| 1. |
- Ringsberg, Jonas, 1971, et al.
(författare)
-
MARSTRUCT benchmark study on nonlinear FE simulation of an experiment of an indenter impact with a ship side-shell structure
- 2018
-
Ingår i: Marine Structures. - : Elsevier BV. - 0951-8339. ; 59:1, s. 142-157
-
Tidskriftsartikel (refereegranskat)abstract
- This paper presents a benchmark study on collision simulations that was initiated by the MARSTRUCT Virtual Institute. The objective was to compare assumptions, finite element models, modelling techniques and experiences between established researchers within the field. Fifteen research groups world-wide participated in the study. An experiment involving a rigid indenter penetrating a ship-like side structure was used as the case study. A description of how the experiment was performed, the geometry model of it, and material properties were distributed to the participants prior to their simulations. The paper presents the results obtained from the fifteen FE simulations and the experiment. It presents a comparison of, among other factors, the reaction force versus the indenter displacement, internal energy absorbed by the structure versus the indenter displacement, and analyses of the participants’ ability to predict failure modes and events that were observed in the experiment. The outcome of the study is a discussion and recommendations regarding mesh size, failure criteria and damage models, interpretation of material data and how they are used in a constitutive material model, and finally, uncertainties in general.
|
|
| 2. |
- Sator, Lea, et al.
(författare)
-
Overdiagnosis of COPD in Subjects With Unobstructed Spirometry A BOLD Analysis
- 2019
-
Ingår i: Chest. - : Elsevier BV. - 0012-3692 .- 1931-3543. ; 156:2, s. 277-288
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: There are several reports on underdiagnosis of COPD, while little is known about COPD overdiagnosis and overtreatment. We describe the overdiagnosis and the prevalence of spirometrically defined false positive COPD, as well as their relationship with overtreatment across 23 population samples in 20 countries participating in the BOLD Study between 2003 and 2012.METHODS: A false positive diagnosis of COPD was considered when participants reported a doctor's diagnosis of COPD, but postbronchodilator spirometry was unobstructed (FEV1/FVC > LLN). Additional analyses were performed using the fixed ratio criterion (FEV1/FVC < 0.7).RESULTS: Among 16,177 participants, 919 (5.7%) reported a previous medical diagnosis of COPD. Postbronchodilator spirometry was unobstructed in 569 subjects (61.9%): false positive COPD. A similar rate of overdiagnosis was seen when using the fixed ratio criterion (55.3%). In a subgroup analysis excluding participants who reported a diagnosis of "chronic bronchitis" or "emphysema" (n = 220), 37.7% had no airflow limitation. The site-specific prevalence of false positive COPD varied greatly, from 1.9% in low- to middle-income countries to 4.9% in high-income countries. In multivariate analysis, overdiagnosis was more common among women, and was associated with higher education; former and current smoking; the presence of wheeze, cough, and phlegm; and concomitant medical diagnosis of asthma or heart disease. Among the subjects with false positive COPD, 45.7% reported current use of respiratory medication. Excluding patients with reported asthma, 34.4% of those with normal spirometry still used a respiratory medication.CONCLUSIONS: False positive COPD is frequent. This might expose nonobstructed subjects to possible adverse effects of respiratory medication.
|
|
| 3. |
- Studnicka, Michael, et al.
(författare)
-
COPD : Should Diagnosis Match Physiology?
- 2020
-
Ingår i: Chest. - : Elsevier BV. - 0012-3692 .- 1931-3543. ; 157:2, s. 473-475
-
Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
|
|
| 4. |
- Yu, Suxian, et al.
(författare)
-
Modulating the proton transfer kinetics via Ru single atoms for highly efficient ammonia synthesis
- 2023
-
Ingår i: Chem Catalysis. - : Elsevier BV. - 2667-1107 .- 2667-1093. ; 3:9
-
Tidskriftsartikel (refereegranskat)abstract
- The electrochemical nitrate reduction reaction (eNO3RR) is an appealing technology for converting environmentally toxic NO3− to ammonia (NH3). This approach was usually obstructed by the multi-proton/electron involved process. Here, we report a catalyst with Ru single atoms supported on Co3O4 (Ru SAs-Co3O4). The as-developed Ru SAs-Co3O4 catalyst shows a remarkable NH3-evolving activity with a faradic efficiency of 94.92% ± 4.02% at the potential of −0.2 V (vs. RHE) and a generation rate of 1,843.45 ± 57.14 μmol h−1 cm−2 at the potential of −0.5 V. Further investigations revealed that the Ru SAs play a dual role in simultaneously accelerating the proton transfer and modulating the d-electron structures of the neighboring Co sites, which led to a lower energy barrier of the rate-determining step. Eventually, by combining the eNO3RR and electrosynthesis of 5,5′-azotetrazolate at a two-electrode system, an energy-saving NH3 synthesis, while simultaneously producing value-added chemicals, was successfully achieved.
|
|
