| 1. |
- Lethuillier, A., et al.
(författare)
-
Cometary dust analogues for physics experiments
- 2022
-
Ingår i: Monthly notices of the Royal Astronomical Society. - : Oxford University Press. - 0035-8711 .- 1365-2966. ; 515:3, s. 3420-3438
-
Tidskriftsartikel (refereegranskat)abstract
- The CoPhyLab (Cometary Physics Laboratory) project is designed to study the physics of comets through a series of earth-based experiments. For these experiments, a dust analogue was created with physical properties comparable to those of the non-volatile dust found on comets. This ‘CoPhyLab dust’ is planned to be mixed with water and CO2 ice and placed under cometary conditions in vacuum chambers to study the physical processes taking place on the nuclei of comets. In order to develop this dust analogue, we mixed two components representative for the non-volatile materials present in cometary nuclei. We chose silica dust as a representative for the mineral phase and charcoal for the organic phase, which also acts as a darkening agent. In this paper, we provide an overview of known cometary analogues before presenting measurements of eight physical properties of different mixtures of the two materials and a comparison of these measurements with known cometary values. The physical properties of interest are particle size, density, gas permeability, spectrophotometry, and mechanical, thermal, and electrical properties. We found that the analogue dust that matches the highest number of physical properties of cometary materials consists of a mixture of either 60 per cent/40 per cent or 70 per cent/30 per cent of silica dust/charcoal by mass. These best-fit dust analogue will be used in future CoPhyLab experiments.
|
|
| 2. |
- Darabi, H., et al.
(författare)
-
Development of a novel hybrid multi-boosting neural network model for spatial prediction of urban flood
- 2021
-
Ingår i: Geocarto International. - : Taylor and Francis Ltd.. - 1010-6049 .- 1752-0762.
-
Tidskriftsartikel (refereegranskat)abstract
- In this study, a new hybridized machine learning algorithm for urban flood susceptibility mapping, named MultiB-MLPNN, was developed using a multi-boosting technique and MLPNN. The model was tested in Amol City, Iran, a data-scarce city in an ungauged area which is prone to severe flood inundation events and currently lacks flood prevention infrastructure. Performance of the hybridized model was compared with that of a standalone MLPNN model, random forest and boosted regression trees. Area under the curve, efficiency, true skill statistic, Matthews correlation coefficient, misclassification rate, sensitivity and specificity were used to evaluate model performance. In validation, the MultiB-MLPNN model showed the best predictive performance. The hybridized MultiB-MLPNN model is thus useful for generating realistic flood susceptibility maps for data-scarce urban areas. The maps can be used to develop risk-reduction measures to protect urban areas from devastating floods, particularly where available data are insufficient to support physically based hydrological or hydraulic models.
|
|
| 3. |
- Harnek, Jan, et al.
(författare)
-
Transcatheter Implantation of the MONARC Coronary Sinus Device for Mitral Regurgitation 1-Year Results From the EVOLUTION Phase I Study (Clinical Evaluation of the Edwards Lifesciences Percutaneous Mitral Annuloplasty System for The Treatment of Mitral Regurgitation)
- 2011
-
Ingår i: JACC. Cardiovascular interventions. - : Elsevier BV. - 1936-8798 .- 1876-7605. ; 4:1, s. 115-122
-
Tidskriftsartikel (refereegranskat)abstract
- Objectives This study sought to assess the safety and efficacy of transcatheter valve annuloplasty in patients with mitral regurgitation (MR). Background Mitral regurgitation is associated with a worsened prognosis in patients with dilated cardiomyopathy. Surgical mitral annuloplasty reduces the septal-lateral dimension of the mitral annulus resulting in improved leaflet coaptation with a reduction in regurgitation. Percutaneous annuloplasty with the MONARC device (Edwards Lifesciences, Irvine, California) implanted within the coronary sinus is designed to reduce mitral regurgitation through a similar mechanism. Methods A total of >= 2 patients with MR grade were enrolled at 8 participating centers in 4 countries. Clinical evaluation and transthoracic echocardiography were performed at baseline and at 3, 6, and 12 months. Multislice cardiac computed tomography and coronary angiography were performed at baseline and 3 months. Results The MONARC device was implanted in 59 of 72 patients (82%). The primary safety end point (freedom from death, tamponade, or myocardial infarction at 30 days) was met in 91% of patients at 30 days and in 82% at 1 year. Computed tomography imaging documented passage of the great cardiac vein over an obtuse marginal artery in 55% of patients and was associated with angiographic coronary artery compression in 15 patients and myocardial infarction in 2 patients (3.4%). At 12 months, a reduction in MR by >= 1 grade was observed in 50.0% of 22 implanted patients with matched echocardiograms and in 85.7% of 7 patients with baseline MR >= 3 grade Conclusions Implantation of the MONARC device in the coronary sinus is feasible and may reduce MR. However, coronary artery compression may occur in patients in whom the great cardiac vein passes over a coronary artery, necessitating strategies in future studies to avoid this occurrence.
|
|
| 4. |
|
|
| 5. |
- Kreuzig, C., et al.
(författare)
-
The CoPhyLab comet-simulation chamber
- 2021
-
Ingår i: Review of Scientific Instruments. - : American Institute of Physics (AIP). - 0034-6748 .- 1089-7623. ; 92:11, s. 115102-115102
-
Tidskriftsartikel (refereegranskat)abstract
- The Comet Physics Laboratory (CoPhyLab) is an international research program to study the physical properties of cometary analog materials under simulated space conditions. The project is dedicated to studying, with the help of multiple instruments and the different expertise and background from the different partners, the physics of comets, including the processes inside cometary nuclei, the activity leading to the ejection of dust and gas, and the sub-surface and surface evolution of cometary nuclei when exposed to solar illumination. CoPhyLab will provide essential information on the formation and evolution of comets and insights into the origins of primitive Solar System bodies. To this end, we constructed a new laboratory that hosts several small-scale experiments and a large-scale comet-simulation chamber (L-Chamber). This chamber has been designed and constructed to host ice–dust samples with a diameter of up to 250 mm and a variable height between 100 and 300 mm. The cometary-analog samples will be kept at temperatures below 120 K and pressures around 10−6 mbar to ensure cometary-like conditions. In total, 14 different scientific instruments are attached to the L-Chamber to study the temporal evolution of the physical properties of the sample under different insolation conditions. Due to the implementation of a scale inside the L-Chamber that can measure weight changes of the samples with high precision, the cooling system is mechanically decoupled from the sample holder and cooling of the samples occurs by radiation only. The constructed chamber allows us to conduct uninterrupted experiments at low temperatures and pressures up to several weeks.
|
|
| 6. |
- Lei, Xinxiang, et al.
(författare)
-
Urban flood modeling using deep-learning approaches in Seoul, South Korea
- 2021
-
Ingår i: Journal of Hydrology. - : Elsevier BV. - 0022-1694 .- 1879-2707. ; 601
-
Tidskriftsartikel (refereegranskat)abstract
- Identification of flood-prone sites in urban environments is necessary, but there is insufficient hydraulic information and time series data on surface runoff. To date, several attempts have been made to apply deep-learning models for flood hazard mapping in urban areas. This study evaluated the capability of convolutional neural network (NNETC) and recurrent neural network (NNETR) models for flood hazard mapping. A flood-inundation inventory (including 295 flooded sites) was used as the response variable and 10 flood-affecting factors were considered as the predictor variables. Flooded sites were then spatially randomly split in a 70:30 ratio for building flood models and for validation purposes. The prediction quality of the models was validated using the area under the receiver operating characteristic curve (AUC) and root mean square error (RMSE). The validation results indicated that prediction performance of the NNETC model (AUC = 84%, RMSE = 0.163) was slightly better than that of the NNETR model (AUC = 82%, RMSE = 0.186). Both models indicated that terrain ruggedness index was the most important predictor, followed by slope and elevation. Although the model output had a relative error of up to 20% (based on AUC), this modeling approach could still be used as a reliable and rapid tool to generate a flood hazard map for urban areas, provided that a flood inundation inventory is available.
|
|
| 7. |
- Mirchooli, Fahimeh, et al.
(författare)
-
How do data-mining models consider arsenic contamination in sediments and variables importance?
- 2019
-
Ingår i: Environmental Monitoring & Assessment. - : SPRINGER. - 0167-6369 .- 1573-2959. ; 191:12
-
Tidskriftsartikel (refereegranskat)abstract
- Arsenic (As) is one of the most important dangerous elements as more than 100 million of people are exposed to risk, globally. The permissible threshold of As for drinking water is 10 mu g/L according to both the WHO's drinking water guidelines and the Iranian national standard. However, several studies have indicated that As concentrations exceed this threshold value in several regions of Iran. This research evaluates an As-susceptible region, the Tajan River watershed, using the following data-mining models: multivariate adaptive regression splines (MARS), functional data analysis (FDA), support vector machine (SVM), generalized linear model (GLM), multivariate discriminant analysis (MDA), and gradient boosting machine (GBM). This study considers 12 factors for elevated As concentrations: land use, drainage density, profile curvature, plan curvature, slope length, slope degree, topographic wetness index, erosion, village density, distance from villages, precipitation, and lithology. The susceptibility mapping was conducted using training (70%) and validation (30%). The results of As contamination in sediment showed that classifications into 4 levels of concentration are very similar for two models of GLM and FDA. The GBM calculated the areas of highest arsenic contamination risk by MARS and SVM with percentages of 30.0% and 28.7%, respectively. FDA, GLM, MARS, and MDA models calculated the areas of lowest risk to be 3.3%, 23.0%, 72.0%, 25.2%, and 26.1%, respectively. The results of ROC curve reveal that the MARS, SVM, and MDA had the highest accuracies with area under the curve ROC values of 84.6%, 78.9%, and 79.5%, respectively. Land use, lithology, erosion, and elevation were the most important predictors of contamination potential with a value of 0.6, 0.59, 0.57, and 0.56, respectively. These are the most important factors. Finally, these data-mining methods can be used as appropriate, inexpensive, and feasible options to identify As-susceptible areas and can guide managers to reduce contamination in sediment of the environment and the food chain.
|
|
| 8. |
- Rahmati, Omid, et al.
(författare)
-
TET : An automated tool for evaluating suitable check-dam sites based on sediment trapping efficiency
- 2020
-
Ingår i: Journal of Cleaner Production. - : Elsevier BV. - 0959-6526 .- 1879-1786. ; 266
-
Tidskriftsartikel (refereegranskat)abstract
- Sediment control is important for supplying clean water. Although check dams control sediment yield, site selection for check dams based on the sediment trapping efficiency (TE) is often complex and time-consuming. Currently, a multi-step trial-and-error process is used to find the optimal sediment TE for check dam construction, which limits this approach in practice. To cope with this challenge, we developed a user-friendly, cost- and time-efficient geographic information system (GIS)-based tool, the trap efficiency tool (TET), in the Python programming language. We applied the tool to two watersheds, the Hableh-Rud and the Poldokhtar, in Iran. To identify suitable sites for check dams, four scenarios (S1: TE ≥ 60%, S2: TE ≥ 70%, S3: TE ≥ 80%, S4: TE ≥ 90%) were tested. TET identified 189, 117, 96, and 77 suitable sites for building check dams in S1, S2, S3, and S4, respectively, in the Hableh-Rud watershed, and 346, 204, 156, and 60 sites in S1, S2, S3, and S4, respectively, in the Poldokhtar watershed. Evaluation of 136 existing check dams in the Hableh-Rud watershed indicated that only 10% and 5% were well-located and these were in the TE classes of 80–90% and ≥90%, respectively. In the Poldokhtar watershed, only 11% and 8% of the 207 existing check dams fell into TE classes 80–90% and ≥90%, respectively. Thus, the conventional approach for locating suitable sites at which check dams should be constructed is not effective at reaching suitable sediment control efficiency. Importantly, TET provides valuable insights for site selection of check dams and can help decision makers avoid monetary losses incurred by inefficient check-dam performance.
|
|
| 9. |
|
|
| 10. |
- Werdan, K., et al.
(författare)
-
Curriculum Kardiologie 2., aktualisierte Auflage
- 2020
-
Ingår i: KARDIOLOGE. - : SPRINGER HEIDELBERG. - 1864-9718 .- 1864-9726. ; 14:6, s. 505-536
-
Tidskriftsartikel (refereegranskat)abstract
- The updated second edition of the "Curriculum cardiology", first edition 2013, aims to show which competences a cardiologist should nowadays master. It is very pleasing that in this second edition representatives of the Young German Cardiac Society (Young DGK) have contributed as authors. The increasing specialization within cardiology should, however, only represent one side of the coin: there must also still be a common foundation of cardiology, embedded in the discipline "internal medicine". This foundation includes the basis of theoretical knowledge, practical skills (competence levels I-III) and an occupational and professional attitude of the (prospective) cardiologist. New additions to the advanced training since the first edition of the curriculum in 2013 are, for example a chapter on digital cardiology, the further training in psychocardiology, which was newly introduced into the model further training regulations and finally also the explicit formulation of shared decision making in the interests of cardiac patients. The curriculum should give the prospective cardiologist the possibility to structure the further training as efficiently as possible and ultimately to retain and expand that which has been learned in the sense of a "professional lifelong" qualification. The curriculum also aims to reach the trainers and the Medical Councils and demonstrate which contents and skills should be mediated in the further training to become a cardiologist from the perspective of the German Cardiac Society (DGK).
|
|
