2,455 research outputs found

    Isotopic Study of Siderite Concretion, Tuscarawas County, Ohio

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    Author Institution: Department of Geology and Mineralogy, Ohio State University ; Division of Geological Survey, Ohio Department of Natural Resources, Fountain SquareA carbonate concretion from the shale bed overlying the No. 5 coal of Pennsylvanian age in Tuscarawas County is composed of siderite and contains pyrite, barite, sphalerite and traces of calcite in its interior and in fractures. The siderite has 8I 3C= +0.65%o, Sr=289 ppm and 87Sr/86Sr=0.7110±0.0009- These results indicate that the siderite was deposited from brackish water in the pore spaces of the sediment and discredit the hypothesis that the carbonate ions originated by oxidation of peat or organic material. The barite has 8 S=— 4.6%o, indicating that it was not precipitated from sea water. Pyrite and sphalerite have 8 S= — 10.8%o and — 4.6%o, respectively, and were not deposited in isotopic equilibrium with each other. The sulfur in all three minerals is enriched in l6S as a result of bacterial reduction of sulfate to sulfide

    Estimating adaptive cruise control model parameters from on-board radar units

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    Two new methods are presented for estimating car-following model parameters using data collected from the Adaptive Cruise Control (ACC) enabled vehicles. The vehicle is assumed to follow a constant time headway relative velocity model in which the parameters are unknown and to be determined. The first technique is a batch method that uses a least-squares approach to estimate the parameters from time series data of the vehicle speed, space gap, and relative velocity of a lead vehicle. The second method is an online approach that uses a particle filter to simultaneously estimate both the state of the system and the model parameters. Numerical experiments demonstrate the accuracy and computational performance of the methods relative to a commonly used simulation-based optimization approach. The methods are also assessed on empirical data collected from a 2019 model year ACC vehicle driven in a highway environment. Speed, space gap, and relative velocity data are recorded directly from the factory-installed radar unit via the vehicle's CAN bus. All three methods return similar mean absolute error values in speed and spacing compared to the recorded data. The least-squares method has the fastest run-time performance, and is up to 3 orders of magnitude faster than other methods. The particle filter is faster than real-time, and therefore is suitable in streaming applications in which the datasets can grow arbitrarily large.Comment: Accepted for poster presentation at the Transportation Research Board 2020 Annual Meeting, Washington D.

    Color spaces for computer graphics

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    D7.1 Report on the ECoE research clusters and research groups: management, function and technical capacity

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    This deliverable focuses on the formation of the Eratosthenes Centre of Excellence thematic research clusters of Environment & Climate, the Resilient Society and Big Earth Data Analytics in terms of the operations, research collaborations, tools to facilitate research, agreeing internal structures and allocating staff responsibilities. This deliverable will focus on the integration of recruited research personnel, research equipment and the Strategic Partners’ expertise to meet the needs of the research groups

    Transcatheter Closure of Secundum Atrial Septal Defect Using the Amplatzer Device: Single Center Experience in 140 Patients

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    BACKGROUND: Transcatheter closure of secundum atrial septal defect (ASD) is nowadays widely practiced and has replaced surgical ASD closure in many centers. Improvements in design have made the closure devices retrievable, and reduction in the size of the introduction systems allows interventional treatment even in young patients. In this paper we present our experience with the Amplatzer septal occluder device in patients with ASD. PATIENTS AND METHODS: Between October 2002 and February 2006, 206 consecutive patients with a significant ASD, demonstrated by initial transthoracic echocardiography (TTE), were considered for transcatheter closure with the Amplatzer septal occluder. A total of 156 patients underwent cardiac catheterization, and 140 patients had successful transcatheter ASD closure. Routine examination before catheterization included a standard ECG, a chest x ray, blood tests and TTE. The initial TTE showed the location of the ASD, its septal rim, and its diameter and also helped to measure the length of the interatrial septum in the four-chamber view. These measurements were used to assess the feasibility of transcatheter closure with the Amplatzer device. The “stretched” diameter of the ASD, determined by a balloon sizing catheter, was used to select the diameter of the waist of the device. The size of the selected device was 1 to 2 mm larger than the stretched diameter of the defect. Transesophageal echocardiography was used to monitor the implantation procedure. RESULTS: The Amplatzer device was finally employed in 140 patients for percutaneous closure of ASD. The age of patients ranged between 5.3 and 70 years, median 21.9 years. Procedure time ranged between 25 and 240 minutes, median 60 minutes; fluoroscopy time ranged between 3.5 and 45 minutes, median 12 minutes. The size of the selected device ranged between 6-40 mm. Two devices were implanted in two patients. Serious procedure related complications (embolization and perforation of the left atrial wall) occurred in two cases. At follow up (10 days to 3.4 years, median 2.3 years) complete closure was documented in 97% of this patient group. Unrecognized during implantation, but detected after release, small additional defect with trivial residual shunt was documented in 4 patients. A young critically ill patient, cyanotic due to right-to-left shunt, with complex congenital heart disease developed a brain abscess three months after implantation. CONCLUSION: Percutaneous ASD closure with use of the Amplatzer device in this cohort of 140 patients was highly successful with a low complication rate
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