls stresses, and providing insights on the chemical bonding nature at the core.The generated models of the dislocation cores suggest locally enhanced metal–metal bonding, weakenedTi-N bonds, and N vacancy-pinning that effectively reduces the mobilities of {110}h110i and {111}h112idislocations. Our findings underscore that the presence of different dislocation types and their effects onchemical bonding should be considered in the design and interpretations of nanoscale and macroscopicproperties of TiN.
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| 33. |
- Salamania, Janella, et al.
(författare)
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High temperature decomposition and age hardening of single-phase wurtzite Ti1−xAlxN thin films grown by cathodic arc deposition
- 2024
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Ingår i: Physical Review Materials. - : AMER PHYSICAL SOC. - 2475-9953. ; 8:1
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Tidskriftsartikel (refereegranskat)abstract
- Wurtzite TmAlN (T-m = transition metal) themselves are of interest as semiconductors with tunable band gap, insulating motifs to superconductors, and piezoelectric crystals. Characterization of wurtzite TmAlN is challenging because of the difficulty to synthesize them as single-phase solid solution and such thermodynamic, elastic properties, and high temperature behavior of wurtzite Ti1-xAlxN is unknown. Here, we investigated the high temperature decomposition behavior of wurtzite Ti1-xAlxN films using experimental methods combined with first-principles calculations. We have developed a method to grow single-phase metastable wurtzite Ti1-xAlxN (x = 0.65, 0.75, 085, and 0.95) solid-solution films by cathodic arc deposition using low duty-cycle pulsed substrate-bias voltage. We report the full elasticity tensor for wurtzite Ti1-xAlxN as a function of Al content and predict a phase diagram including a miscibility gap and spinodals for both cubic and wurtzite Ti1-xAlxN. Complementary high-resolution scanning transmission electron microscopy and chemical mapping demonstrate decomposition of the films after high temperature annealing (950 degrees C), which resulted in nanoscale chemical compositional modulations containing Ti-rich and Al-rich regions with coherent or semicoherent interfaces. This spinodal decomposition of the wurtzite film causes age hardening of 1-2 GPa.
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| 34. |
- Salamania, Janella, et al.
(författare)
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Influence of nitrogen vacancies on the decomposition route and age hardening of wurtzite Ti1−xAlxNy thin films
- 2023
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Ingår i: Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films. - : A V S AMER INST PHYSICS. - 0734-2101 .- 1520-8559. ; 41:6
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Tidskriftsartikel (refereegranskat)abstract
- The wurtzite phase of TiAlN has been known to form in industrial grade coatings with high Al content; yet, a significant knowledge gap exists regarding its behavior at high temperatures and the impact of defects on its properties. Specifically, its response to high temperatures and the implications of defects on its characteristics are poorly understood. Here, the high-temperature decomposition of nitrogen-deficient epitaxial wurtzite Ti1-xAlxNy (x = 0.79-0.98, y = 0.82-0.86) films prepared by reactive magnetron sputtering was investigated using x-ray diffractometry and high-resolution scanning transmission electron microscopy. The results show that wurtzite Ti(1-x)Al(x)Ny decomposes by forming intermediary MAX phases, which then segregate into pure c-TiN and w-AlN phases after high-temperature annealing and intermetallic TiAl nanoprecipitates. The semicoherent interfaces between the wurtzite phase and the precipitates cause age hardening of approximately 4-6 GPa, which remains even after annealing at 1200 degrees C. These findings provide insight into how nitrogen vacancies can influence the decomposition and mechanical properties of wurtzite TiAlN.
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| 35. |
- Salamania, Janella, et al.
(författare)
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Influence of pulsed-substrate bias duty cycle on the microstructure and defects of cathodic arc-deposited Ti1-xAlxN coatings
- 2021
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Ingår i: Surface & Coatings Technology. - : ELSEVIER SCIENCE SA. - 0257-8972 .- 1879-3347. ; 419
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Tidskriftsartikel (refereegranskat)abstract
- The influence of pulsed substrate bias duty cycle on the growth, microstructure, and defects of Ti1-xAlxN coatings grown by cathodic arc deposition was investigated. Ti1-xAlxN coatings of varying compositions (x = 0.56, 0.38, 0.23) were deposited on cemented carbide substrates with 10, 25, 50, and 95% duty cycles of 50 V pulsed-bias under 10 Pa of pure N-2 gas. Coatings grown at low duty cycles (10 and 25%) showed strongly textured, underdense coatings with facetted columns and low amount of lattice defects. Applying higher duty cycles (50 and 95%) produced coatings that have denser microstructures, less preferred orientation, increasing compressive stresses and increased lattice defect densities. Our study elucidates how duty cycle variation not only changes the overall average energy supplied at the growth front but also kinetically influences the coating growth and thus microstructure and defect structure.
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| 36. |
- Sangiovanni, Davide, et al.
(författare)
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Temperature-dependent elastic properties of binary and multicomponent high-entropy refractory carbides
- 2021
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Ingår i: Materials & design. - : Elsevier Science Ltd. - 0264-1275 .- 1873-4197. ; 204
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Tidskriftsartikel (refereegranskat)abstract
- Available information concerning the elastic moduli of refractory carbides at temperatures (T) of relevance for practical applications is sparse and/or inconsistent. Ab initio molecular dynamics (AIMD) simulations at T = 300, 600, 900, and 1200 K are carried out to determine the temperature-dependences of the elastic constants of rocksalt-structure (B1) TiC, ZrC, HfC, VC, TaC compounds, as well as high-entropy (Ti,Zr,Hf,Ta,W)C and (V,Nb, Ta,Mo,W)C. The second-order elastic constants are calculated by least-square fitting of the analytical expressions of stress/strain relationships to simulation results obtained from three tensile and three shear deformation modes. Sound-velocity measurements are employed to validate AIMD values of bulk, shear, and elastic moduli of single-phase B1 (Ti,Zr,Hf,Ta,W)C and (V,Nb,Ta,Mo,W)C at ambient conditions. In comparison with the predictions of previous ab initio calculations - where the extrapolation of finite-temperature elastic properties accounted for thermal expansion while neglecting intrinsic vibrational effects - AIMD simulations produce a softening of shear elastic moduli with T in closer agreement with experiments. The results show that TaC is the system which exhibits the highest elastic resistances to tensile and shear deformation up to 1200 K, and indicate the (V,Nb,Ta,Mo,W)C system as candidate for applications that require superior toughness at room as well as elevated temperatures. (C) 2021 The Author(s). Published by Elsevier Ltd.
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| 37. |
- Siggeirsdottir, K., et al.
(författare)
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The incidence of a first major osteoporotic fracture in Iceland and implications for FRAX
- 2014
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Ingår i: Osteoporosis International. - : Springer Science and Business Media LLC. - 0937-941X .- 1433-2965. ; 25:10, s. 2445-2451
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Tidskriftsartikel (refereegranskat)abstract
- Based on an extensive cohort study over 25 years, the present study supports the assumption that major osteoporotic fractures can be reasonably predicted from hip fracture rates. The construct for FRAX models depends on algorithms to adjust for double counting of fracture outcomes in some models and in others, to estimate the incidence of a major fracture from hip fracture rates. The aim of the present study was to test the validity of these algorithms in a large prospective cohort. The incidence of hip, clinical spine, distal forearm, and humerus fracture was determined in the prospective and ongoing population-based Reykjavik Study with follow up of 257,001 person-years. The incidence of a first major fracture was compared with the correction factors used in FRAX to adjust the incidence of several fracture outcomes for double counting. In addition, the incidence of a major osteoporotic fracture estimated from the Icelandic hip fracture rates was compared with the Malmo ratios used in FRAX. The adjustments necessary to account for multiple fracture outcomes were similar to those previously derived from Sweden. Additionally, incidence of a first major osteoporotic fracture was similar to that derived for FRAX models. The findings of the present study support the algorithms used in FRAX to estimate the incidence of a first major fracture and the predictive value of hip fracture for other major fractures.
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| 38. |
- Vala, CecilieHongslo, 1983, et al.
(författare)
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Increased risk of hip fracture among spouses-evidence of a homogamy effect
- 2017
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Ingår i: Osteoporosis International. - : Springer Science and Business Media LLC. - 0937-941X .- 1433-2965. ; 28:1, s. 95-102
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Tidskriftsartikel (refereegranskat)abstract
- Spouses tend to share habits and therefore have an increased risk of same diseases. We followed all married couples in Sweden, born 1902 to 1942, in hospital records from 1987 to 2002, and found that individuals whose spouse had a hip fracture had an increased risk of hip fracture. INTRODUCTION: The purpose of this study was to determine whether spouses of hip fracture patients have an elevated risk of hip fracture. METHODS: We performed a retrospective cohort study of all couples married for at least 5 years in Sweden and born between 1902 and 1942 (n = 904,451) and all patients registered with a hip fracture (n = 218,285) in the National Inpatients Register in Sweden from 1987 to 2002. RESULTS: During the period 1987 to 2002 hip fractures occurred among spouses in 4212 married couples. The hazard ratio (HR) for hip fracture in a married woman following hip fracture in the husband was 1.11 (95 % confidence interval 1.07 to 1.16) compared to a woman whose husband did not have hip fracture. The corresponding HR for a married man was 1.20 (1.15 to 1.26) compared to a man whose wife did not have hip fracture. The risk was significantly elevated over the age range 60 to 90 years. The increased risk for hip fracture among spouses remained after adjustments for income, education, geographical latitude and urbanisation. In a common model with spouses and their siblings, the HR for spousal effect were 1.63 (1.01 to 2.64) and for sibling effect 2.18 (1.55 to 3.06) compared to married with spouse and sibling respectively without hip fracture. CONCLUSION: The novel finding of an increased risk for hip fracture among spouses provides evidence indicating that there is a homogamy effect due to common social and lifestyle factors but could also be due to assortative mating.
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| 39. |
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| 40. |
- Yalamanchili, K., et al.
(författare)
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Exploring the high entropy alloy concept in (AlTiVNbCr)N
- 2017
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Ingår i: Thin Solid Films. - : Elsevier. - 0040-6090 .- 1879-2731. ; 636, s. 346-352
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Tidskriftsartikel (refereegranskat)abstract
- We have explored the high entropy alloy (HEA) concept in the AlTiVNbCr-nitride material system. (AlTiVNbCr)N coatings synthesized by reactive cathodic arc deposition are close to an ideal cubic solid solution with a positive mean-field enthalpy of mixing of 0.06 eV/atom. First principle calculations showa higher thermodynamic stability for the solid solution relative to their binaries thereby indicating a possible entropy stabilization at a temperature above 727 degrees C. However, the elevated temperature annealing experiments show that the solid solution decomposes to w-AlN and c-(TiVNbCr)N. The limited thermal stability of the solid solution is investigated in relation to several thermodynamic parameters. We suggest that the HEA designed multiprincipal element (AlTiVNbCr) N solid solutions are in a metastable state. (C) 2017 Published by Elsevier B.V.
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| 41. |
- Yazdi, Gholamreza, et al.
(författare)
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Free standing AIN single crystal grown on pre-patterned and in situ patterned 4H-SiC substrates
- 2010
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Ingår i: Materials Science Forum, Vols. 645-648. - : Transtec Publications; 1999. ; , s. 1187-1190
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Konferensbidrag (refereegranskat)abstract
- Free standing AIN wafers were grown on pre-patterned and in situ patterned 4H-SiC substrates by a physical vapor transport method. It is based on the coalescence of AIN microrods, which evolve from the apex of SiC pyramids grown on the SIC substrate during a temperature ramp up for in situ patterned substrate and SiC pyramids formed by reactive ion etching (RIE). This process yields stress-free (according XRD and Raman results) AIN single crystals with a thickness up to 400 mu m and low dislocation density.
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